CN106998168B - Electric working machine - Google Patents

Abstract

An electric working machine in one aspect of the present disclosure includes a motor, a first operation unit, a control unit, a second operation unit, and a storage unit. The storage unit stores the reference speed set via the second operation unit. The control unit drives the motor at a rotation speed corresponding to the drive instruction from the first operation unit according to a control characteristic set based on the reference speed stored in the storage unit.

Description

Electric working machine

Technical Field

The present disclosure relates to an electric working machine provided with a motor as a driving source.

Background

Known electric working machines of this type are provided with a trigger for inputting a command to drive the motor, and are configured to control the rotational speed of the motor in accordance with the amount of operation (in other words, the amount of click) of the trigger by the user.

In the electric working machine, a control characteristic (specifically, an operation amount-rotation speed characteristic) for setting a rotation speed of the motor in accordance with an operation amount of the trigger is set in advance. The rotational speed of the motor is controlled according to the control characteristic.

One example of the electric working machine disclosed in japanese unexamined patent application publication No.2009-285805 has a plurality of control characteristics that are set such that the highest rotational speed at which the operation amount of the trigger becomes maximum is, for example, a low speed, a medium speed, or a high speed.

According to the electric working machine, the user can select the control characteristic for use in the drive control of the motor from the plurality of control characteristics. Therefore, the usability of the electric working machine can be improved.

Disclosure of Invention

As in the above example, in the electric working machine in which the user can select the control characteristic for use in the drive control of the motor from among the plurality of control characteristics, each control characteristic is a fixed characteristic set in advance.

Therefore, the user cannot change the control characteristics for use in the drive control of the motor to the characteristics preferred by the user. The electric working machine cannot be improved to be more convenient for the user.

In one aspect of the present disclosure, it is desirable to be able to provide an electric working machine in which control characteristics for use in drive control of a motor can be arbitrarily set by a user.

An electric working machine in one aspect of the present disclosure includes a motor, a first operation unit, a control unit, a second operation unit, and a storage unit.

The first operation unit is configured to be operated by a user of the electric working machine and configured to output a drive instruction for the motor. The control unit drives the motor at a rotational speed corresponding to the drive instruction from the first operation unit.

The second operation unit is configured to be operated by a user and configured to set a reference speed for driving the motor by the control unit. The storage unit stores the reference speed set via the second operation unit.

The control unit drives the motor at a rotational speed corresponding to the drive instruction from the first operation unit according to a control characteristic set based on the reference speed stored in the storage unit.

Therefore, according to the electric working machine, the control characteristic of the control unit for driving the motor is set based on the reference speed set by the user via the second operation unit. The user is allowed to arbitrarily set the control characteristic by setting the reference speed via the second operation unit. Therefore, the electric working machine is convenient for the user. The operability of the user of the electric working machine can be improved.

The second operation unit may output a setting instruction for the reference speed. The storage unit may store a current rotational speed of the motor being driven as the reference speed when a setting instruction is input from the second operation unit while the control unit drives the motor in response to a driving instruction from the first operation unit.

In this way, the user can operate the second operation unit when the rotational speed becomes a desired rotational speed while checking the rotational state of the motor actually driven by the control unit to store the rotational speed at that time as a reference speed in the storage unit. Therefore, the user can set the desired rotational speed to the reference speed more appropriately. The usability of the electric working machine can be improved.

In this case, each of the control unit and the storage unit may be configured as follows.

When a driving instruction is input from the first operation unit and a setting instruction is input from the second operation unit, the control unit may drive the motor at a rotation speed corresponding to the driving instruction from the first operation unit according to a preset control characteristic for setting.

When a setting instruction is input from the second operation unit while the control unit controls the driving of the motor according to the control characteristic for setting, the storage unit may store the current rotational speed of the motor being driven as the reference speed.

In this way, the user can switch the operation mode of the control unit to the operation mode for driving the motor according to the control characteristic for setting for the reference speed by inputting the setting instruction from the second operation unit.

Thereafter, the user causes the control unit to drive the motor according to the control characteristics for setting by operating the first operation unit, and when the motor becomes a desired rotational speed, a setting instruction is input again from the second operation unit. Therefore, the rotational speed of the motor when the setting command is input again is stored in the storage unit as the reference speed.

Therefore, in this case, the user can set the reference speed to an arbitrary rotational speed by operating the first operation unit. The setting work can be performed more easily and more appropriately.

At this time, in the case where the reference speed is set and thus stored in the storage unit, it is necessary to input the setting instruction twice from the second operation unit. For convenience, the setting instruction may be input when the second operation unit is operated by the user and when the operation is stopped.

For this purpose, the control unit may determine that a setting instruction for the reference speed is input when the second operation unit is operated, and the control unit may drive the motor at a rotational speed corresponding to the driving instruction from the first operation unit according to the control characteristic for setting.

The storage unit may determine that a setting instruction for the reference speed is input when the operation of the second operation unit is stopped while the control unit drives the motor according to the control characteristic for setting, and store the current rotational speed of the motor being driven as the reference speed.

If the control unit and the storage unit are configured as above, the user needs to continuously operate the second operation unit while setting the reference speed.

However, the motor is driven according to the control characteristic for setting only when the user is operating the second operation unit, and the current rotational speed of the motor is stored as the reference speed when the user stops operating the second operation unit. Therefore, the operation of setting the reference speed becomes easy for the user to understand.

In order to input the setting instruction twice from the second operation unit, the setting instruction may be input when the state of the second operation unit is changed from the non-operation state to the operation state by the user's operation.

For this purpose, the control unit may determine that a setting instruction for the reference speed is input when the state of the second operation unit is changed from the non-operation state to the operation state, and initiate drive control for driving the motor at a rotation speed corresponding to the drive instruction from the first operation unit according to the control characteristic for setting.

In addition, the storage unit may determine that a setting instruction for the reference speed is input when the state of the second operation unit is changed from the non-operation state to the operation state again while the control unit controls the driving of the motor according to the control characteristic for setting, and store the current rotational speed of the motor being driven as the reference speed.

If the control unit and the storage unit are configured as above, the user must operate the second operation unit twice when setting the reference speed.

However, during a period of time after the first operation of the second operation unit until the next operation of the second operation unit, it is sufficient for the user to operate only the first operation unit. Therefore, the user can concentrate on adjusting the rotational speed of the motor. Speed adjustment when setting the reference speed to a desired rotational speed becomes easy for the user. The user can perform the adjustment work more optimally.

If the first operation unit is an operation unit by which the user can adjust the click amount (in other words, the operation amount) like the trigger described above, the control unit can control the driving of the motor using the control characteristics including the control characteristics for setting described above. Each of the control characteristics may be an operation amount-rotation speed characteristic.

That is, when each of the control characteristics is an operation amount-rotation speed characteristic, the rotation speed of the motor may be set according to the operation amount of the first operation unit by the user. The control unit controls the driving of the motor so that the motor rotates at the rotational speed.

In this case, the control characteristic for setting may be set such that the lowest rotational speed of the motor in the control characteristic for setting is higher than the lowest rotational speed in the remaining control characteristics in the control characteristic.

That is, even if the lowest rotational speed for the set control characteristic is set to be very low (typically zero (0) rotational speed), similar to the lowest rotational speeds of the remaining control characteristics, it is difficult to adjust the rotational speed of the motor to set the reference speed in a very low speed range.

In addition, the reference speed is intended for use in setting the control characteristic when the control unit controls the driving of the motor. The reference speed may be set to a rotation speed corresponding to an arbitrary operation amount between the lowest rotation speed and the highest rotation speed is sufficient.

Therefore, in setting the reference speed, it is sufficient to be able to adjust the rotational speed in accordance with the operation amount while the motor is rotating in a desired rotational region in which the reference speed can be set. In doing so, the lowest rotational speed for the set control characteristic may be set higher than the lowest rotational speeds of the remaining control characteristics.

In this way, the rotational speed range of the motor, which is changed in response to the operation amount of the first operation unit, is limited to the high rotational speed range of the motor, and is narrower than the case where the rotational speed range is set to the entire speed range of the motor. Therefore, the user can adjust the rotational speed of the motor to be set to the reference speed more finely by the operation of the first operation unit.

On the other hand, the control characteristic for setting may be set such that the highest rotational speed of the motor is the rotational speed at the time of full-speed driving of the motor (i.e., the maximum rotational speed). Thus, the user can set any rotational speed between the lowest rotational speed of the motor as described above and the maximum rotational speed at the time of full-speed driving of the motor as the reference speed.

In addition, the control unit may be configured to select the control characteristic from a plurality of control characteristics that differ in the highest rotational speed of the motor. In this case, the lowest rotational speed of the motor among the control characteristics for setting may be set to the lowest highest rotational speed among the plurality of control characteristics.

In this way, the lowest rotational speed for the set control characteristic may be set to the lowest highest rotational speed among the remaining control characteristics of the plurality of control characteristics. Thus, the reference speed can be set in a range in which the rotational speed is higher than the minimum maximum rotational speed. Therefore, the range of the rotational speed that can be set as the reference speed is limited to the practical range. Within this range, the reference speed can be set more finely.

The control characteristic for setting may be set such that the rotational speed of the motor is linearly changed in proportion to the operation amount of the first operation unit.

In this case, when the user operates the first operation unit to set the reference speed, the rotational speed of the motor is changed in a one-to-one manner (in other words, proportionally) in response to the operation amount. Therefore, the user can easily set the reference speed by the operation of the first operation unit.

In addition, the control unit may be configured to report that the motor can be driven and controlled according to the control characteristics for setting.

Thus, the user can check by report from the control unit that: the reference speed may be set to a desired rotation speed by operating the first operating unit to drive the motor. The usability of the electric working machine can be improved.

On the other hand, in setting the reference speed, it is not always necessary for the user to operate the first operation unit to adjust the rotational speed of the motor. The control unit may automatically change the rotational speed of the motor.

More specifically, for example, when a setting instruction for the reference speed is input from the second operation unit, the control unit may drive the motor such that the rotational speed of the motor is changed between the lowest rotational speed for setting and the highest rotational speed for setting based on a preset variation characteristic for setting.

When a setting instruction for a reference speed is input from the second operation unit while the control unit drives the motor based on the variation characteristic for setting, the storage unit may store the current rotational speed of the motor being driven as the reference speed.

In this way, the user can also select an arbitrary rotational speed to be set as the reference speed from among rotational speeds of the motor that vary when the control unit drives the motor based on the variation characteristic for setting, for setting the reference speed.

In this case, the variation characteristic for setting may be set such that the rotational speed of the motor is periodically changed from the lowest rotational speed for setting to the highest rotational speed for setting, or from the highest rotational speed for setting to the lowest rotational speed for setting, or from both the lowest rotational speed for setting to the highest rotational speed for setting and from the highest rotational speed for setting to the lowest rotational speed for setting.

At this time, the reference speed stored in the storage unit is used to set such a control characteristic: the control characteristic is used in controlling the driving of the motor by the control unit. The setting of the control characteristic may be performed when the reference speed is stored in the storage unit.

In this way, immediately after the reference speed is stored in the storage unit and the control characteristic is set, the control unit can perform drive control of the motor based on the control characteristic. The control characteristics of the motor can be switched without stopping the driving of the motor.

In addition, when the reference speed is stored in the storage unit and then the output of the drive instruction from the first operation unit is stopped, the control unit may set the control characteristic to be set based on the reference speed stored in the storage unit as the control characteristic for use in performing the drive control of the motor.

In this case, the user stops the driving of the motor once after driving the motor to store the reference speed in the storage unit, and then may drive and control the motor using a new control characteristic set based on the reference speed when operating the first operation unit to drive the motor again.

In addition, the control unit may stop the rotation of the motor when the reference speed is stored in the storage unit.

In this case, when the motor is driven to store the reference speed in the storage unit, the driving of the motor is stopped. Therefore, the user can check that the reference speed is stored in the storage unit by the stop of the motor. Thereafter, the user may operate the first operating unit to drive the motor again, thereby driving and controlling the motor using the new control characteristics.

The control unit may report that the motor can be driven and controlled when the reference speed is stored in the storage unit and the motor can be driven and controlled according to a control characteristic set based on the reference speed.

In this way, the user can check, through a report from the control unit, that the motor can be driven and controlled according to the control characteristics set by the user. The usability of the electric working machine can be improved.

At this time, the control unit may select one of at least one normal mode and a set mode as an operation mode for the control unit, and the control unit may drive the motor in the selected operation mode.

Here, the at least one normal mode may be a mode for drive-controlling the motor at a rotational speed corresponding to a drive instruction from the first operation unit according to at least one preset fixed control characteristic.

The setting mode may be a mode for controlling the driving of the motor in correspondence with the drive instruction from the first operating unit in accordance with a variable control characteristic that is set based on the reference speed stored in the storage unit.

Therefore, if the control unit is configured as such, the user can control the rotational speed of the motor according to a predetermined fixed control characteristic by operating the first operating unit. The user may also cause the control unit to control the rotational speed of the motor according to a variable control characteristic set based on a reference speed defined via the second operating unit.

Therefore, according to the electric working machine having such a control unit, the user can select the variation characteristic of the rotational speed of the motor, in which the rotational speed is changed in correspondence with the operation of the first operation unit, from the control characteristics, and furthermore, the user can arbitrarily change one of the control characteristics to the control characteristic preferred by the user.

Therefore, the usability of the electric working machine can be further improved.

The electric working machine may include a third operating unit configured to be operated by a user to switch an operation mode of the control unit to the at least one regular mode. The control unit may be configured such that the operation mode is switched to the at least one normal mode when the third operation unit is operated, and such that the operation mode is switched to the set mode when the second operation unit is operated.

In this case, the second operation unit and the third operation unit may be provided side by side in an operation area of the electric working machine (for example, in an operation panel or the like). In this way, the user can selectively operate one of the second operation unit and the third operation unit by simply moving the finger, thereby easily switching the operation mode of the control unit.

The distance between the second operation unit and the third operation unit may be longer than a length of at least one of the second operation unit and the third operation unit in an arrangement direction of the second operation unit and the third operation unit.

In other words, if the second operation unit and the third operation unit are set as such, it is possible to suppress erroneous operation of the second operation unit or the third operation unit caused by the user when the operation mode of the control unit is switched.

A display unit configured to display a state of the electric working machine may be provided between the second operation unit and the third operation unit.

Drawings

Exemplary embodiments of the present disclosure will hereinafter be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a perspective view showing an appearance of an electric power tool according to an embodiment;

fig. 2 is a schematic diagram of a configuration of an operation panel provided to the electric power tool;

fig. 3 is a block diagram showing a circuit configuration of a motor driver provided in the electric power tool;

fig. 4 is a line graph showing control characteristics when the motor is driven and controlled;

FIG. 5 is a flowchart showing a control process performed in the control circuit of FIG. 3;

fig. 6 is a flowchart showing a mode setting process performed in S140 of fig. 5;

fig. 7 is a flowchart showing a rotational speed setting storage process executed in S150 of fig. 5;

fig. 8 is a flowchart showing a motor control process performed in S160 of fig. 5;

fig. 9 is a flowchart showing a display process performed in S170 of fig. 5;

fig. 10 is a flowchart showing a rotational speed setting storage process of the first modification;

fig. 11 is a flowchart showing a motor control process of a first modification;

fig. 12 is a flowchart showing a rotational speed setting storage process of a second modification; and

fig. 13 is a flowchart showing a rotational speed setting storage process of the third modification.

Detailed Description

In the present embodiment, the electric power tool 1 is described as an example of the electric working machine of the present disclosure. In the following description, the rotation speed of the motor (specifically, the number of revolutions per unit time of the motor) is simply referred to as the rotation speed. In addition, the switch is sometimes simply referred to as SW.

As shown in fig. 1, the electric power tool 1 of the present embodiment is a rechargeable impact driver. The electric power tool 1 includes a body housing 5, the body housing 5 being configured by assembling the right and left housing halves 2 and 3 and being equipped with a grip portion 4 extending downward. The battery pack 6 is detachably mounted to the lower end of the grip portion 4 of the body case 5.

A motor housing 7 for accommodating a motor 40 (see fig. 3) is provided in a rear portion (on the left side in fig. 1) of the body housing 5, wherein the motor 40 serves as a drive source of the electric power tool 1. The front portion of the motor housing 7 houses a reduction mechanism and a striking mechanism.

At the distal end of the body housing 5, a chuck sleeve 8 is provided for attaching various tool bits (not shown), such as a driver bit and a casing bit, to the front end of the striking mechanism.

The striking mechanism includes, for example, a spindle that rotates via a speed reduction mechanism, a hammer that rotates together with the spindle and is movable in the axial direction, and an anvil located in front of the hammer. The tool head is attached to the front end of the anvil. The striking mechanism operates as follows.

That is, in the striking mechanism, when the spindle is rotated with the rotation of the motor 40, the anvil is rotated via the hammer to rotate the chuck sleeve 8 (and thus the tool head).

When the screwing by the tool head progresses and the load on the anvil increases, the hammer moves backward against the biasing force of the coil spring and disengages from the anvil, and then moves forward due to the biasing force of the coil spring while rotating together with the spindle to reengage with the anvil.

Thus, intermittent blows are applied to the anvil and the screw is further tightened by the tool head. It should be noted that the striking mechanism is known from the prior art, and the details of the striking mechanism are disclosed in, for example, japanese unexamined patent application publication No.2006-0218605, the entire disclosure of which is incorporated herein by reference.

The grip portion 4 is a portion that the user grips when using the electric power tool 1. The upper side of the grip 4 is provided with a trigger SW 10.

The flip-flop SW 10 functions as the above-described first operation unit. The trigger SW 10 includes a trigger that is pulled by a user, and a circuit unit that is turned on when the trigger is pulled and whose resistance value changes according to the amount of pull-out (operation amount).

In addition, the upper side of the trigger SW 10 is provided with a forward-reverse switching SW 12 for switching the rotational direction of the motor 40 to a forward direction (for example, a clockwise direction when the tool is viewed from the rear end side) or a reverse direction (a rotational direction reverse to the forward direction).

In addition, the distal end side of the body housing 5, on which the chuck sleeve 8 is provided, is provided with an illumination LED 14 for illuminating the front of the power tool 1 with light when the trigger SW 10 is pulled.

In the grip portion 4, an operation panel 20 is provided in a front upper portion of a mounting portion to which the battery pack 6 is mounted, the operation panel 20 being used, for example, to switch an operation mode of the electric power tool 1 and to display the operation mode and a remaining energy of the battery pack 6.

The battery pack 6 is mounted to the mounting portion by sliding from the front side to the rear side of the mounting portion at the lower end of the grip portion 4.

As shown in fig. 2, the operation panel 20 is provided with a normal mode setting SW 22, a rotational speed setting SW24, an illumination SW 26, a normal mode display 32, a setting mode display 34, and a remaining energy display 36.

The normal mode setting SW 22, the rotational speed setting SW24, and the illumination SW 26 are automatic reset type button switches that are normally in an "off" state and will be in an "on" state when depressed by a user's finger. In the present embodiment, a so-called tactile switch is used.

The normal mode setting SW 22 is used to set the operation mode of the electric power tool 1 to a normal mode in which the motor 40 is driven and controlled using one of the high speed fixed control characteristic, the medium speed fixed control characteristic, and the low speed fixed control characteristic. The normal mode setting SW 22 functions as the above-described third operation unit.

In this embodiment, the control characteristic of the motor 40, which is a characteristic of the rotational speed with respect to the operation amount, is used to set the rotational speed of the motor 40 in response to the operation amount of the trigger SW 10 (the amount of the trigger being pulled).

The high-speed fixed control characteristic, the medium-speed fixed control characteristic, and the low-speed fixed control characteristic for use in the normal mode have linear characteristics such that the rotation speed of the motor 40 is proportional to the trigger actuation amount expressed as a numerical value (in other words, resolution) of 0 to 20, as shown in fig. 4.

Each of these fixed control characteristics is set such that the lowest rotational speed when the trigger pull-out amount is the minimum value (0) is "0", and such that the corresponding highest rotational speeds when the trigger pull-out amount is the maximum value (20) are high speed, medium speed, and low speed.

Since each of the fixed control characteristics is linear, the line graph in fig. 4 shows a linear shape obtained by connecting the lowest rotational speed and the corresponding highest rotational speed with a straight line. In fig. 4, the rotational speed is represented by a percentage (%) where the maximum rotational speed of the motor 40 at the full speed driving is 100%.

When the normal mode setting SW 22 is operated, the latest normal mode (one of high speed, middle speed, and low speed) previously selected is selected. Thereafter, when the normal mode setting SW 22 is operated, the normal mode (in other words, the fixed control characteristic) of the motor 40 is switched in order, for example, from the high speed to the medium speed, from the medium speed to the low speed, from the low speed to the high speed … … at each operation.

At this time, the normal mode display 32 is used to display the type of the fixed control characteristic (high speed, medium speed, or low speed) switched by the operation of the normal mode setting SW 22. In this embodiment, the conventional mode display 32 includes three LEDs.

In other words, each of the three LEDs corresponds to a fixed control characteristic of one of the high speed, the middle speed, and the low speed of the conventional mode. The LED corresponding to the fixed control characteristic selected by the operation of the normal mode setting SW 22 is turned on. The other LEDs are turned off.

The rotational speed setting SW24 is used to switch the operation mode of the electric power tool 1 to a setting mode in which the user controls the drive of the motor 40 using a variable control characteristic that can be arbitrarily set by the user. The rotational speed setting SW24 is also used for allowing the user to set a variable control characteristic for use in the drive control of the motor 40 in the setting mode. The rotational speed setting SW24 functions as the above-described second operation unit.

That is, in the present embodiment, when the rotational speed setting SW24 is operated while the operation mode of the electric power tool 1 is the setting mode, the motor 40 is driven and controlled using the control characteristic for setting shown in fig. 4 while the operation is continued.

Then, when the operation of the rotational speed setting SW24 is stopped, the rotational speed of the motor 40 at this time (NA, NB, etc. shown in fig. 4) driven and controlled according to the characteristic for setting is stored as the reference speed of the variable control characteristic.

The stored reference speed is used as a variable control characteristic (A, B, etc. shown in fig. 4) for setting the lowest rotational speed, which is the same as the lowest rotational speed of the fixed control characteristic, to "0" as the highest rotational speed of the variable control characteristic. Thereafter, in the set mode, the motor 40 is driven and controlled using the set variable control characteristic.

Among the control characteristics for setting, the lowest rotational speed is set to coincide with the highest rotational speed of the low-speed fixed control characteristic in which the highest rotational speed is the lowest in the normal mode.

Further, the maximum rotational speed during full-speed driving of the motor 40 (100% rotational speed shown in fig. 4) is set to the highest rotational speed for the set control characteristic, as in the high-speed fixed control characteristic in which the highest rotational speed is the highest in the normal mode.

The control characteristic for setting is set in advance as the following linear characteristic: in the linear characteristic, the lowest rotational speed is a rotational speed at which the trigger SW 10 is operated by the lowest operation amount (for example, the trigger latch amount is 1 or 2), and the linear characteristic connects the lowest rotational speed and the highest rotational speed (the maximum rotational speed of the motor 40) by a straight line.

The setting mode display 34 includes an LED for displaying that the operation mode of the power tool 1 is the setting mode. By operating the trigger SW 10 in the setting mode, the LED is caused to blink when the motor 40 can be driven and controlled using the control characteristic for setting, and the LED is caused to light up when the motor 40 can be driven and controlled using the variable control characteristic.

The illumination SW 26 is used to switch between lighting the illumination LED 14 and not lighting the illumination LED 14 in conjunction with the operation of the trigger SW 10. If the illumination LED 14 is set not to be turned on by the illumination SW 26, the illumination LED 14 is not turned on even if the trigger SW 10 is operated.

The remaining energy display 36 includes at least one LED (see fig. 3) for displaying the remaining energy of the battery 60 in the battery pack 6. The remaining energy display 36 displays the remaining energy by, for example, lighting or blinking of an LED, a blinking time period, switching of a light color, or the like.

It should be noted that the remaining energy of the battery 60 is the amount of charge remaining in the battery 60.

In the operation panel 20, the rotational speed setting SW24, the remaining energy display 36, the illumination SW 26, and the normal mode setting SW 22 are sequentially arranged in a line, for example, from the left end of the operation panel 20 to the right end of the operation panel 20.

The provision of the remaining energy display 36 and the illumination SW 26 between the rotational speed setting SW24 and the normal mode setting SW 22 can prevent the simultaneous operation of the rotational speed setting SW24 and the normal mode setting SW 22 or the erroneous operation of operating a switch different from a certain switch. Therefore, erroneous switching of the operation mode of the electric power tool 1 due to erroneous operation of the rotational speed setting SW24, the normal mode setting SW 22 can be prevented.

In the present embodiment, the remaining energy display 36 and the illumination SW 26 are provided between the rotational speed setting SW24 and the normal mode setting SW 22. However, merely providing a display unit such as the remaining energy display 36 may prevent erroneous operation of the corresponding SW 22, 24.

Further, to prevent an erroneous operation, the rotational speed setting SW24 and the normal mode setting SW 22 may be provided only at predetermined intervals. However, in this case, if the interval is short, erroneous operation may easily occur. The interval between the rotational speed setting SW24 and the normal mode setting SW 22 may be set longer than the length of the respective rotational speed setting SW24 and normal mode setting SW 22 in the direction in which the rotational speed setting SW24 and normal mode setting SW 22 are provided (specifically, the width of an operation region for pressing the respective switches 24, 22, which is approximately 10mm or more).

The battery 60 housed in the battery pack 6 is a rechargeable battery, such as a lithium ion battery, which can be repeatedly recharged. However, the battery 60 is not limited thereto.

In the present embodiment, the motor 40 is a three-phase brushless motor having an armature winding of each of U-phase, V-phase, and W-phase. However, the motor 40 is not limited thereto. The motor 40 is provided with a rotation sensor 42 (see fig. 3) for detecting a rotational position (angle) of the motor 40.

The rotation sensor 42 in the present embodiment is a hall IC (integrated circuit) having three hall elements. However, the rotation sensor 42 is not limited thereto. Each of the hall elements is disposed corresponding to a different phase of the motor 40. The rotation sensor 42 generates three rotation detection signals each having a predetermined electrical angle each time the motor 40 rotates by a predetermined angle.

A motor driver 50 (see fig. 3) is provided within the grip portion 4, the motor driver 50 receiving a supply of electric power from a battery 60 in the battery pack 6 to control the driving of the motor 40.

As shown in fig. 3, the motor driver 50 is provided with a drive circuit 52, a gate circuit 54, a control circuit 56, and a regulator 58.

The drive circuit 52 is configured to receive power from the battery 60 to flow current to each phase winding of the motor 40. More specifically, the drive circuit 52 of the present embodiment is a three-phase full bridge circuit having six switching elements Q1 to Q6. However, the drive circuit 52 is not limited to a three-phase full bridge circuit. Further, in the present embodiment, each of the switching elements Q1 to Q6 is a MOSFET (metal oxide semiconductor field effect transistor). However, the switching elements Q1 to Q6 are not limited to MOSFETs.

In the drive circuit 52, each of the three switching elements Q1 to Q3 is provided as a so-called high-side switch between each of the corresponding terminals U, V and W of the motor 40 and a power supply line coupled to the positive electrode of the battery 60.

Each of the other three switching elements Q4 to Q6 is provided as a so-called low-side switch between each of the corresponding terminals U, V and W of the motor 40 and a ground line coupled to a negative electrode of the battery 60.

The gate circuit 54 turns on/off each of the switching elements Q1 to Q6 in the drive circuit 52 according to a plurality of control signals output from the control circuit 56 to flow a current to each phase winding of the motor 40, thereby rotating the motor 40.

The control circuit 56 in the present embodiment is provided with a microcomputer including a CPU, a ROM, a RAM, and the like. The control circuit 56 is also provided with a nonvolatile memory 57 for storing various parameters necessary for controlling the driving of the motor 40.

It should be noted that the parameters stored in the nonvolatile memory 57 further include: a high-speed fixed control characteristic, a medium-speed fixed control characteristic and a low-speed fixed control characteristic in a conventional mode; a control characteristic and a variable control characteristic for setting in the setting mode; and a reference speed (highest rotation speed) of the variable control characteristic.

The above-mentioned trigger SW 10, forward-reverse switching SW 12, illumination LED 14, and operation panel 20 (more specifically, various SWs 22, 24, 26 provided on the operation panel 20 and displays 32, 34, 36 for various states) are coupled to the control circuit 56. In the control circuit 56, instead of a microcomputer, the function of the microcomputer may be realized by a combination of separate electronic components, may be realized by an ASIC (application specific integrated circuit), may be realized by a programmable logic device such as an FPGA (field programmable gate array), or may be realized by any combination of separate electronic components, an ASIC, and a programmable logic device.

Further, in the motor driver 50, a current detection circuit 44 for detecting a current flowing through the motor 40 is provided in a conductive path extending from the drive circuit 52 to a negative electrode of the battery 60. The current detection circuit 44 includes, for example, a resistor for current detection and an input circuit for inputting a voltage between both ends of the resistor to the control circuit 56 as a current detection signal.

The motor driver 50 also includes a battery voltage detector 46 for detecting a power supply voltage (battery voltage) from the battery 60.

A rotation detection signal from a rotation sensor 42 provided in the motor 40, a current detection signal from a current detection circuit 44, and a voltage detection signal from a battery voltage detector 46 are also input to the control circuit 56.

The control circuit 56 acquires or calculates the rotational position and the rotational speed of the motor 40 based on the rotation detection signal from the rotation sensor 42 when the trigger SW 10 is operated, and drives the motor 40 in a predetermined rotational direction according to the rotational direction setting signal from the forward-reverse switch SW 12.

Further, the control circuit 56 acquires or calculates a rotational speed as a control target of the motor 40 based on the control characteristic corresponding to the operation mode set by the operation of the normal mode setting SW 22 or the operation of the rotational speed setting SW24 and the operation amount of the trigger SW 10, thereby setting the rotational speed command value of the motor 40.

Subsequently, the control circuit 56 acquires or calculates a drive duty ratio of each of the switching elements Q1 to Q6 in the drive circuit 52 based on the rotational speed command value, and outputs a plurality of control signals (PWM (pulse width modulation) signals) to the gate circuit 54 in accordance with the drive duty ratio, thereby controlling the rotational speed of the motor 40.

Therefore, independently of the control procedure for driving the motor 40 as such, the control circuit 56 also performs control of lighting up the illumination LEDs 14 during driving of the motor, control of lighting up the remaining energy display 36 in accordance with the remaining energy in the battery 60, and the like.

The regulator 58 receives a supply of power from a battery 60 to generate a constant supply voltage Vcc (e.g., 5V Direct Current (DC)) required for operating the control circuit 56. The control circuit 56 receives a power supply voltage Vcc from the regulator 58 to operate.

Now, a description will be given of a control process performed by the control circuit 56.

As shown in fig. 5, the control circuit 56 repeatedly executes a series of processes of S120 to S170(S denotes a step) at a predetermined control cycle (time base).

That is, in S110, the control circuit 56 waits for the elapse of the predetermined control time period by determining whether the time base has elapsed. When it is determined in S110 that the time base has elapsed, the process moves to S120.

In S120, the control circuit 56 performs the following switching operation detection process: in this switch operation detection process, signal inputs from the flip-flop SW 10, the forward-reverse switching SW 12, the normal mode setting SW 22, and the rotational speed setting SW24 are checked, and the operated state of each of these switches is detected.

In S130, the following a/D conversion (analog-to-digital conversion) process is performed: in this a/D conversion process, the operation amount of the flip-flop SW 10 and the detection signals from the current detection circuit 44 and the battery voltage detector 46 are a/D converted and retrieved.

In the following S140, the following mode setting process is performed: the mode setting process is for setting the operation mode to a normal mode of high speed, medium speed and low speed, or to a set mode, according to the operation states of the normal mode setting SW 22 and the rotational speed setting SW 24.

In S150, the following rotational speed setting storage process is executed: the rotational speed setting storage process is for storing in the nonvolatile memory 57 a reference speed (i.e., the highest rotational speed of the variable control characteristic) required to generate the variable control characteristic used in controlling the driving of the motor 40 in the setting mode.

In S160, the following motor control process is executed: the motor control process is for controlling the drive of the motor 40 at a rotational speed corresponding to the operation amount of the trigger SW 10 according to the control characteristics corresponding to the operation mode set by the operations of the normal mode setting SW 22 and the rotational speed setting SW 24.

Finally, in S170, the following display process is performed: in this display process, the operation mode of the electric power tool 1 and the setting state of the variable control characteristic are displayed by lighting or blinking the LED of the normal mode display 32 or the LED of the setting mode display 34 of the operation panel 20. Subsequently, the process proceeds to S110.

Now, a mode setting process performed in S140 of fig. 5 will be described.

As shown in fig. 6, in the mode setting process, first in S210, it is determined whether the currently set operation mode is the normal mode. If the operation mode is the normal mode, the process proceeds to S220 to determine whether the state of the normal mode setting SW 22 has been changed from the non-operation state (hereinafter referred to as the "off state) to the operation state (hereinafter referred to as the" on "state).

In S220, if it is determined that the state of the normal mode setting SW 22 has been changed from the "off" state to the "on" state (in other words, the normal mode setting SW 22 is operated), the process moves to S230 to change the setting of the fixed control characteristic used in the normal mode. Subsequently, the mode setting process is terminated.

The setting change of the fixed control characteristic in S230 is performed by switching the fixed control characteristic from high speed to medium speed, from medium speed to low speed, and from low speed to high speed in a sequential manner each time the normal mode setting SW 22 is operated.

On the other hand, if it is determined in S220 that the normal mode setting SW 22 has not been operated, the process moves to S240 to determine whether the state of the rotational speed setting SW24 has changed from the "off" state to the "on" state (in other words, whether the rotational speed setting SW24 has been operated).

In S240, if it is determined that the rotational speed setting SW24 has been operated, the process proceeds to S250 to change the operation mode from the normal mode to the set mode. Subsequently, the mode setting process is terminated. Further, in S240, if it is determined that the rotational speed setting SW24 is not operated, the mode setting process is immediately terminated.

In S210, when it is determined that the currently set operation mode is not the normal mode (i.e., when the operation mode is the set mode), the process proceeds to S260.

In S260, it is determined whether the state of the normal mode setting SW 22 has changed from the "off" state to the "on" state (in other words, whether the normal mode setting SW 22 is operated).

In S260, when it is determined that the normal mode setting SW 22 is operated, the process proceeds to S270. The operation mode is changed from the set mode to the normal mode. The mode setting process is terminated.

In S260, when it is determined that the normal mode setting SW 22 is not operated, the mode setting process is immediately terminated.

Now, a description will be given of the rotational speed setting storage process performed in S150 of fig. 5.

As shown in fig. 7, in the rotational speed setting storage process, it is first determined whether the currently set operation mode is the set mode in S310.

If the operation mode is the setting mode, the process proceeds to S320 to determine whether the rotation speed setting SW24 is operated by the user and whether the rotation speed setting SW24 is in the "on" state (in other words, whether a setting instruction for the reference speed is input).

In S320, if it is determined that the rotational speed setting SW24 is in the on state, the process proceeds to S330 to select a control characteristic for setting from the control characteristics stored in the nonvolatile memory 57 as a control characteristic for use in the current setting mode. The rotational speed setting storage process is then terminated.

On the other hand, in S320, if it is determined that the rotational speed setting SW24 is in the off state, the process proceeds to S340 to select a variable control characteristic from the control characteristics stored in the nonvolatile memory 57 as a control characteristic for use in the current setting mode. The process proceeds to S350.

In S350, it is determined whether the rotational speed setting SW24 is determined to be in the "on" state in S320 of the previous rotational speed setting storage process and whether the determination result in S320 of this time is changed to the "off" state. In S350, it is determined whether the rotational speed setting SW24 changes from the "on" state to the "off" state, and the setting instruction for the reference speed is input again.

In S350, if it is determined that the rotational speed setting SW24 has just changed to the off state, the process proceeds to S360 to store the current rotational speed command value of the motor 40 (in other words, the rotational speed of the motor 40) in the nonvolatile memory 57 as the reference speed. The process proceeds to S370.

In S370, a variable control characteristic is generated (in other words, updated), with the reference speed stored in the nonvolatile memory 57 in S360 as the highest rotation speed, which is then stored in the nonvolatile memory 57. Thereafter, the rotational speed setting storage process is terminated.

In S310, when it is determined that the currently set operation mode is not the setting mode, or when it is determined in S350 that the rotational speed setting SW24 has not just changed to the off state, the rotational speed setting storage process is terminated.

Now, a motor control process performed in S160 of fig. 5 will be described.

As shown in fig. 8, when the motor control process is started, it is first determined in S410 whether the trigger SW 10 is operated by the user and the trigger SW 10 is in the on state. If the flip-flop SW 10 is in the ON state, the process proceeds to S420.

In S420, it is determined whether to drive the motor 40 based on the operation amount of the trigger SW 10 and the state of the battery 60 or the motor 40. When it is determined to drive the motor 40, the process proceeds to S430 to perform a motor driving process.

The motor driving process is the following process: this process is for controlling the drive of the motor 40 so that the rotational speed of the motor 40 is the target rotational speed determined by the operation amount of the trigger SW 10 and the control characteristic set in the current operation mode (normal mode or set mode).

That is, in the motor driving process, the target rotational speed as the control target of the motor 40 as described above is acquired or calculated to set the rotational speed command value. Based on the rotation speed command value, a drive duty is obtained or calculated to output the plurality of control signals (PWM signals) to the gate circuit 54 in accordance with the drive duty. After the motor driving process is performed, the motor control process is temporarily terminated.

On the other hand, in S410, if it is determined that the trigger SW 10 is not in the on state, the process proceeds to S440 to execute a motor stop process, and the motor control process is ended. In the motor stop process in S440, the motor 40 is stopped by generating a braking force to the motor 40 via the drive circuit 52 or cutting off only the power supply to put the motor 40 in a free running state.

Now, a description will be made of the display process performed in S170 of fig. 5.

As shown in fig. 9, in the display process, it is first determined in S510 whether the operation mode currently set is the normal mode.

If the operation mode is the normal mode, the process moves to S520 to turn off the LED of the setting mode display 34. Subsequently, the process proceeds to S530, and the display process is ended after one of the LEDs of the normal mode display 32 is lighted.

Lighting up one of the LEDs of the normal mode display 32 in S530 is performed by turning on one of the LEDs of the three LEDs of the normal mode display 32 corresponding to the fixed control characteristic of the high speed, the middle speed, or the low speed selected in the normal mode.

In S510, when it is determined that the operation mode is not the normal mode (i.e., the operation mode is the setting mode), the process proceeds to S540 to determine whether the control characteristic of the motor 40 currently selected is the control characteristic for setting.

If the currently selected control characteristic is the control characteristic for setting, the process proceeds to S550 to activate blinking control for turning on and off the LED of the setting mode display 34 for a certain blinking time period. The process proceeds to S560.

Such blinking control is a process for notifying the user that the motor 40 can be driven and controlled using the control characteristics for setting. In response to the blinking of the LED of the setting mode display 34 achieved through this process, the user operates the trigger SW 10 and adjusts the rotation speed of the motor 40. This allows the user to arbitrarily set and check the driving characteristics of the motor 40.

In S540, when it is determined that the currently selected control characteristic is not the control characteristic for setting (i.e., the currently selected control characteristic is the variable control characteristic), the process proceeds to S570 to light up the LEDs of the setting mode display 34. The process then moves to S560. In S560, the LED of the normal mode display 32 is turned off. The display process terminates.

It should be noted that since the LED of the setting mode display 34 is lit through the process of S570, the user can check: the motor 40 can be driven by a driving characteristic set by a user by operating the trigger SW 10.

As described above, the electric power tool 1 of the present embodiment is configured to be able to switch the operation mode to the normal mode for controlling the drive of the motor 40 by the fixed control characteristic or the setting mode for controlling the drive of the motor 40 with the variable control characteristic.

The variable control characteristic for use in the setting mode is generated by using the following rotational speeds as reference speeds: the rotational speed is specified by the user operating the rotational speed setting SW 24. Therefore, the user can arbitrarily set the variable control characteristic. The usability of the electric power tool 1 in the set mode can be improved.

Further, in the setting mode, when the user operates the rotational speed setting SW24, it is determined that a setting instruction for the reference speed has been input, and the control characteristic for setting is selected. Subsequently, when the user operates the trigger SW 10 in this state, the motor 40 is driven and controlled in response to the operation amount of the trigger SW 10 according to the control characteristic for setting thus selected.

In addition, when the user stops the operation of the rotational speed setting SW24 while the motor 40 is driven and controlled as such, it is determined that the setting instruction for the reference speed has been newly input, and the rotational speed of the motor 40 at that time is stored in the nonvolatile memory 57 as the reference speed for the variable control characteristic. The stored reference speed is used as the highest rotation speed of the variable control characteristic for generating the variable control characteristic.

Therefore, the user can set the reference speed (highest rotation speed) of the variable control characteristic while actually rotating the motor 40 according to the control characteristic for setting by operating the trigger SW 10 and confirming the operation state of the power tool 1 at this time.

When the reference speed of the variable control characteristic is thus set, the user adjusts the rotational speed of the motor 40 to a desired rotational speed. During adjustment, the user needs to continue operating (pressing) the rotational speed setting SW 24.

However, only when the user is operating the rotational speed setting SW24, the motor 40 is driven and controlled according to the control characteristics for setting. When the user stops the operation of the rotational speed setting SW24, the rotational speed of the motor 40 at this time is stored as a reference speed (highest rotational speed). Therefore, the user can easily understand the setting operation of the reference speed.

The control characteristic for setting is set such that the rotational speed varies linearly in proportion to the operation amount of the trigger SW 10, with the maximum rotational speed at the time of full-speed driving of the motor 40 as the highest rotational speed for the set control characteristic and the smallest highest rotational speed among the control characteristics (high speed, middle speed, and low speed) of the normal mode as the lowest rotational speed for the set control characteristic. Further, the lowest rotational speed of the control characteristic for setting corresponds to a point at which the trigger SW 10 is operated by the user by a fixed amount of the minimum operation amount, not a point at which the operation amount of the trigger SW 10 is zero.

Therefore, the user can set an arbitrary rotational speed between the highest rotational speed of the low-speed control characteristic of the normal mode and the maximum rotational speed during full-speed driving of the motor 40 as the reference speed (highest rotational speed) of the variable control characteristic in the operating range from the minimum operation amount of the trigger SW 10 up to the maximum operation amount of the trigger SW 10.

Therefore, the user can easily and appropriately specify a desired rotational speed to be set as a reference speed (highest rotational speed) of the variable control characteristic. According to the present embodiment, the user's setting operation of the variable control characteristic is simplified. This may also improve the usability of the power tool 1.

Further, according to the electric power tool 1 of the present embodiment, the user switches the operation mode of the electric power tool 1 to the normal mode by operating the normal mode setting SW 22, and thereby can drive and control the motor 40 by one of the high speed fixed control characteristic, the medium speed fixed control characteristic, and the low speed fixed control characteristic.

Therefore, the electric power tool 1 of the present embodiment is convenient for a user who desires to change the control characteristic according to the application, although the setting operation of the variable control characteristic is frustrating.

In the present embodiment, the trigger SW 10 corresponds to an example of a first operation unit, the rotational speed setting SW24 corresponds to an example of a second operation unit, and the normal mode setting SW 22 corresponds to an example of a third operation unit.

In the present embodiment, the function as the storage unit is realized by the nonvolatile memory 57 and the rotational speed setting storage process executed by the control circuit 56 for storing the reference speed (highest rotational speed) of the variable control characteristic in the nonvolatile memory 57.

The function as a control unit is realized by a motor control process executed by the control circuit 56 for controlling the driving of the motor 40 at a rotational speed corresponding to a driving instruction (operation amount) from the trigger SW 10 in accordance with a variable control characteristic generated based on a reference speed (highest rotational speed).

[ first modification ]

In the above-described embodiment, it is described that the reference speed (highest rotational speed) of the variable control characteristic is set in the setting mode, and the rotational speed setting SW24 as the second operation unit is continuously operated until the desired rotational speed of the motor 40 to be set as the reference speed is obtained while updating the variable control characteristic.

It is further described that, based on the reference speed thus set, the timing for updating the variable control characteristic used in the control immediately follows the switching of the rotational speed setting SW24 from the "on" state to the "off" state and the reference speed is stored in the nonvolatile memory 57.

However, the setting operation of the reference speed may be performed after the user operates (turns on) the rotational speed setting SW24 to switch the control characteristic to the control characteristic for setting and then operates (turns on) the rotational speed setting SW24 again (in the on state).

Further, the reference speed-based update of the variable control characteristic may not be performed immediately after the reference speed is set and stored in the nonvolatile memory 57 (in other words, not performed during driving of the motor 40), but may be completed when the driving of the motor 40 is stopped after the reference speed is set.

In the first modification, a description will be made of a rotational speed setting storage process and a motor control process at the time of performing the setting of the reference speed (in other words, stored in the nonvolatile memory 57) and the updating of the variable control characteristic as described above.

As shown in fig. 10, in the rotational speed setting storage process of the first modification, if it is determined in S310 that the currently set operation mode is the set mode, the process moves to S322 to determine whether the rotational speed setting SW24 is pressed for a preset predetermined time (for example, several seconds) or longer.

Subsequently, when the rotational speed setting SW24 is pressed for a long time, it is determined that the setting instruction for the reference speed is input. The process proceeds to S330 to select a control characteristic for setting as a control characteristic for use in the current setting mode. The rotational speed setting storage process is terminated.

In S322, if it is determined that the rotational speed setting SW24 is not long-pressed, the process proceeds to S342 to determine whether the currently selected control characteristic is the control characteristic for setting. If the currently selected control characteristic is the control characteristic for setting, the process proceeds to S352. Otherwise, the rotational speed setting storage process is terminated.

In S352, it is determined whether the rotational speed setting SW24 is changed from the "off" state to the "on" state and the setting instruction for the reference speed is newly input.

In S352, when it is determined that the rotational speed setting SW24 has been changed from the "off" state to the "on" state, the process proceeds to S360 to store the current rotational speed command value of the motor 40 (in other words, the rotational speed of the motor 40) as the reference speed in the nonvolatile memory 57. The process proceeds to S362.

In S362, similar to S340 of the above embodiment, the variable control characteristic is selected as the control characteristic for use in the current setting mode. The process proceeds to S364.

In S364, the update flag is set so that: after the motor stop process of S440 in the motor control process is performed, the variable control characteristic is generated (updated) based on the reference speed stored in S360. The rotational speed setting storage process is terminated.

In S310, when it is determined that the operation mode is not the setting mode (in other words, the operation mode is the normal mode), the process proceeds to S380 to select the variable control characteristic as the control characteristic for use in the next setting mode and end the rotational speed setting storage process. The process of S380 is a process for preventing or inhibiting the motor 40 from being driven and controlled by the control characteristics for setting when the operation mode of the electric power tool 1 is switched from the normal mode to the set mode.

Now, as shown in fig. 11, the motor control process of the first modification is basically performed in a similar manner to the motor control process of the embodiment shown in fig. 8, but differs from the above-described embodiment in that the processes of S450 to S470 are performed after the motor stop process of S440 is performed.

That is, in the motor control process of the first modification, when the motor stop process is executed in S440, it is determined in S450 whether the update flag is set. If the update flag is not set, the motor control process is immediately terminated. If the update flag is set, the process proceeds to S460.

In S460, the variable control characteristic is generated (in other words, updated) and stored in the nonvolatile memory 57, and the reference speed stored in the nonvolatile memory 57 in S360 of the rotational speed setting storage process is taken as the highest rotational speed. In subsequent S470, the update flag is cleared, and the motor control process is terminated.

In the first modification, in setting the reference speed, it is necessary to operate (press) the rotational speed setting SW24 as the second operation unit twice, but it is only necessary to press the rotational speed setting SW24 long in the first operation.

However, when the SW24 is set by the rotational speed, the control characteristic of the motor 40 is switched from the variable control characteristic to the control characteristic for setting, and thus the reference speed can be set. Thus, in setting the reference speed, only the flip-flop SW 10 as the first operation unit needs to be operated.

Therefore, the user can concentrate on the adjustment of the rotational speed of the motor 40 for setting the reference speed. The setting operation of the reference speed can be performed more optimally.

In the first modification, after the reference speed is set and the driving of the motor 40 is stopped, the generation (updating) of the variable control characteristic is performed with the set reference speed as the highest rotation speed. Therefore, it is possible to suppress a sense of discomfort given to the user due to switching of the control characteristics during the operation of the motor 40.

When the variable control characteristic is updated after the driving of the motor 40 is stopped as such, it is not always necessary to turn off the trigger SW 10 and perform the motor stop process. For example, the motor stop process may be forcibly performed after the reference speed is set.

For this purpose, in S420 of fig. 11, in determining whether to drive the motor 40, it is only necessary to check the state of the update flag, and it is only necessary to proceed to the motor stop process of S440 if the update flag is set.

In this way, regardless of the state of the flip-flop SW 10, the motor stop process can be forcibly performed after the reference speed is set and stored in the nonvolatile memory 57, thereby updating the variable control characteristic.

[ second modification ]

In the above-described embodiment, it is described that, when the reference speed is set, the motor 40 is driven and controlled in accordance with the control characteristic for setting, and the rotational speed of the motor 40 is adjusted by the operation of the trigger SW 10 by the user.

However, in setting the reference speed, the control circuit 56 may be adapted to automatically change the rotational speed of the motor 40 according to a predetermined change characteristic (in other words, a change pattern) for setting, and the user may specify the reference speed by inputting a setting instruction when the motor 40 is at a desired rotational speed.

For this purpose, the rotational speed setting storage process may be performed as in the process shown in fig. 12, for example.

In the second modification, a rotational speed setting storage process in which the control circuit 56 is adapted to automatically change the rotational speed of the motor 40 so that the user can set the reference speed without operating the trigger SW 10 will be described.

As shown in fig. 12, in the rotational speed setting storage process of the second modification, when it is determined in S310 that the currently set operation mode is the setting mode, the process moves to S312 to determine whether or not the trigger SW 10 is in the on state.

When the trigger SW 10 is in the on state, the process proceeds to S320 to determine whether the rotational speed setting SW24 is in the on state. If the rotational speed setting SW24 is in the ON state, it is determined that the setting instruction for the reference speed has been input. The process proceeds to S332.

In S332, the rotational speed command value for use in driving and controlling the motor 40 is changed. Specifically, the rotational speed command value is set such that the rotational speed of the motor 40 is changed between the lowest rotational speed for setting and the highest rotational speed for setting within a predetermined period of time in accordance with the given variable control characteristic for setting.

The rotational speed of the motor 40 may be changed while being changed continuously from the lowest rotational speed for setting to the highest rotational speed for setting, continuously from the highest rotational speed for setting to the lowest rotational speed for setting, or both continuously from the lowest rotational speed for setting to the highest rotational speed for setting and continuously from the highest rotational speed for setting to the lowest rotational speed for setting.

As the minimum rotational speed for setting and the maximum rotational speed for setting, for example, the same rotational speeds as those of the control characteristics for setting of the above-described embodiment can be used.

In S332, when the rotational speed command value is set so that the rotational speed of the motor 40 is changed, the rotational speed setting storage process is immediately terminated.

The rotational speed command value set as such is used when the motor driving process (S430 shown in fig. 11) in the motor control process is executed.

Therefore, when the user is operating both the trigger SW 10 and the rotational speed setting SW24, the rotational speed of the motor 40 is changed between the lowest rotational speed for setting and the highest rotational speed for setting.

In S320, when it is determined that the rotational speed setting SW24 is not in the on state, the process proceeds to S350 to determine whether the state of the rotational speed setting SW24 has just changed from the on state to the off state, in other words, whether the setting instruction for the reference speed is input again.

In S350, when it is determined that the state of the rotational speed setting SW24 has just changed to the off state, the process proceeds to S365.

In S365, the current rotational speed command value of the motor 40 (in other words, the rotational speed of the motor 40) is stored in the nonvolatile memory 57 as the highest rotational speed of the variable control characteristic (i.e., the reference speed). The rotational speed setting storage process is terminated.

When it is determined in S310 that the operation mode is not the setting mode, when it is determined in S312 that the trigger SW 10 is not in the "on" state, or when it is determined in S350 that the rotation speed setting SW24 has not just changed to the "off" state, the rotation speed setting storage process is immediately terminated.

The reason why the rotational speed setting storage process is terminated after the process of S365 is executed is because it is not always necessary to store the variable control characteristic in the nonvolatile memory 57.

That is, when the motor 40 is driven during the motor driving, even in the case where the highest rotation speed of the control characteristic (fixed control characteristic or variable control characteristic) used at this time is read out from the nonvolatile memory 57, the motor 40 can be driven and controlled in accordance with the control characteristic. Specifically, if the highest rotational speed of the control characteristics is known at the time of driving the motor 40, the target rotational speed of the motor 40 can be calculated from the lowest rotational speed (i.e., zero) common to the respective control characteristics and the operation amount of the trigger SW 10. The driving of the motor 40 can be controlled by taking the target rotational speed as the rotational speed command value.

Therefore, in the second modification, when the highest rotational speed of the variable control characteristic (which is equal to the reference speed) is stored in the nonvolatile memory 57 in S365, the rotational speed setting storage process is terminated without executing the process for generating the variable control characteristic based on the highest rotational speed.

Therefore, in the second modification, the user is allowed to set the reference speed while checking the rotation of the motor 40 without adjusting the rotation speed of the motor 40 by operating the trigger SW 10. For this reason, the power tool 1 is convenient for a user who feels the operation of the trigger SW 10 troublesome.

[ third modification ]

In the second modification, when the operation mode of the electric power tool 1 is the setting mode, the user simultaneously operates both the rotational speed setting SW24 and the trigger SW 10 to set both the rotational speed setting SW24 and the trigger SW 10 in the on state. Subsequently, the motor 40 is driven and controlled so that the rotational speed is periodically and automatically changed.

In contrast, in the third modification, the rotational speed setting storage process is performed as in the process shown in fig. 13. When the operation mode of the electric power tool 1 is the setting mode, the rotation speed of the motor 40 is changed stepwise each time the user operates the rotation speed setting SW 24.

That is, in the rotational speed setting storage process of the present embodiment, if it is determined in S312 that the trigger SW 10 is in the "on" state, it is determined in S324 whether the rotational speed setting SW24 is operated and the state of the rotational speed setting SW24 has been changed from the "off" state to the "on" state.

When it is determined in S324 that the rotational speed setting SW24 is operated and the state of the rotational speed setting SW24 has been changed from the "off" state to the "on" state, the process moves to S332 to change the rotational speed instruction value, and the rotational speed setting storage process is ended.

In contrast, if it is not determined in S324 that the state of the rotational speed setting SW24 has been changed from the "off" state to the "on" state (i.e., the rotational speed setting SW24 is not operated again), the rotational speed setting storage process is immediately terminated.

In S312, when it is determined that the flip-flop SW 10 is not in the "on" state, the process proceeds to S355 to determine whether the state of the flip-flop SW 10 has just changed from the "on" state to the "off" state (in other words, whether the user has stopped the operation of the flip-flop SW 10).

If the state of the trigger SW 10 is just changed from the "on" state to the "off" state, the process proceeds to S365 as in the second modification to store the current rotation speed command value of the motor 40 as the highest rotation speed of the variable control characteristic in the volatile memory 57. The rotational speed setting storage process is terminated.

When it is determined in S310 that the operation mode is not the setting mode, or if it is determined in S355 that the state of the flip-flop SW 10 has not just changed from the "on" state to the "off" state, the rotational speed setting storage process is immediately terminated.

In the second modification, when the reference speed (highest rotation speed) of the variable control characteristic is set in the setting mode, the rotation speed setting SW24 is operated while the trigger SW 10 is operated to drive the motor 40. Subsequently, the rotational speed of the motor 40 is changed for each operation.

If the operation of the trigger SW 10 is stopped when the rotational speed of the motor 40 becomes a desired rotational speed, the rotational speed of the motor 40 at that time is stored in the nonvolatile memory 57 as a reference speed (highest rotational speed) of the variable control characteristic.

Thereafter, if the operation mode of the electric power tool 1 is the set mode, and when the trigger SW 10 is operated, the motor 40 is driven and controlled according to the variable control characteristic set based on the reference speed stored in the nonvolatile memory 57.

[ other modifications ]

Embodiments and modifications of the present disclosure have been described above. However, the electric working machine of the present disclosure is not intended to be limited to the above-described embodiments and modifications, but may take various different modes within a scope not departing from the gist of the present disclosure.

For example, the first operation unit in the above embodiment is the flip-flop SW. The first operation unit may be, for example, a variable resistor capable of inputting a drive instruction by a rotational operation, or a multi-stage switch or the like in which the position of a contact to be connected is changed according to a rotational position or a slide position. In other words, the first operation unit may be any device that: a drive command capable of specifying the rotational speed of the motor 40 can be input to the device.

The second operation unit and the third operation unit in the above-described embodiments are automatic reset type push button switches. However, each of these operation units may be any device that: in the device, an on/off state or an input signal level is changed according to an operation or an operation position of a user.

In the above embodiment, the reference speed (maximum rotational speed) is set by: the motor 40 is actually driven and the switch as the first operation unit is operated when the electric power tool 1 becomes the desired rotation state.

Conversely, the reference speed (highest rotation speed) may be set without driving the motor 40 by: the user operates a switch or a dial or the like serving as the second operation unit to directly input a parameter for selecting the reference speed.

The reference speed of the variable control characteristic does not necessarily have to be the highest rotation speed. The reference speed may be set, for example, to a rotational speed corresponding to a predetermined percentage of the total operation amount of the first operation unit, for example, a rotational speed at 80% of the total operation amount of the first operation unit.

In this case as well, by using the set rotational speed as the reference speed, the following control characteristics can be generated: the control characteristic can specify a rotation speed from a lowest rotation speed corresponding to a drive instruction (operation amount) from the first operation unit up to a highest rotation speed.

In the above-described embodiment, it is described that, of all the control characteristics such as the control characteristic for setting, the variable control characteristic, and the fixed control characteristic, the rotational speed from the lowest rotational speed to the highest rotational speed is linearly changed in proportion to the operation amount of the trigger SW 10.

However, each of these control characteristics may be nonlinear, for example, so that the change in the rotational speed is small in a region where the operation amount is small or the operation amount is large. Further, the control characteristic for setting in setting the reference speed may be linear as in the above-described embodiment, and the other control characteristics (i.e., the fixed control characteristic and the variable control characteristic) may be non-linear.

If the fixed control characteristic and the variable control characteristic are non-linear as such, each of these control characteristics may be set such that the rotational speed corresponding to the operation amount of the trigger SW 10 is reduced at a constant rate based on, for example, a high-speed fixed control characteristic in which the highest rotational speed is maximized.

That is, in the fixed control characteristic and the variable control characteristic as described above, similarly to the control characteristic shown in fig. 4, the rotational speed of the motor 40 is changed from the lowest rotational speed (i.e., zero) to the highest rotational speed set for each control characteristic in accordance with the operation amount of the trigger SW 10.

In the middle and low speed fixed control characteristics and the variable control characteristic, the rotational speed related to the operation amount of the trigger SW 10 is smaller than the rotational speed for the same operation amount in the high speed fixed control characteristic by the following ratio: the ratio is a ratio of the highest rotational speed in each of the control characteristics to the highest rotational speed in the high-speed fixed control characteristic.

In this case, the middle speed fixed control characteristic and the low speed fixed control characteristic and the variable control characteristic are nonlinear characteristics obtained by compressing the high speed fixed control characteristic in the axial direction of the rotational speed, as the linear control characteristic shown in fig. 4. Therefore, even in the case where each of the above-described control characteristics is set to have a non-linear configuration, the feeling of the rotational speed felt by the user from the motor 40 when increasing the rotational speed of the motor 40 to the highest rotational speed in each control characteristic and the feeling of the operation of the trigger SW 10 felt by the user can be matched. The user can operate the trigger SW 10 without discomfort.

In the above-described embodiment, when the motor 40 is driven and controlled according to the control characteristic or the variable control characteristic for setting, the fact is reported by blinking or lighting the LED of the setting mode display 34.

However, the report may be given by a display on a display panel constituted by an LCD (liquid crystal display) or the like, by an audio output, or by both the display on the LED or the display panel and the audio output, for example.

The electric power tool 1 receives a supply of electric power from the mounted battery pack 6 to operate. However, a power source such as the battery pack 6 may be provided separately from the power tool 1, and the power tool 1 may receive power supply from the power source using a power cord. Further, the power source may be an Alternating Current (AC) power source such as a commercial power source.

In the above embodiment, the motor 40 is a three-phase brushless motor. The motor 40 may be any motor capable of controlling the rotational speed. The motor 40 is not limited to a three-phase brushless motor, but may be another direct current motor, or may be an alternating current motor.

In the above-described embodiment, the electric working machine of the present disclosure is described as the electric power tool 1 provided with the striking mechanism driven by the motor (rechargeable impact driver) as an example. The electric working machine of the present disclosure is not intended to be limited to the above-described electric tool 1, but may be any electric working machine including a motor and a control unit for controlling a rotational speed of the motor in accordance with a drive instruction from an operation unit. Any such electric working machine can achieve the same effects as those of the above-described embodiment.

That is, the technique of the present disclosure may be applied to any electric working machine used in works such as handy-to-do, manufacturing, gardening, construction work, and the like. More specifically, the present disclosure may be applied to electric tools for masonry, electric tools for metal working, and electric tools for carpentry, and working machines for gardening, for example. More specifically, the present disclosure may be applied to various types of electric working machines, such as electric hammers, electric hammer drills, electric screwdrivers, electric wrenches, electric grinders, electric circular saws, electric reciprocating saws, electric wire saws, electric cutters, electric chain saws, electric planers, power nailers (including nailers), electric hedge trimmers, electric mowers, electric lawn trimmers, brush cutters, electric cleaners, electric blowers, electric sprayers, electric sprinklers, and electric cleaners, etc.

The functions of one component of the above-described embodiments may be implemented by a plurality of components, or one function having a single component may be implemented by a plurality of components. Further, a plurality of functions having a plurality of components may be implemented by a single component, or one function implemented by a plurality of components may be implemented by a single component. A part of the configuration of the above embodiment may also be omitted. At least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other of the above embodiments. All aspects included in the technical idea specified only by the language as set forth in the appended claims are embodiments of the present disclosure.

Claims (9)

1. An electric working machine comprising:

a motor;

a first operation unit configured to be operated by a user of the electric working machine and configured to output a drive instruction for the motor;

a control unit configured to drive the motor at a rotational speed corresponding to the drive instruction from the first operation unit;

a second operation unit configured to be operated by the user and configured to set a reference speed for driving the motor by the control unit; and

a storage unit configured to store the reference speed set via the second operation unit,

the control unit is configured to drive the motor at the rotational speed corresponding to the drive instruction from the first operation unit in accordance with a control characteristic set based on the reference speed stored in the storage unit,

wherein the second operation unit is configured to output a setting instruction for the reference speed,

wherein the control unit is configured to: when the setting instruction for the reference speed is input from the second operation unit, the motor is driven such that the rotational speed of the motor is changed between a lowest rotational speed for setting and a highest rotational speed for setting based on a preset variation characteristic for setting, and

wherein the storage unit is configured to: storing a current rotational speed of the motor being driven as the reference speed when the setting instruction for the reference speed is input from the second operation unit in a state where the control unit drives the motor based on the variation characteristic for setting.

2. The electric working machine according to claim 1,

wherein the control unit is configured to: the control unit is configured to set a control characteristic for use in drive control of the motor based on the reference speed when the reference speed is stored in the storage unit, and the control unit is configured to start drive control of the motor based on the control characteristic.

3. The electric working machine according to claim 1,

wherein the control unit is configured to: when the reference speed is stored in the storage unit and thereafter the output of the drive instruction from the first operation unit is stopped, a control characteristic set based on the reference speed stored in the storage unit is set as a control characteristic for use in implementing drive control of the motor.

4. The electric working machine according to claim 3,

wherein the control unit is configured to stop rotation of the motor when the reference speed is stored in the storage unit.

5. The electric working machine according to claim 1,

wherein the control unit is configured to: reporting that the motor is capable of being driven and controlled when the reference speed is stored in the storage unit and the motor is capable of being driven and controlled according to a control characteristic set based on the reference speed.

6. The electric working machine according to claim 1,

wherein the control unit is configured to be able to select any one mode from at least one regular mode and a setting mode as an operation mode of the control unit, and the control unit is configured to drive the motor in the selected operation mode, the at least one regular mode being a mode for drive-controlling the motor at a rotation speed corresponding to the drive instruction from the first operation unit according to at least one preset fixed control characteristic, and the setting mode being a mode for drive-controlling the motor at a rotation speed corresponding to the drive instruction from the first operation unit according to a variable control characteristic which is a control characteristic set based on the reference speed stored in the storage unit.

7. The electric working machine according to claim 6, further comprising a third operating unit configured to be operated by the user, and configured to switch the operating mode of the control unit to the at least one normal mode,

wherein the control unit is configured such that the operation mode is switched to the at least one normal mode by an operation of the third operation unit, and the operation mode is switched to the set mode by an operation of the second operation unit.

8. The electric working machine according to claim 7,

wherein the second operation unit and the third operation unit are disposed side by side, and a distance between the second operation unit and the third operation unit is longer than a length of at least one of the second operation unit and the third operation unit in an arrangement direction of the second operation unit and the third operation unit.

9. The electric working machine according to claim 7,

wherein a display unit configured to display a state of the electric working machine is provided between the second operation unit and the third operation unit.

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