WO2024181313A1

WO2024181313A1 - Work machine

Info

Publication number: WO2024181313A1
Application number: PCT/JP2024/006592
Authority: WO
Inventors: 祥太鈴木
Original assignee: 工機ホールディングス株式会社
Priority date: 2023-02-28
Filing date: 2024-02-22
Publication date: 2024-09-06

Abstract

Provided is a work machine with improved operability. A plunger 126 and a driver blade 127 of a driving machine 100 which is the work machine are: moved by rotation of a transmitting mechanism 115 upward to the top dead center against a downward biasing force upon operation of a trigger 142 and a push lever 133 while positioned at a standby position; moved downward from the top dead center to the bottom dead center, by the biasing force, to hit a catch 125 when engagement with the transmitting mechanism 115 has been released at the top dead center; moved by rotation of the transmitting mechanism 115 upward from the bottom dead center to the standby position against the biasing force after reengagement with the transmitting mechanism 115 at the bottom dead center; and stopped at the standby position upon stoppage of the transmitting mechanism 115 in a state of being engaged with the transmitting mechanism 115 at the standby position. A control unit 116 can detect a load on an electric motor 114, stops the electric motor 114 on the basis of the load, and stops the plunger 126 and the driver blade 127 at the standby position.

Description

Work equipment

The present invention relates to a work machine.

Patent Document 1 discloses a work machine that stops the plunger that constitutes the striking part at a standby position after the striking part strikes a stopper. This work machine is equipped with a position detection switch that detects the position of the plunger. In this work machine, the plunger and counterweight move in conjunction with each other, and when the counterweight turns on the position detection switch, it is detected that the plunger has reached the standby position.

International Publication No. 2022/114119

However, if the stopping accuracy of the plunger at the standby position is low, there is a problem that the time from when the trigger and push lever are turned on and the motor starts to drive until the fastener is driven varies, resulting in reduced workability. For this reason, there has been a demand for improving the accuracy of stopping the plunger at the standby position in work machines.

The working machine according to the first aspect comprises a motor, an ejection unit that supports a stopper so that it can be ejected, an impact unit that is movable in a first direction and a second direction that is opposite to the first direction and that can strike the stopper supported by the ejection unit by moving in the first direction, a biasing unit that biases the impact unit in the first direction, an operating unit that is operated by an operator, a control unit that controls the drive of the motor, and a rotating unit that rotates by receiving the drive force of the motor. When the operation unit is operated while the striking unit is engaged with the rotating unit and positioned at the first position, the rotating unit rotates, moving from the first position to the second position in the second direction against the biasing force of the biasing unit, and disengaging from the rotating unit at the second position, moving from the second position to the third position in the first direction by the biasing force of the biasing unit to strike the stopper, and reengaging with the rotating unit at the third position, the rotating unit rotates, moving from the third position to the first position in the second direction against the biasing force of the biasing unit, and stopping the rotating unit in the first position while engaged with the rotating unit. The control unit is capable of detecting a load on the motor, and stops the motor based on the load to stop the striking unit at the first position.

The present invention provides a work machine with improved workability.

FIG. 2 is a front view showing the structure of the working machine according to the embodiment. 2 is a cross-sectional view showing a cross-sectional structure taken along line AA in FIG. 1. 4 is a cross-sectional view showing the state inside the working machine when the plunger is located at a standby position. FIG. 4 is a cross-sectional view showing the internal state of the working machine when the plunger is located at the top dead center. FIG. 4 is a cross-sectional view showing the internal state of the working machine when the plunger is located at the bottom dead center. FIG. 2 is a block diagram showing an outline of the main configuration of a control system for a work machine. FIG. 6 is a diagram showing a change in current of an electric motor accompanying the movement of a plunger. FIG. 11 is a flowchart illustrating a process flow during operation control. FIG. 13 is a diagram showing a change in a differential current value accompanying the movement of a plunger. 11 is a flowchart illustrating a process flow at the time of motion determination. 13 is a diagram showing a change in current detected when the plunger moves from a position different from the standby position. FIG. 11 is a block diagram showing an outline of the configuration of the main parts of a control unit of a work machine according to a second modified example. FIG. 11 is a flowchart illustrating a processing flow for the operation of a work machine according to a second modified example. FIG. 11 is a network configuration diagram showing the structure of a neural network of a work machine according to a second modified example.

The embodiment of the work machine will be described with reference to the drawings. In this embodiment, a driving machine will be used as an example of the work machine.

Figure 1 is a front view of the driving machine 100, and Figure 2 is a cross-sectional view of the driving machine 100 taken along line A-A in Figure 1. The driving machine 100 includes a housing section 111, an impact mechanism 112, a magazine 113, an electric motor 114, a transmission mechanism 115, a control section 116, a battery pack 117, and a counterweight section 118.

In the following explanation, the upper part of the paper in Figures 1 and 2 may be referred to as the top, and the lower part as the bottom. Furthermore, the left part of Figure 1 may be referred to as the right, and the right part as the left. Furthermore, the left part of Figure 2 may be referred to as the rear, and the right part as the front. Furthermore, the vertical direction toward the bottom may be referred to as the first direction, and the vertical direction toward the top may be referred to as the second direction.

<Housing section 111> The housing section 111 is an outer element of the driver 100. The housing section 111 has a body section 119, a handle section 120 connected to the body section 119, and a motor case 121 connected to the body section 119. An attachment section 122 is connected to the handle section 120 and the motor case 121.

The body 119 has a cylindrical shape that extends in the vertical direction. The body 119 contains the impact mechanism 112, the transmission mechanism 115, the counterweight 118, etc., which will be described later. An ejection section 123 with an ejection path 124 is provided at the tip of the body 119. That is, the ejection section 123 is fixed to the body 119. A fastener 125 contained in a magazine 113, which will be described later, is supplied to and supported in the ejection path 124 of this ejection section 123. When the fastener 125 supplied to the ejection path 124 is struck by a driver blade 127, which will be described later, it is ejected toward and driven into the workpiece W1. In other words, the ejection section 123 supports the fastener 125 so that it can be ejected.

A guide shaft 128, which is a plunger support shaft, is provided within the body 119. The center line E1 passes through the center of the guide shaft 128 as the rotation axis. The guide shaft 128 is supported by an adjustment dial 129 and an adjuster piece 134. The adjuster piece 134 is fixed to a bottom holder 130 attached to the body 119. The adjustment dial 129 is a member that adjusts the stopping position of the plunger 126, which is a movable part and will be described later, on the bottom dead center side in the vertical direction, and is provided at the upper end of the body 119.

An opening 139 (see Figures 3, 4, and 5) is formed on the front side of the body 119, which is used when replacing the driver blade 127 described below or when performing maintenance. The body 119 is provided with a cover portion 135 that covers this opening 139. The cover portion 135 is, for example, a resin member, and is attached so that the opening 139 can be opened and closed. In this embodiment, the cover portion 135 is removably fixed to the body 119 by a fastener such as a screw.

The handle portion 120 extends in the front-to-rear direction of the driving tool 100 at the rear of the body portion 119. A trigger 142 and a trigger switch 143 are provided below the handle portion 120. When the operator applies an operating force to the trigger 142, the push lever 133 provided at the bottom of the injection portion 123 descends, and when the push lever 133 abuts against the material to be driven W1, the trigger switch 143 turns on. When the operator releases the operating force applied to the trigger 142, the trigger switch 143 turns off.

The motor case 121 has a cylindrical shape that extends in the front-to-rear direction of the driver 100 at the rear of the body 119. The motor case 121 is a housing that houses the electric motor 114, the control unit 116, etc., which will be described later.

The mounting part 122 is disposed at the rear end of the handle part 120 and the motor case 121. The battery pack 117, which will be described later, is removably attached to the mounting part 122. In addition, a control part 116 that controls the operation of the driver 100 is provided within the mounting part 122.

<Magazine 113> The magazine 113 is disposed below the body 119 and the motor case 121. The magazine 113 is a storage section that stores a plurality of fasteners 125. The fasteners 125 are rod-shaped, for example, including nails. The magazine 113 has a feeder. The feeder sends the fasteners 125 stored in the magazine 113 to the ejection path 124.

<Impact mechanism 112> The impact mechanism 112 is provided on both the inside and outside of the body 119. The impact mechanism 112 has a plunger 126 arranged inside the body 119, a driver blade 127 attached to the plunger 126, and a coil spring 136 that can expand and contract in the vertical direction. The coil spring 136 abuts against the plunger 126 at its end in the first direction, which is the impact direction. Specifically, the coil spring 136 is a biasing part that applies a biasing force to the plunger 126 in the vertical downward direction (first direction).

The plunger 126 is made of, for example, metal or synthetic resin. The plunger 126 is arranged on the first direction (downward) side relative to the coil spring 136. The plunger 126 is arranged so that it can move in the first direction by receiving a biasing force from the coil spring 136. The plunger 126 is also arranged so that it can move in the second direction (upward) against the biasing force of the coil spring 136 by the transmission mechanism 115 described later.

The driver blade 127 is a member that drives in the stopper 125, and is made of, for example, metal. The driver blade 127 is attached to the plunger 126, and can move up and down along the injection path 124 of the injection part 123 described above. When the plunger 126 moves in the first direction, the driver blade 127 moves in the first direction together with the plunger 126, and strikes the stopper 125 supplied to the injection path 124. In other words, the plunger 126 and the driver blade 127 are movable in the first direction and in a second direction opposite to the first direction, and are an impact part that can strike the stopper 125 supported by the injection part 123 by moving in the first direction.

<Electric motor 114> The electric motor 114 has a rotor and a stator (not shown), and a motor shaft 146 is attached to the rotor. When the electric motor 114 is supplied with power from the battery pack 117, the rotor rotates, and the motor shaft 146 attached to the rotor rotates. The motor shaft 146 is connected to an input element 148 of a reduction gear (not shown) disposed in the motor case 121. This reduction gear further has multiple sets of planetary gear mechanisms and an output element 149. The driving force generated by the rotation of the electric motor 114, i.e., the rotational force generated by the rotation of the motor shaft 146, rotates the transmission mechanism 115 (described later) via the input element 148 and the output element 149.

<Transmission mechanism 115> The transmission mechanism 115 is disposed within the body 119 and is a rotating part that rotates upon receiving the rotational driving force of the electric motor 114. Specifically, the transmission mechanism 115 converts the rotational force of the motor shaft 146 into the operating force of the impact mechanism 112 and the operating force of the counterweight part 118. The transmission mechanism 115 biases the plunger 126 upward (second direction), which is the return direction of the coil spring 136, and biases the counterweight part 118 downward (first direction), which is the impact direction of the coil spring 136. As a result, the transmission mechanism 115 compresses the coil spring 136. The transmission mechanism 115 is composed of, for example, a first gear 150, a second gear 151, and a third gear 152. In addition, a weight bumper 137 against which the counterweight portion 118 can come into contact when released from the biasing force of the transmission mechanism 115, and a plunger bumper 138 against which the plunger 126 can come into contact are provided inside the body portion 119.

<Control unit 116> The control unit 116 is a microcomputer having an input/output interface, a calculation processing unit, and a memory unit. The control unit 116 controls the driving of the electric motor 114, as will be described in detail later.

<Battery pack 117> The battery pack 117 can be detachably attached to the mounting portion 122. The battery pack 117 is a DC power source, and the power of the battery pack 117 can be supplied to the electric motor 114. In other words, the battery pack 117 is a power source unit that supplies power to the electric motor, and the electric motor 114 is driven by the power supplied from the battery pack 117.

<Operation of the driving machine 100> The operation of the driving machine 100 will be described with reference to Figures 3, 4, and 5. Figures 3, 4, and 5 are cross-sectional views of the driving machine 100 similar to those in Figure 2, but show the driving machine 100 with the cover 135 removed. Figure 3 shows the state in which the plunger 126 is in the standby position (first position), Figure 4 shows the state in which the plunger 126 is in the top dead center (second position) above the standby position, and Figure 5 shows the state in which the plunger 126 is in the bottom dead center (third position) below the standby position and the top dead center. The standby position is a position in which the lower end of the driver blade 127 is on the second direction side (upper side) than the upper end of the stopper 125 supplied to the injection path 124. When the plunger 126 is in the standby position, the plunger 126 and the transmission mechanism 115 are engaged.

When in the state shown in FIG. 3, the operator grasps the handle portion 120 with his/her hand, presses the tip of the injection portion 123 against the workpiece W1, and applies an operating force to the trigger 142, causing the push lever 133 to descend. When the descended push lever 133 abuts against the workpiece W1, the trigger switch 143 turns on. In other words, the trigger 142 and the push lever 133 function as an operating unit that is operated by the operator. When the control unit 116 detects that the trigger switch 143 is on, it causes the battery pack 117 to supply power to the electric motor 114, causing the motor shaft 146 to rotate in the forward direction.

The rotational force of the motor shaft 146 is amplified by a reduction gear (not shown) and transmitted to the first gear 150. When the first gear 150 rotates, the second gear 151 also rotates, and the third gear 152 also rotates. This causes the plunger 126 and the driver blade 127 to move upward, i.e., in the second direction (rising). Meanwhile, the counterweight portion 118 moves downward, i.e., in the first direction (falling). When the counterweight portion 118 reaches the bottom dead center, the plunger 126 further rises, and then the plunger 126 reaches the top dead center (see FIG. 4). That is, when the plunger 126 and the driver blade 127 are engaged with the transmission mechanism 115 in the standby position and an operation is performed by the operator, the transmission mechanism 115 rotates, and the plunger 126 and the driver blade 127 move in the second direction against the biasing force of the coil spring 136 from the standby position to the top dead center. At this time, the coil spring 136 contracts and is in a state where maximum energy is stored.

Then, when the transmission mechanism 115 rotates and the plunger 126 is disengaged from the transmission mechanism 115, the coil spring 136 is released. This causes the plunger 126 to descend due to the biasing force of the coil spring 136. When the plunger 126 begins to descend, the counterweight portion 118 begins to rise due to the biasing force of the coil spring 136.

When the plunger 126 descends, the driver blade 127 also descends and strikes the stop 125 located in the injection path 124. As a result, the stop 125 is ejected from the ejection section 123 and driven into the workpiece W1. The plunger 126 stops descending when it reaches the plunger bumper 138, i.e., when it reaches the bottom dead center (see FIG. 5). That is, the plunger 126 and the driver blade 127 move in the first direction (downward) from the top dead center to the bottom dead center by the biasing force of the coil spring 136 as the plunger 126 and the transmission mechanism 115 are disengaged at the top dead center, striking the stop 125.

When the driver blade 127 finishes driving the fastener 125 and reaches the bottom dead center, the plunger 126 re-engages with the transmission mechanism 115. The transmission mechanism 115 is rotated by the motor shaft 146, which rotates forward together with the electric motor 114, which rotates by the power supplied from the battery pack 117. This rotation of the transmission mechanism 115 causes the plunger 126 and the driver blade 127 to rise against the biasing force of the coil spring 136. The control unit 116 stops the plunger 126 at a standby position on the second direction (upward) side of the bottom dead center (see FIG. 3). That is, the plunger 126 and the driver blade 127 re-engage with the transmission mechanism 115 at the bottom dead center, and then the transmission mechanism 115 rotates, causing the plunger 126 and the driver blade 127 to move in the second direction (upward) to the standby position against the biasing force of the coil spring 136.

The control unit 116 detects that the plunger 126 has reached the standby position based on the load on the electric motor 114, as described in detail below, and stops the operation of the electric motor 114. As a result, the plunger 126 and the driver blade 127 stop at the standby position as the rotation of the transmission mechanism 115 stops while they are engaged with the transmission mechanism 115 at the standby position.

<Control system configuration> Figure 6 is a block diagram showing an outline of the main configuration of the control system of the nail driver 100. As shown in Figure 6, in addition to the configuration described above, the nail driver 100 is equipped with a power switch circuit 200, a power supply voltage supply circuit 201, a voltage detection circuit 202, a current detection circuit 203, a trigger switch operation detection circuit 204, a push lever operation detection circuit 205, a nail remaining amount switch 207, a nail remaining amount switch operation detection circuit 208, a rotation position detection circuit 209, a rotation speed detection circuit 210, a control signal output circuit 211, an inverter circuit 212, a position detection switch 213, a position detection switch operation detection circuit 214, etc.

The power switch circuit 200 is a circuit that switches the connection between the battery pack 117 and the power supply voltage supply circuit 201 depending on the on/off state of the trigger switch 143 and instructions from the control unit 116. The power supply voltage supply circuit 201 is a constant voltage circuit that supplies the driving power of the battery pack 117 to each part of the driving machine 100 when the power switch circuit 200 is turned on. The voltage detection circuit 202 detects the voltage of the battery pack 117 and outputs a signal indicating the detected voltage to the control unit 116. The current detection circuit 203 detects the current value of the driving current supplied from the battery pack 117 to the electric motor 114 via the inverter circuit 212, and outputs a signal indicating the detected current value to the control unit 116.

When the trigger switch 143 is turned on, the trigger switch operation detection circuit 204 detects the operation of the trigger 142 by the operator and outputs a signal (operation signal) to the control unit 116. The push lever operation detection circuit 205 detects that the push lever 133 has come into contact with the workpiece W1 and outputs a signal to the control unit 116.

The nail remaining amount switch 207 is provided to engage with a feeding member such as a feeder at the end of the magazine 113 on the ejection section 123 side, and detects the remaining amount (e.g., 0 to 5 nails remaining) of fasteners 125 (connected nails) loaded in the magazine 113. The nail remaining amount switch operation detection circuit 208 detects the output of the nail remaining amount switch 207 and outputs a signal indicating the detection result to the control unit 116.

The rotational position detection circuit 209 is, for example, a Hall IC, which detects the position of the rotor and motor shaft 146 of the electric motor 114 in the rotational direction and outputs a signal indicating the rotational position to the control unit 116 and the rotation speed detection circuit 210. The rotation speed detection circuit 210 detects the rotation speed of the electric motor 114 based on the number of signals output from the rotational position detection circuit 209 counted within a unit time and outputs it to the control unit 116. The inverter circuit 212 is provided in the electric circuit between the stator of the electric motor 114 and the battery pack 117. The control signal output circuit 211 is controlled by the control unit 116 and outputs signals that turn on and off the switching elements of the inverter circuit 212 individually.

The position detection switch 213 is a switch operated by the counterweight portion 118, which moves in conjunction with the plunger 126. The position detection switch 213 is turned on when the counterweight portion 118, which has risen to the top dead center, comes into contact with it. The position detection switch operation detection circuit 214 detects that the position detection switch 213 has been turned on, and outputs a signal to the control unit 116.

<Processing of control unit 116> The control unit 116 detects the load on the electric motor 114, and controls the operation of the electric motor 114 based on the detected load (operation control), determines the operation of the impact mechanism 112 (operation process determination), and determines whether there is an abnormality in the operation of the impact mechanism 112 (abnormality determination).

<Operation Control> In operation control, when the control unit 116 determines based on the detected load that the plunger 126 has reached the standby position after the fastener 125 has been driven in, it stops the operation of the electric motor 114. In this embodiment, the control unit 116 detects the load by detecting the drive current of the electric motor 114, which is driven by power supplied by the battery pack 117. In other words, the control unit 116 stops the operation of the electric motor 114 based on the current value detected by the current detection circuit 203.

The control unit 116 detects the drive current of the electric motor 114, for example, every 100 μs, and converts the 10 current values detected every 100 μs into a 1 ms current value. Specifically, the control unit 116 adopts the maximum value of the total of 10 current values detected every 100 μs as the 1 ms current value. The adopted current value is stored in a storage medium such as a memory in the control unit 116.

Figure 7 is a diagram showing the current value detected when the plunger 126 moves from the standby position to the top dead center, the bottom dead center, and then back to the standby position. In Figure 7, the vertical axis represents the current value, and the horizontal axis represents time. Figure 7 shows the case where the trigger switch 143 is turned on at time 0 ms.

When the trigger switch 143 is turned on, the electric motor 114 starts to rotate due to the power supplied from the battery pack 117 as described above. At this time, the plunger 126 is stopped in the standby position (first position) and is biased downward (in the first direction) by the coil spring 136, so a large load is applied when the electric motor 114 starts to rotate, and the starting power (current) becomes large. As a result, the detected current value increases. At time t1 when the plunger 126 starts to rise and the influence of the starting power becomes low, the increase in the detected current value is suppressed, and the current value then remains at an approximately constant value.

When the plunger 126 reaches the top dead center (second position) and then disengages from the third gear 152 and the coil spring 136 is released, the plunger 126 starts to descend (time t2). When the plunger 126 descends, the load from the plunger 126 is no longer applied to the transmission mechanism 115, so the electric motor 114 rotates with a small load and the detected current value decreases rapidly. The current value decreases until the plunger 126 reaches the bottom dead center (third position) (time t5).

After time t5 when the plunger 126 reaches bottom dead center, as described above, it re-engages with the transmission mechanism 115 and rises again due to the rotation of the electric motor 114. This increases the load on the rotation of the electric motor 114, and as the plunger 126 rises, the detected current value also rises again. However, since the electric motor 114 is already rotating, no startup power is required. For this reason, there is no sudden increase in the detected current value, as there was from time 0 to time t1.

When the plunger 126 rises from the bottom dead center, the coil spring 136 is compressed and the downward biasing force increases, so the load required to rotate the electric motor 114 gradually increases. That is, the detected current value gradually increases. Then, when it is determined at time t7 that the plunger 126 has reached the vicinity of the standby position, the control unit 116 stops the rotation of the electric motor 114 after a predetermined standby time has elapsed. In other words, the standby time can be considered to be the delay time between when the current value becomes equal to or greater than the first threshold value th1 described below and when the control unit 116 stops the electric motor 114.

The control unit 116 uses the current value detected by the current detection circuit 203 to raise the plunger 126 that has reached the bottom dead center to the standby position (pre-winding) and stop it. Specifically, the control unit 116 uses a first threshold value th1 and a second threshold value th2 to compare the detected current value. The first threshold value th1 is used to determine whether the plunger 126 has reached the vicinity of the standby position due to pre-winding. Specifically, the control unit 116 determines that the plunger 126 has reached the vicinity of the standby position due to pre-winding when the state in which the detected current value is equal to or greater than the first threshold value th1 has elapsed for a first determination time (e.g., 5 ms) or more. That is, the control unit 116 detects that the current value has become equal to or greater than the first threshold value th1 at time t6, and determines that the plunger 126 has reached the vicinity of the standby position when the state in which the current value is equal to or greater than the first threshold value th1 continues until time t7 when the first determination time has elapsed.

The second threshold th2 is used to determine whether or not preliminary winding is possible after the plunger 126, which has reached the top dead center, descends toward the bottom dead center. Specifically, the control unit 116 determines that preliminary winding of the plunger 126 is possible when the state in which the detected current value is equal to or less than the second threshold th2 has elapsed for a second determination time (e.g., 10 ms) or more. That is, the control unit 116 detects that the current value has become equal to or less than the second threshold th2 at time t3, and determines that preliminary winding is possible when the current value remains equal to or less than the second threshold th2 until time t5, when the second determination time has elapsed. Note that the first threshold th1 and the second threshold th2 may be the same value or different values.

Also, when the voltage value of the battery pack 117 decreases, the number of rotations of the electric motor 114 decreases and the inertia decreases, so the distance that the plunger 126 can rise during the standby time becomes shorter. That is, the preliminary winding ends without the plunger 126 reaching the standby position. In order to suppress the occurrence of such a malfunction, the control unit 116 changes the standby time when stopping the rotation of the electric motor 114 (i.e., the delay time after the current value becomes equal to or greater than the first threshold value th1) according to the voltage of the battery pack 117. In this case, the control unit 116 lengthens the standby time when the voltage value of the battery pack 117 detected by the voltage detection circuit 202 becomes smaller than a preset value. For example, the control unit 116 detects the voltage value of the battery pack 117 before the plunger 126 starts to rise (start) from the standby position, that is, before the electric motor 114 starts to rotate. The control unit 116 lengthens the standby time by 1 ms every time the detected voltage value becomes 0.4 V lower than the preset value. Additionally, the control unit 116 may linearly increase the standby time in response to a decrease in the detected voltage value.

The process steps performed by the control unit 116 in the operation control will be described with reference to the flowchart shown in FIG. 8. The process steps shown in FIG. 8 are performed by the control unit 116 reading a program stored in the storage unit and executing the program.

In step S10, the control unit 116 determines whether the current value detected by the current detection circuit 203 is equal to or less than the second threshold value th2. If the current value is equal to or less than the second threshold value th2, the control unit 116 makes a positive determination and the process proceeds to step S11. If the current value is greater than the second threshold value th2, the control unit 116 makes a negative determination and the process of step S10 is repeated.

In step S11, the control unit 116 determines whether or not the second determination time of 10 ms has elapsed. If the second determination time has elapsed, the control unit 116 makes a positive determination. The control unit 116 then determines that pre-winding of the plunger 126 is possible. Processing then proceeds to step S12. If the second determination time has not elapsed, the control unit 116 makes a negative determination, and processing returns to step S10.

In step S12, the control unit 116 obtains the current value, which is the load of the electric motor 114 performing the preliminary winding, from the current detection circuit 203, and determines whether the current value is equal to or greater than the first threshold value th1. If the current value is equal to or greater than the first threshold value th1, the control unit 116 makes a positive determination and the process proceeds to step S13. If the current value is less than the first threshold value th1, the control unit 116 makes a negative determination and the process of step S12 is repeated.

In step S13, the control unit 116 determines whether or not the first determination time of 5 ms has elapsed. If the first determination time has elapsed, the control unit 116 makes a positive determination, and the process proceeds to step S14. If the first determination time has not elapsed, the control unit 116 makes a negative determination, and the process returns to step S12.

In step S14, it is determined whether the waiting time has elapsed. If the waiting time has elapsed, the control unit 116 makes a positive determination, and the process proceeds to step S15. If the waiting time has not elapsed, the control unit 116 makes a negative determination, and the process of step S14 is repeated. In step S15, the control unit 116 stops the electric motor 114 and ends the process.

<Operation Step Determination> In operation step determination, the control unit 116 determines the operation step of the plunger 126 and the driver blade 127 based on the amount of change in the detected load. In this case, the control unit 116 also detects the load by detecting the drive current of the electric motor 114, which is driven by the power supplied by the battery pack 117. In other words, the control unit 116 determines the operation step of the plunger 126 and the driver blade 127 based on the amount of change in the current value detected by the current detection circuit 203.

As described above, the control unit 116 detects the drive current of the electric motor 114, for example, every 100 μs, and converts the 10 current values detected every 100 μs into a current value for 1 ms. The control unit 116 then calculates the difference (differential current value) between a certain current value and the current value converted from that current value 10 ms earlier, a predetermined time interval, as the amount of change in the current value. The control unit 116 determines the operating process of the plunger 126 and the driver blade 127 based on the change in the differential current value obtained at each of the above-mentioned time intervals.

Figure 9 is a diagram showing the change in the differential current value when the plunger 126 moves from the standby position to the top dead center, the bottom dead center, and then back to the standby position. In Figure 9, the vertical axis represents the differential current value, and the horizontal axis represents time. Figure 9 shows the case where the trigger switch 143 is turned on at time 0 ms.

As described above, the starting power (current) is large immediately after the electric motor 114 starts to rotate. Therefore, at time t10, the differential current value increases sharply. Then, when the plunger 126 starts to rise, the influence of the starting power (current) decreases, and the differential current value decreases. Therefore, at time t10, the differential current value becomes a maximum value (up-peak). At time t10 when this up-peak is detected, the control unit 116 determines that the plunger 126 has started to rise (start) as an operating process.

When the plunger 126 starts, the load associated with the rotation of the electric motor 114 decreases, so the rise of the plunger 126 accelerates and the differential current value also decreases. The differential current value decreases until time t12 when the plunger 126 reaches top dead center. At time t11 between time t10 and time t12, the differential current value becomes 0 A. When the control unit 116 detects that the differential current value becomes 0 A at time t11 and then decreases further (zero crossing), it determines that the operation process is an accelerating rise of the plunger 126.

After the plunger 126 reaches the top dead center at time t12, the plunger 126 disengages from the transmission mechanism 115 and starts to descend, and the differential current value starts to increase. Therefore, at time t12, the differential current value becomes a minimum value (down peak). At time t12 when this down peak is detected, the control unit 116 determines that the start of the plunger 126 is complete as an operating process.

When the control unit 116 detects that the differential current value decreases for a predetermined time (e.g., 5 ms) or more after the acceleration increase is determined, then increases once, and then increases again for a predetermined time (e.g., 5 ms) or more, the control unit 116 determines that the striking process in which the driver blade 127 strikes the stopper 125 is the operation process. In FIG. 9, the differential current value decreases from time t11 to time t12, increases from time t12 to time t13, and decreases from time t13 to time t14. Therefore, the control unit 116 determines that the driver blade 127 strikes the stopper 125 and the stopper 125 is ejected. In other words, the control unit 116 determines that the striking process is performed when the differential current value decreases for a predetermined time, detects a down peak at time t12, and then increases again, decreases for a predetermined time, and detects a peak at time t14.

After time t14, the differential current value starts to increase again when the plunger 126 starts to re-engage with the transmission mechanism 115. The differential current value that starts to increase exceeds 0 A (zero cross) at time t15. Therefore, when the zero cross is detected at time t15, the control unit 116 determines that the preliminary winding of the plunger 126 has started as an operating process. After that, when the plunger 126 reaches the standby position due to the preliminary winding, the control unit 116 stops the rotation of the electric motor 114 as described above (time t16).

The processes performed by the control unit 116 in the operation determination will be described with reference to the flowchart shown in FIG. 10. Each process shown in FIG. 10 is performed by the control unit 116 reading a program stored in the storage unit and executing the program.

In step S20, the control unit 116 detects a steep increase in the calculated differential current value. In step S21, the control unit 116 determines whether or not an up-peak has occurred in the change in the differential current value. If an up-peak has occurred in the change in the differential current value, the control unit 116 makes a positive determination. At this time, the control unit 116 determines the start of the plunger 126 as an operating step. The process then proceeds to step S22. If an up-peak has not occurred, the control unit 116 makes a negative determination, and the process of step S21 is repeated.

In step S22, the control unit 116 determines whether or not a zero cross has occurred in the change in the calculated differential current value. If a zero cross has occurred in the change in the differential current value, the control unit 116 makes a positive determination. At this time, the control unit 116 determines that the plunger 126 is accelerating upward as an operating step. The process then proceeds to step S23. If a zero cross has not occurred in the change in the differential current value, the control unit 116 makes a negative determination, and the process of step S22 is repeated.

In step S23, the control unit 116 determines whether a down-peak has occurred in the change in the calculated differential current value. If a down-peak has occurred in the change in the differential current value, the control unit 116 makes a positive determination. At this time, the control unit 116 determines that the start of the plunger 126 has been completed as an operation step. Thereafter, the process proceeds to step S24. If a down-peak has not occurred in the change in the differential current value, the control unit 116 makes a negative determination, and the process of step S23 is repeated.

In step S24, the control unit 116 determines whether the change in the calculated differential current value increases once and then decreases, i.e., whether a peak occurs again due to an increase or decrease in the change in the differential current value after a down-peak. If a peak occurs in the change in the differential current value by increasing after a down-peak and then decreasing again, the control unit 116 makes a positive determination. At this time, the control unit 116 determines that the operation process is the striking process in which the driver blade 127 strikes the stopper 125. The process then proceeds to step S25. If a peak does not occur in the change in the differential current value after the down-peak, the control unit 116 makes a negative determination, and the process of step S24 is repeated.

In step S25, the control unit 116 determines whether or not a zero cross has occurred in the change in the calculated differential current value. If a zero cross has occurred in the change in the differential current value, the control unit 116 makes a positive determination. At this time, the control unit 116 determines that the preliminary winding of the plunger 126 has started as an operating process. Thereafter, the process proceeds to step S26. If a zero cross has not occurred in the change in the differential current value, the control unit 116 makes a negative determination, and the process of step S25 is repeated. In step S26, the control unit 116 determines that the preliminary winding of the plunger 126 is in progress as an operating process based on the calculated differential current value, and ends the process when the plunger 126 reaches the standby position.

<Abnormality determination> In abnormality determination, the control unit 116 determines whether or not an abnormality has occurred in the operation process of the impact mechanism 112 based on the detected load or change in load. Specifically, the control unit 116 determines whether or not an abnormality has occurred based on the change in the current value detected during operation control or the differential current value detected during operation determination. Specifically, the control unit 116 determines that an abnormality has occurred in the movement of the impact mechanism 112 when the current value becomes equal to or less than the second threshold value th2 after a predetermined response error timing. In other words, the control unit 116 determines whether or not an abnormality has occurred in the movement of the plunger 126 and the driver blade 127 based on the time from when the operator performs an operation until the detected current value becomes equal to or less than the second threshold value th2. In addition, the control unit 116 determines that an abnormality has occurred in the movement of the impact mechanism 112 when the current value becomes equal to or more than the first threshold value th1 after a predetermined timeout error timing. In other words, the control unit 116 determines whether there is an abnormality in the movement of the plunger 126 and the driver blade 127 based on the time from when the operator performs the operation until the detected current value becomes equal to or greater than the first threshold value th1.

Alternatively, the control unit 116 determines that an abnormality has occurred in the drive of the impact mechanism 112 when a waveform different from the waveform showing the change in the differential current value shown in FIG. 9 is detected. In other words, the control unit 116 determines whether the movement of the plunger 126 and the driver blade 127 has been performed normally based on the change in the differential current value, which is the amount of change in current at each predetermined time interval. For example, the control unit 116 determines that an abnormality has occurred in the movement of the plunger 126 and the driver blade 127 when the above-mentioned impact process is not determined until the detected current value becomes equal to or greater than the first threshold value th1. That is, the control unit 116 determines that an abnormality has occurred in the movement of the plunger 126 and the driver blade 127 when the impact process is not determined between the time the operator performs the operation and the time the electric motor 114 is stopped based on the load and the plunger 126 and the driver blade 127 are stopped at the standby position. The control unit 116 performs the abnormality determination after the current value becomes equal to or greater than the first threshold value th1 and the plunger 126 is stopped.

Figures 11 (A) to (D) are diagrams showing the waveforms of the current values detected when the plunger 126, which is not in the standby position, moves, with the vertical axis representing the differential current value and the horizontal axis representing time. Note that in Figures 11 (A) to (D), 100 ms is the timing for determining a response error, and 300 ms is the timing for determining a timeout error.

Figure 11 (A) shows the waveform of the current value when the plunger 126, which was located at the bottom dead center, starts due to a factor such as a voltage drop in the battery pack 117. In this case, the plunger 126 starts starting from the bottom dead center, so it starts descending without reaching the top dead center. As shown in the figure, the detected current value is equal to or less than the second threshold value th2 at time t20 before the response error. After that, when the current value becomes equal to or greater than the first threshold value th1, the plunger 126 stops at the standby position. At this time, if the impact process has not been determined based on the change in the differential current value, the control unit 116 determines that an abnormality has occurred. In this case, the control unit 116 warns the operator that an abnormality has occurred using, for example, a warning unit such as a warning lamp (not shown). Then, the control unit 116 prevents the driving machine 100 from operating, such as by not driving the electric motor 114.

Figure 11 (B) shows the waveform of the current value when the plunger 126, which was located above the bottom dead center, starts to start. In this case, as in Figure 11 (A), the plunger 126 starts to descend without reaching the top dead center. As shown in the figure, the detected current value becomes equal to or less than the second threshold value th2 at time t21 before the response error. After that, when the current value becomes equal to or more than the first threshold value th1, the plunger 126 stops at the standby position. However, since the position at which the plunger 126 starts to start is higher than in Figure 11 (A), the time required for the plunger 126 to stop at the standby position is shorter than in the case shown in Figure 11 (A). At this time, the control unit 116 determines that an abnormality has occurred if the impact process has not been determined based on the change in the differential current value. In this case, the control unit 116 warns the operator that an abnormality has occurred, for example, by turning on a warning lamp (not shown). The control unit 116 then prevents the driver 100 from operating, for example by not driving the electric motor 114.

Figure 11 (C) shows the waveform of the current value when the plunger 126 starts to move, which is located above the position where the plunger 126 stopped in Figure 11 (B) and below the standby position. Also, the control unit 116 is assumed to determine the impact process based on the change in the differential current value. In this case, the plunger 126 starts to move down after reaching the top dead center, since it starts to move up from near the standby position.

As shown in FIG. 11(C), the detected current value becomes equal to or less than the second threshold value th2 at time t22 after the response error. The detected current value becomes equal to or greater than the first threshold value th1 at time t23 after the timeout error. In this way, if the current value does not become equal to or less than the second threshold value th2 before the timing of the response error, or if the current value becomes equal to or greater than the first threshold value th1 after the timeout error, the control unit 116 determines that an abnormality has occurred and stops driving the electric motor 114.

Figure 11 (D) shows the waveform of the current value when the plunger 126, which was located near the top dead center, begins to start. It is also assumed that the control unit 116 determines the impact process based on the change in the differential current value. In this case, the plunger 126 starts from near the standby position, so it begins to descend after reaching the top dead center. As shown in the figure, the detected current value is equal to or less than the second threshold value th2 at time t24 before the response error. Then, when the current value becomes equal to or greater than the first threshold value th1, the plunger 126 stops. In this case, the control unit 116 determines that there is no abnormality in the plunger 126.

The embodiment described above provides at least one of the following effects:

(1) The control unit 116 can detect the load of the electric motor 114. The control unit 116 stops the electric motor 114 based on the detected load, thereby stopping the plunger 126 and the driver blade 127, which move in the vertical direction by the driving force of the electric motor 114 and the biasing force of the coil spring 136, at the standby position. This makes it possible to determine that the plunger 126 has reached the standby position based on the load of the electric motor 114, so that the plunger 126 and the driver blade 127 can be stopped at the standby position with high accuracy. Therefore, the variation in the time from when the trigger 142 and the push lever 133 are turned on and the electric motor 114 starts driving to when the fastener 125 is driven is reduced, which contributes to improving the workability of the worker using the driving machine 100. In addition, when used together with a position detection switch such as the position detection switch 213, it is possible to further improve the accuracy of stopping the plunger 126 and the driver blade 127 at the standby position. Furthermore, even if the position detection switch 213 is broken, it is possible to stop the plunger 126 and the driver blade 127 in the standby position, so the position detection switch 213 may be eliminated, which reduces the number of parts and makes it possible to make the driver 100 lighter and smaller.

(2) The control unit 116 detects the drive current of the electric motor 114 as the load of the electric motor 114. This makes it possible to detect the load of the electric motor 114 with a simple configuration.

(3) When the detected current value becomes equal to or greater than the first threshold value th1, the control unit 116 stops the electric motor 114. This makes it possible to detect that the electric motor 114 has reached the vicinity of the standby position, thereby enabling the plunger 126 to be stopped at the standby position with high accuracy.

(4) When the detected current value becomes equal to or less than the second threshold value th2 and then equal to or greater than the first threshold value th1, the control unit 116 stops the electric motor 114. This makes it possible to determine that the plunger 126 has risen and reached the standby position after the stopper 125 has been ejected. As a result, erroneous determination of the position of the plunger 126 is suppressed, and the accuracy of position detection when stopping the plunger at the standby position can be improved.

(5) The control unit 116 stops the electric motor 114 after a predetermined delay time has elapsed since the detected current value became equal to or greater than the first threshold value th1, i.e., after the first discrimination time has elapsed and the standby time has elapsed. This makes it possible to raise the plunger 126, which has risen close to the standby position, to the standby position and stop it there.

(6) The control unit 116 changes the standby time based on the voltage value of the battery pack 117. This makes it possible to extend the time during which the plunger 126 can rise even when the rotation speed of the electric motor 114 decreases and the inertia becomes low due to a decrease in the remaining battery charge of the battery pack 117. As a result, it is possible to prevent the occurrence of a malfunction in which the preliminary winding ends before the plunger 126 reaches the standby position.

(7) The control unit 116 determines whether or not there is an abnormality in the movement of the plunger 126 and the driver blade 127 based on the time from when the operator performs an operation until the detected current value becomes equal to or less than the second threshold value th2. This allows the presence or absence of an abnormality to be determined based on the time at which a characteristic point in the change in the current value appears, making it possible to determine whether or not the stopper 125 has been ejected using a simple configuration.

(8) The control unit 116 determines whether or not there is an abnormality in the movement of the plunger 126 and the driver blade 127 based on the time from when the operator performs an operation until the detected current value becomes equal to or greater than the first threshold value th1. This makes it possible to determine whether or not there is an abnormality based on whether or not the plunger 126 reaches the standby position by the time set as the timeout error.

(9) The control unit 116 determines whether the movement of the plunger 126 and the driver blade 127 is normal or not based on the amount of change in the load at each predetermined time interval, i.e., the differential current value which is the amount of change in the current. This makes it possible to determine whether there is an abnormality in the movement of the plunger 126 and the driver blade 127 with a simple configuration.

(10) The control unit 116 determines the operation process of the plunger 126 and the driver blade 127 based on the amount of change in the load at each predetermined time interval, i.e., the differential current value, which is the amount of change in the current. This makes it possible to determine what operation the plunger 126 and the driver blade 127 have performed with a simple configuration.

(11) When the change in the differential current value decreases for a predetermined time, then increases, and then decreases again for a predetermined time, the control unit 116 can determine that the striking process in which the driver blade 127 strikes the stopper 125 is an operation process. When the striking process is not performed between the time the operator performs an operation and the time the electric motor 114 is stopped and the plunger 126 and the driver blade 127 are stopped at the standby position, the control unit 116 determines that there is an abnormality in the movement of the plunger 126 and the driver blade 127. This makes it possible to detect the current value of the electric motor 114 with a simple configuration, and to determine that there is an abnormality in the movement of the plunger 126 and the driver blade 127 based on the detected current value and the differential current value.

(12) When the change in the differential current value becomes minimal, then increases and decreases again, the control unit 116 determines that the driver blade 127 has struck the stopper 125 and the stopper 125 has been ejected. This makes it possible to determine, with a simple configuration, whether or not the stopper 125 has been ejected based on the change in the load on the electric motor 114.

The above-described embodiment can be modified as follows:

<Modifications> (1) The control unit 116 is not limited to detecting the drive current as the load of the electric motor 114, and may detect the rotation speed of the electric motor 114. In this case, the control unit 116 detects the rotation speed of the electric motor 114 based on a signal output from the rotation speed detection circuit 210. Then, based on the increase or decrease in the detected rotation speed, the control unit 116 determines whether or not the plunger 126 has been pre-wound after the stopper 125 is ejected and has reached the standby position. Specifically, the control unit 116 stores in advance the rotation speed of the electric motor 114 when the standby position is reached by pre-wounding as a threshold value, and stops the rotation of the electric motor 114 when the detected rotation speed becomes smaller than this threshold value.

(2) The first threshold th1 or the second threshold th2 may be a variable value. For example, the control unit 116 may change the value of the first threshold th1 according to the remaining battery charge of the battery pack 117. In this case, the control unit 116 detects the remaining battery charge of the battery pack 117 based on the voltage value of the battery pack 117 detected by the voltage detection circuit 202 when the plunger 126 is started. Alternatively, the control unit 116 may calculate (detect) the remaining battery charge of the battery pack 117 based on the current value detected when the plunger 126 is started. When the detected remaining battery charge value becomes smaller than a preset value, the control unit 116 increases the value of the first threshold th1. At this time, the control unit 116 may increase the value of the first threshold th1 linearly or nonlinearly (e.g., stepwise) according to the decrease in the detected voltage value.

Alternatively, the control unit 116 may change the first threshold th1 or the second threshold th2 according to the number of times the fasteners 125 have been ejected (the number of driving operations). In this case, the control unit 116 can calculate the number of fasteners 125 used, i.e., the number of driving operations, based on the signal output from the nail remaining amount switch operation detection circuit 208, and increase the value of the first threshold th1 according to an increase in the number of driving operations.

Alternatively, the control unit 116 may vary the first threshold value th1 or the second threshold value th2 based on the deterioration of the coil spring 136. In this case, the control unit 116 determines the degree of deterioration of the coil spring 136 based on the value of the starting current of the electric motor 114. For example, if the coil spring 136 has become soft due to deterioration, the control unit 116 may reduce the first threshold value th1. Also, if the coil spring 136 has become hard due to deterioration, the control unit 116 may increase the first threshold value th1.

Alternatively, if the driving tool 100 is equipped with a gas spring instead of the coil spring 136, the control unit 116 may vary the first threshold value th1 or the second threshold value th2 based on the change in air pressure in the accumulator chamber. In this case, too, the control unit 116 determines the change in air pressure in the accumulator chamber based on the value of the starting current of the electric motor 114. For example, if compressed air is leaking from the accumulator chamber and the air pressure is decreasing, the control unit 116 may decrease the first threshold value th1. Also, if the air pressure in the accumulator chamber is increasing, such as when the outside temperature is high, the control unit 116 may increase the first threshold value th1.

(3) The control unit 116 is not limited to determining whether the plunger 126 has reached the standby position based on the detected current value and the first threshold value th1. For example, the control unit 116 may learn the waveform of the detected current value as teacher data and use the waveform of the detected current value to determine whether the plunger 126 has reached the standby position based on the learning result.

(4) The control unit 116 may perform control to gradually reduce the ascending speed of the plunger 126 when stopping the plunger 126 at the standby position. In this case, multiple thresholds smaller than the first threshold th1 are set in advance, and the control unit 116 may reduce the number of rotations of the electric motor 114 by a predetermined rate each time the detected current value exceeds these multiple thresholds.

(5) The control unit 116 may perform control to stop the plunger 126 at the bottom dead center. In this case, for example, a threshold value corresponding to the current value at time t5 shown in FIG. 7 is set, and when the control unit 116 determines that the detected current value has reached this threshold value, it may stop driving the electric motor 114.

<Variation 2> The driving machine 100, which is a work machine of variation 2, uses artificial intelligence (AI) to determine when to stop the electric motor 114 in order to stop the plunger 126 at the standby position. For example, the current value is machine-learned by the artificial intelligence in advance, and the time to stop the electric motor 114 is determined based on the data obtained by the machine learning (learning model). As an example, variation 2 uses a neural network (hereinafter also referred to as "NN") to perform control by the control unit 316.

Figure 12 is a block diagram showing the main components of the control unit 316 of the driving machine 100 according to the second modified example. The control unit 316 of the second modified example replaces the control unit 116 of the embodiment described above. The trained model 301 is an example of a trained model, and is data used when determining the timing to stop the electric motor 114 based on changes in the current value. The NN calculation unit 302 is an example of a calculation unit, and is a calculation circuit that controls the current supply pattern to the stator according to the timing to stop the electric motor 114 determined based on the trained model 301.

Figure 13 is a flow chart showing the start and stop of the electric motor 114 in the driving machine 100 according to the second modified example. In step S321, the control unit 316 performs an NN calculation using the trained model 301 based on the changes in the current value data and the rotor position data stored in the data storage unit 303, and in step S322, it determines (estimates) the time to stop the electric motor 114 based on the results of the NN calculation. In step S323, the electric motor 114 is stopped at the determined time to stop the electric motor 114, and the process ends.

Figure 14 is a network configuration diagram showing the structure of the neural network of the driving machine 100 according to the second modification. The NN calculation unit 302 determines the stop time of the electric motor 114 by using an NN with a predetermined number of sampled current values as input data 310 and the stop time of the electric motor 114 as output data 313. Information regarding the stop time of the electric motor 114 is input to the motor discharge stop control unit 305 (see Figure 12), which sends a signal to the motor control unit 306 (see Figure 12) based on the information regarding the stop time of the electric motor 114. The motor control unit 306 controls the control signal output circuit 211 based on the signal sent from the motor discharge stop control unit 305, and stops the electric motor 114 at the appropriate time.

In the estimation control using NN shown in FIG. 14, as an example, multiple input data 310 are narrowed down by machine learning to primary narrowed down data 311, and further narrowed down to secondary narrowed down data 312, and output data 313 of the stop timing of the electric motor 114 is calculated. The multiple input data 310 are narrowed down by machine learning based on the influence of factors, the degree of relationship, and the like. In other words, as the narrowing down progresses to the primary and secondary stages, data with less influence are removed by reducing the coefficients, and finally the output data 313 of the motor power supply stop position is calculated. Note that the number of times the multiple input data 310 are narrowed down is not limited to two, and may be three or more times.

The driving machine 100 according to this second modification can accurately determine the time to stop the electric motor 114 even when the waveform of the current value is complex and it is difficult to detect the inflection point, so that the driving machine 100 can be provided at low cost. The input data 310 of the NN calculation unit 302 may also include other information such as the voltage value of the battery pack 117, which allows the time to stop the electric motor 114 to be determined even more accurately.

Various embodiments and modifications have been described above, but the present invention is not limited to these. Other embodiments that are conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention.

100...driver, 111...housing section, 112...impact mechanism, 113...magazine, 114...electric motor, 115...transmission mechanism, 116, 316...control section, 117...battery pack, 118...counterweight section, 119...body section, 120...handle section, 121...motor case, 122...mounting section, 123...ejection section, 124...ejection path, 125...stopper, 126...plunger, 127...driver blade, 136...coil spring, 137...weight bumper, 138...plunger bumper, 142...trigger, 143...trigger switch, 146...motor shaft, 148...input element, 149...output element, 150...first gear, 151...second gear, 152...second 3 gears, 200...power switch circuit, 201...power supply voltage supply circuit, 202...voltage detection circuit, 203...current detection circuit, 204...trigger switch operation detection circuit, 205...push lever operation detection circuit, 207...nail remaining amount switch, 208...nail remaining amount switch operation detection circuit, 209...rotation position detection circuit, 210...rotation speed detection circuit, 211...control signal output circuit, 212...inverter circuit, 213...position detection switch, 214...position detection switch operation detection circuit, 301...trained model, 302...NN calculation unit, 303...data storage unit, 310...input data, 311...first refined data, 312...second refined data, 313...output data

Claims

A motor;
an ejection section that supports the fastener so as to be ejectable;
a striking portion that is movable in a first direction and a second direction opposite to the first direction and that strikes the stopper supported by the ejection portion by moving in the first direction;
a biasing portion that biases the striking portion in the first direction;
An operation unit operated by an operator;
A control unit that controls the driving of the motor;
a rotating unit that rotates by receiving a driving force of the motor,
The striking part is
When the operating portion is operated in a state where the operating portion is engaged with the rotating portion and positioned at a first position,
When the rotating portion rotates, the rotating portion moves in the second direction against the biasing force of the biasing portion from the first position to the second position,
When the engagement with the rotating portion is released at the second position, the biasing force of the biasing portion moves the stopper from the second position to a third position in the first direction to strike the stopper,
the rotating portion rotates after re-engaging with the rotating portion at the third position, thereby moving in the second direction from the third position to the first position against the biasing force of the biasing portion;
the rotating portion stops in a state of being engaged with the rotating portion at the first position, thereby stopping at the first position;
The control unit is capable of detecting a load on the motor, and stops the motor based on the load, thereby stopping the impact unit at the first position.
The working machine according to claim 1,
The load is an electric current.
In the work machine according to claim 2,
The control unit stops the motor when the detected current value becomes equal to or greater than a first threshold value.
In the working machine according to claim 3,
The control unit stops the motor when the detected current value becomes equal to or less than a second threshold and then becomes equal to or greater than the first threshold.
In the working machine according to claim 3 or 4,
The control unit stops the motor after a predetermined delay time has elapsed since the detected current value became equal to or greater than the first threshold value.
In the work machine according to claim 5,
The control unit is capable of detecting a voltage of a power supply unit that supplies power to the motor, and changes the delay time based on the detected voltage of the power supply unit.
In the working machine according to claim 4,
The control unit determines whether or not there is an abnormality in the movement of the impact part based on the time from when an operation is performed on the operating part to when the detected current value becomes equal to or less than the second threshold value.
In the working machine according to claim 3,
The control unit determines whether or not there is an abnormality in the movement of the impact part based on the time from when an operation is performed on the operating part to when the detected current value becomes equal to or greater than the first threshold value.
The working machine according to claim 1,
The control unit determines whether or not the movement of the striking unit has been performed normally based on an amount of change in the load at each predetermined time interval.
The working machine according to claim 1,
The control unit determines an operation step of the impact unit based on an amount of change in the load at each predetermined time interval.
The work machine according to claim 10,
The control unit is
As the operation process, a striking process in which the striking part strikes the fastener can be determined, and in the striking process, if an amount of change in the load at each predetermined time interval decreases for a predetermined period of time, increases, and then decreases again for a predetermined period of time, it is determined that the striking part strikes the fastener,
A work machine in which the control unit determines that there is an abnormality in the movement of the impact part if it is not determined that the impact process has been performed between the time an operation is performed on the operating unit and the time the motor is stopped based on the load and the impact part is stopped at the first position.
In the work machine according to claim 7,
When the amount of change in the current becomes minimal, then increases and decreases again, the control unit determines that the striking unit has struck the fastener and the fastener has been ejected.