JPH07106542B2 - NC cam grinder control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control device for controlling an NC cam grinder that grinds a cam, for example, when stopping and restarting during grinding, The present invention relates to an NC cam grinder control device capable of matching the relative positions of a member and a grindstone with a cam profile.

(Prior Art) Generally, there is, for example, a device called an NC cam grinder for automatically performing a grinding process in which a cam is ground by a grindstone. This NC cam grinder is shown in FIG. It is configured as shown in.

As shown in the figure, the member to be ground 1 is ground into a cam.
Are rotated by the C-axis motor 2.
Further, a grindstone 4 rotated by a grindstone motor 3 in the same direction as the rotating direction of the member to be ground 1 is attached to a slider 7, and the slider 7 is in a direction perpendicular to the central axis of rotation of the member to be ground 1. It is adapted to move toward and away from this central axis. The slider 7 is driven by the X-axis motor 6 and approaches the member 1 to be ground to bring the grindstone 4 into contact with the member 1 to be ground, thereby performing the grinding process.

Further, the C-axis motor 2 and the X-axis motor 6 are respectively controlled by the control device 8 shown in FIG.

As shown in the figure, the control device 8 receives a control signal for starting and terminating the grinding process from an external control device 10 that carries out overall control of the grinding process, and the C-axis motor 2 and the X-axis motor 6 respectively. A control unit 11 for controlling the is provided. The control unit 11 drives and controls the C-axis motor 2 and the X-axis motor 6 on the basis of the cam profile data preset in the data memory 17, and positions the workpiece 1 and the grindstone 4 on the basis of this data. By controlling, a cam having a desired cam profile is formed.

The data memory 17 is preset with cam profile data representing the cam profile of the cam to be formed as shown in FIG. 9 by the rotation angle of the member to be ground 1 and the position of the grindstone 4 with respect to this rotation angle. Then, as shown in the figure, the control unit 11 controls the C-axis position data and the X-axis position data for moving the C-axis motor 2 and the X-axis motor 6 according to the cam profile data based on the cam profile data. Is calculated, and the calculated position data is stored in the X-axis data memory 13 and the C-axis data memory 18 in correspondence with the machining elapsed time.

Then, the control unit 11 determines the X value stored in the X-axis data memory 13 based on the elapsed time output by the time counter 12.
The axis position data is read, the rotation amount of the X-axis motor 6 is calculated based on this X-axis position data, and this rotation amount is output to the X-axis servo amplifier 14. Then, the servo amplifier 14 supplies electric power according to the input rotation amount to the X-axis motor 6 and drives the X-axis motor 6 to drive the grindstone 4
Is moved to the position according to the X-axis position data.

At the same time, the X-axis pulse generator (hereinafter referred to as X-axis PG) 15 detects the amount of rotation of the X-axis motor and outputs it to the X-axis position counter 16. The X-axis position counter 16 converts this rotation amount into the current position data corresponding to the X-axis position data and outputs it to the control unit 11. Then, the control unit 11
The rotation amount output to the X-axis servo amplifier 14 is corrected according to the current position data. That is, the control unit 11 controls the X-axis PG
The X-axis motor 6 is feedback-controlled by 15 and the X-axis position counter 16, and the grindstone 4 is positioned at a position matching the cam profile with respect to the member 1 to be ground.

On the other hand, the control unit 11 also uses the C-axis data memory 18 and the C-axis servo amplifier 19 for the C-axis motor 2 so that the rotation angle of the workpiece 1 becomes the rotation angle according to the C-axis position data.
The axis motor 2 is driven and controlled, and at the same time, a C-axis pulse generator (hereinafter referred to as C-axis PG) 20 and a C-axis angle counter 21.
Thus, the C-axis motor 2 is feedback-controlled. These members are the same as the above-mentioned members for controlling the X-axis motor 6 and operate in the same manner, and thus the description thereof will be omitted.

As described above, the control unit 11 controls the X-axis motor 6 and the C-axis motor 2 based on the respective position data that is preset corresponding to the elapsed time output by the time counter 12.
By individually controlling and, and performing positioning control of the member to be ground 1 and the grindstone 4, the member to be ground 1 can be ground into a desired cam profile set in advance.

(Problems to be Solved by the Invention) In such a conventional control device, when it is necessary to stop the machining due to some cause during the grinding process, the control unit 11 performs relatively control. From a simple matter, the rotation of each motor is decelerated with uniform acceleration to stop machining,
Further, in the case of restarting as well, the rotation of each motor may be similarly accelerated to restart the machining.

However, when the rotation speeds of the respective motors are decelerated or increased at the time of stopping and restarting during the processing as described above, the rotation speeds of the respective motors in the steady state are different, and therefore, as shown in FIG. As shown, the time until the deceleration ends or the time until the acceleration ends is different, which causes the relative position between the workpiece and the grindstone to shift, resulting in a machining locus as shown in FIG. 11. Deviate from the cam profile. If the locus deviates inward from the cam profile, the cam profile will not be exactly as set even after restarting and remachining.
Since it has to be treated as a defective product, there have been problems such as a decrease in productivity.

The present invention has been made to solve such a conventional problem, and when the machine is stopped and restarted during processing, the relative positions of the member to be ground and the grindstone are aligned with the cam profile. It is an object of the present invention to provide an acceleration / deceleration control device for an NC cam grinder.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a cam motor for rotating a member to be ground on which a cam is formed, and a grindstone for grinding the member to be ground on a rotation center axis of the member to be ground. A grindstone moving motor that moves toward and away from each other is based on the rotation angle data of the member to be ground according to the cam profile in the steady state of the rotation speed of each motor and the movement position data of the grindstone corresponding to the rotation angle data. By controlling the rotation angle of the member to be ground and the moving position of the grindstone in the NC cam grinder control device for relative positioning control,
Control means for driving and controlling the cam motor and the grindstone moving motor based on the rotation angle data and the movement position data, a shift state detecting means for detecting a shift state in which the rotation speeds of the respective motors are shifted, and the shift state detecting means. When the shift state is detected, when the shift state is in an accelerating state, the timing at which the control means drives each motor is gradually advanced over time, and in the decelerating state, the timing is increased. Timing adjustment means for outputting to the control means a timing signal for gradually delaying with respect to the passage of time.

(Operation) The present invention configured as described above operates as follows.

The speed change state detecting means detects that the rotation speed of the cam motor and the whetstone moving motor is reduced when a signal for instructing an emergency stop is input to the control means from the outside during grinding, and the speed change state is detected. A deceleration state signal indicating that is output to the timing adjusting means.

The timing adjusting means, which receives the deceleration state signal, outputs to the control means a timing signal whose output interval is delayed with the passage of time.

Then, the control means drives and controls the cam motor and the grindstone moving motor based on the rotation angle data and the movement position data in synchronization with the timing signal, and decelerates the rotation speed of each motor.

As a result, when the cam motor is decelerating, a time margin for positioning the rotation angle of the member to be ground according to the rotation angle data is obtained according to the reduced rotation speed,
The member to be ground stops while being positioned at a rotation angle that matches the cam profile.

Similarly, the grindstone also has a time margin for positioning according to the movement position data, and the grindstone stops while being positioned at the movement position aligned with the cam profile.

As a result, during deceleration, the relative position between the member to be ground and the grindstone is aligned with this without deviating from the cam profile.

Further, after that, when the emergency stop is released and the signal instructing the restart is input to the control means, the gear shift state detection means detects that the gear motor is in the gear shift state in which the rotational speeds of the cam motor and the grindstone moving motor are accelerated, An acceleration state signal indicating an acceleration state is output to the timing adjusting means.

Then, the timing adjusting means outputs a timing signal in which the output interval is advanced according to the passage of time to the control means, and the control means synchronizes with the timing signal and based on the rotation angle data and the movement position data. The cam motor and the grindstone moving motor are drive-controlled, and the rotation speeds of the respective motors are accelerated.

As a result, the member to be ground and the grindstone are positioned in accordance with the rotation angle data and the movement position data according to the accelerated rotation speed, so that the relative position between the member to be ground and the grindstone is aligned with the cam profile in the steady state. Can be processed.

Therefore, during deceleration and acceleration, the relative position between the member to be ground and the grindstone does not deviate from the cam profile and maintains a state in which the relative position is maintained, so that the member to be ground does not become defective.

(Example) Below, the control apparatus of the NC cam grinder which concerns on this invention is demonstrated in detail based on drawing.

FIG. 1 is a schematic configuration diagram of a control device for an NC cam grinder according to the present invention, and FIG. 2 is a main flowchart showing the operation of the control device. FIG. 3 is a subroutine flowchart of the deceleration data output timing processing shown in FIG. 2, and FIG. 4 shows how the deceleration timing signal is output by the subroutine flowchart shown in FIG. . Further, FIG. 5 shows a subroutine flow chart of the acceleration data output timing processing shown in FIG. 2, and FIG. 6 shows how the acceleration timing signal is output by the subroutine flow chart shown in FIG. It is shown.

As shown in FIG. 1, in the control device for the NC cam grinder according to the present invention, a timing adjusting unit 30 as the timing adjusting means is connected to the control unit 11 and the time counter 12 in the control device described in the prior art. Has been done. The other members are the same as the members described in the related art, and thus the description thereof is omitted here.

The control unit 11 is adapted to input various signals related to the grinding operation output from the external control device 10, and among these signals, an emergency stop signal for stopping the operation due to some cause during the grinding operation. When input, C-axis motor 2
And the rotational speed of the X-axis motor 6 is decelerated with uniform acceleration.
At the same time, the control unit 11 outputs to the timing adjustment unit 30 a deceleration state signal indicating a deceleration state in which the rotation speed of each motor is decelerated.

Furthermore, the control unit 11 receives the emergency stop signal from the external control unit 10, and then the emergency stop is released, and when the restart signal output by the external control device is input when restarting, the rotation speed of each motor Is accelerated with constant acceleration. At the same time, the control unit 11 outputs to the timing adjustment unit 30 an acceleration state signal indicating that the rotation speed of each motor is increased and the rotation speed returns to the steady state. That is, the control unit 11 has a function as the control unit and a shift state detecting unit.

Then, when the deceleration state signal is input, the timing adjustment unit 30 outputs the deceleration timing signal to the time counter 12 in which the output interval is delayed with the passage of time. The time counter 12 outputs the number of times the deceleration timing signal is input to the control unit 11 as the elapsed time. That is, the elapsed time at which the interval at which the time changes according to the passage of time becomes longer is input to the control unit 11. This is because, when the rotation speed of each motor is reduced by the control unit 11, the time required for positioning (hereinafter referred to as the positioning time) becomes longer, so that the control unit 11 performs the next positioning in accordance with this positioning time. In order to delay the control timing, that is, the timing at which the control unit 11 outputs the rotation amount to each servo amplifier, so that each motor can be positioned according to the data in each data memory, to obtain a time margin. Is.

Further, when the acceleration state signal is input, the timing adjustment unit 30 outputs an acceleration timing signal to the time counter 12 in which the output interval is shortened as time passes. Then, the time counter 12 outputs the number of times of inputting the acceleration timing signal to the control unit 11 as the elapsed time similarly to the time of deceleration. That is, the control unit 11 is input with the elapsed time at which the interval at which the time changes according to the passage of time is advanced. This is because, contrary to the deceleration, when the rotation speed of each motor is increased by the control unit 11, the positioning time becomes shorter, and therefore the control unit 11 performs the next positioning control according to this positioning time. When to do it, that is, control unit
This is because 11 is to advance the timing of outputting the rotation amount to each servo amplifier and adjust the time so as to position each motor according to the data in each data memory.

Then, such a deceleration timing signal, or the control unit 11 that inputs the elapsed time according to the acceleration timing signal, based on the elapsed time, in the same manner as in the conventional case, each motor as the position data of each data memory according to the position data. Positioning control.

Therefore, the control unit 11 can perform positioning control in synchronization with the deceleration and acceleration timing signals output by the timing adjustment unit 30 during acceleration / deceleration, and thereby perform positioning control based on the cam profile data for each motor. The relative position between the member to be ground 1 and the grindstone 4 does not deviate from the cam profile.

The control device thus configured operates as follows based on the main flow chart shown in FIG.

First, the control unit 11 inputs the cam profile data stored in the data memory 17 as in the conventional case (step 1), calculates the C-axis position data and the X-axis position data based on the cam profile data, and calculates them. The respective position data are stored in the X-axis data memory 13 and the C-axis data memory 18 in correspondence with the elapsed time (step 2).

Next, the control unit 11 waits until an emergency stop signal or a restart signal is input from the external control device 10 (step 3,
Four).

When the emergency stop signal is input, the control unit 11 decelerates the rotation speeds of the respective motors by uniform acceleration and at the same time determines that they are in the deceleration state, and outputs a deceleration state signal to the timing adjustment unit 30.

The timing adjustment unit 30 which has received the deceleration state signal outputs the deceleration timing signal to the time counter 12 based on a flowchart described later (step 5).

On the other hand, when the restart signal is input, the control unit 11 accelerates the rotation speeds of the respective motors with uniform acceleration and at the same time determines that the motor is in the accelerated state, and outputs the acceleration state signal to the timing adjustment unit 30.

The timing adjuster 30 which has received the acceleration state signal outputs the acceleration timing signal to the time counter 12 based on a flowchart described later (step 6).

Then, the time counter 12 counts the input timing signal and outputs the counted number to the control unit 11 as the elapsed time. The control section 11 reads out the respective position data stored in the respective data memories based on the elapsed time, controls the respective motors in the conventional manner based on the respective position data, and controls the members to be ground 1 and The grindstone 4 is moved to a position according to each position data, the relative position between the grindstone 4 and the member 1 to be ground is matched with the cam profile, and the process returns to step 3 (step 7).

Next, the manner in which the timing adjustment unit 30 outputs the deceleration timing signal or the acceleration timing signal in steps 5 and 6 will be described with reference to FIGS.

FIG. 3 shows a flowchart for the timing adjustment unit 30 to output the deceleration timing signal in step 5, and FIG. 4 shows how the deceleration timing signal is output according to the elapsed time. It is shown.

By inputting the deceleration state signal from the control unit 11, the timing adjustment unit 30 outputs the deceleration timing signal based on the flowchart shown in FIG.

First, when the deceleration state signal is input, the timing adjustment unit 30 sets 0 to the constant A preset in the internal memory,
Substitute 10 for B and 10 for C as a deceleration constant (step 10). The deceleration constant can be set arbitrarily.

Then, the timing adjustment unit 30 determines whether or not to end the process based on the value of B (step 11), and then substitutes 10−10 = 0 for C (step 12).

Next, it is judged whether or not the value of C is 0 or less (step 13). Since the current value of C is 0, the timing adjusting section 30 outputs the deceleration timing signal to the time counter 12 once. Yes (step 14).

Then, the value obtained by adding the deceleration constant (10) to the current value of C,
That is, 0 + 10 = 10 is substituted into C (step 15), and the value obtained by adding 1 to the current value of A, that is, 0 + 1 = 1 is substituted into A (step 16).

It is judged whether or not the value of A is equal to or greater than the deceleration constant (10) (step 17). Since the current value of A is 1, step
Return to 11.

Then, since 0 is substituted into C again in step 12, the timing adjusting unit 30 repeats step 14 for each scan until A is incremented by 1 in step 16 to be 10.
At, the deceleration timing signal is output.

That is, as shown in FIG. 4, at the start of deceleration, the deceleration timing signal is output at a relatively short time interval for each scan.

When 10 is substituted for A in step 16, step 18
Then, 0 is assigned to A, a value obtained by subtracting 1 from the current value, that is, 10-1 = 9 is assigned to B, and the process returns to step 11.

Then, in step 12, 10-9 = 1 is substituted into C, and in step 13, since C is not 0 or less, the deceleration timing signal is not output and the process proceeds to step 16.

Then, 0 + 1 = 1 is substituted into A, and the process proceeds to step 12. Here, C becomes 1-9 = -8, and since C is 0 or less in step 13, the process proceeds to step 14 and the deceleration timing signal is output.

Further, in step 15, C becomes -8 + 10 = 2, and in step 16, A becomes 1 + 1 = 2. Further, C becomes 2-9 = -7 in step 12, and the deceleration timing signal is output in step 13.

Similarly, the deceleration timing signal is output for each scan until A becomes 10 again.

Then, in step 18, B is subtracted by 1 and becomes smaller than 0, and the deceleration timing signal is output as described above until it is determined in step 11 that the process is to be ended. Since the value becomes smaller and the number of times the process proceeds from step 13 to step 16 increases, the interval at which the timing adjustment unit 30 outputs the deceleration timing signal becomes wider.

As a result, as shown in FIG. 4, the deceleration timing signal is output to the time counter 12 at a relatively short time interval at the start of deceleration and at a relatively long time interval at the end of deceleration.

Next, the manner in which the timing adjusting section 30 outputs the acceleration timing signal will be described with reference to FIGS.

FIG. 5 shows the timing adjustment unit 30 in step 6 described above.
Shows a flowchart for outputting the acceleration timing signal, and FIG. 6 shows how the acceleration timing signal is output according to the elapsed time.

By inputting the acceleration state signal from the control unit 11, the timing adjustment unit 30 outputs the acceleration timing signal based on the flowchart shown in FIG.

First, when the acceleration adjustment signal is input, the timing adjustment unit 30 sets 0 to the constant A preset in the internal memory,
1 is assigned to B and 10 is assigned to C as an acceleration constant (step 20). Incidentally, this acceleration constant can be arbitrarily set like the deceleration constant.

Then, the timing adjustment unit 30 determines whether or not to end the process based on the value of B (step 21), and then substitutes 10-1 = 9 into C (step 22).

Next, it is determined whether or not the value of C is 0 or less (step 23). Since the current value of C is 9, the process proceeds to step 26.

Then, 0 + 1 = 1 is substituted for A, and in step 27, A is 1 and is not equal to or greater than the acceleration constant (10).
Return to 21.

Further, in step 22, 9-1 = 8 is assigned to C, and in step 23, C is 8. Therefore, the process proceeds to step 26 in the same manner as described above, and thereafter C is similarly subtracted by 1 in step 22. The acceleration timing signal is not output until it becomes zero.

Then, when C becomes 0 in step 22, the process proceeds to step 24, and the acceleration timing signal is output. further,
In step 25, 0 + 10 = 10 is substituted for C, and in step 26, A becomes 9 + 1 = 10.
The process proceeds from step 27 to step 28, 0 is substituted for A, 1 + 1 = 2 is substituted for B, and the process returns to step 21.

Then, in step 22, 10−2 = 8 is assigned to C, and thereafter, until A becomes 10 in step 27, C
Is subtracted by two, the process proceeds twice to step 24 during this period, and the acceleration timing signal is output.

Then, in step 28, B is incremented by 1 and becomes larger than the acceleration constant, and the acceleration timing signal is output as described above until the determination to end the process is made in step 21.
Becomes large, and the number of times of proceeding from step 23 to step 24 becomes large, and the time interval at which the acceleration timing signal is output becomes narrow.

As a result, as shown in FIG. 6, the acceleration timing signal is output to the time counter 12 at a relatively long time interval at the start of acceleration and at a relatively short time interval at the end of acceleration.

Therefore, in the deceleration state, the time counter 12
Based on the deceleration timing signal, the control unit 1 outputs an elapsed time in which the time interval at which the time changes according to the passage of time becomes longer, and the control unit 11 converts each motor into camp feel data according to the elapsed time. Based on the positioning control, the machining can be stopped while the relative positions of the member to be ground 1 and the grindstone 4 are aligned with the cam profile.

Further, in the acceleration state, the time counter 12 outputs to the control unit 11 the elapsed time in which the interval at which the time changes according to the elapsed time becomes short based on the acceleration timing signal, and the control unit
11, the position control of each motor is performed based on the cam profile based on the elapsed time, and the machining can be restarted while the relative positions of the member to be ground 1 and the grindstone 4 are aligned with the cam profile. it can.

In this embodiment, an emergency stop is performed during processing,
Although the case of restarting is illustrated, it is needless to say that the present invention is not limited to this and can be applied, for example, at the start of processing and at the end of processing.

Further, what detects the shift state of acceleration and deceleration is not limited to the control unit, and it goes without saying that a unit that detects the shift state may be provided separately from the control unit.

(Effects of the Invention) As is clear from the above description, the present invention has the following effects.

The speed change state detecting means detects that the speed is a speed change state in which the rotational speeds of the respective motors are changed, and when the speed change state is in the deceleration state, the deceleration state signal is output.
By outputting the acceleration state signal to the timing adjusting means, the timing adjusting means causes the timing adjusting means to gradually delay the timing at which the controlling means drives each motor in the decelerating state with respect to the passage of time. In the acceleration state, a timing signal that gradually advances the timing with respect to the passage of time is output to the control means, and the control means synchronizes with the timing signal to rotate the rotation angle data and the moving position. The cam motor and the grindstone moving motor are drive-controlled based on the data, and the rotation speeds of the respective motors are adjusted. As a result, the relative position between the member to be ground and the grindstone during deceleration and acceleration maintains a state in which the relative position does not deviate from the cam profile, so that the member to be ground does not become defective and the production is prevented. The property is improved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a control device for an NC cam grinding machine according to the present invention, FIG. 2 is a main flow chart showing the operation of the control device shown in FIG. 1, and FIG. 3 is a deceleration data output shown in FIG. Timing process subroutine flowchart, FIG. 4 is an explanatory diagram of deceleration timing signals output by the subroutine flowchart shown in FIG. 3, FIG. 5 is a subroutine flowchart of acceleration data output timing process shown in FIG. 2, and FIG. FIG. 5 is an explanatory diagram of the acceleration timing signal output by the subroutine flow chart shown in FIG. 5, and FIGS. 7 to 11 are explanatory diagrams of a conventional NC cam grinder control device. 1 ... Member to be ground, 2 ... C-axis motor (cam motor),
4 ... Grinding wheel, 6 ... X-axis motor (grinding wheel moving motor), 8
...... Control device, 11 ...... Control unit (control means, shift state detecting means), 12 ...... Time counter (timing adjusting means),
30: Timing adjustment section (timing adjustment means).

Claims (1)

[Claims] 1. A cam motor for rotating a member to be ground on which a cam is formed, and a grindstone moving motor for moving a grindstone for grinding the member to be ground toward and away from a rotation center axis of the member to be ground. The rotational speed of the grinding wheel is controlled in accordance with the rotation angle data of the member to be ground according to the cam profile in the steady state and the movement position data of the grindstone corresponding to the rotation angle data, whereby the rotation angle of the member to be ground and the movement of the grindstone are controlled. In the control device of the NC cam grinder that relatively controls the position relative to the position, control means for driving and controlling the cam motor and the grindstone moving motor based on the rotation angle data and the movement position data, and the rotation speed of each motor. When the shift state detecting means detects the shift state and the shift state is detected by the shift state detecting means, the shift state detecting means detects the shift state. In the speed state, the control means gradually advances the timing of driving each motor with the passage of time, and in the deceleration state, the timing signal for gradually delaying the timing with respect to the passage of time. NC cam grinding, characterized in that it has timing adjusting means for outputting to the control means, and does not deviate the relative position of the member to be ground and the grindstone from the cam profile when changing the rotational speed of each motor. Panel control device.