JPS5926401Y2 - Origin return device for moving objects - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an origin return device for a movable body that corrects deviation of the movable body from its origin position.

Conventionally, a movable body using a pulse motor or the like as a drive source, such as a grindstone head of a digital feed grinding machine, detects the origin position using an origin detection device such as a limit switch, and uses the origin position for fine grinding of the whetstone head, etc. This was used as a reference position for the rough grinding feed origin, etc.

However, when the control power supply of the grinding machine is turned on or off, the pulse motors mentioned above may be rotated with different excitation phases, and therefore, when the work is finished, the grinding head is at the origin. If the power supply is cut off while the grindstone is in the position, the grindstone head will shift from its home position when the next work starts.
In addition, the origin position may shift due to inertia.

If the grinding wheel head deviates from the origin position in this way, it becomes difficult to return the grinding wheel head to the respective grinding feed origin points, etc. mentioned above, and the grinding accuracy of the workpiece W decreases. The generator was used to return the grindstone head to its original position.

However, the above method has a drawback that the operation of returning the grindstone to the origin is complicated because it is unclear in which direction the grindstone has deviated from the origin position.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art by providing an origin return device for a movable body that can easily correct the deviation of the movable body from its original position.

The first embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, reference numeral 1 denotes a grindstone head that is reciprocatably mounted on the bed of a grinding machine (not shown), on which a grinding wheel 2 is rotatably mounted and supported by a chuck or the like (not shown). The workpiece W that has been ground is ground.

Reference numeral 3 denotes a feed screw of the grindstone 1 rotated by the pulse motor PM, and is screwed into a threaded portion 4 attached to the grindstone 1.

Therefore, the grindstone 1 is moved forward (moves the grindstone 1 in the direction of the workpiece W) by the forward rotation of the pulse motor PM, and is moved backward (moves the grindstone 1 in the opposite direction to the workpiece W) by the reverse rotation of the pulse motor PM. .

5 is a rotating shaft rotatably attached to the bed, and is interlocked with the feed screw 3 via a gear 6.6 with a tooth ratio of 1:1.

Reference numeral 7 denotes a slitting disk attached to the shaft 5, which is rotated as the shaft 5 rotates, that is, as the grindstone head 1 moves.

Next, as shown in FIG. 2, the disk 7 has a semicircular slit BS with a small radius and a semicircular slit FS with a large radius relative to the rotation center of the disk 70. Furthermore, a small hole O5 is formed through the disk 7 at a position different from the center distance of the two slots BS and FS.

Reference numeral E denotes a light source attached to the bed across the table 7 together with photoelectric switches PTB, PTF, and PTO, and is lit by a power source (not shown) using a light emitting diode, a lamp, or the like.

The photoelectric switches PTB, PTF, and PTO are composed of a light receiving section such as a transistor, an amplifier, an output section, etc., and the output thereof is "1" when receiving light and "O" when cutting off light.

Furthermore, the charging switch PTO detects the origin position of the grinding wheel head 1 (the state shown in FIG. 1), and when the grinding wheel head 1 is at the origin position and the disc 7 is in the state shown in FIG. It is attached to the bed so that it can receive light via O3.

Further, the photoelectric switch PTF detects that the grinding wheel head 1 is retreated from the origin position, and when the grinding wheel head 1 is retreated and the disk 7 is rotated from the state shown in FIG. 2 in the direction opposite to the arrow shown in the figure. It is attached to the bed so that it can receive light through a slit FS provided in the disk 7.

The photoelectric switch PTB is installed on the disk 7 to detect when the grinding wheel head 1 is displaced from the origin position in the forward direction, and when the disk 7 is rotated in the direction of the arrow in FIG. It is attached to the bed so that the light is received via the BS.

Therefore, only one of the photoelectric switches PTO, PTF, and PTB is activated no matter what rotational position the disk 7 is in.

8 is a detector near the origin of the whetstone 1, which is attached to the bed and is operated by a dog 9 provided on the whetstone 1.
The origin vicinity detector 8 is connected to the grindstone head 1 as shown in FIG.
is output as 1 while the disk 7 moves back and forth by half a rotation from the origin position.

Next, the electric circuit of this embodiment will be explained.
is a control circuit into which information such as a commanded feed rate and a commanded feed amount of the grindstone head 1 is read and stored, and a voltage corresponding to the commanded speed is sent to the pulse oscillator 11 in response to a start command.

12.13.14.15 is an AND circuit to which a drive pulse train corresponding to the command speed from the pulse oscillator 11 is input; A forward command is input, and the output side of the AND circuit 12 and the output side of the AND circuit 13 are connected to the normal rotation terminal F of the pulse motor drive circuit 17 via the OR circuit 16.

The pulse train input to the drive circuit 17 is input to a counter or the like (not shown) in the control circuit 10, and the amount of movement of the grindstone head 1 is detected.

The output of the pulse motor drive circuit 17 is input to the pulse motor PM.

In addition, a backward command for the grindstone 1 sent from the control circuit 10 when the counter etc. counts up, that is, the amount of movement of the grindstone 1 reaches a set value, is input to the AND circuit 15. The output side of the AND circuit 14 and the output side of the AND circuit 14 are connected to the reverse terminal B of the pulse motor drive circuit 17 via an OR circuit 18.

Next, 19 is a flip-flop circuit, and a voltage (
+V), and is reset by the output of the near-origin detector 8 and the output of the charging switch PTO via the AND circuit 20.

Also, it is input to the flip-flop AND circuits 13 and 14, and the control circuit 1
0 is input as a pulse oscillation command for returning the grindstone head 1 to its origin.

Therefore, the control circuit 10 sends a voltage according to the origin return pulse oscillation command to the pulse oscillator 11, and the pulse oscillator 11 sends out a pulse train for the origin return of the grindstone head 1.

Further, the output of the AND circuit 20 is inputted to the control circuit 10 as a reset signal, and the contents of the counter are set to zero.
At the same time, the retreat command for the grindstone head 1 is canceled.

Further, the output of the origin vicinity detector 8 is output from the AND circuit 13.
．． 14, the output of the photoelectric switch PTB is connected to the AND circuit 1
4, the outputs of the charging switch PTF are respectively input to the AND circuit 13.

Subsequently, the functions and effects of the above embodiment will be explained.

At the start of work, etc., the push button switch PB for returning to the origin of the grindstone 1 is pressed prior to the grinding work of the workpiece W. In this case, the origin proximity detector 8 is activated by the dog 9 of the grindstone 1.
1" is output, and the grinding wheel head 1 is retreated from the home position due to a change in the excitation phase of the pulse motor PM due to the opening/closing operation of the control power supply, etc., the wheel head 1 is moved back from the state shown in FIG. 2. It is rotated in the opposite direction of the arrow, and the disk 7
Due to the slit FS, only the photoelectric switch PTF is “°1”
The output of the AND circuit 20 is set to "0".

Therefore, when the push button switch PB is turned on, the flip-flop path 13. 14 to send out one output, and a pulse oscillation command for returning the grindstone head 1 to the origin is issued to the control circuit 10.

Next, based on the return command, the control circuit 10 sends a home return speed signal of the grinding wheel head 1 to the pulse oscillator 11, and the pulse oscillator 11 sends a return pulse train according to the signal to the AND circuits 12 to 15. Send.

However, the control circuit 10 does not send forward or backward commands for the final grinding wheel head 1, and the charging switch PTB is not turned on.
AND circuits 12, 14 by "0" output.

15 is also set to 0°, the return pulse train is input to the normal rotation terminal F of the pulse motor drive circuit 17 via the AND circuit 13 and the OR circuit 16.

Therefore, by the forward rotation of the pulse motor PM, the grindstone head 1 is moved forward and begins to return to the original position.

Next, when the grinding wheel head 1 reaches the home position, the grinding wheel 7 is returned to the state shown in Fig. 2, and the charging switches PTO, PTF,
The output of PTB is small hole OS and slit FS.

“1 99 44 0 99 “0” by BS respectively
Therefore, the sending of the reset pulse train to the pulse motor drive circuit 17 via the AND circuit 13 is stopped.

Further, the output of the AND circuit 20 to which the "1" output of the near-origin detector 8 and the photoelectric switch PTO is input resets the flip-flop circuit 19 to cancel the origin return command, and in the control circuit 10, the The content of the counter that was counting the amount of movement of is set to zero, and the sending of the return speed signal to the pulse oscillator 11 is stopped.

As a result, the grindstone head 1 is returned to its original position, and the grinding operation is thereafter started in response to a start command.

Next, the origin proximity detector 8 is activated by the dog 9 of the grinding wheel head 1.
To explain the case where the grinding wheel head 1 is shifted forward in the state where 1" is output, in this case, the disk 7 has been rotated in the direction of the arrow from the state shown in FIG. 2, and the photoelectric switches PTO, P
Since TF and PTB output uon% "0" and "1", respectively, the output of the AND circuit 20 is "°0°".

Next, when the pushbutton switch PB is turned on, the flip-flop circuit 19 is set, and the pulse oscillator 1
1, a return pulse train is sent to AND circuits 12-15.

However, in this case as well, the AND circuit 12.15 is “0”.
Since the output of the AND circuit 13 is also set to "O" by the "0" output of the charging switch PTF, the above return pulse train is sent to the reverse terminal of the pulse motor drive circuit 17 via the AND circuit 14 and the OR circuit 18. It is input to B.

Therefore, the grindstone head 1 is moved backward by the reverse rotation of the pulse motor PM and begins to return to the original position.

Next, when the grinding wheel head 1 reaches the home position, the second
By returning to the state shown in the figure, the photoelectric switches PTO, PTF, P
Since TB is outputted as "1", "0", and "O", the sending of the return pulse train via the AND circuit 14 is stopped.
Similar to the above, the grindstone head 1 is returned to the origin.

Next, even if the push button switch PB for return to origin is pressed while the grindstone head 1 is at the origin position, the AND circuit 20
Since the output stops the sending of the home return speed signal from the control circuit 10, the grindstone head 1 is not moved from the home position.

Therefore, when the grinding wheel head 1 is returned to the home position as described above, the control circuit 10 activates the AND circuit 12 by the start command.
A forward command for the grinding wheel head 1 is sent to the pulse oscillator 11.
A command feed speed signal is sent to the

This causes the pulse oscillator 11 to send out a drive pulse train according to the command speed to the AND circuits 12 to 15.
Since the flip-flop is "0" and the retraction command for the grinding wheel head 1 has not been sent, the drive pulse train is input to the forward rotation terminal F of the pulse motor drive circuit 17 via the AND circuit 12 and the OR circuit 16. Ru.

Therefore, when the grinding wheel head 1 is advanced at the set speed and the grinding of the workpiece W is completed and the feed amount of the grinding wheel head 1 reaches the set value, a counter in the control circuit 10 is counted up.

As the counter counts up, the forward command for the grinding wheel head 1 is canceled, and the control circuit 10 sends a backward command for the grinding wheel head 1 to the AND circuit 15, so that the forward rotation terminal F of the pulse motor drive circuit 17 is driven. The sending of the pulse train is stopped and the forward movement of the grindstone head 1 is stopped, and the driving pulse train is manually inputted to the reverse rotation terminal B of the pulse motor drive circuit 17 via the AND circuit 15 and the OR circuit 18.
The grindstone head 1 is retracted.

Next, when the grinding wheel head 1 is retreated and reaches the home position, "1" is output from both the home position proximity detector 8 and the photoelectric switch PTO, and the control circuit 10 outputs "1" from the AND circuit 20.
The backward command and the command feed speed signal are stopped, and the contents of the counter are also set to zero.

Therefore, the grinding wheel head 1 is stopped at the home position, and the above-mentioned operation is repeated. However, even if the grinding wheel head 1 deviates from the home position due to inertia, it is possible to easily move the whetstone head 1 to the home position by simply operating the home return push button switch PB. It can be returned to position.

The present invention includes a detection device that detects the origin position of a movable body and a deviation from the origin position, and a control device that returns the movable body to the origin position in response to a detection signal from the detection device in response to a home return command for the movable body. By providing this, there is an effect that the movable body can be easily and accurately returned to the origin position which is the reference for its operation, and therefore the work performed by the movable body can be performed with high precision.

In addition, since the present invention is configured to check the origin signal by the AND condition of the signals of both the origin detection device and the origin vicinity detector, it is possible to check the origin signal from among the signals output every time the disk rotates The correct origin signal can be easily identified.

[Brief explanation of the drawing]

FIG. 1 is an embodiment diagram including an electric circuit according to a first embodiment of the present invention;
FIG. 2 is an explanatory diagram showing an embodiment of a detection device for detecting the origin position of a moving body and a deviation from the origin position in the present invention. 1... Grinding wheel head, 7... Slit tooth disk, 8... Grinding wheel head origin vicinity detection device, 1
0... Control circuit, 11... Pulse oscillator, 12.13.14.15.20... AND circuit, 16.18... OR circuit, 19...
...Flop. Flop circuit, 21...slit plate, PTO,
P.T.F. PTB...Photoelectric switch.

Claims (1)

[Scope of utility model registration request] A movable body, a motor that moves the movable body via a feed system, a disk connected to the feed system to rotate in conjunction with the movement of the movable body, and a small hole formed in the disk. an origin detection device that allows light to pass through a slit and detects the origin position of the movable body based on the passing state of the light; and an origin detection device that allows light to pass through a slit formed in the target disk and detects the forward direction of the movable body with respect to the origin position based on the passing state of the light. Alternatively, a positional deviation detection device that detects a positional deviation in the backward direction, a near-origin detector that detects that the moving body is near the origin position, a switch that commands return to the origin position, and the origin of this switch. a control device that rotates the motor in either forward or reverse direction according to a positional deviation detection signal from the positional deviation detection device based on a return command; and a control device that rotates the motor in either the forward or reverse direction according to a positional deviation detection signal from the positional deviation detection device, and the switch according to signals from both the origin detection device and the origin proximity detector. A control device for stopping the rotation of the motor by invalidating the origin return command output from the motor.