JP2018069358A - Grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding machine improved in workability of manual grinding work required to be carefully performed.SOLUTION: A grinding machine comprises: a grindstone for grinding a work-piece; a nozzle which jets cooling liquid to the work-piece; manual operation handles 41 and 42 which are rotationally operated by a worker; a proximity sensor 53 which detects a proximity state between the work-piece and the grindstone 4; a control unit 50 which makes the work-piece to approach/contact the grindstone by controlling servo motors 61 and 62 at speed corresponding to rotation speed of the manual operation handles 41 and 42; and notification devices (21, 31 and 54) which notify the worker. The control unit 50 notifies the worker of the proximity state using the notification devices in response to the proximity sensor 53, and slows down the speed at which the work-piece W is made to approach the grindstone 4 in comparison with the rotation speed of the manual operation handles 41 and 42 before and after the proximity state, or temporarily stops relative movement of the work-piece W and the grindstone 4 when the work-piece and the grindstone are in the proximity state.SELECTED DRAWING: Figure 2

Description

The present invention relates to an NC machine having a manual feed handle in which an operator can manually move and move the position of a grindstone relative to a workpiece, and more particularly, to a grinding machine with improved workability during handle operation.

As an NC machine having a manual feed handle in which an operator can manually move the position of the grindstone relative to the workpiece, for example, Patent Document 1 discloses a table feed manual feed handle and a grindstone table feed manual feed handle. The pulse generator generates a pulse corresponding to the rotation amount from each hand feed handle, inputs the pulse to the control unit, and outputs the control amount corresponding to the pulse from the control unit to the servo motor. A CNC (computer numerical control) grinder with a manual operation mode for moving the position of a table or grindstone is described.

In addition, the conventional hydraulic grinder moves the relative position of the grindstone with respect to the workpiece by directly applying pressure to the hydraulic fluid for moving the relative position of the grindstone with respect to the workpiece. As a grinding machine that simulates the operation feeling of this hydraulic grinding machine by an NC machine having a manual feed handle, for example, a grinding machine disclosed in Patent Document 2 is known. In this grinding machine, when it is detected that the distance between the workpiece and the grindstone is close, the rotational torque of the manual feed handle is made variable, and the weight of the manual feed handle is felt.

Similarly, Patent Document 3 discloses a technique for enabling an operator to obtain a feeling close to that when operating a hydraulic grinder, such as feeling resistance to the operation of the steering wheel after the grindstone contacts the workpiece using a brake. Has been.

JP 2006-123138 A JP2015-157345A JP 2001-38578 A

When operating the manual feed handle to bring the grindstone closer to the workpiece, the operator rotates the handle while checking the preset coordinate value on the display device so that they do not collide. If there is a difference between the actual distances and if they are unintentionally in strong contact with each other, there is a risk of adversely affecting the machining quality. Not only checking the value, but also checking the actual gap between the two visually, and further visually checking the sparks generated by the contact between the two, while checking the visual information, requires careful operation.

According to Patent Document 2, it is possible to let the worker experience the state in which the grindstone and the workpiece are close to each other in advance through the manual feed handle, and attempts have been made to provide further information on the tactile sense of the worker. . However, as a means for making the rotational torque variable, a means for pressing the brake pad against the shaft of the manual feed handle by a piston is used, and there is a limit on the response speed. Moreover, in order to detect that the space | interval of a workpiece | work and a grindstone approached, an acoustic sensor, a gap sensor, a distance measurement sensor, etc. are shown as an illustration of a detection means. In the gap sensor, the distance measurement sensor, or the like, the proximity state based on the distance measurement value is detected in advance. Even when proximity is detected using such a detection means, the response speed of the means for varying the rotational torque is slow, so that grinding has progressed when the operator feels contact. On the other hand, when the acoustic sensor is used, since the actual contact is detected instead of the proximity between the workpiece and the grindstone, the grinding further proceeds. Also in patent document 3, since a handle | steering-wheel is braked after determining a contact, grinding progresses further. As a means for varying the rotational torque, a powder brake or the like is also known, but there is a limit in response speed.

An object of this invention is to provide the grinding machine which improved the workability | operativity of the manual grinding operation | work which requires careful operation.

In order to solve the above problems, a grinding machine according to the present invention comprises a grindstone for grinding a workpiece,
A nozzle that jets coolant to the workpiece;
A manual feed handle that is rotated by an operator;
A proximity sensor that detects the proximity state of the workpiece and the grindstone;
A moving device that moves the workpiece and the grindstone, and changes the relative position between them;
A control unit for controlling the moving device so that the workpiece and the grindstone come close to / contact with each other at a speed corresponding to the rotational speed of the manual feed handle;
A notification device for notifying the worker,
In response to the detection information of the proximity sensor, the control unit notifies the operator of the proximity state using the notification device, and at the same time, a workpiece with respect to the rotational speed of the manual feed handle before and after the proximity state, The speed at which the grindstone is brought close is slowed down, or the relative movement between the workpiece and the grindstone is temporarily stopped in the proximity state.

According to the present invention, when the grindstone is in a state immediately before contact with the workpiece, the feeding speed is slowed or temporarily stopped, so that it is avoided that the grindstone cuts into the workpiece at the same speed. it can. In addition, since the worker is notified that the state is immediately before contact, the worker can recognize that the speed mode has been changed or that there has been a pause.

It is a perspective view explaining the external appearance of one embodiment of a grinding machine. It is a system block diagram of a grinding machine. It is a figure which shows an operation | movement flow.

Hereinafter, the present invention will be described using embodiments for carrying out the present invention. FIG. 1 shows the appearance of the grinding machine 1. The grinding machine 1 includes a bed 10, a work table 5, a grindstone 4, a grindstone base 6 that supports the grindstone 4, a spindle device 7, and a tailstock 8. In the drawing, the X-axis direction indicates the direction in which the grindstone 4 cuts into the workpiece W, and the Z-axis direction indicates the feed direction of the work table 5. The X axis and the Z axis are orthogonal to each other. The grinding machine 1 includes display devices 21, 22, and 23 using liquid crystal panels, various input keys 31, 32, and 33, a manual feed handle 41 in the X-axis direction, and a manual feed handle 42 in the Z-axis direction. The functions of the display devices 21, 22, 23 and the input keys 31, 32, 33 may be provided together using a touch screen or a touch panel. The display devices 21, 22, and 23 display an operator input (setting) state to the grinding machine 1, an operation state of the grinding machine 1, and the like. The various input keys 31, 32, and 33 receive inputs such as switching between the automatic operation mode and the manual operation mode by the operator and various settings. Among these, the display device 21 and the input key 31 are arranged in the vicinity of the manual feed handle 41, and information relating to feed in the X-axis direction is input / output. Further, the display device 22 and the input key 32 are arranged in the vicinity of the manual feed handle 42, and information relating to feed in the Z-axis direction is input / output. Reference numeral 71 denotes a nozzle that ejects the coolant 72 between the workpiece W and the grindstone 4.

FIG. 2 shows a system configuration diagram of the grinding machine 1. The control unit 50 is a computer and executes a control program. Pulse generators 51 and 52 for converting the rotation of the manual feed handles 41 and 42 into pulses are provided. The grinding wheel base 6 is moved in the X-axis direction by a servo motor 61 (corresponding to a moving device). The work table 5 is moved in the Z-axis direction by a servo motor 62 (corresponding to a moving device). By these moving devices, the workpiece W and the grindstone 4 are moved, and the relative positions of the two are changed. Pulse generators 51 and 52 are connected to the control unit 50. Further, the control unit 50 controls the servo motors 61 and 62 via the drive unit 56, and the display devices 21, 22 and 23 and the input keys 31, 32 and 33 are connected to the control unit 50. Light emitting elements such as LEDs are incorporated in the input keys 31, 32, and 33, and the key tops of the input keys 31, 32, and 33 can be turned on by the control unit 50. Further, a proximity sensor 53 and a vibrator 54 are connected to the control unit 50. The proximity sensor 53 detects the proximity state between the workpiece W and the grindstone 4 and gives proximity information to the control unit 50. The vibrator 54 is incorporated in the manual feed handles 41 and 42, and can be given vibration to the hand of the operator by the control unit 50.

Next, the grinding operation in the grinding machine 1 will be described. In the following description, the phrase “displayed on the display devices 21, 22, and 23” includes display on any one of them unless otherwise specified. Further, the phrase “input to the input keys 31, 32, 33” includes any one input unless otherwise specified. The control unit 50 is programmed with a control program so as to execute an automatic grinding operation mode and a manual grinding operation mode. Which mode is selected can be input to the input keys 31, 32, and 33. First, the workpiece W is sandwiched and fixed by the spindle device 7 and the tailstock 8. The control unit 50 detects the position (work position) of the workpiece W in the X-axis direction and the Z-axis direction with a contact (not shown) and sets it in the internal memory 58. The grindstone position of the memory 58 is the position of the grindstone 4 in the X-axis direction and the Z-axis direction. Thereafter, the control unit 50 displays the grindstone position (X-axis direction and Z-axis direction) and the workpiece position (X-axis direction and Z-axis direction) on the display devices 21, 22 and 23.

When performing the automatic grinding operation, the NC program for the grinding work is added to the control program of the control unit 50 by inputting information about the grinding of the workpiece W to the input keys 31, 32 and 33 in the grinding machine 1. Let it be created. Based on the NC program, the control unit 50 rotates the spindle device 7 to rotate the workpiece W. On the other hand, after the grindstone 4 is rotated, the grindstone 4 is automatically controlled by controlling the servo motor 61 and the servo motor 62. Grind the workpiece W.
At this time, the servo motors 61 and 62 are rotated by being supplied with pulses from the control unit 50, and the respective servo motors 61 and 62 have their rotational speeds determined by the number of pulses transmitted thereto, The rotational speed is determined by the amount of pulses transmitted per time.

Next, when a manual grinding operation is performed, the manual feed handles 41 and 42 are in a state where they can be used effectively. The operator rotates one hand feed handle 42 with the right hand, and rotates the other hand feed handle 41 with the left hand. When each manual feed handle 41, 42 is rotated, the input part of the corresponding pulse generator 51, 52 is rotated in conjunction with this, and the number of pulses corresponding to the rotation amount is at a speed corresponding to the rotation speed. Generated. If each hand feed handle 41, 42 is rotated quickly, the number of pulses transmitted per time increases. The control unit 50 generates pulses corresponding to these pulses and transmits them to the drive unit 56 to drive the servo motors 61 and 62. The control unit 50 can change the rotation speed of the servo motors 61 and 62 according to the speed mode, and can change the ratio of the pulses transmitted to the drive unit 56 to the pulses generated by the manual feed handles 41 and 42.

As a result, each of the servo motors 61 and 62 rotates in a direction corresponding to the sign of the supplied pulse by an angle corresponding to the number of pulses at a speed corresponding to the pulse supply speed. The movement of the relative position is controlled. As a result, the grindstone 4 and the workpiece W come close to / contact with each other, and the operator grinds by confirming the gap between the grindstone 4 and the workpiece W by actual visual observation of the both, and visually confirming the spark generated by the contact between the two. Do work.

In the present embodiment, the proximity sensor 53 is attached to the grindstone base 6. As the proximity sensor 53, a gap sensor, a distance measurement sensor, or the like may be used. Moreover, the vibrator 54, the display devices 21, 22, and 23 and the input keys 31, 32 and 33 are used as a device for notifying the worker that the vehicle is in the proximity state. Other than the vibrator 54, the notification is visual, and the vibrator 54 is a tactile notification. In addition, an auditory notification device using a speaker may be used.

When the operator rotates the manual feed handles 41 and 42 in the manual grinding operation, the relative position of the grindstone 4 with respect to the workpiece W changes. In the grinding machine 1, as described below, the control unit 50 controls the pulse interval generated by the pulse generators 51 and 52 when the manual feed handles 41 and 42 are rotated in accordance with the proximity state of the grindstone and the workpiece. Performs a control to delay the rotation of the servo motors 61 and 62 or temporarily stop the rotation for 1 second to several seconds by changing the pulse interval at the time of transmission to the drive unit 56.

Next, the operation when the grindstone 4 is moved in the X-axis direction relative to the workpiece W according to the rotation of the manual feed handle 41 will be described with reference to FIG. FIG. 3 shows an operation flow of the control unit 50, FIG. 3A is a part of the control program, and FIG. 3B is a notification subroutine. In the manual grinding operation, the notification subroutine of FIG. 3B is called by the control program.

When the hand feed handle 41 is rotated and the grindstone 4 is moved relative to the workpiece W in the X-axis direction, the control program of the control unit 50 causes N pulses for one pulse of the pulse generator 51. A pulse is generated so as to be a pulse, and is sent to the drive unit 56. In the memory 58 inside the control unit 50, the grindstone position in the X-axis direction of the grindstone 4 is updated and reflected on the display devices 21, 22, and 23 (FIG. 3A, step S1). This operation is the same as a normal grinder. In the grinding machine 1 of the present embodiment, the control program periodically calls a notification subroutine (FIG. 3A, step S2).

When the grindstone 4 approaches 1 mm (first proximity state) with respect to the workpiece W, the control unit 50 detects this in step S11 and proceeds to step S12. When the distance is more than 1 mm, the control program is returned to the control program because it is not yet in a predetermined close state.

In step S12, the vibrator 54 is operated as a notification device to the worker to notify the 1 mm approaching state (first approaching state). It is determined whether proximity is detected by the proximity sensor 53 (step S13). If not detected, it returns to the control program because it is not in a state immediately before contact. When approaching several micrometers to several tens of micrometers, the proximity sensor 53 detects this and outputs a signal. When this signal is detected (specifically, at a signal level corresponding to a distance of 10 micrometers), the control unit 50 is in a state (second proximity state) immediately before the grindstone 4 contacts the workpiece W. Judgment is made and control is passed to step S14.

In step S14, the speed mode for slowing the rotation of the servo motor 61 is changed. This change in the feed rate is because, in step S1 of the control program, the pulse is generated so that there are N pulses for one pulse of the pulse generator 51. Return to the control program to generate M pulses. Here, M is smaller than N. After the speed mode is changed, the number of pulses transmitted from the control unit 50 to the drive unit 56 becomes the number of pulses in the new speed mode, and the approach speed between the grindstone 4 and the workpiece W decreases. When the change of the speed mode is executed, the operator is notified that the change of the speed mode has been executed using the display devices 21, 22, and 23 as a notification device. Alternatively, the input keys 31, 32, and 33 may be used as a notification device to turn on or blink the internally mounted light emitting element to notify that the state is just before contact. When step S14 ends, the process returns to the control program.

In step S14, step S15 may be executed before the speed mode change and / or in place of the speed mode change as indicated by the broken line. In step S15, when the proximity sensor 53 detects that it has approached 10 micrometers, the pulse generator 51 generates a pulse for the period (1 second to several seconds) set by the timer 57 provided in the control unit 50. In contrast, a new pulse is not sent to the drive unit 56. The timer 57 is a timer that is updated by the operation clock of the control unit 50. If the flag 59 is set so that the flag 59 is referred to before the execution of step S1 of the control program, a new pulse is not sent to the drive unit 56 for the pulse generation of the pulse generator 51. S1 is ended. In step S15, the timer 57 and the flag 59 are set in the initial operation, and thereafter, while the timer 57 is inspected, the flag 59 remains set until a predetermined time elapses. As a result, during the period set by the timer 57, the control unit 50 stops sending pulses to the drive unit 56 during the period set by the timer 57, and the X-axis direction approach operation is temporarily stopped.

According to the present embodiment, the feed speed is slowed or temporarily stopped when the grindstone 4 and the workpiece W are in a state immediately before contact. By slowing the speed at which the workpiece W and the grindstone 4 are brought close to / contact with respect to the rotational speed of the handle 41 before and after the proximity state, or by temporarily stopping the relative movement between the workpiece W and the grindstone 4 in the proximity state, Can be prevented from flowing into the workpiece W at the same speed. Moreover, since it is notified to an operator by a display apparatus that it is a state just before a contact, an operator can recognize that there was a speed mode change or there was a temporary stop.

In the above-described embodiment, the embodiment may be modified so that the pause process in step S15 is executed together with the speed mode change process in step S14. In this case, inflow grinding due to the reaction delay of the operator can be prevented, and thereafter the moving speed can be reduced. On the other hand, even when the pause process in step S15 is executed instead of the speed mode change process in step S14, the display devices 21, 22, 23 or the input keys 31, Since it is notified by the light emitting devices 32 and 33 that the state is immediately before contact, it is possible to prevent inflow grinding due to a delay in the operator's reaction.

The operation when the grindstone 4 is moved in the X-axis direction relative to the workpiece W according to the rotation of the manual feed handle 41 has been described with reference to FIG. The operation when moving the grindstone 4 relative to W in the Z-axis direction is the same.

The configuration for moving the grindstone in the X-axis direction relative to the workpiece is not limited to the configuration described in the present embodiment, and it is sufficient that the grindstone can be moved relative to the workpiece in the X-axis direction. Similarly, the configuration for moving the grindstone with respect to the workpiece in the Z-axis direction is not limited to the configuration described in this embodiment, and it is sufficient that the grindstone can be moved relative to the workpiece in the Z-axis direction.

Further, according to the above-described embodiment, Patent Document 3 shows a state in which the state immediately before contact is notified to the operator before contact and the speed is changed or temporarily stopped and the grindstone and the workpiece are actually contacted thereafter. In order to increase the rotational resistance when operating the handle artificially using a brake (for example, powder brake) installed in the handle unit to bring out the reality of contact, the contact state between the grindstone and the work must be maintained May be fed back to the operator by force.

In the above embodiment, the operator is notified of the state immediately before contact in the state immediately before contact, but is displayed when the state is close to about 1 millimeter using the grindstone position and the work position in the memory 58. The notification of the proximity state by the devices 21, 22, and 23 may be made, and the speed mode may be changed or temporarily stopped together with this. In this case, the proximity sensor 53 is realized by a program such as step S11 in FIG. 3B that detects the proximity state by comparing the grindstone position in the memory 58 with the workpiece position. According to this embodiment, since the speed mode is changed or temporarily stopped at a point substantially before the actual contact, the workability is inferior compared with the case of 10 micrometers. Currently, it is a few micrometers with a grinding machine with high machining accuracy.

In the above-described embodiment, when it is determined that the grindstone 4 is in a state immediately before contact with the workpiece W (second proximity state), the speed mode is changed using the display devices 21, 22, and 23 as notification devices. Notify the worker that this has been done. Alternatively, the input key 31, 32, 33 is used as a notification device, and the light emitting element mounted inside is turned on or blinked. A vibrator other than the vibrator 54 is combined with this to display the display devices 21, 22, 23. The operator may be notified of the change of the speed mode by using at least one of the light emitting elements and the vibrator or a combination of two or a combination of all three.

DESCRIPTION OF SYMBOLS 1 Grinding machine 4 Grinding wheel 5 Work table 6 Grinding wheel base 7 Spindle device 8 Tailstock 10 Bed 21, 22, 23 Display device 31, 32, 33 Input key 41, 42 Manual feed handle 50 Control unit 51, 52 Pulse generator 53 Proximity sensor 54 Vibrator 56 Drive unit 57 Timer 58 Memory 59 Flag 61, 62 Servo motor 71 Nozzle 72 Coolant W Workpiece

Claims (3)

A grinding wheel for grinding the workpiece,
A nozzle that jets coolant to the workpiece;
A manual feed handle that is rotated by an operator;
A proximity sensor that detects the proximity state of the workpiece and the grindstone;
A moving device that moves the workpiece and the grindstone, and changes the relative position between them;
A control unit for controlling the moving device so that the workpiece and the grindstone come close to / contact with each other at a speed corresponding to the rotational speed of the manual feed handle;
A notification device for notifying the worker,
In response to the detection information of the proximity sensor, the control unit notifies the operator of the proximity state using the notification device, and at the same time, a workpiece with respect to the rotational speed of the manual feed handle before and after the proximity state, A grinding machine characterized by slowing a speed at which a grindstone is brought close, or temporarily stopping a relative movement between a workpiece and the grindstone in a close state.
The control unit notifies the operator that the workpiece and the grindstone are in the first proximity state using the notification device when the workpiece and the grindstone are close to the first proximity state, and is closer to the first proximity state. The notification of being in the second proximity state when approaching two proximity states and the speed at which the workpiece and the grindstone are brought close to the rotation speed of the manual feed handle are slowed, or the workpiece and the grindstone are in the proximity state 2. The grinding machine according to claim 1, wherein the relative movement of the grinding machine is temporarily stopped.
2. The grinding machine according to claim 1, wherein the notification device is at least one of a display device, a light emitting element, and a vibrator, or a combination of two or more.