JPH11277426A - Grinder and grinding surface measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a position measuring error of a grinding surface due to thermal displacement of a wheel spindle stock relative to a work table, or grinding of a material to be ground. SOLUTION: A grinder moves a wheel spindle stock 40 relative to a work table 20 relatively to grind a work on the work table 20 by a rotary grinding wheel 42 provided at the wheel spindle stock 40. Then, the grinder is provided with a detecting sensor 52 installed at a specified position of the wheel spindle stock 40 to detect a predetermined position of the work table 20, a material 25a to be ground which is provided at a specified position of the work table 20, a sensor position measuring means for measuring a distance from an origin to the detecting sensor 52, and a grinding wheel-grinding wheel surface position measuring means which moves the wheel spindle stock 40 and the work table 20 until the material 25a to be ground is ground by a grinding surface 42s of the rotary grinding wheel 42 and the surface ground of the material 25a to be ground is detected by the detecting sensor 52, and which measures the distance between the detecting sensor 52 and the grinding surface 42s of the rotary grinding wheel 42 based on the relative displacement of the wheel spindle stock and the work table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinder and a method of measuring a ground surface by relatively moving a grindstone table and a work table to grind a work of a work table with a rotary grindstone provided on the grindstone table.

[0002]

2. Description of the Related Art When grinding a workpiece, it is necessary to accurately grasp the position of the grinding surface of the rotating grindstone. Therefore, at present, a contact detector is brought into contact with the grinding surface of the rotating grindstone to grind the grinding surface. Is detected. Hereinafter, FIG.
A method of detecting the position of the grinding surface of the rotary grindstone using the contact detector based on (A) will be described. Here, the work table 1 has a structure capable of moving in the axial direction of the main spindle (Z-axis direction, the horizontal direction in FIG. 12), and the whetstone table 2 has a structure capable of moving at right angles to the work table 1 (X-axis direction). It is.

On the workpiece table 1, a reference block 1b is fixed at a predetermined position.
A measuring pin 1p extending in the Z-axis direction is attached to the distal end surface of the point b. Further, the reference block 1b houses an AE sensor (not shown) for detecting a wave of sound when the tip of the measuring pin 1p comes into contact with the grinding surface 3s of the rotating grindstone 3.

Accordingly, the workpiece table 1 is advanced (moved to the right) from a state in which the tip of the measuring pin 1p is positioned at the origin (see the two-dot chain line), and the tip of the measuring pin 1p is moved to the grinding surface 3s of the rotary grindstone 3. When the AE sensor detects the timing of contact with the AE sensor, the moving distance Ref of the workpiece table 1 at this time is the distance from the origin to the grinding surface 3s of the rotary grindstone 3, that is, the position of the grinding surface 3s.

The work table 1 is provided with a grindstone correcting mechanism 1x at a predetermined position behind the reference block 1b, and a distance from the grindstone correcting surface 1s of the grindstone correcting mechanism 1x to the tip of the measuring pin 1p. D is measured in advance. For this reason, the workpiece table 1 is moved by a distance D from the position where the tip of the measuring pin 1p contacts the grinding surface 3s of the rotating grindstone 3.
Is advanced, the grindstone correction surface 1s of the grindstone correction mechanism 1x can be brought into contact with the grinding surface 3s of the rotary grindstone 3 (see FIG. 12B).

Therefore, when truing the grinding surface 3s of the rotary grindstone 3, the workpiece table 1 is further advanced from this state by a predetermined truing amount T (see FIG. 12 (C)). The position of the grinding surface 3s of the rotating grindstone 3 after the truing is measured by bringing the tip of the measuring pin 1p into contact with the grinding surface 3s of the rotating grindstone 3 as described above.

[0007]

However, in the above-mentioned grinding machine, the tip of the measuring pin 1p is connected to the grinding surface 3s of the rotating grindstone 3s.
, And the position of the ground surface 3s is measured, so that if the measuring pin 1p is shaved, a measurement error increases. Further, when the grindstone table 2 is thermally displaced with respect to the workpiece table 1 while the grinding surface 3s of the rotary grindstone 3 is being trued, the thermal displacement becomes an error in the position measurement of the ground surface 3s after truing. . Further, the wear of the rotary grindstone 3 and the thermal displacement of the grindstone table 2 with respect to the workpiece table 1 are simultaneously generated by the work of the work.
Since the wear and the thermal displacement cannot be separately grasped, an error occurs in the position measurement of the grinding surface 3s of the rotary grindstone 3.

Therefore, the invention according to claims 1 to 7 of the present invention is designed to prevent the measurement pin from being affected by the shaving of the measuring pin and the thermal displacement of the grinding wheel table with respect to the workpiece table.
It is an object of the present invention to accurately measure the positions of a grinding surface of a rotary grinding wheel and a grinding wheel correction surface of a grinding wheel correction mechanism.

[0009]

The above-mentioned object is achieved by a grinding machine having the following features. That is, the grinding machine according to claim 1, wherein the grindstone table and the workpiece table are relatively moved to grind a workpiece on the workpiece table with a rotary grindstone provided on the grinding stone table. Is provided at a predetermined position, a detection sensor for detecting a predetermined portion of the work table, a workpiece to be provided provided at a predetermined position of the work table, and a distance from the origin to the detection sensor. A sensor position measuring means for measuring and grinding the workpiece with the grinding surface of the rotary grindstone, and relatively moving the grindstone table and the workpiece table until the ground surface of the workpiece is detected by the detection sensor. ,
It has a grinding wheel grinding surface position measuring means for measuring the distance between the detection sensor and the grinding surface of the rotary grinding wheel from the relative movement distance.

According to the present invention, the distance from the origin to the detection sensor provided on the grinding wheel head can be measured by the sensor position measuring means. In this case, the position of the detection sensor can be accurately grasped. Furthermore, since the distance from the detection sensor to the grinding surface of the rotary grindstone can be measured by the grinding wheel grinding surface position measuring means, the sensor position measuring means and the grinding wheel grinding surface position measuring means measure the distance from the origin to the grinding surface of the rotating grinding wheel. The distance, that is, the position of the ground surface can be measured. The grinding wheel grinding surface position measuring means grinds the workpiece with the grinding surface of the rotating grindstone, and moves the grinding wheel base and the workpiece table relative to each other until the ground surface of the workpiece is detected by the detection sensor. Since the distance between the detection sensor and the ground surface is measured from the relative movement distance, there is no measurement error caused by cutting the workpiece. For this reason, the position measurement accuracy of the grinding surface of the rotating grindstone is improved.

According to a second aspect of the present invention, in the grinding machine according to the first aspect, the sensor position measuring means shifts the position of the reference point of the workpiece table from the origin to a position of the workpiece. The table and the grindstone table are relatively moved, and the relative movement distance between the workpiece table and the grindstone table until the reference point is detected by the detection sensor is measured.

According to the present invention, the position of the detection sensor, that is, the distance from the origin to the detection sensor is obtained from the relative movement distance between the work table and the grinding wheel head. The position of the detection sensor can be measured using the position detection means. For this reason, the equipment cost of the sensor position measuring means can be reduced.

The grinding machine according to a third aspect of the present invention is the grinding machine according to the first or second aspect, further comprising grinding determination means for determining whether the workpiece has been cut. I have.

According to the present invention, it is possible to determine whether or not the measurement of the ground surface has been correctly performed by the grinding determination means. For this reason, a trouble that the work is ground based on the incorrect grinding surface position data does not occur.

According to a fourth aspect of the present invention, in the grinding machine according to the first, second, or third aspect, the grinding surface of the rotary grindstone is an outer peripheral surface of the rotary grindstone. ADVANTAGE OF THE INVENTION According to this invention, the position measurement of the outer peripheral surface of the rotary grindstone used as a grinding surface can be performed accurately.

According to a fifth aspect of the present invention, in the grinding machine according to the first, second, or third aspect, the grinding surface of the rotary grindstone is an end surface of the rotary grindstone. ADVANTAGE OF THE INVENTION According to this invention, the position measurement of the end surface of the rotary grindstone used as a grinding surface can be performed accurately.

According to a sixth aspect of the present invention, there is provided a grinding machine according to the second, third, fourth, or fifth aspect, wherein a grinding wheel mounted at a predetermined position on a workpiece table is fixed. By moving the mechanism, the workpiece table and the grindstone table relative to each other, and detecting the reference point of the workpiece table and the grindstone correction surface of the grindstone correction mechanism with the respective detection sensors, the distance from the reference point to the grindstone correction surface is determined. Correction surface position measuring means for measuring.

According to the present invention, the relative movement between the work table and the grindstone base is made by moving the work table relative to the grindstone base from the time when the reference point of the work table is detected by the detection sensor to the time when the grindstone correction surface is detected by the detection sensor. The position of the grinding wheel correction surface with respect to the reference point can be obtained from the distance. For this reason, the position of the grindstone correction surface of the grindstone correction mechanism can be accurately measured using the work table or the existing position detection means of the grindstone table.

According to a seventh aspect of the present invention, there is provided a grinding surface measuring method for measuring a grinding wheel grinding surface position of a grinding machine provided with a grinding wheel base and a workpiece table which are relatively movable in two directions perpendicular to the axial direction of the work. A grinding surface measurement method, wherein a predetermined sensor on a workpiece table is detected by a detection sensor attached to the grindstone table to detect a position of the predetermined component, and the detection sensor detects a predetermined position on the workpiece table. The tip of the first material to be ground is detected based on the position of the part and the position of the tip of the material to be ground, based on the position of the part and the position of the tip of the material to be ground. After the position is determined, the grindstone table and the workpiece table are relatively moved to grind the material to be ground with a grindstone, and then, again, the tip of the material to be ground is detected by the detection sensor, and the position of the tip of the material to be ground is determined. Detect and before From the position of the part and the position of the tip of the material to be ground, the position of the tip of the second material to be ground is determined based on the position of the part, and the grindstone is determined based on the position of the tip of the first and second materials to be ground. Measuring the grinding surface position

According to the present invention, the relative movement between the grindstone table and the work table allows the position of the ground surface to be accurately measured with reference to a predetermined portion on the work table.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A grinding machine according to one embodiment of the present invention will be described below with reference to FIGS. 1 to 8 are plan views showing the operation of the grinding machine, FIG. 9 is a side view of a contact sensor used in the grinding machine, FIG. 10 is an overall plan view of the grinding machine, and FIG. It is a wiring block diagram of a grinder. In the following description, the axis direction of the main shaft of the workpiece table is the Z-axis direction, the moving direction of the grindstone table is the X-axis direction, and the height direction is the Y-axis direction.

As shown in FIG. 10, the grinding machine 10 has a work table 20 for supporting a work W and a grindstone table 40 having a rotating grindstone 42. The work table 20 is mounted on a pair of Z-axis rails 13,
The movement of the Z-axis rail 13 can be performed by the action of the ball screw & nut 14. At the end (left side in FIG. 10) of the Z-axis rail 13, a table moving servomotor 15 for driving the ball screw & nut 14 is installed. An encoder 15e for measuring the amount of movement of the table 20 is connected.

As shown in FIG. 11, the pulse signal of the encoder 15e is input to the drive circuit 110 of the servo motor for moving the table, and the numerical controller 1
00 is input to the CPU via the interface IF. Then, the movement amount and the current position of the work table 20 are monitored by integrating the pulse signals from the encoder 15e. Further, the driving circuit 110
Drives the table moving servomotor 15 based on the table position command from the CPU.

A spindle head 24 and a tailstock 23 are fixed on the workpiece table 20. The work W is moved in the Z-axis direction by a spindle 24m of the spindle head 24 and a center 23s of the tailstock 23. It is sandwiched and supported from both sides. Further, on the side surface of the spindle head 24, a reference block 2 serving as a measurement reference for the grinding surface 42s of the rotary grindstone 42 and the like is provided.
5, a first measuring pin 25a, a second measuring pin 25b, and a third measuring pin 25c
Is attached.

A grindstone correction device 26 is provided on the side surface of the spindle head 24 at a position retracted from the reference block 25 by a predetermined distance. The grindstone correcting device 26 includes a disc-shaped truer 27 for reshaping the grinding surface 42s of the rotary grindstone 42, and a truer rotation motor 26m for rotating the truer 27.

On the other hand, the grindstone table 40 is mounted on a pair of X-axis rails 17 and can move following the X-axis rail 17 by the action of a ball screw & nut 44.
At the end (upper side in FIG. 10) of the X-axis rail 17, a grinding wheel head moving servomotor 18 for driving the ball screw & nut 44 is installed. An encoder 18e for measuring the amount of movement of the wheel head 40 is connected.

As shown in FIG. 11, the pulse signal of the encoder 18e is input to the drive circuit 120 of the servomotor for moving the grinding wheel head, and the numerical controller 10
0 is input to the CPU through the interface IF. Then, the moving amount and the current position of the grinding wheel head 40 are monitored by integrating the pulse signals from the encoder 18e. Further, the driving circuit 120 includes a CPU
The servomotor 18 for moving the grinding wheel head is driven based on the command from.

On the carriage 44, a grindstone bearing 45 for supporting the grindstone shaft 42j in parallel with the Z axis, and the grindstone shaft 42j
A grindstone motor 46 for rotating the wheel is provided, and a disc-shaped rotating grindstone 42 is coaxially attached to an end of the grindstone shaft 42j. A contact sensor 50 for detecting contact with the reference block 25, the first measuring pin 25a, and the like is mounted on the grinding wheel bearing 45.

As shown in FIG. 9, the contact sensor 50 includes an arm 54 having a contact 52 at the distal end, and a support mechanism 56 for supporting the base end of the arm 54 in a rotatable state. ing. The rotation center of the base end of the arm 54 is positioned so as to be orthogonal to the axis of the grinding wheel shaft 42j. Here, since a low thermal expansion material is used as the material of the arm 54, a measurement error caused by thermal expansion can be almost ignored. The contact sensor 50 has a moving motor 58 for moving the arm 54 and the contact 52 from the measurement position to the standby position or vice versa.
Is installed. The sensor is an analog type,
Two types of digital type are prepared.

As shown in FIG. 11, a signal from the contact sensor 50 is sent to the CPU via an interface IF.
Is input to Thus, the timing at which the reference block 25 or the like comes into contact with the contact sensor 50 is input to the CPU and stored in the memory. That is, the contact sensor 50 functions as the detection sensor of the present invention. The memory stores a grinding NC program, a grinding wheel correction program, a position setting program, and the like. The input device shown in FIG.
It means T or the like.

Next, the operation of the grinding machine according to the present embodiment will be described with reference to FIGS. First, the left grinding surface 42 of the rotating grindstone 42 when the rotating grindstone 42 is replaced
A method for measuring the position of s will be described with reference to FIGS.
First, the distance from the origin to the contact 52 of the contact sensor 50, that is, the position of the contact 52 is measured. At this time, the workpiece table 20 has been returned to its original position (see the two-dot chain line in FIG. 6), and the reference surface 25k of the reference block 25 mounted on the spindle head 24 of the workpiece table 20.
Is positioned at the origin. That is, the reference surface 25k
Corresponds to the reference point of the workpiece table of the present invention. First, the grinding wheel head moving servomotor 18 is driven to move the grinding wheel head 40 to the work table 20 side.
The zero contact 52 is positioned at a position where the reference surface 25k can be measured (a position where the contact 52 and the reference surface 25k face each other in the Z-axis direction).

Next, the table moving servomotor 15 is driven, and the work table 20 is moved rightward (forward direction) in FIG. At this time, since a pulse corresponding to the rotation angle of the table moving servomotor 15 is output from the encoder 15e (see FIG. 11), the number of pulses is integrated so that the work table 20 based on the original position is referenced. A position is required.

As the workpiece table 20 moves forward, as shown in FIG. 6A, when the reference surface 25k of the reference block 25 comes into contact with the contact 52 of the contact sensor 50, the contact sensor 50 Operates and the data Re of the position of the workpiece table 20 at that timing.
f0 (hereinafter referred to as position Ref0) is stored. Here, the position Re of the workpiece table 20 with respect to the original position
Since f0 is equal to the distance that the reference plane 25k at the origin has moved to the position of the contact 52, the position Ref0 is eventually obtained.
Is equal to the distance from the origin to the contact 52. That is,
The position of the contact 52 is Ref0.

Next, the length of the first measuring pin 25a is measured. First, the workpiece table 20 moves left (retreats) and returns to the original position. Next, the grindstone table 40 moves and the contact 52 of the contact sensor 50 is positioned at a position where the first measuring pin 25a can be measured. In this state, the workpiece table 20 advances from the original position. Then, as shown in FIG. 6B, the first measurement pin 2
The position a of the workpiece table 20 at the timing when the tip end surface of the workpiece 5 a contacts the contact 52 is stored. That is, the value obtained by subtracting the position a from the position Ref0 of the contact 52 already measured is the length P0 (= Ref0−) of the first measurement pin 25a.
a). As described above, the encoder 15e of the table moving servomotor 15, the drive circuit 110, the numerical controller 100, and the like function as the sensor position measuring means of the present invention.

Next, the position of the left grinding surface 42s of the rotary grindstone 42 is measured. First, the workpiece table 20 is returned to the original position. Next, the grindstone table 40 is moved to position the rotating grindstone 42 at a position where the first measuring pin 25a can be cut, and the rotating grindstone 42 rotates. In this state, the workpiece table 20 moves forward by a predetermined distance from the original position. Then, as shown in FIG. 7A, the position b of the work table 20 is stored in a state where the tip of the first measuring pin 25a is shaved by the left grinding surface 42s of the rotating grindstone 42.

When the position b is stored, the workpiece table 20 is returned to the original position, the rotation of the rotary grindstone 42 is stopped, and the grindstone table 40 moves to a predetermined position.
Then, the contact sensor 50 attached to the grinding wheel head 40
Is positioned at a position where the first measuring pin 25a can be measured. In this state, the work table 20
Moves forward from the original position. Then, as shown in FIG. 7B, the distal end surface of the first measuring pin 25a is
The position c of the workpiece table 20 at the timing of contact with is stored.

Next, the length P1 of the first measuring pin 25a after being cut as described above is calculated. That is, the length P1 of the first measurement pin 25a is obtained by (Ref0-c). If the length P1 of the first measurement pin 25a is smaller than the initial length P0 (P1 <P0), the first measurement pin 2
It is determined that 5a has been reliably ground by the left grinding surface 42s of the rotary grindstone 42. That is, the first measuring pin 25a functions as the material to be ground according to the present invention, and the numerical control device 10
0 functions as the grinding determination means of the present invention.

When the positions b and c are measured in this manner, the position of the left grinding surface 42s of the rotary grindstone 42 is obtained by calculation. That is, the value obtained by subtracting the position b from the position c becomes equal to the distance G0 from the left grinding surface 42s of the rotary grindstone 42 to the contact 52 of the contact sensor 50 (FIG. 7).
reference). Here, since the position Ref0 of the contact 52 has already been measured, the distance from the origin to the left grinding surface 42s of the rotating grindstone 42, that is, the position of the left grinding surface 42s is (Ref0
−G0). When the first measuring pin 25a is not cut (when P1 is substantially equal to P0), the positions b and c are measured again after the first measuring pin 25a is cut again. That is, the encoder 15e, the drive circuit 110, the numerical controller 100, and the like function as a grinding wheel surface position measuring means of the present invention.

When the position of the left grinding surface 42s of the rotary grindstone 42 is obtained in this way, the position of the truer 27 of the grindstone correcting device 26 is measured (see FIG. 8). First,
The workpiece table 20 is returned to the original position. Next, the grindstone table 40 moves to a predetermined position, and the contact 52 of the contact sensor 50 is positioned at a position where the truer 27 can be measured. In this state, the workpiece table 20 advances from the original position. Then, the position Tr of the workpiece table 20 at the timing when the grindstone correction surface 27s of the truer 27 comes into contact with the contact 52 is stored.

As described above, since the contact 52 of the contact sensor 50 is located at the distance Ref0 from the origin, the distance D0 from the reference surface 25k of the reference block 25 to the grindstone correction surface 27s of the truer 27 is (Tr-Ref0). ).
That is, the encoder 15e, the numerical controller 100, and the like function as the corrected surface position measuring means of the present invention. When the position measurement of the left grinding surface 42s of the rotating grindstone 42 and the grindstone correction surface 27s of the truer 27 is completed, the workpiece W is continuously ground using the left grinding surface 42s of the rotating grindstone 42. FIG. 1A shows the position of each part before grinding the workpiece W.

When grinding of a predetermined number of works W is completed, truing of the left grinding surface 42s of the rotary grindstone 42 is performed. Next, based on FIGS. 1 to 5,
Grinding surface 42 of rotary whetstone 42 before and after truing
A method of measuring the position of s and the position of the grinding wheel correction surface 27s of the truer 27 will be described.

First, a method for measuring the position of the left grinding surface 42s of the rotary grindstone 42 will be described with reference to FIGS. First, the position of the contact 52 of the contact sensor 50 is measured again in consideration of the fact that the grindstone table 40 is thermally displaced with respect to the workpiece table 20 due to the grinding of the work W.
Therefore, the work table 20 is first returned to the original position. Next, the wheel head 40 is moved, and the contact 52 of the contact sensor 50 is positioned at a position where the reference surface 25k can be measured.

In this state, the workpiece table 20 advances from the original position. Then, the reference surface 25 of the reference block 25
The position Ref1 of the workpiece table 20 at the timing when k contacts the contact 52 is stored (FIG. 1).
(B)). That is, the position of the contact 52 is Ref1. Therefore, the thermal displacement of the grindstone table 40 with respect to the workpiece table 20 after the continuous grinding of the workpiece W is Ref1-R
ef0.

Next, the position of the left grinding surface 42s of the rotary grindstone 42 is measured. First, the workpiece table 20 is returned to the original position. Next, the grindstone table 40 is moved to position the rotating grindstone 42 at a position where the first measuring pin 25a can be cut, and the rotating grindstone 42 rotates. In this state, the workpiece table 20 advances by a predetermined distance from the original position. Then, as shown in FIG. 2A, the tip of the first measuring pin 25a is connected to the left grinding surface 4 of the rotary grindstone 42.
The position e of the workpiece table 20 is stored in a state where the workpiece table 20 is cut by 2s.

When the position e is stored, the work table 20 is returned to the original position, the rotation of the rotary grindstone 42 is stopped, and the grindstone table 40 moves to a predetermined position.
Then, the contact sensor 50 attached to the grinding wheel head 40
Is positioned at a position where the first measuring pin 25a can be measured. In this state, the work table 20
Moves forward from the original position. Then, as shown in FIG. 2B, the tip surface of the first measuring pin 25a is
The position f of the workpiece table 20 at the timing of contact with is stored.

When the position e and the position f are measured in this manner, the position of the left grinding surface 42s of the rotary grindstone 42 is obtained by calculation. That is, the value obtained by subtracting the position e from the position f becomes equal to the distance G1 from the left grinding surface 42s of the rotary grindstone 42 to the contact 52 of the contact sensor 50 (FIG. 2).
reference). Here, since the position Ref1 of the contact 52 has already been measured, the distance from the origin to the left grinding surface 42s of the rotating grindstone 42, that is, the position of the left grinding surface 42s is (Ref1).
-G1). If the first measuring pin 25a is not cut, the positions e and f are measured again after the first measuring pin 25a is cut again.

Next, a method of measuring the amount of reduction of the rotary grindstone 42 and the amount of reduction of the truer 27 due to truing will be described with reference to FIGS. First, the workpiece table 20 is returned to the original position. Next, the wheel head 40 moves,
The rotating grindstone 42 is positioned at a position where it can abut the truer 27. In this state, the rotating whetstone 42 and the truer 27
Rotates, and the workpiece table 20 advances from the original position.

Here, the position of the left grinding surface 42s of the rotary grindstone 42 is (Ref1-G1), and the distance from the grindstone correction surface 27s of the truer 27 to the reference surface 25k of the reference block 25 is D0 (= Tr-Ref0). ). For this reason,
As shown in FIG. 3A, the work table 20
Is advanced from the original position by (Ref1-G1 + D0), the grinding wheel correction surface 27s of the truer 27 comes into contact with the left grinding surface 42s of the rotary grinding wheel 42.

Therefore, if the workpiece table 20 is further advanced from this position by the distance T, the truing of the left grinding surface 42s of the rotary grindstone 42 can be performed with the cutting amount T as shown in FIG. Become like When the truing is completed in this way, the rotation of the rotary grindstone 42 and the truer 27 is stopped, and the workpiece table 20 is returned to the original position.

Next, the grindstone table 40 moves to rotate the grindstone 42.
Is positioned at a position where the first measuring pin 25a can be shaved, and the rotating grindstone 42 rotates. In this state, the workpiece table 20 advances by a predetermined distance from the original position.
Then, as shown in FIG. 4A, the position h of the workpiece table 20 is stored in a state where the tip of the first measuring pin 25a is cut by the left grinding surface 42s of the rotary grindstone 42.

When the position h is stored, the work table 20 is returned to the original position, the rotation of the rotary grindstone 42 is stopped, and the grindstone table 40 moves to a predetermined position.
Then, the contact sensor 50 attached to the grinding wheel head 40
Is positioned at a position where the first measuring pin 25a can be measured. In this state, the work table 20
Moves forward from the original position. Then, as shown in FIG. 4B, the distal end surface of the first measuring pin 25a is
The position j of the workpiece table 20 at the timing of contact with is stored.

When the position h and the position j are measured as described above, the position of the left grinding surface 42s of the rotary grindstone 42 is obtained by calculation. That is, the value obtained by subtracting the position h from the position j becomes equal to the distance G2 from the left grinding surface 42s of the rotary grindstone 42 to the contact 52 of the contact sensor 50 (FIG. 4).
reference). Here, since the position Ref1 of the contact 52 has already been measured, the distance from the origin to the left grinding surface 42s of the rotating grindstone 42, that is, the position of the left grinding surface 42s is (Ref1).
-G2). If the first measuring pin 25a has not been shaved, the positions j and h are measured again after the first measuring pin 25a is shaved again.

For this reason, the truing rotary whetstone 4
The reduction amount of 2 is obtained by calculating the difference between the position of the left ground surface 42s before truing and the position of the left ground surface 42s after truing. That is, the reduction amount of the rotary grindstone 42 is G1-G2. Therefore, the truer 27
Is a value obtained by subtracting the reduction amount (G1-G2) of the rotary grindstone 42 from the cutting amount T of the truing, that is, T-
It is represented by (G1-G2). For this reason, the grinding wheel correction surface 27s of the truer 27 and the reference surface 25k of the reference block 25
The distance D2 to is represented by D0 + T- (G1-G2). Note that the distance D0 is the whetstone correction surface 27 before truing.
This is the distance between s and the reference plane 25k.

Next, in consideration of the fact that the grindstone table 40 is thermally displaced with respect to the work table 20 by truing, the position of the contact 52 of the contact sensor 50 is measured, and then the first measuring pin 25a is measured. Is measured. Therefore, the work table 20 is first returned to the original position. Next, as shown in FIG. 5, the grinding wheel head 40 is moved, and the contact 52 of the contact sensor 50 is moved to the reference surface 25k.
Is positioned at a position where measurement can be performed.

In this state, the workpiece table 20 moves forward from the original position. Then, the reference surface 25 of the reference block 25
The position of the workpiece table 20 at the timing when k contacts the contact 52, that is, the position Ref of the contact 52
2 is stored. Therefore, the length P2 of the first measurement pin 25a is obtained by P2 = (Ref2-j). In this way, when the grindstone correction surface 27s of the truer 27 after the truing, the left grinding surface 42s of the rotating grindstone 42, the length P2 of the first measuring pin 25a, and the like are obtained, the work is performed using the grinding machine 10 again. Continuous grinding of W is performed.

As described above, in the grinder according to the present embodiment, the position of the contact 52 of the contact sensor 50 provided on the grindstone table 40 is measured before measuring the grinding surface 42s of the rotary grindstone 42. In addition, the influence of the thermal displacement of the grindstone table 40 on the work table 20 after the work W is processed or during truing can be ignored. Also, the first measuring pin 25a
After shaving the tip of the grinding wheel 42s with the grinding surface 42s of the rotating grindstone 42, the grindstone table 40 and the workpiece table 20 are relatively moved to bring the shaved surface of the first measuring pin 25a into contact with the contact 52,
Since the distance between the contact 52 and the ground surface 42s is measured from the relative movement distance, there is no measurement error caused by cutting the first measuring pin 25a.

That is, since the position measurement accuracy of the grinding surface 42s of the rotary grindstone 42 is improved, the work grinding accuracy is also improved. Further, the timing for replacing the rotating grindstone 42 can be accurately grasped, and the life of the grindstone becomes appropriate.

Since the distance between the origin and the contact 52 can be measured from the movement amount of the work table 20, the position of the contact sensor can be measured using the existing encoder 15e of the work table 20. Can be. For this reason, the equipment cost of the sensor position measuring means can be reduced. Further, since means for determining whether or not the first measuring pin 25a has been cut is provided, the ground surface 42s
It can be grasped whether or not the measurement such as was performed correctly. For this reason, a trouble that the work W is ground based on the incorrect position data of the ground surface 42s does not occur.

Since the position of the grinding wheel correction surface 27s of the truer 27 can be measured from the movement amount of the work table 20 in the same manner as the measurement of the grinding surface 42s, the existing encoder 15e of the work table 20 is used. Thus, the position of the grindstone correction surface 27s can be measured. For this reason, the equipment cost of the correction surface position measuring means can be reduced.

Here, in the present embodiment, the method of measuring the position of the rotating grindstone 42 on the left grinding surface 42 s has been described, but the position of the right grinding surface 42 u of the rotating grindstone 42 is also determined by the third measuring pin 25 c of the reference block 25. Can be measured in the same way as above. Further, the position of the outer peripheral grinding surface 42t of the rotary grindstone 42 can also be measured from the movement amount of the grindstone table 40 using the second measuring pin 25b of the reference block 25, etc., in the same way. Further, a method using the work W instead of the measuring pin is also possible.

Further, in the grinding machine 10 according to the present embodiment, the ball screw & nut 14 is used as a moving mechanism of the work table 20 and the grindstone table 40.
It is also possible to use a pinion, a linear motor or the like. Also, using the contact sensor 50, the reference block 2
5, the tip positions of the reference surface 25k, the measurement pin 25a, and the like are detected.
It is also possible to detect k and the like. Furthermore, in the grinding machine 10 according to the present embodiment, the work table 20 and the grindstone table 40 move at a right angle, but the work table 20 and the grindstone table 40 may not be at a right angle.

Although the embodiments of the present invention have been described above, it should be noted that the embodiments of the present invention have the following technical matters in addition to the technical matters described in the claims. Keep it. (1) In the grinding machine according to claim 2, the material to be ground is attached to a reference point of a work table,
A grinder for measuring the length of a workpiece by relatively moving the workpiece table and the grindstone base and detecting a reference point of the workpiece table and the tip of the workpiece by a detection sensor. The length of the workpiece can be measured using the existing position detecting means of the workpiece table or the grinding wheel head. (2) The grinding machine according to claim 3, wherein the grinding determining means detects the presence or absence of grinding by comparing the length of the workpiece. The determination of the presence or absence of grinding becomes reliable.

[0063]

According to the present invention, since the position measurement accuracy of the grinding surface of the rotary grindstone is improved, the grinding accuracy of the work is also improved. Further, the timing for replacing the rotating grindstone can be accurately grasped, and the life of the grindstone becomes appropriate.

[Brief description of the drawings]

FIG. 1 is a schematic plan view illustrating an operation of a grinding machine according to one embodiment of the present invention.

FIG. 2 is a schematic plan view illustrating an operation of the grinding machine according to one embodiment of the present invention.

FIG. 3 is a schematic plan view illustrating an operation of the grinding machine according to one embodiment of the present invention.

FIG. 4 is a schematic plan view illustrating an operation of the grinding machine according to one embodiment of the present invention.

FIG. 5 is a schematic plan view illustrating an operation of the grinding machine according to one embodiment of the present invention.

FIG. 6 is a schematic plan view illustrating an operation of the grinding machine according to one embodiment of the present invention.

FIG. 7 is a schematic plan view illustrating an operation of the grinding machine according to one embodiment of the present invention.

FIG. 8 is a schematic plan view illustrating the operation of the grinding machine according to one embodiment of the present invention.

FIG. 9 is a side view of a contact sensor used in the grinding machine according to one embodiment of the present invention.

FIG. 10 is an overall plan view of a grinding machine according to one embodiment of the present invention.

FIG. 11 is a wiring block diagram of a grinding machine according to one embodiment of the present invention.

FIG. 12 is a schematic plan view illustrating the operation of a conventional grinding machine.

[Explanation of symbols]

 15 Servo motor for moving table 15e Encoder 18 Servo motor for moving wheel head 18e Encoder 20 Work table 25 Reference block 25k Reference surface (reference point) 25a First measuring pin (material to be ground) 40 Wheel head 50 Contact sensor (detection sensor) ) 100 Numerical control device

Claims (7)

[Claims] 1. A grinder for relatively moving a grindstone table and a work table to grind a work of a work table with a rotary grindstone provided on the grindstone table. A detection sensor for detecting a predetermined portion of the workpiece table; a workpiece to be ground provided at a predetermined position on the workpiece table; and a sensor position measuring means for measuring a distance from the origin to the detection sensor. The material to be ground is ground with a grinding surface of a rotary grindstone, and the ground surface of the material to be ground is detected by a detection sensor,
A grinding machine having a grindstone surface position measuring means for relatively moving a grindstone table and a workpiece table and measuring a distance between a detection sensor and a grinding surface of a rotary grindstone from the relative movement distance. 2. The grinding machine according to claim 1, wherein the sensor position measuring means relatively moves the workpiece table and the grindstone table from a state in which a reference point of the workpiece table is positioned at an origin, A grinding machine for measuring a relative movement distance between a workpiece table and a grinding wheel stand until the reference point is detected by a detection sensor. 3. The grinding machine according to claim 1, further comprising: a grinding determination unit configured to determine whether or not the workpiece has been cut. 4. The grinding machine according to claim 1, wherein the grinding surface of the rotating grindstone is an outer peripheral surface of the rotating grindstone. 5. The grinding machine according to claim 1, wherein the grinding surface of the rotating grindstone is an end surface of the rotating grindstone. 6. The grinding machine according to claim 2, wherein the grinding wheel is mounted at a predetermined position on a work table, and the work table and the grindstone table. Relative movement, by detecting the reference point of the workpiece table and the grindstone correction surface of the grindstone correction mechanism with a detection sensor, respectively, correction surface position measuring means for measuring the distance from the reference point to the grindstone correction surface, Having a grinding machine. 7. A grinding surface measuring method for measuring a grinding wheel grinding surface position of a grinding machine provided with a grindstone table and a work table which can be relatively moved in two directions orthogonal to the axial direction of a work, The attached detection sensor detects a predetermined part on the workpiece table to detect the position of the part, and the detection sensor detects the tip of the material to be ground provided on the workpiece table. Detecting the tip position of the material to be ground, obtaining the tip position of the first material to be ground based on the position from the position of the part and the position of the tip of the material to be ground, After the relative movement and grinding of the material to be ground with a grindstone, the tip of the material to be ground is again detected by the detection sensor, and the position of the tip of the material to be ground is detected. Tip position Surface measuring method for determining the position of the tip of the second workpiece based on the position of the part, and measuring the location of the grinding surface of the grinding wheel based on the tip of the first and second workpieces .