JPH0970755A - Trueing device of grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trueing device of a grinding wheel which can true the grinding wheel so that a workpiece can be machined with high accuracy. SOLUTION: Since a first detection pin 34a is worn at the time of contact detection of a grinding wheel 22, a tip position of the first detection pin 34a is detected by a touch sensor 50 before the contact detection. After the contact detection, the tip position of the first detection pin 34a is detected by the touch sensor 50. The amount of wear of the first detection pin 34a is calculated based on a difference in the tip positions of the first detection pin 34a which are measured before and after the contact detection. The trueing of the grinding wheel 22 is done based on a value obtained by subtracting the amount of wear of the first detection pin 34a from the travel amount from the grinding wheel 22 to a trueing tool 44 which is measured by the contact detection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention includes a truing tool which is movable relative to a grinding wheel, and a truing tool for truing by cutting a modified grinding surface of the truing tool into a grinding wheel surface of the grinding wheel. Of the truing device.

[0002]

2. Description of the Related Art Conventionally, in a grinding machine, after turing a preset number of works, truing is performed in order to sharpen the grindstone layer. The applicant of this application is
No. 6262 discloses a technique for controlling the cutting amount of the grinding wheel in truing.

In this publication, the distance from the truing tool to the detection pin (hereinafter referred to as step data) is set in advance.
The treading is carried out by bringing the grinding wheel into contact with the detection pin before truing, then adding the truing amount (correction cutting amount) to the step data and moving the grinding wheel to the truing tool side. After truing, a technique is disclosed in which the grinding wheel is brought into contact with the detection pin again to update the step data. Here, the contact detection is an AE (Acoustic Emission) sensor that detects an elastic wave generated in the detection pin when the detection pin made of metal comes into contact with the grinding surface of the grinding wheel, and determines the contact from the signal level. However, it is output as a contact signal.

According to this technique, before truing,
Since the contact position of the grinding wheel is measured by bringing the grinding wheel into contact with the detection pin, the grinding wheel can be cut into a desired fixed amount with respect to the truing tool with reference to the measurement position of the grinding wheel. In addition, before and after truing, the grinding wheel comes into contact with the detection pin to measure the contact position, so the amount of wear of the grinding wheel during truing can be measured, and the actual amount of cut into the grinding wheel can be obtained. The dimension data of the grinding wheel can be updated accurately based on the cutting depth.

[0005]

However, a CBN grindstone (grinding wheel) having a grindstone layer in which CBN abrasive grains are bonded by vitrified bonds is provided on the outer periphery of a metal disk-shaped grindstone core.
Then, if the grindstone layer becomes thin, the signal level when the end surface of the grinding wheel (side surface of the grinding wheel) comes into contact with the detection pin becomes smaller, and more cutting is needed than the outer circumference (circumferential surface side) of the grinding wheel. , The signal level for judging contact may not be reached.
For this reason, the detection pin may be worn during contact detection, and a contact signal may be output at the position where this wear has occurred, causing an error in the contact detection data. Due to the error in the contact detection data, an error occurs between the actual grindstone size and the size on the data for performing the machining, and there is a problem that the dimensional accuracy of the work cannot be ensured during the machining of the work.

That is, when the end face of the grinding wheel is brought into contact with the detection pin for measurement, the detection pin has already been cut by the grinding wheel many times when the acoustic signal from the detection pin is detected by the AE sensor. It is covered, and when contact detection is performed,
Since the detection signal is output at the position where the detection pin is worn,
It is determined that an error has occurred.

Further, in the truing, thermal displacement occurs in the ball screw and the table between the table on which the detection pin and the truing tool are mounted and the grinding wheel table (grinding table) on which the grinding wheel is mounted, so that the truing An error has occurred in the detection data in the front and back measurements.

Due to the above factors, an error occurs between the actual size of the grindstone and the size in the data for machining, and if the workpiece is machined based on this dimensional data, the machining accuracy cannot be secured. It was

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a truing device for a grinding wheel capable of truing a grinding wheel so that a work can be processed with high accuracy. To provide.

[0010]

In order to achieve the above object, a truing apparatus for a grinding wheel according to claim 1 is provided with a truing tool which is movable relative to the grinding wheel, and a corrected grinding surface of the truing tool is provided. A truing device for a grinding wheel that cuts into a grinding wheel surface of the grinding wheel to perform truing, and detects the contact with the grinding wheel surface by relative movement between the grinding wheel and the truing tool. A contact detection unit that includes a pin and a detection unit that detects a contact between the detection pin and the grindstone surface, and a contact detection unit that is moved relative to the grinding wheel integrally with the truing tool; and the grinding wheel and the truing. Drive means for performing relative movement between the tool and the contact detection means,
Position detection means for detecting the relative movement positions of the grinding wheel, the truing tool, and the contact detection means, and the relative movement between the grinding wheel and the truing tool, the pin length of the detection pin Measuring means for measuring, relative contact position data between the grinding wheel and the contact detecting means at the time of detecting contact between the tip of the detection pin and the grindstone surface, relative distance between the tip of the detection pin and the corrected grinding surface First storage means for storing data, correction amount data of the grindstone surface and pin length data of the detection pin, and the tip of the detection pin contacts the grindstone surface before truing, and a contact signal is output from the detection unit. The first contact means for controlling the drive means so as to move the grinding wheel and the truing tool relative to each other, and the relative contact position data between the detection pin and the grindstone surface. After storing in the first storage means,
Second control means for controlling the driving means so as to measure the pin length of the detection pin by the measurement means, and the detection pin of the detection pin stored in the first storage means on the basis of the relative contact position data. In order to move the truing tool and the grinding wheel relative to each other for truing, based on the relative distance data between the tip and the corrected grinding surface, based on the amount of movement in which the amount of correction of the whetstone surface and the old and new pin lengths are added. The gist is that the third control means for controlling the driving means and the second storage means for updating and storing the grindstone dimension data of the grinding wheel based on the correction amount data of the grindstone surface are provided.

Further, in the truing apparatus for a grinding wheel according to a second aspect, in the first aspect, after the pin length obtained by the measuring means is stored in the first storage means, the pin length is determined based on the old and new pin lengths. First calculation means for calculating the amount of change in length is provided, and the third control means uses the relative contact position data as a reference to define the tip of the detection pin stored in the first storage means and the corrected ground surface. The truing tool and the grinding wheel are moved relative to each other for truing on the basis of a movement amount in which the correction amount data of the grindstone surface and the pin length change amount calculated by the first calculating means are added to the relative distance data. The gist is that the driving means is controlled.

Further, in the truing device for a grinding wheel according to a third aspect of the present invention, the truing device according to the first or second aspect is until the tip of the detection pin comes into contact with the surface of the whetstone after the truing and a contact signal is output from the detection section. After storing fourth control means for controlling the driving means so as to move the grinding wheel and the truing tool relative to each other, relative contact position data between the detection pin and the grinding wheel surface after truing in the first storage means. Fifth control means for controlling the driving means so as to measure the pin length of the detection pin by the measuring means, and the second storage means stores the relative contact position data before and after truing and the pin before and after truing. The gist is that the grindstone size data of the grinding wheel is updated and stored based on the length.

Further, in the truing device for a grinding wheel according to claim 4, in claim 3, the pin length obtained by the measuring means is stored in the first storing means, and then based on the pin lengths before and after truing. Second calculation means for calculating the pin length change amount is provided, and the second storage means updates and stores the grindstone size data of the grinding wheel based on the relative contact position data before and after truing and the pin length change amount. The point is to do so.

[0014]

According to the first aspect of the present invention, first, before truing, the driving means is controlled by the first control means until the tip of the detection pin contacts the grindstone surface and a contact signal is output from the detection section. The relative contact position data in which the contact signal between the detection pin and the grindstone surface is detected by the contact detection means is stored in the first storage means by relatively moving the grinding wheel and the truing tool. Next, the driving means is controlled by the second control means, the pin length of the detection pin is measured by the measuring means,
Stored in the first storage means. Next, by the third control means,
Based on the relative contact position data, the relative distance data between the tip of the detection pin and the corrected grinding surface stored in the first storage means, the correction amount data of the grindstone surface, and the current pin length stored in the first storage means ( Truing is performed by moving the truing tool and the grinding wheel relative to each other based on the amount of movement that takes into account the new) and the pin length (old) before being updated. After truing, the grindstone dimension data of the grinding wheel is updated based on the correction amount data of the grindstone surface and stored by the second storage means.

Further, in the configuration of claim 2, after measuring the pin length of the detection pin by the measuring means, the current pin length (new) measured by the first calculating means and the pin length before being updated ( Old) and the pin length change amount is calculated. Next, the third
The control means uses the relative contact position data as a reference, and the first
Based on the relative distance data between the tip of the detection pin and the corrected grinding surface stored in the storage means, based on the movement amount in which the correction amount data of the grindstone surface and the pin length change amount are added, the truing tool and the grinding wheel are relatively moved, Truing is performed. After truing, the grindstone dimension data of the grinding wheel is updated based on the correction amount data of the grindstone surface and stored by the second storage means.

Further, in the structure of claim 3, after truing, the driving means is controlled by the fourth control means so that the tip of the detection pin comes into contact with the grindstone surface and a detection signal is output from the detection section. And move the truing tool relatively,
The relative contact position data after truing in which the contact signal between the detection pin and the grindstone surface is detected by the contact detection means is first.
It is stored in the storage means. Next, the driving means is controlled by the fifth control means, the pin length of the detection pin is measured by the measuring means, and the measured length is stored in the first storage means. Next, the second calculation means calculates the pin length change amount based on the pin lengths before and after truing. Next, the grinding wheel dimension data of the grinding wheel is updated based on the relative contact position data before and after truing and the pin length before and after truing, and stored by the second storage means.

In the structure of claim 4, the driving means is controlled by the fifth control means, the pin length of the detection pin is measured by the measuring means, and the pin length before and after truing is measured by the second calculating means. The pin length change amount is calculated based on Next, the grinding wheel dimension data of the grinding wheel is updated based on the relative contact position data before and after truing and the pin length change amount, and stored by the second storage means.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a cylindrical grinder 10 equipped with a truing device for a grinding wheel according to an embodiment of the present invention. In FIG. 1, a table 14 is supported on a bed 12 so as to be horizontally movable. A headstock 16 and a tailstock 18 are provided on the table 14.
Are arranged so as to face each other, and the work W is attached to one end of the headstock 16.
Is provided with a chuck 16a for gripping one end of the tailstock 1,
8 is provided with a center 18a that supports the other end of the work W as a center. Both ends of the work W are supported by the headstock 16 and the tailstock 18 so that the work rotation axis is parallel to the moving direction of the table 14, and the work W is rotationally driven by the headstock 16. Has become.

The table 14 is further provided with a grinding wheel 22.
A contact detection device 30 for detecting the position of the wheel and a whetstone correction device 40 for setting the whetstone 22 are provided.
In the contact detection device 30, the detection pin head 32 is provided with the first detection pin 34a directed toward the end face side of the grinding wheel 22,
A second detection pin 34b is provided so as to project toward the outer peripheral side of the grinding wheel 22. The detection pin head 32 is supported from the table 14 side by an AE sensor 36 that detects a contact signal when the grinding wheel 22 contacts the first detection pin 34a and the second detection pin 34b. On the other hand, as shown in FIG. 2A, the grindstone correcting device 40 is constituted by a truer tool 42 attached to a truer shaft 42. The truing tool 44 is provided with a first corrected grinding surface 44a for setting the end surface of the grinding wheel 22, a core 44b, and a second corrected grinding surface 44c, and the truer shaft 42 is rotated in the forward and reverse directions by a built-in motor (not shown). It is configured to be rotated by being rotated.

On the other hand, the grindstone 20 is mounted on the bed 12.
The table 14 is guided and supported in a horizontal direction orthogonal to the moving direction of the table 14, and a grinding wheel 22 is supported on the grinding wheel base 20 so as to be rotatable about an axis parallel to the moving direction of the table 14.
As shown in FIG. 2 (A), this grinding wheel 22 is configured by attaching a grinding wheel layer 22b formed by bonding ultra-hard CBN abrasive grains with a vitrified bond to the outer circumference of a thin disk 22a. By pulley,
It is designed to be rotationally driven at a super high speed via a belt (not shown). On the other hand, a touch sensor 50 is arranged at the end of the grindstone 20 on the table 14 side. The touch sensor 50 has a probe 54 for contacting the first detection pin 34a to detect the position, and a measurement head 52 for supporting the probe 54, and a touch sensor 50 and another member during grinding. In order to avoid contact, the turning motor 56 retracts to the position shown by the dotted line in the figure. The touch sensor 5
0 is configured to send a contact signal to the numerical controller 100 when detecting contact with the first detection pin 34a.

Next, the structure of the numerical controller 100 for controlling the cylindrical grinder 10 will be described. Numerical control device 1
Reference numeral 00 denotes a central controller 102 that manages the entire apparatus, a memory 108 that holds various control values and programs,
It is mainly composed of the interfaces 104 and 106. This memory 108 stores a grinding program, a grindstone correction program, grindstone diameter / grindstone width data, data on the relative position of the detection pin and the truing tool, and pin length data of the detection pin. This numerical control device 10
Various data is input to 0 via the input device 110. The input device 110 is a keyboard for inputting data, and C for displaying data.
A display device such as RT is provided. Further, a contact signal from the contact detection device 30 is input to the numerical controller 100 via an amplifier 120. The amplifier 120 is configured to output an on / off signal to the numerical control device 100 side in response to the detection signal from the contact detection device 30.

The numerical controller 100 uses a ball screw (not shown) to feed the grindstone base 20 in a horizontal direction orthogonal to the moving direction of the table 14 by a first servomotor 82.
To the first motor drive circuit 80. The first encoder 84 attached to the first servo motor 82 sends out the rotational position of the first servo motor 82, that is, the position of the grindstone 20 to the first motor drive circuit 80 and the numerical control device 100 side. Is configured. On the other hand, the numerical controller 100 gives a drive signal to the second servo motor 92 for feeding the table 14 in the horizontal direction by a ball screw (not shown) via the second motor drive circuit 90. The second encoder 94 attached to the second servo motor 92 moves the position of the table 14 to
The second motor drive circuit 90 and the numerical control device 100 are configured to send out.

The cylindrical grinding machine 10 starts a truing operation when it is necessary to process a predetermined number of works and correct each grinding wheel surface of the grinding wheel 22. Regarding this truing operation, the explanatory views of FIGS. 2 and 3 and the numerical controller 1
The truing operation of the first grinding wheel surface G1 in which the contact detection in consideration of the wear of the detection pin of the present invention is carried out will be described in detail with reference to the flowcharts of FIGS. First, the numerical control device 100 shown in FIG. 1 controls the first servomotor 82 to send the grindstone 20 to the table 14 side, and the first detection pin 34.
After the first grinding wheel surface (end surface side) G1 of the grinding wheel 22 is positioned to the side of a, the second servomotor 92 is controlled to move the table 14 horizontally, as shown in FIG. Thus, the detection pin 34a is sent to the grinding wheel 22 side (first grinding wheel surface contact feeding: S100 shown in FIG. 4). This contact feeding is continued until the contact signal is detected (No in S101). Then, the first detection pin 34 a and the first grinding wheel surface G of the grinding wheel 22.
1 is detected by the AE sensor 36 and the contact signal is input via the amplifier 120 (S102 returns Y
es), the movement of the table 14 is stopped, and the contact position Z1 of the first grindstone surface G1 is stored (S102).
Then, the table 14 is moved backward by a predetermined amount in FIG. 1, the first grindstone surface G1 is separated from the first detection pin 34a, and the grindstone base 20 is retracted by a predetermined amount. It should be noted that, here, from the time when the first detection pin 34 a contacts the grinding wheel 22 until the contact is detected by the AE sensor 36, the grinding wheel 22.
As a result, the first detection pin 34a is worn and the tip position thereof changes.

Subsequent to the contact detection of the grinding wheel 22 described above, the numerical control device 100 measures the pin length change amount for detecting the pin length change amount (wear amount) of the first detection pin 34a generated at the time of contact detection. The process is started (S103). The pin length change amount measuring process will be described with reference to the flowchart of FIG. 5 showing the subroutine of the process. First, the contact feed of the probe to the detection pin is started (S20).
0). That is, from the retracted state shown by the chain line in FIG. 1, the swing motor 56 is rotated to move the probe 5 as shown by the solid line in the figure.
4 to the table 14 side, and the first servomotor 82
2 to the table 14 side to position the probe 54 on the side of the first detection pin 34a, and then the second servo motor 92 is controlled to perform detection as shown in FIG. 2 (B). The pin 34a is fed in a direction in which the tip of the pin 34a contacts the probe 54. Then, when the tip of the detection pin 34a comes into contact with the probe 54 and the contact signal is sent from the measurement head 52 to the numerical control device 100 (Yes in S201), the numerical control device 100 causes the tip of the first detection pin 34a. The detection position (indicated by B1 in the figure) for is stored (S202). Then, the table 14 is moved backward by a predetermined amount in FIG. 1, the probe 54 is separated from the first detection pin 34a, and the grindstone head 20 is moved backward by a predetermined amount, so that the probe 54 is placed on the side of the end face of the measuring pin head 32. Position it.

After that, the numerical controller 100 starts contact feed of the probe 54 to the end surface of the measuring pin head 32 (S203). When the end surface of the measurement pin head 32 comes into contact with the probe 54 and a contact signal is sent from the measurement head 52 to the numerical control device 100 (Yes in S204), the numerical control device 100 causes the measurement pin head 32 to move.
The detection position (indicated by A1 in the figure) with respect to the end face of is stored (S205). At the same time, the table 14 moves backward to the left by a predetermined amount in FIG.
Away from the end face, and the grinding wheel head 20 retracts by a predetermined amount.

Then, the numerical controller 100 calculates the pin length K1 by subtracting the tip position A1 of the first detection pin 34a from the detection position B1 of the measurement pin head 32, and the pin length stored in the memory 108. Data value K
0 is updated to the value K1 (S206). And grinding wheel 2
The amount of change in the pin length (wear amount) ΔZ1 of the first detection pin 34a that has worn due to contact with 2 and has its tip position changed,
Pin length data value K0 stored in the memory 108
It is calculated by subtracting the data value K1 of the calculated pin length from (the value before the contact of the grinding wheel 22 with the first detection pin 34a is detected) (S207). With the above processing, the subroutine of step 103 is completed, and the processing shown in FIG.
Go to step 104 of the main routine shown in.

In step 104, the above step 207 is performed.
Based on the pin length change amount ΔZ1 calculated in step 1, the step data measured after the truing was previously performed (from the first corrected grinding surface 44a of the truing tool 44 to the first detection pin 3).
The distance to the tip of 4a) H0 is corrected. That is, the step data is replaced with the value of H1 obtained by subtracting the pin length change amount ΔZ1 from the previously measured step data H0. Then, the value T1 (correction cutting amount) for cutting the first grinding wheel surface G1 of the grinding wheel 22 is added to the step data H1 to calculate the movement amount between the grinding wheel 22 and the truing tool 44 (S1).
05). Then, the first detection pin 34a for the first
Step data H1 based on the contact position Z1 of the grindstone surface G1
Based on the movement amount (H1 + T1) in which the correction cut amount T1 is added to the grinding wheel 22, the grinding wheel 22 is relatively sent to the truing tool 44, and the first grinding wheel surface G1 faces the first correction grinding surface 44a of the truing tool 44. Position it at the correction start position. Then, the grindstone base 20 is moved forward, and the first grindstone surface G1 of the grindstone 22 is moved to the first corrected grindstone surface 4 as shown in FIG. 2 (C).
Truing is performed at 4a (S106). The first
The table 1 is divided into a plurality of corrected cutting amounts T1 of the grinding wheel surface G1.
The correction cutting of No. 4 and the correction feed of the grindstone base 20 may be performed a plurality of times. When the correction of the first correction surface G1 is completed, the table 14 is moved backward by a predetermined amount in FIG. 1, the first grinding wheel surface G1 is separated from the first correction grinding surface 44a, and the grinding wheel head 20 is retracted by a predetermined amount.

Then, step 107 and step 10
In step 8, the contact detection of the grinding wheel 22 is performed in the same manner as in step 100 and step 101 described above, and the corrected contact position Z2 of the first grinding wheel surface G1 is determined as shown in FIG. It is detected at 34a. Then, the corrected contact position Z2 of the first grindstone surface G1 is stored in the memory 108 (S109). Note that, here, the first detection pin 34a is worn by the grinding wheel 22 until the AE sensor 36 detects this contact after the detection pin 34a contacts the grinding wheel 22, and the tip position of Change.

Thereafter, the numerical control device 100, as in step 103, as shown in FIG. 3 (B), the first detection pin 34 generated during contact detection after truing.
A pin length change amount measurement process for detecting the pin length change amount (abrasion amount) of a is started (S110). That is, the tip position (indicated by B2 in the figure) of the first detection pin 34a is detected (S200, S201), and the tip position B2 is stored (S202). Subsequently, the position of the end surface of the measurement pin head 32 (indicated by A2 in the figure) is detected (S203, S20).
4) The end face position A2 is stored (S205). Then, from the detection position A2 of the measurement pin head 32 to the detection pin 3
By subtracting the tip position B2 of 4a, the pin length K2
Is calculated, and the value K1 of the pin length data held in the memory 108 is updated to the value K2 (S206). Then, a pin length change amount (wear amount) ΔZ2 of the first detection pin 34a, which has worn due to contact with the grinding wheel 22 after truing and whose tip position has changed, is calculated from the stored pin length data value K1. It is calculated by subtracting the pin length data value K2 (S207).

Subsequently, the numerical controller 100 calculates the actual cutting amount T1 'of the grinding wheel 22 due to the wear of the truing tool 44 due to truing (S111). This cutting amount T1 ′ is determined by the difference in the detection positions of the grinding wheel 22 before and after truing, from the wear amount ΔZ of the first detection pin 34a.
It is calculated by the following formula for subtracting 2.

## EQU1 ## T1 '= Z2-Z1-.DELTA.Z2 = (Z2-Z1)-(K1-K2) = (Z2-Z1)-{(B1-A1)-(B2-A2)} = (Z2-Z1) + (B2-B1) + (A1-A2)

Then, the numerical controller 100 updates the grindstone width based on the calculated actual cutting depth T1 '(S112). That is, the grinding wheel width L1 after truing is calculated by subtracting the cutting amount T1 ′ from the grinding wheel width L0 before truing, and the data value L0 of the grinding wheel width is replaced with the calculated value L1. Then, the wear amount ΔT of the first corrected grindstone surface 44a of the truing tool 44 is calculated (S11).
3). Here, the wear amount ΔT is calculated by subtracting the actual cutting amount T1 ′ of the grinding wheel 22 obtained in S111 from the corrected cutting amount T1 when performing the truing (ΔT = T1−T1 ′). . Finally, the step data is corrected based on the above value (S114). That is, the step data H2 is obtained by subtracting the wear amount ΔZ2 of the first detection pin 34a due to contact detection from the value H1 of the step data when truing is performed and adding the wear amount ΔT of the truing tool.
Is calculated as {H2 = (H1-ΔZ2 + ΔT) = (H1-T
1- (Z2-Z1)}, the value of the step data H2 is held in the memory 108 for the next truing time, and the truing process for the first grinding wheel surface G1 ends.

Next, the second grinding wheel surface G2 is subjected to truing by contact detection similar to the conventional one. Note that FIG.
In (A), R0 is a grindstone diameter before correction, J0 is a distance (step data) between the second corrected grinding surface 44c of the truing tool 44 and the second detection pin 34b, and these grindstone diameter R0 and step data J0. Will be updated from time to time. As described above, the whole process of the truing process is completed.

Since the truing tool 44 and the first detection pin 34a are placed close to each other on the same table 14, it is assumed that the thermal displacement between them is negligible. In the above, the measurement pin head 32 measured for measuring the pin length of the detection pin before and after truing.
Using the data of the end face positions A1 and A2 of the above, the difference between the end face positions of the measurement pin head 32 before and after the truing (A1-
The term A2) may be added. According to this,
The error due to the thermal displacement in the moving direction of the table 14 before and after the truing is corrected.

That is, for example, before and after truing, for example, when the thermal expansion amount of the ball screw driving the table 14 changes and an error occurs due to thermal displacement, in the formula for calculating the actual cutting amount T1 '. Since the difference in contact position before and after truing (Z2-Z1) includes an error due to thermal displacement, add the term of the difference in end face position (A1-A2) of the measuring pin head 32 before and after truing, which corresponds to the thermal displacement error. As a result, the relative deviation (error) between the table 14 and the grindstone base 20 caused by thermal displacement in the moving direction of the table 14 before and after the truing is eliminated.

Next, a truing apparatus for a grinding wheel according to a second embodiment of the present invention will be described with reference to FIG. In the first embodiment described above with reference to FIGS. 2 and 3, the position of the first grinding wheel surface G1 (end surface) of the grinding wheel 22 is detected by the probe 54 arranged parallel to the moving direction of the grinding wheel head 20. On the other hand, in the second embodiment shown in FIG. 6, the probe 54 is arranged parallel to the moving direction of the table 14, and
Detection pin 3 for detecting the second grinding wheel surface G2 (outer peripheral surface) of
4b can be detected. That is, after the position of the second grinding wheel surface G2 of the grinding wheel 22 is detected by the second detection pin 34b, the second detection pin 3 is detected by the probe 54.
It is configured to detect the pin length of 4b and correct the pin length change amount. In the second embodiment, the accuracy of radial contact detection of the grinding wheel 22 can be improved.

Next, a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the truing tool 44 of the grindstone correcting device 40 is attached to the grindstone wheel 22.
First modified grinding surface 44a for truing the first grinding wheel surface G1, second modified grinding surface 44c for truing the second grinding wheel surface G2, and first modification for truing the third grinding wheel surface G3. And a grinding surface 44d. Further, the detection pin head 32 of the contact detection device 30 has a first detection pin 34a for detecting the first grinding wheel surface G1 of the grinding wheel 22 and a second detection pin 3 for detecting the second grinding wheel surface G2.
4b and a first detection pin 34c for detecting the third grindstone surface G3.
And are attached. Then, the probe 54 is arranged vertically to the table 14 on the measuring head 52 of the touch sensor 50 as shown in FIG. 7A, and the first, second and third detection pins 34a, 34b, 34c are provided. Is configured so that all can be detected.

In the third embodiment, each of the grinding wheel surfaces G1, G2 and G3 of the grinding wheel 22 is attached to each of the detection pins 34a and 34.
After detecting the respective positions by b and 34c, the probe 54 detects the pin lengths of the respective detection pins 34a, 34b and 34c and corrects the pin length change amount.

In the third embodiment, it is possible to improve the accuracy of the grinding wheel width data when truing both grinding wheel surfaces G1 and G3 of the grinding wheel 22. Therefore, in FIG.
As shown in (B), when the work W having the step portions D1 and D2 adjacent to the cylindrical portion is processed, the width accuracy of both the step portions D1 and D2 of the work can be secured.

In the above-described embodiment, the moving amount in which the corrected cutting amount is added to the step data is calculated during truing, and the table 14 is moved based on the calculated moving amount. Each data may be sequentially read from the memory 108, and the feeding operation may be performed based on each distance data from the contact position.

Further, in the above embodiment, taking into consideration the fact that the truing tool 44 is worn during truing, the contact of the grindstone surface is detected before and after the truing, and the grindstone data is updated from the contact position data before and after the truing. However, assuming that the truing tool 44 does not wear during truing, contact detection is performed only before truing, considering contact pin wear, and after truing, the data of the predetermined cutting amount of the grinding wheel surface for the truing tool 44 is used. The grindstone data may be updated.

Furthermore, in the above-mentioned embodiment, the example in which the CBN grindstone is used as the grindstone is given, but it goes without saying that the truing apparatus for the grinding wheel of the present invention can be applied to the case where a normal grindstone is used. .

[0042]

As described above, in the invention of claim 1 or 2, after detecting the contact of the grinding wheel surface of the grinding wheel, the detection pin wear amount (pin length change amount) is measured to detect the detection pin. Since the relative movement amount at the time of truing was corrected based on the wear amount of, the grinding wheel can be accurately cut into the truing tool, and based on the corrected cutting amount that is cut accurately, Since the grindstone dimension data of the grinding wheel is updated, the data regarding the grindstone dimension is accurately managed, and high-precision machining can be realized.

In addition to the effect of claim 1, in the invention of claim 3 or claim 4, after detecting the contact of the grinding wheel surface of the grinding wheel after truing, the wear amount of the detection pin is similarly measured. However, since the grindstone size data of the grinding wheel is updated based on the relative contact position data before and after truing and the wear amount of the detection pin, in addition to the effect of claim 1, an error due to the truing tool wear during truing Can be eliminated, and more accurate processing can be realized by more accurately managing the data regarding the size of the grindstone.

[Brief description of drawings]

FIG. 1 is a plan view of a cylindrical grinder equipped with a truing device for a grinding wheel according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a truing operation by the cylindrical grinder shown in FIG.

FIG. 3 is an explanatory view showing a truing operation by the cylindrical grinding machine shown in FIG.

FIG. 4 is a flowchart of a truing operation by a numerical control device that controls the cylindrical grinding machine shown in FIG.

5 is a flowchart of a subroutine of a pin length change amount measuring process of the detection pin shown in FIG.

FIG. 6 is an explanatory view showing a truing device for a grinding wheel according to a second embodiment of the present invention.

FIG. 7 is an explanatory view showing a truing device for a grinding wheel according to a third embodiment of the present invention.

[Explanation of symbols]

 10 Cylindrical grinder 14 Table 20 Wheel head 22 Wheel wheel 30 Contact detection device 34a 1st detection pin 40 Grinding wheel correction device 44 Truing tool 50 Touch sensor 54 Probe 100 Numerical control device

Claims (4)

[Claims] 1. A truing apparatus for a grinding wheel, comprising a truing tool movable relative to a grinding wheel, wherein a corrected grinding surface of the truing tool is cut into a grinding wheel surface of the grinding wheel to perform truing. There, a detection pin protruding to the grindstone surface and contacting the grindstone surface by relative movement of the grinding wheel and the truing tool,
A contact detection unit that includes a detection unit that detects contact between the detection pin and the grindstone surface, and that is relatively moved between the truing tool and the grindstone wheel; and the grindstone wheel and the truing tool; Drive means for performing relative movement with the contact detection means, position detection means for detecting relative movement positions of the grinding wheel and the truing tool and the contact detection means, and the truing tool integrally with the grinding wheel Relative movement between, the measuring means for measuring the pin length of the detection pin, relative contact position data of the grinding wheel and the contact detection means at the time of contact detection of the tip of the detection pin and the grindstone surface, First storage means for storing relative distance data between the tip of the detection pin and the corrected grinding surface, correction amount data for the grindstone surface, and pin length data for the detection pin; Prior to ruining, first control means for controlling the driving means so as to relatively move the grinding wheel and the truing tool until the tip of the detection pin comes into contact with the grindstone surface and a contact signal is output from the detection section. And a second control for controlling the driving means so as to measure the pin length of the detection pin by the measuring means after storing relative contact position data between the detection pin and the grindstone surface in the first storage means. Means and the relative contact position data as a reference, the correction amount data of the grindstone surface and the old and new pin lengths are added to the relative distance data between the tip of the detection pin and the corrected grinding surface stored in the first storage means. Third control means for controlling the driving means so as to relatively move the truing tool and the grinding wheel based on the added movement amount for truing; 2. A truing device for a grinding wheel, comprising: a second storage means for updating and storing the grinding wheel dimension data of the grinding wheel based on the positive amount data. 2. The truing device for a grinding wheel according to claim 1, wherein after the pin length obtained by the measuring means is stored in the first storage means, the pin length change amount is calculated based on the old and new pin lengths. First calculation means for calculating is provided, and the third control means uses the relative contact position data as a reference to calculate relative distance data between the tip of the detection pin and the corrected grinding surface stored in the first storage means. The driving means is arranged to relatively move the truing tool and the grinding wheel on the basis of the movement amount in consideration of the correction amount data of the grindstone surface and the pin length change amount calculated by the first calculating means. A truing device for a grinding wheel characterized by being controlled. 3. The truing device for a grinding wheel according to claim 1, wherein after truing, the tip of the detection pin comes into contact with the surface of the grindstone until the contact signal is output from the detection section. Fourth control means for controlling the driving means so as to move the vehicle and the truing tool relative to each other; and after storing relative contact position data between the detection pin and the grindstone surface after truing in the first storage means, Fifth control means for controlling the driving means to measure the pin length of the detection pin by the measuring means is provided, and the second storage means stores the relative contact position data before and after truing and the pin length before and after truing. A truing apparatus for a grinding wheel, wherein the grinding wheel dimension data of the grinding wheel is updated and stored based on the above. 4. The truing apparatus for the grinding wheel according to claim 3, wherein after the first storage means stores the pin length obtained by the measuring means, the pin length change based on the pin length before and after truing. A second calculation means for calculating the amount is provided, and the second storage means updates and stores the grinding wheel dimension data of the grinding wheel based on the relative contact position data before and after truing and the pin length change amount. A truing device for grinding wheels.