JP2012171062A - Method and device for measuring revolution center of grinding stone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for measuring a revolution center of a grinding stone capable of measuring, with a high degree of accuracy, a position of an actual rotation center point in relation to a position of a grinding stone reference point of a grinding wheel.SOLUTION: The grinding wheel 42 is positioned at first to fourth revolution angle positions to determine positional relationships between four plate reference points P0 and a controlled revolution center Cc. Then, from the four positional relationships, and a known dimensions of a master plate 24, and the like, a relationship between a grinding stone reference point Pg of the grinding wheel 42 and an actual revolution center point Cr is geometrically calculated. According to this method, improved is a shape accuracy of a grinding stone in truing for shaping an R form of the grinding wheel 42 by revolving a grinding stone table 40.

Description

  The present invention is a grinding machine capable of relative movement between the headstock and the wheelhead and turning of the wheelhead relative to the headstock, and grinding a workpiece mounted on the headstock by a grinding wheel mounted on the wheelhead. The present invention relates to a method and an apparatus for measuring a turning center of a grindstone.

  For example, Japanese Patent Laid-Open No. 2000-94322 (Patent Document 1) discloses a grinding wheel for a workpiece using a touch probe attached to a grinding wheel base, a reference block and a transfer rod fixed to the spindle head in a grinding machine. Is described. That is, the touch probe is brought into contact with the reference block, and the positional relationship between the rotational axis of the grinding wheel and the rotational axis of the main shaft is obtained. Next, the tip of the transfer rod is ground with a grinding wheel, and the position of the tip of the transfer rod is measured with a touch probe to determine the radius of the grinding wheel. Then, the outer diameter position of the grinding wheel relative to the workpiece is obtained from the positional relationship between the rotational axis of the grinding wheel and the rotational axis of the main shaft and the radius of the grinding wheel.

  Further, for example, in Japanese Patent Application Laid-Open No. 9-70755 (Patent Document 2), in a grinding machine, movement with respect to a truing tool of a grinding wheel is performed using a touch sensor attached to a grinding wheel base and a detection pin fixed to the spindle head. It is described that the amount is corrected. That is, before and after grinding the tip of the detection pin with the grinding wheel, the position of the tip of the detection pin is measured by the touch sensor to obtain the wear amount. And based on the calculated amount of wear, the amount of movement of the grinding wheel relative to the truing tool is corrected.

  The methods described in Patent Documents 1 and 2 described above are applied to a grinding machine in which a headstock and a grinding wheel base move relative to each other in an orthogonal direction. It cannot be applied. On the other hand, for example, in Japanese Patent Laid-Open No. 3-55159 (Patent Document 3), in a grinder equipped with a swivel capable of turning a grindstone, a coordinate position of a grinding tip point of a grindstone is detected. Are listed. That is, the first displacement of the grinding tip point of the grinding wheel when the swivel base is swung from an arbitrary position to the first swivel position is obtained. Next, the second displacement of the grinding tip point of the grinding wheel when the swivel base is turned from the first turning position to the second turning position is obtained. Then, based on the obtained first and second displacements and the turning angle, the coordinate position of the grinding tip point of the grinding wheel is detected.

JP 2000-94322 A JP-A-9-70755 JP-A-3-55159

  The method described in Patent Document 3 described above detects the coordinate position of the grinding tip point of the grinding wheel based on the first and second displacements and the turning angle. The turning angle is obtained based on the turning center point on the control data of the control device of the grinding machine. However, the turning center point on the control data may differ from the actual turning center point due to a manufacturing error of the grinding machine, thermal displacement, or the like. For this reason, an error occurs in the detected coordinate position of the grinding tip of the grinding wheel.

  As a result, in truing that forms the R shape of the grinding wheel by turning the grinding wheel base, an error occurs between the grinding wheel locus calculated by the control device and the actual grinding wheel locus, which may result in a grinding wheel shape error. In addition, when grinding is performed with a grinding wheel by turning the grinding wheel head, an error occurs in the workpiece dimensions, and it is necessary to correct the dimensions for each turning angle of the grinding wheel base.

  The present invention has been made in view of such circumstances, and a grinding wheel turning center measuring method and a grinding wheel turning capable of accurately measuring the position of the actual turning center point with respect to the position of the grinding wheel reference point of the grinding wheel. An object is to provide a central measuring device.

(Wheelstone turning center measurement method)
(Claim 1) The grinding wheel turning center measuring method of the present invention is capable of relative movement between a headstock and a grinding wheel base and turning of the grinding wheel base with respect to the headstock, and a workpiece mounted on the headstock is A grinding machine for grinding with a grinding wheel mounted on a grinding wheel table, a plate reference point for measuring the position of a grinding wheel reference point of the grinding wheel, and a plurality of plate references for contacting a cylindrical surface or an end surface of the grinding wheel In a grinding wheel turning center measuring method comprising a master plate having a surface and measuring a position of an actual turning center point with respect to a position of the grinding wheel reference point of the grinding wheel, a cylindrical surface or an end surface of the grinding wheel is set at different turning angles. Different from the cylindrical surface or end surface of the grinding wheel that has been brought into contact with the plate reference surface at least four times, and at least one of the plate reference surfaces is in contact with the other plate reference surface. A contact step for contacting a surface, a calculation step for calculating a positional relationship between the plate reference point and a control turning center point by the contact step, and a positional relationship between the plate reference point and the plate reference surface And a turning center calculation step of calculating a positional relationship between the grinding wheel reference point and the actual turning center point from a positional relationship between the plate reference point and the turning center point on the control.

  (Claim 2) The master plate is provided with a plurality of pins that are perpendicular to the plurality of plate reference planes and that can contact the rotating grinding wheel, respectively, A position measuring means capable of measurement is attached, and the abutting step abuts the cylindrical surface or the end surface of the grinding wheel at least four times at different turning angles, and at least one of the pins has another one of the aforementioned Determining a position of a contact point between the grinding wheel and the pin by contacting a surface different from a cylindrical surface or an end surface of the grinding wheel abutted on the pin; and a position of the plate reference surface by the position measuring means; A step of measuring a position of a contact point of the pin, and the calculating step includes a position of a contact point between the grinding wheel and the pin, a position of the plate reference surface measured by the position measuring means, and a contact point of the pin Place of Based on the positional relationship between the pivot point on the control and the plate reference point may be located in the step of calculating.

  (Claim 3) When the moving direction of the headstock is the Z-axis direction and the moving direction of the grinding wheel head is the X-axis direction orthogonal to the Z-axis direction, the first calculation step is the plate as the first positional relationship. A distance in the X-axis direction between a reference point and the control turning center point is calculated, and the second calculation step includes the Z-axis between the plate reference point and the control turning center point as a second positional relationship. The distance in the direction is calculated, and the third calculation step calculates the distance in the X-axis direction and the Z-axis direction between the plate reference point and the control turning center point as the third positional relationship. In the process, the distance between the plate reference point and the control turning center point in the X-axis direction and the Z-axis direction may be calculated as a fourth positional relationship.

  (Claim 4) In the first calculation step, a first plate formed so that a cylindrical surface of the grinding wheel is parallel to the cylindrical surface in a state where the grinding wheel is positioned parallel to the Z-axis direction. A second plate reference formed so that an end surface of the grinding wheel is parallel to the end surface in a state where the grinding wheel is positioned in parallel with the Z-axis direction in contact with a reference surface. In the state where the grinding wheel is positioned at a turning angle position of +90 degrees to -90 degrees excluding 0 degrees and ± 90 degrees with respect to the X-axis direction. A cylindrical surface is brought into contact with a third plate reference surface formed so as to be parallel to the cylindrical surface, and the fourth calculation step is performed by removing the grinding wheel from 0 degrees and ± 90 degrees with respect to the X-axis direction. In a state where it is positioned at a turning angle position of -90 degrees from The end face of the grinding wheel may be brought into contact with the third plate reference surface formed so as to be parallel to the end face.

  (Claim 5) In the first calculation step, a first plate formed so that a cylindrical surface of the grinding wheel is parallel to the cylindrical surface in a state where the grinding wheel is positioned parallel to the Z-axis direction. A second plate reference formed so that an end surface of the grinding wheel is parallel to the end surface in a state where the grinding wheel is positioned in parallel with the Z-axis direction in contact with a reference surface. In the state where the grinding wheel is positioned at a turning angle position of +90 degrees to -90 degrees excluding 0 degrees and ± 90 degrees with respect to the X-axis direction. A cylindrical surface is brought into contact with a third plate reference surface formed so as to be parallel to the cylindrical surface, and the fourth calculation step is performed by removing the grinding wheel from 0 degrees and ± 90 degrees with respect to the X-axis direction. In a state where it is positioned at a turning angle position of -90 degrees from The cylindrical surface of the grinding wheel may be brought into contact with a fourth plate reference surface formed so as to be parallel to the cylindrical surface.

  (Claim 6) In the fourth calculation step, a fourth plate formed so that a cylindrical surface of the grinding wheel is parallel to the cylindrical surface in a state where the grinding wheel is positioned at the third turning angle position. You may make it contact a reference plane.

(Wheelstone turning center measuring device)
(Claim 7) The grinding wheel turning center measuring device of the present invention is capable of relative movement between a headstock and a grinding wheel base and turning of the grinding wheel base with respect to the headstock, and a workpiece mounted on the headstock is A grinding wheel turning center measuring device for measuring a position of an actual turning center point with respect to a position of the grinding wheel reference point of the grinding wheel in a grinding machine for grinding by a grinding wheel mounted on the grinding wheel table, and attached to the grinding wheel table Position measuring means capable of measuring the position, a plate reference point for measuring the position of the grinding wheel reference point of the grinding wheel, and a plurality of plate reference surfaces that contact the cylindrical surface or end surface of the grinding wheel The master plate and the cylindrical surface or end surface of the grinding wheel are brought into contact with the plate reference surface at different turning angles at least four times, and at least one plate reference surface is in contact with the other plate. A contact means for contacting a surface different from a cylindrical surface or an end surface of the grinding wheel that is in contact with a wheel reference surface, and a positional relationship between the plate reference point and a control turning center point by the contact step. The position of the grinding wheel reference point and the actual turning center point based on the calculating means for calculating, the positional relationship between the plate reference point and the plate reference surface, and the positional relationship between the plate reference point and the control turning center point Turning center calculating means for calculating the relationship.

  (Claim 1) The grinding wheel is positioned at the first, second, third, and fourth turning angle positions, and the positional relationship between the four plate reference points and the control turning center point is obtained. Then, the positional relationship between the grinding wheel reference point of the grinding wheel and the actual turning center point is calculated geometrically from the four positional relationships and the known dimensions of the master plate. According to this method, the position of the actual turning center point with respect to the position of the grinding wheel reference point of the grinding wheel can be measured with high accuracy. Therefore, for example, in the truing that forms the R shape of the grinding wheel by turning the grinding wheel base, the accuracy of the grinding wheel shape can be improved. Further, when grinding is performed with a grinding wheel by turning the grinding wheel base, the workpiece can be ground with high accuracy without correcting the dimensions for each turning angle of the grinding wheel base.

  (Claim 2) A pin capable of contacting the rotating grinding wheel is provided on the master plate so that the rotating grinding wheel does not have to be in direct contact with the master plate. As a result, it is not necessary to manually bring the stopped grinding wheel into direct contact with the master plate to obtain the positional relationship between the four plate reference points and the control turning center point, and the positional relationship is automatically obtained. It becomes possible.

  (Claim 3) The positional relationship between the Z-axis direction that is the movement direction of the headstock and the plate reference point in the X-axis direction that is orthogonal to the Z-axis direction that is the movement direction of the grinding wheel head and the turning center point on control. Looking for. Thereby, the positional relationship between the grinding wheel reference point of the grinding wheel and the actual turning center point can be easily calculated geometrically.

  (Claim 4) Since the first turning angle position and the second turning angle position are the same, the number of turning indexes of the grinding wheel can be reduced by one. Therefore, the cycle time of the grinding wheel turning center measurement can be shortened.

  (Claim 5) Since the turning angle in the third calculation step and the fourth calculation step can be reduced, the cycle time of the grinding wheel turning center measurement can be shortened. Further, it is possible to prevent interference between the grinding wheel and the truing device for truing the grinding wheel mounted on the head stock.

  (Claim 6) Since the turning angle positions of the grinding wheel in the third calculation step and the fourth calculation step are the same, the number of turning indexes of the grinding wheel can be reduced by one. Therefore, the cycle time of the grinding wheel turning center measurement can be shortened.

  (Embodiment 7) According to the grinding wheel turning center measuring device of the present invention, the same effects as those in the above-described grinding wheel turning center measuring method can be obtained. Further, other characteristic portions in the grinding wheel turning center measuring method can be similarly applied to the grinding wheel turning center measuring device of the present invention. And the same effect is produced.

It is a top view of a grinding machine. 1st embodiment: It is a top view of a master plate. 1st embodiment: It is a flowchart of a grindstone turning center measurement program. 1st embodiment: It is a figure which shows the procedure which calculates | requires the 1st positional relationship of a plate reference point and the turning center point on control. 1st embodiment: It is a figure which shows the procedure which calculates | requires the 2nd positional relationship of a plate reference point and the turning center point on control. 1st embodiment: It is a figure which shows the procedure which calculates | requires the 3rd positional relationship of a plate reference point and the turning center point on control. 1st embodiment: It is a figure which shows the procedure which calculates | requires the 4th positional relationship of a plate reference point and the turning center point on control. 1st embodiment: It is a figure which shows the positional relationship of the grindstone reference point of the grinding wheel 42, and an actual turning center point. 2nd embodiment: It is a top view of a master plate. 2nd embodiment: It is a figure which shows the method of calculating | requiring the 1st-4th positional relationship of a plate reference point and the turning center point on control. 3rd embodiment: It is a top view of a master plate. 3rd embodiment: It is a figure which shows the method of calculating | requiring the 1st-4th positional relationship of a plate reference point and the turning center point on control. 4th embodiment: It is a top view of a master plate. 4th embodiment: It is a figure which shows the method of calculating | requiring the 1st-4th positional relationship of a plate reference point and the turning center point on control. 5th embodiment: It is a top view of a master plate. 5th embodiment: It is a figure which shows the method of calculating | requiring the 1st-4th positional relationship of a plate reference point and the turning center point on control.

<First embodiment>
(1. Machine configuration of grinding machine)
As an example of the grinder 1, a grinder having a grindstone turning mechanism will be described as an example and described with reference to FIG. 1. As shown in FIG. 1, the grinding machine 1 is roughly composed of a bed 10, a headstock 20, a tailstock 30, a grinding wheel base 40, and a control device 50.

  The bed 10 has a substantially rectangular shape and is disposed on the floor. However, the shape of the bed 10 is not limited to a rectangular shape. A pair of headstock guide rails 11a and 11b are formed on the upper surface of the bed 10 so as to extend in the left-right direction (Z-axis direction) in FIG. The pair of spindle head guide rails 11a and 11b are rails on which a rectangular spindle head moving table 12 can slide.

  Further, the bed 10 is provided with a headstock Z-axis ball screw 11c between the pair of headstock guide rails 11a and 11b for driving the headstock movement table 12 in the left-right direction in FIG. A headstock Z-axis motor 11d for rotating the headstock Z-axis ball screw 11c is disposed. The headstock Z-axis motor 11d has an encoder 11e, and the encoder 11e can detect the rotation angle of the headstock Z-axis motor 11d.

  On the spindle table moving table 12, a spindle table 20 and a tailstock 30 are arranged to face each other. The head stock 20 includes a head stock main body 21, a chuck 22, and a main shaft motor 23. The headstock body 21 is fixed to the left side of FIG. 1 on the upper surface of the headstock moving table 12. A chuck 22 is provided on the headstock main body 21 so as to be rotatable around an axis parallel to the Z-axis direction. The rotating shaft member of the chuck 22 is connected to the motor shaft member of the main shaft motor 23 via a gear mechanism or the like.

  Although the details will be described later, in order to measure the position of the actual turning center point Cr with respect to the position of the grinding wheel reference point Pg of the grinding wheel 22, a substantially rectangular master plate 24 is provided on the grinding wheel head 40 side. Projected to As shown in FIG. 2, the master plate 24 has an angle of θ degrees (45 degrees in this example) in the range of 0 degrees to 90 degrees except for 0 degrees and 90 degrees with respect to the X-axis direction. It is formed in a shape that is cut out to form an inclined surface. The master plate 24 is provided with the apex of the left corner of the tip as a plate reference point P0.

  A plane parallel to the Z-axis direction from the plate reference point P0 to the boundary point P1 reaching the inclined surface is provided as the first plate reference surface SP1. An inclined surface from the boundary point P1 is provided as the third plate reference surface SP3. A surface parallel to the X-axis direction reaching the headstock body 21 from the boundary point P2 exceeding the inclined surface is provided as the second plate reference surface SP2.

  The master plate 24 is formed so that the inclination angle θ of the third plate reference plane SP3 and the distances A and B between the plate reference point P0 and the boundary points P1 and P2 have predetermined angles and dimensions. The master plate 24 is provided with first to third pins 25a to 25c that are perpendicular to the first to third plate reference planes SP1 to SP3 and can contact the rotating grinding wheel 42, respectively. Has been.

  The tailstock 30 includes a tailstock body 31 and a center 32. The tailstock body 31 is fixed to the right side of FIG. 1 on the upper surface of the head table moving table 12. The tailstock main body 31 is provided with a center 32 that is movable in the left-right direction. One end of the workpiece W is gripped by the chuck 22 and the other end is supported by the center 32, and is rotated around an axis parallel to the Z-axis direction by the spindle motor 23.

  On the upper surface of the bed 10, a pair of grindstone guide rails 13 a and 13 b are formed so as to extend in the vertical direction (X-axis direction) in FIG. 1 and in parallel with each other. The pair of grinding wheel head guide rails 13a and 13b are rails on which a rectangular grinding wheel head moving table 14 can slide. Further, the bed 10 is provided with a grinding wheel table X-axis ball screw 13c for driving the grinding wheel table moving table 14 in the vertical direction of FIG. 1 between the pair of grinding wheel table guide rails 13a and 13b. A grinding wheel base X-axis motor 13d for rotating the grinding wheel base X-axis ball screw 13c is disposed. The wheel head X-axis motor 13d has an encoder 13e, and the encoder 13e can detect the rotation angle of the wheel head X-axis motor 13d.

  On the grindstone table moving table 14, a circular grindstone table rotating table 15 that is rotatable about the B axis orthogonal to the X axis and the Z axis is arranged. A worm wheel 16 a for rotating the grinding wheel table rotary table 15 about the B axis is formed on the side edge of the grinding wheel table rotation table 15. A B-axis servomotor 16c in which a worm 16b meshing with the worm wheel 16a is fitted on the motor shaft is disposed on the grindstone table rotary table 15. The B-axis servomotor 16c has an encoder 16d, and the encoder 16d can detect the rotation angle of the B-axis servomotor 16c.

  A grindstone table 40 is disposed on the grindstone table 15. The grinding wheel base 40 includes a grinding wheel base main body 41, a grinding wheel 42, and a grinding wheel driving motor 43. A grinding wheel shaft member 44 is supported on the grinding wheel base body 41 so as to be rotatable about its axis. A grinding wheel 42 for grinding the workpiece W is attached to the tip of the grinding wheel shaft member 44. The rear end of the grinding wheel shaft member 44 is connected to the motor shaft member of the grinding wheel driving motor 43 via a belt transmission mechanism 45. That is, the grinding wheel 42 is rotationally driven around the axis of the grinding wheel shaft member 44 by the grinding wheel driving motor 43. Further, the grindstone base body 41 is provided with a touch sensor 46 as position measuring means. The touch probe 46a of the touch sensor 46 projects from the headstock 20 side. Instead of the touch sensor 46, the position may be measured by an ultrasonic (AE) sensor.

  The control device 50 mainly comprises a central processing unit 51, a memory 52 for storing various control values and programs, and interfaces 53 and 54. The memory 52 stores various data necessary for executing the grinding program and the grinding cycle. Various data is input to and output from the control device 50 via the interfaces 53 and 54. The input / output device 55 includes a keyboard for inputting data and the like, and a display device such as an LCD for displaying data. Further, a detection signal from the touch sensor 46 is input to the control device 50 via the amplifier 56.

  The control device 50 provides a drive signal to the headstock Z-axis motor 11 d that moves the headstock movement table 12 in the Z-axis direction via the Z-axis motor drive unit 57. The encoder 11e attached to the headstock Z-axis motor 11d sends the rotational position of the headstock Z-axis motor 11d, that is, the position of the headstock movement table 12 to the Z-axis motor drive unit 57 and the control device 50.

  Further, the control device 50 gives a drive signal to the grindstone table X-axis motor 13 d that moves the grindstone table moving table 14 in the X-axis direction via the X-axis motor drive unit 58. The encoder 13e attached to the wheel head X-axis motor 13d sends the rotational position of the wheel head X-axis motor 13d, that is, the position of the wheel head moving table 14 to the X-axis motor drive unit 58 and the control device 50.

  In addition, the control device 50 gives a drive signal to the B-axis servomotor 16 c that rotates the grinding wheel head rotary table 15 about the B-axis via the B-axis motor drive unit 59. The encoder 16d attached to the B-axis servomotor 16c sends the rotational position of the B-axis servomotor 16c, that is, the position of the grinding wheel base rotary table 15 to the B-axis motor drive unit 59 and the control device 50.

  The control device 50 drives the Z-axis motor 11d for the headstock and the X-axis motor 13d for the grindstone table based on the deviation between the target position command of the NC program stored in the memory 42 and the current position signal from the encoders 11e and 13e. Then, the workpiece W on the spindle table moving table 12 and the grinding wheel 42 on the wheel table moving table 14 are respectively positioned and controlled to target positions. Further, the B-axis servomotor 16c is driven by the deviation between the target position command and the current position signal from the encoder 16d, and the grinding wheel 42 on the grinding wheel table rotary table 15 is positioned (angle) at the target position (target angle). Control. Further, the control device 50 gives a drive signal to the spindle motor 23 and the grinding wheel driving motor 43 via a motor driving unit for the spindle motor 23 and a motor driving unit for the grinding wheel driving motor 43 (not shown).

(2. Grinding wheel turning center measurement process by control device)
Next, execution of the grinding wheel turning center measurement program by the control device 50 will be described with reference to FIGS. As shown in FIG. 1, the turning angle when the rotation axis Ag of the grinding wheel 42 is parallel to the Z-axis direction is 0 degree, and the clockwise direction is the positive direction.

  As shown in FIG. 3, the grindstone table 15 is rotated, and the grinding wheel 42 is positioned at a position where the turning angle is 0 degree as the first turning angle position (step S1). In this state, the wheel head moving table 14 and the head table moving table 12 are moved, and it is determined whether or not the cylindrical surface of the grinding wheel 42 has contacted the tip of the first pin 25a (step S2). As shown in FIGS. 4A to 4A, when the cylindrical surface of the grinding wheel 42 comes into contact with the tip of the first pin 25a, a position Xa in the X-axis direction with respect to the imaginary origin O of the contact point Qa is obtained ( Step S3).

  Then, the grindstone table 14 and the spindle table 12 are moved to bring the touch probe 46a of the touch sensor 46 into contact with the first plate reference surface SP1 as shown in FIGS. Then, the position Xb in the X-axis direction with respect to the aerial origin O of the first plate reference surface SP1 is measured. Further, as shown in FIGS. 4A to 4C, the touch probe 46a is brought into contact with the contact point Qa of the first pin 25a, and the position Xc of the contact point Qa with respect to the imaginary origin O is measured in the X-axis direction. (Step S4).

  4B, the obtained position Xa of the contact point Qa of the first pin 25a in the X-axis direction, the measured position Xb of the first plate reference surface SP1 in the X-axis direction, and the first pin Based on the position Xc in the X-axis direction of the contact point Qa at 25a, the position XA in the X-axis direction (= Xa− (Xc−Xb)) with respect to the aerial origin O of the plate reference point P0 is calculated. Then, a distance X1 (= Xcc−XA) in the X-axis direction is calculated as the first positional relationship between the plate reference point P0 and the control turning center point Cc (step S5). Xcc is a position in the X-axis direction with respect to the aerial origin O of the turning center point Cc for control.

  Next, the grinding wheel 42 is positioned at the second turning angle position. In this example, since the second turning angle position is the same as the first turning angle position, the turning angle of the grinding wheel 42 is 0. Whether or not the end face of the grinding wheel 42 is in contact with the tip of the second pin 25b while the wheel head moving table 14 and the spindle head moving table 12 are moved while being positioned at the position where the degree is reached (step S6). Judgment is made (step S7). As shown in FIGS. 5A to 5A, when the end face of the grinding wheel 42 comes into contact with the tip of the second pin 25b, the position Za in the Z-axis direction with respect to the aerial origin O of the contact point Qb is obtained (step) S8).

  Then, the grindstone table 14 and the spindle table 12 are moved to bring the touch probe 46a of the touch sensor 46 into contact with the second plate reference surface SP2 as shown in FIGS. Then, the position Zb in the Z-axis direction with respect to the aerial origin O of the second plate reference surface SP2 is measured. Further, as shown in FIGS. 5A to 5C, the touch probe 46a is brought into contact with the contact point Qb of the second pin 25b, and the position Zc of the contact point Qb with respect to the aerial origin O is measured. (Step S9).

  Then, as shown in FIG. 5B, the obtained position Za of the contact point Qb of the second pin 25b in the Z-axis direction, the measured position Zb of the second plate reference surface SP2 in the Z-axis direction, and the second pin Based on the position Zc of the contact point Qb of 25b in the Z-axis direction, the position ZA (= Za− (Zc−Zb) −B) of the plate reference point P0 with respect to the aerial origin O is calculated. Then, a distance Z3 (= Zcc−ZA) in the Z-axis direction is calculated as the second positional relationship between the plate reference point P0 and the turning center point Cc for control (step S10). Zcc is a position in the Z-axis direction with respect to the aerial origin O of the turning center point Cc in the control.

  Next, as shown in FIGS. 6A to 6A, the grinding wheel table rotary table 15 is rotated to position the grinding wheel 42 at a position where the turning angle is +45 degrees with the third turning angle position (step). S11). In this state, the wheel head moving table 14 and the head stock moving table 12 are moved to determine whether or not the cylindrical surface of the grinding wheel 42 has come into contact with the tip of the third pin 25c (step S12). When the cylindrical surface of the grinding wheel 42 contacts the tip of the third pin 25c, a position Xd in the X-axis direction and a position Zd in the Z-axis direction with respect to the aerial origin O of the contact point Qc are obtained (step S13).

  Then, the grindstone table 14 and the spindle table 12 are moved to bring the touch probe 46a of the touch sensor 46 into contact with the third plate reference surface SP3 as shown in FIGS. Then, the position Xe in the X-axis direction and the position Ze in the Z-axis direction with respect to the aerial origin O of the third plate reference surface SP3 are measured. Further, as shown in FIGS. 4A to 4C, the touch probe 46a is brought into contact with the contact point Qc of the third pin 25c, and the positions Xf and Z in the X-axis direction with respect to the aerial origin O of the contact point Qc The axial position Zf is measured (step S14).

  Then, as shown in FIG. 6B, the obtained position Xd of the contact point Qc of the third pin 25c and the position Zd in the Z-axis direction, and the measured third plate reference surface SP3 in the X-axis direction. Based on the position Xe and the position Ze in the Z-axis direction, the position Xf in the X-axis direction of the contact point Qc of the third pin 25c, and the position Zf in the Z-axis direction, the plate reference point P0 in the X-axis direction with respect to the imaginary origin O The position XB and the position ZB in the Z-axis direction are calculated. Then, a distance X2 (= Xcc-XB) in the X-axis direction and a distance Z2 (= Zcc-ZB) in the Z-axis direction are calculated as a third positional relationship between the plate reference point P0 and the turning center point Cc for control. (Step S15).

  Next, as shown in FIGS. 7A to 7A, the grinding wheel table rotary table 15 is rotated, and the grinding wheel 42 is positioned at a position where the turning angle becomes −45 degrees with the fourth turning angle position ( Step S16). In this state, the wheel head moving table 14 and the head stock moving table 12 are moved, and it is determined whether or not the end surface of the grinding wheel 42 has contacted the tip of the third pin 25c (step S17). When the end surface of the grinding wheel 42 contacts the tip of the third pin 25c, the position Xg in the X-axis direction and the position Zg in the Z-axis direction with respect to the aerial origin O of the contact point Qd are obtained (step S18).

  Then, the grindstone table 14 and the spindle table 12 are moved to bring the touch probe 46a of the touch sensor 46 into contact with the third plate reference surface SP3 as shown in FIGS. Then, a position Xh in the X-axis direction and a position Zh in the Z-axis direction with respect to the aerial origin O of the third plate reference surface SP3 are measured. Further, as shown in FIGS. 7A to 7C, the touch probe 46a is brought into contact with the contact point Qd of the third pin 25c, and the positions Xi and Z in the X-axis direction with respect to the aerial origin O of the contact point Qd The axial position Zi is measured (step S19).

  Then, as shown in FIG. 7B, the obtained X-axis position Xg and Z-axis position Zg of the contact point Qd of the third pin 25c, and the measured third plate reference surface SP3 in the X-axis direction. Based on the position Xh and the position Zh in the Z-axis direction, the position Xi in the X-axis direction of the contact point Qd of the third pin 25c, and the position Zi in the Z-axis direction, the plate reference point P0 in the X-axis direction with respect to the imaginary origin O The position XC and the position ZC in the Z-axis direction are calculated. Then, a distance X4 (= Xcc-XC) in the X-axis direction and a distance Z4 (= Zcc-ZC) in the Z-axis direction are calculated as the fourth positional relationship between the plate reference point P0 and the turning center point Cc for control. (Step S20). The positional relationship may be calculated by bringing the grinding wheel 42 into direct contact with the plate reference surfaces SP1 to SP3 manually without contacting the pins 25a to 25c.

  Then, as shown in FIG. 8, the distance X in the X-axis direction and the distance Z in the Z-axis direction are calculated as the positional relationship between the grinding wheel reference point of the grinding wheel 42 and the actual turning center point (step S21). Here, X1, Z3, X2, Z2, X4, and Z4 obtained from the first to fourth positional relationships are the distances in the X-axis direction between the control turning center point Cc and the actual turning center point Cr. When the distance in the Z-axis direction is Zo, it is expressed by the following equations (1) to (4). Therefore, by eliminating Xo and Zo from the equations (1) to (4), X and Z can be obtained from the following equations (5) and (6).

X1 = Xo + X (1)
X2 = Xo + (Xsinθ−Zcosθ)
− (Z2−Zo− (Xcos θ + Zsin θ) −A) / tan θ (2)
Z3 = Zo + Z + B (3)
Z4 = Zo + (− Xsinθ + Zcosθ)
+ (Xo + Xcos θ + Zsin θ−X4) * tan θ + A (4)

X = (− ((X1−X2) * tan θ− (Z2−Z3 + B−A))
* (1-1 / cos θ)-(Z4-Z3 + BA) + (X1-X4) * tan θ)
/ (Tan θ− (1-1 / sin θ) * (1-1 / cos θ) * tan θ) (5)
Z = ((((Z4−Z3 + BA)) / tan θ− (X1−X4)) * (1-1 / sin θ)
+ (X1-X2)-(Z2-Z3 + BA) / tan θ)
/ (1 / tan θ− (1-1 / cos θ) * (1-1 / sin θ) / tan θ) (6)

(3. Effect of grinding wheel turning center measurement process)
The grinding wheel 42 is positioned at the first, second, third, and fourth turning angle positions, and the positional relationship between the four plate reference points P0 and the turning center point Cc for control is obtained. From the four positional relationships and the known dimensions of the master plate 24, the positional relationship between the grinding wheel reference point Pg of the grinding wheel 42 and the actual turning center point Cr is calculated geometrically. According to this method, the position of the actual turning center point with respect to the position of the grinding wheel reference point of the grinding wheel can be measured with high accuracy. Therefore, for example, in truing that forms the R shape of the grinding wheel 42 by turning the grinding wheel base 40, the accuracy of the grinding wheel shape can be improved. Further, when grinding is performed by the grinding wheel 42 by turning the grinding wheel base 40, the workpiece W can be ground with high accuracy without correcting the dimensions for each turning angle of the grinding wheel base 40.

  Further, pins 25 a to 25 c with which the rotating grinding wheel 42 can come into contact are provided on the master plate 24 so that the rotating grinding wheel 42 does not have to be in direct contact with the master plate 24. Thus, it is not necessary to manually bring the stopped grinding wheel 42 into direct contact with the master plate 24 to obtain the positional relationship between the four plate reference points P0 and the control turning center point Cc. It can be obtained automatically. Further, the positional relationship between the plate reference point P0 in the Z-axis direction that is the movement direction of the headstock 20 and the X-axis direction that is orthogonal to the Z-axis direction that is the movement direction of the grindstone table 40 and the turning center point Cc on control. Looking for. Thereby, the positional relationship between the grinding wheel reference point Pg of the grinding wheel 42 and the actual turning center point Cr can be easily calculated geometrically. Moreover, since the 1st turning angle position and the 2nd turning angle position are the same, the frequency | count of turning index of the grinding wheel 42 can be decreased once. Therefore, the cycle time of the grinding wheel turning center measurement can be shortened.

<Second embodiment>
(1. Master plate configuration)
In this embodiment, a master plate 64 shown in FIG. 9 is used instead of the master plate 24 shown in FIG. As shown in FIG. 9, the master plate 64 is notched so that the right corner of the tip is an inclined surface having an angle of 0 degrees in the range of 0 degrees to 90 degrees excluding 0 degrees and 90 degrees with respect to the X-axis direction. And the left corner of the tip is notched so as to be an inclined surface with an angle of γ degrees in the range of 0 degrees to 90 degrees excluding 0 degrees and 90 degrees with respect to the X-axis direction. Yes. The master plate 64 has a boundary point between the inclined surface at the left end of the tip and a surface parallel to the Z-axis direction (first plate reference surface SP1a) as a plate reference point P0a.

  A plane parallel to the Z-axis direction from the plate reference point P0a to the boundary point P1a reaching the inclined surface at the right corner of the tip is provided as the first plate reference surface SP1a. An inclined surface at the right corner of the tip from the boundary point P1a is provided as the third plate reference surface SP3a. A plane parallel to the X-axis direction that reaches the headstock body 21 from the boundary point P2a that exceeds the inclined surface at the right corner of the tip is provided as the second plate reference plane SP2a. Further, an inclined surface at the left corner of the tip from the plate reference point P0a is provided as a fourth plate reference surface SP4a.

  The master plate 64 has an inclination angle θ of the third plate reference surface SP3a, an inclination angle γ of the fourth plate reference surface SP4a, and distances A and B between the plate reference point P0a and each of the boundary points P1a and P2a. It is created to be a dimension. The master plate 24 is provided with first to fourth pins (not shown) that are perpendicular to the first to fourth plate reference surfaces SP1a to SP4a and that can contact the rotating grinding wheel 42, respectively. Has been.

(2. Grinding wheel turning center measurement process by control device)
Also in this embodiment, the grindstone turning center measurement program is executed by the control device 50 shown in FIG. Then, the contact aspect of the grinding wheel 42 and the master plate 64 for calculating | requiring the 1st-4th positional relationship of the plate reference point P0a and the turning center point Cc on control is demonstrated with reference to FIG.

  As shown in FIG. 10A, the grinding wheel 42 is positioned as a first turning angle position at a position where the turning angle is 0 degree. In this state, the first positional relationship between the plate reference point P0a and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the first plate reference surface SP1a is obtained.

  Next, as shown in FIG. 10B, the grinding wheel 42 is positioned at the second turning angle position. In this example, the second turning angle position is the same as the first turning angle position. Therefore, the grinding wheel 42 is kept positioned at a position where the turning angle becomes 0 degree. In this state, the second positional relationship between the plate reference point P0a and the control turning center point Cc when the end surface of the grinding wheel 42 is brought into contact with the second plate reference surface SP2a is obtained.

  Next, as shown in FIG. 10C, the grinding wheel 42 is positioned at a position where the turning angle becomes 90-θ degrees with the third turning angle position. In this state, the third positional relationship between the plate reference point P0a and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the third plate reference surface SP3a is obtained.

  Next, as shown in FIG. 10 (D), the grinding wheel 42 is positioned at a position where the turning angle is 90 degrees-γ degrees with the fourth turning angle position. In this state, the fourth positional relationship between the plate reference point P0a and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the fourth plate reference surface SP4a is obtained. The relationship between the distance X5 in the X-axis direction between the plate reference point P0a and the controlled turning center point Cc and the distance Z5 in the Z-axis direction is expressed by the following equation (7).

Z5 = Zo + (− Xcosγ + Zsinγ) − (Xo + Xsinγ + Zcosγ−X5) * tanγ (7)

  And from the formulas (1) to (3) excluding the formula (4) used in the first embodiment and the following formulas (8) and (9), the grinding wheel reference point of the grinding wheel 42 and the actual turning center point As the positional relationship, a distance X in the X-axis direction and a distance Z in the Z-axis direction are calculated.

X = ((Z5−Z3 + B + (X1−X5) * tanγ) / tanθ + (X1−X2)
− (Z2−Z3 + B−A) / tan θ)
/ ((1-1 / sin θ) − (1 / cos γ−tan γ) / tan θ) (8)
Z = −X * (1 / cos γ−tan γ) − (Z5−Z3 + B + (X1−X5) * tan γ
... (9)

(3. Effect of grinding wheel turning center measurement process)
The positional relationship between the two plate reference points P0a and the control turning center point Cc can be obtained without greatly turning the grinding wheel 42. Therefore, the cycle time of the grinding wheel turning center measurement can be shortened. The master plate 64 has two inclined surfaces, a third plate reference surface SP3a and a fourth plate reference surface SP4a. For this reason, the grinding wheel 42 may be brought into contact with the two inclined surfaces, respectively, and interference between the grinding wheel 42 and other members such as a truing device and a pin for truing the grinding wheel 42 mounted on the headstock 20 hardly occurs. .

<Third embodiment>
(1. Master plate configuration)
In this embodiment, a master plate 64 shown in FIG. 11 is used instead of the master plate 24 shown in FIG. As shown in FIG. 11, the master plate 64 is notched so that the right corner of the tip is an inclined surface with an angle of 0 degrees in the range of 0 degrees to 90 degrees excluding 0 degrees and 90 degrees with respect to the X-axis direction. In addition, the left corner of the tip is an inclined surface having an angle of γ degrees (90 degrees-θ degrees in this example) in the range of 0 degrees to 90 degrees excluding 0 degrees and 90 degrees with respect to the X-axis direction. It is formed in the shape cut out like this. The master plate 64 has a boundary point between the inclined surface at the left end of the tip and a surface parallel to the Z-axis direction (first plate reference surface SP1b) as a plate reference point P0b.

  A plane parallel to the Z-axis direction from the plate reference point P0b to the boundary point P1b reaching the inclined surface at the right corner of the tip is provided as the first plate reference surface SP1b. An inclined surface at the right corner of the tip from the boundary point P1b is provided as the third plate reference surface SP3b. A plane parallel to the X-axis direction that reaches the headstock body 21 from the boundary point P2b that exceeds the inclined surface at the right corner of the tip is provided as the second plate reference plane SP2b. Further, an inclined surface at the left corner of the tip from the plate reference point P0b is provided as a fourth plate reference surface SP4b.

  The master plate 64 has an inclination angle θ of the third plate reference surface SP3b, an inclination angle γ of the fourth plate reference surface SP4b, and distances A and B between the plate reference point P0b and each of the boundary points P1b and P2b. It is created to be a dimension. The master plate 24 has first to fourth pins (not shown) that are perpendicular to the first to fourth plate reference planes SP1b to SP4b and that can contact the rotating grinding wheel 42, respectively. Has been.

(2. Grinding wheel turning center measurement process by control device)
Also in this embodiment, the grindstone turning center measurement program is executed by the control device 50 shown in FIG. Then, the contact aspect of the grinding wheel 42 and the master plate 64 for calculating | requiring the 1st-4th positional relationship of plate reference point P0b and the turning center point Cc on control is demonstrated with reference to FIG.

  As shown in FIG. 12A, the grinding wheel 42 is positioned at a position where the turning angle becomes 0 degree with the first turning angle position. In this state, the first positional relationship between the plate reference point P0b and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the first plate reference surface SP1b is obtained.

  Next, as shown in FIG. 12B, the grinding wheel 42 is positioned at the second turning angle position. In this example, the second turning angle position is the same as the first turning angle position. Therefore, the grinding wheel 42 is kept positioned at a position where the turning angle becomes 0 degree. In this state, the second positional relationship between the plate reference point P0b and the control turning center point Cc when the end surface of the grinding wheel 42 is brought into contact with the second plate reference surface SP2b is obtained.

  Next, as shown in FIG. 12C, the grinding wheel 42 is positioned at a position where the turning angle becomes −θ degrees with the third turning angle position. In this state, a third positional relationship between the plate reference point P0b and the control turning center point Cc when the end surface of the grinding wheel 42 is brought into contact with the third plate reference surface SP3b is obtained.

  Next, as shown in FIG. 12D, the grinding wheel 42 is positioned at the fourth turning angle position. In this example, the fourth turning angle position is the same as the third turning angle position. Therefore, the grinding wheel 42 is kept positioned at a position where the turning angle is −θ degrees (= − (90 degrees−γ degrees)). In this state, a fourth positional relationship between the plate reference point P0b and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the fourth plate reference surface SP4b is obtained. The plate reference point P0b, the distance A between the plate reference point P0b and the boundary point P1b, the inclination angle θ of the third plate reference surface SP3b, the inclination angle γ of the fourth plate reference surface SP4b, and the plate reference point P0b Based on the first to fourth positional relationships with the turning center point Cc, the X-axis direction distance X and the Z-axis direction distance Z are calculated as the positional relationship between the grinding wheel reference point of the grinding wheel 42 and the actual turning center point. To do.

(3. Effect of grinding wheel turning center measurement process)
Since the third turning angle position and the fourth turning angle position are the same, the number of turning indexes of the grinding wheel 42 can be reduced by one. Therefore, the cycle time of the grinding wheel turning center measurement can be shortened.

<Fourth embodiment>
(1. Master plate configuration)
In the present embodiment, a master plate 74 shown in FIG. 13 is used instead of the master plate 24 shown in FIG. As shown in FIG. 13, the master plate 74 has an angle of θc degrees (45 degrees in this example) in the range of 0 degrees to 90 degrees except for 0 degrees and 90 degrees with respect to the X-axis direction. It is formed in a shape that is cut out to form an inclined surface. The master plate 74 has a top left corner apex as a plate reference point P0c.

  A plane parallel to the Z-axis direction from the plate reference point P0c to the boundary point P1c reaching the inclined surface at the right corner of the tip is provided as the first plate reference surface SP1c. An inclined surface at the right corner of the tip from the boundary point P1c is provided as the second plate reference surface SP2c. The master plate 74 is formed such that the inclination angle θc of the second plate reference surface SP2c and the distance A between the plate reference point P0c and the boundary point P1c have a predetermined angle and size. The master plate 74 is provided with first and second pins (not shown) that are perpendicular to the first and second plate reference planes SP1c and SP2c and that can contact the rotating grinding wheel 42, respectively. Has been.

(2. Grinding wheel turning center measurement process by control device)
Also in this embodiment, the grindstone turning center measurement program is executed by the control device 50 shown in FIG. Then, the contact aspect of the grinding wheel 42 and the master plate 74 for calculating | requiring the 1st-4th positional relationship of the plate reference point P0c and the turning center point Cc on control is demonstrated with reference to FIG.

  As shown in FIG. 14A, the grinding wheel 42 is positioned as a first turning angle position at a position where the turning angle is 0 degree. In this state, a first positional relationship between the plate reference point P0c and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the first plate reference surface SP1c is obtained.

  Next, as shown in FIG. 14B, the grinding wheel 42 is positioned at a position where the turning angle becomes −90 degrees as the second turning angle position. In this state, the second positional relationship between the plate reference point P0c and the control turning center point Cc when the end surface of the grinding wheel 42 is brought into contact with the first plate reference surface SP1c is obtained.

  Next, as shown in FIG. 14C, the grinding wheel 42 is positioned at a position where the turning angle becomes + θ degrees (45 degrees) with the third turning angle position. In this state, the third positional relationship between the plate reference point P0c and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the second plate reference surface SP2c is obtained.

  Next, as shown in FIG. 14D, the grinding wheel 42 is positioned at a position where the turning angle becomes −θ degrees (−45 degrees) with the fourth turning angle position. In this state, a fourth positional relationship between the plate reference point P0c and the control turning center point Cc when the end surface of the grinding wheel 42 is brought into contact with the second plate reference surface SP2c is obtained.

  The plate reference point P0c, the distance A between the plate reference point P0c and the boundary point P1c, the inclination angle θc of the second plate reference surface SP2c, and the first to fourth of the plate reference point P0c and the control turning center point Cc. Based on the positional relationship, the distance X in the X-axis direction and the distance Z in the Z-axis direction are calculated as the positional relationship between the grinding wheel reference point of the grinding wheel 42 and the actual turning center point.

(3. Effect of grinding wheel turning center measurement process)
On the master plate 74, only two plate reference surfaces SP1b and SP2b and two pins are formed. Thereby, the manufacturing cost of the master plate 84 can be reduced.

<Fifth embodiment>
(1. Master plate configuration)
In the present embodiment, a master plate 84 shown in FIG. 15 is used instead of the master plate 24 shown in FIG. The master plate 84 is formed in a rectangular shape as shown in FIG. The master plate 84 is provided with the apex of the left end of the tip as the plate reference point P0d.

  A surface parallel to the Z-axis direction from the plate reference point P0d to the apex P1d at the right corner of the tip is provided as the first plate reference surface SP1d. A surface parallel to the X-axis direction reaching the headstock main body 21 from the apex P1d at the tip right corner is provided as the second plate reference surface SP2d. The master plate 84 is created such that the distance B between the plate reference point P0d and the apex P1d of the tip right corner is a predetermined angle and size. The master plate 84 is provided with first and second pins (not shown) that are perpendicular to the first and second plate reference surfaces SP1d and SP2d and that can contact the rotating grinding wheel 42, respectively. Has been.

(2. Grinding wheel turning center measurement process by control device)
Also in this embodiment, the grindstone turning center measurement program is executed by the control device 50 shown in FIG. Then, the contact aspect of the grinding wheel 42 and the master plate 84 for calculating | requiring the 1st-4th positional relationship of plate reference point P0d and the turning center point Cc on control is demonstrated with reference to FIG.

  As shown in FIG. 16 (A), the grinding wheel 42 is positioned at a position where the turning angle becomes 0 degree as the first turning angle position. In this state, the first positional relationship between the plate reference point P0d and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the first plate reference surface SP1d is obtained.

  Next, as shown in FIG. 16B, the grinding wheel 42 is positioned at the second turning angle position. In this example, the second turning angle position is the same as the first turning angle position. Therefore, the grinding wheel 42 is kept positioned at a position where the turning angle becomes 0 degree. In this state, the second positional relationship between the plate reference point P0d and the control turning center point Cc when the end surface of the grinding wheel 42 is brought into contact with the second plate reference surface SP2d is obtained.

  Next, as shown in FIG. 16C, the grinding wheel 42 is positioned at a position where the turning angle becomes −90 degrees as the third turning angle position. In this state, a third positional relationship between the plate reference point P0d and the control turning center point Cc when the end surface of the grinding wheel 42 is brought into contact with the first plate reference surface SP1d is obtained.

  Next, as shown in FIG. 16D, the grinding wheel 42 is positioned at the fourth turning angle position. In this example, the fourth turning angle position is the same as the third turning angle position. Therefore, the grinding wheel 42 is kept positioned at a position where the turning angle becomes −90 degrees. In this state, a fourth positional relationship between the plate reference point P0d and the control turning center point Cc when the cylindrical surface of the grinding wheel 42 is brought into contact with the second plate reference surface SP2d is obtained.

  Then, based on the plate reference point P0d, the distance B between the plate reference point P0d and the apex P1d at the tip right corner, and the first to fourth positional relationships between the plate reference point P0d and the control turning center point Cc, The distance X in the X-axis direction and the distance Z in the Z-axis direction are calculated as the positional relationship between the grinding wheel reference point of the vehicle 42 and the actual turning center point.

(3. Effect of grinding wheel turning center measurement process)
On the master plate 84, only two plate reference planes SPd1, SPd2 and two pins orthogonal to each other are formed. Thus, the positional relationship between the four plate reference points and the control turning center point can be obtained only by turning the grinding wheel 42 90 degrees once. Therefore, the cycle time of the grinding wheel turning center measurement can be further shortened.

<Deformation of each embodiment>
In the first embodiment, the third and fourth calculation steps are configured such that the cylindrical surface and the end surface of the grinding wheel 42 are in contact with the third plate reference surface SP3, respectively. The three plate reference surface SP3 may be brought into contact with each other. In the second embodiment, the third and fourth calculation steps are configured such that the cylindrical surface and the end surface of the grinding wheel 42 are in contact with the third plate reference surface SP3a and the fourth plate reference surface SP4a, respectively. The end surface and the cylindrical surface may be in contact with the third plate reference surface SP3a and the fourth plate reference surface SP4a, respectively.

  In each embodiment, at the time of initial setting when the grinding machine 1 is started up, the distance between the grinding wheel reference point Pg and the control turning center point Cc is obtained using a master grinding wheel whose dimensions are known. Then, the distance between the reference position for mounting the grinding wheel 42 and the turning center point Cc for control is obtained by dividing the dimension of the master grinding wheel from the obtained distance. Then, after exchanging the grindstone, the distance between the grindstone reference point Pg and the actual turning center point Cr may be obtained only by positioning at the reference angle.

1: Grinding machine 10: bed, 11a, 11b: guide rail for headstock
12: moving table for spindle head, 13a, 13b: guide rail for grinding wheel base 14: moving table for grinding wheel base 11c: Z axis ball screw for grinding wheel base, 11d: Z axis motor for grinding wheel base 20: spindle head, 21: spindle Base body 22: Chuck 23: Spindle motor 24, 64, 74, 84: Master plate 25a-25c: First to third pins 30: Tailstock 31: Tailstock body 32: Center 40: Grinding wheel base, 41: Grinding wheel main body, 42: Grinding wheel, 43: Grinding wheel drive motor 46: Touch sensor, 46a: Touch probe 50: Control device

Claims (7)

A grinding machine capable of relative movement between a headstock and a wheelhead and turning of the wheelhead relative to the headstock, and grinding a workpiece mounted on the headstock by a grinding wheel mounted on the wheelhead. A master plate having a plate reference point for measuring the position of the grinding wheel reference point of the grinding wheel and a plurality of plate reference surfaces that contact the cylindrical surface or end surface of the grinding wheel, and the grinding wheel of the grinding wheel In the grinding wheel turning center measuring method for measuring the actual turning center position relative to the reference point position,
A cylindrical surface or an end surface of the grinding wheel is brought into contact with the plate reference surface at least four times at different turning angles, and at least one plate reference surface is brought into contact with another plate reference surface. A contact step of contacting a surface different from the cylindrical surface or the end surface;
A calculation step of calculating a positional relationship between the plate reference point and a control turning center point by the contact step;
A turning center that calculates a positional relationship between the grinding wheel reference point and the actual turning center point from the positional relationship between the plate reference point and the plate reference plane and the positional relationship between the plate reference point and the turning center point on the control. A calculation process;
A grinding wheel turning center measuring method comprising: In claim 1,
The master plate is provided with a plurality of pins that are perpendicular to the plurality of plate reference planes and can contact the rotating grinding wheel, respectively.
A position measuring means capable of measuring a position is attached to the grindstone table,
In the abutting step, a cylindrical surface or an end surface of the grinding wheel is brought into contact with the pin at least four times at different turning angles, and at least one of the pins is brought into contact with the other pin. A step of contacting a surface different from a surface or an end surface to determine a position of a contact point between the grinding wheel and the pin, and a step of measuring the position of the plate reference surface and the position of the pin contact point by the position measuring means And
The calculation step is based on the position of the contact point between the grinding wheel and the pin, the position of the plate reference surface measured by the position measuring means, and the position of the contact point of the pin. A method for measuring a turning center of a grindstone, which is a step of calculating a positional relationship with the turning center of the wheel. In claim 1 or 2,
When the direction of movement of the headstock is the Z-axis direction and the direction of movement of the grinding wheel base is the X-axis direction orthogonal to the Z-axis direction,
The first calculation step calculates a distance in the X-axis direction between the plate reference point and the control turning center point as the first positional relationship,
The second calculation step calculates the distance in the Z-axis direction between the plate reference point and the control turning center point as the second positional relationship,
The third calculation step calculates the distance in the X-axis direction and the Z-axis direction between the plate reference point and the control turning center point as the third positional relationship,
A 4th calculating process is a grindstone turning center measuring method which calculates the distance of the X-axis direction and the Z-axis direction between the plate reference point and the control turning center point as a fourth positional relationship. In any one of Claims 1-3,
In the first calculation step, with the grinding wheel positioned in parallel with the Z-axis direction, the cylindrical surface of the grinding wheel is brought into contact with a first plate reference surface formed to be parallel to the cylindrical surface. ,
In the second calculation step, with the grinding wheel positioned in parallel with the Z-axis direction, the end surface of the grinding wheel is brought into contact with a second plate reference surface formed to be parallel to the end surface,
In the third calculation step, in the state where the grinding wheel is positioned at a turning angle position of +90 degrees to −90 degrees excluding 0 degrees and ± 90 degrees with respect to the X-axis direction, the cylindrical surface of the grinding wheel is A third plate reference surface formed so as to be parallel to the surface,
In the fourth calculation step, the grinding wheel is positioned at a turning angle position of +90 degrees to -90 degrees excluding 0 degrees and ± 90 degrees with respect to the X-axis direction, and the end face of the grinding wheel is A method for measuring a turning center of a grindstone that is brought into contact with a reference surface of the third plate formed to be parallel. In any one of Claims 1-3,
In the first calculation step, with the grinding wheel positioned in parallel with the Z-axis direction, the cylindrical surface of the grinding wheel is brought into contact with a first plate reference surface formed to be parallel to the cylindrical surface. ,
In the second calculation step, with the grinding wheel positioned in parallel with the Z-axis direction, the end surface of the grinding wheel is brought into contact with a second plate reference surface formed to be parallel to the end surface,
In the third calculation step, in the state where the grinding wheel is positioned at a turning angle position of +90 degrees to −90 degrees excluding 0 degrees and ± 90 degrees with respect to the X-axis direction, the cylindrical surface of the grinding wheel is A third plate reference surface formed so as to be parallel to the surface,
In the fourth operation step, the grinding wheel is positioned at a turning angle position of +90 degrees to −90 degrees excluding 0 degrees and ± 90 degrees with respect to the X-axis direction, and the cylindrical surface of the grinding wheel is A method for measuring a turning center of a grindstone that is brought into contact with a fourth plate reference surface formed to be parallel to the surface. In claim 5,
In the fourth calculation step, with the grinding wheel positioned at the third turning angle position, the cylindrical surface of the grinding wheel is brought into contact with a fourth plate reference surface formed to be parallel to the cylindrical surface. Measuring method for turning center of grinding wheel. In a grinding machine capable of relative movement between the headstock and the wheelhead and turning of the wheelhead relative to the headstock, and grinding a workpiece mounted on the headstock by a grinding wheel mounted on the wheelhead, A grinding wheel turning center measuring device for measuring the position of an actual turning center point with respect to the position of the grinding wheel reference point of the grinding wheel,
Position measuring means attached to the grinding wheel platform and capable of measuring the position;
A master plate having a plate reference point for measuring the position of the grinding wheel reference point of the grinding wheel and a plurality of plate reference surfaces that contact the cylindrical surface or the end surface of the grinding wheel;
A cylindrical surface or an end surface of the grinding wheel is brought into contact with the plate reference surface at least four times at different turning angles, and at least one plate reference surface is brought into contact with another plate reference surface. A contact means for contacting a surface different from the cylindrical surface or the end surface;
A calculating means for calculating a positional relationship between the plate reference point and a control turning center point by the contact step;
A turning center that calculates a positional relationship between the grinding wheel reference point and the actual turning center point from the positional relationship between the plate reference point and the plate reference plane and the positional relationship between the plate reference point and the turning center point on the control. Computing means;
A whetstone turning center measuring device.

Images