JP7595929B2 - How to correct the grinding surface of a grinding wheel - Google Patents

Description

The present invention relates to a method for modifying the grinding surface of a grinding wheel, which modifies (dresses or trues) the grinding surface on the outer periphery of a rotating grinding wheel. Here, dressing refers to sharpening the grinding surface, and truing refers to shaping the grinding surface. Dressing and truing are collectively referred to as modification.

Patent Document 1 discloses a method for correcting the grinding surface of a processing grindstone using a correcting grindstone (dressing grindstone). That is, in Patent Document 1, as shown in Figures 17(a) to (c), the grinding surface 102 on the outer periphery of the processing grindstone 101 is rotated and applied to the correcting surface 110 on the upper surface of the correcting grindstone 100, which is rotated around the axis α. The axis β of the processing grindstone 101 extends perpendicular to the axis α of the correcting grindstone 100. The processing grindstone 101 is then moved between the inner diameter side and the outer diameter side of the correcting surface 110 of the correcting grindstone 100, and correction (dressing) is performed.

Japanese Unexamined Patent Publication No. 64-27858

In the correction method of Patent Document 1, as shown in Figure 18, the correction surface 110 of the correction grindstone 100 and the grinding surface 102 of the processing grindstone 101 are worn unevenly in an inclined manner. This is because the peripheral speed of the correction surface 110 on the upper surface of the correction grindstone 100 becomes faster toward the outer diameter side, and the amount of material removed becomes greater toward the outer diameter side.

If the shape of the grinding surface 102 of the grinding wheel 101 is deformed in this way, it becomes difficult to perform grinding processing using the grinding wheel 101 with high precision.

In the present invention, a method for correcting a grinding surface of a grinding wheel is used, which is rotated around a first axis and has a correction surface located in a plane perpendicular to the first axis, and a grinding surface provided on the outer peripheral surface of a grinding wheel rotating around a second axis extending in a direction perpendicular to the first axis is brought into contact with the correction surface to correct the grinding surface. The grinding wheel is disposed so that, when viewed from a direction along the first axis, the second axis overlaps with the diameter of the rotation correction body and the center line passing through the center of the width direction of the grinding wheel overlaps with a chord other than the diameter of the rotation correction body, and the grinding surface is corrected at two different locations on the correction surface, and the relationship between one side and the other side in the width direction of the grinding wheel and the outer peripheral side and inner peripheral side of the portion of the correction surface where the grinding surface is brought into contact is reversed at the two locations .

The present invention is a method for correcting a grinding surface of a grinding wheel, which uses a pair of rotational correction bodies that are rotated in the same direction as each other about a first axis that is parallel to each other and each have a correction surface located in a plane perpendicular to the first axis, and which applies a grinding surface provided on the outer peripheral surface of a grinding wheel that rotates about a second axis that extends in a direction perpendicular to the first axis to the correction surface to correct the grinding surface, and is characterized in that the grinding wheel is disposed so that, when viewed from a direction along the first axis, the second axis overlaps with the diameters of both of the rotational correction bodies and the center line passing through the center of the grinding wheel in the width direction overlaps with a chord other than the diameter of the rotational correction body, and the grinding surface is corrected by the correction surfaces of the pair of rotational correction bodies , and the relationship between one side and the other side in the width direction of the grinding wheel and the outer peripheral side and inner peripheral side of the portion of the correction surface of the rotational correction body to which the grinding surface is applied is reversed on the correction surfaces of the pair of rotational correction bodies .

By using the above method, uneven wear does not occur on the grinding wheel, and the grinding surface can be modified to a cylindrical shape centered on its axis.

The present invention has the effect of being able to obtain a grinding wheel for machining that can achieve high-precision machining by modifying the grinding surface of the outer periphery of the grinding wheel into a cylindrical shape.

Front view of the grinding machine. Cross-sectional view of a grinding wheel. FIG. 2 is a perspective view of a correction device used in the first embodiment. FIG. FIG. 4 is a plan view showing a repaired state of the first embodiment. FIG. 11 is a perspective view of a correction device used in a second embodiment. FIG. FIG. 4 is a cross-sectional view showing a power transmission system for a correcting grindstone. FIG. 11 is a plan view showing a repaired state of the second embodiment. FIG. 2 is a block diagram showing the electrical configuration of the correction system. FIG. FIG. 11 is a side view showing a modified state of the modified example. FIG. 11 is a plan view showing a second modified example. FIG. 13 is a plan view showing a third modified example. FIG. 13 is a plan view showing a fourth modified example. FIG. 13 is a plan view showing a fifth modified example. 1A is a plan view, FIG. 1B is a cross-sectional view, and FIG. 1C is a front view showing a conventional repair method. 1 is a cross-sectional view showing the result of a conventional repair method.

First Embodiment
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will now be described with reference to the drawings.
As shown in Fig. 1 and Fig. 10, in this embodiment, the grinding machine 11 and the correction device 21 constitute a correction system 1. In this embodiment, dressing and truing, which indicate correction, are performed using the correction system 1. In this case, the processing mode is determined according to various conditions such as the hardness of the binder 105 of the grindstone 101, the hardness of the abrasive grains 106 of the correction grindstone 100, or the amount of cut for correction, which will be described later. That is, depending on the difference in these conditions, it is determined whether the processing mode is dressing, which is the sharpening of the abrasive grains 106, or truing, which is the shaping of the grinding surface 102 of the grindstone 101.

(Grinding machine 11)
As shown in Figures 1 and 10, a table 13 is supported on the upper surface of a bed 12 of a grinding machine 11 so as to be movable in the X-axis direction, which is the left-right direction, by an X-axis motor 131. A workpiece 200 is supported on the upper surface of this table 13. A column 14 is supported on the bed 12 so as to be movable in the Z-axis direction, which is the front-rear direction, by a Z-axis motor 141. A rotating shaft 16 is supported on this column 14 and rotated about an axis β extending in the Z-axis direction by a rotary drive motor 161. A processing grindstone 101 is fixedly supported on the rotating shaft 16. The processing grindstone 101 is moved together with the rotating shaft 16 in the Y-axis direction, which is the up-down direction, by a Y-axis motor 161.

As shown in FIG. 2, the grindstone 101 has an abrasive layer 104 integrated on the outer periphery of a disk-shaped main body 103. This abrasive layer 104 is formed by holding abrasive grains 106 with a metallic binder 105.

As shown in FIG. 10, the operation of each of the motors 131, 141, 151, and 161 of the grinding machine 11 is controlled by the control device 17 of the grinding machine 11. The operation unit 18, such as a keyboard, is manually operated to send control signals to the control device 17.

(Correction device 21)
The correction device 21 is placed on the table 13 .
As shown in Figures 1, 3 and 4, a correction grindstone 100, which is a rotating correction body consisting of a cup-shaped grindstone, is arranged on a shaft 24 in a casing 22 of the correction device 21. The axis (first axis) α of the shaft 24 extends in the Y-axis direction when the correction device 21 is placed on the table 13. In this state, the upper surface of the correction grindstone 100 forms a correction surface 110 located in a plane parallel to the X-axis and Z-axis directions. The correction grindstone 100 is rotated by a motor 25 shown in Figure 10. The operation of the motor 25, such as the rotation speed, is controlled by a control device 26. An operating unit 27, such as a control panel, is manually operated to output a control signal to the control device 26.

The correction device 21 has a magnet (not shown) on its bottom surface, and the correction device 21 is fixed to the top surface of the table 13 by the magnetic force of the magnet. The fixing position of the correction device 21 is arbitrary, and for example, a position on the rear side of the installation position of the workpiece 200 is selected.

(Operation of the First Embodiment)
Next, a method for correcting the ground surface 102 according to this embodiment will be described.
FIG. 5 shows the state of the grinding surface 102 of the grindstone 101 in a correction process.

When correcting the grinding surface 102, which is the outer peripheral surface of the grindstone 101, the grindstone 101 is placed at the first position 301. That is, in this state, when viewed from above in the direction of the axis α of the correction grindstone 100, the axis (second axis) β of the grindstone 101 is oriented in the radial direction of the correction surface 110 of the correction grindstone 100. As shown by the solid line in FIG. 5, this first position 301 is located on the rear end side of the correction grindstone 100 in the Z-axis direction. Therefore, the axis α and the axis β are perpendicular to each other and form a right angle. In this state, the grindstone 101 is rotated in one direction P, and the correction grindstone 100 is rotated in the same direction Q as the grindstone 101 at the first position 301. In this case, the same direction means that when the grinding surface 102 of the grinding wheel 101 and the correction surface 110 of the correction wheel 100 come into contact, their contact points move in approximately the same direction.

Also, in this case, initially, the grinding surface 102 of the processing grindstone 101 and the contact portion of the correction surface 110 of the correction grindstone 100 with the grinding surface 102 are rotated at the same speed. In this case, the motor drive of the correction grindstone 100 is only required at the beginning, as described above. Then, when the motor drive is stopped, the correction grindstone 100 rotates following the processing grindstone 101 through contact with the processing grindstone 101. Then, the processing grindstone 101 is moved back and forth an appropriate number of times in the Z-axis direction, as shown by the solid line and the two-dot chain line. In this case, a peeling force is generated against the grinding surface 102 due to the movement of the grinding surface 102 in the Z-axis direction. This peeling force corrects the grinding surface 102. Furthermore, when the correction grindstone 100 is in a follow-up rotation state, a speed difference occurs between the correction surface 110 and the grinding surface 102 in the portion away from the center line γ in the width direction of the grinding surface 102. This speed difference increases as the distance from the center line γ increases. This speed difference generates a peeling force in the torsional direction on the grinding surface 102. Therefore, the grinding surface 102 is also corrected by this peeling force.

Next, the grindstone 101 is moved along the Z axis to the second position 302 on the opposite side, 180 degrees away from the first position 301 on the correction surface of the correction grindstone 100, with the axis β located on the Z axis. In this case, at the beginning of correction when the grindstone 100 is moved to the second position 302, the rotation direction of the correction grindstone 100 is switched to the opposite direction R, which is the rotation direction of the grindstone 101, by the motor drive. In this case, as in the above, the rotation speed of the contact part is set to the same speed at the beginning of contact between the grindstone 101 and the correction grindstone 100. Thereafter, the motor drive of the correction grindstone 100 is stopped. Then, at the second position 302 on the correction surface, the grindstone 101 is rotated and reciprocated in the Z axis direction in the same way. Therefore, at the second position 302, the same correction as at the first position 301 is performed. Note that if the amount of correction of the grinding surface 102 is small, the movement in the Z axis direction at the first position and the second position does not have to be a reciprocating movement. Furthermore, if the movement direction of the grinding surface 102 is the opposite direction to that shown in FIG. 5, the rotation directions Q and R of the correction grindstone 100 will also be the opposite directions to that shown in FIG. 5.

Both the correcting grindstone 100 and the processing grindstone 101 may be continuously driven by a motor. In this case, it is preferable that the speed difference between the two is not so large.
In this way, the positional relationship of the correction surface 110 with respect to the grinding surface 102 is reversed at the first position 301 and the second position 302. Therefore, even if uneven wear due to inclination occurs on the grinding surface 102 during correction at the first position 301, the uneven wear is corrected during correction at the second position 302. Therefore, the grinding surface 102 is corrected (dressed or trued) so as to become a highly accurate cylindrical surface centered on the axis β.

(Effects of the First Embodiment)
This embodiment has the following advantages.
(1) The grinding surface 102 of the grindstone 101 can be modified to a cylindrical surface centered on the axis β, thereby preventing uneven wear. As a result, the grinding process of the workpiece 200 using the grindstone 101 can be performed with high accuracy.

(2) The correction grindstone 100 can be used to perform corrections such as truing and dressing of the grinding surface 102 of the processing grindstone 101. Therefore, unlike conventional grinding devices, there is no need for a device dedicated to truing or dressing.

(3) Correction such as dressing is performed over a wide area on the correction surface 110 of the rotating correction grindstone 100. This makes it possible to perform dressing efficiently in a short time compared to pinpoint dressing using a single sharp-pointed dresser.

(4) When truing and dressing are performed consecutively, both operations can be performed in the same position, compared to a grinding machine in which the truing device and the dressing device are separately installed. This reduces the time lag between the two operations, allowing for efficient consecutive operations.

(5) The grinding surface 102 of the grinding wheel 101 is corrected by being twisted and pulled off. Therefore, even if the abrasive grain binder 105 of the grinding wheel 101 is made of a high hardness material such as metal, the grinding surface 102 can be corrected efficiently and with high precision.

(6) At the beginning of rotation of the correction grindstone 100, the motor is driven so that the correction grindstone 100 rotates at approximately the same speed as the processing grindstone 101, and then the motor drive is stopped. Therefore, the correction grindstone 100 rotates following the rotation of the processing grindstone 101. Therefore, when the rotation speed of the correction grindstone 100 is configured to be inverter controlled, malfunctions in the inverter can be prevented in advance.

Second Embodiment
Next, a second embodiment of the present invention will be described. In the second embodiment and the modified example, the following description will focus on the differences from the first embodiment.

In this embodiment, a pair of correction grindstones 100 are arranged. That is, as shown in Figs. 6 to 8, a pair of correction grindstones 100 rotated by one motor 25 are provided in the casing 22. A pulley 30 is provided on the shaft 261 of the motor 25 and the shaft 24 of the correction grindstone 100. An idle pulley 32 is provided on the casing 22 by a shaft 33. As shown in Figs. 7 and 8, a belt 31 as a circular cord is hung from the pulley 30 of the motor 25 to the pulleys 30 and the idle pulleys 32 of both correction grindstones 100. Therefore, the correction grindstones 100 rotate in the opposite directions. In this configuration, the pair of correction grindstones 100 are arranged close to each other. It is preferable that the proximity interval is narrow as long as the correction grindstones 100 do not contact each other, and it is preferable that the proximity interval is narrower than the width of the processing grindstone 101. The axis α of both correction grindstones 100 is arranged on the Z-axis line.

(Function of the Second Embodiment)
Next, the operation of the second embodiment will be described.
In this embodiment, a first position 301 for performing the correcting operation is set at an end of one of the correcting grindstones 100 in the Z-axis direction on the side of the other correcting grindstone 100. A second position 302 is set at a position close to the first position 301 of the other correcting grindstone 100. In other words, the first position 301 and the second position 302 are located on the axis α of both correcting surfaces 110, and are located on opposite sides of the correcting surface 110 at two positions between both axis α.

As shown in FIG. 9, when correcting the grinding surface 102 of the processing grindstone 101, both correction grindstones 100 are rotated at the first position 301 and the second position 302 so that the rotation direction of the processing grindstone 101 is the same. In this state, the processing grindstone 101 is reciprocated in the radial direction of the correction grindstone 100 at the first position 301 and the second position 302 on the Z-axis line passing through the axis β. If the amount of correction is small, there is no need to reciprocate. In this way, the grinding surface 102 of the processing grindstone 101 can be corrected in the same way as in the above embodiment. In other words, since the outer diameter side of the correction surface 110 of both correction grindstones 100 is located on the opposite side in the width direction of the grinding surface 102, uneven wear of the grinding surface 102 can be prevented.

Even in this case, if both correction grindstones 100 are motor-driven at the beginning of correction and then the motor drive is stopped, the correction grindstones 100 will rotate in a follow-up manner. The drive rotation and follow-up rotation of one correction grindstone 100 are then transmitted to the other correction grindstone 100 via the belt 31. This allows both correction grindstones 100 to rotate simultaneously at the same speed.

(Effects of the Second Embodiment)
In addition to the effects of the first embodiment, the second embodiment has the following effects.
(7) Since the pair of correcting grindstones 100 are rotated in opposite directions at the first and second positions 301, 302 simultaneously, there is no need to switch the rotation direction of the correcting grindstones 100 when moving the processing grindstone 101 between the first and second positions 301, 302. Therefore, the correcting work can be carried out efficiently in a short time.

(8) Because the distance between the outer circumferences of the two correction grindstones 100 at the closest points is narrower than the width of the processing grindstone 101, even if the processing grindstone 101 is positioned between the correction grindstones 100, it continues to be in contact with at least one of the correction grindstones 100. Moreover, both correction grindstones 100 are rotated integrally via the belt 31. Therefore, even if the motor drive of the correction grindstones 100 is stopped, the processing grindstone 101 smoothly transitions from one rotating correction grindstone 100 to the other correction grindstone 100 rotating at the same speed.

(Example of change)
The above-described embodiments may be modified as follows. The embodiments and the following modifications may be combined with each other to the extent that no technical contradiction occurs.

11 and 12, in the configuration of the first embodiment, the processing grindstone 101 is arranged so that its center line γ is located on the radial line of the correction surface 110 passing through the axis α of the correction grindstone 100. Then, as shown in FIG. 12, the processing grindstone 101 is moved back and forth along the radial line as shown by the solid line and the two-dot chain line. In this case, the rotation direction of the correction grindstone 100 is not switched and the processing grindstone 101 is continuously rotated in the Q direction or the R direction. In this case, as shown by the solid line and the two-dot chain line in FIG. 13 , the processing grindstone 101 may be moved across the axis α. Furthermore, in this case, the motor drive of the correction grindstone 100 is continued without stopping, and it is not necessarily required to switch the rotation direction. This method also avoids uneven wear of the grinding surface 102.

- As shown in FIG. 14, the grindstone 101 is moved in the extension direction of the center line γ between the first position 301 and the second position 302 across the axis α to perform the correction operation. That is, in this case, at the first and second positions 301 and 302, the center line γ of the grindstone 101 is not located on the radial line of the correction surface 110, but is located on a line parallel to the radial line. In this case, it is not necessarily necessary to continue the motor drive of the correction grindstone 100 without stopping the motor drive and to switch the rotation direction. In addition, when the correction grindstone 100 and the processing grindstone 101 are arranged in the positional relationship of FIG. 14, the processing grindstone 101 may be moved parallel to the center line γ at both the first position 301 and the second position 302. In this case, it is preferable to continue the motor drive of the correction grindstone 100 without stopping it and to switch the rotation direction at the first position 301 and the second position 302. This method also helps to avoid uneven wear of the grinding surface 102.

- As shown in FIG. 15, in the configuration of the second embodiment, the processing grindstone 101 is arranged so that its center line γ is located on a radial line passing through the axis α of a pair of correction grindstones 100. Then, as shown by the solid line and the two-dot chain line, the processing grindstone 101 is moved between the first position 301 and the second position 302, straddling the axis α of both correction grindstones 100. Even in this case, the rotation direction of the correction grindstone 100 is not switched, and it continues to rotate in the Q direction or the R direction. Even with this method, uneven wear of the grinding surface 102 can be avoided.

-As shown in FIG. 16, the grindstone 101 is set at a first position 301 and a second position 302 outside the position between the axes α of the two correction grindstones 100. Then, the grindstone 101 is moved in the diagonal direction in FIG. 16 between the first position 301 and the second position 302 through the gap between the two correction grindstones 100. In this case, at the first and second positions 301 and 302, the center line γ of the grindstone 101 is not positioned on the radial line of the correction surface 110, but is positioned on a line parallel to the radial line. In this case, the motor drive of the correction grindstone 100 is continued without stopping, and it is not necessarily necessary to switch the rotation direction. With this method as well, uneven wear of the grinding surface 102 can be avoided.

- The grinding surface 102 of the grinding wheel 101 after correction is photographed with a camera to obtain an image, which is then compared with a preset reference image to automatically evaluate the condition of the grinding surface 102. Then, when the correction of the grinding surface 102 reaches a predetermined level, the correction is terminated.

- The distance between the two correction grindstones 100 should be wider than the width of the processing grindstone 101. In this case, it is preferable to continue rotating the correction grindstone 100 without stopping the motor drive.

- In the second embodiment, the rotation interlocking configuration using the belt 31 is omitted. In this configuration, if the distance between the outer circumferences of the closest parts of the two correction grindstones 100 is narrower than the width of the processing grindstone 101, even if the processing grindstone 101 is positioned between the correction grindstones 100, it will continue to contact at least one of the correction grindstones 100. Therefore, when the processing grindstone 101 moves from one correction grindstone 100 to the other correction grindstone 100, the processing grindstone 101 of the other correction grindstone 100 starts to rotate in a following manner.

- In the second embodiment, the first position 301 and the second position 302 are located on the axis α of the correction surface 110 of both correction grindstones 100, and are located opposite each other at two locations outside the position between both axes α. In other words, the first position 301 and the second position 302 are located outside the portion between both axes α.

- The grindstone 101 is held in a fixed position without moving it at the first position 301, the second position 302, etc. In this way, uneven wear of the grinding surface 102 can be avoided. However, in this case, it is preferable to use a correction grindstone 100 that is less prone to wear.

In the first and second embodiments, the correcting grindstone 100 is driven by a motor only in the initial stage of the correcting process. However, the correcting grindstone 100 may be driven by a motor from the initial stage of the correcting process to the final stage of the correcting process.
Instead of the correction grindstone 100, a metal disk having a correction surface 110 with knurling or a large number of grooves extending in radial directions may be used as the rotary correction body.

- Use a viscous metal such as stainless steel as the rotation corrector.
(Other technical ideas)
The technical ideas grasped from the first and second embodiments and the modified examples are as follows.

(A) A grinding surface correction system for a processing grindstone having a grinding machine with a processing grindstone and a correction device attached to the grinding machine and having a rotating correction body that corrects the grinding surface of the processing grindstone, the system being provided with a control means for rotating the peripheral speed of the grinding surface of the processing grindstone and the peripheral speed of the correction surface of the rotating correction body in the same direction at the same speed.

(B) A correction device according to the above item (A), in which a pair of rotation correction bodies are provided, and both rotation correction bodies are linked via a ring rope.
(C) The straightening device according to (B), wherein the distance between the rotary straightening bodies is narrower than the width between the two grinding wheels.

11... Grinding machine 100... Grinding wheel for correction 101... Grinding wheel for processing 102... Grinding surface 110... Correction surface α... Axis line β... Axis line γ... Center line Q... Rotation direction R... Rotation direction

Claims (6)

A method for correcting a grinding surface of a grinding wheel, comprising the steps of: using a rotary correction body that is rotated about a first axis and has a correction surface located in a plane perpendicular to the first axis; and contacting a grinding surface provided on an outer peripheral surface of a grinding wheel that rotates about a second axis extending in a direction perpendicular to the first axis with the correction surface to correct the grinding surface, the method comprising the steps of:
When viewed from a direction along the first axis, the grindstone is arranged so that the second axis overlaps with a diameter of the rotation correction body and a center line passing through the center of the grindstone in the width direction overlaps with a chord other than the diameter of the rotation correction body,
The grinding surface is corrected at two different locations on the correction surface, and the relationship between one and the other sides in the width direction of the grinding wheel and the outer and inner sides of the portion of the correction surface against which the grinding surface is contacted is reversed at the two locations . 2. The method for correcting the grinding surface of a grindstone according to claim 1, further comprising the step of switching a rotation direction of said rotation correction body so that the rotation directions of said rotation correction body are opposite to each other at said two locations . A method for correcting the grinding surface of a grinding wheel according to claim 1 or 2, in which the rotating correction body is rotated in a manner following the grinding wheel. A method for correcting a grinding surface of a grinding wheel, comprising the steps of: using a pair of rotary correction bodies which are rotated in the same direction as each other about a first axis which is parallel to each other and each have a correction surface located in a plane perpendicular to the first axis; and contacting a grinding surface provided on an outer peripheral surface of a grinding wheel which rotates about a second axis which extends in a direction perpendicular to the first axis with the correction surface to correct the grinding surface,
When viewed from a direction along the first axis, the second axis is aligned with both diameters of the rotation correction body, and a center line passing through the center of the width direction of the grindstone is aligned with a chord other than the diameter of the rotation correction body.
The grinding surface is corrected by each of the correction surfaces of a pair of rotation correction bodies , and the relationship between one and the other sides in the width direction of the grinding wheel and the outer and inner sides of the correction surfaces of the rotation correction body at the portions where the grinding surfaces are in contact is reversed between the correction surfaces of the pair of rotation correction bodies . 5. The method for modifying the grinding surface of a grindstone according to claim 4, wherein the modification is performed at a position between the first axes. The pair of rotation correction bodies are drivingly connected to each other,
6. The method for correcting the grinding surface of a grindstone according to claim 4, wherein both of said rotary correction bodies are rotated following the rotation of said grindstone.