JP2021074834A - Grinding device - Google Patents

Abstract

To provide a grinding device that can be suppressed from deterioration in processing accuracy due to influence of variation of an outer diameter of an object to be ground during grinding.SOLUTION: A grinding device 1 comprises a grinding wheel head 3 which is mounted with a grindstone 2 and rotates the grindstone 2 and a headstock 4 that rotatably holds a shaft-like object 7 to be ground, which grinds the object 7 to be ground, with the grindstone 2 while relatively moving the grindstone 2 and the object 7 to be ground in an axial direction. The device further comprises a rest device 6 having first and second contact makers 11a and 11b, arranged side by side in the axial direction, which are pressed against the object 7 to be ground so as to suppress deflection of the object 7 to be ground, when grinding the object 7 to be ground with the grindstone 2, and a control device 20 that controls the rest device 6. The control device 20 has a contact maker control part 21 that increases and decreases push-in force of the first and second contact makers 11a and 11b respectively, accompanying relative movements of the grindstone 2 and the object 7 to be ground, while keeping total pressing-in force of the first and second contact makers 11a and 11b constant.SELECTED DRAWING: Figure 1

Description

The present invention relates to a grinding device including a rest device.

A grinding device that has a grindstone base on which a grindstone is attached to rotate the grindstone and a spindle base that rotatably holds a shaft-shaped grinding object, and grinds the grinding object while moving the rotating grindstone in the axial direction. Are known. As such a grinding device, there is known one provided with a rest device that presses a contact against the object to be ground to suppress the deflection of the object to be ground when grinding the object to be ground with a grindstone (for example, a patent). Reference 1).

Japanese Patent No. 2602965

In a conventional grinding device, when the grindstone passes through a position facing the contactor of the rest device, the outer diameter of the object to be ground is changed by grinding, that is, due to the influence of the step between the ground portion and the unground portion. There was a moment when the object to be ground and the contact were not in contact with each other, and when the contact was brought into contact with the object to be ground again, the object to be ground vibrated and the machining accuracy was deteriorated.

Therefore, an object of the present invention is to provide a grinding apparatus capable of suppressing deterioration of machining accuracy due to the influence of a change in the outer diameter of a grinding object during grinding.

The present invention is provided with a grindstone base on which a grindstone is attached to rotate the grindstone, and a spindle base for rotatably holding a shaft-shaped grinding object, for the purpose of solving the above problems. A grinding device that grinds the grinding object with the grindstone while moving the grinding object relative to the axial direction. When the grinding object is arranged side by side in the axial direction and the grinding object is ground with the grindstone, the grinding object is ground. A rest device having first and second contacts that are pressed against the grinding object and suppress the deflection of the grinding object, and a control device that controls the rest device are provided, and the control device is the first. While maintaining the total pushing force of the first and second contacts constant, the pushing force of the first and second contacts is increased or decreased as the grindstone and the object to be ground move relative to each other. Provided is a grinding device having a contactor control unit.

According to the present invention, it is possible to provide a grinding apparatus capable of suppressing deterioration of machining accuracy due to the influence of a change in the outer diameter of a grinding object during grinding.

It is a schematic diagram of the grinding apparatus which concerns on one Embodiment of this invention. It is a schematic block diagram which shows the structural example of the 1st and 2nd rest devices when viewed along the rotation axis direction of the object to be ground. (A) to (d) are diagrams for explaining the operation of the first and second contacts. It is a graph which shows an example of the time change of the pushing force of the 1st and 2nd contactors, and the pushing force of the total pushing force. It is a flow figure which shows an example of the control flow at the time of grinding.

[Embodiment]
Embodiments of the present invention will be described with reference to FIGS. 1 to 5. It should be noted that the embodiments described below are shown as suitable specific examples for carrying out the present invention, and there are some parts that specifically exemplify various technically preferable technical matters. , The technical scope of the present invention is not limited to this specific aspect.

(Overall configuration of grinding equipment)
FIG. 1 is a schematic view of a grinding device according to the present embodiment. As shown in FIG. 1, the grinding device 1 is movable in a direction parallel to the rotation axis of the grindstone 2 (the axial direction of the grinding object 7) and the grindstone base 3 on which the grindstone 2 is attached to rotate the grindstone 2. A table 8 provided, a headstock 4 and a tailstock 5 for rotatably holding a shaft-shaped object 7 to be ground, a rest device 6 for suppressing bending of the object to be ground during grinding, and a rest device 6 20 and a control device 20 for controlling the above.

The grindstone base 3 and the spindle base 4 are placed on the bed 10. In the grinding device 1, the grindstone base 3 is provided so as to be movable in a direction perpendicular to the rotation axis of the grindstone 2 (cutting direction of the grindstone 2). The grindstone base 3 is feed-controlled in the cutting direction of the grindstone 2 via a servomotor 30, an encoder 31, and a ball screw (not shown). The headstock 4 is arranged to face the tailstock 5, and is configured to rotatably support the grinding object 7 by sandwiching the grinding object 7 between the headstock 4 and the tailstock 5. There is.

The rest device 6, the spindle base 4, and the tailstock 5 are placed on the table 8. In the grinding device 1, the grindstone table 3 is moved to bring the grindstone 2 closer to the object to be ground 7, and the rotating grindstone 2 is cut into the object to be ground 7, and the table 8 is moved to move the grindstone 2 and the object to be ground. It is configured to grind the object 7 to be ground by the rotating grindstone 2 while relatively moving the object 7 in the axial direction. The table 8 is fed and controlled in the axial direction of the object 7 to be ground via the servomotor 40, the encoder 41, and the ball screw (not shown). The object to be ground 7 is a long object having a circular cross section perpendicular to the longitudinal direction thereof.

(Rest device 6)
FIG. 2 is a schematic view showing a configuration example of the rest device 6 viewed from the axial direction along the rotation axis of the grinding object 7 together with a part of the grinding object 7 and the grindstone 2. In FIG. 2, the rotation directions of the grindstone 2 and the object to be ground 7 are indicated by arrows. In the following description, "upper" and "lower" shall mean up and down in the vertical direction.

The rest device 6 is for suppressing the bending of the grinding object 7 due to the load of the grindstone 2 when the grinding object 7 is ground by the grindstone 2. The rest device 6 is placed on the table 8 together with the spindle base 4 and the tailstock 5, and is fixed to the table 8 so that the relative position with respect to the grinding object 7 is a constant position. The rest device 6 is provided so as to support the axially central portion of the object 7 to be ground.

In the present embodiment, the rest device 6 comprises a first rest device 6a having a first contact (shoe) 11a and a second rest device 6b having a second contact (shoe) 11b. Have. The first and second contacts 11a and 11b are arranged side by side in the axial direction, and when the grinding object 7 is ground by the grindstone 2, the first and second contacts 11a and 11b are pressed against the grinding object 7 to cause the deflection of the grinding object 7 to be deflected. It plays a suppressive role.

In the present embodiment, the first and second rest devices 6a and 6b are the first rest mechanism portion 61 and the first rest mechanism portion 61 arranged on the side opposite to the grindstone 2 in the axial view of the grinding object 7. It has a second rest mechanism portion 62 arranged below the rest mechanism portion 61, and a support 63 attached to the table 8, respectively. The first and second rest mechanism portions 61 and 62 are supported by the support 63.

The first rest mechanism portion 61 is first via a first case member 611 fixed to the support 63, a first servomotor 612 fixed to the first case member 611, and a coupling 613. The ball screw shaft 614 connected to the output shaft 612a of the servomotor 612, the ball screw nut 615 arranged on the outer periphery of the ball screw shaft 614, and the ball screw nut 614 move forward and backward together with the ball screw shaft 614. It has a working member 616 of No. 1 and a contactor 111 attached to the first working member 616 via a bolt 113. The contactor 111 has a contact surface 111a in contact with the outer peripheral surface of the object 7 to be ground, which is opposite to the grindstone 2 side.

The first servomotor 612 is an actuator that operates the first operating member 616, generates torque by the motor current supplied from the control device 20, and rotationally drives the ball screw shaft 614. The ball screw nut 615 is detented with respect to the first case member 611, and the first operating member 616 is moved linearly along the rotation axis of the ball screw shaft 614 to the first case member 611. Guidance is supported. When the ball screw shaft 614 is rotationally driven in one direction by the first servomotor 612, the first operating member 616 advances toward the grinding object 7, and the contact 111 is axially centered on the grinding object 7. Contact the part. Further, when the ball screw shaft 614 is rotationally driven in the opposite direction, the contact 111 is separated from the object 7 to be ground.

The second rest mechanism portion 62 includes a second case member 621 fixed to the support 63 below the first case member 611, and a second servomotor 622 fixed to the second case member 621. The ball screw shaft 624 connected to the output shaft 622a of the second servomotor 622 via the coupling 623, the ball screw nut 625 arranged on the outer periphery of the ball screw shaft 624, and the rotation of the ball screw shaft 624. A rod 626 that moves forward and backward together with the ball screw nut 625, a second operating member 627 that rotates about a support shaft 631 provided on the support 63 as the rod 626 moves forward and backward, and a second operation. It has a contact 112 attached to the member 627 via a bolt 114. The contactor 112 has a contact surface 112a in contact with the outer peripheral surface at the lower end of the object 7 to be ground.

The second servomotor 622 is an actuator that operates the second operating member 627, generates torque by the motor current supplied from the control device 20, and rotationally drives the ball screw shaft 624. The ball screw nut 625 is prevented from rotating with respect to the second case member 621, and the rod 626 is guided and supported by the second case member 621 so as to be linearly movable along the rotation axis of the ball screw shaft 624. There is. The rod 626 and the second operating member 627 are rotatably connected by a pivot shaft 629. When the ball screw shaft 624 is rotationally driven by the second servomotor 622 in one direction, the rod 626 protrudes from the second case member 621 and the second operating member 627 rotates about the support shaft 631. The contact 112 comes into contact with the axially central portion of the object 7 to be ground. Further, when the ball screw shaft 624 is rotationally driven in the opposite direction, the contact 112 is separated from the object 7 to be ground. The second rest mechanism portion 62 is not essential and can be omitted.

The first and second contacts 11a and 11b (contacts 111 and 112) are made of a superhard material, and for example, diamond compaq, which is a diamond sintered body obtained by sintering fine diamond particles, is used as the first and second contacts. Can be suitably used as a material for the contacts 11a and 11b.

Further, the grinding device 1 includes a pushing force detecting unit 23 for detecting the pushing force of the first and second contacts 11a and 11b (contacts 111 and 112) into the grinding object 7. In the present embodiment, the pushing force detecting unit 23 is configured to detect the current value (that is, power) of the current that drives the servomotors 612 and 622. In the present embodiment, the pushing force detecting unit 23 is mounted on the control device 20, but the present invention is not limited to this, and the pushing force detecting unit 23 may be configured separately from the control device 20. Further, in the present embodiment, the pushing force detecting unit 23 is configured to detect the current value of the servomotors 612 and 622, but the present invention is not limited to this, and for example, the pushing force detecting unit 23 is a strain gauge or a load measuring device. Etc. may be used. When a strain gauge or load measuring device is used, the strain gauge or load measuring device shall be provided between the contact 111 and the first operating member 616, or between the contact 112 and the second operating member 627. Can be done.

(Control device 20)
The control device 20 is realized by appropriately combining arithmetic elements, memories, storage devices, interfaces, software, and the like. The control device 20 includes a contact control unit 21, a storage unit 22, and a pushing force detecting unit 23.

The contact control unit 21 drives the servomotors 612 and 622 to cut the grindstone 2 into the grinding object 7 at a preset position (the second contact 11b cuts the grindstone 2 by the cutting amount). The first and first contacts 11a are located at positions corresponding to the machining diameter of the grinding object 7 obtained later. The first contact 11a is located at the position corresponding to the outer peripheral diameter of the grinding object 7 before cutting the grindstone 2 by the cutting amount. 2 The contacts 11a and 11b (contacts 111 and 112) are moved, respectively, and the objects 7 to be ground are supported by the contacts 11a and 11b. In this state, the grindstone 2 is moved relative to the grinding object 7 in the axial direction, and traverse grinding of the grinding object 7 is performed. Hereinafter, the positions of the contacts 11a and 11b to be moved when the grindstone 2 is cut are referred to as the positions at the start of grinding. The grinding start position is preset and stored in the storage unit 22. The contact control unit 21 controls the positions of the contacts 11a and 11b based on the detection value of the encoder that detects the amount of rotation of the output shafts 612a and 622a of the servomotors 612 and 622.

In the grinding device 1, the grindstone 2 is moved relative to the object 7 to be ground in one direction in the axial direction to perform traverse grinding in the first pass, and then the grindstone 2 is further moved by the same depth of cut as in the first pass. The notch and the grindstone 2 are moved relative to the object 7 to be ground in the other direction in the axial direction to perform traverse grinding in the second pass. Similarly, at both ends of the object to be ground 7, the same amount of depth as the depth of cut in the first pass is given to the grindstone 2, and traverse grinding is repeated to grind the object 7 to be ground. That is, in the grinding device 1, traverse grinding in which the grindstone 2 and the grinding object 7 are relatively moved in the axial direction and the grinding object 7 is ground by the grindstone 2 is repeated a plurality of times while reversing the grinding direction. 7 is configured to grind. During traverse grinding, the contact control unit 21 advances the second contact 11b (or the first contact 11a) by a distance equal to the depth of cut of the grindstone 2, and pushes the contact forces 11a and 11b. Is configured to keep constant.

In the grinding apparatus 1 according to the present embodiment, the contact control unit 21 keeps the total pushing force of the first and second contacts 11a and 11b constant, while the grindstone 2 and the grinding object 7 are relative to each other. It is configured to increase or decrease the pushing force of the first and second contacts 11a and 11b as they move.

More specifically, at the start of traverse grinding, the contact control unit 21 pushes the contact force 11b (or 11a) on the traverse grinding end position side and the contactor 11a (or 11b) on the traverse grinding start position side. The end portion in front of the grinding direction (hereinafter referred to as the grinding front side end portion of the grinding wheel 2) of the grinding portion where the grinding wheel 2 is in contact with the grinding object 7 is the contactor 11a (hereinafter referred to as the grinding front side end portion of the grinding wheel 2) on the traverse grinding start position side. Or, after passing through 11b) and when passing through the contactor 11b (or 11a) on the traverse grinding end position side, the pushing force of the contactor 11b (or 11a) on the traverse grinding end position side is small. As a result, the pushing force of the contactor 11a (or 11b) on the traverse grinding start position side is gradually and greatly controlled.

3 (a) to 3 (d) are diagrams for explaining the operation of the first and second contacts 11a and 11b. First, as shown in FIG. 3A, the contact control unit 21 grinds the first and second contacts 11a and 11b together with the cutting of the grindstone 2 into the object to be ground 7 at the start of traverse grinding. Move (advance) to the starting position. That is, the second contact 11b (or the first contact 11a) is moved to a position corresponding to the machining diameter of the grinding object 7 obtained after cutting the grindstone 2 by the cutting amount, and the cutting amount of the grindstone 2 is cut. The first contactor 11a (or the second contactor 11b) is moved to a position corresponding to the outer peripheral diameter of the object 7 to be ground before being cut. As a result, the pushing force of the contactor (here, the second contactor 11b) on the traverse grinding end position side is larger than the pushing force of the contactor (here, the first contactor 11a) on the traverse grinding start position side. Become. If the pushing force of the contactor (here, the first contactor 11a) on the traverse grinding start position side is large, the grinding object 7 is affected by the change in the outer diameter of the grinding object 7 during traverse grinding (falling into a step). It is desirable that the pushing force of the contactor (here, the first contactor 11a) on the traverse grinding start position side is as small as possible, and the object 7 is touched. It is desirable to make it to the extent that At this point, the object 7 to be ground is supported by the second contactor 11b.

After that, as shown in FIG. 3B, the grindstone 2 is moved in the axial direction to perform traverse grinding. At that time, in the contactor control unit 21, after the end portion of the grindstone 2 on the grinding front side has passed through the contactor (here, the first contactor 11a) on the traverse grinding start position side, and on the traverse grinding end position side. When passing through the contactor (here, the second contactor 11b), the pushing force of the contactor (here, the first contactor 11a) on the traverse grinding start position side is gradually increased, and the traverse grinding is completed. The pushing force of the contactor on the position side (here, the second contactor 11b) gradually decreases as the outer peripheral diameter of the object 7 to be ground decreases. After the front end of the grindstone 2 has passed through the contactor on the traverse grinding end position side (here, the second contactor 11b), the contactor on the traverse grinding end position side (here, the second contactor 11b) ), It is desirable that the pushing force is as small as possible, and it is desirable that the pushing force is in contact with the object 7 to be ground.

That is, when the grinding front end of the grindstone 2 passes through the second contactor 11b, the first contactor 11a is advanced and the grinding object 7 in contact with the second contactor 11b is in contact with the second contactor 11b. The outer peripheral diameter of the object 7 is reduced, and the support of the object 7 to be ground is switched from the second contactor 11b to the first contactor 11a. At this time, as shown in FIG. 4, by keeping the total pushing force of the first and second contacts 11a and 11b constant, it is possible to hold the grinding object 7 with a constant pushing force. Become. The first contactor 11a is moved to a position corresponding to the machining diameter of the grinding object 7 obtained after cutting by the depth of cut of the grindstone 2 in the second pass.

When the grinding of the first pass is completed, as shown in FIG. 3C, the grindstone 2 is cut by the same cutting amount as the cutting amount of the first pass. At this point, the object 7 to be ground is supported by the first contactor 11a on the grinding end position side. After that, the grindstone 2 is moved relative to the object 7 to be ground in the axial direction to perform traverse grinding in the second pass. At this time, when the front end of the grindstone 2 is passing through the first contactor 11a, the second contactor 11b is advanced and the object to be ground is in contact with the first contactor 11a. The outer peripheral diameter of 7 is reduced, and the support of the object 7 to be ground is switched from the first contactor 11a to the second contactor 11b. The same control is repeated after the third pass.

In the present embodiment, at the start of traverse grinding of each pass, the contactor 11a (or 11b) on the traverse grinding start position side is brought into contact with the object 7 to be ground to generate a small pushing force, so that traverse grinding is performed. It is detected that the end portion of the grindstone 2 on the grinding front side has passed through the contactor 11b (or 11a) on the traverse grinding end position side due to a change in the pushing force of the contactor 11a (or 11b) on the start position side. Is possible. That is, in the present embodiment, the contactor control unit 21 grinds the grindstone 2 forward based on the change in the pushing force of the contactor 11a (or 11b) on the traverse grinding start position side detected by the pushing force detecting unit 23. It is configured to detect that the side end portion has passed through the contactor 11b (or 11a) on the traverse grinding end position side. However, the present invention is not limited to this, and a means for detecting the grinding front side end portion of the grindstone 2 (or a means for detecting the position of the table 8 (encoder 41)) is provided, and the grinding front side end portion of the grindstone 2 is at a predetermined position. The contacts 11a and 11b that support the grinding object 7 may be switched at the time when the position (the position where the contactor is positively supported is passed) is reached.

Further, the total value of the pushing force of the first and second contacts 11a and 11b may be preset and stored in the storage unit 22, but the optimum pushing force is the cutting amount of the grindstone 2 and grinding. It depends on the material, outer diameter, etc. of the object 7. Therefore, the total value of the pushing force when the first and second contacts 111 and 112 are moved to the grinding start position at the initial stage of use of the first and second contacts 11a and 11b is used as the target pushing force. It is possible to control the contacts 11a and 11b so that the total value of the pushing forces of the first and second contacts 11a and 11b stored in the storage unit 22 becomes the target pushing force stored in the storage unit 22. desirable. In the present embodiment, the pushing force when the first and second contacts 111 and 112 are moved to the preset grinding start position at the time of the first traverse grinding (during the traverse grinding of the first pass) is applied. In addition to being detected by the pushing force detecting unit 23, the total value of the pushing force, that is, the total value of the initial pushing force is stored in the storage unit 22 as the target pushing force, and the first and second contacts 11a, The contacts 11a and 11b are controlled so that the total value of the pushing force of 11b becomes the target pushing force stored in the storage unit 22.

FIG. 2 shows a case where the first and second rest devices 6a and 6b have a first rest mechanism portion 61 and a second rest mechanism portion 62, respectively, but two first rest mechanisms are shown. A target pushing force (total value of pushing force) is set individually for each of the unit 61 and the two second rest mechanism units 62, and the contacts 11a and 11b are individually controlled. That is, different target pushing forces are set for the two first rest mechanism portions 61 and the two second rest mechanism portions 62, and the total value of the pushing forces of the first and second contacts 11a and 11b. The switching control of the contacts 11a and 11b supporting the grinding object 7 is performed so that is maintained at a constant target pushing force. However, the present invention is not limited to this, and for example, switching control of the contacts 11a and 11b may be performed only on the first rest mechanism portion 61 in which the pushing force is relatively large.

(Control flow)
FIG. 5 is a flow chart showing an example of a control flow during grinding. As shown in FIG. 5, after setting the grinding object 7 on the spindle 4, in step S1, the contact control unit 21 cuts the grindstone 2 and sets the first pass in the storage unit 22. The first and second contacts 11a and 11b are advanced to the grinding start position during traverse grinding (see FIG. 3A). At this time, the pushing force of the contactor 11a (or 11b) on the traverse grinding start position side is made minute, and the grinding object 7 is supported by the contactor 11b (or 11a) on the traverse grinding end position side.

After that, in step S2, the initial pushing force (here, the current value of the servomotors 612 and 622) when the first and second contacts 11a and 11b are advanced to the position at the start of grinding is pushed. Each is detected by the detection unit 23, and the total pushing force is stored in the storage unit 22 as the target pushing force. Then, in step S3, the traverse grinding of the first pass is started while the grindstone 2 is laterally fed.

After that, in step S4, it is determined whether or not the grinding front end portion of the grindstone 2 has passed through the contactor 11b (or 11a) on the traverse grinding end position side. If NO is determined in step S4, step S4 is repeated to continue traverse grinding. If YES is determined in step S4, the contactor 11a (or 11b) on the traverse grinding start position side is advanced and is in contact with the contactor 11b (or 11a) on the traverse grinding end position side in step S5. The outer peripheral diameter of the object to be ground 7 is reduced, and the contacts 11a and 11b supporting the object to be ground 7 are switched (see FIGS. 3 (b) and 3 (d)). At this time, the both contacts 11a and 11b are controlled so that the total value of the pushing forces of the contacts 11a and 11b is constant (the target pushing force stored in the storage unit 22).

After that, in step S6, it is determined whether or not the traverse grinding of this pass is completed. If NO is determined in step S6, step S6 is repeated to continue traverse grinding. If YES is determined in step S6, it is determined in step S7 whether the traverse grinding of the final pass is completed. If NO is determined in step S7, the grindstone 2 is cut by the cutting amount in step S8, the process returns to step S3, and traverse grinding of the final pass is started (see FIG. 3C). If YES is determined in step S7, grinding is terminated.

(Actions and effects of embodiments)
As described above, in the grinding device 1 according to the present embodiment, the rest device 6 has first and second contacts 11a and 11b arranged side by side in the axial direction, and the first and second contacts 11a and 11b are provided. While maintaining the total pushing force of the second contacts 11a and 11b constant, the pushing force of the first and second contacts 11a and 11b is increased as the grindstone 2 and the grinding object 7 move relative to each other. Each is configured to be adjustable.

With this configuration, the contacts 11a and 11b that support the grinding object 7 are switched according to the position of the grinding front side end of the grindstone 2, and the grinding target is ground at the grinding front end where a step is generated. It is possible not to support the object 7, and it is possible to prevent the object 7 to be ground from swinging due to the influence of the step and the machining accuracy from deteriorating.

(Additional note)
Although the present invention has been described above based on the embodiments, these embodiments do not limit the invention according to the claims. It should also be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

In addition, the present invention can be appropriately modified and implemented without departing from the spirit of the present invention. For example, in the above embodiment, the case where the first rest device 6a for driving the first contact 11a and the second rest device 6b for driving the second contact 11b are separately configured will be described. However, the first rest device 6a and the second rest device 6b may be integrally configured.

Further, in the above embodiment, the case where the first contactor 11a and the second contactor 11b have two (two pairs) contacts has been described, but three or more (three pairs or more) contacts. May have. In this case, the contactor that supports the grinding object 7 may be appropriately switched so that the contactor does not support the grindstone 2 at a position where the front end portion of the grindstone 2 passes.

Further, in the above embodiment, the case where the contacts 11a and 11b are driven by the servomotor has been described, but the present invention is not limited to this, and for example, the contacts 11a and 11b may be driven by a hydraulic or pneumatic cylinder. Good. In this case, it is also possible to control the pushing force by the driving pressure of the cylinder.

1 ... Grinding device 2 ... Grinding stone 3 ... Grinding base 4 ... Headstock 5 ... Traction base 6 ... Rest device 6a ... First rest device 6b ... Second rest device 61 ... First rest mechanism 611 ... First Case member 612 ... First servomotor 612a ... Output shaft 613 ... Coupling 614 ... Ball screw shaft 615 ... Ball screw nut 616 ... First operating member 62 ... Second rest mechanism 621 ... Second case member 622 ... Second servomotor 622a ... Output shaft 623 ... Coupling 624 ... Ball screw shaft 625 ... Ball screw nut 626 ... Rod 627 ... Second operating member 629 ... Pivot shaft 63 ... Support 631 ... Support shaft 7 ... Grinding Object 8 ... Table 10 ... Bed 11 ... Contact 11a ... First contact 11b ... Second contact 111, 112 ... Contact 111a, 112a ... Contact surface 20 ... Control device 21 ... Contact control unit 22 ... Storage unit 23 ... Pushing force detection unit

Claims (4)

A grindstone stand to which a grindstone is attached and rotates the grindstone,
Equipped with a spindle that rotatably holds the shaft-shaped grinding object,
A grinding device that grinds the object to be ground by the grindstone while relatively moving the grindstone and the object to be ground in the axial direction.
A rest device that is arranged side by side in the axial direction and has first and second contacts that are pressed against the grinding object and suppress the deflection of the grinding object when the grinding object is ground by the grindstone. ,
A control device for controlling the rest device is provided.
The control device maintains the total pushing force of the first and second contacts at a constant level, and the first and second contacts are moved as the grindstone and the object to be ground move relative to each other. It has a contactor control unit that increases or decreases the pushing force of the wheel.
Grinding device. Traverse grinding, in which the grindstone and the object to be ground are relatively moved in the axial direction and the object to be ground is ground by the grindstone, is repeated a plurality of times while reversing the grinding direction so as to grind the object to be ground. Has been
At the start of grinding the traverse grinding, the contact control unit applies the pushing force of the contacts on the traverse grinding end position side of the first and second contacts to the pushing force of the first and second contacts. After the pushing force of the contactor on the traverse grinding start position side is made larger than the pushing force of the contactor on the side of the traverse grinding start position, and the end portion of the grinding portion in contact with the object to be ground in front of the grinding direction passes through the contactor on the grinding start position side. In addition, as the pushing force of the contactor on the traverse grinding end position side gradually decreases while passing through the contactor on the traverse grinding end position side, the contactor on the traverse grinding start position side is pushed in. Gradually control the force,
The grinding apparatus according to claim 1. A pushing force detecting unit for detecting the pushing force of the first and second contacts into the object to be ground is provided.
The contactor control unit moves forward in the grinding direction of the grinding portion where the grindstone is in contact with the object to be ground, based on the change in the pushing force of the contactor on the traverse grinding start position side detected by the pushing force detecting unit. Detects that the end of the traverse has passed through the contactor on the traverse grinding end position side.
The grinding apparatus according to claim 2. The contact control unit is configured to move the first and second contacts to preset positions when the grindstone is cut into the object to be ground.
The contact control unit detects the pushing force when the first and second contacts are moved to the preset positions during the initial grinding of the contact, and the pushing force detecting unit detects the pushing force. The total value of the pushing force is stored as a target pushing force, and the first and second contacts are controlled so that the total pushing force of the first and second contacts becomes the target pushing force. To do
The grinding apparatus according to claim 3.

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