JP7363393B2 - grinding equipment - Google Patents

Description

The present invention relates to a grinding device equipped with a rest device.

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

Patent No. 2602965

In conventional grinding devices, materials such as cemented carbide, diamond, etc., which have excellent wear resistance, have been used as contacts of rest devices. Therefore, when grinding is performed using the rest device, there is a problem in that sliding marks of the contacts remain on the surface of the object to be ground. In order to prevent contactors from leaving sliding marks, conventional grinding equipment cannot use a rest device in the finishing process of grinding. It is necessary to reduce the depth of cut and spend more time grinding, which may reduce productivity.

In order to solve this problem, by using a relatively soft material for the contactor, that is, a material with low hardness and elastic modulus that is less aggressive to the object to be ground (e.g., fiber material or resin material), the surface of the object to be ground can be improved. It is possible to reduce the amount of sliding marks that are formed on the surface. However, in this case, wear and deformation are likely to occur in the contact, which may cause the position of the tip of the contact to change, causing deflection of the object to be ground, resulting in deterioration of machining accuracy.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a grinding device that can suppress deterioration of processing accuracy even when the contacts of the rest device are worn or deformed.

In order to solve the above-mentioned problems, the present invention provides a grindstone head to which a whetstone is attached and rotates the whetstone, a headstock that rotatably holds a shaft-shaped object to be ground, and an object to be ground by the grindstone. A rest device that presses a contactor against the object to be ground to suppress deflection of the object to be ground when grinding an object, and a control device that controls the rest device, the grindstone and the object to be ground. A grinding device for grinding the object to be ground with the grindstone while relatively moving the grinding wheel in the axial direction, the grinding device comprising: a pushing force detection section for detecting a pushing force of the contactor onto the object to be ground; The control device includes a contact position control section that moves the contact to a preset position when the grindstone cuts into the object to be ground, and a push-in force detected by the push-in force detection section that determines whether the push-in force is a predetermined target push-in. a contactor position correction section that corrects the position of the contactor so that the pushing force is increased when the contactor is moved to the preset position. Provided is a grinding device that detects the pressing force and corrects the position of the contact from the preset position so that the pressing force becomes the target pressing force.

According to the present invention, it is possible to provide a grinding device that can suppress deterioration of processing accuracy even when a contactor of a rest device is worn or deformed.

1 is a schematic diagram of a grinding device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing an example of the configuration of the rest device when viewed along the rotational axis direction of the object to be ground. FIG. 7 is an explanatory diagram illustrating correction of the position of a contact when wear or deformation occurs in the contact. It is a flow diagram which shows an example of the control flow at the time of grinding. (a) to (d) are diagrams illustrating the operation of the grindstone and the rest device during grinding. It is a flow diagram which shows an example of the control flow at the time of grinding. FIG. 2 is a graph diagram showing an example of a change in pushing force of a contact over time during grinding.

[Embodiment]
Embodiments of the present invention will be described with reference to FIGS. 1 to 7. The embodiments described below are shown as preferred specific examples for carrying out the present invention, and some portions specifically illustrate various technical matters that are technically preferable. However, the technical scope of the present invention is not limited to this specific embodiment.

(Overall configuration of grinding device)
FIG. 1 is a schematic diagram of a grinding device according to this embodiment. As shown in FIG. 1, the grinding device 1 includes a grinding wheel 2 attached thereto, a grinding wheel table 3 that rotates the grinding wheel 2, and a grinding device 1 that is movable in a direction parallel to the rotational axis of the grinding wheel 2 (in the axial direction of the object to be ground 7). A table 8 provided, a headstock 4 and a tailstock 5 that rotatably hold a shaft-shaped object to be ground 7, a rest device 6 for suppressing deflection of the object to be ground during grinding, and a rest device 6. A control device 20 that controls the.

The grindstone head 3 and the headstock 4 are placed on a bed 10 that serves as a base. In the grinding device 1, the grindstone head 3 is provided so as to be movable in a direction perpendicular to the rotation axis of the grindstone 2 (in the cutting direction of the grindstone 2). The grindstone head 3 is controlled to be fed in the cutting direction of the grindstone 2 via a servo motor 30 and a ball screw (not shown). The headstock 4 is arranged to face the tailstock 5, and is configured to rotatably support the workpiece 7 by sandwiching the workpiece 7 between the headstock 4 and the tailstock 5. There is.

The rest device 6, the headstock 4, and the tailstock 5 are placed on a table 8. In the grinding device 1, the grinding wheel head 3 is moved to bring the grinding wheel 2 closer to the object to be ground 7, and while the rotating grindstone 2 is cutting into the object to be ground 7, the table 8 is moved to separate the grinding wheel 2 and the object to be ground. The rotating grindstone 2 is configured to grind the object 7 while moving the object 7 relative to the object 7 in the axial direction. The table 8 is controlled to be fed in the axial direction of the object to be ground 7 via a servo motor 40 and a ball screw (not shown). The object to be ground 7 is a long object whose cross section perpendicular to its longitudinal direction is circular.

(Rest device 6)
FIG. 2 is a schematic diagram showing an example of the configuration of the rest device 6 as viewed from the axial direction along the rotational axis of the object to be ground 7 together with the object to be ground 7 and a part of the grindstone 2. As shown in FIG. 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" refer to the upper and lower sides in the vertical direction.

The rest device 6 is for suppressing the bending of the grinding object 7 due to the load of the grinding wheel 2 when the grinding object 7 is ground by the grinding wheel 2, and is used to prevent the grinding object 7 from being bent due to the load of the grinding wheel 2. (shoe) 11. The rest device 6 is placed on the table 8 together with the headstock 4 and the tailstock 5, and is fixed to the table 8 so that the relative position with respect to the object 7 to be ground is constant. The rest device 6 is provided to support the axial center portion of the object 7 to be ground.

In the present embodiment, the rest device 6 includes a first rest mechanism section 61 disposed on the opposite side of the grindstone 2 when viewed in the axial direction of the object to be ground 7, and a first rest mechanism section 61 located below the first rest mechanism section 61. It has a second rest mechanism section 62 and a support body 63 attached to the table 8. The first and second rest mechanisms 61 and 62 are supported by a support 63.

The first rest mechanism section 61 connects a first case member 611 fixed to a support body 63, a first servo motor 612 fixed to the first case member 611, and a first servo motor 612 via a coupling 613. a ball screw shaft 614 connected to an output shaft 612a of a servo motor 612; a ball screw nut 615 disposed on the outer periphery of the ball screw shaft 614; The first operating member 616 has a first contact 111 attached to the first operating member 616 via a bolt 113.

The first servo motor 612 is an actuator that operates the first actuating member 616 , generates torque by motor current supplied from the control device 20 , and rotationally drives the ball screw shaft 614 . The ball screw nut 615 is prevented from rotating with respect to the first case member 611, and the first actuating member 616 is linearly movable on the first case member 611 along the rotation axis of the ball screw shaft 614. Guidance is supported. When the ball screw shaft 614 is rotationally driven in one direction by the first servo motor 612, the first actuating member 616 advances toward the object to be ground 7, and the first contactor 111 moves toward the object to be ground 7. It comes into contact with the central part in the axial direction. Further, when the ball screw shaft 614 is rotationally driven in the opposite direction, the first contactor 111 is separated from the object to be ground 7 .

The second rest mechanism section 62 includes a second case member 621 fixed to the support body 63 below the first case member 611, and a second servo motor 622 fixed to the second case member 621. , a ball screw shaft 624 connected to the output shaft 622a of the second servo motor 622 via a coupling 623, a ball screw nut 625 disposed on the outer periphery of the ball screw shaft 624, and rotation of the ball screw shaft 624. a rod 626 that moves forward and backward together with the ball screw nut 625; a second actuating member 627 that rotates around a support shaft 631 provided on the support body 63 as the rod 626 moves forward and backward; A second contact 112 is attached to the member 627 via a bolt 114.

The second servo motor 622 is an actuator that operates the second actuating member 627, generates torque by 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 actuating member 627 are rotatably connected by a pivot shaft 629. When the ball screw shaft 624 is rotationally driven in one direction by the second servo motor 622, the rod 626 protrudes from the second case member 621 and the second operating member 627 rotates about the support shaft 631. The second contactor 112 comes into contact with the axial center of the object 7 to be ground. Further, when the ball screw shaft 624 is rotationally driven in the opposite direction, the second contactor 112 is separated from the object to be ground 7 . Note that the second rest mechanism section 62 is not essential and can be omitted.

In this embodiment, the contacts 11 (first and second contacts 111, 112) are made of a material softer than the object to be ground 7. As the contactor 11, it is desirable to use a material having low hardness and elastic modulus and low aggressiveness against the object to be ground 7, and for example, a material made of a fiber material or a resin material can be used. Thereby, it is possible to prevent sliding marks of the contactor 11 from remaining on the surface of the object to be ground 7 during grinding. The first contactor 111 has a contact surface 111a that contacts the outer peripheral surface of the object 7 to be ground on the side opposite to the grindstone 2 side. The second contactor 112 has a contact surface 112a that contacts the outer peripheral surface of the lower end of the object 7 to be ground.

The grinding device 1 also includes a pushing force detection section 24 for detecting the pushing force of the contact 11 onto the object 7 to be ground. In this embodiment, the pushing force detection section 24 is configured to detect the current value (ie, power) of the current that drives the servo motors 612 and 622. In the present embodiment, the push-in force detection section 24 is installed in the control device 20, but the present invention is not limited to this, and the push-in force detection section 24 may be configured separately from the control device 20. Further, in this embodiment, the pushing force detecting section 24 is configured to detect the current values of the servo motors 612 and 622, but the pushing force detecting section 24 is not limited to this, and for example, a strain gauge or a load measuring device can be used as the pushing force detecting section 24. etc. may also be used. When using a strain gauge, load measuring device, etc., place the strain gauge or load measuring device between the first contact 111 and the first actuating member 616, or between the second contact 112 and the second actuating member 627. It can be provided between

(Control device 20)
The control device 20 is realized by appropriately combining arithmetic elements, memories, interfaces, software, and the like. The control device 20 includes a contact position control section 21 , a contact position correction section 22 , a storage section 23 , and a pushing force detection section 24 .

The contact position control unit 21 drives the servo motors 612 and 622 when the grinding wheel 2 cuts into the object 7 to be ground to a preset position (obtained after cutting the grinding wheel 2 by the initial cutting amount). The contact 11 (first and second contacts 111, 112) is moved to a position corresponding to the machining diameter of the object 7 to be ground), and the object 7 to be ground is supported by the contact 11. In this state, the grindstone 2 is moved in the axial direction, and traverse grinding of the object 7 to be ground is performed. Hereinafter, the position of the contactor 11 that is moved when the grindstone 2 makes a cut will be referred to as the grinding start position. In this embodiment, during this traverse grinding, the contact 11 is not moved from the position at the start of grinding, but is held at a constant position. The contact position control unit 21 controls the position of the contact 11 based on the detected value of an encoder that detects the amount of rotation of the output shafts 612a, 622a of the servo motors 612, 622.

In the grinding device 1, after performing the first pass of traverse grinding by moving the grinding wheel 2 relative to the object to be ground 7 in one direction in the axial direction, the grinding wheel 2 is further moved by the same depth of cut as the first pass. A second pass of traverse grinding is performed by moving the grinding wheel 2 relative to the object 7 in the other direction in the axial direction. Similarly, the grindstone 2 is given the same depth of cut as the first pass at both ends of the object 7 to be ground, and traverse grinding is repeated to grind the object 7 to be ground. The contact position control unit 21 is configured to advance the contact 11 by a distance equal to the cutting depth of the grindstone 2 at the start of grinding after the second pass, and to keep the pushing force by the contact 11 constant. .

Here, in this embodiment, since the contact 11 is made of a material softer than the object to be ground 7, the contact 11 is easily subject to wear and deformation. Therefore, it is required to maintain the pushing force of the contact 11 constant regardless of wear or deformation of the contact 11.

Therefore, in the present embodiment, the contact position correction unit 22 is configured to correct the position of the contact 11 so that the pushing force detected by the pushing force detection unit 24 becomes a predetermined target pushing force. ing. More specifically, in this embodiment, the contact position correction unit 22 calculates the pushing force (here, the current value of the servo motor) when the contact 11 is moved to a preset grinding start position. The position of the contact 11 is corrected from a preset position so that the pushing force is detected by the pushing force detection unit 24 and the pushing force (current value of the servo motors 612, 622) becomes the target pushing force (target current value). . For example, the contact position correction unit 22 adjusts the push-in force of the contact 11 based on the push-in force (current value of the servo motors 612, 622) detected by the push-in force detection unit 24 and the target push-in force (target current value). The position of the contact 11 where the force becomes the target pushing force (the amount of rotation of the output shafts 612a, 622a of the servo motors 612, 622) is determined, and the contact 11 is moved to the determined position.

When the contactor position correction unit 22 moves the contactor 11 to a predetermined grinding start position, if the pushing force (current value of the servo motors 612, 622) is smaller than the target pushing force (target current value), The contactor 11 is advanced until the pushing force (current value of the servo motors 612, 622) becomes equal to the target pushing force (target current value). Further, the contact position correction unit 22 determines that when the contact 11 is moved to a predetermined grinding start position, the pushing force (current value of the servo motors 612, 622) is larger than the target pushing force (target current value). In this case, the contactor 11 is moved backward until the pushing force (current value of the servo motors 612, 622) becomes equal to the target pushing force (target current value).

As a result, as shown in FIG. 3, the contact 11 is pushed into the grinding object 7 more when the contact 11 is worn or deformed than when the contact 11 is not worn or deformed. Therefore, the pushing force of the contactor 11 is maintained constant regardless of wear or deformation of the contactor 11.

The target pushing force may be set in advance and stored in the storage unit 23, but the optimum pushing force varies depending on the material, outer diameter, etc. of the object 7 to be ground. Therefore, the pushing force when the contact 11 is moved to the grinding start position during the initial grinding of the contact 11 is stored in the storage unit 23 as the target pushing force, and the push-in force of the contact 11 is stored in the storage unit 23 during subsequent grinding. It is desirable to correct the position of the contactor 11 so that the force becomes the target pushing force stored in the storage unit 23. In this embodiment, the pushing force when the contactor 11 is moved to the preset grinding start position during the first grinding (first pass grinding), that is, the initial pushing force, is used as the target pushing force. During the second and subsequent grinding (second and subsequent passes), the cutting depth of the grinding wheel 2 in the second and subsequent passes is the same as the cutting depth of the grinding wheel 2 in the first pass. In this case, the position of the contact 11 is corrected so that the pushing force of the contact 11 becomes the target pushing force stored in the storage unit 23.

FIG. 2 shows a case where the rest device 6 has a first rest mechanism section 61 and a second rest mechanism section 62; in this case, the first rest mechanism section 61 and the second rest mechanism section 62, target pushing forces are individually set, and position correction control of the contacts 11 (first and second contacts 111, 112) is performed individually. However, the present invention is not limited to this, and the position correction control of the contactor 11 may be performed on at least one of the first rest mechanism section 61 and the second rest mechanism section 62, for example, only on the first rest mechanism section 61. The position correction control of the contactor 11 is performed, and the position correction control of the second rest mechanism section 62 does not need to be performed.

(control flow)
FIG. 4 is a flow diagram showing an example of a control flow during grinding. FIGS. 5(a) to 5(d) are diagrams illustrating the operation of the grindstone and rest device during grinding. As shown in FIG. 2, after the object 7 to be ground is set on the headstock 4, in step S1, the contact position control unit 21 controls the cutting of the grinding wheel 2 and the first pass set in the storage unit 23. The contactor 11 is advanced to the grinding start position during grinding (see FIG. 5(a)).

After that, in step S2, the initial pushing force (here, the current value of the servo motors 612, 622) when the contactor 11 is advanced to the position at the start of grinding is detected by the pushing force detection unit 24, and the This is stored in the storage unit 23 as a pushing force (target current value). Thereafter, in step S3, the first pass of traverse grinding is performed while the grinding wheel 2 is fed laterally (see FIG. 5(b)).

Thereafter, in step S4, the contactor position control unit 21 advances the contactor 11 by a distance equal to the cutting amount of the grindstone 2 while further cutting the grindstone 2 (see FIG. 5(c)). That is, the contactor 11 is moved to the grinding start position during the second pass of grinding. Thereafter, in step S5, the contactor position correction section 22 detects the pushing force of the contactor 11 (here, the current value of the servo motors 612 and 622) using the pushing force detection section 24. Thereafter, in step S6, the contactor position correction unit 22 adjusts the position at the start of grinding so that the pushing force (current value of the servo motors 612, 622) detected in step S5 becomes the target pushing force (target current value). The position of the contactor 11 is corrected from.

Thereafter, in step S7, the second pass of traverse grinding is performed while the grindstone 2 is being fed laterally (see FIG. 3(d)). Thereafter, in step S8, it is determined whether the final pass of grinding has been completed, and if the determination is NO, the process returns to step S4 and the next pass of grinding is performed. If the determination in step S8 is YES, the grinding is finished.

(Actions and effects of embodiments)
As explained above, in the grinding device 1 according to the present embodiment, the position of the contact 11 is corrected so that the pushing force of the contact 11 detected by the pushing force detection unit 24 becomes a predetermined target pushing force. are doing. Thereby, even if wear or deformation occurs in the contactor 11, it is possible to suppress unintended fluctuations in the pushing force of the contactor 11 and to suppress deterioration of processing accuracy. Further, according to the present embodiment, it is possible to compensate for errors caused not only by wear and deformation of the contactor 11 but also by aging deterioration of the rest device 6, thereby improving maintainability and setup efficiency.

(Other embodiments)
In the embodiment described above, only the position of the contact 11 at the start of grinding when the grinding wheel 2 enters the cut is corrected, and the position of the contact 11 is maintained at a constant position during traverse grinding, but the present invention is not limited to this. During grinding, the position of the contact 11 may be corrected so that the pushing force of the contact 11 is constant. Since the grinding resistance by the grindstone 2 is proportional to the force applied to the contact 11, that is, the pushing force of the contact 11, by keeping the pushing force of the contact 11 constant, the grinding resistance can be kept constant. It becomes possible to further improve processing accuracy.

However, in this case, if the position of the contact 11 is finely corrected, there is a risk that uneven grinding may occur. Therefore, in the present embodiment, when the object 7 to be ground is traverse-ground while moving the grinding wheel 2 in the axial direction, when the pushing force of the contact 11 is outside a predetermined threshold range, the pushing force of the contact 11 is The contact position correction unit 22 was configured to correct the position of the contact 11 so that the force was within the threshold range. More specifically, when the pushing force of the contactor 11 becomes larger than a preset upper limit threshold, the contactor position correction unit 22 moves the contactor 11 backward, so that the pushing force of the contactor 11 is adjusted to The contactor 11 is moved forward when the value is greater than the set lower limit threshold. The upper limit threshold and the lower limit threshold may be set appropriately so as to prevent uneven grinding.

Note that during rough machining to remove black scale on the object to be ground 7, fluctuations in grinding resistance increase, so the black scale is removed during rough machining, and the runout of the target object 7 to be ground is suppressed to some extent. In this case, it is desirable to perform position correction control of the contactor 11. Further, since the grinding resistance is not easily reflected in the second rest mechanism part 62, the second rest mechanism part 62 is used to move the contact 11 to the position at the start of grinding during traverse grinding, as in the above embodiment. It is desirable to keep it as it is. That is, the position correction of the contactor 11 during traverse grinding is preferably applied to the first rest mechanism section 61.

FIG. 6 shows an example of a control flow during grinding in this embodiment. In this embodiment, after the object 7 to be ground is set on the headstock 4 and rough machining is performed, the control flow shown in FIG. 6 is executed. As shown in FIG. 6, first, in step S11, the contact position control unit 21 brings the grinding wheel 2 into contact with the grinding start position set in the storage unit 23 during the first pass of grinding. Child 11 is moved forward. Thereafter, in step S12, the first pass of traverse grinding is started while the grindstone 2 is being fed laterally. Thereafter, in step S13, the contact position correction unit 22 determines whether the pushing force of the contact 11 detected by the pushing force detection unit 24 is within a preset threshold range (greater than or equal to the lower limit threshold and less than or equal to the upper threshold). (Limited to traverse grinding before the outer periphery of the object 7 to be ground where the contact 11 is in contact is ground.) (No judgment is made during traverse grinding after the outer periphery has been ground.) If the determination in step S13 is YES, the process advances to step S15. If NO is determined in step S13, the position of the contact 11 is corrected in step S14 so that the pushing force of the contact 11 falls within the threshold range, and then the process proceeds to step S15.

In step S15, it is determined whether the traverse grinding of the current pass has been completed. If the determination in step S15 is NO, the process returns to step S12 and traverse grinding is continued. If the determination in step S15 is YES, it is determined in step S16 whether the final pass of grinding has been completed. If NO is determined in step S16, in step S17, the contactor position control unit 21 advances the contactor 11 by a distance equal to the cutting amount of the grindstone 2 while making further cuts with the grindstone 2, and moves the contactor 11 forward by a distance equal to the cutting amount of the grindstone 2. After moving to the grinding start position during the second pass of grinding, the process returns to step S12 and the second pass of traverse grinding is started. If the determination in step S16 is YES, the grinding is finished.

FIG. 7 is a graph diagram showing an example of a temporal change in the pushing force of the contactor 11 during grinding. FIG. 7 shows temporal changes in the amount of indentation during one traverse grinding. As shown in FIG. 7, according to the present embodiment, the position of the contact 11 is such that when the pushing force of the contact 11 is outside the threshold range, the pushing force of the contact 11 is within the threshold range. is corrected, the pushing force of the contactor 11 can be maintained approximately within the threshold value range, and processing accuracy can be improved. Note that although we did not mention here the position correction of the contactor 11 at the start of traverse grinding (see FIG. 4), the position correction of the contactor 11 at the start of traverse grinding and the position correction of the contactor during traverse grinding. It is naturally possible to do both.

Furthermore, since the grinding resistance differs depending on the material of the object 7 to be ground, etc., during the first pass of traverse grinding, the maximum pushing force (maximum grinding resistance, here the maximum value of the current of the servo motor 612) is detected, Even if the upper and lower thresholds are set based on the detected values, and the position of the contactor 11 is corrected so that the pushing force of the contactor 11 is within the threshold range during traverse grinding from the second pass onwards. good.

In addition, if the error in the relationship between the grinding resistance and the pushing force of the contact 11 becomes large due to the influence of the deviation between the processing position by the grinding wheel 2 and the position of the contact 11, the position of the grinding wheel 2 and the contact 11 The pushing force (grinding resistance) of the contactor 11 may be corrected based on the relationship. Furthermore, although the pushing force of the contactor 11 (current value of the servo motor 612) is used here as an index of grinding resistance, the present invention is not limited to this. For example, when the grinding wheel head 3 is driven by a linear motor, the current of the linear motor It is also possible to detect the grinding resistance based on the value or the like. For example, the position of the contact 11 at the start of traverse grinding is corrected based on the pushing force of the contact 11 (current value of the servo motor), and the position of the contact 11 is corrected during traverse grinding based on the current value of the linear motor that drives the grindstone 3. It is also possible to correct the position of the contactor 11. Further, the grinding resistance detected by the load (amount of current) of the motor that rotates the grindstone 2 may be controlled to be between the upper limit value and the lower limit value.

Note that, according to the present embodiment, by appropriately controlling the threshold value range and controlling the position of the contactor 11, it is also possible to control the grinding resistance by the grindstone 2 and control the actual depth of cut. Therefore, by appropriately controlling the position of the contactor 11, for example by setting the threshold range to gradually change as the grindstone 2 moves, shapes such as a convex center or a concave center can be easily formed. It is also possible to do so.

(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. Furthermore, it should be noted that not all combinations of features described in the embodiments are essential for solving the problems of the invention.

Moreover, the present invention can be implemented with appropriate modifications within a range that does not depart from the spirit thereof. For example, in the above embodiment, a case has been described in which the contact 11 is driven by the servo motors 612 and 622, but the contact 11 is not limited to this, and for example, the contact 11 may be driven by a hydraulic or pneumatic cylinder. . In this case, it is also possible to control the pushing force by the driving pressure of the cylinder.

1... Grinding device 2... Grinding wheel 3... Grinding wheel head 4... Headstock 5... Tailstock 6... Rest device 61... First rest mechanism section 611... First case member 612... First servo motor 612a... Output shaft 613... Coupling 614... Ball screw shaft 615... Ball screw nut 616... First operating member 62... Second rest mechanism section 621... Second case member 622... Second servo motor 622a... Output shaft 623... Cup Ring 624...Ball screw shaft 625...Ball screw nut 626...Rod 627...Second operating member 629...Pivot shaft 63...Support body 631...Support shaft 7...Object to be ground 8...Table 10...Bed 11...Contactor 111... First contact 111a...Contact surface 112...Second contact 112a...Contact surface 20...Control device 21...Contact position control section 22...Contact position correction section 23...Storage section 24...Pushing force detection section

Claims (4)

a whetstone stand to which a whetstone is attached and rotates the whetstone;
a headstock that rotatably holds a shaft-shaped object to be ground;
a rest device that suppresses deflection of the grinding object by pressing a contact against the grinding object when grinding the grinding object with the grindstone;
A control device that controls the rest device,
A grinding device that grinds the object to be ground with the grindstone while relatively moving the grindstone and the object to be ground in the axial direction,
comprising a push-in force detection unit for detecting a push-in force of the contactor to the object to be ground;
The control device includes a contact position control unit that moves the contact to a preset position when the grindstone cuts into the object to be ground, and a push-in force detected by the push-in force detection unit that is set to a predetermined target. a contact position correction unit that corrects the position of the contact so as to provide a pushing force ;
The contact position correction unit detects a pushing force when the contact is moved to the preset position, and adjusts the pushing force from the preset position so that the pushing force becomes the target pushing force. correcting the position of the contact;
Grinding equipment. a storage unit that stores, as the target pushing force, a pushing force when the contact is moved to the preset position during grinding at the initial stage of use of the contact;
The contact position correction unit corrects the position of the contact so that the pushing force of the contact becomes the target pushing force stored in the storage unit during subsequent grinding.
The grinding device according to claim 1 . The contact position correction unit adjusts the push force of the contact when the push force of the contact falls outside a predetermined threshold range when grinding the object to be ground while moving the grindstone in the axial direction. correcting the position of the contact so that it is within the threshold range;
The grinding device according to claim 1 or 2 . The contact is made of a material softer than the object to be ground.
A grinding device according to any one of claims 1 to 3 .

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