JP2017064841A - Grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grinding device capable of suppressing a positional shift of a suction surface of a chuck without reassembling shoes, to thereby enhance processing accuracy.SOLUTION: A grinding device comprises: a front shoe 7 supporting an outer peripheral surface of a workpiece W at the front side; a first rear shoe 8 securing a distance from the outer peripheral surface of the workpiece W, for processing using an inner peripheral surface grinding wheel 12, and supporting the outer peripheral surface of the workpiece W at the opposite side to an outer peripheral surface grinding wheel 11, for processing using the outer peripheral surface grinding wheel 11; and a second rear shoe 9 securing a distance from the outer peripheral surface of the workpiece W, for processing using the outer peripheral surface grinding wheel 11, and supporting the outer peripheral surface of the workpiece W at the opposite side to the inner peripheral surface grinding wheel 12 after moving relatively to the first rear shoe 8, for processing using the inner peripheral surface grinding wheel 12.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a grinding apparatus for grinding an outer peripheral surface and an inner peripheral surface of an annular workpiece.

  Conventionally, as this kind of grinding apparatus, a main shaft extending substantially horizontally, a main shaft driving unit that drives the main shaft to switch between the normal rotation direction and the reverse rotation direction, and a main shaft are attached to adsorb one end surface in the center line direction of the workpiece. A chuck having a suction surface, a first shoe (rear shoe) that supports the outer peripheral surface of the workpiece from the side, a second shoe (front shoe) that supports the outer peripheral surface of the workpiece from below, and an outer peripheral surface of the workpiece The outer peripheral surface grinding wheel for grinding the outer peripheral surface, the inner peripheral surface grinding wheel for contacting the inner peripheral surface of the workpiece and grinding the inner peripheral surface, and the first and second shoes are attached. A device including a shoe movable mechanism that displaces the first and second shoes in the radial direction of the main shaft is known (see, for example, Patent Document 1).

  In this grinding apparatus, the shoe moving mechanism is arranged so that the positions of the first and second shoes are applied to the center of the workpiece so as to apply a pressing force to the first and second shoes on the workpiece when the outer peripheral surface of the workpiece is ground. A first position for decentering the line with respect to the rotation center line of the main shaft, and a center line of the workpiece so that a pressing force against the first and second shoes is applied to the workpiece when grinding the inner peripheral surface of the workpiece. It is configured to switch to a second position that is eccentric with respect to the rotation center line of the main shaft.

Japanese Patent No. 5064122

  However, in the grinding device disclosed in Patent Document 1, the first shoe (rear shoe) is provided at a position that is appropriate when grinding the outer peripheral surface of the workpiece. One shoe (rear shoe) was not placed directly behind the inner peripheral grinding wheel, and grinding could not be performed properly.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a grinding apparatus for grinding an outer peripheral surface and an inner peripheral surface of an annular workpiece, without any change of shoes. However, it is to perform grinding appropriately so that the processing accuracy can be improved.

  In order to achieve the above object, in the present invention, when the eccentric direction of the center line of the workpiece with respect to the rotation center line of the main shaft is changed, the workpiece is supported by the shoe at the optimum position.

  Specifically, the first invention presupposes a grinding apparatus for grinding the outer peripheral surface and the inner peripheral surface of an annular workpiece.

And this grinding device
The spindle,
A spindle drive unit that switches the spindle to forward and reverse rotation, and
A chuck that is attached to the main shaft and has a suction surface that sucks one end surface in the center line direction so that the center line of the workpiece is parallel to the main shaft;
An outer peripheral grinding wheel that contacts the outer peripheral surface of the workpiece on the front side and grinds the outer peripheral surface;
An inner peripheral grinding wheel that contacts the inner peripheral surface of the workpiece and grinds the inner peripheral surface;
A front shoe for supporting the outer peripheral surface of the workpiece on the front side;
A first rear shoe that is spaced from the outer peripheral surface of the workpiece during machining by the inner peripheral grinding wheel and that supports the outer peripheral surface of the workpiece from the opposite side of the outer peripheral grinding wheel during processing by the outer peripheral grinding wheel; ,
When machining with the outer peripheral grinding wheel, the distance from the outer peripheral surface of the workpiece is increased, and when machining with the inner peripheral grinding wheel, the outer peripheral surface of the workpiece is moved toward the inner surface by moving relative to the first rear shoe. A second rear shoe supported from the opposite side of the circumferential grinding wheel.

  According to the above configuration, when machining with the outer peripheral grinding wheel, the outer peripheral surface of the workpiece is supported on the front side by the front shoe, and the outer peripheral surface of the workpiece is supported by the first rear shoe from the opposite side of the outer peripheral grinding wheel. To do. The second rear shoe does not contact the outer peripheral surface of the workpiece. At this time, by supporting the workpiece with the first rear shoe at a position slightly shifted rather than just behind the outer circumferential grinding wheel, it is possible to prevent an increase in the number of projections when there is a projection on the outer circumferential surface of the workpiece. Further, when machining with the inner peripheral surface grinding wheel, the outer peripheral surface of the workpiece is supported on the front side by the front shoe, and the second rear shoe moves relative to the first rear shoe so that the outer peripheral surface of the workpiece is inner peripheral. Support from the opposite side of the surface grinding wheel. For this reason, the inner peripheral surface of the workpiece can be processed with high accuracy. In this way, the work piece can be supported at the optimum position by using the first rear shoe and the second rear shoe separately when grinding the outer peripheral surface of the work piece and when grinding the inner peripheral surface. Here, “front side” means a side on which the outer peripheral grinding wheel is disposed, and the front shoe may be at least in front of the first rear shoe and the second rear shoe. Here, “moves relative to the first rear shoe” means that at least one of the first rear shoe and the second rear shoe moves relative to the other, thereby changing the positional relationship with each other. To do.

In the second invention, in the first invention,
The front shoe and the first rear shoe are attached, and a shoe movable mechanism for displacing the front shoe and the first rear shoe with respect to the main shaft,
The shoe moving mechanism is
The position of the front shoe and the first rear shoe is set so that the center line of the workpiece is applied so that a pressing force against the front shoe and the first rear shoe is applied to the workpiece when the outer peripheral surface of the workpiece is ground. A first position that is eccentric with respect to the rotation center line of the spindle;
Secondly, the center line of the workpiece is decentered with respect to the rotation center line of the main shaft so that a pressing force against the front shoe and the second rear shoe is applied to the workpiece during grinding of the inner peripheral surface of the workpiece. It is configured to switch to the position.

  According to the above configuration, when the workpiece is supported on the front shoe and the first rear shoe which are set to the first position by the shoe moving mechanism, the center line of the workpiece is decentered from the rotation center line of the main shaft. The eccentric direction at this time is a direction in which a pressing force against the front shoe and the rear shoe is applied to the workpiece during grinding of the outer peripheral surface of the workpiece. For this reason, when the main shaft is rotated and the outer peripheral surface of the workpiece is ground by the outer peripheral grinding wheel, the workpiece can be stably supported at a position that is not directly behind the outer peripheral grinding wheel.

  Further, when grinding the inner peripheral surface, the rotation direction of the main shaft is switched to a direction opposite to that during grinding of the outer peripheral surface by the main shaft driving unit. In this case, the position of the shoe is switched from the first position to the second position by the shoe moving mechanism. Then, the eccentric direction of the center line of the workpiece with respect to the rotation center line of the main shaft is a direction in which a pressing force against the front shoe and the second rear shoe is applied to the workpiece when the inner peripheral surface of the workpiece is ground. Thereby, when grinding the internal peripheral surface of a workpiece with an internal peripheral surface grinding wheel, the workpiece is stably supported by the shoe.

  Thus, by providing the shoe moving mechanism, the eccentric direction of the center line of the workpiece with respect to the rotation center line of the spindle is ground and the outer peripheral surface of the workpiece is ground without swinging the headstock as in the conventional structure. It becomes possible to change so as to correspond to the case where the inner peripheral surface is ground and the case where the inner peripheral surface is ground, and the outer peripheral surface and the inner peripheral surface can be ground continuously.

In the third invention, in the second invention,
The shoe moving mechanism is
A base member fixed to a headstock for supporting the main shaft and provided with the second rear shoe;
A shoe holding member provided with the front shoe and the first rear shoe, and supported rotatably about a rotation shaft provided on the base member;
A rotation actuator provided on the base member and configured to press and rotate the shoe holding member;
A rotation position setting section that is provided on the base member and regulates a rotation range of the shoe holding member pressed by the rotation actuator.

  According to the above configuration, by driving the rotation actuator, the shoe holding member can be easily and reliably switched to the first position or the second position, and the outer peripheral surface is ground and the inner circumference is optimally held. Surface grinding can be performed.

In the fourth invention, in the third invention,
The rotation actuator and the rotation position setting unit are provided at positions adjacent to the rotation axis.

  According to the above configuration, by providing the rotation actuator and the rotation position setting unit at adjacent positions, the bending moment that can be generated in the shoe holding member when separated is made as small as possible. Grinding can be performed with high accuracy while preventing deformation.

  According to the present invention, the second rear shoe is moved relative to the first rear shoe at the time of processing by the inner peripheral surface grinding wheel, so that the processing by the outer peripheral surface grinding wheel, the processing by the inner peripheral surface grinding wheel, and the first By properly using the first rear shoe and the second rear shoe, it is possible to improve the processing accuracy by performing appropriate grinding at any grinding position without changing the shoe.

It is a side view showing an outline of a grinding device concerning an embodiment of the present invention. It is the figure which looked at the grinding apparatus which concerns on embodiment along the centerline from the workpiece side, (a) shows the state in which a shoe exists in the position for outer peripheral surface grinding, (b) The state in the position for surface grinding is shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a grinding apparatus 1 according to an embodiment of the present invention. The grinding device 1 is a shoe type centerless grinding device, and is configured to continuously grind the outer peripheral surface and the inner peripheral surface of the annular workpiece W.

  The grinding apparatus 1 includes a main shaft 2, a main shaft base 3 that supports the main shaft 2, and a drive device 4 that rotationally drives the main shaft 2.

  The spindle 2 is supported by a spindle head 3 via a bearing (not shown) in a state where the rotation center line X is disposed horizontally. The drive device 4 includes a motor and a speed reducer (both not shown), and the main shaft 2 is rotated in the counterclockwise direction in FIG. 2 (the direction indicated by the arrow A in FIG. 2A). It is configured to be switched and driven in the clockwise reverse direction (the direction indicated by the arrow B in FIG. 2B).

  As shown in FIG. 1, an electromagnetic chuck 5 is attached to the tip of the main shaft 2. The electromagnetic chuck 5 is configured to adsorb and support one end surface in the center line direction of the workpiece W, and includes an electromagnetic coil (not shown), a tubular main body portion 5a that accommodates the electromagnetic coil, and a main body portion. And a backing plate 5b disposed on the end face of 5a. Although not shown, the electromagnetic coil is connected to a power supply device via wiring, and current is supplied from the power supply device to the electromagnetic coil.

  The backing plate 5b is formed by forming a magnetic metal material in an annular shape, and is fixed to the main body 5a. The front end surface of the backing plate 5b is a suction surface 5c that sucks the workpiece W. The suction surface 5 c is configured by a surface extending perpendicular to the rotation center line X of the main shaft 2. When a current is supplied to the electromagnetic coil, the backing plate 5b is magnetized, and one end surface of the workpiece W is attracted to the attracting surface 5c. The magnitude of the magnetic force of the electromagnetic coil is such that the workpiece W adsorbed on the adsorption surface 5c of the backing plate 5b can slide in the radial direction of the backing plate 5b, and the rotational force of the spindle 2 is the workpiece W It is set to be transmitted to.

  As shown in FIG. 2, the grinding device 1 is in contact with the outer peripheral surface of the workpiece W, and is in contact with the outer peripheral surface grinding wheel 11 for grinding the outer peripheral surface, and the inner peripheral surface of the workpiece W. And an inner peripheral surface grinding wheel 12 for grinding.

  The grinding apparatus 1 also supports a front shoe 7 that supports the outer peripheral surface of the workpiece W from below the front side in FIG. 1 (hereinafter, the front side in FIG. 1 is the front side and the back side is the rear side for explanation). It has. Further, as shown in FIG. 2A, the grinding device 1 includes a first rear shoe 8 that supports the outer peripheral surface of the workpiece W from the opposite side of the outer peripheral surface grinding wheel 11 during processing by the outer peripheral surface grinding wheel 11, and the outer periphery. When machining with the surface grinding wheel 11, the distance from the outer peripheral surface of the workpiece W is increased, and when machining with the inner circumferential surface grinding wheel 12, it moves relative to the first rear shoe 8 as shown in FIG. And a second rear shoe 9 that supports the outer peripheral surface of the workpiece W from the side opposite to the inner peripheral surface grinding wheel 12 (that is, the back side). The sliding surfaces 7a, 8a, 9a of the front shoe 7, the first rear shoe 8, and the second rear shoe 9 are formed along the outer peripheral surface of the workpiece W.

  The front shoe 7, the first rear shoe 8 and the second rear shoe 9 are provided in the shoe movable mechanism 10. The shoe movable mechanism 10 includes a shoe holding member 15 and a base member 16. The base member 16 is fixed with respect to the head stock 3. The shoe holding member 15 is supported so as to be rotatable about a rotation shaft 17 provided on the rear side and the lower side of the base member 16 and is clamped to the base member 16 by a plurality of clamping mechanisms 18. It has become.

  A base end portion of the front shoe 7 is attached to the front side of the shoe holding member 15 by a pin 19 extending in the direction of the rotation center line X of the main shaft 2, and the shoe shoe holding member 15 extends along the outer peripheral surface of the workpiece W. It can be rotated to such an extent that it can be aligned.

  On the other hand, the base end portion of the first rear shoe 8 is attached to the upper and lower intermediate portions on the rear side of the shoe holding member 15 by pins 20 extending in the direction of the rotation center line X of the main shaft 2. The first rear shoe 8 rotates around the pin 20 along the outer peripheral surface of the workpiece W. Here, it is important that the sliding surface 8a of the first rear shoe 8 is not at the same height as the outer peripheral grinding wheel 11 but at a position shifted such as a position lower than that. This is for avoiding an increase effect when there is a protrusion or the like on the outer peripheral surface of the workpiece W. The first rear shoe 8 may be movable so as to be housed in the shoe holding member 15.

  Further, the base end portion of the second rear shoe 9 is fixed to the base member 16 on the rear side and the upper side of the first rear shoe 8 independently of the rotation operation of the shoe holding member 15. In addition, the sliding surface 9a side of the second rear shoe 9 may be rotatable to such an extent that it can be positioned with respect to the outer peripheral surface of the workpiece W around a pin (not shown). It is important that the position of the second rear shoe 9 is arranged just behind the inner peripheral grinding wheel 12. A hydraulic cylinder, an air cylinder, an electric cylinder, etc. are provided on the base end side of the second rear shoe 9 so that the second rear shoe 9 is in contact with the outer peripheral surface of the workpiece W when the outer peripheral grinding wheel 11 is processed. The position of the surface 9a may be configured to be displaceable.

  On the front side of the base member 16, a rotation actuator 23 is disposed for pressing the pressed portion 15 b extending forward from the shoe holding member 15 to rotate the shoe holding member 15 about the rotation shaft 17. Yes. The rotation actuator 23 is composed of, for example, a hydraulic cylinder, a pneumatic cylinder, an electric cylinder, and the like, and the cylinder portion is fixed to the base member 16 and the rod tip portion contacts the pressed portion 15b of the shoe holding member 15. It is arranged to touch. The shoe holding member 15 is rotated by the expansion / contraction operation of the rotation actuator 23.

  On the front side of the base member 16, two rotation position setting portions 24 that are arranged apart in the vertical direction are provided. These rotation position setting parts 24 serve as stoppers for setting a stop position when the shoe holding member 15 is rotated. That is, a protrusion 15 a is provided at the front end of the shoe holding member 15 so as to protrude to the left side. When the shoe holding member 15 is rotated until the protruding portion 15a comes into contact with the lower rotation position setting portion 24, at this time, as shown in FIG. Is eccentric to the lower side of the rotation center line X of the main shaft 2 and closer to the front shoe 7. For this reason, the second rear shoe 9 fixed to the base member 16 does not contact the outer surface of the workpiece W. The positions of the front shoe 7 and the first rear shoe 8 are positions for outer peripheral surface grinding for grinding the outer peripheral surface of the workpiece W.

  On the other hand, as shown in FIG. 2B, when the shoe holding member 15 is rotated until the protruding portion 15a of the shoe holding member 15 comes into contact with the upper rotation position setting portion 24, the front shoe 7 and the second shoe The position of the rear shoe 9 is a position for inner peripheral surface grinding for grinding the inner peripheral surface of the workpiece W.

  In this way, by providing the rotation actuator 23 and the rotation position setting unit 24 at adjacent positions, the bending moment that can be generated in the shoe holding member 15 when they are separated can be reduced as much as possible. 15 can be prevented from being deformed and can be ground accurately. Here, the “adjacent position” means that the shoe holding member 15 may be separated so as not to generate a large bending moment when pressed by the rotation position setting unit 24 and the pressed portion 15b. means.

  The positions of the front shoe 7, the first rear shoe 8, and the second rear shoe 9 set by the rotation position setting unit 24 may be adjustable depending on the size of the workpiece W, a grinding allowance, and the like.

  Thus, when the grinding apparatus 1 is driven, as shown in FIG. 2A, the center line Y of the workpiece W is below the rotation center line X of the main shaft 2 at the outer peripheral surface grinding position. And, it is eccentric (offset) to the side closer to the front shoe 7. Further, as shown in FIG. 2B, at the position for grinding the inner peripheral surface, the center line Y of the workpiece W is offset above the rotation center line X of the main shaft 2 and closer to the second rear shoe 9. To do. That is, the front shoe 7 and the first rear shoe 8 move in the radial direction of the main shaft 2 simply by rotating the shoe holding member 15, and the eccentric direction of the center line Y of the workpiece W with respect to the rotation center line X of the main shaft 2. Will be switched. On the other hand, since the second rear shoe 9 is in a predetermined position with respect to the base member 16 regardless of the rotation operation of the shoe holding member 15, it moves relative to the first rear shoe 8 to move the shoe. As the holding member 15 rotates, it may or may not come into contact with the outer peripheral surface of the workpiece W.

  The clamp mechanism 18 has a well-known structure that fixes the shoe holding member 15 to the base member 16 by using a frictional force generated by pressing the shoe holding member 15 against the base member 16. . The clamp mechanism 18 includes, for example, a disc spring that urges the shoe holding member 15 in a direction in which the shoe holding member 15 is pressed against the base member 16, and a hydraulic cylinder that prevents the urging force of the disc spring from acting on the shoe holding member 15. A hydraulic clamp can be used.

  The outer peripheral grinding wheel 11 is arranged such that its rotation center line is parallel to the rotation center line X of the main shaft 2 and is located outside the workpiece W at the same height position. The outer peripheral grinding wheel 11 is rotationally driven in a direction indicated by an arrow C in FIG. 2 (a direction opposite to the normal rotation direction A of the main shaft 2) by a driving device (not shown). Further, the inner peripheral surface grinding wheel 12 is arranged so that its rotation center line is parallel to the rotation center line X of the main shaft 2 and is located inside the workpiece W at the same height position. The inner peripheral grinding wheel 12 is driven to rotate in the same direction as the outer peripheral grinding wheel 11 (the direction indicated by the arrow D in FIG. 2B) by a driving device (not shown). Further, the outer peripheral surface grinding wheel 11 and the inner peripheral surface grinding wheel 12 are supported by a movable mechanism (not shown) and are moved in a direction in which they are in contact with and separated from the workpiece W.

  Next, a method for grinding the workpiece W using the grinding apparatus 1 configured as described above will be described.

  First, the case where the outer peripheral surface of the workpiece W is ground will be described. After the clamp mechanism 18 is in an unclamped state and the shoe holding member 15 is free, the rotation actuator 23 is operated to rotate the shoe holding member 15. As shown in FIG. 2A, the front shoe 7, the first rear shoe 8, and the second rear shoe 9 are brought into positions for grinding the outer peripheral surface. Then, the shoe holding member 15 is fixed to the base member 16 with the clamp mechanism 18 in a clamped state. At this time, the second rear shoe 9 is separated from the outer peripheral surface of the workpiece W and does not come into contact therewith.

  In this state, the workpiece W is supported on the front shoe 7 and the first rear shoe 8 and is attracted to the attracting surface 5 c of the electromagnetic chuck 5. Then, by rotating the main shaft 2 in the direction of arrow A, the workpiece W rotates in the same direction while sliding on the sliding surfaces 7a and 8a of the front shoe 7 and the first rear shoe 8. At this time, the center line Y of the workpiece W and the rotation center line X of the spindle 2 are decentered as described above, but the workpiece W is only attracted to the attracting surface 5c of the electromagnetic chuck 5, and therefore the attracting surface 5c. However, it does not move away from the front shoe 7 and the first rear shoe 8.

  Then, the outer peripheral grinding wheel 11 is moved by the movable mechanism while being rotated in the direction of the arrow C by the driving device, and is brought into contact with the outer peripheral surface of the workpiece W. Thereby, the outer peripheral surface of the workpiece W is down-ground over the entire circumference. At this time, since the center line Y of the workpiece W is eccentric to the lower side of the rotation center line X of the main shaft 2 and closer to the first rear shoe 8, the workpiece W includes the front shoe 7 and the first shoe. A pressing force against the rear shoe 8 acts. Thereby, it is possible to grind the workpiece W stably.

  On the other hand, the case where the inner peripheral surface of the workpiece W is ground will be described. The clamp mechanism 18 is brought into an unclamped state while the workpiece W is held by the front shoe 7 and the first rear shoe 8, and then the rotation actuator 23 is moved. By actuating, the shoe holding member 15 is rotated around the rotation shaft 17, and as shown in FIG. 2B, the front shoe 7, the first rear shoe 8, and the second rear shoe 9 are brought into positions for grinding the inner peripheral surface. To do. Then, the shoe holding member 15 is fixed to the base member 16 with the clamp mechanism 18 in a clamped state. By rotating the shoe holding member 15, the sliding surface 9 a of the second rear shoe 9 fixed to the base member 16 pops out and comes into contact with the outer peripheral surface of the workpiece W, and the sliding surface of the first rear shoe 8. There is a gap between 8a and the outer peripheral surface of the workpiece W.

  In this state, the workpiece W supported by the front shoe 7 and the second rear shoe 9 is attracted to the attracting surface 5c of the electromagnetic chuck 5, and the workpiece W is rotated by rotating the spindle 2 in the direction of arrow B. Then, the inner peripheral grinding wheel 12 is moved by the movable mechanism while being rotated by the driving device, and is brought into contact with the inner peripheral surface of the workpiece W. Thereby, the inner peripheral surface of the workpiece W is down-ground over the entire circumference. At this time, since the center line Y of the workpiece W is eccentric above the rotation center line X of the main shaft 2 and closer to the front shoe 7, the workpiece W includes the front shoe 7 and the second rear shoe. The pressing force to 9 acts. Thereby, it is possible to grind the workpiece W stably.

  That is, the shoe moving mechanism 10 presses the positions of the front shoe 7, the first rear shoe 8, and the second rear shoe 9 against the workpiece W against the front shoe 7 and the first rear shoe 8 during grinding of the outer peripheral surface of the workpiece W. A position where the center line Y of the workpiece W is decentered from the rotation center line X of the main shaft 2 so that a force is applied, and when the inner peripheral surface of the workpiece W is ground, the workpiece W is moved to the front shoe 7 and the second rear shoe 9. The center line Y of the workpiece W is switched to a position where it is decentered from the rotation center line X of the main shaft 2 so that the pressing force is applied.

  As described above, according to the grinding apparatus 1 according to this embodiment, the front shoe 7 and the second rear shoe 9 are moved without moving the headstock 3, so the electromagnetic chuck mounted on the main shaft 2. 5 is not displaced, and the machining accuracy of the workpiece W can be improved. Further, by merely rotating the shoe holding member 15 around the rotation shaft 17, the front shoe 7 and the first rear shoe 8 are displaced with respect to the main shaft 2, and the second rear shoe 9 is changed in relative position, so that the workpiece is changed. Since the eccentric direction of W can be easily switched, it is not necessary to provide an actuator for moving any one of the front shoe 7, the first rear shoe 8, and the second rear shoe 9, and the structure and control are simplified.

  In the present embodiment, at the time of machining by the outer peripheral grinding wheel 11, the outer peripheral surface of the workpiece W is supported on the front side by the front shoe 7, and the outer peripheral surface of the workpiece W is opposed to the outer peripheral grinding wheel 11 by the first rear shoe 8. Although supported from the side, the second rear shoe 9 was not brought into contact with the outer peripheral surface of the workpiece. At this time, by supporting the workpiece W by the first rear shoe 8 at a position slightly shifted rather than just behind the outer circumferential grinding wheel 11, an increase in projection when the outer circumferential surface of the workpiece W has a projection is prevented. be able to.

  Further, at the time of processing by the inner peripheral surface grinding wheel 12, the outer peripheral surface of the workpiece W is supported on the front side by the front shoe 7, and the second rear shoe 9 moves relative to the first rear shoe 8 to move the workpiece W. The outer peripheral surface of the inner peripheral surface was supported from directly behind the inner peripheral surface grinding wheel 12. For this reason, the inner peripheral surface of the workpiece can be processed with high accuracy.

  Therefore, by using the first rear shoe 8 and the second rear shoe 9 separately for grinding the outer peripheral surface and the inner peripheral surface of the workpiece W, it is possible to support the workpiece W at an optimum position. it can.

  The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above embodiment, the main shaft 2 is horizontal, but it may be vertical. In that case, the position of the front shoe 7 expressed as the front side and the lower side may be arranged on either the left or right side.

  In order to securely hold the workpiece W, an actuator that moves either the first rear shoe 8 or the second rear shoe 9 exclusively may be provided.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

1 Grinding equipment
2 Spindle
3 headstock
4 Drive unit
5 Electromagnetic chuck
5a Body
5b Backing plate
5c Suction surface
7 Front shoe
7a, 8a, 9a Sliding surface
8 First rear shoe
9 Second rear shoe
10 Shoe movable mechanism
11 outer peripheral grinding wheel
12 Inner surface grinding wheel
15 Shoe holding member
15a protrusion
15b Pressed part
16 Base member
17 Rotating shaft
18 Clamp mechanism
19 pins
20 pins
23 Rotating actuator
24 Rotation position setting part

Claims (4)

In a grinding apparatus for grinding an outer peripheral surface and an inner peripheral surface of an annular workpiece,
The spindle,
A spindle drive unit that switches the spindle to forward and reverse rotation, and
A chuck that is attached to the main shaft and has a suction surface that sucks one end surface in the center line direction so that the center line of the workpiece is parallel to the main shaft;
An outer peripheral grinding wheel that contacts the outer peripheral surface of the workpiece on the front side and grinds the outer peripheral surface;
An inner peripheral grinding wheel that contacts the inner peripheral surface of the workpiece and grinds the inner peripheral surface;
A front shoe for supporting the outer peripheral surface of the workpiece on the front side;
A first rear shoe that is spaced from the outer peripheral surface of the workpiece during machining by the inner peripheral grinding wheel and that supports the outer peripheral surface of the workpiece from the opposite side of the outer peripheral grinding wheel during processing by the outer peripheral grinding wheel; ,
When machining with the outer peripheral grinding wheel, the distance from the outer peripheral surface of the workpiece is increased, and when machining with the inner peripheral grinding wheel, the outer peripheral surface of the workpiece is moved toward the inner surface by moving relative to the first rear shoe. A grinding apparatus comprising: a second rear shoe supported from the opposite side of the circumferential grinding wheel. The grinding apparatus according to claim 1,
The front shoe and the first rear shoe are attached, and a shoe movable mechanism for displacing the front shoe and the first rear shoe with respect to the main shaft,
The shoe moving mechanism is configured to determine the positions of the front shoe and the first rear shoe.
A first centerline of the workpiece is decentered with respect to a rotation centerline of the main shaft so that a pressing force against the front shoe and the first rear shoe is applied to the workpiece during grinding of the outer peripheral surface of the workpiece. location and,
Secondly, the center line of the workpiece is decentered with respect to the rotation center line of the main shaft so that a pressing force against the front shoe and the second rear shoe is applied to the workpiece during grinding of the inner peripheral surface of the workpiece. A grinding apparatus characterized by being configured to switch to a position. The grinding apparatus according to claim 2, wherein
The shoe moving mechanism is
A base member fixed to a headstock for supporting the main shaft and provided with the second rear shoe;
A shoe holding member provided with the front shoe and the first rear shoe, and supported rotatably about a rotation shaft provided on the base member;
A rotation actuator provided on the base member and configured to press and rotate the shoe holding member;
A grinding apparatus, comprising: a rotation position setting portion that is provided on the base member and regulates a rotation range of the shoe holding member pressed by the rotation actuator. The grinding apparatus according to claim 3, wherein
The grinding apparatus according to claim 1, wherein the rotation actuator and the rotation position setting unit are provided at positions adjacent to the rotation axis.

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