Grinder

Abstract

To provide a grinder in which the change of device settings when changing the type of a workpiece being a processing object is easy.SOLUTION: A grinder includes: a pressure rotor 70 that is arranged on the left side relative to a processing position S and presses a workpiece W arranged at the processing position S toward the right side; a pressure rotor receiver 75 that has a rotor holding hole which penetrates in the left-right direction and through which the pressure rotor 70 can be inserted from the left side; a bush receiver 80 that is arranged on the left side relative to the pressure rotor receiver 75, and has a bush holding hole which communicates with the rotor holding hole and through which the pressure rotor can pass; a shoe mounting part 60 that is arranged on the left side of a shoe 65 and supports the shoe 65; a space that is defined by the outer circumferential surface of the pressure rotor 70; a communication passage that directly communicates with the space; and one or more pipe connection parts 15 that are connected to the communication passage. All of the pipe connection parts 15 are disposed on the rear side relative to the pressure rotor receiver 75.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a grinding machine.

Background Art

[0002] Conventionally, a grinding machine has been used for grinding the inner peripheral surface of a cylindrical workpiece (see, for example, Patent Document 1 and Patent Document 2). The grinding machines described in Patent Document 1 and Patent Document 2 include a retracting roll and a supporting roll for rotating the workpiece, a shoe that abuts against the workpiece at its tip to hold the workpiece at the machining position, and a grinding means having a grindstone for grinding the workpiece. Further, this type of grinding machine includes a pressure rotor that abuts against the workpiece at the machining position from the side opposite to the grindstone to restrict displacement of the workpiece during grinding. This pressure rotor retracts and separates from the workpiece when loading and unloading the workpiece to and from the machining position, and advances and abuts against the workpiece when grinding the workpiece. For this reason, around the pressure rotor, there may be provided piping for air for advancing and retracting the pressure rotor, piping for lubricating oil supplied to the pressure rotor, and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, it is necessary to replace the pressure rotor depending on the workpiece to be machined in the above grinding machine. For this reason, in the conventional grinding machine, it is desired to facilitate the change of the apparatus setting when changing the type of workpiece to be machined.

[0005] Therefore, the present invention provides a grinding machine that can easily change the device settings when changing the type of workpiece to be processed.

Means for Solving the Problems

[0006] The grinding machine according to the first aspect of the present invention includes a base, a first roll rotatably supported by the base about a first axis extending in a horizontal first direction, and a second roll rotatably supported by the base about a second axis parallel to the first axis, and configured to rotate the workpiece supplied to a machining position between the first roll in cooperation with the first roll. A shoe disposed on a first side in a horizontal second direction orthogonal to the first direction with respect to the machining position, and contacting the workpiece disposed at the machining position to hold the workpiece at the machining position. A presser rotor disposed on a first side in the first direction with respect to the machining position, and pressing the workpiece disposed at the machining position to the second side in the first direction. A presser rotor receiver supported by the base, having a rotor holding hole formed to penetrate in the first direction and allowing the presser rotor to be inserted from the first side in the first direction, and holding the presser rotor movably in the first direction. A bush receiver supported by the base, disposed on the first side in the first direction with respect to the presser rotor receiver, having a bush holding hole formed to communicate with the rotor holding hole and allowing the presser rotor to pass through. A guide bush inserted into the bush receiver from the first side in the first direction and contacting the presser rotor to define an end portion on the first side in the moving range of the presser rotor in the first direction. A shoe mounting portion disposed on the first side in the first direction with respect to the shoe, supporting the shoe and supported by the base. A space defined by the outer peripheral surface of the presser rotor, a communication passage having a first end portion directly communicating with the space and a second end portion opposite to the first end portion, and one or more pipe connection portions connected to the second end portion of the communication passage. All of the pipe connection portions are disposed on the first side in the second direction with respect to the presser rotor receiver.

[0007] In the first aspect, when replacing the pressure rotor, it is necessary to remove the guide bush from the bush receiver to the first side in the first direction, and further remove the pressure rotor from the pressure rotor receiver to the first side in the first direction through the bush holding hole of the bush receiver. Here, while the pressure rotor receiver and the bush receiver are arranged on the first side in the first direction with respect to the processing position, the shoe and the shoe mounting portion are arranged on the first side in the second direction with respect to the processing position. Therefore, there are no shoes and shoe mounting portions on the second side in the second direction with respect to the processing position, the pressure rotor receiver, and the bush receiver. For this reason, the space on the second side in the second direction with respect to the pressure rotor receiver and the bush receiver can be used as a space for passing the guide bush and the pressure rotor when replacing the pressure rotor. Further, in the first aspect, since the pipe connection portion is arranged on the same side as the shoe and the shoe mounting portion in the second direction with respect to the pressure rotor receiver, it is possible to avoid arranging the pipe connected to the pipe connection portion in the space for passing the guide bush and the pressure rotor when replacing the pressure rotor. Therefore, the workability when replacing the pressure rotor is improved, and the change of the device setting when changing the type of the workpiece to be processed becomes easy.

[0008] The grinding machine according to the second aspect of the present invention is the grinding machine according to the first aspect, further including a bush disposed inside the rotor holding hole and attached to the outer peripheral surface of the pressure rotor, wherein the space includes a forward cylinder chamber that expands when the pressure rotor advances to the second side in the first direction, a backward cylinder chamber that expands when the pressure rotor retreats to the first side in the first direction, and a lubricating oil chamber formed between the bush and the outer peripheral surface of the pressure rotor. The communication passage includes a first communication passage communicating with the forward cylinder chamber, a second communication passage communicating with the backward cylinder chamber, and a third communication passage communicating with the lubricating oil chamber. The pipe connection portion may include a first pipe connection portion connected to the first communication passage, a second pipe connection portion connected to the second communication passage, and a third pipe connection portion connected to the third communication passage.

[0009] According to the second aspect, it is possible to avoid that all of the first pipe connection portion provided for advancing the pressure rotor, the second pipe connection portion provided for retracting the pressure rotor, and the third pipe connection portion for lubricating the sliding portion of the pressure rotor are arranged in the space for passing the guide bush and the pressure rotor. Therefore, the above-described operational effects can be achieved.

[0010] The grinding machine according to the third aspect of the present invention is the grinding machine according to the first aspect or the second aspect, wherein the communication passage may extend from the first end portion to the second end portion without passing through the base.

[0011] According to the third aspect, the structure of the base serving as the mounting reference for each component of the grinding machine can be simplified, and the communication passage can be formed in a member that is easier to form in a smaller size than the base, so that the manufacture of the grinding machine can be facilitated. Further, since the communication passage does not pass through the base, the communication passage does not pass through the joint surface between the base and the members other than the base. Therefore, leakage of the fluid in the communication passage can be suppressed.

[0012] The grinding machine according to the fourth aspect of the present invention is the grinding machine according to any one of the first aspect to the third aspect, wherein at least a part of the communication passage is formed across the shoe mounting portion and the bush receiver, and the shoe mounting portion and the bush receiver may be integrally formed.

[0013] According to the fourth aspect, since the communication passage is formed in a single member including the shoe mounting portion and the bush receiver, the locations where the communication passage passes through the joint surfaces of the members provided separately from each other can be reduced. Therefore, leakage of the fluid in the communication passage can be suppressed.

[0014] The grinding machine according to the fifth aspect of the present invention is the grinding machine according to any one of the first aspect to the fourth aspect, wherein all of the pipe connection portions are fixed to the shoe mounting portion, and the pipe connection portions may be arranged in the second direction when viewed from the vertical direction.

[0015] According to the fifth aspect, the shoe mounting portion can be miniaturized in the first direction. Therefore, when the surface of the shoe mounting portion facing the second side in the first direction is formed flush with the surface of the pressure rotor receiver facing the second side in the first direction, the surface of the pressure rotor receiver facing the second side in the first direction can be arranged at a position farther from the grinding wheel disposed on the second side in the first direction with respect to the pressure rotor receiver. Thereby, the work that can be arranged at the machining position can be made longer. Therefore, the grinding machine can process a wider variety of workpieces.

[0016] The grinding machine according to the sixth aspect of the present invention is the grinding machine according to any one of the first to fifth aspects, further comprising a transfer device for transferring the workpiece to and from the machining position, the transfer device having a holding portion for holding the workpiece, and the holding portion may be formed so as to be displaceable in the first direction at a position on the second side in the second direction with respect to the pressure rotor receiver.

[0017] According to the sixth aspect, as described above, there are no shoes and shoe mounting portions on the second side in the second direction with respect to the machining position, the pressure rotor receiver, and the bush receiver, and further no piping connection portions. Therefore, the transfer device can be arranged closer to the machining position. As a result, the dimensional range of the workpiece that the transfer device can transfer to and from the machining position is widened, so that the grinding machine can process a wider variety of workpieces.

Advantages of the Invention

[0018] According to the present invention, it is possible to provide a grinding machine in which the device settings can be easily changed when changing the type of workpiece to be machined.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a schematic configuration of a grinding machine of the embodiment. As shown in FIG. 1, the grinding machine 1 of the present embodiment is a device that grinds a work W supplied to a predetermined processing position with a grinding wheel T while rotating the work W. In the present embodiment, the grinding machine 1 is an internal grinding machine that grinds the inner surface of a cylindrical work W. Here, the front-rear direction (second direction) and the left-right direction (first direction) are defined as follows. The front-rear direction is the depth direction as viewed from the standing position of the operator, and the +X direction in the figure is the rear (depth side). The left-right direction coincides with the left-right direction as viewed from the standing position of the operator, and the +Z direction in the figure is the right direction. The +Y direction in the figure is the upward direction.

[0021] The grinding machine 1 includes a grinding machine main body 2, a conveying device 3 that conveys the work W, and a bed 4 that supports the grinding machine main body 2 and the conveying device 3. The conveying device 3 is arranged along the front edge of the grinding machine 1. The grinding machine main body 2 is arranged at a position behind the conveying device 3.

[0022] The conveying device 3 conveys the workpiece W along the left - right direction. The conveying device 3 receives the workpiece W from outside the grinding machine 1 and delivers it to the grinding machine main body 2, and receives the processed workpiece W from the grinding machine main body 2 and delivers it to the downstream device. The conveying device 3 includes a holding portion 3a for holding the workpiece W and a linear motion mechanism 3b for moving the holding portion 3a in the left - right direction. The linear motion mechanism 3b is, for example, a mechanism using a ball screw or a mechanism using a pulley and a belt. However, the configuration of the linear motion mechanism 3b is not particularly limited. The holding portion 3a can be displaced in the left - right direction at a position in front of the grinding machine main body 2 by the operation of the linear motion mechanism 3b while holding the workpiece W.

[0023] The grinding machine main body 2 includes a workpiece holding device 6 and a grindstone holding device 8. The workpiece holding device 6 and the grindstone holding device 8 are arranged side by side in the left - right direction when viewed from the front - rear direction. The workpiece holding device 6 is arranged on the left side with respect to the grindstone holding device 8. The workpiece holding device 6 overlaps the movement locus of the holding portion 3a of the conveying device 3 in the front - rear direction in a plan view seen from above.

[0024] The workpiece holding device 6 is placed on an X - axis table provided so as to be linearly movable in the front - rear direction with respect to the bed 4 and is movable in the front - rear direction. The X - axis table is driven in the front - rear direction by a linear motion mechanism using, for example, a ball screw or the like. The workpiece holding device 6 rotates the workpiece W around a rotation axis along the left - right direction while holding the workpiece W to be processed at a position facing the grindstone holding device 8. The grindstone holding device 8 is placed on a Z - axis table provided so as to be linearly movable in the left - right direction with respect to the bed 4 and is movable in the left - right direction. The Z - axis table is driven in the left - right direction by a linear motion mechanism using, for example, a ball screw or the like. The grindstone holding device 8 rotates the grindstone T around a rotation axis along the left - right direction while holding the grindstone T at a position facing the workpiece holding device 6. The grindstone holding device 8 grinds the workpiece W by displacing in the left - right direction and bringing the grindstone T into contact with the workpiece W held by the workpiece holding device 6.

[0025] FIG. 2 is a right - side view of the workpiece holding device of the embodiment. FIG. 3 is a left - side view of the workpiece holding device of the embodiment. As shown in FIGS. 2 and 3, the work holding device 6 includes a spindle unit 10 that rotates a work W at a predetermined machining position S, a displacement drive unit 20 that displaces a part of the members of the spindle unit 10 so as to avoid the work W when the work W at the machining position S is loaded and unloaded, and a rotation drive unit 30 that generates a driving force for rotating the work W and transmits it to the spindle unit 10. The displacement drive unit 20 is disposed behind the spindle unit 10 in a plan view. The rotation drive unit 30 is disposed on the left side of the spindle unit 10 in a plan view.

[0026] As shown in FIG. 2, the spindle unit 10 includes an upper roll 50 (first roll) and a lower roll 55 (second roll) that rotate a work W supplied to the machining position S therebetween, a shoe 65 that abuts against the work W disposed at the machining position S with its tip 67 and holds the work W at the machining position S, and a base 40 that is fixed to the upper surface of the X-axis table and supports each component of the spindle unit 10.

[0027] The upper roll 50 is disposed above the lower roll 55. The upper roll 50 and the lower roll 55 have rotation axes parallel to each other and are disposed so as to rotate on the same plane. The upper roll 50 and the lower roll 55 are formed so as to rotate in the same direction as each other. The upper roll 50 is rotatably supported by a swing lever 21 described later. The lower roll 55 is rotatably supported by the base 40. The upper roll 50 and the lower roll 55 abut against the work W at the machining position S and rotate the work W. Details of the spindle unit 10 will be described later.

[0028] The displacement driving unit 20 includes a swing lever 21 that rotatably supports the upper roll 50, a servo motor 22 that generates a driving force for swinging the swing lever 21, a transmission unit 23 that transmits the driving force of the servo motor 22 to the swing lever 21, and the like. The swing lever 21 is formed to be long along the front-rear direction. An intermediate portion in the front-rear direction of the swing lever 21 is rotatably supported by the base 40 of the main shaft portion 10. The front end portion on the main shaft portion 10 side in the front-rear direction of the swing lever 21 rotatably supports the upper roll 50. A portion of the swing lever 21 on the side opposite to the front end portion with respect to its rotation center is connected to the transmission unit 23 and receives the driving force of the servo motor 22.

[0029] As shown in FIG. 3, the rotation driving unit 30 includes an upper roll pulley 31 connected to the upper roll 50, a lower roll pulley 32 connected to the lower roll 55, a roll motor 33 that generates a driving force for rotating the upper roll 50 and the lower roll 55, a roll belt 34 wound around the rotating shafts of the upper roll pulley 31, the lower roll pulley 32, and the roll motor 33, and a roll motor idler 35 that prevents the roll belt 34 from loosening.

[0030] The upper roll pulley 31 is disposed on the side (left side) opposite to the grindstone holding device 8 in the left-right direction with respect to the upper roll 50. The upper roll pulley 31 is fixed to the upper roll 50 and rotates about the same axis as the upper roll 50. The lower roll pulley 32 is disposed on the side opposite to the grindstone holding device 8 in the left-right direction with respect to the lower roll 55. The lower roll pulley 32 is fixed to the lower roll 55 and rotates about the same axis as the lower roll 55. The upper roll pulley 31, the lower roll pulley 32, the roll motor idler 35, and the roll motor 33 are disposed at the same position in the left-right direction. The roll belt 34 transmits the driving force of the roll motor 33 to the upper roll 50 and the lower roll 55, and rotates the upper roll 50 and the lower roll 55.

[0031] The spindle unit 10 will be described in detail. In the following description, the directions specified on the displacement drive unit 20 side and the opposite side thereof mean the displacement drive unit 20 side (rear side) with respect to the spindle unit 10 in the front-rear direction and the opposite side (front side). Also, in the following description, the directions specified on the grinding wheel holding device 8 side and the opposite side thereof mean the grinding wheel holding device 8 side (right side) with respect to the spindle unit 10 in the left-right direction and the opposite side (left side).

[0032] FIGS. 4 and 5 are perspective views of the work holding device of the embodiment. As shown in FIGS. 4 and 5, the spindle unit 10 includes a base 40, an upper roll 50, a lower roll 55, a shoe mounting portion 60, a shoe 65 (see FIG. 8), a pressure rotor 70, a pressure rotor receiver 75, a bush receiver 80, and a guide bush 85.

[0033] As shown in FIG. 5, the base 40 has a bottom portion 41 fixed to the X-axis table and a support portion 42 coupled from the grinding wheel holding device 8 side to the bottom portion 41 and protruding upward, and is formed in an L shape that opens upward and on the opposite side of the grinding wheel holding device 8 when viewed from the front-rear direction. The base 40 is a single member in which the bottom portion 41 and the support portion 42 are integrally formed.

[0034] The bottom portion 41 is formed in a rectangular shape that extends in the left-right direction with a constant width in plan view. The bottom portion 41 is disposed along the upper surface of the X-axis table. The bottom portion 41 is formed with fastening holes through which fastening members for fastening the base 40 and the X-axis table are inserted.

[0035] The support portion 42 is disposed along the upper surface of the X-axis table. The lower surface of the support portion 42 is flush with the lower surface of the bottom portion 41. The support portion 42 has a front end surface 42a facing the opposite side of the displacement drive unit 20. The front end surface 42a forms the front end portion of the base 40 on the opposite side of the displacement drive unit 20. The front end surface 42a is a plane orthogonal to the front-rear direction. The support portion 42 includes a front half portion 43 including the front end surface 42a and a rear half portion 44 formed on the displacement drive unit 20 side with respect to the front half portion 43.

[0036] The front half 43 is formed in an L-shape that opens upward and toward the grinding wheel holding device 8 when viewed from the front-rear direction and extends in the front-rear direction. The front half 43 includes a lower part 43a and an upper part 43b that continues above the lower part 43a. When viewed from the front-rear direction, the lower part 43a protrudes toward the grinding wheel holding device 8 more than the upper part 43b. The front half 43 includes a first right side surface 43c facing the grinding wheel holding device 8 side in the lower part 43a, a second right side surface 43d facing the grinding wheel holding device 8 side in the upper part 43b, and a stepped surface 43e that connects the upper end of the first right side surface 43c and the lower end of the second right side surface 43d and faces upward. The first right side surface 43c and the second right side surface 43d are planes orthogonal to the left-right direction. The first right side surface 43c forms the right end portion on the grinding wheel holding device 8 side of the base 40. The stepped surface 43e is a plane orthogonal to the up-down direction.

[0037] Figure 6 is a perspective view of the work holding device of the embodiment. As shown in FIG. 6, the rear half 44 extends rearward from the front half 43 and is formed in an L-shape that opens upward and toward the grinding wheel holding device 8 when viewed from the front-rear direction, similar to the front half 43. A shaft support portion 45 that protrudes upward is formed at the upper end portion of the rear half 44. The shaft support portion 45 protrudes above the front half 43. The shaft support portion 45 rotatably supports an intermediate portion in the front-rear direction of the swing lever 21 about an axis extending in the left-right direction.

[0038] As shown in FIGS. 4 and 5, the upper roll 50 is rotatably supported by the swing lever 21 about a first axis P1 extending in the left-right direction. The upper roll 50 is rotatably and vertically swingably supported by the base 40 via the swing lever 21. The upper roll 50 includes a disk-shaped upper roll body 51 and an upper roll shaft portion 52 that extends from the upper roll body 51 to the opposite side of the grinding wheel holding device 8. The upper roll body 51 is located on the grinding wheel holding device 8 side of the base 40. The upper roll shaft portion 52 is rotatably supported by the swing lever 21. An upper roll pulley 31 (see FIG. 3) is integrally and rotatably connected to the upper roll shaft portion 52 on the opposite side of the upper roll body 51 with the swing lever 21 interposed therebetween.

[0039] The lower roll 55 is rotatably supported by the support block 12 about a second axis P2 extending in the left-right direction. The support block 12 is supported by the support portion 42 of the base 40. The support block 12 is disposed on the opposite side of the displacement drive unit 20 with respect to the lower portion 43a of the front half portion 43 of the support portion 42. The support block 12 is disposed along the front end face 42a of the support portion 42 and fastened to the lower portion 43a of the front half portion 43 of the support portion 42. The lower roll 55 is rotatably supported by the base 40 via the support block 12. The lower roll 55 includes a disk-shaped lower roll body 56 and a lower roll shaft portion 57 extending from the lower roll body 56 to the opposite side of the grindstone holding device 8. The lower roll body 56 is in the same position as the upper roll body 51 in the left-right direction. The lower roll body 56 is disposed below the upper roll body 51 when viewed from the left-right direction. The lower roll body 56 approaches and separates from the upper roll body 51 as the upper roll body 51 swings in the vertical direction. The lower roll shaft portion 57 is rotatably supported by the support block 12. A lower roll pulley 32 (see FIG. 3) is integrally rotatably connected to the lower roll shaft portion 57 on the opposite side of the lower roll body 56 with the support block 12 interposed therebetween.

[0040] FIG. 7 is a right side view of the work holding device of the embodiment. As shown in FIG. 7, the upper roll body 51 and the lower roll body 56 form a processing position S of the work W between them. The distance between the upper roll body 51 and the lower roll body 56 is set smaller than the outer diameter of the work W. The processing position S is formed so as to be shifted toward the displacement drive unit 20 side with respect to the center line connecting the axes P1 and P2 of the upper roll body 51 and the lower roll body 56 when viewed from the left - right direction. The work W disposed at the processing position S contacts the outer peripheral surface of the upper roll body 51, the outer peripheral surface of the lower roll body 56, and the tip surface of the shoe 65. The work W is held in contact with the upper roll body 51, the lower roll body 56, and the shoe 65 so as to be sandwiched from three directions orthogonal to the axial direction of the work W. The work W rotates around the third axis P3 along the left - right direction as the upper roll body 51 and the lower roll body 56 rotate in the same direction with each other, being carried along by the upper roll body 51 and the lower roll body 56. When the upper roll body 51 is separated from the lower roll body 56 by the operation of the displacement drive unit 20, the work W can move from the processing position S to the side opposite to the displacement drive unit 20, and the work W can be transferred to and from the processing position S by the transfer device 3.

[0041] As shown in FIG. 6, the shoe mounting portion 60 is formed in a block shape and is supported by the support portion 42 of the base 40. The shoe mounting portion 60 is fixed to the upper portion 43b of the front half portion 43 of the support portion 42. The shoe mounting portion 60 is arranged along the second right side surface 43d of the front half portion 43 of the support portion 42 and is fastened to the upper portion 43b of the front half portion 43. The shoe mounting portion 60 is arranged above the stepped surface 43e of the front half portion 43 of the support portion 42 and is in contact with the stepped surface 43e. The shoe mounting portion 60 protrudes toward the grinding wheel holding device 8 side more than the first right side surface 43c of the front half portion 43 of the support portion 42. The shoe mounting portion 60 has a shoe mounting surface 61 facing the grinding wheel holding device 8 side. The shoe mounting surface 61 is a plane orthogonal to the left - right direction. The shoe mounting surface 61 is the end portion of the shoe mounting portion 60 on the grinding wheel holding device 8 side. The shoe mounting surface 61 is located on the side opposite to the grinding wheel holding device 8 with respect to the upper roll body 51 and the lower roll body 56. Thereby, the shoe mounting portion 60 does not overlap the upper roll body 51 and the lower roll body 56 in the direction orthogonal to the left - right direction.

[0042] The shoe 65 is supported by the shoe mounting portion 60 and is disposed on the side of the displacement driving portion 20 with respect to the machining position S of the workpiece W. The shoe 65 is disposed on the side of the grindstone holding device 8 with respect to the shoe mounting portion 60. The shoe 65 is in the same position as the upper roll body 51 and the lower roll body 56 in the left-right direction. The shoe 65 has a base portion 66 fixed to the shoe mounting portion 60 and a tip portion 67 that contacts the workpiece W at the machining position S. The base portion 66 is disposed along the shoe mounting surface 61 of the shoe mounting portion 60 and is fastened to the shoe mounting portion 60. The shoe 65 projects from the base portion 66 to the opposite side of the displacement driving portion 20. The tip portion 67 is the end portion of the shoe 65 on the opposite side of the displacement driving portion 20. The tip portion 67 slidably abuts against the workpiece W at the machining position S from the side of the displacement driving portion 20. Thereby, the shoe 65 presses the workpiece W at the machining position S toward the upper roll body 51 and the lower roll body 56 side, and holds the workpiece W at the machining position S in cooperation with the upper roll body 51 and the lower roll body 56.

[0043] Figure 8 is a perspective view showing a state in which the upper roll and the lower roll are removed from the workpiece holding device shown in FIG. 4. FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 8. As shown in FIGS. 8 and 9, the pressure rotor 70, the pressure rotor receiver 75, the bush receiver 80, and the guide bush 85 constitute an air cylinder having the pressure rotor receiver 75, the bush receiver 80, and the guide bush 85 as the cylinder body and the pressure rotor 70 as the piston.

[0044] ​The pressure rotor 70 is disposed on the side opposite to the grindstone holding device 8 with respect to the machining position S. The pressure rotor 70 has a rotating body shape coaxial with the rotation center (third axis P3) of the workpiece W at the machining position S. In the present embodiment, the pressure rotor 70 is formed in a cylindrical shape and has an inner flange 71 that projects radially inward from the opening edge on the machining position S side. The inner flange 71 contacts the edge of the workpiece W from the side opposite to the grindstone holding device 8. The outer peripheral surface of the pressure rotor 70 has an outer flange 72 at the intermediate portion in the left-right direction. The outer flange 72 projects radially outward and extends continuously over the entire circumference around the pressure rotor 70. In the following description, the portion of the outer peripheral surface of the pressure rotor 70 on the machining position S side with respect to the outer flange 72 is referred to as the right half portion 73. The right half portion 73 extends in the left-right direction with a constant outer diameter. The pressure rotor 70 is rotatably supported by a pressure rotor receiver 75.

[0045] The pressure rotor receiver 75 is disposed on the side opposite to the displacement drive unit 20 with respect to the shoe mounting portion 60. The pressure rotor receiver 75 is disposed so as to overlap the front surface facing the side opposite to the displacement drive unit 20 in the shoe mounting portion 60. The pressure rotor receiver 75 is formed in a rectangular shape extending in the front-rear direction as viewed from the left-right direction. The pressure rotor receiver 75 has a constant thickness in the left-right direction. The pressure rotor receiver 75 has a right side surface 75a facing the grindstone holding device 8 side. The right side surface 75a is a plane orthogonal to the left-right direction. The right side surface 75a is flush with the shoe mounting surface 61 of the shoe mounting portion 60.

[0046] The pressure rotor receiver 75 is formed with a rotor holding hole 76 penetrating in the left - right direction. The rotor holding hole 76 has a circular cross - sectional shape centered on the third axis P3. A pressure rotor 70 is inserted into the rotor holding hole 76 from the side opposite to the grindstone holding device 8. The inner surface of the rotor holding hole 76 includes a small - diameter portion 76a extending from the opening edge on the grindstone holding device 8 side in the rotor holding hole 76 to the side opposite to the grindstone holding device 8 with a constant inner diameter, a large - diameter portion 76b extending from the opening edge on the side opposite to the grindstone holding device 8 in the rotor holding hole 76 to the grindstone holding device 8 side with a constant inner diameter larger than that of the small - diameter portion 76a, and a step portion 76c extending radially outward from the edge on the side opposite to the grindstone holding device 8 in the small - diameter portion 76a and connecting to the edge on the grindstone holding device 8 side in the large - diameter portion 76b. The outer flange 72 of the pressure rotor 70 is disposed inside the large - diameter portion 76b. The outer peripheral surface of the outer flange 72 is in sliding contact over the entire circumference in the large - diameter portion 76b. The step portion 76c faces the outer flange 72. The step portion 76c has a gap in the left - right direction with respect to the outer flange 72. A cylindrical static pressure bush 78 is inserted inside the small - diameter portion 76a. The static pressure bush 78 is mounted on the right - hand half 73 of the outer peripheral surface of the pressure rotor 70. The pressure rotor receiver 75 holds the pressure rotor 70 via the static pressure bush 78 so as to be displaceable in the left - right direction.

[0047] As shown in FIG. 9, the hydrostatic bush 78 is formed in a cylindrical shape coaxial with the pressure rotor 70. The hydrostatic bush 78 includes an outer peripheral groove 78a formed on the outer peripheral surface and an inner peripheral groove 78b formed on the inner peripheral surface. The outer peripheral groove 78a extends over the entire circumference with a constant width. The outer peripheral groove 78a is defined by the small-diameter portion 76a of the inner surface of the rotor holding hole 76 from the outer side in the radial direction. A pair of inner peripheral grooves 78b are provided at intervals in the left-right direction. Each inner peripheral groove 78b extends over the entire circumference with a constant width. The formation range of each inner peripheral groove 78b in the left-right direction is within the formation range of the outer peripheral groove 78a in the left-right direction. Each inner peripheral groove 78b is defined by the right half portion 73 of the outer peripheral surface of the pressure rotor 70 from the inner side in the radial direction. The pair of inner peripheral grooves 78b communicate with each other through a slight gap between the inner peripheral surface of the hydrostatic bush 78 and the right half portion 73 of the outer peripheral surface of the pressure rotor 70. The pair of inner peripheral grooves 78b communicate with the outer peripheral groove 78a through a through hole (partially not shown) that penetrates the hydrostatic bush 78 in the radial direction.

[0048] As shown in FIGS. 5 and 8, the bush receiver 80 is disposed on the side opposite to the machining position S with respect to the pressure rotor receiver 75 and is arranged side by side with the pressure rotor receiver 75 in the left-right direction. The bush receiver 80 is fastened to the pressure rotor receiver 75. Thereby, the pressure rotor receiver 75 is supported by the base 40 via the bush receiver 80 and the shoe mounting portion 60. The right side surface of the bush receiver 80 on the machining position S side is in surface contact with the left side surface of the pressure rotor receiver 75 facing the side opposite to the machining position S, and they are joined under the fastening force between the bush receiver 80 and the pressure rotor receiver 75.

[0049] The bush receiver 80 is disposed on the side opposite to the displacement drive unit 20 with respect to the shoe attachment part 60. The bush receiver 80 is fixed to the shoe attachment part 60. The bush receiver 80 is integrally formed with the shoe attachment part 60. That is, the bush receiver 80 and the shoe attachment part 60 are a single member. The left side surface of the bush receiver 80 facing the opposite side of the processing position S is flush with the left side surface of the shoe attachment part 60 facing the opposite side of the grindstone holding device 8. The bush receiver 80 protrudes on the side opposite to the displacement drive unit 20 from the front end surface 42a of the support part 42 of the base 40. Thereby, a space where the base 40 does not exist is formed on the side opposite to the grindstone holding device 8 with respect to the bush receiver 80.

[0050] As shown in FIG. 9, a bush holding hole 81 communicating with the rotor holding hole 76 is formed in the bush receiver 80. The bush holding hole 81 penetrates the bush receiver 80 in the left-right direction. The bush holding hole 81 has a circular cross-sectional shape and is formed coaxially with the rotor holding hole 76. The inner surface of the bush holding hole 81 extends in the left-right direction with a substantially constant inner diameter. The inner diameter of the bush holding hole 81 is larger than the outer diameter of the pressure rotor 70 throughout. Thereby, the pressure rotor 70 can pass through the bush holding hole 81.

[0051] As shown in FIGS. 5 and 9, the guide bush 85 is inserted into the bush holding hole 81 from the side opposite to the pressure rotor receiver 75. The guide bush 85 can contact the pressure rotor 70 from the side opposite to the processing position S. The guide bush 85 has a rotating body shape coaxial with the bush holding hole 81 of the bush receiver 80. In the present embodiment, the guide bush 85 is formed in a columnar shape having a through hole at the center. The guide bush 85 includes a small diameter part 86 formed on the pressure rotor receiver 75 side with respect to the intermediate part in the left-right direction, and a large diameter part 88 adjacent to the small diameter part 86 on the side opposite to the pressure rotor receiver 75.

[0052] As shown in FIG. 9, the small-diameter portion 86 includes an outer peripheral surface 86a and an end surface 86b facing the pressure rotor receiver 75 side. The outer peripheral surface 86a has a radial gap over the entire circumference with respect to the inner surface of the bush holding hole 81. The end surface 86b faces the left side surface of the pressure rotor receiver 75 and the outer flange 72 of the pressure rotor 70. The end surface 86b has a gap in the left-right direction with respect to the pressure rotor receiver 75 and the outer flange 72. A recess 87 that opens toward the pressure rotor 70 is formed at the center of the end surface 86b. An end portion on the opposite side of the machining position S in the pressure rotor 70 is inserted into the recess 87. The opening edge 87a of the recess 87 protrudes toward the pressure rotor 70 over the entire circumference and abuts against the outer flange 72 of the pressure rotor 70 from the opposite side of the machining position S.

[0053] The large-diameter portion 88 is inserted into the bush holding hole 81 such that the end portion on the opposite side of the pressure rotor 70 protrudes from the bush receiver 80 to the opposite side of the pressure rotor 70. The outer peripheral surface of the large-diameter portion 88 is in sliding contact with the inner surface of the bush holding hole 81 over the entire circumference. The large-diameter portion 88 includes a flange portion 89. The flange portion 89 is provided at the end portion on the opposite side of the pressure rotor 70 in the large-diameter portion 88. The flange portion 89 protrudes outward in the radial direction and extends over the entire circumference of the guide bush 85. The flange portion 89 abuts against the opening edge on the opposite side of the pressure rotor receiver 75 in the bush receiver 80. A retaining member (not shown) abuts against the guide bush 85 from the opposite side of the pressure rotor 70. The retaining member is displaceably attached to the bush receiver 80. By moving the retaining member from the position where it abuts against the guide bush 85, the guide bush 85 can be moved to the opposite side of the pressure rotor 70, and thus it can be removed from the bush receiver 80.

[0054] The left - right movement range of the pressure rotor 70 is defined by the contact of the pressure rotor 70 with other members. The end on the machining position S side within the movement range of the pressure rotor 70 is the position where the outer flange 72 contacts the stepped portion 76c on the inner surface of the rotor holding hole 76 of the pressure rotor receiver 75. The end on the side opposite to the machining position S within the movement range of the pressure rotor 70 is the position where the outer flange 72 contacts the opening edge 87a of the recess 87 of the guide bush 85.

[0055] FIG. 10 is a perspective view showing the communication passage in the work holding device of the embodiment. As shown in FIGS. 9 and 10, the main shaft portion 10 includes a cylinder inner space 90, a communication passage 95, and a pipe connection portion 15.

[0056] The cylinder inner space 90 is defined by the outer peripheral surface of the pressure rotor 70. The cylinder inner space 90 has a forward cylinder chamber 91 that expands when the pressure rotor 70 advances toward the machining position S, a backward cylinder chamber 92 that expands when the pressure rotor 70 retreats to the side opposite to the machining position S, and a lubricating oil chamber 93 formed between the static pressure bush 78 and the outer peripheral surface of the pressure rotor 70.

[0057] The forward cylinder chamber 91 is a space defined by the left end surface of the outer flange 72 of the pressure rotor 70 facing the side opposite to the machining position S. Specifically, the forward cylinder chamber 91 includes a first annular space between the outer peripheral surface 86a of the small - diameter portion 86 of the guide bush 85 and the inner surface of the bush holding hole 81 of the bush receiver 80, and a second annular space between the end surface 86b of the small - diameter portion 86 of the guide bush 85, the left side surface of the pressure rotor receiver 75, and the outer flange 72 of the pressure rotor 70. The radially outer end of the second annular space communicates with the end on the pressure rotor receiver 75 side in the first annular space.

[0058] The cylinder chamber 92 for retraction is a space defined by the right end face facing the machining position S side on the outer flange 72 of the pressure rotor 70. Specifically, the cylinder chamber 92 for retraction is a gap between the outer flange 72 of the pressure rotor 70, the stepped portion 76c on the inner surface of the rotor holding hole 76 of the pressure rotor receiver 75, and the end face of the hydrostatic bush 78 facing the side opposite to the machining position S.

[0059] The lubricating oil chamber 93 is a space defined by the right half portion 73 of the outer peripheral surface of the pressure rotor 70. Specifically, the lubricating oil chamber 93 is the pair of inner peripheral grooves 78b of the hydrostatic bush 78. Since the pair of inner peripheral grooves 78b communicate with each other through the through hole and the outer peripheral groove 78a, in this embodiment, it is regarded as a single space.

[0060] The communication passages 95 are provided one by one for each cylinder inner space 90. Each communication passage 95 has a first end portion directly communicating with the cylinder inner space 90 and a second end portion on the side opposite to the first end portion. The communication passage 95 includes a first communication passage 96 communicating with the forward cylinder chamber 91, a second communication passage 97 communicating with the retraction cylinder chamber 92, and a third communication passage 98 communicating with the lubricating oil chamber 93.

[0061] The first communication passage 96 has a first end portion 96a opening on the inner surface of the bush holding hole 81 of the bush receiver 80. The first communication passage 96 communicates with the forward cylinder chamber 91 through the first end portion 96a. The first communication passage 96 includes a first portion extending from the first end portion 96a toward the displacement drive unit 20 side of the bush receiver 80 and the shoe mounting portion 60, a second portion extending from the first portion toward the grinding wheel holding device 8 side of the shoe mounting portion 60, and a third portion extending upward from the second portion of the shoe mounting portion 60 to reach the second end portion 96b. The second end portion 96b opens on the upper surface of the shoe mounting portion 60 facing upward.

[0062] The second communication passage 97 has a first end portion 97a that opens to a stepped portion 76c on the inner surface of the rotor holding hole 76 of the pressure rotor receiver 75. The second communication passage 97 communicates with the retraction cylinder chamber 92 through the first end portion 97a. The second communication passage 97 includes a first portion that extends from the first end portion 97a toward the grindstone holding device 8 side of the pressure rotor receiver 75, a second portion that extends from the first portion toward the displacement drive unit 20 side of the pressure rotor receiver 75, a third portion that extends from the second portion toward the opposite side of the grindstone holding device 8 of the pressure rotor receiver 75 and the bush receiver 80, a fourth portion that extends from the third portion toward the displacement drive unit 20 side of the bush receiver 80 and the shoe mounting portion 60, a fifth portion that extends from the fourth portion toward the grindstone holding device 8 side of the shoe mounting portion 60, and a sixth portion that extends upward from the fifth portion to reach the second end portion 97b. The sixth portion is formed on the displacement drive unit 20 side with respect to the second portion of the first communication passage 96 and overlaps the third portion of the first communication passage 96 when viewed from the front-rear direction. The second end portion 97b is aligned with the second end portion 96b of the first communication passage 96 in the front-rear direction and is formed on the opposite side of the displacement drive unit 20 with respect to the second end portion 96b of the first communication passage 96.

[0063] The third communication passage 98 has a first end portion 98a that opens to a small-diameter portion 76a on the inner surface of the rotor holding hole 76 of the pressure rotor receiver 75. The third communication passage 98 communicates with the lubricating oil chamber 93 through the first end portion 98a. The third communication passage 98 includes a first portion that extends downward from the first end portion 98a through the pressure rotor receiver 75, a second portion that extends from the first portion toward the displacement drive unit 20 side through the pressure rotor receiver 75, a third portion that extends from the second portion toward the side opposite to the grindstone holding device 8 through the pressure rotor receiver 75 and the bush receiver 80, a fourth portion that extends from the third portion toward the displacement drive unit 20 side through the bush receiver 80 and the shoe attachment portion 60, a fifth portion that extends from the fourth portion toward the grindstone holding device 8 side through the shoe attachment portion 60, and a sixth portion that extends upward from the fifth portion through the shoe attachment portion 60 to reach a second end portion 98b. The sixth portion is formed on the side opposite to the displacement drive unit 20 with respect to the third portion of the first communication passage 96 and overlaps the third portion of the first communication passage 96 when viewed from the front-rear direction. The second end portion 98b is aligned with the second end portion 97b of the second communication passage 97 in the front-rear direction and is formed on the side opposite to the displacement drive unit 20 with respect to the second end portion 97b of the second communication passage 97.

[0064] As shown in FIGS. 8 and 10, the pipe connection portion 15 is attached to the shoe attachment portion 60 and connected to the second end portion of each communication passage 95. The pipe connection portion 15 is a member that is connected to the pipe outside the shoe attachment portion 60 and communicates the communication passage 95 with the pipe. The pipe is connected to a supply source of air or lubricating oil. The pipe is, for example, a flexible resin pipe or a rigid metal pipe. The pipe connection portion 15 includes a first pipe connection portion 16 connected to the first communication passage 96, a second pipe connection portion 17 connected to the second communication passage 97, and a third pipe connection portion 18 connected to the third communication passage 98. The first pipe connection portion 16 is connected to the second end portion 96b of the first communication passage 96. The second pipe connection portion 17 is connected to the second end portion 97b of the second communication passage 97. The third pipe connection portion 18 is connected to the second end portion 98b of the third communication passage 98. Each pipe connection portion 15 projects upward from the upper surface of the shoe attachment portion 60. Each pipe connection portion 15 is fixed to the shoe attachment portion 60 so that the pipe extends in a direction away from the pressure rotor receiver 75 from the pipe connection portion 15. For example, each pipe is disposed on the right side of the displacement drive portion 20. The pipe connection portions 15 are arranged in the front-rear direction in plan view corresponding to the arrangement of the second end portions of the communication passages 95.

[0065] As shown in FIG. 9, when a gas such as air is introduced into the forward cylinder chamber 91 through the first pipe connection portion 16 and the first communication passage 96, the outer flange 72 of the pressure rotor 70 is pressed toward the machining position S due to the increase in the internal pressure of the forward cylinder chamber 91. When the outer flange 72 is pressed toward the machining position S, the second annular space of the forward cylinder chamber 91 expands and the backward cylinder chamber 92 contracts. As a result, the pressure rotor 70 presses the workpiece W disposed at the machining position S toward the grindstone holding device 8. For example, the pressure rotor 70 presses the workpiece W toward the grindstone holding device 8 when bringing the grindstone T into contact with the workpiece W.

[0066] When a gas such as air is introduced into the retraction cylinder chamber 92 through the second pipe connection portion 17 and the second communication passage 97, the outer flange 72 of the pressure rotor 70 is pressed to the opposite side of the machining position S due to the increase in the internal pressure of the retraction cylinder chamber 92. When the outer flange 72 is pressed to the opposite side of the machining position S, the retraction cylinder chamber 92 expands, and the second annular space of the forward cylinder chamber 91 contracts. As a result, the pressure rotor 70 retracts to the opposite side of the grindstone holding device 8 so as to be separated from the workpiece W disposed at the machining position S. For example, the pressure rotor 70 retracts from the machining position S when loading and unloading the workpiece W to and from the machining position S.

[0067] The grinding machine 1 of the present embodiment described above includes a shoe 65 disposed on the displacement drive unit 20 side with respect to the machining position S, a pressure rotor 70 disposed on the opposite side of the grindstone holding device 8 with respect to the machining position S, a pressure rotor receiver 75 that holds the pressure rotor 70, a bush receiver 80 disposed on the opposite side of the machining position S with respect to the pressure rotor receiver 75, a guide bush 85 inserted into the bush receiver 80 from the opposite side of the machining position S, and a shoe mounting portion 60 disposed on the opposite side of the grindstone holding device 8 with respect to the shoe 65 and supporting the shoe 65. In this configuration, when replacing the pressure rotor 70, it is necessary to extract the guide bush 85 from the bush receiver 80 to the opposite side of the machining position S, and further extract the pressure rotor 70 from the pressure rotor receiver 75 to the opposite side of the machining position S through the bush holding hole 81 of the bush receiver 80. Here, the pressure rotor receiver 75 and the bush receiver 80 are disposed on the left side with respect to the machining position S, while the shoe 65 and the shoe mounting portion 60 are disposed behind the machining position S. Therefore, the shoe 65 and the shoe mounting portion 60 do not exist in front of the machining position S, the pressure rotor receiver 75, and the bush receiver 80. For this reason, the space in front of the pressure rotor receiver 75 and the bush receiver 80 can be used as a space for passing the guide bush 85 and the pressure rotor 70 when replacing the pressure rotor 70.

[0068] Furthermore, in the present embodiment, since all of the pipe connection portions 15 are arranged on the same side as the shoe 65 and the shoe mounting portion 60 in the front-rear direction with respect to the pressure rotor receiver 75, it is possible to avoid arranging the pipes connected to the pipe connection portions 15 in the space through which the guide bush 85 and the pressure rotor 70 pass when replacing the pressure rotor 70. Therefore, the workability when replacing the pressure rotor 70 is improved, and the change of the apparatus setting when changing the type of the workpiece W to be processed becomes easy.

[0069] Also, the grinding machine 1 includes a forward cylinder chamber 91 that expands when the pressure rotor 70 moves forward, a backward cylinder chamber 92 that expands when the pressure rotor 70 moves backward, and a lubricating oil chamber 93 formed between the bush 78 and the outer peripheral surface of the pressure rotor 70. The pipe connection portion 15 has a first pipe connection portion 16 connected to a first communication passage 96 communicating with the forward cylinder chamber 91, a second pipe connection portion 17 connected to a second communication passage 97 communicating with the backward cylinder chamber 92, and a third pipe connection portion 18 connected to a third communication passage 98 communicating with the lubricating oil chamber 93. According to this configuration, it is possible to avoid arranging all of the first pipe connection portion 16 provided for moving the pressure rotor 70 forward, the second pipe connection portion 17 provided for moving the pressure rotor 70 backward, and the third pipe connection portion 18 for lubricating the sliding portion of the pressure rotor 70 in the space through which the guide bush 85 and the pressure rotor 70 pass. Therefore, the above-described operational effects can be achieved.

[0070] Furthermore, all of the first pipe connection portion 16, the second pipe connection portion 17, and the third pipe connection portion 18 are provided on the same surface (upper surface) of the shoe mounting portion 60. Therefore, the workability when connecting or disconnecting the pipes to / from each pipe connection portion 15 can be improved.

[0071] Each communication passage 95 extends from a first end communicating with the space 90 inside the cylinder to a second end without passing through the base 40. According to this configuration, the structure of the base 40, which is the mounting reference for each component of the grinding machine 1, can be simplified, and communication passages 95 can be formed in members (in this embodiment, the shoe mounting portion 60, the pressure rotor receiver 75, and the bush receiver 80) that are easier to form in a smaller size than the base 40, so that the manufacture of the grinding machine 1 can be facilitated. Further, since the communication passage 95 does not pass through the base 40, the communication passage 95 does not pass through the joint surface between the base 40 and members other than the base 40. Therefore, leakage of the fluid in the communication passage 95 can be suppressed.

[0072] Each communication passage 95 is formed across the shoe mounting portion 60 and the bush receiver 80. The shoe mounting portion 60 and the bush receiver 80 are integrally formed. According to this configuration, since the communication passage 95 is formed in a single member including the shoe mounting portion 60 and the bush receiver 80, the locations where the communication passage 95 passes through the joint surfaces of members provided separately from each other can be reduced. Therefore, leakage of the fluid in the communication passage 95 can be suppressed. In this embodiment, since the first communication passage 96 does not pass through the joint surface between members provided separately from each other, leakage of the fluid in the first communication passage 96 can be effectively suppressed.

[0073] All of the pipe connection parts 15 are fixed to the shoe mounting part 60. The pipe connection parts 15 are arranged in the front-rear direction when viewed from the up-down direction. Here, when the shoe mounting surface 61 of the shoe mounting part 60 is flush with the right side surface 75a of the pressure rotor receiver 75, the closer the shoe mounting surface 61 of the shoe mounting part 60 is to the grinding wheel holding device 8, the closer the right side surface 75a of the pressure rotor receiver 75 is to the grinding wheel holding device 8. In order to avoid the work W interfering with the grinding wheel holding device 8 when the work holding device 6 is displaced in the front-rear direction, the closer the right side surface 75a of the pressure rotor receiver 75 is to the grinding wheel holding device 8, the shorter the length of the work W that the main shaft part 10 can hold. According to the present embodiment, the shoe mounting part 60 can be miniaturized in the left-right direction. Therefore, it is possible to arrange the right side surface 75a of the pressure rotor receiver 75 formed flush with the shoe mounting surface 61 of the shoe mounting part 60 at a position farther from the grinding wheel holding device 8, and the work W that can be arranged at the machining position S can be made longer. Therefore, the types of work W that the grinding machine 1 can process can be diversified.

[0074] The transfer device 3 is formed so as to be displaceable in the left-right direction at a position on the opposite side of the displacement drive part 20 from the pressure rotor receiver 75 while holding the work W. According to this configuration, as described above, there are no shoes 65 and shoe mounting parts 60 on the opposite side of the displacement drive part 20 with respect to the machining position S, the pressure rotor receiver 75, and the bush receiver 80, and furthermore, there is no pipe connection part 15. Therefore, the transfer device 3 can be arranged closer to the machining position S. As a result, the dimensional range of the work W that the transfer device 3 can transfer to and receive from the machining position S is widened, so the types of work W that the grinding machine 1 can process can be diversified.

[0075] Note that the present invention is not limited to the above-described embodiment described with reference to the drawings, and various modifications can be considered within its technical scope. For example, in the above-described embodiment, the grinding machine 1 is an internal grinding machine that grinds the inner surface of the work W, but the present invention may also be applied to an external grinding machine that grinds the outer peripheral surface of the work.

[0076] In the above-described embodiment, three pipe connection parts are provided, but the number of pipe connection parts is not particularly limited. For example, the third pipe connection part related to lubricating oil may be omitted.

[0077] In the above-described embodiment, the pipe connection parts 15 are provided side by side in the front-rear direction on the upper surface of the shoe mounting part 60, but the pipe connection parts do not have to be arranged side by side in the front-rear direction. Also, the pipe connection parts do not have to be provided on the upper surface of the shoe mounting part 60.

[0078] In the above-described embodiment, the shoe mounting part 60 and the bush receiver 80 are integrally formed, but the present invention is not limited to this configuration. That is, the shoe mounting part and the bush receiver may be separate from each other. However, it is desirable that the shoe mounting part and the bush receiver be provided as separate members from the base.

[0079] In the above-described embodiment, the shoe mounting surface 61 of the shoe mounting part 60 is flush with the right side surface 75a of the pressure rotor receiver 75, but the present invention is not limited to this configuration. The shoe mounting surface may be on the side of the grindstone holding device with respect to the right side surface of the pressure rotor receiver.

[0080] In addition, within the scope not departing from the gist of the present invention, it is possible to appropriately replace the components in the above-described embodiment with well-known components, and the above-described embodiment and each modification example may be appropriately combined.

Explanation of Reference Numerals

[0081] 1…Grinding machine 3…Conveyor 3a…Holding part 15…Pipe connection part 16…First pipe connection part 17…Second pipe connection part 18…Third pipe connection part 40…Base 60…Shoe mounting part 65…Shoe 70…Pressure rotor 75…Pressure rotor receiver 76…Rotor holding hole 78…Hydrostatic bush (bush) 80…Bush receiver 81…Bush holding hole 85…Guide bush 90…Cylinder inner space (space) 91…Forward cylinder chamber 92…Backward cylinder chamber 93…Lubricating oil chamber 95…Communication passage 96…First communication passage 97…Second communication passage 98…Third communication passage P1…First axis P2…Second axis S…Machining position W…Workpiece

Claims

1. A base, a first roll rotatably supported on the base about a first axis extending in a horizontal first direction, a second roll rotatably supported on the base about a second axis parallel to the first axis, and configured to rotate the workpiece supplied to a machining position between the second roll and the first roll in cooperation with the first roll, a shoe disposed on a first side of a horizontal second direction orthogonal to the first direction with respect to the machining position, and configured to abut against the workpiece disposed at the machining position to hold the workpiece at the machining position, a pressure roller disposed on a first side of the first direction with respect to the machining position, and configured to press the workpiece disposed at the machining position toward a second side of the first direction, a pressure roller receiver supported by the base, having a rotor holding hole formed therethrough in the first direction and allowing the pressure roller to be inserted from the first side in the first direction, and configured to hold the pressure roller movably in the first direction, a bush receiver supported by the base, disposed on the first side of the first direction with respect to the pressure roller receiver, having a bush holding hole formed therein communicating with the rotor holding hole and allowing the pressure roller to pass therethrough, a guide bush inserted into the bush receiver from the first side in the first direction and configured to abut against the pressure roller to define an end on the first side in a movement range of the pressure roller in the first direction, a shoe mounting portion disposed on the first side of the first direction with respect to the shoe, supporting the shoe, and supported by the base, a space defined by an outer peripheral surface of the pressure roller, a communication passage having a first end communicating directly with the space and a second end opposite to the first end, one or more pipe connection portions connected to the second end of the communication passage, comprising, all of the pipe connection portions being disposed on the first side of the second direction with respect to the pressure roller receiver, a grinding machine.

2. further comprising a bush disposed inside the rotor holding hole and mounted on the outer peripheral surface of the pressure roller, the space includes, a forward cylinder chamber that expands when the pressure roller advances toward the second side in the first direction, a backward cylinder chamber that expands when the pressure roller retreats toward the first side in the first direction, a lubricating oil chamber formed between the bush and the outer peripheral surface of the pressure roller, having, said communication passageway is a first communication passageway communicating with said forward cylinder chamber, a second communication passageway communicating with said backward cylinder chamber, a third communication passageway communicating with said lubricating oil chamber, having, said pipe connection portion is a first pipe connection portion connected to said first communication passageway, a second pipe connection portion connected to said second communication passageway, a third pipe connection portion connected to said third communication passageway, having, the grinding machine according to claim 1.

3. said communication passageway extends from said first end portion to said second end portion without passing through said base, the grinding machine according to claim 1 or claim 2.

4. at least a part of said communication passageway is formed across said shoe mounting portion and said bush receiver, said shoe mounting portion and said bush receiver are integrally formed, the grinding machine according to claim 3.

5. all of said pipe connection portions are fixed to said shoe mounting portion, said pipe connection portions are arranged in said second direction as viewed from the vertical direction, the grinding machine according to claim 1 or claim 2.

6. further comprising a transfer device for transferring said workpiece to and from said machining position, said transfer device has a holding portion for holding said workpiece, said holding portion is formed to be displaceable in said first direction at a position on a second side in said second direction from said pressure rotor receiver, the grinding machine according to claim 1 or claim 2.

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