HONING DEVICE

Abstract

A honing device includes a honing tool, a rotating main shaft to which the honing tool is fixed, an axial direction driver to cause the rotating main shaft to move in the Z-axis direction, a workpiece holder to hold a workpiece while a central axis of a processed hole of the workpiece and the a central axis of the rotating main shaft coincide with each other, and a holder drive unit to, by exerting a driving force on a portion of the workpiece holder corresponding to a point on an extension line of the central axis of the rotating main shaft in a direction along the central axis, cause the workpiece holder to move in a direction along the central axis.

Claims

1. A honing device comprising: a honing tool to a tip portion of which a grindstone is disposed; a main shaft having a long length and to which the honing tool is fixed while a tip portion of the honing tool extends from one end side in a longitudinal direction of the main shaft; a rotation driver to cause the main shaft to rotate about a first rotational axis that is along a longitudinal direction of the main shaft; an axial direction driver to cause the main shaft to move in a first direction that is along the first rotational axis; a workpiece holder to hold a workpiece while a central axis of a processed hole of the workpiece and the first rotational axis coincide with each other; and a holder drive unit to, by exerting a driving force on a portion of the workpiece holder corresponding to a point on an extension line of the first rotational axis in a direction along the first rotational axis, cause the workpiece holder to move in a second direction that is an opposite direction to the first direction.

2. The honing device according to claim 1, further comprising: a controller to control the axial direction driver in such a way that the main shaft vibrates in a direction along the first rotational axis in a periodic manner and also control the holder drive unit in such a way that the workpiece holder vibrates in a direction along the first rotational axis in a periodic manner with a same period as a period of the main shaft and in a vibration waveform with a phase difference from a vibration waveform of the main shaft.

3. The honing device according to claim 2, wherein the controller controls the holder drive unit to cause the workpiece holder to vibrate in a vibration waveform with a phase difference of x radians from a vibration waveform of the main shaft.

4. The honing device according to claim 2, further comprising: an input device through which a user inputs amplitude ratio information indicating an amplitude ratio of amplitude of a vibration waveform of the main shaft to amplitude of a vibration waveform of the workpiece holder, wherein the controller controls the axial direction driver and the holder drive unit in such a way that the main shaft and the workpiece holder vibrate at an amplitude ratio indicated by the amplitude ratio information.

5. The honing device according to claim 1, wherein the holder drive unit includes: a rack gear having a long length and arranged in such a way that a longitudinal direction of the rack gear is along the first rotational axis; and a pinion gear to rotate about a second rotational axis that is orthogonal to the first rotational axis and mesh with the rack gear on an extension line of the first rotational axis.

6. The honing device according to claim 1, wherein the workpiece holder includes: a workpiece rotation restrictor to restrict the workpiece from relatively rotating about a central axis of the processed hole with respect to the workpiece holder; a workpiece axial direction movement restrictor to restrict the workpiece from relatively moving in a central axis direction of the processed hole with respect to the workpiece holder; and a workpiece support mechanism to support the workpiece in a movable manner in a direction orthogonal to a direction along the first rotational axis in such a way that a central axis of the processed hole coincides with the first rotational axis.

7. The honing device according to claim 1, further comprising: a machine body including a head to collectively hold the honing tool, the main shaft, the rotation driver, and the axial direction driver and a supporting column having a long length, arranged in an attitude in which a longitudinal direction of the supporting column is along the vertical direction, and configured to support the head at one end on a vertically upper side, wherein the holder drive unit is fixed to the other end on a vertically lower side of the supporting column.

8. The honing device according to claim 3, further comprising: an input device through which a user inputs amplitude ratio information indicating an amplitude ratio of amplitude of a vibration waveform of the main shaft to amplitude of a vibration waveform of the workpiece holder, wherein the controller controls the axial direction driver and the holder drive unit in such a way that the main shaft and the workpiece holder vibrate at an amplitude ratio indicated by the amplitude ratio information.

9. The honing device according to claim 2, wherein the holder drive unit includes: a rack gear having a long length and arranged in such a way that a longitudinal direction of the rack gear is along the first rotational axis; and a pinion gear to rotate about a second rotational axis that is orthogonal to the first rotational axis and mesh with the rack gear on an extension line of the first rotational axis.

10. The honing device according to claim 3, wherein the holder drive unit includes: a rack gear having a long length and arranged in such a way that a longitudinal direction of the rack gear is along the first rotational axis; and a pinion gear to rotate about a second rotational axis that is orthogonal to the first rotational axis and mesh with the rack gear on an extension line of the first rotational axis.

11. The honing device according to claim 2, wherein the workpiece holder includes: a workpiece rotation restrictor to restrict the workpiece from relatively rotating about a central axis of the processed hole with respect to the workpiece holder; a workpiece axial direction movement restrictor to restrict the workpiece from relatively moving in a central axis direction of the processed hole with respect to the workpiece holder; and a workpiece support mechanism to support the workpiece in a movable manner in a direction orthogonal to a direction along the first rotational axis in such a way that a central axis of the processed hole coincides with the first rotational axis.

12. The honing device according to claim 3, wherein the workpiece holder includes: a workpiece rotation restrictor to restrict the workpiece from relatively rotating about a central axis of the processed hole with respect to the workpiece holder; a workpiece axial direction movement restrictor to restrict the workpiece from relatively moving in a central axis direction of the processed hole with respect to the workpiece holder; and a workpiece support mechanism to support the workpiece in a movable manner in a direction orthogonal to a direction along the first rotational axis in such a way that a central axis of the processed hole coincides with the first rotational axis.

13. The honing device according to claim 2, further comprising: a machine body including a head to collectively hold the honing tool, the main shaft, the rotation driver, and the axial direction driver and a supporting column having a long length, arranged in an attitude in which a longitudinal direction of the supporting column is along the vertical direction, and configured to support the head at one end on a vertically upper side, wherein the holder drive unit is fixed to the other end on a vertically lower side of the supporting column.

14. The honing device according to claim 3, further comprising: a machine body including a head to collectively hold the honing tool, the main shaft, the rotation driver, and the axial direction driver and a supporting column having a long length, arranged in an attitude in which a longitudinal direction of the supporting column is along the vertical direction, and configured to support the head at one end on a vertically upper side, wherein the holder drive unit is fixed to the other end on a vertically lower side of the supporting column.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIG. 1 is a perspective view of a honing device according to an embodiment of the present disclosure;

[0015] FIG. 2 is a side view of the honing device according to the embodiment;

[0016] FIG. 3 is a side view of a portion of the honing device according to the embodiment;

[0017] FIG. 4 is a cross-sectional arrow view of a portion of the honing device according to the embodiment taken along the line A-A in FIG. 3;

[0018] FIG. 5A is a cross-sectional view of a workpiece holder according to the embodiment;

[0019] FIG. 5B is a cross-sectional arrow view of the workpiece holder according to the embodiment taken along the line B-B in FIG. 5A;

[0020] FIG. 6A is a cross-sectional view illustrating, with respect to a holder drive unit according to the embodiment, a state in which a holder support is arranged at a lower limit position;

[0021] FIG. 6B is a cross-sectional view illustrating, with respect to the holder drive unit according to the embodiment, a state in which the holder support is arranged at an upper limit position;

[0022] FIG. 7A is a cross-sectional view illustrating a state in which a head and a workpiece holder are arranged at an upper limit position at the time of processing and a lower limit position at the time of processing, respectively, in the honing device according to the embodiment;

[0023] FIG. 7B is a diagram illustrating a state in which the head and the workpiece holder are arranged at a lower limit position at the time of processing and an upper limit position at the time of processing, respectively, in the honing device according to the embodiment;

[0024] FIG. 8A is a diagram illustrating vibration waveforms of the head and the workpiece holder of the honing device according to the embodiment;

[0025] FIG. 8B is a diagram illustrating vibration waveforms of the head and the workpiece holder in the case where amplitude of the workpiece holder of the honing device according to the embodiment is reduced;

[0026] FIG. 9 is a side view of a portion of a honing device according to a comparative example;

[0027] FIG. 10 is a perspective view of a honing device according to a variation; and

[0028] FIG. 11 is a side view of the honing device according to the variation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] A honing device according to an embodiment of the present disclosure is described below with reference to the drawings. The honing device according to the present embodiment includes a honing tool at a tip portion of which grindstones are disposed, a main shaft having a long length and to which the honing tool is fixed while the tip portion of the honing tool extends from one end side in the longitudinal direction of the main shaft, a rotation driver to cause the main shaft to rotate about a rotational axis along the longitudinal direction of the main shaft, and an axial direction driver to cause the main shaft to move in a first direction along the rotational axis. The honing device also includes a workpiece holder to hold a workpiece while a central axis of a processed hole of the workpiece and the rotational axis of the main shaft coincide with each other and a holder drive unit to, by exerting a driving force on a portion of the workpiece holder corresponding to a point on an extension line of the rotational axis in a direction along the rotational axis, cause the workpiece holder to move in a second direction that is the opposite direction to the first direction.

[0030] As illustrated in FIG. 1, the honing device according to the present embodiment is a device that processes an inner wall of a processed hole of a workpiece and includes a honing tool 1, a rotating main shaft 2, a workpiece holder 3, a holder drive unit 6 to support the workpiece holder 3 and drive the workpiece holder 3 in such a manner that the workpiece holder 3 vibrates in the Z-axis direction, and a machine body 9. Hereinafter, in the description of the present disclosure, the description is made under the assumption that a vertical up-down direction is referred to as a Z-direction or a Z-axis direction and directions that are orthogonal to the vertical direction and are orthogonal to each other are respectively referred to as a X-direction or an X-axis direction and a Y-direction or a Y-axis direction. As illustrated in FIG. 2, the honing device also includes a rotation driver 5, an axial direction driver 4, an expansion driver 8, and a controller 10 to control operation of the holder drive unit 6, the rotation driver 5, the axial direction driver 4, and the expansion driver 8. Note that in FIG. 2, a workpiece W is arranged in an attitude in which a central axis J2 of a processed hole Wh of the workpiece W and a central axis J1 of the rotating main shaft 2 coincide with each other. The machine body 9 includes a base 92 to support the workpiece holder 3 and the holder drive unit 6, a head 93 to collectively hold the honing tool 1, the rotating main shaft 2, the rotation driver 5, the axial direction driver 4, and the expansion driver 8, and a supporting column 91 erected on the base 92 and configured to support the head 93. The supporting column 91 has a long length, is arranged in an attitude in which the longitudinal direction of the supporting column 91 is along the vertical direction, that is, the Z-axis direction, and supports the head 93 at an end on the vertically upper side of the supporting column 91.

[0031] The honing tool 1 is formed in a long cylindrical shape and includes a tool main body 11 replaceably attached to the rotating main shaft 2 in such a manner as to extend in the Z-direction from a lower end 2a of the rotating main shaft 2 and a plurality of grindstones 12 disposed at an end on the Z-direction side of the tool main body 11 in an expandable and contractible manner in radial directions. In addition, the honing tool 1 includes a wedge rod (not illustrated) to, by relatively moving in the vertical direction with respect to the tool main body 11, cause the grindstones 12 to move in an expanding manner, the wedge rod including a wedge portion (not illustrated) disposed at an end on the Z-direction side of the wedge rod and being arranged while the wedge portion is in contact with inclined surfaces on the opposite sides to the grindstone 12 sides of grindstone bases (not illustrated) to which the grindstones 12 are fixed on the inner side of the tool main body 11, and a biasing member to bias the grindstones 12 in directions in which the grindstones 12 contract. The wedge rod is coupled to an expansion rod 87, which is described later, that is arranged on the +Z-direction side of the wedge rod on the inside of the rotating main shaft 2. In addition, the grindstones 12 are constantly biased in directions in which the grindstones 12 contract by the aforementioned biasing member. This configuration causes the grindstone bases and the grindstones 12 fixed to the grindstone bases to, in association with movement of the wedge rod in the Z-direction, be pressed by the wedge portion and move in directions in which the grindstones 12 expand. In contrast, when the wedge rod moves in the +Z-direction, the grindstone bases and the grindstones 12 move in directions in which the grindstones 12 contract by a biasing force of the biasing member. Note that as the biasing member, a ring spring, a ring-shaped rubber, or the like can be employed.

[0032] The rotating main shaft 2 has a spline shaft portion 2b, the spline shaft portion 2b being disposed on the +Z-direction side of the rotating main shaft 2, supported by the head 93 of the machine body 9 via a spline bearing 55 and is movable in the Z-axis direction with respect to the spline bearing 55 and rotatable about the central axis J1 along the longitudinal direction of the rotating main shaft 2. In this configuration, the rotational axis of the rotating main shaft 2, that is, a first rotational axis, coincides with the central axis J1.

[0033] The rotation driver 5 includes a motor 51, pulleys 52 and 54, and a belt 53 and causes the rotating main shaft 2 to rotate about the central axis J1 of the rotating main shaft 2, that is, the first rotational axis. To the pulley 54, the spline shaft portion 2b of the rotating main shaft 2 is spline-fitted. The pulley 54 is connected to the pulley 52 that is fixed to a motor shaft 51a of the motor 51 via the belt 53. The motor 51 is a servo motor in which a position detection sensor, such as a rotary encoder, and a torque sensor are incorporated, and the amount of rotation of the motor 51 is detected by the position detection sensor. When the pulley 52 is rotated by the motor 51, the rotating main shaft 2 the spline shaft portion 2b of which is spline-fitted to the pulley 54 and the honing tool 1 that is fixed to the rotating main shaft 2 rotate.

[0034] The axial direction driver 4 includes a sliding main body 42, a guide rail 43 to guide the sliding main body 42, a feed screw mechanism 41 to drive the sliding main body 42, a coupling 45, and a motor 44 and causes the rotating main shaft 2 to move in a direction along the central axis J1 of the rotating main shaft 2, that is, the first rotational axis. The sliding main body 42 supports the rotating main shaft 2 in a rotatable manner via bearings (not illustrated). The guide rail 43 extends in a linear shape along the Z-axis direction and is configured such that the sliding main body 42 is freely slidable on the guide rail 43 in the up-down direction. The feed screw mechanism 41 includes a feed screw nut 41a to which the sliding main body 42 is fixed and a feed screw 41b arranged along the vertical direction and axially supported by the machine body 9 in a rotatable manner and on which the feed screw nut 41a is screwed. The feed screw 41b has an end on the +Z-direction side connected to a motor shaft 44a of the motor 44 via the coupling 45. The motor 44 is a servo motor in which a position detection sensor, such as a rotary encoder, is incorporated, and the amount of rotation and a phase of the motor 44 is detected by the position detection sensor. When the feed screw 41b is rotated by the motor 44, the feed screw nut 41a and the sliding main body 42 to which the feed screw nut 41a is fixed move along the Z-axis direction and the rotating main shaft 2 and the honing tool 1 ascend or descend.

[0035] The expansion driver 8 causes the grindstones 12 to move in an expanding manner via the expansion rod 87 and the wedge rod fixed to the expansion rod 87. The expansion driver 8 includes the expansion rod 87 to which the wedge rod is fixed, a rod drive mechanism 85, a spline shaft 86a, a gear mechanism 82, and a motor 81. The expansion rod is movable along the Z-axis direction, and at an end on the Z-direction side of the expansion rod, the wedge rod is connected. The rod drive mechanism 85 is a mechanism for causing the expansion rod 87 to move in the vertical direction and includes a driven body 85a coupled to the expansion rod 87 and a feed screw 85b for causing the driven body 85a to move along the Z-axis direction. The feed screw 85b is axially supported by the sliding main body 42 in an attitude of being parallel with the rotating main shaft 2. To the driven body 85a, the expansion rod 87 is fixed, and the driven body 85a is relatively movable in the Z-axis direction with respect to the rotating main shaft 2 in conjunction with the expansion rod 87. The driven body 85a includes a feed screw nut (not illustrated) screwed onto the feed screw 85b and, when the feed screw 85b is rotated about the central axis of the feed screw 85b, moves in the Z-axis direction in association with the rotation.

[0036] The spline shaft 86a has an end on the Z-direction side connected to an end on the +Z-direction side of the feed screw 85b via a coupling 86c. In addition, an upper end portion of the spline shaft 86a is spline-fitted to a gear shaft 82a via a connection member 86b, and the spline shaft 86a is movable in the Z-axis direction with respect to the gear shaft 82a. In addition, the gear shaft 82a meshes with a gear 82b that is fixed to a motor shaft 81a of the motor 81. The motor 81 is a servo motor in which a position detection sensor, such as a rotary encoder, and a torque sensor are incorporated, and the amount of rotation of the motor 81 is detected by the position detection sensor. When the motor 81 causes the spline shaft 86a to rotate, the feed screw 85b connected to the spline shaft 86a rotates and the driven body 85a including the feed screw nut screwed onto the feed screw 85b relatively moves in the Z-axis direction with respect to the rotating main shaft 2. In this configuration, when the driven body 85a moves in the Z-direction, the expansion rod 87 and the wedge rod coupled to the the expansion rod 87 moves in the Z-direction and the grindstones 12 move in an expanding manner. In contrast, when the driven body 85a moves in the +Z-direction, the expansion rod 87 and the wedge rod coupled to the the expansion rod 87 moves in the +Z-direction and, in association with the movement, the aforementioned biasing member causes the grindstones 12 to move in a contracting manner.

[0037] The workpiece holder 3 includes, as illustrated in FIGS. 3 and 4, a holder main body 34, a base portion 31 on which the workpiece W clamped by the holder main body 34 is placed in conjunction with the holder main body 34, and a pressing member 32 formed in a plate shape, having a window portion 32a formed, the window portion 32a penetrating the pressing member 32 in the thickness direction, and arranged while being in contact with the +Z-direction side of the holder main body 34 placed on the base portion 31. The workpiece holder 3 also includes a plurality of supporting columns 33 each formed in a columnar shape and erected on a peripheral portion of the base portion 31 and to a tip portion of each of which a peripheral portion of the pressing member 32 is fixed. The workpiece holder 3 holds the workpiece W in an attitude in which the central axis J2 of the processed hole Wh of the workpiece W and the central axis J1 of the rotating main shaft 2 coincide with each other.

[0038] The holder main body 34 includes, as illustrated in FIGS. 5A and 5B, a holding cylinder 341 formed in a cylindrical shape and configured to hold the workpiece W while the workpiece W is fitted into the inside of the holding cylinder 341, a holding ring 342 formed in a ring shape and fitted onto a vicinity of an end on the +Z-direction side of the holding cylinder 341, and a base member 343 to collectively support the holding cylinder 341 and the holding ring 342 in a freely slidable manner in the Y-axis direction. The base member 343 is fixed to the base portion 31. In addition, the holder main body 34 includes two pins 3441 and two pins 3442. Each of the two pins 3441 is inserted into one of two through-holes 341a that are bored at two locations opposed to each other with the central axis of the holding cylinder 341 interposed between the two locations in the X-axis direction in a vicinity of an end on the +Z-direction side of the holding cylinder 341. In the holding cylinder 341, screw holes 341b each of which communicates with one of the through-holes 341a from the end on the +Z-direction side of the holding cylinder 341 and into each of which a set screw 346 for preventing one of the pins 3441 from falling off from the through-hole 341a while a tip portion of the set screw 346 is in contact with the pin 3441 is screwed are bored. The pins 3441 are fixed to the inside of the through-holes 341a by the set screws 346. In addition, a tip portion of each of the pins 3441 is insert into one of through-holes 342a penetrating a sidewall of the holding ring 342, and the holding cylinder 341 is, guided by the pins 3441 inserted into the through-holes 342a, freely slidable in the X-axis direction with respect to the holding ring 342.

[0039] In addition, each of the two pins 3442 is inserted into one of two through-holes

[0040] 342b that are bored at two locations opposed to each other with the center of the holding ring 342 interposed between the two locations in the Y-axis direction in a peripheral wall of the holding ring 342. In the holding ring 342, screw holes (not illustrated) each of which communicates with one of the through-holes 342b from an end on the +Z-direction side of the holding ring 342 and into each of which a set screw (not illustrated) for preventing one of the pins 3442 from falling off from the through-hole 342b while a tip portion of the set screw is in contact with the pin 3442 is screwed are also bored. The pins 3442 are fixed to the inside of the through-holes 342b by the set screws.

[0041] Further, the holder main body 34 includes a workpiece rotation restrictor 345 formed in an annular shape, including a protruding line portion 345a provided in a protruding manner on the +Z-direction side, and configured to restrict the workpiece W from rotating about the central axis J1 of the rotating main shaft 2 while the protruding line portion 345a is fitted into a recessed portion Wtr that is formed at an end on the Z-direction side of the workpiece W. The workpiece rotation restrictor 345 is placed on the +Z-direction side of the base portion 31 and is freely slidable in an XY-direction with respect to the base portion 31. In addition, the holder main body 34 includes a workpiece axial direction movement restrictor 347 formed in an annular shape, having a rib 347a provided in a protruding manner, the rib 347a having a portion thereof fitted into the inside of the window portion 32a of the pressing member 32, and configured to have the Z-direction side of the workpiece axial direction movement restrictor 347 coming into contact with the end on the +Z-direction side of the workpiece W, clamp the workpiece W in conjunction with the base member 343, and restrict the workpiece W from relatively moving in a direction along the central axis J2 of the processed hole Wh with respect to the workpiece holder 3.

[0042] The base member 343 includes a main body portion 343a formed in a flat shape, arranged on the Z-direction side of the workpiece W, and coming into contact with the end on the Z-direction side of the workpiece W and supporting column portions 343b each extending in the +Z-direction from the main body portion 343a and having, on a tip portion of the supporting column portion 343b, a through-hole 343c formed into which a tip portion of one of the pins 3442 fixed to the holding ring 342 is inserted. The holding ring 342 is, guided by the pins 3442 inserted into the through-holes 343c, freely slidable in the Y-axis direction with respect to the base member 343. In this configuration, the holding cylinder 341, the holding ring 342, the pins 3441 and 3442, and the base member 343 constitute a workpiece support mechanism that supports the workpiece W in a movable manner in at least one of the X-axis direction and the Y-axis direction in such a way that the central axis J2 of the processed hole Wh of the workpiece W coincides with the rotational axis, that is, the central axis J1, of the rotating main shaft 2. Note that the sliding mechanism is not limited to a mechanism for supporting the workpiece W in a freely slidable manner in an in-plane direction orthogonal to the central axis J1. For example, the sliding mechanism may be a workpiece support mechanism that supports the workpiece W while the attitude of the workpiece W can be changed in not only an in-plane direction orthogonal to the central axis J1 but also a direction in which the central axis J2 of the processed hole Wh is inclined with respect to the central axis J1.

[0043] Returning to FIGS. 3 and 4, the holder drive unit 6, by exerting a driving force on a portion of the workpiece holder 3 corresponding to a point on an extension line of the central axis J1 in a direction along the central axis J1, causes the workpiece holder 3 to move in the opposite direction to a direction of movement of the rotating main shaft 2. The holder drive unit 6 includes a rack gear 62 having a long length and arranged in such a manner that the longitudinal direction of the rack gear 62 is along the central axis J1 direction, that is, the Z-axis and a pinion gear 63 to rotate about a central axis J3, that is, a second rotational axis, of a shaft 642, which is described later, the central axis J3 being orthogonal to the Z-axis, and mesh with the rack gear 62 on the extension line of the central axis J1 when viewed from the +X-direction. In addition, the holder drive unit 6 includes a driver main body 69, a holder support 61 to support the workpiece holder 3, a gear driver 64 to rotation-drive the pinion gear 63, and rails 65 to support the holder support 61 in a freely movable manner along the Z-axis direction.

[0044] The holder support 61 includes a main piece 611 formed in a plate shape and arranged in an attitude in which a thickness direction of the main piece 611 is orthogonal to the Z-axis direction and a support piece 612 formed in a plate shape, arranged in such a manner that a thickness direction of the support piece 612 is along the Z-axis direction, and configured to support the workpiece holder 3 on the +Z-direction side of the support piece 612. In the main piece 611, a long hole 611a that extends in the Z-axis direction and penetrates the main piece 611 in the thickness direction is formed. In addition, the holder support 61 includes sliding bodies (illustrated) fixed to the Y-direction side of the main piece 611 and freely movable in the Z-axis direction while being suspended on the rails 65.

[0045] The rack gear 62 includes a plurality of teeth 62a arranged in a line along the longitudinal direction and is fixed to the main piece 611 in such a way that the plurality of teeth 62a projects toward the inside of the long hole 611a when viewed from the +Y-direction side. The pinion gear 63 includes a wheel 631 formed in a circle in plan view and a plurality of rollers 632 arranged on a peripheral portion of the wheel 631 along the circumferential direction of the wheel 631 at equal intervals. Each of the plurality of rollers 632 has a central axis of the roller 632 aligned parallel with a direction along the central axis J3 of the shaft 642, that is, the second rotational axis of the pinion gear 63 and is supported by the wheel 631 in a freely rotatable manner about the central axis of the roller 632. The pinion gear 63 is inserted into the long hole 611a of the holder support 61 while the plurality of rollers 632 of the pinion gear 63 mesh with the teeth 62a of the rack gear 62.

[0046] The gear driver 64 includes a motor 641, a reduction gear 643 including an input shaft (not illustrated) coupled to an output shaft (not illustrated) of the motor 641, and the shaft 642 coupled to an output shaft (not illustrated) of the reduction gear 643 and to which the wheel 631 of the pinion gear 63 is fixed. The motor 641 is a servo motor in which a position detection sensor, such as a rotary encoder, is incorporated, and the amount of rotation and a phase of the motor 641 is detected by the position detection sensor. The reduction gear 643 is, for example, a ball reduction gear.

[0047] In the holder drive unit 6, as illustrated in FIG. 6A, when the gear driver 64 causes the pinion gear 63 fixed to the shaft 642 to rotate counterclockwise when viewed from the +Y-direction as illustrated by an arrow AR11, the holder support 61 to which the rack gear 62 meshing with the pinion gear 63 is fixed moves to the +Z-direction side as illustrated by an arrow AR12. Then, as illustrated in FIG. 6B, the holder support 61 is arranged on the +Z-direction side. In contrast, when while the holder support 61 is arranged at a position illustrated in FIG. 6B, the gear driver 64 causes the pinion gear 63 fixed to the shaft 642 to rotate clockwise when viewed from the +Y-direction as illustrated by an arrow AR21, the holder support 61 to which the rack gear 62 meshing with the pinion gear 63 is fixed moves to the Z-direction side as illustrated by an arrow AR22. Then, as illustrated in FIG. 6A, the holder support 61 is arranged on the Z-direction side again. In this way, the gear driver 64, by alternately repeating causing the pinion gear 63 to rotate counterclockwise and to rotate clockwise when viewed from the +Y-direction, causes the holder support 61 and the workpiece holder 3 supported by the holder support 61 to vibrate along the Z-axis direction.

[0048] Returning to FIG. 2, the controller 10 is, for example, a programable logic controller (PLC) and includes a central processing unit (CPU) unit and an input/output control unit. The controller 10, by outputting control signals to the gear driver 64 of the holder drive unit 6, the rotation driver 5, the axial direction driver 4, and the expansion driver 8 via the input/output control unit, controls operation of the foregoing drivers. The controller 10 controls the axial direction driver 4 in such a way that the rotating main shaft 2 vibrates along the Z-axis direction in a periodic manner, as well as controlling the gear driver 64 of the holder drive unit 6 in such a way that the workpiece holder 3 vibrates along the Z-axis direction in a periodic manner with the same period as that of the rotating main shaft 2 and in a vibration waveform with a phase difference from a vibration waveform of the rotating main shaft 2. The controller 10, by controlling, for example, the axial direction driver 4, causes the rotating main shaft 2 to move in the first direction along the Z-axis direction and at the same time, by controlling the gear driver 64, causes the workpiece holder 3 to move in the second direction that is the opposite direction to the aforementioned first direction.

[0049] While as illustrated in, for example, FIG. 7A, an end on the Z-direction side of the rotating main shaft 2 is arranged at a position Pos11 and the end on the +Z-direction side of the workpiece W is arranged at a position Pos12, the controller 10, by controlling the axial direction driver 4, causes the rotating main shaft 2 to move in the Z-direction as illustrated by an arrow AR13 and at the same time, by controlling the gear driver 64, causes the workpiece holder 3 to move in the +Z-direction as illustrated by an arrow AR12. Through this processing, as illustrated in FIG. 7B, the end on the Z-direction side of the rotating main shaft 2 is arranged at a position Pos21 and the end on the +Z-direction side of the workpiece W held by the workpiece holder 3 is arranged at a position Pos22, and the rotating main shaft 2 and the workpiece holder 3 are brought into a state of being close to each other. While the rotating main shaft 2 and the workpiece holder 3 are in a state illustrated in FIG. 7B, the controller 10 causes the rotating main shaft 2 to move in the +Z-direction as illustrated by an arrow AR23 and at the same time, by controlling the gear driver 64, causes the workpiece holder 3 to move in the Z-direction as illustrated by an arrow AR22. Through this processing, as illustrated in FIG. 7A, the end on the Z-direction side of the rotating main shaft 2 is arranged at the position Pos11 and the end on the +Z-direction side of the workpiece W held by the workpiece holder 3 is arranged at the position Pos12 again, and the rotating main shaft 2 and the workpiece holder 3 are brought into a state of being separated from each other. The controller 10, by controlling the axial direction driver 4 and the gear driver 64 and alternately repeating movement of the rotating main shaft 2 in the Z-direction and movement of the workpiece holder 3 in the +Z-direction and movement of the rotating main shaft 2 in the +Z-direction and movement of the workpiece holder 3 in the Z-direction, causes the rotating main shaft 2 and the workpiece holder 3 to vibrate along the Z-axis direction.

[0050] In addition, the controller 10 controls the axial direction driver 4 and the gear driver 64 in such a way that a vibration waveform of the end on the Z-direction side of the rotating main shaft 2 and a vibration waveform of the end on the +Z-direction side of the workpiece W become sine wave waveforms with amplitudes L1 and L21, respectively, as illustrated in, for example, FIG. 8A. In this configuration, the controller 10 controls the gear driver 64 of the holder drive unit 6 to cause the workpiece holder 3 to vibrate with a vibration waveform having a phase difference of x radians from the vibration waveform of the rotating main shaft 2. In addition, the controller 10 controls the axial direction driver 4 and the gear driver 64 in such a way that, for example, movement speed of the rotating main shaft 2 in the Z-axis direction becomes 25 m/min and movement speed of the workpiece W becomes 25 m/min and, as a result, relative speed of the workpiece W with respect to the rotating main shaft 2 becomes 50 m/min.

[0051] Further, the controller 10 controls the gear driver 64 of the holder drive unit 6 to cause the workpiece holder 3 to vibrate in such a manner that the larger weight of the workpiece W is, the smaller vibration amplitude becomes. The controller 10 controls the gear driver 64 to, when the weight of the workpiece W increases, change the amplitude of a vibration waveform of the end on the +Z-direction side of the workpiece W from the amplitude L21 to an amplitude L22 that is smaller than the amplitude L21 in association with the increase in the weight, as illustrated in, for example, FIG. 8B. In this case, the controller 10 controls the axial direction driver 4 and the gear driver 64 in such a way that the vibration period of the rotating main shaft 2 and the vibration period of the workpiece W become equal to each other and, for example, the movement speed of the rotating main shaft 2 in the Z-axis direction becomes 25 m/min and the movement speed of the workpiece W becomes 12.5 m/min and, as a result, relative speed of the workpiece W with respect to the rotating main shaft 2 becomes 37.5 m/min.

[0052] Features of the honing device according to the present embodiment is described below in comparison with a honing device according to a comparative example. The honing device according to the comparative example includes a holder drive unit 9006 to drive a workpiece holder 3 in the Z-axis direction by a linear motor 9064 as illustrated in FIG. 9. Note that, in FIG. 9, the same constituent elements as those in the embodiment are provided with the same reference numerals as those in FIGS. 2 and 4. The holder drive unit 9006 includes a holder support 9061 to support the workpiece holder 3, a rail 9661 having a long length and arranged in an attitude in which the longitudinal direction of the rail 9661 is along the Z-axis direction, and sliding bodies 9662 to which the holder support 9061 is fixed and that are freely movable in the Z-axis direction while being suspended on the rail 9661. In this configuration, the holder support 9061 includes a main portion 9611 and a support piece 612 fixed to the +Z-direction side of the main portion 9611. In addition, the linear motor 9064 includes a stator 9641 having a long length and arranged along the rail 9661 and a mover 9642 to move in the Z-axis direction by a driving force in a central axis J94 direction that is along the longitudinal direction of the stator 9641.

[0053] In the holder drive unit 9006 according to the comparative example, when the workpiece holder 3 is caused to move in the +Z-direction in, for example, honing of a workpiece W, a driving force is exerted on a portion of the mover 9642 corresponding to the stator 9641 in a direction illustrated by an arrow AR91. In addition, when a honing tool 1 is caused to move in the Z-direction while the honing tool 1 is inserted into a processed hole Wh, in association with grindstones 12 of the honing tool 1 sliding in the Z-direction on an inner wall of the processed hole Wh of the workpiece W held by the workpiece holder 3, a resistance force caused by friction between the grindstones 12 and the inner wall of the processed hole Wh is exerted on the workpiece W in a direction illustrated by an arrow AR92 along a central axis J2 of the processed hole Wh. As described above, in the honing device according to the comparative example, a position on the mover 9642 at which a driving force is exerted and a position at which a resistance force applied to the workpiece W is exerted are shifted from each other in a direction orthogonal to the central axis J2 of the processed hole Wh. Thus, a force in a direction causing the holder support 9061 to be elastically deformed is exerted on the holder support 9061, as illustrated by an arrow AR93 due to inertial force associated with self-weight of the workpiece holder 3 and a resistance force applied to the workpiece W. The holder support 9061 being elastically deformed causes the central axis J2 of the processed hole Wh of the workpiece W that the workpiece holder 3 supported by the holder support 9061 holds to be inclined with respect to the Z-axis direction, as a result of which there is a risk that processing accuracy of the processed hole Wh deteriorates.

[0054] In contrast, in the honing device according to the present embodiment, a portion of the holder drive unit 6 in which the rack gear 62 and the pinion gear 63 mesh with each other is located in a vicinity of the central axis J2 of the processed hole Wh of the workpiece W held by the workpiece holder 3, as illustrated in FIGS. 3 and 4. Thus, the holder drive unit 6 is capable of exerting a driving force on the central axis J2 of the workpiece holder 3, that is, a portion of the workpiece holder 3 corresponding to a point on an extension line of the central axis J1 of the rotating main shaft 2, in a direction along the central axes J1 and J2. In other words, in the honing, it is possible to cause a driving force exerted on the workpiece holder 3, inertial force caused by the self-weight of the workpiece holder 3, and a resistance force applied to the workpiece W to act substantially on the central axes J1 and J2. Since because of this configuration, force in a direction causing the holder support 61 of the holder drive unit 6 to be elastically deformed is reduced, it is possible to prevent the central axis J2 of the workpiece W that the workpiece holder 3 holds from being inclined with respect to the Z-axis and the processing accuracy of the processed hole Wh can be increased accordingly.

[0055] As described in the foregoing, the axial direction driver 4 causes the rotating main shaft 2 to which the honing tool 1 is fixed to move in the Z-axis direction. In addition, the holder drive unit 6, by exerting a driving force on a portion of the workpiece holder 3 corresponding to a point on an extension line of the central axis J1 of the rotating main shaft 2 in the Z-axis direction, causes the workpiece holder 3 to move in the Z-axis direction. Because of this configuration, in the honing of the workpiece W, it is possible to, while increasing relative speed of the honing tool 1 with respect to the workpiece W, cause a position at which the holder drive unit 6 exerts a driving force on the workpiece holder 3 and a position at which a resistance force caused by frictional resistance between the processed hole Wh of the workpiece W held by the workpiece holder 3 and the grindstones 12 of the honing tool 1 is exerted to substantially coincide with each other in the Z-axis direction of the rotating main shaft 2. Since therefore, a force exerted in a direction in which the workpiece holder 3 is inclined is prevented from occurring, the central axis J2 of the processed hole Wh of the workpiece W can be prevented from being inclined with respect to the Z-axis direction and processing accuracy of the workpiece W can be improved.

[0056] In addition, the controller 10 according to the present embodiment controls the holder drive unit 6 to cause the workpiece holder 3 to vibrate in a vibration waveform with a phase difference of x radians from a vibration waveform of the rotating main shaft 2. Since because of this configuration, relative speed of the honing tool 1 with respect to the workpiece W in the honing of the workpiece W can be maximized, processing efficiency can be increased accordingly.

[0057] When a holder drive unit is to be achieved by making use of a linear motor or a feed screw and nut, since a stator of the linear motor or the feed screw has a long length, a space large enough to allow the entire holder drive unit to be arranged on the Z-direction side of a workpiece holder 3 is required to be provided. In particular, in the case where a linear motor is to be made use of, when a mover is to be driven at a high speed, the stator becomes larger in size accordingly. In contrast, the holder drive unit 6 according to the present embodiment includes the aforementioned rack gear 62 and the pinion gear 63 meshing with the rack gear 62 at a position on the extension line of the central axis J1 of the rotating main shaft 2. Since because of this configuration, the holder drive unit 6 is achieved by components, such as the rack gear 62 and the pinion gear 63, that are small compared with the stator of a linear motor or a feed screw, the entire holder drive unit 6 can be miniaturized accordingly.

[0058] Further, in the workpiece holder 3 according to the present embodiment, the workpiece support mechanism supports the workpiece W in a movable manner in at least one of the X-axis direction and the Y-axis direction in such a way that the central axis J2 of the processed hole Wh of the workpiece W coincides with the central axis J1 of the rotating main shaft 2. Since because of this configuration, it is possible to, when the workpiece holder 3 is caused to vibrate, prevent strain caused by the central axis J2 of the processed hole Wh of the workpiece W and the central axis J1 of the rotating main shaft 2 being shifted from each other from being applied to the workpiece W, a force in a direction causing the entire workpiece holder 3 to be inclined can be prevented from occurring.

[0059] The embodiment of the present disclosure was described above, but the present disclosure is not limited to the configuration of the aforementioned embodiment. For example, the controller 10 may be a controller that controls the gear driver 64 of the holder drive unit 6 to cause the workpiece holder 3 to vibrate in a vibration waveform with a phase difference of less than x radians from a vibration waveform of the rotating main shaft 2.

[0060] In the embodiment, the holder drive unit may be a holder drive unit that includes a swing mechanism (not illustrated) to support the entire workpiece holder 3 on the +Z-direction side of the support piece 612 of the holder support 61 in a freely swingable manner in a direction orthogonal to the Z-axis direction, that is, a direction along the XY-plane, and a swing reducing mechanism to reduce the swing of the workpiece holder 3. In this configuration, the swing reducing mechanism may be a mechanism that includes a slider (not illustrated) coming into contact with, for example, a lateral side of the workpiece holder 3 and being freely movable in a direction orthogonal to the Z-axis, a slider holder (not illustrated) to hold the slider in a freely movable manner, and a biasing device (not illustrated) to bias the slider that the slider holder holds in a direction in which the slider comes close to the workpiece holder 3.

[0061] According to the present configuration, it is possible to adjust the workpiece W in such a way that the central axis J2 of the processed hole Wh of the workpiece W coincides with the central axis J1 of the rotating main shaft 2 in an XY-plane orthogonal to the Z-axis direction.

[0062] In the embodiment, the honing device may be a honing device that includes an input device (not illustrated) through which a user inputs amplitude ratio information indicating an amplitude ratio of amplitude of a vibration waveform of the main shaft to amplitude of a vibration waveform of the workpiece holder. In this configuration, examples of the input device include a touch pad and a key input device. In this case, the controller 10 is only required to control the axial direction driver 4 and the holder drive unit 6 in such a way that the rotating main shaft 2 and the workpiece holder 3 vibrate at an amplitude ratio indicated by amplitude ratio information input through the input device.

[0063] According to the present configuration, when the user inputs, through the input device, amplitude ratio information in such a manner that the larger the weight of the workpiece W is, the smaller the vibration amplitude of the workpiece holder 3 becomes while the vibration amplitude of the rotating main shaft 2 is kept constant, in the case where the weight of the workpiece W is large, acceleration of the workpiece holder 3 when the workpiece holder 3 is caused to vibrate can be reduced according to the weight. Therefore, a load applied to the holder drive unit 6 when a workpiece W with a large weight is honed can be reduced.

[0064] In the embodiment, an example in which the holder drive unit 6 is fixed to the base 92 was described. However, the present disclosure is not limited to the example, and as illustrated in FIGS. 10 and 11, the honing device may be a honing device that includes a machine body 2009 in which a holder drive unit 6 is fixed to a supporting column 2091 having a long length, arranged in an attitude in which a longitudinal direction of the supporting column 2091 is along the vertical direction, and configured to support a head 93 at an end on the vertically upper side of the supporting column 2091. Note that, in FIGS. 10 and 11, the same constituent elements as those in the embodiment are provided with the same reference numerals as those in FIGS. 1 and 2. In this configuration, the holder drive unit 6 is fixed to the other end on the vertically lower side of the supporting column 2091. In this configuration, the holder drive unit 6 is arranged in an attitude in which a central axis J3 of a shaft 642 to which a pinion gear 63 of the holder drive unit 6 is fixed is along the X-axis direction.

[0065] Since according to the present configuration, the head 93 and the holder drive unit 6 can be collectively arranged in a vicinity of the supporting column 2091, the machine body 2009 can be miniaturized accordingly.

[0066] The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.

[0067] This application claims the benefit of Japanese Patent Application No. 2022-095448, filed on Jun. 14, 2022, the entire disclosure of which is incorporated by reference herein.

INDUSTRIAL APPLICABILITY

[0068] The present disclosure is suitable for a honing device that processes a gear, an injector component, or the like used for a transmission.

REFERENCE SIGNS LIST

[0069] 1 Honing tool [0070] 2 Rotating main shaft [0071] 2a Lower end [0072] 2b Spline shaft portion [0073] 3 Workpiece holder [0074] 4 Axial direction driver [0075] 5 Rotation driver [0076] 6 Holder drive unit [0077] 8 Expansion driver [0078] 9, 2009 Machine body [0079] 10 Controller [0080] 11 Tool main body [0081] 12 Grindstone [0082] 31 Base portion [0083] 32 Pressing member [0084] 32a Window portion [0085] 33, 2091 Supporting column [0086] 34 Holder main body [0087] 41 Feed screw mechanism [0088] 41a Feed screw nut [0089] 41b, 85b Feed screw [0090] 42 Sliding main body [0091] 43 Guide rail [0092] 45,86c Coupling [0093] 44, 51, 81, 641 Motor [0094] 44a, 51a Motor shaft [0095] 52, 54 Pulley [0096] 53 Belt [0097] 55 Spline bearing [0098] 61 Holder support [0099] 62 Rack gear [0100] 62a Tooth [0101] 63 Pinion gear [0102] 64 Gear driver [0103] 65 Rail [0104] 69 Driver main body [0105] 82 Gear mechanism [0106] 82a Gear shaft [0107] 82b Gear [0108] 85 Rod drive mechanism [0109] 85a Driven body [0110] 86a Spline shaft [0111] 86b Connection member [0112] 87 Expansion rod [0113] 91 Supporting column [0114] 92 Base [0115] 93 Head [0116] 341 Holding cylinder [0117] 341a, 342a, 342b, 343c Through-hole [0118] 341b Screw hole [0119] 342 Holding ring [0120] 343 Base member [0121] 343a Main body portion [0122] 343b Supporting column portion [0123] 345 Workpiece rotation restrictor [0124] 345a Protruding line portion [0125] 346 Set screw [0126] 347 Workpiece axial direction movement restrictor [0127] 347a Rib [0128] 611 Main piece [0129] 611a Long hole [0130] 612 Support piece [0131] 631 Wheel [0132] 632 Roller [0133] 642 Shaft [0134] 643 Reduction gear [0135] 3441, 3442 Pin [0136] J1, J2, J3 Central axis [0137] W Workpiece [0138] Wh Processed hole