Superfinishing stone changing method and superfinishing stone changing apparatus

Abstract

To provide a method for exchanging a grinding wheel in which functions are distributed and simplified and which stably operates.SOLUTION: The grinding wheel fixing device 12 energizes an inside clamp rod 29 to the side of the grinding wheel St and fixes the grinding wheel to a holding hole 31. The clamp rod is exposed on the opposite side of the energizing direction, and a locking part 41 is provided at the end. An oscillating device main body 2 is provided with an engaging part 54 reciprocating and engageable with the locking part. The fixed state of the grinding wheel is released by turning the grinding wheel fixing device to one side around the rocking shaft Sa, moving the engaging part forward, and moving the locking part to the opposite side of the energizing force. The extrusion rod 63 is inserted into the holding hole to evacuate the grinding wheel, the position adjusting surface is moved below the lower opening of the holding hole, and the magazine body 71 storing the grinding wheel is moved above the upper opening of the holding hole. The extrusion rod is inserted into the magazine main body and extruded into the holding hole until the grinding wheel abuts on the position adjusting surface and then retreated. The engaging part is moved backward to release the engagement with the locking part, the grinding wheel is fixed to the holding hole, and the grinding wheel fixing device is turned to the other side around the rocking shaft.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method and device for replacing a superfinishing grindstone in an apparatus (grindstone oscillating device) that superfinishes the inner and outer rings of a ball bearing and the groove surfaces of a ball screw. [Background technology]

[0002] Ball bearings are used as bearings for rotating equipment, and ball screws are used as mechanical elements that convert rotational motion into linear motion. They are used in combination with servo motors or stepping motors to transport objects, move moving parts in machine tools, and position them, and are also used to operate industrial robots, etc.

[0003] The inner and outer rings of a ball bearing, and the threaded shaft and nut of a ball screw, all have grooves formed on the curved surfaces that the balls roll in. The lower the roughness of the surfaces of these grooves (called "groove surfaces"), the smoother the rotation, the higher the positioning accuracy, the less operating noise there is, and the longer the service life.

[0004] Superfinishing is a known polishing method that can reduce the roughness of the groove surfaces of the inner and outer rings of ball bearings, the threaded shafts of ball screws, and nuts, and achieve a mirror finish. Superfinishing of these groove surfaces is performed by rotating a superfinishing grinding stone forward and backward at high speed, with the longitudinal direction of the groove (for example, the circumferential direction for the inner ring) as the oscillation axis.

[0005] However, because superfinishing wheels produce a mirror finish as they wear, the ground surface inevitably recedes, and the wheels must be replaced after a certain number of workpieces have been superfinished.The grooves on the inner rings of ball bearings, etc. that are the subject of superfinishing, are often small, and manually replacing small wheels that have become unusable due to wear takes time, which reduces processing efficiency.

[0006] To address this issue, an automatic grinding wheel changer has been proposed for superfinishing grooves in the outer rings of ball bearings, which automatically replaces a worn grinding wheel with one of multiple replacement grinding wheels stored upright in a row in a grinding wheel storage unit by operating a grinding wheel supply piston or the like (Patent Document 1).However, because the automatic grinding wheel changer proposed in Patent Document 1 oscillates together with the grinding wheel during superfinishing, the large inertial force during oscillation increases the burden on the power source for oscillation, and there are concerns that the durability of the device (superfinishing machine) may be reduced.

[0007] Therefore, a technique has been proposed in which an automatic grinding wheel changer is separated from the oscillating grinding wheel (grinding wheel head) to reduce the inertial force of the oscillating object when the grinding wheel is oscillated (Patent Document 2). [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 59-30638 [Patent Document 2] Japanese Patent Application Publication No. 59-196159 Summary of the Invention [Problem to be solved by the invention]

[0009] The automatic grinding wheel changer proposed in Patent Document 2 replaces one of the replacement grinding wheels stored in a row inside the grinding wheel magazine with a worn grinding wheel held in a grinding wheel holder by a grinding wheel pushing mechanism integrated into the grinding wheel magazine. The incorporation of multiple functions required for wheel replacement has made the system more complex, and there are concerns that the stability of the wheel replacement operation may deteriorate.

[0010] The present invention has been made in view of the above-mentioned problems, and has as its object to provide a method and device for changing a superfinishing grindstone in which the functions required for grindstone changing are distributed and simplified, and in which stability in the grindstone changing operation can be expected. [Means for solving the problem]

[0011] The method for replacing a superfinishing grindstone according to the present invention is for a grindstone oscillating device that performs superfinishing by oscillating a grindstone clamping device that fixes the grindstone using an oscillating motor. The grindstone is fixed to the grindstone clamping device of the grindstone oscillating device by using an urging member to urge a rod-shaped clamp rod housed in a push hole of the grindstone clamping device toward the grindstone holding hole that holds the grindstone.

[0012] The grindstone fixing device has an exposed clamp rod on the side opposite to the biasing direction of the biasing member, and a release locking part is provided near the exposed end. The main body that holds the swing motor has an engaging part that moves back and forth and can engage with the release locking part when moving forward.

[0013] To replace the grinding wheel, the grinding wheel fixing device is rotated forward or backward by the swing motor to bring the release locking part into engagement with the engagement part. Then, the engagement part is moved forward to engage with the release locking part, moving the clamp rod in the opposite direction to the biasing direction and releasing the grinding wheel from the grinding wheel holding hole.

[0014] Next, the push rod of the grinding wheel push-out device integrated with the main body is inserted through the opening of the grinding wheel holding hole to eject the held grinding wheel, and the push rod is retracted from the grinding wheel holding hole. The position adjustment surface of the grinding wheel position adjustment device integrated with the main body is moved near the opening in the grinding wheel holding hole on the opposite side to the opening through which the push rod was inserted, and the magazine main body integrated with the main body and containing multiple replacement grinding wheels is moved near the opening through which the push rod was inserted.

[0015] Next, the push rod is inserted into the magazine body, and one of the replacement grinding wheels is pushed into the grinding wheel holding hole until its grinding surface abuts the position adjustment surface, after which the push rod is retracted from the magazine body and the position adjustment surface is moved away from the opening of the grinding wheel holding hole.Then, the engaging portion is returned to release the engagement with the fixation release locking portion to fix a new grinding wheel in the grinding wheel holding hole, and the swing motor is used to rotate the grinding wheel fixing device in the other direction, thereby canceling the engageable state between the fixation release locking portion and the engaging portion.

[0016] Preferably, the cross section of the portion of the clamp bar exposed to the outside from the other end of the push hole is circular, and the locking release locking portion is ring-shaped like a thick washer. The engaging portion is formed by a locking groove into which the exposed portion of the clamp bar can be fitted, and a contact surface on its forward movement side that can engage with the locking release locking portion.

[0017] The superfinishing wheel replacement device of the present invention comprises a wheel fixing device which is oscillated by an oscillating motor and has a wheel holding hole at one end of its elongated longitudinal direction through which a superfinishing wheel can be passed and fixed; a main body which holds the oscillating motor; a wheel position adjustment device which is movable near the opening in the wheel holding hole on the grinding surface side of the wheel and has a position adjustment surface facing said opening; a clamp release device which has an engaging portion which can move back and forth; a magazine body which stores a plurality of new replacement wheels in parallel and has a push rod insertion port on the side opposite the grinding surface of the most (front) wheel and a wheel discharge port on the grinding surface side, both of which penetrate from the inside to the outside, and which is movable near the opening in the wheel holding hole on the side opposite the opening on the grinding surface side of the wheel; and a wheel extrusion device which has a push rod which enters the magazine body through the push rod insertion port and pushes the most end wheel in the magazine body outwards from within the magazine body.

[0018] The operations of the swing motor, the grinding wheel position adjusting device, the clamp releasing device, the magazine body, and the grinding wheel pushing device are controlled by a control device.

[0019] The grinding wheel fixing device has a push hole having one end that opens into the grinding wheel holding hole and extends longitudinally to have the other end open, a clamp rod that is movably housed within the push hole, extends exposed from the other end of the push hole, and has a release locking portion at its extended end, and a biasing member that biases the clamp rod toward the grinding wheel holding hole to fix the grinding wheel in the grinding wheel holding hole.

[0020] The clamp release device is configured so that when the engagement portion engages with the release latch portion and moves forward, it moves the clamp bar in the opposite direction to the biasing direction of the biasing member.

[0021] In the grinding wheel changer, the rocking motor rotates the grinding wheel clamping device in either the forward or reverse direction, thereby placing the release locking portion and the engaging portion in an engageable state. Subsequently, when the engaging portion is moved forward, the engaging portion engages with the release locking portion, thereby releasing the grinding wheel from the grinding wheel holding hole. Furthermore, when the engaging portion moves backward, the grinding wheel changer returns to an engageable state, and the grinding wheel in the grinding wheel holding hole is fixed to the grinding wheel clamping device, after which the position adjustment surface moves away from the opening of the grinding wheel holding hole. When the rocking motor rotates the grinding wheel clamping device in the other forward or reverse direction, the engageable state is released, allowing the next superfinishing.

[0022] The grinding wheel changing device is preferably such that the grinding wheel position adjusting device, the clamp releasing device, the magazine body, and the grinding wheel pushing device are integrated into the main body.

[0023] The grindstone changer has a base that supports a main body so that the main body can move back and forth in the direction of the rotation axis of the swing motor.

[0024] Preferably, the clamp release device and the grindstone position adjusting device are supported on the same frame, and the frame is fixed to the main body.

[0025] The grindstone fixing device is connected to the swing motor via an air cylinder that reciprocates the grindstone fixing device in the direction in which the grindstone holding hole penetrates.

[0026] When viewed from the direction in which the oscillating shaft of the oscillating motor extends, the direction in which the engaging portion of the clamp release device moves forward is the same as the direction in which it moves toward the vicinity of the opening on the opposite side of the grinding surface side of the grinding wheel holding hole in the magazine body, and the direction in which the push rod of the grinding wheel push-out device moves when it enters the magazine body is perpendicular to the direction in which the engaging portion moves forward.

[0027] Preferably, the cross-sectional shape of the portion of the clamp bar exposed to the outside from the other end of the push hole is circular. The locking release portion is ring-shaped like a thick washer. The engaging portion has a locking groove into which the exposed portion of the clamp bar can be fitted, and an abutment surface on its forward movement side that can engage with the locking release portion. [Effects of the Invention]

[0028] According to the present invention, by streamlining the multiple functions required for changing a grinding wheel and simplifying the structure of each, it is possible to provide a method and device for changing a superfinishing grinding wheel that can be expected to provide a highly stable grinding wheel changing operation. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 is a perspective view of the grindstone oscillating device. [Figure 2] FIG. 2 is a partial cross-sectional plan view of the grindstone oscillating device. [Figure 3] FIG. 3 is a partial cross-sectional front view of the grindstone oscillating device. [Figure 4] FIG. 4 is a partial front cross-sectional view of the main part of the grindstone oscillating device. [Figure 5] FIG. 5 is a perspective view of the stone head. [Figure 6] FIG. 6 is a plan view of the stone head. [Figure 7] FIG. 7 is a front view of the stone head. [Figure 8] FIG. 8 is a cross-sectional view of the grindstone clamping device. [Figure 9] FIG. 9 is a perspective view of the grindstone clamping release device. [Figure 10] FIG. 10 is a front view of the grindstone clamping release device. [Figure 11] FIG. 11 is a plan view of the grindstone clamping release device. [Figure 12] FIG. 12 is a schematic diagram of a grindstone extrusion device. [Figure 13] Figure 13 is a schematic diagram of the grinding wheel magazine. [Figure 14] FIG. 14 is an operation flowchart for changing the grinding wheel and advancing the grinding wheel grinding surface. [Figure 15] FIG. 15 is a diagram illustrating the operation of replacing the grindstone. [Figure 16] FIG. 16 is a diagram illustrating the operation of replacing the grindstone. [Figure 17] FIG. 17 is a diagram illustrating the operation of replacing the grindstone. [Figure 18] FIG. 18 is a diagram illustrating the operation of replacing the grindstone. [Figure 19] FIG. 19 is a diagram illustrating the operation of feeding out the grindstone. DETAILED DESCRIPTION OF THE INVENTION

[0030] Fig. 1 is a perspective view of the grinding wheel oscillating device 1, Fig. 2 is a partial cross-sectional plan view of the grinding wheel oscillating device 1, Fig. 3 is a partial cross-sectional front view of the grinding wheel oscillating device 1, Fig. 4 is a partial cross-sectional front view of a main portion of the grinding wheel oscillating device 1, Fig. 5 is a perspective view of the stone head 4, Fig. 6 is a plan view of the stone head 4, Fig. 7 is a front view of the stone head 4, Fig. 8 is a cross-sectional view of the grinding wheel clamping device 12, Fig. 9 is a perspective view of the grinding wheel management device 5, Fig. 10 is a front view of the grinding wheel management device 5, Fig. 11 is a plan view of the grinding wheel management device 5, Fig. 12 is a schematic diagram of the grinding wheel extrusion device 6, and Fig. 13 is a schematic diagram of the grinding wheel magazine 7. In Figs. 12 and 13, (a) is a perspective view and (b) is a front view. In Fig. 13, (c) is a front view of the magazine body 71.

[0031] The grindstone oscillating device 1 includes a base 11, a main body 2, a front-rear moving device 3, a grindstone oscillating motor 13, a stone head 4, a grindstone management device 5, a grindstone push-out device 6, a grindstone magazine 7, and a control device.

[0032] The base 11 supports the main body 2 so that it can move back and forth in the front-to-rear direction. The "front-to-rear direction" refers to the direction in which the stone head 4 side is the "front" and the front-to-rear movement motor 14 side is the "rear" in Figure 2, and is the direction in which the oscillation axis Sa of the grinding wheel oscillation motor 13 extends.

[0033] The main body 2 is a collective term for the grindstone swing motor 13, the stone head 4, the grindstone management device 5, the grindstone push-out device 6, the grindstone magazine 7, and other parts that move in the front-rear direction relative to the base 11.

[0034] The forward / backward movement device 3 is a device for moving the main body 2 in the forward / backward direction relative to the base 11. The forward / backward movement device 3 has a forward / backward movement motor 14, a ball screw 15, and two linear guides 16, 16. The forward / backward movement motor 14 has a main body (frame) fixed to the base 11, and a shaft connected to a screw shaft 17 of the ball screw 15. The ball screw 15 has a nut fixed to the main body 2, and rotation of the screw shaft 17 moves the nut, moving the main body 2 forward / backward relative to the base 11. The forward / backward movement motor 14 is a servo motor.

[0035] The linear guides 16, 16 have rails 18, 18 fixed to the base 11, and blocks 19, 19 fixed to the main body 2. In the forward / backward movement device 3, the forward / backward movement motor 14 rotates the screw shaft 17 in the forward and reverse directions, causing the nut threaded thereon to move back and forth, and the main body 2 fixed to the nut to move back and forth.

[0036] The grinding wheel oscillation motor 13 is fixed to the main body 2, and its shaft 21 is connected to the stone head 4 via a connecting shaft 22. The grinding wheel oscillation motor 13 rotates forward and backward around the axis of its shaft as an oscillation axis Sa, thereby oscillating the grinding wheel St held by the stone head 4. The grinding wheel oscillation motor 13 is a servo motor.

[0037] 5 to 8, the stone head 4 is composed of a grinding wheel lifting cylinder 24, an arm 26, and a grinding wheel clamping device 12. The grinding wheel lifting cylinder 24 is a double-acting air cylinder. The grinding wheel lifting cylinder 24 is integrated with the connecting shaft 22 via a disk-shaped flange 27. This allows the stone head 4 to swing by the grinding wheel swing motor 13. The grinding wheel lifting cylinder 24 presses the grinding wheel St held by the stone head 4 against the surface to be polished during superfinishing.

[0038] One end of the arm 26 is connected to the rod 25 of the grindstone lifting cylinder 24, and in plan view (FIG. 6), it extends in a direction perpendicular to both the rod 25 and the oscillation axis Sa, and then extends to the opposite side of the flange 27. The arm 26 is connected at its end to the grindstone clamping device 12, which extends as a whole in a direction perpendicular to both the rod 25 of the grindstone lifting cylinder 24 and the oscillation axis Sa.

[0039] The grindstone clamping device 12 comprises an outer shell 28, a clamp rod 29, and a grindstone holding portion 30. The outer shell 28 is elongated overall, and has a grindstone holding hole 31 near one longitudinal end that penetrates parallel to the rod 25. The other longitudinal end of the outer shell 28 has a biasing member accommodating hole 32 with a circular cross section that opens, and at the back of this is a piston accommodating hole 33 with a circular cross section, and further back is a push hole 34 with a circular cross section that opens into the grindstone holding hole 31.

[0040] Clamp rod 29 is a continuous piece of three round rods with different outer diameters. Clamp rod 29 has push rod 35 at one end, whose outer diameter is slightly smaller than the inner diameter of push hole 34 and whose length is slightly longer than push hole 34, piston 36 in the center, whose outer diameter is slightly smaller than the inner diameter of piston accommodating hole 33, and exposed portion 37 at the other end, whose outer diameter is slightly larger than push rod 35 and whose part is exposed from outer shell portion 28.

[0041] The clamp rod 29 has a push rod 35 inserted into a push hole 34 and a piston 36 inserted into a piston accommodating hole 33. A spring retainer 38 with a circular flange-like appearance and a through hole with an inner diameter slightly larger than the outer diameter of the exposed portion 37 is fitted into the connecting portion between the piston 36 and the exposed portion 37. A compression coil spring 39 is housed in the biasing member accommodating hole 32 in the outer shell portion 28, and the opening of the biasing member accommodating hole 32 is closed by a cover 40 that passes through the exposed portion 37. A thick washer-shaped (ring-shaped) locking portion 41 is fixed to the end of the exposed portion 37 that is exposed from the outer shell portion 28.

[0042] The grindstone holding portion 30 is composed of the grindstone holding hole 31, first holding material 42, and second holding material 43, as described above. The first holding material 42 is housed on the side of the grindstone holding hole 31 opposite the side where the push hole 34 is open, and is U-shaped in plan view (FIG. 6), and houses the grindstone St inside. The second holding material 43 is housed on the side of the grindstone holding hole 31 where the push hole 34 is open, and is housed within the grindstone holding hole 31 so that the grindstone St is sandwiched between the first holding material 42 and the second holding material 43. Both the first holding material 42 and the second holding material 43 have flanges at their upper ends to prevent the grindstone from falling.

[0043] The grinding wheel holding portion 30 holds the grinding wheel St contained in the grinding wheel holding hole 31 while sandwiched between the first holding material 42 and the second holding material 43, by the clamp rod 29 pressing the second holding material 43 with the spring force of the compression coil spring 39.

[0044] 9 to 11, the grindstone management device 5 comprises a grindstone position adjusting device 8 and a clamp releasing device 9. The grindstone position adjusting device 8 and the clamp releasing device 9 are integrated into the same frame.

[0045] The grinding wheel position adjustment device 8 has a grinding wheel support 46 and a support cylinder 47. The grinding wheel support 46 is "L" shaped when viewed from the front (FIG. 10), and is equipped with a rectangular columnar position adjustment part 48 that stands at a specific length at the tip of the horizontal part of the "L". The protruding end of the position adjustment part 48 is flat (position adjustment surface). The other end of the "L" shaped grinding wheel support 46 is connected to the rod of the support cylinder 47. The support cylinder 47 is fixed to the frame, and the reciprocating movement of the grinding wheel support 46 as the rod extends and retracts is carried out smoothly by a linear guide.

[0046] The clamp unclamping device 9 has an unclamping portion 51 and an unclamping cylinder 52. The unclamping portion 51 is "L" shaped when viewed from the front (FIG. 10), and has a protrusion 56 that extends horizontally outward at a right angle from near the tip of the part that corresponds to the horizontal part of the "L". The protrusion 56 has a locking groove 53 that is parallel to the part that corresponds to the horizontal part of the "L", and an abutment surface 54 that faces the opposite side from the "near the tip" side. The locking groove 53 has a width and depth slightly larger than the outer diameter of the exposed portion 37 of the clamp rod 29, and the bottom of its cross section is semicircular.

[0047] The vertical portions (upper and lower portions) of the "L" shape of the clamp release part 51 are connected to the rod of the clamp release cylinder 52. The clamp release cylinder 52 is fixed to the frame, and the reciprocating movement of the grinding wheel support 46 as the rod extends and contracts is carried out smoothly by a linear guide 55.

[0048] In the grindstone management device 5, the grindstone support 46 and the clamp release unit 51 are arranged so that they do not overlap in a plan view (FIG. 11) so as to prevent interference between them when the grindstone position adjustment device 8 and the clamp release device 9 are in operation.

[0049] The position adjustment part 48 of the grinding wheel position adjustment device 8 performs its function by contacting the grinding surface of the grinding wheel St held by the grinding wheel holding hole 31 during replacement of the grinding wheel St. The position adjustment part 48 extends in a direction perpendicular to the reciprocating direction at the tip of the grinding wheel support 46 and then stands upright so as to match the position of the grinding wheel St on the stone head 4 tilted at -3°.

[0050] The portion of the clamp release device 9 where the locking groove 53 is provided functions by fitting into the locking portion 37 of the stone head 4. The portion where the locking groove 53 is provided takes into consideration the position of the locking portion 37 on the stone head 4, and the locking groove 53 is provided outward in a direction perpendicular to the reciprocating direction of the clamp release part 51 so that the locking portion 37 can easily fit into it.

[0051] The unclamping unit 51 is a device for releasing the fixation (clamping) of the grinding wheel St in the grinding wheel holding hole 31 by the grinding wheel clamping device 12. As will be described later, the clamp is released when the stone head 4 is tilted -30°, causing the exposed part 37 to fit into the locking groove 53, and the clamp releasing cylinder 52 contracts, causing the abutment surface 54 to engage with the locking part 41. The part of the unclamping unit 51 that engages with the locking part can be formed not as a groove and surface (locking groove 53 and abutment surface 54) but as a large oval, elliptical, or rectangular ring 53B with an abutment surface 54B, and the end of the exposed part 37B of the grinding wheel clamping device 12 that engages with this can be formed as a hook-shaped locking part 41B (see FIG. 10).

[0052] The grindstone management device 5 is provided on the right side of the swing axis Sa on the front surface of the main body 2 in a front view, and the direction of reciprocal movement of the grindstone support 46 and the clamp release part 51 is tilted by 30° clockwise with respect to the horizontal. The frame is fixed to the front surface of the main body 2 (see FIG. 3).

[0053] Referring to FIG. 12, the grindstone extrusion device 6 comprises a push-out cylinder 61, a bracket 62, and a push-out rod 63. The push-out cylinder 61 is equipped with a proximity sensor that detects the position of its piston when it extends to a specific position. The bracket 62 is fixed to the rods 64, 64 of the push-out cylinder 61. The bracket 62 extends in a direction perpendicular to the movement direction of the rods 64, 64 (FIG. 12(a)). The push-out rod 63 is a long, thin rod with a rectangular cross section. The push-out rod 63 is fixed to the end of the bracket 62 fixed to the rods 64, 64, and extends in the movement direction of the rods 64, 64 toward the opposite side of the push-out cylinder 61. The grindstone extrusion device 6 is fixed to the front upper right of the swing axis Sa in a front view, with the push-out rod 63 facing forward and tilted 60° counterclockwise from the horizontal (FIGS. 3 and 4).

[0054] Referring to FIG. 13, the grinding wheel magazine 7 has a transfer cylinder 72, a moving frame 73, a magazine body 71, and a grinding wheel feed cylinder 74. When replacing the grinding wheel St, the transfer cylinder 72 pushes the moving frame 73, the magazine body 71, and the grinding wheel feed cylinder 74 to the grinding wheel replacement location. The moving frame 73 is formed into an "L" shape using thick plates. One end of the moving frame 73 is integrated with the rods 75, 75 of the transfer cylinder 72, with its thickness direction aligned with the movement direction of the rods 75, 75. The other thick plate of the moving frame 73 extends on the opposite side from the transfer cylinder 72.

[0055] The magazine body 71 comprises a grindstone storage section 76, a grindstone feeder 77, and a pressure rod 78. The grindstone storage section 76 has a rectangular parallelepiped appearance. The internal space 79 of the grindstone storage section 76 also has a rectangular parallelepiped shape. The internal space 79 is large enough to store multiple grindstones St lined up in a row (i.e., parallel to each other) in the length direction of the rectangular parallelepiped (the horizontal direction in Figure 4(c)), with their grinding surfaces facing downwards. The grindstone storage section 76 has a push rod insertion port 80 above one end of the rectangular parallelepiped appearance in the length direction, and a grindstone discharge port 81 below the push rod insertion port 80.

[0056] The grindstone feeder 77 is shaped like a substantially rectangular parallelepiped and is disposed in the internal space 79 of the grindstone accommodating section 76. The grindstone feeder 77 is in contact with the grindstone furthest from the push rod insertion port 80 among the grindstones lined up in a row from the end where the push rod insertion port 80 and the grindstone discharge port 81 are provided to the other side.

[0057] The pressure rod 78 penetrates the wall at the end opposite to the side where the push rod insertion port 80 and the grindstone discharge port 81 are provided in the grindstone storage section 76 (the other end in the longitudinal direction), and is connected to the grindstone feeder 77 within the internal space 79.

[0058] The grindstone storage section 76 is fixed to the moving frame 73 so that the outer surface formed by the height and length of the rectangular parallelepiped is positioned such that the push rod insertion port 80 and the grindstone discharge port 81 are spaced apart from the transfer cylinder 72.

[0059] The grinding wheel feed cylinder 74 is fixed to the movable frame 73 on the opposite side from the magazine body 71, with its rod 82 parallel to the pressing rod 78. The rod 82 passes through the movable frame 73 and is connected to the pressing rod 78 by a connecting part 83. This allows the grinding wheel feed 77 to move back and forth within the grinding wheel storage part 76 as the grinding wheel feed cylinder 74 extends and retracts. The grinding wheel feed cylinder 74 retracts when the grinding wheel oscillating device 1 performs superfinishing, and extends when grinding wheels are replenished into the magazine body 71.

[0060] The front wall of the grinding wheel storage section 76 (Figure 13(b)) is made of a transparent acrylic plate that is fixed with a hexagon socket bolt and is removable, so the number of grinding wheels St stored inside can be confirmed from the outside and it is extremely easy to replenish the grinding wheels.

[0061] The grinding wheel magazine 7 is fixed to the upper left of the swing axis Sa on the front surface of the main body 2 when viewed from the front, via a bracket to which the transfer cylinder 72 is integrated, with the reciprocating movement direction of the rod 75 of the transfer cylinder 72 tilted 30° clockwise from the horizontal (see Figures 3 and 4).

[0062] The control device has a microcomputer, a memory device, an interface for input and output, etc., and controls, for example, the movement of the main body 2 by the forward / backward moving device when changing the grinding wheel, the operation of the solenoid valve in the pressurized air supply circuit to the grinding wheel lifting cylinder 24 and the support cylinder 47, etc.

[0063] The grinding wheels used to super-finish the grooves of the inner and outer rings of ball bearings and the groove surfaces of the threaded shaft and nut of ball screws are prone to wear and easily conform to the shape of the surface being polished. To prevent damage, these super-finishing wheels are fixed to a grinding wheel holder, such as a stone head, near the polishing surface (near the oscillating axis). Therefore, after super-finishing one or more workpieces (hereinafter referred to as "workpieces W"), the grinding wheel St is advanced by the amount of wear (the amount the polishing surface recedes = the amount the grinding wheel St has shortened) to prepare for super-finishing the next workpiece. Furthermore, when super-finishing multiple workpieces, the super-finishing wheel becomes too short, making it difficult to secure it to the grinding wheel holder and requiring replacement.

[0064] Next, the replacement of the grinding wheel St in the grinding wheel oscillating device 1 and the operation of feeding out the worn grinding wheel St will be described. Fig. 14 is a flowchart of the operation for replacing the grinding wheel St and feeding out the grinding wheel when superfinishing the outer ring of a ball bearing and the nut of a ball screw, Figs. 15 to 18 are diagrams explaining the operation of replacing the grinding wheel St, and Fig. 19 is a diagram explaining the operation of feeding out the grinding wheel St. Figs. 15 to 19 and the following description apply to the case where the object to be superfinished (workpiece W) is a ball screw nut. The operation (procedure) described below is approximately the same for superfinishing the outer ring of a ball bearing.

[0065] When the control device has completed superfinishing of the groove surface of the workpiece W (Fig. 15(a)), it extends the grinding stone lifting cylinder 24 and raises the arm portion 26 (grinding stone clamping device 12) of the stone head 4 to the extent that the grinding stone St comes out of the thread groove (S1 in Fig. 14, Fig. 15(b)). At this time, the clamp rod 29 of the grinding stone clamping device 12 is horizontal. Hereinafter, for example, "S1 in Fig. 14" will be referred to as "S1".

[0066] The control device controls a workpiece holding device (not shown) that holds and rotates the workpiece W during superfinishing while moving it back and forth along the central axis of the workpiece W, and moves one side of the workpiece W in a direction away from the grinding wheel clamping device 12 (Figure 15(c)).

[0067] Next, the control device causes the front-rear movement device 3 to move the main body 2 backward (S1, Fig. 15(d)). In the grinding wheel oscillating device 1, "backward movement" is an operation that prevents the operations of the grinding wheel management device 5, grinding wheel push-out device 6, and grinding wheel magazine 7 from interfering with the workpiece W and other devices related to the superfinishing of the workpiece W. Therefore, after the workpiece W has been moved away from the grinding wheel clamping device 12, if the superfinishing environment does not impede the operations of the grinding wheel management device 5, grinding wheel push-out device 6, and grinding wheel magazine 7, the control device can omit the backward movement of the grinding wheel oscillating device 1.

[0068] The control device determines whether or not the grinding wheel needs to be replaced based on a flag stored in memory (S2), and if the flag is on, performs the grinding wheel replacement operation. The "flag" for determining whether or not the grinding wheel needs to be replaced is a variable that the control device refers to when determining whether or not the grinding wheel needs to be replaced. "Flag is on" means that when the proximity sensor provided in the extrusion cylinder 61 detects that the piston of the extrusion cylinder 61 has extended to a specific position (the use of the grinding wheel St has reached its limit for the next superfinishing) during the feeding of the grinding wheel St (which was performed by lowering the extrusion rod 63 of the grinding wheel extrusion device 6) (S17) before the most recently completed superfinishing, the control device writes the variable assigned to the stored flag from "0" to "1", for example. Say that it has been replaced (YES in S18).

[0069] First, we will explain the case where the "flag" for determining whether or not the grinding wheel needs to be replaced is "on" (YES in S2), that is, the case where the grinding wheel needs to be replaced. When superfinishing of the workpiece W is completed, the grinding wheel oscillating device 1 is in a state where the clamp release part 51 has advanced (the clamp release cylinder 52 has extended) (Fig. 16(e)). The control device controls the grinding wheel oscillating motor 13 to tilt the stone head 4 clockwise by 30° (=-30°) when viewed from the front (S3, Fig. 16(f)). This action causes the exposed part 37 of the clamp rod 29 in the grinding wheel clamping device 12 of the stone head 4 to fit into the locking groove 53 of the clamp release part 51.

[0070] The control device retracts the clamp release part 51 (S4, (1) in FIG. 16(g)). As the clamp release part 51 retracts, the clamp rod 29 fitted into the locking groove 53 of the clamp release part 51 has its locking part 41 come into contact with the contact surface 54 of the clamp release part 51, and moves together with the clamp release part 51 against the biasing force of the compression coil spring 39. This releases the grinding wheel St from the clamp (fix) by the push rod 35.

[0071] Next, the control device controls the push-out cylinder 61 of the grindstone push-out device 6 to lower the push-out rod 63 (S5, (2) in Figure 16(g)). The push-out rod 63 descends into the grindstone holding hole 31 of the stone head 4, thereby ejecting the grindstone St inside the grindstone holding hole 31 downward. After descending, the push-out rod 63 immediately rises to its original position (S5).

[0072] Next, the control device advances the grinding wheel support 46 of the grinding wheel position adjustment device 8 by extending the support cylinder 47 (bringing it closer to the grinding wheel holding hole 31) (S6, FIG. 16(h)). This operation moves the position adjustment part 48 of the grinding wheel support 46 to the vicinity of the lower opening in the direction through which the grinding wheel holding hole 31 in the grinding wheel clamping device 12 passes (in this case, a direction inclined 30° clockwise from the vertical direction).

[0073] The control device extends the transfer cylinder 72 of the grinding wheel magazine 7 to move the magazine body 71 toward the grinding wheel clamping device 12 of the stone head 4. The movement of the magazine body 71 stops when the grinding wheel discharge port 81 reaches directly above the grinding wheel holding hole 31 (in the direction inclined by 30°) (S7, (1) in Figure 17).

[0074] The control device extends the push cylinder 61 of the grindstone push-out device 6 to lower the push rod 63. The push rod 63 enters the internal space 79 of the grindstone storage section 76 from the push rod insertion port 80 of the magazine body 71, pushes the grindstone St directly below the push rod insertion port 80 out the grindstone discharge port 81, and moves it into the grindstone holding hole 31 of the grindstone clamping device 12 (S8, (2) in FIG. 17). At this time, the lower surface (grinding surface) of the pushed-out grindstone St comes into contact with the upper surface (position adjustment surface) of the position adjustment section 48 of the grindstone position adjustment device 8 of the grindstone management device 5, and the descent of the grindstone St stops.

[0075] The control device retracts the push cylinder 61 to raise the push rod 63 (S9, (1) in FIG. 18(i)). The control device then retracts the transfer cylinder 72 of the grinding wheel magazine 7 to move the magazine body 71 backward (S10, (2) in FIG. 18(i)). Subsequently, or simultaneously with this, the control device operates the clamp release cylinder 52 of the grinding wheel management device 5 to advance the unclamping unit 51 (S10, (1) in FIG. 18(j)). This also advances the abutment surface 54 of the unclamping unit 51, disengaging the locking portion 41 of the grinding wheel clamping device 12 from the abutment surface 54. The new grinding wheel St is then fixed in the grinding wheel holding hole 31 of the grinding wheel clamping device 12 by the clamp rod 29. The control device then rewrites the flag variable stored in memory to "off" (S10). The "off" flag indicates that the grinding wheel St will not be replaced after superfinishing the next workpiece.

[0076] The control device retracts the support cylinder 47 to move the grinding wheel support 46 backward (S11, (2) in FIG. 18(j)).

[0077] Next, the control device controls the grinding wheel oscillating motor 13 to return the stone head 4, which is tilted at -30°, to a horizontal position (S12, Figure 18(k)). The control device advances the main body 2 to the position where superfinishing was performed immediately after superfinishing and before retreating (S13). After this, the control device moves the workpiece holding device (not shown), which holds a new workpiece W, to a position where superfinishing processing will be performed. This movement of the workpiece holding device causes the new grinding wheel St to enter the inside of the workpiece W. The control device retracts the grinding wheel lifting cylinder 24 to move the grinding surface of the grinding wheel St into the thread groove of the workpiece W (S13), and oscillates the grinding wheel oscillating motor 13 to start superfinishing.

[0078] Next, the operation of the grindstone oscillating device 1 when the "flag" for determining whether grindstone replacement is necessary is "off" (NO in S2), that is, when only the grindstone St that does not require replacement is fed will be described.

[0079] When superfinishing of the workpiece W is completed, the control device extends the grinding wheel lifting cylinder 24 to raise the grinding wheel clamping device 12 (S1, see FIG. 15(b)). Next, the control device moves the workpiece holding device (not shown) in a direction in which the workpiece W moves away from the grinding wheel clamping device 12 (FIG. 15(c)). Next, the control device advances the grinding wheel support 46 of the grinding wheel position adjustment device 8 by extending the support cylinder 47 (S14, FIG. 19(a)). Next, the control device controls the grinding wheel swing motor 13 to tilt the stone head 4 clockwise by 30° when viewed from the front (S15, (1) in FIG. 19(b)). This action causes the exposed portion 37 of the clamp rod 29 of the grinding wheel clamping device 12 of the stone head 4 to fit into the locking groove 53 of the clamp release portion 51.

[0080] The control device retracts the clamp release unit 51 (S16, (2) in FIG. 18(b)), releasing the clamp rod 29 from fixing the grinding wheel St in the grinding wheel holding hole 31. The control device then causes the extrusion cylinder 61 of the grinding wheel extrusion device 6 to perform an extending operation, thereby lowering the extrusion rod 63 (S17, FIG. 19(c)). The extrusion rod 63 pushes the grinding wheel St in the grinding wheel holding hole 31 downward, and continues to descend until the grinding surface of the grinding wheel St hits the upper surface (position adjustment surface) of the position adjustment unit 48 of the grinding wheel support 46 and the movement stops.

[0081] At this time, when the proximity sensor provided on the extrusion cylinder 61 detects that the piston of the extrusion cylinder 61 has extended to a specific position (YES in S18), the control device changes the variable "0" of the flag for determining whether or not the grinding wheel needs to be replaced, stored in the memory device, to "on = 1" (S19).

[0082] Thereafter, the control device raises the push rod 63, and then (extends the clamp release cylinder 52) moves the clamp release part 51 forward (S20), and clamps the grinding wheel St that has been advanced by the amount of wear into the grinding wheel holding hole 31.

[0083] The control device retracts the support cylinder 47 to move the grinding wheel support 46 backward (S11, (2) in FIG. 18(j)).

[0084] Next, the control device controls the grinding wheel oscillating motor 13 to return the stone head 4, which is tilted at -30°, to a horizontal position (S12, Figure 18(k)). The control device advances the main body 2 to the position where superfinishing was performed immediately after superfinishing and before retreating (S13). After this, the control device moves the workpiece holding device, which holds a new workpiece W, to the position where superfinishing treatment will be performed. This movement of the workpiece holding device causes the new grinding wheel St to enter the workpiece W. The control device retracts the grinding wheel lifting cylinder 24 to move the grinding surface of the grinding wheel St into the thread groove of the workpiece W (S13), and superfinishing begins.

[0085] The above has explained the replacement operation of the grinding wheel St using the nut of a ball screw as an example, but the basic configuration of the grinding wheel oscillating device 1 can also be applied as is to the superfinishing of the screw shaft of a ball screw and the inner ring of a ball bearing, allowing the replacement operation and feeding operation of the grinding wheel to be performed.

[0086] In the grinding wheel oscillating device 1, the functions (devices) necessary for grinding wheel replacement are separated from the stone head 4, making the oscillating parts lighter and reducing the load on the grinding wheel oscillating motor 13. In addition, in the grinding wheel oscillating device 1, the devices related to grinding wheel replacement are fixed to the main body 2 and do not oscillate at high speed, so malfunctions caused by oscillation are less likely to occur. Furthermore, by separating the devices for each function necessary for grinding wheel replacement, the grinding wheel oscillating device 1 makes it easy to inspect and repair each device, and stable grinding wheel replacement operations can be expected.

[0087] In the above-described embodiment, the stone head 4, the grindstone management device 5, the grindstone push-out device 6 and the grindstone magazine 7 may have other shapes and configurations that fulfill their functions.

[0088] Additionally, the grindstone oscillating device 1 and each component or the overall structure, shape, dimensions, number, material, etc. of the grindstone oscillating device 1 can be modified as appropriate in accordance with the spirit of the present invention. [Industrial Applicability]

[0089] The present invention can be used in a method and device for replacing a superfinishing grindstone when superfinishing the inner and outer rings of a ball bearing and the groove surfaces of a ball screw. [Explanation of symbols]

[0090] 1 Grindstone oscillation device 2 Main unit 6 Grindstone extrusion device 8 Grindstone position adjustment device 9. Clamp release device 11 Foundation 12 Grinding wheel clamping device (grinding wheel fixing device) 13 Grindstone oscillation motor (oscillating motor) 24 Grindstone lifting cylinder (air cylinder) 29 Clamp rod 31 Grindstone holding hole 34 Push Hole 39 Compression coil spring (biasing material) 41,41B Locking part (fixing release locking part) 48 Position adjustment section (position adjustment surface) 54, 54B Contact surface (engaging part) 56 Protrusion 63 Extrusion rod 71 Magazine body 80 Push-out rod insertion port 81 Grinding wheel outlet St grinding stone

Claims

1. A method for replacing a grinding stone in a grinding stone oscillating device for performing superfinishing by oscillating a grinding stone fixing device that fixes a grinding stone using an oscillating motor, comprising: The grindstone is fixed to the grindstone holding hole in the grindstone fixing device, through which the grindstone is passed and held, by urging a rod-shaped clamp rod housed in a push hole of the grindstone fixing device toward the grindstone holding hole by an urging member; The clamp rod is exposed from the grindstone fixing device on a side opposite to the biasing direction of the biasing member, and a fixing release locking portion is provided near the exposed end of the clamp rod. a main body for holding the swing motor is provided with an engaging portion that moves back and forth and is capable of engaging with the fixing release locking portion when moving forward; The grindstone fixing device is rotated in one of the forward and reverse directions by the swing motor to bring the fixing release engaging portion and the engaging portion into an engageable state; Next, the engaging portion is moved forward to engage with the release locking portion, and the clamp rod is moved in the opposite direction to the biasing direction to release the grindstone from the grindstone holding hole. a push rod of a grindstone push-out device integrated with the main body is inserted through an opening of the grindstone holding hole to eject the held grindstone; The push rod is retracted from the grindstone holding hole, a position adjusting surface of a grindstone position adjusting device integrated with the main body is moved to the vicinity of an opening in the grindstone holding hole on the opposite side to the opening into which the push rod is inserted; a magazine body that is integrated with the body and can accommodate a plurality of replacement grinding stones is moved near the opening into which the push rod is inserted; the push rod is inserted into the magazine body, and one of the replacement grindstones is pushed into the grindstone holding hole until its grinding surface abuts against the position adjustment surface; The push rod is retracted from the magazine body, and the engaging portion is returned to release the engagement with the fixing release locking portion, thereby fixing a new grindstone in the grindstone holding hole. The position adjustment surface is moved away from the opening of the grindstone holding hole, The grindstone fixing device is rotated in the other direction, forward or backward, by the swing motor to release the engagement between the fixing release locking portion and the engagement portion. A method for replacing a superfinishing grindstone.

2. a cross section of a portion of the clamp rod exposed to the outside from the other end of the pressing hole is circular; The fixing release locking portion is formed in a ring shape like a thick washer, The engaging portion is formed by a locking groove into which the exposed portion of the clamp rod can be fitted, and a contact surface on the forward movement side thereof that can engage with the release locking portion.

2. A method for replacing a superfinishing grindstone according to claim 1.

3. a grindstone fixing device that is swung by a swing motor and has a grindstone holding hole at one end in the longitudinal direction of its elongated shape, through which a superfinishing grindstone can be passed and fixed; a main body that holds the swing motor; a grindstone position adjusting device including a position adjusting surface that is movable to the vicinity of an opening in the grindstone holding hole that is on the grinding surface side of the grindstone and faces the opening side; a clamp release device having an engagement portion capable of reciprocating; a magazine body that accommodates a plurality of new replacement grinding wheels in a row, has a push rod insertion port on the side opposite to the grinding surface of the end of the grinding wheel, and has a grinding wheel discharge port on the side of the grinding surface, both of which penetrate from the inside to the outside, and is movable to the vicinity of the opening of the grinding wheel holding hole on the side opposite to the opening on the grinding surface side; a grindstone pushing-out device including a pushing rod for entering the magazine body through the pushing rod insertion port and pushing out the endmost grindstone in the magazine body from inside the magazine body; a control device that controls the operations of the swing motor, the grindstone position adjusting device, the clamp releasing device, the magazine body, and the grindstone pushing device; and The grindstone fixing device is One end opens into the grindstone holding hole, and the other end extends in the longitudinal direction and opens. A push hole and a push hole that is movably accommodated in the push hole and exposed to the outside from the other end of the push hole; an elongated clamp bar having a release latch at its extended end; The clamp rod is attached to the grindstone holding hole side to fix the grindstone in the grindstone holding hole. a biasing member for biasing the and The clamp release device is When the engaging portion engages with the fixing release locking portion and moves forward, the clamp rod The biasing member is configured to move the object in the opposite direction to the biasing direction of the biasing member. The swing motor rotates the grindstone fixing device in either the forward or reverse direction, thereby bringing the fixation release locking portion and the engaging portion into an engageable state, and when the engaging portion is subsequently moved forward, the engaging portion engages with the fixation release locking portion, thereby releasing the fixation of the grindstone in the grindstone holding hole, When the engaging portion moves back, the engaging state is restored and the grindstone in the grindstone holding hole is fixed to the grindstone fixing device, and when the swing motor rotates the grindstone fixing device in the other direction, the engaging state is released. A superfinishing grindstone changing device characterized by the above.

4. The grindstone position adjusting device, the clamp releasing device, the magazine body, and the grindstone pushing device are integrated into the body.

4. The grinding wheel changing device according to claim 3.

5. a base that supports the main body so that the main body can move back and forth in the direction of the rotation axis of the swing motor; 5. The grinding wheel changing device according to claim 3 or 4.

6. The clamp release device and the grindstone position adjustment device are supported on the same frame, and the frame is fixed to the main body.

6. The grinding wheel changing device according to claim 5.

7. The grindstone fixing device is connected to the swing motor via an air cylinder that reciprocates the grindstone fixing device in the direction in which the grindstone holding hole penetrates.

5. The grinding wheel changing device according to claim 3 or 4.

8. When viewed from the direction in which the oscillation shaft of the oscillation motor extends, a direction in which the engaging portion of the clamp release device moves forward is the same as a direction in which the engaging portion of the clamp release device moves toward the vicinity of an opening of the grinding stone holding hole of the magazine body on the side opposite to the opening on the grinding surface side, The direction in which the push rod of the grindstone push-out device moves into the magazine body is perpendicular to the direction in which the engaging portion moves forward.

5. The grinding wheel changing device according to claim 3 or 4.

9. a cross-sectional shape of a portion of the clamp rod exposed to the outside from the other end of the push hole is circular; The release locking portion is a ring-shaped portion like a thick washer, The engaging portion has an engaging groove into which the exposed portion of the clamp rod can be fitted, and an abutment surface on the forward movement side thereof that can engage with the fixing release engaging portion.

5. The grinding wheel changing device according to claim 3 or 4.

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