JP2014030871A - Super-finishing grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a super-finishing grinding device capable of grinding a large-sized work, by easily changing a rocking angle of a super-finishing grinding wheel.SOLUTION: A super-finishing grinding device 1 according to the present invention is configured by rockably connecting a grinding wheel holding device 4 to a parallel link, which is formed by connecting two rocking links 11a and 11b and two rocking arms 12a and 12b with four rocking shafts 14-17, with use of two rocking shafts 352 and 353 juxtaposed in parallel to a row of the rocking shafts in the rocking arms. A super-finishing grinding wheel 39 held by the grinding wheel holding device vibrates by servomotors 41 and 42 as a driving source, a ball screw 21 formed of a screw shaft 211 and a nut 212 and rotating the screw shaft by the servomotors, and connection means 23 for unfixably connecting the rocking arms to the nut.

Description

  The present invention relates to a super finishing grinding apparatus capable of performing a process for increasing the smoothness of the surface of a spherical roller used in, for example, a spherical roller bearing.

Spherical roller bearings have spherical spherical rollers that swell in the center in the axial direction, and those that are arranged in two rows are self-aligning, so they are suitable for large machinery equipment that is prone to mounting errors. Yes. The higher the smoothness of the surface of the spherical roller, the higher the durability of the spherical roller bearing, and the vibration and noise of the used rotating equipment are reduced.
Conventionally, a super finishing grinding device 8 shown in FIG. 13 is used for the smoothing process of the surface of the spherical roller. In the super finishing grinding device 8, two swing arms 81 and 82 and two swing links 83 and 84 are connected in parallel by four swing shafts 85 to 88, and the lower ends of the swing arms 81 and 82 are held. The shafts 89 and 90 are swingably supported. A grindstone holding device 92 that holds the superfinishing grindstone 91 is swingably held by swing links 83 and 84 by two swing shafts 93 and 94.

In the super finishing grinding device 8, a grindstone holding device 92, rocking links 83 and 84, and rocking arms 81 and 82 are arranged from the front to the back in FIG. One swing arm 81 is connected to a drive motor 97 by a connecting rod 96 via a swing shaft 95.
The drive motor 97 and one end of the connecting rod 96 are coupled to an eccentric cam 99 that rotates about the rotation center P <b> 1 of the drive motor 97 by a coupling shaft 100.

The superfinishing grinding device 8 changes the rotation of the drive motor 97 to reciprocating motion by the connecting rod 96 and operates the four-joint parallel link mechanism by the swinging arms 81 and 82 and the swinging links 83 and 84. 91 high-speed vibration is realized.
By the way, the amplitude (oscillation angle) of the superfinishing grindstone 91 is changed depending on the size and shape of the superfinished object (workpiece) W. Since the swing angle of the super finishing grinding device 8 is determined by the distance R1 between the rotation center P1 of the eccentric cam 99 and the center P2 of the connecting shaft 100, the clamp bolts 98, 98, 98 are used to change the swing angle. Loosen and rotate the worm 102 by the adjustment knob 101 to rotate the eccentric cam 99 around the center P3, and the distance between the connecting shaft 100 (the center P2) and the rotation center P1 becomes a value R2 corresponding to the changed swing angle. Work to change was necessary.

In the super finishing grinding device 8, the reciprocating motion of the connecting rod 96 is limited to a single string motion, and the speed of the swinging process of the super finishing grindstone 91 cannot be varied in various ways.
On the other hand, an AC servo motor is used as the drive motor, and the end of the swing arm that is swingably supported by the holding shaft is connected to the drive shaft of the AC servo motor by a timing belt, so that the drive shaft is forward and reverse There has been disclosed a grinding apparatus for performing super finishing, in which a parallel link mechanism is operated by rotating (Patent Document 1).

Japanese Patent No. 4531100

The grinding apparatus disclosed in Patent Document 1 can easily change the rocking angle of the superfinishing grindstone by adopting an AC servo motor, and has a high degree of freedom in selecting the rocking speed.
However, as mentioned above, spherical roller bearings are also used in large machinery, and spherical roller bearings used for large diameter bearings require large spherical rollers and large parallel link mechanisms for grinding devices. Become. In the grinding device disclosed in Patent Document 1, the swing arm and the swing link are reduced in weight. However, if the parallel link mechanism becomes larger (the swing arm becomes longer), the swinging arm and the swing link are moved accordingly. The inertial force is increased, and an unbalanced high-power drive motor is required for stable driving.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a super finishing grinding apparatus that can easily change the swing angle of a super finishing grindstone and can grind a large workpiece.

  The super finishing grinding apparatus according to the present invention includes two parallel links in which two swing links and two swing arms are connected by four swing shafts, and are arranged in parallel with the swing shaft of the swing arm. The grindstone holding device is pivotably connected by the swing shaft. The super-finishing grindstone held by the grindstone holding device has a servo motor as a drive source, a ball screw that is constituted by a screw shaft and a nut, and the screw shaft is rotated by the servo motor, and a swing arm that is fixedly connected to the nut. It vibrates with the connecting means.

“Non-fixed connection” means a state in which the relative positions of the nuts are allowed to change so that the swinging arm connected to the nut does not prevent the linear movement of the nut passing through the screw shaft. Say.
The connecting means in the superfinishing grinding apparatus is realized by a connecting rod having one end connected to the nut and the other end connected to the swing arm.

In addition, the connecting means in the superfinishing grinding apparatus includes a connecting pin moving hole that is a hole penetrating either the nut or the swing arm, and a connecting pin moving hole that is integrated with either the nut or the swing arm. It is also realized by a rod-like connecting pin fitted so that the nut can be linearly moved.
One servo motor as a drive source is preferably connected to each end of the screw shaft.

  The superfinishing grinding apparatus preferably includes a cover that separates the ball screw and the grindstone holding device between both ends of the screw shaft. The cover is provided with either a rod-shaped guide rail extending parallel to the screw shaft or a rail guide groove into which the guide rail is fitted and slidable, and a member integrated with the nut or the nut One of the guide rail and the rail guide groove is provided on the other side.

  According to the present invention, it is possible to provide a super finishing grinding apparatus that can easily change the swing angle of a super finishing grindstone and can grind a large workpiece.

FIG. 1 is a front sectional view of the superfinishing grinding apparatus. FIG. 2 is an enlarged view of the link driving unit. FIG. 3 is a plan sectional view of the superfinishing grinding apparatus. FIG. 4 is a side sectional view of the superfinishing grinding apparatus. FIG. 5 is a diagram showing how the grinding wheel grinding surface position is adjusted in the grinding wheel holding device. FIG. 6 is an operation diagram of the super finishing grinding apparatus in super finishing of the spherical roller W curved surface. FIG. 7 is a diagram showing the relationship between the positioning jig and the reference pin. (A) is sectional drawing, (b) is the EE arrow line view of (a). FIG. 8 is a front view of another superfinishing grinding apparatus. FIG. 9 is a front view of another superfinishing grinding apparatus. FIG. 10 is a diagram showing the relationship between the irregularly shaped workpiece and the superfinishing grindstone. FIG. 11 is a cross-sectional plan view of a superfinishing grinding apparatus having another link driving unit. FIG. 12 is a DD arrow view in FIG. FIG. 13 is a schematic view of a conventional superfinishing grinding apparatus.

  1 is a front sectional view of the superfinishing grinding apparatus 1, FIG. 2 is an enlarged view of the link drive unit 2 of FIG. 1, FIG. 3 is a plan sectional view of the superfinishing grinding apparatus 1, and FIG. It is sectional drawing. 1 is a cross-sectional view taken along line AA in a cross section perpendicular to FIG. 4 including a broken line connecting A1 to A10 in FIG. 3 is a cross-sectional view taken along line B-B in a cross section perpendicular to FIG. 1 including a broken line connecting B1 to B6 in FIG. 4 is a cross-sectional view taken along the line C-C in a cross section perpendicular to FIG. 3 including a broken line connecting C1 to C6 in FIG.

The super finishing grinding device 1 includes a link mechanism unit 3, a link driving unit 2, a grindstone holding device 4, a driving device 5, a control device, and the like.
The link mechanism unit 3 includes two swing links 11a and 11b, two swing arms 12a and 12b, a link base 13, and the like.
The two swing links 11a and 11b are elongated rods having a rectangular cross-sectional shape, and the two shapes and sizes are the same.

Each of the two swing arms 12a and 12b is a rod having a rectangular cross section, and the long side of the rectangular cross section gradually increases from one end of the rod toward the other end. The two swing arms 12a and 12b have the same shape and size.
Each of the swing arms 12a and 12b is connected to a different end of one swing link 11a so as to be swingable by swing shafts 14 and 15, respectively. Further, the swing arms 12a and 12b are pivotally connected to the different ends of the other swing link 11b by swing shafts 16 and 17 at intermediate portions in the longitudinal direction. The two swing links 11a and 11b are located on the same side with respect to the two swing arms 12a and 12b.

The other ends of the swing arms 12a and 12b are rotatably held by the link base 13 by holding shafts 18 and 19, respectively.
The axis of the oscillating shafts 14 and 16 and the holding shaft 18 in one oscillating arm 12a exists in one virtual plane, and the axis of the oscillating shafts 15 and 17 and the holding shaft 19 in the other oscillating arm 12b. Exists in a virtual plane parallel to a virtual plane including each axis of one swing arm 12a.

One swinging arm 12 b has a drive transmission shaft 121 parallel to the swinging shafts 15, 17 between the two swinging shafts 15, 17. The drive transmission shaft 121 extends to the side opposite to the side where the swing links 11a and 11b are located with respect to the swing arm 12b.
The link base 13 is held in a prismatic column (not shown) so as to be movable up and down. The column is provided with a ball screw having a screw shaft extending in the vertical direction, and a servomotor for driving the screw shaft of the ball screw, and the link base 13 moves up and down integrally with a nut of the ball screw. The link base 13 is connected to the other end of the chain to which a balance weight substantially equal to the weight of the entire link mechanism 3 including the link base 13 is connected at one end. A sprocket that meshes with a chain is provided at the upper end of the column. The sprocket functions as a fixed pulley, and smoothly moves the link base 13 up and down by a ball screw. Further, the link base 13 is moved to an arbitrary height by a servo motor fixed to the column and is stopped.

The link mechanism section 3 is a parallel link mechanism constituted by the above-described elements, in which the two swing links 11a and 11b are parallel to each other and the two swing arms 12a and 12b are parallel to each other.
The link drive unit 2 includes a ball screw 21, a nut support member 22, a connecting rod 23, a guide rail 24, and the like.

The ball screw 21 is a general one made of a screw shaft 211, a nut 212, a plurality of steel balls held in the nut 212, and the like.
The screw shaft 211 is disposed horizontally, and both ends thereof are coupled to the drive shafts of two servo motors 41 and 42, which will be described later, fixed to the frame of the superfinishing apparatus 1 via coupling cases 43 and 44, respectively. ing.

  The nut support member 22 has a wide U-shaped groove across the center and a cross-sectional shape as a whole. The nut 212 is integrated with a concave portion (hereinafter referred to as a “concave portion 221”). Fixed). The recess 221 extends in parallel with a hole (hereinafter referred to as “screw shaft hole”) through which the screw shaft 211 of the nut 212 passes. The nut support member 22 includes rail guide grooves 222 and 222 which are grooves extending in parallel with the screw shaft hole on both sides of the recess 221 with the nut 212 interposed therebetween. The rail guide groove 222 has a rectangular cross-sectional shape.

The nut support member 22 has a connecting rod rotation shaft 223 extending in the direction perpendicular to the imaginary plane including the two rail guide grooves 222 and 222 (the bottoms thereof) on the side opposite to the side on which the nut 212 is fixed. Therefore, the connecting rod rotation shaft 223 and the screw shaft hole have an angle of 90 degrees in plan view (FIG. 3).
The connecting rod 23 is a thick plate having a substantially rectangular cross section, and one end is rotatably connected to the connecting rod rotating shaft 223 and the other end is rotatably connected to the drive transmission shaft 121 of the swing arm 12b. Has been. In the superfinishing grinding apparatus 1, the connecting rod 23 is disposed on the opposite side of the swing links 11a and 11b with the swing arm 12 interposed therebetween.

  By the way, in the superfinishing grinding apparatus 1, a cover 31 that covers between both ends of the screw shaft 211 is provided in order to prevent the grinding powder generated by the superfinishing process from scattering to the ball screw 21 and biting into the ball screw 21. The cover 31 has a substantially “U” -shaped cross-section perpendicular to the longitudinal direction thereof, that is, the axial direction of the screw shaft 211. This is a sufficient size that does not hinder movement along the screw shaft 211.

  One guide rail 24 is fixed to each of two opposing “U” -shaped side surfaces of the cover 31. The two guide rails 24 and 24 have the same shape and size of a rectangular bar-shaped cross section, and the distance between them is equal to the distance between the rail guide grooves 222 of the nut support 22. The cross-sectional shape of the guide rail 24 is such that the guide rail 24 fits snugly into the rail guide groove 222 of the nut support member 22 and can slide with respect to the rail guide groove 222. The guide rail 24 is provided at the center in the longitudinal direction of the cover 31, and its length corresponds to the swing range of the swing arm 12b connected via the connecting rod 23 (if the swing range is an arc, its string Length). The guide rail 24 improves the operation accuracy and durability of the ball screw 21 by sliding in the rail guide groove 222 and smoothly moving the nut support member 22. The cover 31 is fixed to the coupling cases 43 and 44 of the servomotors 41 and 42 that are connected to both ends of the screw shaft 211, respectively.

FIG. 5 is a diagram showing how the grinding wheel grinding surface position is adjusted in the grinding wheel holding device 4.
The grindstone holding device 4 includes a base 35, a first interposition part 36, a second interposition part 37, and a grindstone holding part 38.
The base 35 has a trapezoidal ant 351 having a short bottom surface (upper bottom) and a long bottom surface (lower bottom) as a protrusion, and protrudes vertically on one surface. The base 35 oscillates by the oscillating shafts 352 and 353 to the oscillating shafts 352 and 353 so that the direction in which the dovetail 351 extends is orthogonal to the oscillating links 11a and 11b and the upper and lower ends thereof are different from each other. Supported as possible.

  As for the 1st interposition part 36, the dovetail groove 361 which inserts the dovetail 351 of the base 35 is provided in one surface. The dovetail groove 361 is fitted with the dovetail 351 of the base 35 using the give 363. The first interposition part 36 can be moved up and down with respect to the base 35 by moving the dovetail groove 361 fitted to the dovetail 351. The vertical movement of the first interposition part 36 is limited by tightening the hexagon socket head bolt 364 screwed into the female thread of the give 363 and pulling the give 363 to the first interposition part. The first interposition part 36 includes an ant 362 extending in the vertical direction on the other surface.

The 1st interposition part 36 and the 2nd interposition part 37 are integrated so that it can expand-contract in the up-down direction by the combination of the dovetail 362 and the dovetail groove 371. FIG. The second interposition part 37 and the grindstone holding part 38 are integrated in a horizontal direction (longitudinal direction of the rocking links 11a and 11b) so as to expand and contract by a combination of the dovetail 373 and the dovetail groove 382.
For example, when the curvature of the processed surface of the object to be ground is small (the curvature radius is large), the grindstone holding device 4 raises the grindstone holding portion 38 to increase the distance from the vibration center of the grinding surface of the superfinishing grindstone 39. On the contrary, when the curvature of the machining surface is large, the grindstone holding portion 38 can be lowered to reduce the distance from the vibration center of the grinding surface of the superfinishing grindstone 39.

Thus, the superfinishing grinding apparatus 1 can move the grindstone holding device 4 that holds the superfinishing grindstone 39 up and down in accordance with the processing curvature of the object to be ground.
The super finishing grinding device 1 can cope with various grinding objects having different curvatures of the machining surface by moving the link base 13 up and down with respect to the column and moving the grindstone holding device 4 up and down. The vertical movement of the link base 13 is performed by a servo motor, so that the grindstone holding device 4 can be raised when the workpiece after grinding is taken out, and the grindstone holding device 4 can be accurately lowered when an unground workpiece is set. .

  The driving device 5 includes two servo motors 41 and 42. The servo motors 41 and 42 have their rotation shafts connected to different ones at both ends of the screw shaft 211 of the ball screw 21 via cup link cases 43 and 44. One servo motor 41 may be referred to as a master servo motor 41. The other servo motor 42 may be referred to as a slave servo motor 42.

  The servo motors 41 and 42 rotate the connected screw shaft 211 and move the nut 212 screwed to the screw shaft 211 in the horizontal direction. The nut 212 moves the connected connecting rod 23 in the same direction as its own moving direction, and the connecting rod 23 rotates the connected swing arm 12 b around the holding shaft 19. The servo motors 41 and 42 cooperate to repeat the forward and reverse rotations of the screw shaft 211 to reciprocate the nut 212 and swing the link mechanism portion 3 connected to the connecting rod 23 around the holding shafts 18 and 19. (See FIG. 6).

The control device includes a controller and a servo amplifier.
The controller inputs super finishing machining conditions, calculation results, RAM output data and servo amplifier control program, RAM for calculation processing, storage device such as large capacity magnetic disk, super finishing machining conditions, etc. In addition, an input / output device (touch panel) for displaying the status of superfinishing processing, an alarm device for notifying abnormality, and the like.

The controller instructs the operating conditions of the servo motors 41 and 42 to the servo amplifier to control these operations.
Next, the operation of the superfinishing grinding apparatus 1 during superfinishing will be described.
FIG. 6 is an operation diagram of the superfinishing grinding apparatus 1 in superfinishing of the curved surface of the spherical roller W. FIG. 6A is a diagram in which the nut 212 has moved to the right end and the superfinishing grindstone 39 has swung by the angle θ, and FIG. 6C is a diagram in which the nut 212 has moved to the left end and the superfinishing grindstone 39 has swung by the angle −θ. .

  First, the operating conditions of the superfinishing grinding apparatus 1 are input from the input / output device to the controller. The operating conditions include an angle (vibration angle) θ for vibrating the superfinishing grindstone 39, a vibration frequency, a vibration speed, and a time for grinding one spherical roller W (hereinafter also referred to as “work W”). The super finishing grinding device 1 using the servo motors 41 and 42 as a drive source causes the vibration of the super finishing grindstone 39 to generate a single-string motion (single vibration, It is possible to change the vibration speed in a multistage manner in one cycle of vibration, not in the sine curve), and to change the vibration speed in stages during one cycle of grinding. These series of operating conditions are not input each time, but are stored in the storage device as individual programs and the corresponding program is called each time the work W is changed, or the work is handled by handling variables in a single program. A series of parameters stored for each W may be read from the storage device.

“Vibration” explains the movement of the superfinishing grindstone 39, and “oscillation” explains the movement of the link mechanism 3 or this component, but these are not strictly distinguished. Absent.
The workpiece W is conveyed between two rolls 51 and 51 (see FIG. 4) that are horizontally aligned and rotated in the same direction, and start rotating. Compressed air having a predetermined pressure for extending the rod is supplied to the air cylinder 385, and the grinding surface of the superfinishing grindstone 39 is pressed against the curved surface of the workpiece W. At the same time, the controller controls the servo motors 41 and 42 to repeat normal and reverse rotations at a rotation speed corresponding to the set vibration speed, and starts grinding. The controller stores the origin position of the nut 212 (position where the tilt angle of the swing arm 12b is zero) as the rotation angle in the master servo motor 41, and the nut 212 reciprocates between the distances ± X on both sides of the origin position. A drive command for the servo motors 41 and 42 is issued to the servo amplifier so as to repeat the movement. The distance ± X is a moving distance of the nut 212 for vibrating the superfinishing grindstone 39 at an angle ± θ.

The drive device 5 uses the servo motor 41 as a master to perform position control, and the other servo motor 42 performs master-slave control in charge of only the driving force.
Setting (memory) of the origin position is started by moving the nut 212 so that the vertical rods 12a and 12b are completely vertical.
Referring to FIG. 7, when the vertical rods 12 a and 12 b are completely vertical, the positioning jig 45 is moved to the vertical rod 12 b side, and the cylinder fitted in the hole 46 provided in the vertical rod 12 b. The reference pin 47 having a shape is received in a groove provided at the end of the positioning jig 45 on the vertical rod 12b side. This groove has a semicircular cross section with an inner diameter slightly larger than the outer diameter of the reference pin 47. When the positioning jig 45 is moved horizontally toward the vertical rod 12b and the reference pin 47 is fitted in the groove, the vertical rods 12a and 12b are completely vertical.

That is, whether or not the vertical rods 12a and 12b are vertical is whether or not the reference pin is inserted into the hole provided in the vertical rod 12a in a state in which the vertical rods 12a and 12b are accommodated in a groove having a semicircular cross section in the jig fixed to the ring base 13. Judged by no.
When the vertical position of the vertical rods 12a and 12b is confirmed, the positioning jig 45 is moved to the position where the reference pin 47 comes out from the groove (to the left in FIG. 7).

The position where the vertical rods 12a, 12b are vertical is stored as the origin position of the nut 212 (inclination angle θ = 0 °) in association with the encoder value of the servo motor 41 at this time.
When the vertical rods 12a and 12b are inclined at the inclination angle θ, the nut 212 is moved to the distance X from the origin position corresponding to the inclination angle θ calculated in advance. Next, the nut 212 is returned to the origin position, and further moved by a distance X in the opposite direction, so that the vertical rods 12a and 12b are inclined to the inclination angle −θ.

By repeating this series of movements of the nut 212, the super finishing grindstone 39 swings.
The nut 212 reciprocally swings the swing arm 12 b via the connecting rod 23. The swing arm 12b reciprocally swings the entire link mechanism unit 3. The grindstone holding device 4 supported on the rocking links 11a and 11b by the rocking shafts 352 and 353 repeats reciprocating rocking within the set vibration angle ± θ, similarly to the rocking arms 12a and 12b.

  The rocking center (axis) O of the grindstone holding device 4 appears parallel to the holding shafts 18 and 19 of the rocking arms 12a and 12b and in the same virtual plane. The super-finishing grindstone 39 is dented with the same curvature as the curvature of the generatrix of the barrel-shaped workpiece (spherical roller) W whose center in the axial direction swells on the peripheral surface, and is rocked between the holding shafts 18 and 19. It is held between the moving link 11b and vibrates in the same direction as the swinging link 11b.

By the reciprocating swing of the grindstone holding device 4, the ground surface of the superfinishing grindstone 39 held vibrates while pressing the curved surface of the rotating workpiece (spherical roller) W, and superfinishing is performed.
The controller controls the grinding process according to the input operating conditions, and when all the grinding processes are completed (or when the set machining time has elapsed), the controller controls the servo motors 41 and 42 to move the nut 212 to the origin.

At the same time, the pressurization of the super finishing grindstone 39 is stopped, the servo motor provided in the column is rotated while the position of the super finishing grindstone 39 is maintained, and the link base 13 is raised by the ball screw. The ground workpiece W is replaced with an unground workpiece W after the link base 13 is lifted.
Since the super finishing grinding apparatus 1 uses the servo motors 41 and 42, the vibration angle and vibration speed of the super finishing grindstone 39 can be easily changed by data input or program change.

Further, the super finishing grinding device 1 drives the position away from the holding shaft 19 that is the center of swinging of the swinging arm 12b via the ball screw 21 and the connecting rod 23 (for the fulcrum, the force point, and the working point). A large link mechanism can be operated with a small force (from the mutual relationship), and a large workpiece can be ground with a small output motor.
The super finishing grinding apparatus 1 can easily change the grinding conditions from a touch panel (operation panel) or the like.

8 and 9 are front views of other superfinishing grinding apparatuses 1B and 1C.
The super finishing grinding device 1B includes a link mechanism unit 3, a link driving unit 2, four grindstone holding devices 4B, 4B, 4B, 4B, a driving device 5, a control device, and the like.
In the super finishing grinding device 1B, four grindstone holding devices 4B, 4B, 4B, 4B are connected to two swing links 11a, 11b in a swingable manner. Further, the grindstone holding device 4B is designed to be elongated compared to the grindstone holding device 4 of the superfinishing grinding device 1 in order to enable four parallel installations. Except for this, the superfinishing grinding apparatus 1B has the same structure and operation as the superfinishing grinding apparatus 1 described above. Therefore, in FIG. 8, those having the same structure and function as those of the super finishing grinding apparatus 1 are given the same reference numerals as those in the super finishing grinding apparatus 1 and description thereof is omitted.

The super finishing grinding device 1C includes a link mechanism unit 3C, a link driving unit 2, four grindstone holding devices 4C, 4C, 4C, 4C, a driving device 5, a control device, and the like.
In the link mechanism portion 3C of the super finishing grinding device 1C, the grinding surface of the super finishing grindstone 39C held by the grindstone holding device 4C is arranged on the opposite side of the swing link 11b with respect to the virtual plane including the holding shafts 18 and 19. In this manner, the swing link 11 b connected in the middle of the swing arms 12 a and 12 b is brought close to the holding shafts 18 and 19. In the superfinishing grinding apparatus 1C configured as described above, the grinding surface of the superfinishing grindstone 39C located at the tip of the rocking center (axis) O of the grindstone holding apparatus 4C is the moving direction of the nut 212, that is, the rocking link 11a. , 11b move (vibrate) in a direction opposite to the moving direction. The superfinishing grindstone 39C held by the grindstone holding device 4C has a ground surface that is a curved surface that is convex at the center compared to both ends in the width direction. The superfinishing grinding apparatus 1C is used for grinding the surface of a drum-shaped rotating body (work W) having a recessed axial central portion on the peripheral surface as shown in FIG.

Except for the above, the superfinishing grinding apparatus 1C has the same structure and operation as the superfinishing grinding apparatus 1 described above. In FIG. 9, those having the same structure and operation as those of the superfinishing grinding apparatus 1 are given the same reference numerals as those in the superfinishing grinding apparatus 1, and description thereof is omitted.
FIG. 10 is a diagram showing the relationship between the irregularly shaped workpiece W and the superfinishing grindstones 39 and 39C.
The super finishing grinding apparatuses 1 and 1B perform super finishing of the workpiece Wa shown in FIG. 10 (a) in which the cross-sectional shape including the axis is not point-symmetric and the circumferential surface is curved convexly. This can be done by changing or changing the control constant. The superfinishing of the workpiece Wa is performed when the center of vibration of the superfinishing grindstone 39 (center of oscillation of the grindstone holding device 4) OH is not zero, and the workpiece Wa held by the workpiece rotating roll is not zero. The inclination angle −α (α> 0) of the surface (from the vertical surface) including the center of the generatrix of the peripheral surface in the axial direction and the rocking center (axis) O of the grindstone holding device 4 is employed. The controller calculates the value of the rotation angle of the oscillation center in the master servo motor 41 from the input tilt angle -α, sets the rotation angle to zero at the rotation angle, and inputs the vibration angle θ (θ>). 0), the master servo motor 41 and the slave servo motor 42 are rotated forward and backward.

  The superfinishing grinding apparatus 1C changes or controls the control program of the controller for superfinishing of the workpiece Wb shown in FIG. 10B whose cross-sectional shape including the axis is not point-symmetric and whose peripheral surface is concavely curved. This can be done by changing the constant. At this time, the tilt angle from the vertical plane of the center of vibration of the superfinishing grindstone 39 in the superfinishing grinding apparatus 1C (center of rocking of the grindstone holding apparatus 4) OH is the axis of the workpiece Wb held by the workpiece rotating roll. The inclination angle α (α> 0) of the surface including the center of the generatrix of the peripheral surface in the direction and the rocking center (axis) O of the grindstone holding device 4 is employed. The control of the controller based on the vibration angle θ at the time of superfinishing the workpiece Wb is the same as that of the workpiece Wa shown in FIG.

FIG. 11 is a cross-sectional plan view of a superfinishing grinding apparatus 1D having another link drive unit 2D, and FIG. 12 is a view taken along line DD in FIG. FIG. 12A is a diagram when the grindstone holding device 4 is at the origin position, and FIG. 12B is a diagram when the grindstone holding device 4 is swung.
The link driving unit 2D includes a ball screw 21, a nut support member 22D, a connecting pin 55D, guide rails 24 and 24, and the like. The basic configuration of the ball screw 21 and the guide rails 24 and 24 is the same as that in the link drive unit 2 of the superfinishing grinding apparatus 1.

  The nut support member 22D has a generally U-shaped cross section, and a nut 212 is fixed to the concave portion, and a rail guide groove that guides the guide rail 24 on both sides of the concave portion. It is the same as the nut support member 22 of the link drive unit 2 in that The nut support member 22D is integrally formed (fixed) with a connecting pin 55D that protrudes in the horizontal direction and is formed in a rod shape and has a circular cross section. The connecting pin 55D has a flange section 551D having a circular cross section with a larger diameter than the other part at the protruding end.

  The super finishing grinding device 1D is provided with a connecting pin moving hole 122D penetrating through one swinging arm 12b in correspondence with the connecting pin 55D of the link driving unit 2D. The connection pin moving hole 122D has an oval cross section in which a circle having a diameter slightly larger than the diameter of the connection pin 55D excluding the flange portion 551D is divided into two and separated slightly. The connecting pin moving hole 122D is disposed between the swing shafts 15 and 17 that connect the two swing links 11a and 11b with the longitudinal direction of the opening shape thereof aligned with the swing arm 12b.

  In the link driving unit 2D, the connecting pin 55D passes through the connecting pin moving hole 122D, and the flange portion 551D is connected to the swing pin 12D on the opposite side of the nut support member 22D from the connecting pin moving hole 122D. By preventing disconnection, the swing arm 12b is swingably connected. The reason why the connecting pin moving hole 122D is formed into the oval shape is considered so that the linear movement of the connecting pin 55D is not hindered by the connecting pin moving hole 122D that moves on the arc around the holding shaft 19. It is a thing.

  In the superfinishing grinding apparatus 1D, the nut 212 in the link driving unit 2D is positioned in the immediate vicinity of one swing arm 12b. The super finishing grinding device 1D makes the controller memorize that the origin position of the nut 212 is when the inclination angle of the grindstone holding device 4 is zero, so that the super finishing grinding device 1 is super at an arbitrary angle ± θ. The finishing grindstone 39 can be vibrated. Further, the control of the vibration speed of the superfinishing grindstone 39 can be performed in the same manner as the superfinishing grinding apparatus 1.

The superfinishing grinding apparatus 1D may integrate the connecting pin 55D with one swinging arm 12 and pass the connecting pin moving hole 122D through the nut support member 22D.
The configuration other than the above in superfinishing grinding apparatus 1D is the same as that in superfinishing grinding apparatus 1, and the description thereof is omitted.
In the super finishing grinding devices 1, 1B, 1C, any one of the nut 212 and the connecting portion of the swing arm 12b and the connecting rod 23 may be fixed so as not to swing. In this case, the connecting portion on the non-fixed side is formed so that the connecting rod 23 can move to the side opposite to the holding shaft 19 (swing center O) of the swing arm 12b.

The super finishing grinding devices 1, 1B, 1C, and 1D increase the rigidity of the link mechanism portions 3 and 3C, for example, in super finishing of the surface of the spherical roller W whose cross-sectional shape before super finishing is not a perfect circle. In addition to smoothing, the cross-sectional shape can be corrected to a perfect circle.
In the super finishing grinding apparatuses 1, 1 </ b> B, 1 </ b> C, 1 </ b> D, the guide rails 24, 24 and the rail guide grooves 222, 222 are provided even if the guide rails are fixed to the nut support members 22, 22 and the rail guide grooves are provided in the cover 31. Has the same effect as. Moreover, even if these are not one pair each but one each, the improvement of the operation precision and durability of the ball screw 21 can be expected.

In the case of using two servo motors, this processing is performed by using either one of the relative rotation angle zero and the encoder output as a reference, and causing the other to perform the same operation as the reference servo motor.
In addition, each structure or overall structure, shape, size, number, material, etc. of the super finishing grinding apparatuses 1, 1B, 1C, 1D and super finishing grinding apparatuses 1, 1B, 1C, 1D are in accordance with the spirit of the present invention. Can be changed as appropriate.

  The present invention can be used in a super finishing grinding apparatus capable of performing a process for increasing the smoothness of the surface of a spherical roller used in, for example, a spherical roller bearing.

1, 1B, 1C, 1D Super finishing grinding device 4, 4B Grinding wheel holding device 11a, 11b Swing link 12a, 12b Swing arm 14-17 Swing shaft (of link drive unit) 21 Ball screw 22, 22D Nut support material (Component integrated with nut)
23 Connecting rod (connecting means)
24 Guide rail 31 Cover 41 Servo motor (master servo motor)
42 Servo motor (slave servo motor)
55D connecting pin (connecting means)
122D connecting pin moving hole (connecting means)
211 Screw shaft 212 Nut 222 Rail guide grooves 352, 353 Oscillating shaft (of the grindstone holding device)

Claims (5)

The grindstone holding device is rocked by a parallel link in which two rocking links and two rocking arms are connected by four rocking shafts, and two rocking shafts arranged in parallel with the rocking shaft of the rocking arm. A super finishing grinder connected movably,
Servo motor as drive source,
A ball screw constituted by a screw shaft and a nut and rotated by the servo motor;
Superfinishing grinding apparatus, comprising: coupling means for non-fixingly coupling the swing arm to the nut. The connecting means includes a connecting rod having one end connected to the nut and the other end connected to the swing arm.
The superfinishing grinding apparatus according to claim 1. The connecting means includes
A connecting pin moving hole which is a hole penetrating either one of the nut and the swing arm;
The super-finishing according to claim 1, further comprising: a rod-shaped coupling pin that is integrated with one of the nut and the swing arm and is fitted into the coupling pin moving hole so that the nut can be linearly moved. Grinding equipment. The super finishing grinding apparatus according to any one of claims 1 to 3, wherein the servo motor is connected to both ends of the screw shaft one by one. A cover for separating the ball screw and the grindstone holding device between both ends of the screw shaft;
The cover is provided with either one of a bar-shaped guide rail that extends parallel to the screw shaft and a rail guide groove that can be slid into the guide rail.
The superfinishing grinding apparatus according to any one of claims 1 to 4, wherein either the guide rail or the rail guide groove is provided on the nut or a member integrated with the nut.