JP2011224677A - Workpiece peripheral surface grinding machine and workpiece peripheral surface grinding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost grinding technology capable of grinding a peripheral surface of a workpiece with certain working accuracy in a short period of time without deforming the workpiece.SOLUTION: A workpiece peripheral surface grinding machine includes: a pair of grindstones (first and second grindstones 6, 8), rotatably formed centering on a single rotary shaft R1 for performing a grinding process on a peripheral surface of a workpiece (inner periphery 2 m of outer ring 2); and a rotation control mechanism for relatively moving both the grindstones closer to or apart from each other along the rotary shaft and rotating the respective grindstones simultaneously where the grinding process is performed on a peripheral surface of the workpiece in a rotated state by bringing a pair of rotated grindstones into contact with the peripheral surface while moving the grindstones closer to or apart from each other along the direction traversing the peripheral surface of the workpiece.

Description

  The present invention relates to a grinding technique for a peripheral surface of a workpiece (for example, each raceway surface formed in a double row on the peripheral surface of an outer inner ring).

  Conventionally, various grinding techniques for processing a peripheral surface of a workpiece with a grindstone (for example, rough grinding, intermediate finish grinding, finish grinding, etc.) into a desired surface shape are known (for example, patents). Reference 1). As an example, FIG. 5 assumes a circular outer ring 2 that is hollow as a workpiece, and a grinding machine for grinding the inner circumferential surface 2m (circumferential surface) of the outer ring 2 (workpiece) with a grindstone. It is shown.

  The outer ring 2 shown in FIG. 5 has an annular inner ring (not shown) opposed to the inner diameter side thereof, and a plurality of rolling elements (not shown) are incorporated in a double row between the outer and inner rings, for example, an automobile or the like. Configuration to realize a bearing unit that rotatably supports a component on the outboard (wheel) side (for example, a disc wheel) on a component (for example, a knuckle (suspension device)) on the inboard (vehicle body) side It is. A fixing flange 2 a for fixing the outer ring 2 to a knuckle (suspension device) is integrally formed on the outer peripheral surface 2 r of the outer ring 2.

  In the outer ring 2, first and second raceway surfaces (grooves) 2 t and 2 s for rolling a plurality of rolling elements incorporated in a double row in the bearing unit are formed on the inner peripheral surface 2 m. . The first raceway surface 2t is formed by continuously recessing an inner circumferential surface 2m near one side (inboard side) of the outer ring 2 in an arc shape along the circumferential direction. The surface 2s is formed by continuously recessing an inner circumferential surface 2m near the other side (outboard side) of the outer ring 2 in an arc shape along the circumferential direction.

  In addition, the outer ring 2 has an annular first raised up along the first raceway surface 2t on an inner peripheral surface 2m extending between the first raceway surface 2t and the second raceway surface 2s. And a ring-shaped second shoulder Ks raised along the second raceway surface 2s. The first and second cylindrical surfaces that are continuous in a cylindrical shape along the circumferential direction are provided on the inner peripheral surface 2m on one side (inboard side) and the other side (outboard side) of the outer ring 2, respectively. Ft and Fs are formed. Sealing members (not shown) for sealing the bearing inner space defined between the outer ring 2 and the inner ring from the outside of the bearing can be attached to the cylindrical surfaces Ft and Fs.

  Here, the grinding machine for grinding the inner circumferential surface 2 m of the outer ring 2 includes one spindle 4 and an annular grindstone structure fixed to the tip of the spindle 4. In this case, by controlling the rotation of the spindle 4, the grindstone structure can be rotated in a predetermined direction around the rotation axis R1 of the spindle 4. The rotation axis R1 of the spindle 4 is set parallel to the central axis R2 of the outer ring 2, and the central axis R2 of the outer ring 2 is the bearing unit when the outer ring 2 and the inner ring are relatively rotated. It is defined as an axis that coincides with the rotation axis (center axis).

  The grindstone structure is set to a size (outer diameter dimension) that can be inserted into the inner diameter side of the hollow annular outer ring 2, and the inner circumferential surface 2 m on one side (inboard side) of the outer ring 2 is ground. And an annular second grindstone 8 that grinds the inner peripheral surface 2m on the other side (outboard side) of the outer ring 2. The first grindstone 6 and the second grindstone 8 are connected to each other via a connecting member 10 and are configured to be coaxial (same center) with the rotation axis R1 of the spindle 4.

  The first grindstone 6 includes an annular first raceway surface (groove) grinding portion 60 for grinding the first raceway surface (groove) 2 t of the outer ring 2, and a first cylindrical surface Ft of the outer ring 2. An annular first cylindrical surface grinding portion 62 that performs grinding processing is provided. The second grindstone 8 includes an annular second raceway surface (groove) grinding portion 80 for grinding the second raceway surface (groove) 2 s of the outer ring 2, and a second cylindrical surface Fs of the outer ring 2. An annular second cylindrical surface grinding portion 82 for performing a grinding process is provided.

  First and second orbital grinding surfaces 60s and 80s each having a substantially arc shape continuous in the circumferential direction are formed on the outer diameter sides of the first and second orbital surface grinding portions 60 and 80, respectively. Each orbital grinding surface 60s, 80s is pre-truded (abrasive surface forming process) and dressing (abrasive surface sharpening process) according to the content of the grinding process (for example, rough grinding, intermediate finish grinding, finish grinding, etc.). Is given. The first and second cylindrical grinding surfaces 62s and 82s are formed on the outer diameter sides of the first and second cylindrical grinding units 62 and 82, respectively, and have substantially cylindrical shapes continuous along the circumferential direction. Each of the cylindrical grinding surfaces 62s and 82s is preliminarily subjected to truing (abrasive surface forming process) and dressing (abrasive surface sharpening) according to the content of the grinding process (for example, rough grinding, intermediate finish grinding, finish grinding, etc.). Processing). Also, truing (abrasive surface forming process) and dressing (abrasive surface sharpening process) may be performed simultaneously by a diamond wheel.

  The distance between the first raceway surface grinding portion 60 and the second raceway surface grinding portion 80 (that is, between the first and second raceway surface grinding portions 60, 80 in the direction along the rotation axis R1 of the spindle 4). The distance is the distance between the first raceway surface 2t of the outer ring 2 and the second raceway surface 2s (that is, the first and second raceway surfaces 2t, 2s in the direction along the central axis R2 of the outer ring 2). The distance is set to match. Note that the distance between the first cylindrical surface grinding part 62 and the second cylindrical surface grinding part 82 (that is, the first cylindrical surface grinding part 62, 82 in the direction along the rotation axis R1 of the spindle 4). The mutual distance is the distance between the first cylindrical surface Ft of the outer ring 2 and the second cylindrical surface Fs (that is, the first and second cylindrical surfaces Ft, Fs in the direction along the central axis R2 of the outer ring 2). (Distance between each other).

  The outer diameter dimensions of the first raceway surface grinding unit 60 and the second raceway surface grinding unit 80 are the first and second of the raceway surface grinding units 60 and 80 when the inner circumferential surface 2m of the outer ring 2 is ground. The two orbital grinding surfaces 60s and 80s are set so as to be in contact with the first and second orbital surfaces 2t and 2s at the same time. The outer diameter dimensions of the first cylindrical surface grinding part 62 and the second cylindrical surface grinding part 82 are the first outer diameters of the cylindrical surface grinding parts 62 and 82 when the inner circumferential surface 2m of the outer ring 2 is ground. The second cylindrical grinding surfaces 62s and 82s are set so as to simultaneously contact the first and second cylindrical surfaces Ft and Fs.

  When grinding is performed on the inner peripheral surface 2m of the outer ring 2 by such a grinding machine, first, the outer ring 2 processed into a rough shape by another machine tool is set on the rotation holding mechanism. As an example of the rotation holding mechanism, the rotation holding mechanism includes an adsorption plate 12 (for example, a backing plate) that adsorbs the circumferential end surface of the outer ring 2 (for example, the circumferential end surface 2p on the other side (outboard side)) by magnetic action. And a holding member 14 (for example, a pair of shoes) that holds the outer peripheral surface 2r of the outer ring 2. The pair of shoes 14 has an opening angle of approximately 90 degrees and abuts against the lateral portion and the lower portion of the outer ring 2 (in the drawing, only the configuration in contact with the outer peripheral surface 2r of the outer ring 2 is shown). The position is a position moved downward from the rotation center of the suction plate 12 substantially parallel to a straight line connecting the two contact points with the shoe 14. As a result, the outer ring 2 is rotated while its peripheral end surface 2p is attracted by the magnetic force of the suction plate 12, thereby giving a holding force between the pair of shoes 14, and the outer peripheral surface 2r is held by the shoes 14. Is done.

  Next, the spindle 4 is moved in the direction along the rotation axis R1, and the grindstone structure fixed at the tip of the spindle 4 and rotating at high speed is moved from one side (inboard side) of the outer ring 2 to the outer ring 2. The first and second raceway surface grinding portions 60 and 80 are opposed (facing directly) to the first and second raceway surfaces 2t and 2s of the outer ring 2. Along with this, the first and second cylindrical surface grinding portions 62 and 82 of the grindstone structure are opposed (facing) to the first and second cylindrical surfaces Ft and Fs of the outer ring 2.

  From this state, the rotation holding mechanism is translated along the direction (radial direction) orthogonal to the central axis R2 of the outer ring 2 (in another way, the grindstone structure is directed toward the inner peripheral surface 2m of the outer ring 2). The first and second raceway surface grinding portions 60 and 80 (first and second) of the grindstone structure are brought into contact with each other by bringing the outer ring 2 and the grindstone structure into contact with each other. Are brought into contact with the first and second raceway surfaces 2t and 2s of the outer ring 2. Accordingly, the first and second cylindrical surface grinding portions 62 and 82 (first and second cylindrical grinding surfaces 62 s and 82 s) of the grindstone structure are used as the first and second cylindrical surfaces Ft of the outer ring 2. , Fs.

  At this time, the first and second raceway grinding surfaces 60s and 80s and the first and second raceway surfaces 2t and 2s are in line contact with each other. Also, the first and second cylindrical grinding surfaces 62s and 82s and the first and second cylindrical surfaces Ft and Fs are in line contact with each other.

  Since the outer ring 2 and the grindstone structure are rotating relative to each other, the first and second raceway surfaces 2t and 2s of the outer ring 2 and the first and second cylindrical surfaces Ft and Fs are ground (for example, , Rough grinding, intermediate finish grinding, finish grinding, etc.) are performed, and the inner peripheral surface 2m of the outer ring 2 is processed into a predetermined surface shape.

  By the way, in the bearing unit to which the outer ring 2 is applied, high turning with respect to various loads (for example, radial load, axial load, moment load, etc.) acting at the time of turning of the vehicle in recent years as the performance of automobiles and the like is improved. A load is required. In order to meet such a requirement, the rising amount of the first and second shoulder portions Kt, Ks raised along the first and second raceway surfaces 2t, 2s on the inner peripheral surface 2m of the outer ring 2 ( That is, the height dimension in the direction (radial direction) orthogonal to the central axis R2 of the outer ring 2 is set large.

  Here, when the rising amounts of the first and second shoulder portions Kt, Ks are increased, the inclinations of the tangents T1, T2 defined on the raceway surfaces 2t, 2s near the shoulder portions Kt, Ks are accordingly accompanied. The corner becomes smaller. In this case, these inclination angles are a plane (radial plane) orthogonal to the central axis R2 of the outer ring 2, and tangents T1, T2 contacting the first and second track surfaces 2t, 2s near the shoulders Kt, Ks. Is defined as the angle formed by

  In the grinding process described above, the outer ring 2 and the grindstone structure are relatively translated along a direction (radial direction) orthogonal to the central axis R2 of the outer ring 2 to bring the outer ring 2 and the grindstone structure into contact with each other. ing. In this case, the cutting direction H of the grindstone structure (first and second grindstones 6 and 8) with respect to the inner peripheral surface 2m of the outer ring 2, that is, the first and second with respect to the first and second raceway surfaces 2t and 2s. The incision direction H of the raceway surface grinding portions 60, 80 (first and second raceway grinding surfaces 60s, 80s) is parallel to the radial direction. At this time, the incision direction H is a tolerance angle (the tangent line T1, T2) with the inclination angle of the tangent line T1, T2 defined on each of the track surfaces 2t, 2s near the first and second shoulder portions Kt, Ks. The angle formed by T2 and the cutting direction H) becomes smaller.

  Then, in the above-described grinding process, the first and second raceway surface grinding portions 60 and 80 (first and second raceway grinding surfaces 60s and 80s) are radially directed toward the inner peripheral surface 2m of the outer ring 2. The first and second raceway surface grinding portions 60 and 80 (first and second raceway grinding surfaces 60s and 80s) are moved to the first and second raceway surfaces 2t. , 2 s before contacting the shoulder Kt, Ks first.

  At this time, since the grinding process cannot be performed on the first and second raceway surfaces 2t and 2s unless the grinding process in the vicinity of the shoulders Kt and Ks is finished, the grinding process in the vicinity of the shoulders Kt and Ks is performed. If the time required is prolonged, the time (cycle time) until the first and second raceway surfaces 2t, 2s and the first and second cylindrical surfaces Ft, Fs are ground correspondingly. It will grow.

  Further, the cutting direction H of the first and second raceway surface grinding portions 60, 80 and the tangent lines T1, T2 defined by the raceway surfaces 2t, 2s near the first and second shoulder portions Kt, Ks described above. When the tolerance angle with respect to the inclination angle becomes smaller, the first and second raceway surface grinding portions 60, 80 are forced to straddle the first and second shoulder portions Kt, Ks in the first and second states. Are cut into the raceway surfaces 2t and 2s. At that time, reaction forces from the first and second shoulder portions Kt and Ks act on the first and second raceway surface grinding portions 60 and 80, and the both raceway surface grinding portions 60 and 80 are separated from each other. The pressing force in the direction to be activated will work.

  In this case, depending on the magnitude of the above-described pressing force, for example, the first and second raceway surface grinding portions 60 and 80 (grinding stone structures) are likely to suffer from problems such as cracking, grinding burn, and return. In order to avoid this, it is necessary to reduce (lower) the cutting speed of the grindstone structure (the first and second raceway surface grinding portions 60, 80) with respect to the inner peripheral surface 2m of the outer ring 2. As a result, the time (cycle time) until the first and second raceway surfaces 2t, 2s and the first and second cylindrical surfaces Ft, Fs are ground is increased by the amount by which the cutting speed is reduced. .

  Furthermore, as described above, the time (cycle time) until the inner peripheral surface 2m of the outer ring 2, that is, the first and second raceway surfaces 2t, 2s and the first and second cylindrical surfaces Ft, Fs are ground. When the length is increased, it takes time and effort to complete the grinding process, and as a result, the cost required for the grinding process increases.

  In the above grinding process, when the grindstone structure is cut into the inner peripheral surface 2 m of the outer ring 2, a relatively large cutting force acts on the outer ring 2, so that a rotation holding mechanism for the peripheral end surface 2 p of the outer ring 2 ( The suction force of the suction plate 12) needs to be set large. For this reason, there is a possibility that friction with the suction plate 12 and the shoe (holding member) 14 is increased, scratches or wear may occur at the contact points described above, or the outer ring 2 may be deformed to cause a reduction in processing accuracy.

  Further, when the grindstone structure is cut into the inner peripheral surface 2m of the outer ring 2, depending on the magnitude of the cutting force acting on the outer ring 2, for example, the outer ring 2 as a workpiece is deformed, or, for example, the outer ring is There is also a possibility that the rotation holding mechanism to hold may be damaged. Here, for example, when the grinding process is performed in a state where the outer ring 2 is deformed, it becomes difficult to process the inner peripheral surface 2m of the outer ring 2 into a desired surface shape, and thus the processing accuracy is kept constant. There is a risk that it will be impossible.

JP 2000-246605 A

  The present invention has been made in order to solve such a problem, and the object thereof is a low cost capable of grinding the peripheral surface of the workpiece with a constant processing accuracy in a short time without deforming the workpiece. It is to provide grinding processing technology.

In order to achieve such an object, the workpiece peripheral surface grinding machine of the present invention is configured to be rotatable around a single rotation axis, and a pair of grindstones that grind the peripheral surface of the workpiece, A rotation control mechanism that rotates the grindstones relative to each other in the direction of approaching or separating from each other along the rotation axis and simultaneously rotating the grindstones, and rotating the pair of grindstones in a state where the workpiece is rotated, A grinding process is performed on the peripheral surface of the workpiece by bringing the peripheral surface into contact with or spaced apart from each other along a direction crossing the peripheral surface of the workpiece.
In the present invention, a pair of grooves continuously recessed in an arc shape along the circumferential direction is formed on the peripheral surface of the workpiece, and the pair of grindstones each have a groove grinding portion that performs a grinding process on the grooves. In a state where the workpiece is rotated, the pair of rotated grindstones are brought into contact with the circumferential surface while approaching or separating from each other along a direction traversing the circumferential surface of the workpiece. When the grinding process is performed on the peripheral surface, each groove grinding portion is cut toward the center direction of each groove or the contact angle direction intersecting each groove.
In the present invention, the work is held by a rotation holding mechanism that rotates the work around the rotation axis and moves along the direction orthogonal to the rotation axis. The work rotated by the rotation holding mechanism is By moving along a direction orthogonal to the rotation axis and bringing the pair of grindstones rotated by the rotation control mechanism into contact with the circumferential surface while approaching or separating from each other along the direction crossing the circumferential surface of the workpiece, Grind the workpiece surface.
In the present invention, the work is a bearing ring of bearings arranged so as to be relatively rotatable via rolling elements incorporated in a double row, and the rolling elements roll on the circumferential surfaces facing each other. Grooves are continuously formed in a circular arc shape along the circumferential direction and formed in double rows.
Further, the present invention is a work peripheral surface grinding method using the above-described work peripheral surface grinding machine, and in a state where the work is rotated, a direction in which the pair of grindstones rotated across the peripheral surface of the work is crossed. The peripheral surface of the work is ground by being brought into contact with or spaced apart from each other along the surface.

  According to the present invention, the magnetic force of the suction plate is reduced by lowering the grinding resistance, the friction with the suction plate and the shoe is reduced, and the deformation of the work due to the grinding resistance itself is reduced. Therefore, it is possible to realize a low-cost grinding technique that can grind the peripheral surface of the workpiece with a constant processing accuracy in a short time.

Sectional drawing which shows schematically the structure of the workpiece | work peripheral surface grinding machine which concerns on the 1st Embodiment of this invention. Sectional drawing which shows schematically the structure of the workpiece peripheral surface grinding machine which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows schematically the structure of the workpiece | work peripheral surface grinding machine which concerns on the modification of 2nd Embodiment shown by FIG. The figure which shows the cutting direction of the grindstone with respect to each track surface (groove). Sectional drawing which shows schematically the structure of the conventional workpiece peripheral surface grinding machine.

Hereinafter, the workpiece peripheral surface grinding technique according to the first embodiment of the present invention will be described with reference to FIG.
In this embodiment, it is possible to assume a bearing ring (outer ring 2, inner ring not shown) of a bearing that is opposed and arranged to be relatively rotatable via rolling elements (not shown) incorporated in double rows. There is a groove (track surface) for rolling elements rolling on the circumferential surface (circumferential surface 2 m of the outer ring 2, outer peripheral surface of the inner ring (not shown)) facing each other. It is formed in a double row by being continuously depressed in the shape.

  In this embodiment, an outer ring 2 (FIG. 5), which is one configuration for realizing the above-described bearing unit, is applied as an example of a workpiece. A pair of grooves (first and second raceway surfaces 2t, 2s) that are continuously recessed in an arc shape along the circumferential direction are formed on the inner peripheral surface 2m of the outer ring 2. In addition, about the structure same as the outer ring | wheel 2 (FIG. 5) mentioned above, the code | symbol same as the reference mark attached | subjected to the structure is attached | subjected to FIG. 1, and the description is abbreviate | omitted.

  In addition, the work surface grinding machine including the above-described rotation holding mechanism (the suction plate 12 and the holding member 14) is applied to the work surface grinding technique according to the present embodiment. The suction plate 12 is attached to the housing 20 (for example, the main body of the rotation holding mechanism) via one back combination (DB type) bearing configured by bringing the back surfaces of the two angular ball bearings 16 and 18 into contact with each other. The holding member 14 is rotatably supported.

  The outer ring 2 as a work is set in the above-described rotation holding mechanism. In the set state, the outer peripheral surface 2r is held while the peripheral end surface 2p is adsorbed by the magnetic action of the adsorption plate 12. It is held by the member 14. The rotation holding mechanism can be moved in a desired direction while rotating the rotation holding mechanism by a control device (not shown).

  In this case, in a state where the outer ring 2 is set (held) in the rotation holding mechanism, the rotation holding mechanism (suction plate 12) is rotated by a control device (not shown), whereby the outer ring 2 is moved to its central axis R2 (this embodiment). In the embodiment, it can be rotated around a rotation axis), and the rotation holding mechanism is moved by a control device (not shown), whereby the held outer ring 2 is moved in directions Y1 and Y2 orthogonal to the rotation axis R2. It can be moved along with a predetermined timing (movement speed, movement amount).

  Furthermore, the workpiece peripheral surface grinding machine of the present embodiment is configured to be rotatable about a single rotation axis R1, and a pair of grindstones 6 and 8 for grinding the inner peripheral surface 2m of the outer ring 2 are provided. There is provided a rotation control mechanism for rotating the grindstones 6 and 8 at the same time while relatively moving the grindstones 6 and 8 toward or away from each other along the rotation axis R1.

  In the present embodiment, the first grindstone 6 and the second grindstone 8 (FIG. 5) which are the structures of the grindstone structure described above are applied as the pair of grindstones 6 and 8, respectively. The first and second grindstones 6 and 8 have groove grinding portions (first raceway surface grinding portion 60 and second raceway grinding portion 60) for grinding the first and second raceway surfaces 2t and 2s of the outer ring 2, respectively. A raceway grinding unit 80) is provided. In addition, about the structure same as said 1st and 2nd grindstone 6,8 (FIG. 5) mentioned above, the description is attached by attaching | subjecting the code | symbol same as the reference mark attached | subjected to the structure to FIG. Omitted.

  The rotation control mechanism rotates the first grindstone 6 about the rotation axis R1 and also moves the first grindstone 6 along the rotation axis R1 and the second grindstone. And a second rotation control mechanism for rotating the second grindstone 8 along the rotation axis R1.

  The first rotation control mechanism includes a first rotating device that rotates the first grindstone 6 about the rotation axis R1, and a first slide table that moves the first grindstone 6 along the rotation axis R1. 22 and the first rotating device is constructed on the first slide table 22. The first slide table 22 can be moved along the rotation axis R1 in the directions of the arrows X1 and X2 at a predetermined timing (moving speed, moving amount) by a movement control device (not shown). Yes.

  The first rotating device includes one first spindle 4a extending along the rotation axis R1, and a first bearing mechanism that supports the first spindle 4a so as to be rotatable about the rotation axis R1. And a first motor 24 for rotating the first spindle 4a. The first grindstone 6 described above is fixed to the distal end of the first spindle 4a, and the first motor 24 is connected to the proximal end of the first spindle 4a.

  A motor pulley 26 is fixed to the rotating shaft 24a of the first motor 24, while a spindle pulley 28 is fixed to the base end of the first spindle 4a. One endless belt 30 is stretched over 28. In this case, the rotational motion output to the rotary shaft 24a of the first motor 24 is transmitted from the motor pulley 26 to the spindle pulley 28 via the endless belt 30, so that the first spindle 4a is moved to the first spindle 4a. It can be rotated around the rotation axis R1.

  The first bearing mechanism includes a housing 32 provided on the first slide table 22, and a plurality of bearings 34, 36, and 38 incorporated between the housing 32 and the first spindle 4a. Yes. As an example of the plurality of bearings 34, 36, 38, here, one back combination (DB type) bearing configured by bringing the back surfaces of the two angular ball bearings 34, 36 into contact with each other, and one Assume a roller bearing 38.

  According to such a first rotation control mechanism, the first grindstone 6 is rotated by the first rotation device, and the first slide table 22 is moved in the directions of the arrows X1 and X2 by the movement control device (not shown). By moving, the first grindstone 6 can be rotated about the rotation axis R1 and can be moved along the rotation axis R1 at a predetermined timing (movement speed, movement amount).

  The second rotation control mechanism includes a second rotating device that rotates the second grindstone 8 around the rotation axis R1, and a second slide table that moves the second grindstone 8 along the rotation axis R1. 40, and the second rotating device is constructed on the second slide table 40. The second slide table 40 can be moved at a predetermined timing (moving speed, moving amount) in the directions of the arrows X1 and X2 along the rotation axis R1 by a movement control device (not shown). Yes.

  The second rotating device includes one second spindle 4b extending along the rotation axis R1, and a second bearing mechanism that supports the second spindle 4b so as to be rotatable about the rotation axis R1. And a second motor 42 for rotating the second spindle 4b. The second grindstone 8 described above is fixed to the tip of the second spindle 4b, and the second motor 42 is connected to the base end of the second spindle 4b.

  A motor pulley 44 is fixed to the rotating shaft 42a of the second motor 42, while a spindle pulley 46 is fixed to the base end of the second spindle 4b. One endless belt 48 is stretched around 46. In this case, the rotational motion output to the rotating shaft 42a of the second motor 42 is transmitted from the motor pulley 44 to the spindle pulley 46 via the endless belt 48, so that the second spindle 4b is moved to the second spindle 4b. It can be rotated around the rotation axis R1.

  The second bearing mechanism includes a housing 50 provided on the second slide table 40, and a plurality of bearings 52, 54, 56 incorporated between the housing 50 and the second spindle 4b. Yes. As an example of the plurality of bearings 52, 54, 56, here, one back combination (DB type) bearing configured by bringing the back surfaces of the two angular ball bearings 52, 54 into contact with each other, and one Assume a roller bearing 56.

  According to such a second rotation control mechanism, the second grindstone 8 is rotated by the second rotation device, and the second slide table 40 is moved in the directions of the arrows X1 and X2 by the movement control device (not shown). By moving, the second grindstone 8 can be rotated about the rotation axis R1 and moved along the rotation axis R1 at a predetermined timing (movement speed, movement amount).

Next, a work peripheral surface grinding method using the work peripheral surface grinding machine described above will be described.
In the workpiece peripheral surface grinding method of the present embodiment, the workpiece (outer ring 2) rotated by the rotation holding mechanism described above is moved along the directions Y1 and Y2 orthogonal to the rotation axis R2, and the first and first described above. The first and second grindstones 6 and 8 rotated by the rotation control mechanism 2 are arranged along the direction crossing the inner peripheral surface 2m of the outer ring 2 (that is, in the directions of the arrows X1 and X2 along the rotation axis R1). ) The inner circumferential surface 2m of the outer ring 2 is ground by contacting the inner circumferential surface 2m while approaching or separating from each other.

  Specifically, first, in a state where the outer ring 2 is set (held) on the rotation holding mechanism, the rotation holding mechanism is moved to the arrows Y1, Y2, and the first and second grindstones 6, 8 are moved to the outer ring 2. The outer ring 2 is positioned at a position where it can be inserted into the inner diameter side.

  Next, the first slide table 22 is moved in the direction of the arrow X1, and the first grindstone 6 is inserted from one side (inboard side) of the outer ring 2 to the inner diameter side of the outer ring 2, and in synchronization therewith. Then, the second slide table 40 is moved in the direction of the arrow X1, and the second grindstone 8 is passed from the other side (outboard side) of the outer ring 2 through the rotation holding mechanism (hollow suction plate 12) to the outer ring 2. Insert on the inside diameter side.

  The insertion amount (insertion position) of the first and second grindstones 6 and 8 at this time is determined based on the first and second grindstones 6 and 8 (specifically, the first and second raceway surfaces). The grinding parts 60, 80) are set so that they can be cut into the first and second raceway surfaces 2t, 2s of the outer ring 2 at the same timing (moving speed, moving amount). As a result, the first and second grindstones 6 and 8 (specifically, the first and second cylindrical surface grinding portions 62 and 82) are also applied to the first and second cylindrical surfaces Ft and Fs of the outer ring 2. On the other hand, they are set so that they can be cut at the same timing (moving speed, moving amount).

  Subsequently, by rotating the rotation holding mechanism, while rotating the outer ring 2 around the rotation axis R2, at the same time, by moving the rotation holding mechanism, the direction Y1 orthogonal to the rotation axis R2 , Y2 (Y1 direction in the drawing). That is, the inner peripheral surface 2 m of the outer ring 2 is brought close to the first and second grindstones 6 and 8.

  At the same time, the first rotating device 6 rotates the first grindstone 6 about its rotation axis R1, and the second rotating device rotates the second grindstone 8 about its rotation axis R1, while The second slide tables 22 and 40 are moved in synchronization with each other in the direction of the arrow X1, and the first and second grindstones 6 and 8 are moved closer to each other along the rotation axis R1.

  Then, the outer ring 2 is further moved in the Y1 direction while being rotated, and the paired grindstones 6 and 8 are moved closer to each other along the direction crossing the inner peripheral surface 2m of the outer ring 2 while the inner peripheral surface is being moved. Contact 2m. Thereby, the grinding process with respect to the inner peripheral surface 2m of the outer ring 2 is performed.

  At that time, the first and second raceway surface grinding portions 60 and 80 (first and second raceway grinding surfaces 60s and 80s) of the first and second grinding wheels 6 and 8 are connected to the first and second raceway grinding surfaces 60s and 80s. It is cut toward the center directions H1, H2 of the second raceway surfaces 2t, 2s or the contact angle directions H1, H2 intersecting the first and second raceway surfaces 2t, 2s. In this case, the cutting directions H1 and H2 of the first and second grindstones 6 and 8 (the first and second raceway surface grinding portions 60 and 80) with respect to the first and second raceway surfaces 2t and 2s are conventionally known. Although parallel to the radial direction (plane) (FIG. 5), in this embodiment, the direction is inclined with respect to the radial direction (plane).

  The center of the first and second raceway surfaces 2t and 2s is the middle of the width dimension of each raceway surface 2t and 2s forming an arc shape (also referred to as “groove width” that defines the rolling region of the rolling element). Defined as a site. The contact angle between the first and second raceway surfaces 2t and 2s is such that a plurality of rolling elements (not shown) are provided between the raceway surfaces 2t and 2s and the raceway surface (not shown) of the inner ring facing them. In a state where a bearing unit is configured by adding a predetermined preload, a radial plane perpendicular to the rotation axis R2 of the outer ring 2 coinciding with the rotation axis (center axis) of the bearing unit and the raceway surfaces 2t, 2s It is defined as the angle formed by the line of action of the resultant force transmitted to each rolling element.

  Here, as an example of the cutting directions H1 and H2, for example, as shown in FIG. 4, when the angle (grinding range) formed by the groove widths of the first and second raceway surfaces 2t and 2s is 100 °, The cutting directions H1 and H2 of the first and second grindstones 6 and 8 (the first and second raceway surface grinding portions 60 and 80) with respect to the first and second raceway surfaces 2t and 2s are radial directions (planes) Ps. It is preferable to set in a direction inclined at an angle of 20 °. Thereby, the grinding speed can be maximized.

  In this case, the cutting directions H1 and H2 are relatively set to the timing (approaching speed) at which the first and second grindstones 6 and 8 approach each other with respect to the timing (moving speed) at which the outer ring 2 is moved in the Y1 direction. The desired angle can be set by speeding up or slowing down relatively. For example, by making the moving speed of the outer ring 2 in the Y1 direction constant and increasing the approach speed of both the grindstones 6 and 8, the inclination angles (cutting angles) of the cutting directions H1 and H2 with respect to the radial direction (plane) Ps are increased. Conversely, by reducing the approach speed of both the grindstones 6 and 8, the inclination angles (cutting angles) of the cutting directions H1 and H2 with respect to the radial direction (plane) Ps can be reduced.

  At this time, according to the cutting directions H1 and H2 of the first and second grindstones 6 and 8 (first and second raceway surface grinding portions 60 and 80) with respect to the first and second raceway surfaces 2t and 2s described above. The first and second cylindrical surface grinding portions 62 and 82 (first and second cylindrical grinding surfaces 62 s and 82 s) of the first and second grinding wheels 6 and 8 are also the first and second cylindrical grinding surfaces 62 s and 82 s of the outer ring 2. Cut toward the two cylindrical surfaces Ft and Fs. Thereby, the grinding treatment (for example, rough grinding, intermediate finish grinding, finish grinding, etc.) is performed on the first and second raceway surfaces 2t, 2s of the outer ring 2 and the first and second cylindrical surfaces Ft, Fs. ) And the inner peripheral surface 2m of the outer ring 2 is processed into a predetermined surface shape.

  As described above, according to the present embodiment, in the grinding process, the first and second grindstones 6 and 8 (first and second raceway surface grinding units 60 for the first and second raceway surfaces 2t and 2s of the outer ring 2 are provided. , 80) incline directions H1, H2 are inclined with respect to the radial direction (plane), and each raceway surface grinding portion 60, 80 (each raceway grinding surface 60s, 80s) is centered on each raceway surface 2t, 2s. Before contacting the first and second raceway surfaces 2t and 2s as in the prior art by cutting toward H1 and H2 or the contact angle directions H1 and H2 intersecting the raceway surfaces 2t and 2s. The first and second grindstones 6 and 8 (first and second raceway grinding units 60 and 80 from the position avoiding the shoulders Kt and Ks without first contacting the shoulders Kt and Ks in the first place. ) Directly in contact with the first and second raceway surfaces 2t and 2s of the outer ring 2, the inner peripheral surface A 2 m grinding process can be performed.

  Thereby, time (cycle time) until it grinds the 1st and 2nd track surfaces 2t and 2s and the 1st and 2nd cylindrical surfaces Ft and Fs can be shortened. As a result, the labor and time required to complete the grinding process are eliminated, and the cost required for the grinding process can be reduced accordingly.

  In the present embodiment, since the two first and second grindstones 6 and 8 are independent, one side (inboard side) and the other side (outboard side) of the outer ring 2 due to variations in the previous process. The machining allowance (grinding allowance) varies, and the grinding process is started earlier by only one groove (one groove of the first raceway surface 2t or the second raceway surface 2s). However, it does not affect the occurrence of axial force (deflection, deformation) or the like on the grindstone located on the opposite side (the grindstone of either the first grindstone 6 or the second grindstone 8).

  Thus, the inner peripheral surface of the outer ring 2 without causing the above-described conventional problems (for example, cracking of the first and second raceway surface grinding portions 60, 80 (grinding stone structure), grinding burn, return, etc.). The cutting speed of the first and second grindstones 6 and 8 (first and second raceway surface grinding portions 60 and 80) with respect to 2 m (first and second raceway surfaces 2t and 2s) can be improved. As a result, the time (cycle time) required for the grinding process can be significantly shortened compared to the conventional case.

  In this case, when the first and second grindstones 6 and 8 are cut into the inner peripheral surface 2m of the outer ring 2, a relatively smaller cutting force is applied to the outer ring 2 than in the prior art. The outer ring 2 can be stably held without unnecessarily increasing the suction force of the rotation holding mechanism (suction plate 12) with respect to 2p. As a result, the outer ring 2 is deformed, or the friction with the suction plate 12 and the shoe (holding member) 14 is increased, so that the above-mentioned contact point is scratched or worn, or the outer ring 2 is deformed to improve the processing accuracy. Generation | occurrence | production of the malfunction which falls can be suppressed, and the inner peripheral surface 2m of the outer ring | wheel 2 can be ground with a fixed process precision, and can be processed into a desired surface shape.

  Furthermore, according to the present embodiment, the first and second slide tables 22 and 40 are moved in the directions of the arrows X1 and X2, and the rotation holding mechanism is moved in the directions of the arrows Y1 and Y2. Therefore, for example, the rotation holding mechanism is fixed and the first and second slide tables 22 and 40 are moved in the directions of the arrows X1 and X2 and in the directions of the arrows Y1 and Y2, so that the work is cheaper than the so-called four-axis control. A circumferential grinder can be realized. If the first and second slide tables 22 and 40 are moved synchronously with one ball screw whose opposite ends are oppositely threaded, control with two axes is possible. Further price reduction can be achieved.

Next, a workpiece peripheral surface grinding technique according to the second embodiment of the present invention will be described with reference to FIG.
The workpiece peripheral surface grinding machine applied to the present embodiment is an improvement of the above-described rotation control mechanism. The rotation control mechanism rotates the first grindstone 6 around the rotation axis R1 and also the first grindstone. The first grindstone 8 is rotated along the rotation axis R1 and the second grindstone 8 is rotated around the rotation axis R1. The second grindstone 8 is rotated along the rotation axis R1. A second rotation control mechanism to be moved and a fast-forward mechanism that fast-forwards the first and second rotation control mechanisms along the rotation axis R1 are provided.

  In the first rotation control mechanism, the first spindle 4a, which is the configuration of the first rotating device, and the first grindstone 6 fixed to the tip of the first spindle 4a are concentrically penetrated along the rotation axis R1. It has a hollow structure. Since other configurations are the same as those of the first embodiment described above, description thereof is omitted.

  In the second rotation control mechanism, the second spindle 4b, which is the configuration of the second rotating device, is inserted into the first spindle 4a coaxially with the rotation axis R1 (same center). The tip of the second spindle 4b extends beyond the first grindstone 6 along the rotation axis R1, and the second grindstone 8 is fixed to the extending end. On the other hand, the base end of the second spindle 4b extends beyond the base end of the first spindle 4a along the rotation axis R1, and the extension end is rotatably supported by the second bearing mechanism. Yes.

  The second rotating device includes a second spindle 4b and a second bearing mechanism. The second motor 42, the pulleys 44 and 46, and the belt 48 applied in the first embodiment described above. (FIG. 1) is not provided. Further, the second bearing mechanism is configured by bringing the back surfaces of the two angular ball bearings 52 and 54 into contact with each other between the housing 50 provided on the second slide table 40 and the second spindle 4b. Only one back combination (DB type) bearing is incorporated. Since other configurations are the same as those of the second embodiment described above, description thereof is omitted.

  In the present embodiment, the first spindle 4a and the second spindle 4b inserted into the first spindle 4a are movable relative to each other along the rotation axis R1, and the rotation axis R1. It is configured so that relative rotation is impossible. As an example of a moving mechanism for realizing such a configuration, a plurality of spline grooves (not shown) extending along the direction of the rotation axis R1 are formed on the opposing surfaces of the first spindle 4a and the second spindle 4b. A ball spline may be configured by forming a plurality of balls (for example, steel balls) facing each other at predetermined intervals along the circumferential direction and incorporating a plurality of balls (for example, steel balls) between the facing spline grooves.

  According to such a configuration, the first and second slide tables 22 and 40 are moved relative to each other in the directions of the arrows X1 and X2 along the rotation axis R1, so that the first spindle 4a and the second spindle 4b Can be moved relative to each other along the rotation axis R1. Thereby, the 1st and 2nd grindstone 6 and 8 can be relatively moved in the direction which mutually approaches or spaces apart along rotation axis R1.

  Further, when the first motor 24 which is the configuration of the first rotating device is rotated, the rotational motion output to the rotating shaft 24a at that time is transferred from the motor pulley 26 via the endless belt 30 to the spindle pulley 28. And the first spindle 4a is rotated about its rotation axis R1. At this time, the first spindle 4a and the second spindle 4b rotate in the same direction, whereby the first and second grindstones 6 and 8 can be simultaneously rotated about the rotation axis R1.

  In addition, the fast-forward mechanism newly applied in the present embodiment is configured so that the first and second slide tables 22 and 40 are moved along the rotation axis R1 in the directions of the arrows X1 and X2 at a predetermined timing (movement speed, movement amount). By moving the relative movement control device and the first and second slide tables 22 and 40 along the rotation axis R1 in the directions of arrows Z1 and Z2 at a predetermined timing (movement speed, movement amount), A fast-forwarding device that moves both the first and second grindstones 6 and 8 along the rotation axis R1 in the directions of arrows Z1 and Z2 at a predetermined timing (moving speed, moving amount) is provided.

  The fast-forwarding device includes a third slide table 90 that can move in the directions of arrows Z1 and Z2 along the rotation axis R1, and an actuator 92 that moves the third slide table 90 in the directions of arrows Z1 and Z2 along the rotation axis R1. And. The movement control device is built on the third slide table 90. The first and second rotation control mechanisms described above are provided on the third slide table 90. Also, in the drawing, the actuator 92 is shown in the drawings in which the piston rod 92b connected to the third slide table 90 protrudes and retracts from the cylinder 92a to move the third slide table 90 in the directions of arrows Z1 and Z2 along the rotation axis R1. Although the structure to move was illustrated, it is not limited to this. In short, any device that can move the third slide table 90 in the directions of the arrows Z1 and Z2 along the rotation axis R1 may be used.

  The movement control device includes a single ball screw 94 that is rotatably fixed on the third slide table 90 and extends in parallel along the rotation axis R1, and a third motor 96 that rotates the ball screw 94. The first and second slide tables 22 and 40 are connected to each other via a ball screw 94. The first and second slide tables 22 and 40 are integrally provided with first and second slider portions 22s and 40s, respectively. The slider portions 22s and 40s are provided with ball screws 94, respectively. A plurality of balls (not shown) that roll and rotate are incorporated so as to be circulated.

  Here, in the ball screw 94, on the first slide table 22 side, one first ball screw groove G1 in which a plurality of balls incorporated in the first slider portion 22s roll and rotate is formed in a spiral shape. On the other hand, on the second slide table 40 side, one second ball screw groove G2 in which a plurality of balls incorporated in the second slider portion 40s roll and rotate is formed in a spiral shape. The first and second ball screw grooves G1 and G2 pivot in opposite directions, and the first ball screw groove G1 and the second ball screw groove G2 are set to the same lead (pitch). .

  In this case, when the ball screw 94 is rotated in the forward direction by the third motor 96, the first and second slider portions 22s, 40s are moved in the direction of the arrow X1, thereby the first and second slide tables 22 are moved. , 40 move in the direction of the arrow X1 along the rotation axis R1, the first and second grindstones 6, 8 can be brought closer to each other along the rotation axis R1. On the other hand, when the ball screw 94 is rotated in the reverse direction by the third motor 96, the first and second slider portions 22s and 40s move in the direction of the arrow X2, thereby the first and second slides. By moving the tables 22 and 40 in the direction of the arrow X2 along the rotation axis R1, the first and second grindstones 6 and 8 can be separated from each other along the rotation axis R1.

Next, a work peripheral surface grinding method using the work peripheral surface grinding machine described above will be described.
First, in a state where the outer ring 2 is set (held) on the rotation holding mechanism, the rotation holding mechanism is moved to the arrows Y1, Y2, and the first and second grindstones 6, 8 can be inserted into the inner diameter side of the outer ring 2. The outer ring 2 is positioned at a proper position.

  Next, the piston rod 92b is protruded from the cylinder 92a, and the third slide table 90 is moved along the rotation axis R1 in the direction of the arrow Z1, whereby the first and second rotation control mechanisms described above are moved to the rotation axis. By moving in the arrow Z1 direction along R1, both the first and second grindstones 6 and 8 are inserted from one side (inboard side) of the outer ring 2 to the inner diameter side of the outer ring 2. At this time, the insertion positions of the first and second grindstones 6 and 8 are finely adjusted by rotating the ball screw 94 in the forward and reverse directions by the third motor 96.

  At this time, the insertion positions of the first and second grindstones 6 and 8 are determined based on the first and second grindstones 6 and 8 (specifically, the first and second raceway surface grinding portions 60 and 8). 80) can be cut with respect to the first and second raceway surfaces 2t, 2s of the outer ring 2 at the same timing (moving speed, moving amount). Since the other work peripheral surface grinding method is the same as that in the first embodiment, the description thereof is omitted.

  As described above, according to the present embodiment, the work peripheral surface grinding machine in the direction along the rotation axis R1 can be made compact by inserting the second spindle 4b into the first spindle 4a. In this case, since the first spindles 4a and 4b are configured so as not to be relatively rotatable about the rotation axis R1, the first and second spindles 4a can be obtained only by the first rotating device (the first motor 24 and the like). , 4b (first and second grindstones 6, 8) can be rotated simultaneously. This eliminates the need for the second rotating device (such as the second motor 42) required in the first embodiment described above, and reduces the number of parts by that amount. As a result, the work peripheral grinder Manufacturing cost can be reduced.

  Further, according to the present embodiment, in the fast-forward mechanism (movement control device), the first and second slide tables 22 and 40 are moved in the directions of the arrows X1 and X2 only by rotating one ball screw 94 in the forward and reverse directions. The first and second grindstones 6 and 8 can be moved closer to or away from each other. Thereby, it is possible to move and control the first and second grindstones 6 and 8 (first and second slide tables 22 and 40) with extremely high accuracy while having a simple and inexpensive configuration.

  Further, according to the present embodiment, in the rapid feed mechanism (rapid feed device), the third slide table 90 is moved in the direction of the arrow Z1 only by projecting the piston rod 92b from the cylinder 92a, and the first and second Both the grindstones 6 and 8 can be inserted into the inner diameter side of the outer ring 2. As a result, the time required to insert the first and second grindstones 6 and 8 into the inner diameter side of the outer ring 2 can be shortened, so that the time required for the grinding process (cycle time) can be reduced by that amount. (Compared to the first embodiment described above).

  Further, in the rotation holding mechanism applied to the first embodiment described above, the first grindstone 6 is moved from one side (inboard side) of the outer ring 2 and the second grindstone 8 is rotated and held by the suction plate 12 (suction plate 12). ), The suction plate 12 must be configured to be hollow from the other side (outboard side) of the outer ring 2 to the inner diameter side of the outer ring 2.

  However, according to the present embodiment, since both the first and second grindstones 6 and 8 can be inserted from one side (inboard side) of the outer ring 2 to the inner diameter side of the outer ring 2, the suction plate 12 is It is not necessary to form a hollow structure, and the conventional rotation holding mechanism (the suction plate 12 and the holding member 14) can be used as it is. Thereby, since the rigidity of the suction plate 12 can be held constant, the outer ring 2 can be stably held by the rotation holding mechanism.

  In the above-described second embodiment (FIG. 2), the first and second rotation control mechanisms are provided on the third slide table 90. Instead, for example, as shown in FIG. As described above, the first and second rotation control mechanisms may be provided on the first rotation control mechanism (first slide table 22). In such a configuration, since both the housing 32 and the second rotation control mechanism are built on the first rotation control mechanism, both the housings 32 and 50 can be easily aligned. When such a configuration is adopted, the lead (pitch) of the second ball screw groove G2 may be set to be twice the lead (pitch) of the first ball screw groove G1.

  In the first and second embodiments described above, the method for forming the first and second grindstones 6 and 8 is not particularly mentioned. For example, in an existing rotary dressing device, the outer diameter of the diamond wheel is reduced. The wheel is pressed against the grindstone, and the surface of the grindstone is truing into a contour shape obtained by inverting the inner peripheral surface 2m of the outer ring 2 (first and second raceway surfaces 2t, 2s, first and second cylindrical surfaces Ft, Fs) By dressing, the first and second grindstones 6 and 8 can be formed.

  As another molding method, for example, in a rotary dress wheel having the same shape as the outer ring 2, the inner diameter (diamond layer) of the inner ring 2m (first and second raceway surfaces 2t, 2s, In the state where the diamond wheel formed in the same contour shape as the first and second cylindrical surfaces Ft, Fs) is held by the rotation holding mechanism (the suction plate 12, the holding member 14), the grindstone is attached to the diamond wheel. An outline in which the grindstone surface is pressed against the inner diameter (diamond layer) and the inner circumferential surface 2m (first and second raceway surfaces 2t, 2s, first and second cylindrical surfaces Ft, Fs) of the outer ring 2 is inverted. The first and second grindstones 6 and 8 can be formed by truing and dressing the shape. In the other forming method, the rotational speed of the rotation holding mechanism (suction plate 12) may be adjusted depending on whether grinding is performed on the inner peripheral surface 2m of the outer ring 2 or truing and dressing of the grindstone surface. .

  In the first and second embodiments (FIGS. 1 and 2) and the modification (FIG. 3) described above, double row outer ring raceway surface grinding with respect to the inner peripheral surface 2m of the workpiece (the outer ring 2 as an example in the drawing) is performed. However, it goes without saying that such a grinding technique can also be applied to double row inner ring raceway surface grinding with respect to the outer peripheral surface of a workpiece (inner ring not shown).

2 Outer ring (work)
2 m Outer ring inner peripheral surface 6 First grindstone 8 Second grindstone R1 Rotating shaft

Claims (5)

A pair of grindstones configured to be rotatable around a single rotation axis, and to grind the peripheral surface of the workpiece,
A rotation control mechanism for rotating both the grindstones at the same time while relatively moving both of the grindstones in the direction of approaching or separating from each other along the rotation axis;
In a state where the workpiece is rotated, a grinding process for the peripheral surface of the workpiece is performed by bringing the pair of rotated grindstones into contact with the peripheral surface while approaching or separating from each other along a direction crossing the peripheral surface of the workpiece. A work surface grinder characterized by: A pair of grooves that are continuously depressed in an arc shape along the circumferential direction are formed on the peripheral surface of the workpiece, and each of the pair of grindstones is provided with a groove grinding portion that performs grinding processing on the grooves. And
In a state where the workpiece is rotated, a grinding process for the peripheral surface of the workpiece is performed by bringing the pair of rotated grindstones into contact with the peripheral surface while approaching or separating from each other along a direction crossing the peripheral surface of the workpiece. 2. The work surface grinding machine according to claim 1, wherein each groove grinding portion is cut toward a center direction of each groove or a contact angle direction intersecting with each groove. The workpiece is held by a rotation holding mechanism that rotates the workpiece around the rotation axis and moves the workpiece along a direction orthogonal to the rotation axis.
While moving the workpiece rotated by the rotation holding mechanism along the direction orthogonal to the rotation axis, the pair of grindstones rotated by the rotation control mechanism are moved closer to or away from each other along the direction crossing the peripheral surface of the workpiece. The workpiece peripheral surface grinding machine according to claim 1, wherein the peripheral surface of the workpiece is ground by being brought into contact with the peripheral surface.   The workpiece is a bearing race ring that is disposed so as to be relatively rotatable via rolling elements incorporated in a double row, and a groove for rolling the rolling element is formed on the circumferential surfaces facing each other. The workpiece peripheral surface grinding machine according to any one of claims 1 to 3, wherein the workpiece circumferential grinder is formed in a double row by being continuously depressed in an arc shape along the circumferential direction. A workpiece peripheral surface grinding method using the workpiece peripheral surface grinding machine according to any one of claims 1 to 4,
In a state where the workpiece is rotated, a grinding process for the peripheral surface of the workpiece is performed by bringing the pair of rotated grindstones into contact with the peripheral surface while approaching or separating from each other along a direction crossing the peripheral surface of the workpiece. A work surface grinding method characterized in that:

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