Burnishing equipment and rollers

Abstract

Improving the stability of rolling machine parts performance [Solution] The burnishing processing device 400 processes a workpiece having a track forming surface 401 on which the track of a spherical rolling element 130 is formed, and is equipped with a roller 410 having a rotation axis 402 in a direction perpendicular to the extension direction of the track and pressed against the track forming surface 401 to plastically deform the workpiece, and the roller 410, in a cross section including the rotation axis 402, has a convex arc-shaped portion 411 which is part of an imaginary circle which is the same as or nearly the same as the cross-sectional circle passing through the center of the spherical rolling element 130, and escape portions 412 extending from both ends of the convex arc-shaped portion 411 so as to move away from the convex arc-shaped portion 411 along the imaginary circle and move away from the imaginary circle as they move away from the convex arc-shaped portion 411.

Description

[Technical Field]

[0001] The present invention relates to a burnishing device for burnishing the track of a rolling machine part in which two members move relatively with a spherical rolling element sandwiched therebetween, and to a roller. [Background technology]

[0002] For example, Patent Document 1 describes a technique for burnishing the track of a rolling machine part in which two members move relatively with a spherical rolling element sandwiched therebetween, using a spherical rolling element for processing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6365796 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors discovered that among rolling machine parts equipped with burnished members, some show a decline in performance after a certain period of use, and some have a shorter lifespan than other rolling machine parts. As a result of conducting extensive experiments and research to determine the cause of these defects, they discovered that the defects occur when part of the raised portion caused by the burnishing breaks off and gets into the raceway.

[0005] The present invention has been made based on the findings of the inventors, and provides a burnishing device and a roller that can improve the stability of the performance of rolling machine parts. [Means for solving the problem]

[0006] One aspect of the present invention is a burnishing device that processes a workpiece having a track formation in which a track of a spherical rolling element is formed, and is equipped with a roller that has a rotation axis in a direction perpendicular to the extension direction of the track and is pressed against the track formation surface to plastically deform the workpiece, and the roller has, in a cross section including the rotation axis, a convex arc-shaped portion that is part of an imaginary circle that is the same as or nearly the same as a cross-sectional circle passing through the center of the spherical rolling element, and a relief portion that extends from both ends of the convex arc-shaped portion so as to move away from the imaginary circle as it moves away from the convex arc-shaped portion along the imaginary circle.

[0007] One aspect of the present invention is a roller used in a burnishing device that processes a workpiece having a track-forming surface on which a track of a spherical rolling element is formed, and has a rotation axis in a direction perpendicular to the extension direction of the track, and is pressed against the track-forming surface to plastically deform the workpiece, and the roller has, in a cross section including the rotation axis, a convex arc-shaped portion that is part of an imaginary circle that is the same as, or nearly the same as, a cross-sectional circle passing through the center of the spherical rolling element, and escape portions that extend from both ends of the convex arc-shaped portion so as to move away from the imaginary circle as they move away from the convex arc-shaped portion along the imaginary circle. [Effects of the Invention]

[0008] According to the present invention, the stability of the performance of rolling machine components can be improved. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a rolling machine part having a workpiece that has been burnished. [Figure 2] FIG. 2 is a side view of a rolling machine part having a burnished workpiece. [Figure 3] FIG. 3 is a perspective view showing a burnishing device that burnishes the first member. [Figure 4]FIG. 4 is a side view showing a burnishing device that burnishes the first member. [Figure 5] FIG. 5 is a perspective view showing a burnishing device that burnishes the second member. [Figure 6] FIG. 6 is a side view showing a burnishing device that burnishes the second member. [Figure 7] FIG. 7 is a cross-sectional view of the roller and the workpiece taken along a plane that includes the rotation axis and is perpendicular to the direction of movement of the roller. [Figure 8] FIG. 8 is an enlarged cross-sectional view of a part of FIG. [Figure 9] FIG. 9 is a flowchart showing the flow of the burnishing method. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a burnishing apparatus and a roller according to the present invention will be described with reference to the drawings. Note that the following embodiments are presented as examples for the purpose of explaining the present invention and are not intended to limit the present invention. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical formulas, the content of each step in a method, and the order of each step shown in the following embodiments are merely examples and may include content not described below. Furthermore, while geometric expressions such as parallel and orthogonal may be used, these expressions do not imply mathematical precision and include substantially acceptable errors and deviations. Furthermore, expressions such as simultaneous and identical also include substantially acceptable ranges.

[0011] The drawings are schematic diagrams in which emphasis, omission, or adjustment of proportions is appropriately made for the purpose of explaining the present invention, and differ from the actual shapes, positional relationships, and proportions. The X-axis, Y-axis, and Z-axis shown in the drawings represent Cartesian coordinates arbitrarily set for the purpose of explaining the drawings. In other words, the Z-axis is not necessarily an axis along the vertical direction, and the X-axis and Y-axis are not necessarily located within a horizontal plane.

[0012] In addition, in the following, multiple inventions may be collectively described as one embodiment, and some of the contents described below may be described as optional components related to the present invention.

[0013] FIG. 1 is a perspective view showing a rolling machine component 100 including a burnished workpiece. FIG. 2 is a side view showing the rolling machine component 100 including a burnished workpiece. The rolling machine component 100 is a machine component in which two members move relatively to each other, sandwiching a member that performs rolling motion. The type of rolling machine component 100 is not limited. Examples of the rolling machine component 100 include a ball bearing and a ball screw. In this embodiment, a ball slide rail, which is one type of rolling machine component 100, will be described as an example. The rolling machine component 100 includes a first member 110 that is a workpiece, a second member 120 that is also a workpiece, and a spherical rolling element 130.

[0014] There are no limitations on the shape or structure of the first member 110, which is a component of the rolling machine component 100. In the case of this embodiment, the first member 110 is a rail formed by subjecting a sheet metal material to bending processing such as press processing or roll forming, and includes a first track 113. The first member 110 also includes a first base portion 111, a first arm portion 112, and the first track 113.

[0015] In the present embodiment, the rolling machine component 100 is a ball slide rail, and the first member 110 is a so-called inner rail.

[0016] The first base portion 111 is a portion that is fixed to another member. The first base portion 111 is a flat, band-like plate, and is provided with first fixing holes 115 at a plurality of locations, through which the fastening members 200 are pierced.

[0017] The first arm portions 112 are portions that rise from both edge portions in the width direction (Z-axis direction in the drawing) of the first base portion 111 toward the thickness direction (X-axis direction in the drawing) of the first base portion 111. The first arm portions 112 are formed by bending a metal plate material of uniform thickness, leaving the first base portion 111, so that they rise at both end portions in the width direction.

[0018] The first raceway 113 is a portion through which the spherical rolling elements 130 pass, and is formed by bending the first arm portion 112. In the present embodiment, the first raceway 113 is formed as a V-shaped groove that opens outward in the width direction, is recessed inward in the width direction, and extends in the sliding direction (the Y-axis direction in the figure). A pair of first abutment portions 114 with which the spherical rolling elements 130 abut is provided on the two raceway forming surfaces 401 of the first raceway 113. The first abutment portions 114 are provided by plastic deformation using burnishing, which will be described later.

[0019] The shape and structure of the second member 120, which is a component of the rolling machine component 100, are not limited. In the present embodiment, the second member 120 is a member formed by pressing a metal sheet or performing bending processing such as roll forming, similar to the first member 110, and includes a second track 123 that faces the first track 113. In a state in which the rolling machine component 100 is assembled (see FIG. 1), the second member 120 is a member that is slidable relative to the first member 110 in the longitudinal direction (the Y-axis direction in the drawing). The second member 120 includes a second base portion 121, a second arm portion 122, and a second track 123. In the present embodiment, the second member 120 is a so-called outer rail.

[0020] The second base portion 121 is a portion that is fixed to a member different from the member to which the first base portion 111 is fixed. The second base portion 121 is a flat band-like plate that is wider than the first base portion 111, and is provided with second fixing holes (not shown) at multiple locations, through which the fastening members 200 are pierced.

[0021] The second arm portions 122 are portions that rise from both edge portions in the width direction (Z-axis direction in the drawing) of the second base portion 121 toward the thickness direction (X-axis direction in the drawing) of the second base portion 121. The second arm portions 122 are formed by bending a metal plate material of uniform thickness, leaving the second base portion 121, so that they rise at both end portions in the width direction. When the rolling machine component 100 is in an assembled state, the second arm portions 122 are arranged outside the first arm portions 112.

[0022] The second raceway 123 is a portion through which the spherical rolling elements 130 pass, and is formed by bending the second arm portion 122. In the present embodiment, the second raceway 123 is formed so as to form a V-shaped groove that opens toward the inside in the width direction, is recessed toward the outside in the width direction, and extends in the sliding direction. The second raceway 123 is disposed so as to face the first raceway 113 when the rolling machine component 100 is in an assembled state. A pair of second abutment portions 124, with which the spherical rolling elements 130 abut, are provided on two surfaces of the second raceway 123. The second abutment portions 124 are provided by plastic deformation using burnishing, which will be described later.

[0023] The spherical rolling body 130 is a spherical member that is rotatably interposed between a first raceway 113 provided on the first member 110 and a second raceway 123 provided on the second member 120 so as to face the first raceway 113.

[0024] In this embodiment, the rolling machine component 100 is a ball slide rail, and multiple spherical rolling bodies 130 are arranged side by side in the extension direction of the first member 110 (Y-axis direction in the figure) (the same applies to the extension direction of the second member 120), and are rotatably held by a retainer 139.

[0025] Fig. 3 is a perspective view showing a burnishing apparatus 400 that burnishes the first member 110. Fig. 4 is a side view showing the burnishing apparatus 400 that burnishes the first member 110. Fig. 5 is a perspective view showing the burnishing apparatus 400 that burnishes the second member 120. Fig. 6 is a side view showing the burnishing apparatus 400 that burnishes the second member 120.

[0026] The burnishing device 400 is a device that performs burnishing on the track-forming surfaces 401 (see FIGS. 4 and 6) of the first member 110 and the second member 120, which are workpieces, to form the first contact portion 114 and the second contact portion 124 (see FIGS. 7 and 8), and is equipped with a roller 410 and a pressure moving device (not shown) that moves the roller 410 and the workpiece relatively while pressing the roller 410 against the workpiece. In this embodiment, the burnishing device 400 is equipped with a support jig 420 and a holding jig 430.

[0027] Roller 410 has a rotation axis 402 in a direction (X-axis direction in the figure) perpendicular to the direction in which the track extends (Y-axis direction in the figure), and is pressed against track-forming surface 401 to plastically deform the workpiece. FIG. 7 is a cross-sectional view of roller 410 and the workpiece cut along a plane that includes rotation axis 402 and is perpendicular to the direction in which roller 410 moves. FIG. 8 is a cross-sectional view showing an enlarged portion of FIG. 7. As shown in these figures, roller 410 has, in a cross section including rotation axis 402, convex arc-shaped portion 411 that is part of an imaginary circle (shown by a two-dot chain line in the figure) that is the same as or nearly the same as the cross-sectional circle that passes through the center of spherical rolling element 130, and relief portions 412 that extend from both ends of convex arc-shaped portion 411 along the imaginary circle and move away from imaginary circle as the distance from convex arc-shaped portion 411 increases.

[0028] The convex arc-shaped portion 411 is a portion that abuts against the raceway forming surface 401 that forms the first raceway 113, and plastically deforms the first member 110 so as to form a groove having an arc-shaped cross section on the raceway forming surface 401. By rotating about the rotation axis 402, the convex arc-shaped portion 411 abuts against the raceway forming surface 401 in a state similar to the state in which the spherical rolling elements 130 roll on the raceway forming surface 401.

[0029] The relief portion 412 is a portion that pushes and stretches the protruding portion 413, which protrudes as a result of the convex arc-shaped portion 411 plastically deforming the raceway-forming surface 401, away from the first abutment portion 114. By pushing and stretching the protruding portion 413 away from the first abutment portion 114, contact between the spherical rolling element 130 and the end 414 of the protruding portion 413 is suppressed when the spherical rolling element 130 rolls on the raceway-forming surface 401, and stress generated in the protruding portion 413 when the spherical rolling element 130 rolls on the raceway-forming surface 401 is reduced, thereby making it possible to suppress fatigue fracture of the end 414 of the protruding portion 413. Furthermore, even if the protruding portion 413 breaks off, it is possible to prevent broken fragments from entering the first abutment portion 114, making it possible to handle the rolling machine component 100 stably for a long period of time.

[0030] The relief portion 412 is a portion that extends from the end of the convex arc-shaped portion 411 in a cross section including the rotation axis 402, and is a portion that is formed so as to gradually move away from the track-forming surface 401 as it moves away from the convex arc-shaped portion 411. In the case of this embodiment, the relief portion 412 once moves away from the track-forming surface 401, and then moves closer to it again.

[0031] The shape of the recess 412 is not limited as long as it complies with the above content, and it may be linear. In the case of this embodiment, the recess 412 has a curved concave shape. This allows the surface of the raised portion 413 to smoothly connect with the first abutment portion 114 formed by the convex arc-shaped portion 411. This makes it possible for the spherical rolling element 130 to smoothly return to the first abutment portion 114 even if the spherical rolling element 130 is slightly shaken and rides up onto the raised portion 413 while the rolling machine component 100 is in use.

[0032] In this embodiment, roller 410 has two sets of a convex arc-shaped portion 411 and a pair of relief portions 412 on one side (the lower side in the figure) separated by rotation axis 402 in a cross section including rotation axis 402. The two convex arc-shaped portions 411 are arranged on one circle (the cross section of spherical rolling element 130). This allows first contact portions 114 to be formed on each of the two raceway forming surfaces 401 of first raceway 113.

[0033] 7 and 8 show the shape of roller 410 applied to first member 110, but in the present embodiment, the shape of roller 410 applied to second member 120 is the same as the shape of roller 410 applied to first member 110. Therefore, second contact portions 124 are formed by rollers 410 on each of the two track-forming surfaces 401 of second track 123, and raised portions 413 are formed on both sides of second contact portions 124 by relief portions 412, which are pushed and extended away from second contact portions 124.

[0034] Next, a burnishing method using the burnishing apparatus 400 will be described. Fig. 9 is a flowchart showing the flow of the burnishing method. First, a workpiece is attached to the burnishing apparatus 400 (S101). For example, in the case of a first member 110, which is the workpiece, the first member 110 is attached to a holding jig 430 using a fastening member 200 or the like. In the case of a second member 120, the second member 120 is attached to a holding jig 430 that is integrated with a support jig 420.

[0035] Next, if the portion of the workpiece to be burnished is elastic, or if the workpiece cannot withstand the pressure during burnishing, the portion to be burnished of the workpiece is supported by a support jig 420 (S102). For example, as shown in Fig. 4, in the case of the first member 110, the support jig 420 is placed on the opposite side of the roller 410 with respect to the first track 113, and supports the first arm 112 so as not to bend. In the case of the second member 120, as shown in Fig. 6, the support jig 420 is placed on the opposite side of the roller 410 with respect to the second track 123, and supports the second arm 122 so as not to bend.

[0036] Next, the burnishing device 400 is operated by moving the roller 410 while pressing the roller 410 against a predetermined location on the workpiece using the pressure-transfer device (S103). For example, in the case of the first member 110, the roller 410 is moved in the extension direction of the first track 113 while being pressed against a pair of track-forming surfaces 401 at once, and a pair of first abutment portions 114 are simultaneously formed by burnishing. Similarly, in the case of the second member 120, the roller 410 is moved in the extension direction of the second track 123 while being pressed against a pair of track-forming surfaces 401 at once, and a pair of second abutment portions 124 are simultaneously formed by burnishing. Note that, depending on the shape of the second member 120, the pressure-transfer device presses the roller 410 in a cantilevered state against the track-forming surfaces 401 of the second member.

[0037] Next, an adjustment process is performed using the same rollers 410 (S104). In the adjustment process, the rollers 410 are pressed against a pair of track-forming surfaces 401 with a load lower than that used in burnishing, and rotated relative to each other multiple times. This suppresses initial deformation of the track-forming surfaces 401 when used as the mechanical component 100, thereby stabilizing the surface. As a result, the track-forming surfaces 401 are formed with a first contact portion 114 and a second contact portion 124, respectively. Furthermore, protruding portions 413, which have been raised by plastic deformation, extend from both sides of the first contact portion 114 and the second contact portion 124. The shape of the protruding portions 413 is formed to conform to the shape of the recessed portions 412.

[0038] The present invention is not limited to the above-described embodiments. For example, the present invention may be embodied in another embodiment by arbitrarily combining the components described in this specification or by excluding some of the components. Furthermore, the present invention also includes various modifications that would occur to a person skilled in the art without departing from the spirit of the present invention, i.e., the meaning of the wording of the claims.

[0039] For example, since the first member 110 has a pair of first tracks 113, burnishing may be performed using rollers 410 on each of the first tracks 113. Also, burnishing may be performed simultaneously on the pair of first tracks 113 using multiple rollers 410. The second member 120 also has a pair of second tracks 123, and similar burnishing may be performed on them.

[0040] Furthermore, although the rolling machine component 100 in which the spherical rolling element 130 makes contact at four points has been exemplified, the rolling machine component 100 in which the spherical rolling element 130 makes contact at two points or three points may also be used. In other words, the roller 410 may be provided with one convex arc-shaped portion 411 on one side divided by the rotation axis 402 in a cross section including the rotation axis 402.

[0041] (summary) The burnishing processing device 400 of the first embodiment is a burnishing processing device 400 that processes a workpiece having a track forming surface 401 on which the track of the spherical rolling element 130 is formed, and is equipped with a roller 410 that has a rotation axis 402 in a direction perpendicular to the extension direction of the track and is pressed against the track forming surface 401 to plastically deform the workpiece, and the roller 410, in a cross section including the rotation axis 402, has a convex arc-shaped portion 411 that is part of an imaginary circle that is the same as or nearly the same as the cross-sectional circle passing through the center of the spherical rolling element 130, and escape portions 412 that extend from both ends of the convex arc-shaped portion 411 so as to move away from the convex arc-shaped portion 411 along the imaginary circle and move away from the imaginary circle as they move away from the convex arc-shaped portion 411.

[0042] According to the first aspect, burnishing with roller 410 can push and stretch the protruding portions on both sides of the plastically deformed portion so that they move outward by recess 412. This makes it possible to prevent fragments from entering the plastically deformed portion even if a defect occurs in the protruding portion.

[0043] The second embodiment of the burnishing processing apparatus 400 includes the first embodiment, and the roller 410 has two sets of a convex arc-shaped portion 411 and a pair of recesses 412 on one side separated by the rotation axis 402 in a cross section including the rotation axis 402.

[0044] According to the second aspect, it is possible to form a track that makes two-point contact with the spherical rolling element 130 at once.

[0045] The burnishing device 400 of the third embodiment includes the first embodiment or the second embodiment, and the recess 412 has a curved concave shape.

[0046] According to the third aspect, the plastic deformation portion formed by the convex arc-shaped portion 411 and the surface of the protruding portion beside it can be smoothly connected, making it possible to flexibly respond to vibration of the spherical rolling element 130 when the rolling mechanical component 100 is used.

[0047] The roller 410 of the fourth embodiment is used in a burnishing device 400 that processes a workpiece having a track forming surface 401 on which the track of the spherical rolling element 130 is formed, and has a rotation axis 402 in a direction perpendicular to the extension direction of the track, and is pressed against the track forming surface 401 to plastically deform the workpiece, and in a cross section including the rotation axis 402, the roller 410 has a convex arc-shaped portion 411 that is part of an imaginary circle that is the same as or nearly the same as the cross-sectional circle passing through the center of the spherical rolling element 130, and escape portions 412 that extend from both ends of the convex arc-shaped portion 411 so as to move away from the convex arc-shaped portion 411 along the imaginary circle and move away from the imaginary circle as they move away from the convex arc-shaped portion 411.

[0048] According to the fourth aspect, burnishing using the roller 410 can push and stretch the protruding portions on both sides of the plastically deformed portion so that they move outward by the relief portions 412. This makes it possible to prevent fragments from entering the plastically deformed portion even if a defect occurs in the protruding portion. [Industrial Applicability]

[0049] The present invention can be applied to the general manufacture of rolling machine parts in which two members move relatively with a spherical rolling element sandwiched therebetween. [Explanation of symbols]

[0050] 100... rolling machine part, 110... first member, 111... first base portion, 112... first arm portion, 113... first raceway, 114... first abutment portion, 115... first fixing hole, 120... second member, 121... second base portion, 122... second arm portion, 123... second raceway, 124... second abutment portion, 130... spherical rolling element, 139... retainer, 200... fastening member, 400... burnishing processing device, 401... raceway forming surface, 402... rotating shaft, 410... roller, 411... convex arc-shaped portion, 412... relief portion, 413... raised portion, 414... end portion, 420... supporting jig, 430... holding jig

Claims

1. A burnishing device for processing a workpiece having a raceway forming surface on which raceways of spherical rolling elements are formed, a roller having a rotation axis in a direction perpendicular to the extending direction of the track and pressed against the track forming surface to plastically deform the workpiece; The roller has, in a cross section including the rotation axis, a convex arc-shaped portion that is a part of a virtual circle that is the same as or nearly the same as a cross-sectional circle that passes through the center of the spherical rolling element; a relief portion extending from each end of the convex arc-shaped portion so as to move away from the convex arc-shaped portion along the imaginary circle and toward the outside of the imaginary circle as the relief portion moves away from the convex arc-shaped portion along the imaginary circle. Burnishing processing equipment.

2. The roller has, in a cross section including the rotation axis, Two pairs of the convex arc-shaped portion and a pair of relief portions are provided on one side divided by the rotation axis. The burnishing device according to claim 1 .

3. The relief portion has a curved concave shape. The burnishing device according to claim 1 or 2.

4. A roller used in a burnishing device for processing a workpiece having a raceway-forming surface on which a raceway of a spherical rolling element is formed, the roller having a rotation axis in a direction perpendicular to the extending direction of the raceway, and pressed against the raceway-forming surface to plastically deform the workpiece, The roller has, in a cross section including the rotation axis, a convex arc-shaped portion that is a part of a virtual circle that is the same as or nearly the same as a cross-sectional circle that passes through the center of the spherical rolling element; a relief portion extending from each end of the convex arc-shaped portion so as to move away from the convex arc-shaped portion along the imaginary circle and toward the outside of the imaginary circle as the relief portion moves away from the convex arc-shaped portion along the imaginary circle. roller.

Images