Linear motion guide device and manufacturing method thereof

Abstract

To provide a linear motion guide device capable of securing smooth ball movement while mitigating impact force regardless of the behavior of a ball entering a track surface, and a manufacturing method thereof.SOLUTION: In a linear motion guide device, when a plane passing through a widthwise center of a slider body and a longitudinal axial line of a guide rail is defined as a vertical center plane CP, a plane perpendicular to the vertical center plane CP and passing through a center line of a straight part of a rolling passage is defined as a horizontal reference plane HP, and a plane parallel to the vertical center plane CP and intersecting a second inclined surface and a third inclined surface is defined as a vertical reference plane VP, a point P2 on a first inclined plane that is farthest from the vertical reference plane VP is farther away from the vertical reference plane VP than a point P1 on a first raceway plane that is farthest from the vertical reference plane VP, and a point P4 on the second inclined surface and third inclined surface that is farthest from the horizontal reference plane HP is farther away from the horizontal reference plane HP than a point P3 on the first raceway plane that is farthest from the horizontal reference plane HP.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a linear guide device and a method for manufacturing the same.

Background Art

[0002] A linear guide device that linearly guides a guided object while infinitely circulating rolling elements such as rollers and balls inside is an important mechanical element that greatly affects the motion accuracy of semiconductor manufacturing devices, ultra-precision machining machines, ultra-precision measuring instruments, and the like.

[0003] The linear guide device includes a guide rail and a slider body. A rail-side rolling element raceway groove is provided in the guide rail. A slider-side rolling element raceway groove facing the rail-side rolling element raceway groove is provided in the slider body, and the slider body is supported by the guide rail so as to be axially movable through the rolling of a plurality of rolling elements disposed in a rolling passage formed between the slider-side rolling element raceway groove and the rail-side rolling element raceway groove. The linear guide device further includes a rolling element return passage provided in the slider body so as to be substantially parallel to the rolling passage, and a direction conversion passage provided in end caps attached to both ends in the moving direction of the slider body to communicate the rolling passage and the rolling element return passage.

[0004] When the rolling elements of the linear guide device infinitely circulate through the rolling passage, the direction conversion passage, and the rolling element return passage, periodic minute vibrations (hereinafter referred to as rolling element passing vibrations) occur, which greatly affects the motion accuracy of the above-described devices. The rolling element passing vibration occurs when the load on the rolling element rolling in the rolling passage (load region) while receiving a load due to preload or an external load is released when the rolling element exits from the load region to the rolling element circulation path (non-load region), or conversely, when a new load is borne when entering from the non-load region to the load region.

[0005] In order to suppress this rolling element passing vibration, inclined surfaces called crowning are provided at both ends of the slider-side rolling element raceway groove forming the rolling passage. By gradually changing the load fluctuation associated with the entry and exit of the rolling element into and out of the load region by crowning, the rolling element passing vibration can be reduced.

[0006] Patent Document 1 discloses a linear motion guide bearing including a first crowning having a curved surface shape formed with a large radius of curvature such that the inclined portions provided at both ends of the slider-side rolling element raceway groove are continuously formed with a gentle inclination from the slider-side rolling element raceway groove, a second crowning that is adjacent to the first crowning and has a steeper inclination than the first crowning extending toward the inner peripheral surface of the direction change path and is shorter than the first crowning in the axial direction, and an inclined surface provided between the second crowning and the end surface of the slider body and inclined more than the first crowning and the second crowning.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] By the way, when the ball enters the return passage, so-called eccentricity of the ball, in which the center of the ball is displaced with respect to the center line of the return passage, may be a problem. According to the technique of Patent Document 1, by combining the first crowning and the second crowning, a sufficient amount of drop can be formed in the groove bottom direction in which the crowning is formed to allow the eccentricity of the ball to escape. However, since the slider groove end portion cannot provide relief for the eccentricity of the ball in a direction other than the groove bottom direction, particularly in a direction perpendicular to the groove bottom, the ball may strongly collide with the end surface of the slider, which may deteriorate the durability.

[0009] The present invention has been made in view of the above problems, and an object thereof is to provide a linear motion guide device and a method for manufacturing the same that can ensure smooth movement of the ball while reducing the impact force regardless of the behavior of the ball entering the raceway surface.

Means for Solving the Problems

[0010] The linear guide device of the present invention is a guide rail, a slider arranged to move relative to the guide rail in the longitudinal direction, and a plurality of rolling elements arranged to roll freely along a rolling path formed between the guide rail and the slider, and is a linear guide device comprising: the slider comprises a slider body having a raceway groove facing the raceway groove of the guide rail to form the rolling path of the rolling element and a return path for the rolling element, and an end cap having a direction-changing path connecting the return path and the rolling path, the raceway groove of the slider body has a first raceway surface on the central portion side of the rolling path and a second raceway surface on the end portion side of the rolling path, the second raceway surface has a first inclined surface extending from the first raceway surface to the end face of the slider body, and a second inclined surface and a third inclined surface extending to the end face of the slider body or its vicinity without being continuous with the first raceway surface, when a plane passing through the center in the width direction of the slider body and the longitudinal axis of the guide rail is defined as a vertical center plane CP, a plane perpendicular to the vertical center plane CP and passing through the center line of the straight portion of the rolling path is defined as a horizontal reference plane HP, and a plane parallel to the vertical center plane CP and intersecting the second inclined surface and the third inclined surface is defined as a vertical reference plane VP, a point P2 on the first inclined surface farthest from the vertical reference plane VP is spaced apart from the vertical reference plane VP more than a point P1 on the first raceway surface farthest from the vertical reference plane VP, and a point P4 on the second inclined surface and the third inclined surface farthest from the horizontal reference plane HP is spaced apart from the horizontal reference plane HP more than a point P3 on the first raceway surface farthest from the horizontal reference plane HP, which is characterized in that.

[0011] A method for manufacturing the linear guide device of the present invention is a guide rail, a slider arranged to move relative to the guide rail in the longitudinal direction, A method for manufacturing a linear guide device including a plurality of rolling elements that are arranged to be rollable along a rolling path formed between the guide rail and the slider, The slider includes: A slider body that is disposed opposite to the raceway groove of the guide rail to form a rolling path for the rolling elements, and has a return path for the rolling elements, An end cap having a direction-changing path that connects the return path and the rolling path, The raceway groove of the slider body has a first raceway surface on the central portion side of the rolling path and a second raceway surface on the end portion side of the rolling path, The second raceway surface has a first inclined surface that extends from the first raceway surface to the end surface of the slider body, and a second inclined surface and a third inclined surface that extend to the end surface of the slider body or the vicinity thereof without being continuous with the first raceway surface, The slider body has a body portion and a pair of leg portions disposed at both ends in the width direction of the body portion, When the width direction of the slider body is the X direction, the longitudinal direction of the slider body is the Y direction, and the direction orthogonal to the X direction and the Y direction is the Z direction, A step of forming the first raceway surface by moving a tool having an annular grinding wheel that rotates around a rotation axis RO in the Y direction toward the longitudinal end of the slider body while bringing the tool into contact with the central portion in the longitudinal direction of the opposing side surface of the leg portion of the slider body, A step of forming the first inclined surface of the second raceway surface by moving the tool in the Y direction and the X direction so as to approach the widthwise end of the slider body as the tool approaches the longitudinal end of the slider body, After reaching the longitudinal end of the slider body, a step of forming a part of the second inclined surface and the third inclined surface by moving the tool in the Z direction, which is characterized by the above.

Advantages of the Invention

[0012] According to the present invention, it is possible to provide a linear guide device that can ensure smooth movement of the ball while alleviating the impact force, regardless of the behavior of the ball entering the raceway surface, and a method for manufacturing the same.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this specification, terms indicating directions (upward, downward, etc.) refer to the respective directions in FIG. 2 unless otherwise specified. Further, the "longitudinal direction" refers to the longitudinal direction of the guide rail or the slider.

[0015] (First Embodiment) FIG. 1 is a perspective view showing a linear guide device according to the first embodiment of the present invention. FIG. 2 is a front view of the slider body of the linear guide device in FIG. 1 as viewed from the longitudinal direction of the guide rail, but the end cap is omitted. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2, but the retainer 4 and the retainer groove 10Ba are omitted. In FIG. 2, a plane passing through the center in the width direction of the slider body 2A and the longitudinal axis of the guide rail 1 is defined as a vertical center plane CP, and a plane orthogonal to the vertical center plane CP and passing through the center line O1 of the straight portion of a pair of rolling paths 13A arranged on both sides with the guide rail 1 interposed therebetween is defined as a horizontal reference plane HP. Further, a plane shifted from the center line O1 of the straight portion of the rolling path 13A toward the first raceway surface side and orthogonal to the horizontal reference plane HP is defined as a vertical reference plane VP. However, the vertical reference plane VP is parallel to the vertical center plane CP and is a plane intersecting the second inclined surface and the third inclined surface described later. Although details will be described later, each component configuration will be described using the vertical reference plane VP and the horizontal reference plane HP corresponding to one of the rolling paths 13A.

[0016] Along a guide rail 1 with a substantially rectangular cross-sectional shape extending linearly, a slider 2 with a substantially U-shaped cross-sectional shape is assembled movably in the longitudinal direction of the guide rail 1. On the ridge portions where the left and right side surfaces 1a, 1a in the width direction of the guide rail 1 and the upper surface 1b intersect, track grooves 10A, 10A each consisting of a concave groove with a substantially 1 / 4 arc-shaped cross-sectional shape are formed along the longitudinal direction.

[0017] Also, on the substantially central portions in the vertical direction of the left and right side surfaces 1a, 1a in the width direction of the guide rail 1, track grooves 10B, 10B each consisting of a concave groove with a substantially semi-circular cross-sectional shape are formed along the longitudinal direction. Further, on the groove bottom portions of the track grooves 10B, 10B, a retainer groove 10Ba (wire groove) for accommodating a part of the retainer 4 and guiding the retainer 4 when the slider 2 moves is formed along the longitudinal direction across both ends of the movement region of the slider 2 (for example, between both ends in the longitudinal direction of the guide rail 1). The cross-sectional shape of the retainer groove 10Ba is, for example, substantially rectangular.

[0018] Also, the slider 2 is composed of a flat body portion 7 facing the upper surface 1b of the guide rail 1 and two leg portions 6, 6 extending downward from both left and right side portions of the body portion 7 and facing the side surface 1a. Since the angle formed by the body portion 7 and the leg portions 6, 6 is substantially a right angle, the cross-sectional shape of the slider 2 is substantially U-shaped. Further, the slider 2 is movably attached to the guide rail 1 so as to sandwich the guide rail 1 between both leg portions 6, 6.

[0019] The slider 2 includes a slider body 2A, and end caps 2B, 2B detachably attached to both ends (both longitudinal ends) of the slider body 2A. Further, on both ends of the slider 2 (the outer longitudinal end faces of the respective end caps 2B), side seals 5, 5 are mounted which are in sliding contact with the outer surfaces (upper surface 1b and side surfaces 1a, 1a) of the guide rail 1 and seal the portion facing the longitudinal end face side of the opening of the gap between the guide rail 1 and the slider 2. Under seals 8, 8 are mounted below the slider 2 to seal the portion facing the lower surface side of the slider 2 of the opening of the gap between the guide rail 1 and the slider 2. These side seals 5, 5 and under seals 8, 8 prevent foreign matter from entering the gap from the outside and prevent the lubricant from leaking from the gap to the outside.

[0020] Further, at the corners and the substantially central portion in the vertical direction on the inner side surfaces of the left and right leg portions 6, 6 of the slider body 2A, there are formed groove portions 11A, 11A, 11B, 11B (hereinafter, 11 may be used as a collective reference sign for these) which are formed of concave grooves having a substantially semi-circular cross-sectional shape facing the track grooves 10A, 10A, 10B, 10B (hereinafter, 10 may be used as a collective reference sign for these) of the guide rail 1. Further, between the track groove 10 of the guide rail 1 and the track groove 11 of the slider 2, rolling passages 13A, 13A, 13B, 13B (hereinafter, 13 may be used as a collective reference sign for these) having a substantially circular cross-section are respectively formed, and these rolling passages extend in the longitudinal direction.

[0021] A plurality of rolling elements 3 (balls) are loaded in the rolling passage 13 while being held by a retainer 4 so as to be freely rotatable. Through the rolling of the rolling elements 3 in the rolling passage 13, the slider 2 is guided by the guide rail 1 and is movable in the longitudinal direction. The retainer 4 is formed of, for example, a wire and holds the rolling elements 3 in order to prevent the rolling elements 3 from falling off the slider 2 before being assembled to the guide rail 1.

[0022] Note that the number of the raceways 10 and 11 provided in the guide rail 1 and the slider 2 is not limited to two rows on one side, and may be, for example, one row or three or more rows on one side as in the second embodiment described later. Further, the cross-sectional shape of the raceways 10 and 11 may be an arc shape formed of a single arc as described above, or may be a substantially V-shaped (Gothic arc-shaped groove) formed by combining two arcs having different centers of curvature.

[0023] Further, the slider 2 is provided with return passages 14A, 14A, 14B, 14B (hereinafter, 14 may be used as a collective reference sign for these) which are through holes having a substantially circular cross-sectional shape penetrating in the longitudinal direction parallel to the rolling passage 13 at the upper and lower portions of the thick portions of the left and right leg portions 6, 6 of the slider body 2A (see FIGS. 2 and 3).

[0024] The end cap 2B is made of, for example, a molded product of a resin material, and has a substantially U-shaped cross-sectional shape similar to that of the slider body 2A. Further, on both left and right sides of the back surface (contact surface with the slider body 2A) of the end cap 2B, direction changing paths 15 having a circular cross-sectional shape and curved in an arc shape are formed in two upper and lower stages (see FIG. 3). When this end cap 2B is attached to the slider body 2A with a fastening member such as a screw, the rolling passage 13 and the return passage 14 are connected by the direction changing path 15. Note that the cross-sectional shape of the direction changing path 15 is schematically shown in FIG. 3.

[0025] The return passages 14 and the direction changing paths 15 at both ends constitute a rolling element conveying path 16 for conveying the rolling elements 3 from the end point to the start point of the rolling passage 13 and circulating them, and a substantially annular circulation path is constituted by the rolling passage 13 and the rolling element conveying path 16 (see FIG. 3). This substantially annular circulation path is formed in two upper and lower stages on both left and right sides with the guide rail 1 interposed therebetween.

[0026] When the slider 2 moves longitudinally along the guide rail 1, the rolling elements 3 loaded in the rolling passage 13 roll in the rolling passage 13 and move in the same direction as the slider 2 with respect to the guide rail 1. When the rolling element 3 reaches the end of the rolling passage 13, it is scooped up from the rolling passage 13 and sent to the direction-changing passage 15. The rolling element 3 that enters the direction-changing passage 15 changes its direction and is introduced into the return passage 14, passes through the return passage 14, reaches the opposite direction-changing passage 15, changes its direction again here, and returns to the starting point of the rolling passage 13. By infinitely repeating the circulation of the rolling element 3 in such a circulation path, the slider 2 moves smoothly along the guide rail 1.

[0027] Figure 4 is a perspective view of the slider body 2A. Figure 5 is an enlarged perspective view showing part V of Figure 4. Figure 6 is a cross-sectional view taken along line VI-VI of Figure 4. Figure 7 is a cross-sectional view taken along line VII-VII of Figure 4. Figure 8 is an enlarged view showing part VIII of Figure 7.

[0028] Referring to the drawings, the end shapes of the raceways 11A and 11B will be described. Hereinafter, the raceway 11A will be described as the upper raceway, and the raceway 11B will be described as the lower raceway. Also, when simply referring to the first raceway surface, it refers to at least one of the first upper raceway surface and the first lower raceway surface to be described later, and when simply referring to the second raceway surface, it refers to at least one of the second upper raceway surface and the second lower raceway surface to be described later.

[0029] In Figure 5, the upper raceway 11A has a first upper raceway surface 11Aa on the central side of the slider body 2A and a second upper raceway surface 11Ab on the end side of the slider body 2A. The first upper raceway surface 11Aa and the second upper raceway surface 11Ab are each bounded by the vertical center line C1 (a virtual line) at the groove bottom. The part above the vertical center line C1 is called the upper flank, and the part below the vertical center line C1 is called the lower flank. The upper flank and the lower flank are symmetrically shaped with respect to the vertical center line C1. The vertical center line C1 and the center line O1 of the straight part of the rolling passage 13A are in the horizontal reference plane HP (Figure 2).

[0030] The first upper track surface 11Aa has a uniform cross-section orthogonal to the longitudinal direction. The center line of the cylindrical space formed by the first upper track surface 11Aa and the track groove 10A of the guide rail 1 is defined as the center line O1 of the straight portion of the rolling passage 13A. In contrast, the second upper track surface 11Ab is formed such that the cross-section orthogonal to the longitudinal direction is partially different.

[0031] The second upper track surface 11Ab has a first upward inclined surface 11Ac extending along the vertical center line C1, a second upward inclined surface 11Ad formed above and in contact with the first upward inclined surface 11Ac, and a third upward inclined surface 11Ae formed below and in contact with the first upward inclined surface 11Ac. The first upward inclined surface 11Ac has a symmetric shape with respect to the vertical center line C1 (horizontal reference plane HP), and the second upward inclined surface 11Ad and the third upward inclined surface 11Ae each have a symmetric shape with respect to the vertical center line C1 (horizontal reference plane HP). Here, when simply referring to the first inclined surface, it refers to at least one of the first upward inclined surface and the first downward inclined surface; when simply referring to the second inclined surface, it refers to at least one of the second upward inclined surface and the second downward inclined surface; and when simply referring to the third inclined surface, it refers to at least one of the third upward inclined surface and the third downward inclined surface.

[0032] As shown in FIG. 5, the first upward inclined surface 11Ac is connected to the first upper track surface 11Aa, but the second upward inclined surface 11Ad and the third upward inclined surface 11Ae are longitudinally spaced apart (not continuous) from the first upper track surface 11Aa. Specifically, the width of the first upward inclined surface 11Ac in the direction orthogonal to the vertical center line C1 is uniform in the vicinity of the first upper track surface 11Aa, and is formed in a tapered shape as viewed in the direction of FIG. 6 so as to gradually narrow from the vicinity of the first upper track surface 11Aa toward the end of the slider body 2A. On the other hand, the second upward inclined surface 11Ad and the third upward inclined surface 11Ae start from a position a predetermined distance away from the first upper track surface 11Aa, and are formed in a substantially triangular shape as viewed in the direction of FIG. 6 so that the width in the direction orthogonal to the vertical center line C1 gradually widens toward the end of the slider body 2A.

[0033] In FIG. 8, the first upward inclined surface 11Ac starts from a position at a distance L1 from the end face (longitudinal end) 2Aa of the slider body 2A and ends at the end face 2Aa. Let the distance L1 be the longitudinal length of the first upward inclined surface 11Ac. When the diameter of the rolling element 3 is Da, it is preferable that L1 = 1.0×Da to 2.0×Da.

[0034] The first upward inclined surface 11Ac has a first crowning shape that separates from the center line O1 of the straight portion of the rolling passage 13A (upward in FIG. 8) as it separates from the first upper raceway surface 11Aa. The first crowning shape is an arc shape with a radius of curvature R1 in the cross section of FIG. 8 including the horizontal reference plane HP. In the cross section of FIG. 8, let the point P1 be the intersection point of the first vertical plane PL1 passing through the point on the first upper raceway surface 11Aa that is farthest from the center line O1 of the straight portion of the rolling passage 13A and the second vertical plane PL2 that intersects the end face 2Aa, and let the point P2 be the point where the second vertical plane PL2 intersects the first upward inclined surface 11Ac (here, on the intersection line between the end face 2Aa and the first upward inclined surface 11Ac). Then, the distance between the point P1 and the point P2 is defined as the drop amount d1 of the first crowning.

[0035] FIG. 9 is an enlarged view showing a portion IX of FIG. 6, and shows a cross section including the vertical reference plane VP (that is, the center line O1 of the straight portion is shifted in the direction perpendicular to the paper surface). The second upward inclined surface 11Ad starts from a position at a distance L2 from the end face 2Aa of the slider body 2A and ends at the end face 2Aa. When the longitudinal length of the first upward inclined surface 11Ac is L1, it is preferable that L1 > L2. If L2 is longer than L1, the possibility of inhibiting the function of supporting the load of the upper raceway groove 11A and the crowning function of the first upward inclined surface 11Ac increases, and in addition, the axial cutting amount for the blank (material) of the slider body 2A during processing increases. As a result, there is a concern that the lead time increases due to reducing the radial cutting amount and the load on the tool increases. On the other hand, by setting L1 > L2, the axial cutting amount for the blank of the slider body 2A during processing can be suppressed without disturbing the functions of the upper raceway groove 11A and the first upward inclined surface 11Ac.

[0036] In FIG. 9, the second upper inclined surface 11Ad has a second crowning shape that moves away from the straight portion center line O1 (horizontal reference plane HP) of the rolling path 13A (upward in FIG. 9) as it moves away from the first upper raceway surface 11Aa. The second crowning shape is an arc shape with a radius of curvature R2 in the cross-section of FIG. 9, and it is preferable that R2 < R1.

[0037] In the cross-section of FIG. 9, let the point where the first horizontal plane PM1 passing through the point on the first upper raceway surface 11Aa that is farthest from the straight portion center line O1 of the rolling path 13A intersects the second vertical plane PL2 that intersects the end face 2Aa be P3, and let the point where the second vertical plane PL2 intersects the second upper inclined surface 11Ad (here, on the intersection line of the end face 2Aa and the second upper inclined surface 11Ad) be P4. Then, the distance between point P3 and point P4 is defined as the drop amount d2 of the second crowning. The drop amount d2 of the second crowning can be determined according to the maximum eccentricity e of the rolling element 3 described later, and it is preferable that d2 ≈ d1.

[0038] Here, if half of the inner diameter of the rolling path 13A is r, and the distance between the point P2 on the first upper inclined surface 11Ac and the straight portion center line O1 is D1 (FIG. 8), then D1 can be expressed as D1 = d1 + r. Also, if the distance between the point P4 on the second upper inclined surface 11Ad and the horizontal reference plane HP including the straight portion center line O1 is D2 (FIG. 9), then D2 can be expressed as D2 = d2 + r.

[0039] Regarding the shape of the third upper inclined surface 11Ae, since it is the same as the shape of the second upper inclined surface 11Ad except that it is a symmetric shape with respect to the vertical center line C1, the description thereof is omitted.

[0040] Also, in FIG. 5, the lower raceway groove 11B has a first lower raceway surface 11Ba on the central side of the slider body 2A and a second lower raceway surface 11Bb on the end side of the slider body 2A in parallel with the upper raceway groove 11A. The first lower raceway surface 11Ba and the second lower raceway surface 11Bb are each bounded by the vertical center line C2 (a virtual line) at the groove bottom. The part above the vertical center line C2 is called the upper flank, and the part below the vertical center line C2 is called the lower flank. The upper flank and the lower flank are symmetric shapes with respect to the vertical center line C2.

[0041] The first lower raceway surface 11Ba has a uniform cross-section orthogonal to the longitudinal direction. In contrast, the second lower raceway surface 11Bb is formed such that the cross-section orthogonal to the longitudinal direction is partially different.

[0042] The second lower raceway surface 11Bb has a first downward inclined surface 11Bc extending along the vertical center line C2, a second downward inclined surface 11Bd formed above the first downward inclined surface 11Bc, and a third downward inclined surface 11Be formed below the first downward inclined surface 11Bc. The second downward inclined surface 11Bd and the third downward inclined surface 11Be are symmetrically shaped with respect to the vertical center line C2. Since the lower raceway groove 11B has the same configuration as the upper raceway groove 11A, its description is omitted. Further, since the shape of the other end side of the upper raceway groove 11A and the lower raceway groove 11B is the same as described above, its description is omitted.

[0043] (Operation and Effect of the Present Embodiment) FIG. 10 is a schematic diagram showing a cross-section similar to FIG. 8 according to a comparative example together with rolling elements. FIG. 11 is a schematic diagram showing a cross-section similar to FIG. 9 according to the present embodiment together with rolling elements. FIG. 12 is a schematic diagram showing an enlarged view of part XII of FIG. 6 according to the present embodiment together with rolling elements. Here, the rolling path 13A will be described as an example, but the same applies to the rolling path 13B.

[0044] For the present embodiment, the slider body of the comparative example does not have a second raceway surface, and the cylindrical first upper raceway surface 11Aa directly intersects the end face 2Aa. The configurations of the other comparative examples are the same as those of the present embodiment.

[0045] For example, due to the influence of centrifugal force, vibration, etc. when passing through the turning path 15 (see FIG. 3) in the end cap 2B, the center of the rolling element 3 may deviate from the center line O1 of the straight portion of the rolling path 13A and enter from the turning path 15 into the rolling path 13A in a deviated state. At this time, the amount of deviation between the center of the rolling element 3 and the center line O1 of the straight portion of the rolling path 13A is defined as the eccentricity e. Since the diameter of the rolling element 3 is slightly smaller than the diameter of the rolling path 13A, when the eccentricity e is smaller than 1 / 2 of the diameter difference (diameter of the rolling path 13A - diameter of the rolling element 3), the rolling element 3 can smoothly enter the rolling path 13A. However, when the eccentricity e exceeds 1 / 2 of the diameter difference, the rolling element 3 may abut against the entrance direction edge (edge) of the rolling path 13A, which may cause the generation of noise and damage to the rolling element 3.

[0046] On the other hand, according to this embodiment, in the cross section shown in FIG. 11, the first upper inclined surface 11Ac having the drop amount d1 of the first crowning is formed at the entrance direction end of the rolling path 13A. Therefore, even in a state of being eccentric with an eccentricity e exceeding 1 / 2 of the above diameter difference, the rolling element 3 entering from the turning path 15 obliquely abuts against the first upper inclined surface 11Ac having a convex shape with a radius of curvature R1 and then rolls and is guided to the first upper raceway surface 11Aa. Thereby, by suppressing a large change in Hertz stress, the generation of noise and damage to the rolling element 3 can be suppressed, and smooth movement of the rolling element 3 can be ensured.

[0047] On the other hand, also in the cross section shown in FIG. 12, there may be a case where the rolling element 3 eccentric with an eccentricity e exceeding 1 / 2 of the above diameter difference enters. In such a case, only the first upper inclined surface 11Ac may inhibit the smooth entry of the rolling element 3. In contrast, in this embodiment, in the vicinity of the entrance direction end of the second upper raceway surface 11Ab, above and below the first upper inclined surface 11Ac, a second upper inclined surface 11Ad and a third upper inclined surface 11Ae having the drop amount d2 of the second crowning are formed.

[0048] Therefore, even when the rolling element 3 that is eccentric with a relatively large eccentricity e in the vertical direction enters, it obliquely contacts the second upward inclined surface 11Ad or the third upward inclined surface 11Ae having a convex shape with a radius of curvature R2 and then rolls, and thereafter is guided from the first upward inclined surface 11Ac to the first upper raceway surface 11Aa. Thereby, the collision force to the slider body 2A is alleviated, and generation of noise and damage to the rolling element 3 can be suppressed.

[0049] The lower raceway groove 11B also has the same configuration as the upper raceway groove 11A, and thus exhibits the same effect.

[0050] (Processing method of the first upper raceway surface and the second upper raceway surface) Next, the processing method of the first upper raceway surface 11Aa and the second upper raceway surface 11Ab will be described. FIGS. 13 to 15 are schematic views showing a part of the end face 2Aa of the blank (material) of the slider body 2A viewed from the longitudinal direction and a grinding tool TL. FIG. 14 is a schematic view showing the cross section of FIG. 6 and the grinding tool TL. FIG. 15 is a schematic view showing a locus of a part of the grinding tool TL.

[0051] In FIGS. 13 to 15, the longitudinal direction of the slider body 2A is defined as the Y direction, the width direction of the slider body 2A is defined as the X direction, and the vertical direction is defined as the Z direction.

[0052] The grinding tool TL includes a pair of parallel annular grinding wheels TL2, TL2 and a cylindrical portion TL1 that coaxially holds the grinding wheels TL2, TL2. When the grinding tool TL is cut by a plane passing through the center line RO of the grinding tool TL, the grinding wheels TL2, TL2 have an outer peripheral surface having the same semi-circular shape as the upper raceway groove 11A and the lower raceway groove 11B.

[0053] When grinding the first upper track surface 11Aa and the first lower track surface 11Ba, first, in the blank of the slider body 2A, grooves similar to the first upper track surface 11Aa and the first lower track surface 11Ba are formed by cutting or the like. Then, while aligning the center line RO of the grinding tool TL in the Z direction, the grinding tool TL rotating around the center line RO is translated in the X direction toward the inside of the leg portion 6, and after starting the grinding of the inner surface of the groove with the outer peripheral surfaces of the grindstones TL2, TL2, the grinding tool TL is moved in the Y direction. Thereby, the first upper track surface 11Aa and the first lower track surface 11Ba are formed.

[0054] After forming the first upper track surface 11Aa and the first lower track surface 11Ba, the first upper inclined surface 11Ac and the first lower inclined surface 11Bc are machined and formed. Specifically, while rotating the grinding tool TL, as it approaches the end face 2Aa of the slider body 2A, the grinding tool TL is translated in the Y direction and the X direction so that the center line RO of the grinding tool TL approaches the widthwise end of the blank of the slider body 2A. At this time, it is preferable that the locus of the center line RO of the grinding tool TL coincides with an arc shape having a radius of curvature R1 shown in FIG. 8. Thereby, the first upper inclined surface 11Ac shown in FIG. 8 is ground, and at the same time, the first lower inclined surface 11Bc is ground.

[0055] Thereafter, the second upper inclined surface 11Ad and the second lower inclined surface 11Bd are machined and formed. Specifically, from an initial position where the grinding tool TL intersects the end face 2Aa, while rotating the grinding tool TL around the center line RO, as shown in FIG. 15(a), the grinding tool TL is translated upward in the Z direction. Then, as shown in FIG. 15(b), as it approaches the first upper track surface 11Aa and the first lower track surface 11Ba from the end face 2Aa of the slider body 2A, the grinding tool TL is translated in the Y direction and the X direction so that the center line RO of the grinding tool TL moves away from the widthwise end of the blank of the slider body 2A. When reaching a position at a distance L2 from the end face 2Aa, the grindstones TL2, TL2 are separated from the blank of the slider body 2A. At this time, it is preferable that the locus of the center line RO of the grinding tool TL coincides with an arc shape having a radius of curvature R2 shown in FIG. 9. Thereby, the second upper inclined surface 11Ad shown in FIG. 9 is ground, and at the same time, the second lower inclined surface 11Bd is ground.

[0056] Furthermore, a third upper inclined surface 11Ae and a third lower inclined surface 11Be are machined and formed. Specifically, the grinding tool TL is returned to the initial position and rotated around the center line RO. Then, as shown in FIG. 15(a), the grinding tool TL is translated downward in the Z direction. After that, as shown in FIG. 15(b), as the grinding tool TL approaches the first upper raceway surface 11Aa and the first lower raceway surface 11Ba from the end surface 2Aa of the slider body 2A, the center line RO of the grinding tool TL is moved away from the first upper raceway surface 11Aa and the first lower raceway surface 11Ba by translating the grinding tool TL in the Y direction and the X direction. When reaching a position at a distance L2 from the end surface 2Aa, the grinding wheels TL2, TL2 are separated from the blank of the slider body 2A. At this time, the locus of the center line RO of the grinding tool TL preferably coincides with an arc shape having a radius of curvature R2 shown in FIG. 9. Thereby, the third upper inclined surface 11Ae shown in FIG. 9 is machined, and at the same time, the third lower inclined surface 11Be is machined. Further, since the machining of the other end sides of the upper raceway groove 11A and the lower raceway groove 11B is the same as described above, the description thereof is omitted.

[0057] In the present embodiment, the upper raceway groove 11A and the lower raceway groove 11B are machined and formed simultaneously, but they may be machined and formed separately.

[0058] According to the present embodiment, by forming the second crowning shape in the raceway grooves 11A, 11B of the slider body 2A, a sufficient drop amount can be ensured in a direction different from the first crowning shape. Therefore, even when the rolling element 3 eccentrically enters the rolling passages 13A, 13B, smooth movement can be ensured.

[0059] In addition, since it is possible to suppress the rolling element 3 from colliding with the edge at the end of the rolling passages 13A, 13B, an increase in the collision pressure when the rolling element 3 enters the rolling passages 13A, 13B can be suppressed.

[0060] Furthermore, the second upper inclined surface 11Ad and the second lower inclined surface 11Bd, and the third upper inclined surface 11Ae and the third lower inclined surface 11Be can be processed and formed by adding their moving directions using a grinding tool TL that forms the first upper inclined surface 11Ac and the first lower inclined surface 11Bc. Therefore, the workability is good and the cost is not increased significantly.

[0061] Also, by forming a second crowning shape with a larger clearance amount from the center lines of the rolling paths 13A and 13B, the allowable range of the mounting error of the circulating component corresponding to the eccentricity of the rolling element 3 is widened. Therefore, the machining error of the surface serving as the positioning reference for the circulating component provided on the slider body 2A can be tolerated, and the cost can be reduced.

[0062] (Modification Example 1) FIG. 16 is a cross-sectional view similar to FIG. 8 showing Modification Example 1 of the first embodiment, and FIG. 17 is a cross-sectional view similar to FIG. 9 showing Modification Example 1 of the first embodiment, showing a cross-section including the vertical reference plane VP.

[0063] The upper raceway groove 11A in Modification Example 1 has a first upper raceway surface 11Aa on the central side of the slider body 2A and a second upper raceway surface 11Ab' on the end side of the slider body 2A.

[0064] The second upper raceway surface 11Ab' has a first upper inclined surface 11Ac', a second upper inclined surface 11Ad' formed upward on the end side of the first upper inclined surface 11Ac', and a third upper inclined surface 11Ae' formed downward on the end side of the first upper inclined surface 11Ac'.

[0065] The first upper inclined surface 11Ac' has a first tapered shape (a crowning shape with a linear cross-section) that moves away from the center line O1 of the straight portion of the rolling path 13A (upward in FIG. 16) as it moves away from the first upper raceway surface 11Aa. The first upper inclined surface 11Ac' has a drop amount d1 of the first crowning.

[0066] The second upward inclined surface 11Ad' starts from a position at a distance L2 from the end face 2Aa of the slider body 2A and ends at the end face 2Aa. If the longitudinal length of the first upward inclined surface 11Ac' is the distance L1, then L1 > L2.

[0067] The second upward inclined surface 11Ad' has a second tapered shape (a crowning shape with a linear cross-section) that moves away from the center line O1 (horizontal reference plane HP) of the straight portion of the rolling passage 13A (upward in FIG. 17) as it moves away from the first upper track surface 11Aa. The second upward inclined surface 11Ad' also has a second crowning drop d2. It is preferable that d2 ≒ d1.

[0068] That is, the surface (the intersection with the horizontal reference plane HP) of the first upward inclined surface 11Ac' in the cross-section of FIG. 16 is linear, and the surfaces (the intersections with the vertical reference plane VP) of the second upward inclined surface 11Ad' and the third upward inclined surface 11Ae' in the cross-section of FIG. 17 are also linear.

[0069] Regarding the shape of the third upward inclined surface 11Ae', except for being a symmetric shape, it is the same as the shape of the second upward inclined surface 11Ad'. Also, since the shape of the second lower track surface (not shown) is the same as that of the second upper track surface 11Ab', the descriptions of these are omitted. Also, regarding the configurations other than the second upper track surface 11Ab' and the second lower track surface, since they are the same as those in the first embodiment, duplicate descriptions are omitted.

[0070] (Modification 2) FIG. 18 is a cross-sectional view similar to FIG. 9 showing Modification 2 of the first embodiment, showing a cross-section including the vertical reference plane VP. The upper track groove 11A in Modification 2 has a first upper track surface 11Aa on the central side of the slider body 2A and a second upper track surface 11Ab'' on the end side of the slider body 2A.

[0071] The second upper track surface 11Ab” has a first upper inclined surface 11Ac, a second upper inclined surface 11Ad formed upward on the end side of the first upper inclined surface 11Ac, and a third upper inclined surface 11Ae formed downward on the end side of the first upper inclined surface 11Ac. The second upper inclined surface 11Ad and the third upper inclined surface 11Ae extend from a position separated from the first upper track surface 11Aa to the vicinity of the end surface 2Aa of the slider body 2A.

[0072] Furthermore, between the second upper inclined surface 11Ad and the end surface 2Aa of the slider body 2A, a tapered fourth upper inclined surface 11Af that separates from the center line O1 of the straight portion of the rolling passage 13A (upward in FIG. 18) as it separates from the first upper track surface 11Aa is formed connected to the second upper inclined surface 11Ad. Also, between the third upper inclined surface 11Ae and the end surface 2Aa of the slider body 2A, a tapered fifth upper inclined surface 11Ag that separates from the center line O1 of the straight portion of the rolling passage 13A (downward in FIG. 18) as it separates from the first upper track surface 11Aa is formed connected to the third upper inclined surface 11Ae. Here, when simply referring to the fourth inclined surface, it refers to at least one of the fourth upper inclined surface and the fourth lower inclined surface, and when simply referring to the fifth inclined surface, it refers to at least one of the fifth upper inclined surface and the fifth lower inclined surface.

[0073] In the cross section of FIG. 18, the surfaces (intersection portions with the vertical reference plane VP) of the fourth upper inclined surface 11Af and the fifth upper inclined surface 11Ag are linear.

[0074] In the cross section of FIG. 18, the inclination angle θ of the surfaces (intersection portions with the vertical reference plane VP) of the fourth upper inclined surface 11Af and the fifth upper inclined surface 11Ag with respect to the center line O1 of the straight portion of the rolling passage 13A is preferably 15 degrees to 50 degrees, and more preferably 45 degrees.

[0075] According to this modification, the distance between the intersection point P5 of the end face 2Aa of the slider body 2A and the fourth upward inclined surface 11Af and the fifth upward inclined surface 11Ag, and the intersection point P4 of the end face 2Aa and the second upward inclined surface 11Ad and the third upward inclined surface 11Ae in the case where the fourth upward inclined surface 11Af and the fifth upward inclined surface 11Ag are not present (the first embodiment shown by the dashed line in FIG. 18) is d3. Therefore, by forming the fourth upward inclined surface 11Af and the fifth upward inclined surface 11Ag between the ends of the second upward inclined surface 11Ad and the third upward inclined surface 11Ae and the end face 2Aa of the slider body 2A, the further drop amount d3 can be ensured, and thereby, even when the eccentricity e of the rolling element 3 increases, the rolling element 3 can smoothly enter the return path. Regarding the configuration other than the fourth upward inclined surface 11Af and the fifth upward inclined surface 11Ag, since it is the same as that of the first embodiment, the overlapping description is omitted.

[0076] (Second Embodiment) FIG. 19 is a cross-sectional view similar to FIG. 2 of the slider body 2A' according to the second embodiment. In the present embodiment, it only has the raceways 11A, 11A of the rolling paths 13A, 13A, and accordingly, the shape of the guide rail (not shown) is also different. Regarding the other configurations, since it is the same as that of the first embodiment including the shape of the raceways 11A, 11A, the overlapping description is omitted.

[0077] The present invention is not limited to the above embodiments, and it is also within the scope of the present invention for those skilled in the art to combine each configuration of the embodiments with each other, make changes and applications based on the description in the specification and well-known technologies, and these are included in the scope for which protection is sought.

Explanation of Reference Numerals

[0078] 1 Guide rail 2 Slider 2A Slider body 2B End cap 3 Rolling element 4 Retainer 10A, 10B Raceway 11A, 11A Raceway 13A, 13B Rolling path Return passages 14A and 14B Diversion path 15

Claims

1. A guide rail, A slider arranged to move relative to the guide rail in the longitudinal direction, A linear guide device comprising a plurality of rolling elements arranged to roll freely along a rolling passage formed between the guide rail and the slider, The slider, A slider body having a raceway groove facing the raceway groove of the guide rail to form a rolling passage for the rolling elements and a return passage for the rolling elements, An end cap having a direction-changing passage connecting the return passage and the rolling passage, The raceway groove of the slider body has a first raceway surface on the central portion side of the rolling passage and a second raceway surface on the end portion side of the rolling passage, The second raceway surface has a first inclined surface extending from the first raceway surface to the end face of the slider body, and a second inclined surface and a third inclined surface extending to the end face of the slider body or the vicinity thereof without being continuous with the first raceway surface, When a plane passing through the center in the width direction of the slider body and the longitudinal axis of the guide rail is defined as a vertical center plane CP, a plane perpendicular to the vertical center plane CP and passing through the center line of the straight portion of the rolling passage is defined as a horizontal reference plane HP, and a plane parallel to the vertical center plane CP and intersecting the second inclined surface and the third inclined surface is defined as a vertical reference plane VP, A point P2 on the first inclined surface farthest from the vertical reference plane VP is spaced apart from the vertical reference plane VP more than a point P1 on the first raceway surface farthest from the vertical reference plane VP, and points P4 on the second inclined surface and the third inclined surface farthest from the horizontal reference plane HP are spaced apart from the horizontal reference plane HP more than a point P3 on the first raceway surface farthest from the horizontal reference plane HP, A linear guide device characterized by the above.

2. The point P2 on the first inclined surface farthest from the vertical reference plane VP is located on the intersection line between the end face of the slider body and the first inclined surface, The first inclined surface is spaced apart from the vertical reference plane VP as it approaches the end face of the slider body, The linear guide device according to claim 1, characterized by the above.

3. The points P4 on the second inclined surface and the third inclined surface farthest from the horizontal reference plane HP are located at the intersection points between the end face of the slider body and the second inclined surface and the third inclined surface, The second inclined surface and the third inclined surface are spaced apart from the horizontal reference plane HP as they approach the end face of the slider body, The linear guide device according to claim 2, characterized in that...

4. The cross-sectional shape of the first inclined surface obtained by cutting along the horizontal reference plane HP has an arc shape with a radius of curvature R1, and the cross-sectional shapes of the second inclined surface and the third inclined surface obtained by cutting along the vertical reference plane VP have an arc shape with a radius of curvature R2, where R2 < R1. The linear guide device according to claim 3, characterized in that...

5. The intersection of the surface of the first inclined surface intersecting the horizontal reference plane HP is linear, and the intersections of the surfaces of the second inclined surface and the third inclined surface intersecting the vertical reference plane VP are linear. The linear guide device according to claim 3, characterized in that...

6. A fourth inclined surface is formed between the end surface of the slider body and the second inclined surface, and a fifth inclined surface is formed between the end surface of the slider body and the third inclined surface. The intersection of the surfaces of the fourth inclined surface and the fifth inclined surface intersecting the vertical reference plane VP is linear. The linear guide device according to claim 1, characterized in that...

7. The inclination angle θ between the intersection of the surfaces of the fourth inclined surface and the fifth inclined surface intersecting the vertical reference plane VP and the vertical reference plane VP is 15 degrees to 50 degrees. The linear guide device according to claim 6, characterized in that...

8. The second inclined surface and the third inclined surface have a symmetrical shape with the horizontal reference plane HP interposed therebetween. The linear guide device according to any one of claims 1 to 7, characterized in that...

9. A guide rail, A slider arranged to move relative to the guide rail in the longitudinal direction, A method for manufacturing a linear guide device including a plurality of rolling elements rollably arranged along a rolling passage formed between the guide rail and the slider, The slider includes A slider body having a raceway groove facing the raceway groove of the guide rail to form a rolling passage for the rolling element and a return passage for the rolling element, An end cap having a direction-changing passage connecting the return passage and the rolling passage, The raceway groove of the slider body has a first raceway surface on the central side of the rolling passage and a second raceway surface on the end side of the rolling passage. The second raceway surface has a first inclined surface extending from the first raceway surface to the end surface of the slider body, and a second inclined surface and a third inclined surface extending to the end surface of the slider body or its vicinity without being continuous with the first raceway surface. The slider body has a body portion and a pair of leg portions disposed at both ends in the width direction of the body portion. When the width direction of the slider body is the X direction, the longitudinal direction of the slider body is the Y direction, and the direction orthogonal to the X direction and the Y direction is the Z direction, a step of forming the first raceway surface by bringing a tool having an annular grinding wheel and rotating around a rotation axis RO into contact with a central portion in the longitudinal direction of the opposing side surfaces of the leg portions of the slider body and moving the tool in the Y direction toward an end portion in the longitudinal direction of the slider body; a step of forming the first inclined surface of the second raceway surface by moving the tool in the Y direction and the X direction so as to approach the widthwise end portion of the slider body as the tool approaches the longitudinal end portion of the slider body; a step of forming a part of the second inclined surface and the third inclined surface by moving the tool in the Z direction after the tool reaches the longitudinal end portion of the slider body. A method for manufacturing a linear guide device, characterized in that.

10. After moving the tool in the Z direction, the tool is moved in the X direction and the Y direction toward the central portion of the slider body so as to move away from the widthwise end portion of the slider body as it moves away from the longitudinal end portion of the slider body, thereby forming the remainder of the second inclined surface and the third inclined surface. A method for manufacturing a linear guide device according to claim 9, characterized in that.

11. The tool coaxially has a pair of the annular grinding wheels. A method for manufacturing a linear guide device according to claim 9 or 10, characterized in that.

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