JP4003220B2 - Linear guide device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an improvement of a ball holder in a relatively small linear guide device used for manufacturing equipment for electronic parts such as hydraulic equipment, pneumatic equipment, semiconductors, peripheral equipment for computers, measuring equipment, and the like.
[0002]
[Prior art]
As shown in FIGS. 9 and 10, in the linear guide device, a slider (also referred to as a bearing) 102 attached to a long guide rail 101 extending in the axial direction is guided by the guide rail 101 and smooth in the axial direction. Relative linear movement. On both side surfaces of the guide rail 101, one or two rows of substantially semicircular arc-shaped ball rolling grooves 103 are formed with a narrow relief groove at the bottom of the groove.
[0003]
On the other hand, the reverse concave slider 102 straddling the guide rail 101 has a ball rolling groove 104 opposed to the ball rolling groove 103 of the guide rail 101 on the inner side surface of both sleeve portions, and the inner thickness of the sleeve portion at the back. The ball return path 105 formed of an axial through hole parallel to the ball rolling groove 104 is connected to the end cap 102B attached to both ends in the axial direction, and the ball return path 105 and the ball rolling groove 104 are communicated with each other. Each has a semi-doughnut-shaped curved path 106.
[0004]
Then, an infinite circulation path of the ball by the load ball rolling path 107 formed by the ball rolling groove 103 of the guide rail 101 and the ball rolling groove 104 of the slider 102, both the front and rear curved paths 106, and the ball return path 105. 108, a large number of balls (steel balls) 109 are inserted so as to be able to roll, and infinite circulation while the balls 109 roll as the slider 102 moves relative to each other.
[0005]
When the linear guide device is assembled, the ball is loaded in advance on the infinite circulation path of the ball of the slider 102, and then the slider 102 is assembled to the guide rail 101. Before assembling to the guide rail 101, it is necessary to prevent the balls in the ball rolling groove of the slider from falling off. For this reason, the ball holder 110 is attached to the slider 102 to hold the ball 109 in the ball rolling groove 104. ing. When the slider 102 is assembled to the guide rail 101 while holding the ball 109 with the ball holder 110, the straight portion of the ball holder 110 is stored in the relief groove 111 at the bottom of the ball rolling groove 103 of the guide rail 101. Therefore, it does not hinder the rolling of the ball.
[0006]
As a ball holder of the linear guide device, for example, there is one shown in Japanese Utility Model Publication No. 62-8427. As shown in FIG. 10, the ball holder 110 of this example includes a straight portion 112 that fits in the clearance groove 111 of the ball rolling groove 103 of the guide rail 101 and a half formed continuously at both ends of the straight portion 112. A wire rod holder having an arcuate curved portion 113, and a semicircular arcuate curved portion 113 in a concave groove 116 provided on an inner wall surface of a semi-doughnut-shaped curved path 106 of an end cap 102B attached to the slider 102. Are fitted to the slider 102.
[0007]
However, in the case of the above configuration, a slight error is inevitable between the length of the linear portion 112 of the ball holder 110 and the length of the slider body 102A in the axial direction. Therefore, in order to absorb this error, the ball holder The concave groove 116 provided on the inner wall surface of the semi-doughnut-shaped curved path 106 of the end cap 102B with which the curved portion 113 is engaged is slightly larger than the outer radius of the ball holder 110, so that a minute gap is formed between the holder and the holder. I am trying to provide it. For this reason, play will occur in the mounted ball holder, and in the case of a small linear guide device, this play may cause the ball to drop or cause interference between the ball holder and the guide rail. become.
[0008]
Therefore, the invention of “Ball holder of linear guide device” in Japanese Patent Laid-Open No. 8-93762 improves the end cap portion of the slider and the shape of the ball holder. In other words, a semi-doughnut-shaped curved path that allows the ball return path and the ball rolling path to communicate with each other is formed on the joint surface of the end cap with the slider body, and the curved path is provided on the surface opposite to the joint surface of the end cap. An arc-shaped outer peripheral groove is provided. In this groove, a ball holder having a linear part and a locking part formed in an arc shape at both ends thereof is locked, and the locking part is restrained by a protrusion formed on the side wall in the groove. Yes.
[0009]
[Problems to be solved by the invention]
However, in the configuration disclosed in JP-A-8-93762, the arc center of the arc-shaped outer peripheral groove and the arc center of the ball holder are located on the same center line, and the sizes of both arcs are substantially the same. This is the structure. In the case of this structure, especially when there is a processing error (dimension variation) in the longitudinal dimensions of the bearing body or ball holder, or when the dimensions of the arcs of the two differ, the joint between the end cap and the ball holder It is conceivable that a gap is formed in the ball holder, the ball holder is loose, or the ball holder is displaced in the direction in which the ball is detached from the end cap, the mounting posture becomes unstable, and the holding force of the ball is reduced.
[0010]
Therefore, an object of the present invention is to prevent the mounting posture of the ball holder from becoming unstable due to a slight processing error between the end cap and the ball holder.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a linear guide device according to the present invention includes a guide rail having an axial ball rolling groove formed on a side surface, and a ball rolling groove facing the ball rolling groove of the guide rail. And a slider straddling the guide rail so as to be axially movable relative to the guide rail. The slider has a ball return path formed of an axial through hole parallel to the ball rolling groove on the inner surface. A slider main body having a sleeve thickness, and an end cap having a semi-doughnut-shaped curved path that is joined to both end faces of the slider main body and allows the ball return passage and the ball rolling groove to communicate with each other on the back face. An infinite circulation path is formed symmetrically by the load ball rolling path formed by the ball rolling groove of the guide rail and the ball rolling groove of the slider, the ball return path, and the curved path, Infinite circulation A linear guide device is provided with a ball holder that is loaded with a large number of balls and is mounted on the slider to prevent the balls from falling off. An arc-shaped outer peripheral groove corresponding to the curved path, the ball holder is made of a wire, and has a linear portion and a locking portion formed at both ends of the linear portion and locked to the outer peripheral groove. The locking portion is formed in a substantially arc shape, and on the distal end side of the locking portion formed in an arc shape, a relatively large clamping force (locking force) is generated with respect to the outer peripheral groove. It is formed as follows.
[0012]
Preferably, in order to obtain the clamping force, on the base side of the locking part, the curvature is larger than the curvature of the outer peripheral groove of the end cap on the tip side of the arc-shaped locking part of the ball holder. The curvature is formed so as to be smaller than the curvature of the outer peripheral groove of the end cap. Alternatively, the arc of the ball holder locking portion is a single arc, and the center of the arc is formed so as to be shifted in the direction approaching the guide rail with respect to the center of the arc of the end cap outer peripheral groove.
[0013]
According to the above configuration, a force for deeply engaging the end cap is generated in the engaging portion of the ball holder. For this reason, even if there is an outer peripheral groove machining error, the engagement is ensured and the influence of the machining error is reduced. Further, the mounting posture of the ball holder is stabilized, the ball holding force is improved, and the workability at the time of loading the ball is improved. In addition, even if the bearing is removed from the rail when the linear guide is handled by the user, and there is an impact, there is less concern about the ball falling off.
[0014]
[Embodiment]
The present invention will be described below with reference to the drawings. 1 to 8 show an example of an embodiment of the present invention. FIG. 1 is a plan view of a small linear guide device, FIG. 2 is a side view thereof, and FIG. 3 is an example of a first ball holder. FIG. 4 is a side view of FIG. 3, FIG. 5 is a plan view showing an example of a second ball holder, and FIGS. 6 to 8 illustrate a ball holder mounting structure. FIG. 7 is a sectional view in the VI-VI direction of FIG. 6 and FIG. 8 is a diagram for explaining the shape in the VII direction of FIG. FIG. Corresponding parts are denoted by the same reference numerals in the drawings.
[0015]
First, the overall configuration will be described. As shown in FIGS. 1 and 2, the prismatic guide rail 11 of the small linear guide device of this embodiment has a ball rolling groove having a substantially semi-circular cross section with one strip extending in the axial direction on both side surfaces thereof. 12 are symmetrically provided. A narrow axial relief groove 13 is formed on the groove bottom of each groove over the entire length of the groove. The slider 14 has a substantially U-shaped cross section, and has ball rolling grooves 16 facing the ball rolling grooves 12 of the guide rails on the inner side surfaces of both sleeve portions 15, respectively. It is straddled so that it can move in the axial direction. The slider 14 includes a slider main body 14A and end caps 14B joined to both front and rear end faces.
[0016]
As shown in FIG. 6, the end cap 14 </ b> B is formed with a groove 22 for locking the ball holder 30. The end cap 14B is formed by plastic molding. A side seal 35 is attached to the surface 14Ba of the end cap 14B. The guide rail 11 is formed with a mounting bolt hole 36 for attaching the guide rail to the base. A mounting bolt hole 37 for attaching a table or the like to the slider 14 is formed on the upper surface of the slider 14.
[0017]
As shown in the sectional view of the sleeve portion 15 in FIG. 7, the slider main body 14A has a ball return groove 17 formed of an axial through hole parallel to the ball rolling groove 16 on the inner surface. It is formed within the thickness of the portion 15.
[0018]
On the other hand, the end cap 14B has a semi-doughnut-shaped curved path 18 that allows the ball rolling groove 16 and the ball return path 17 to communicate with a back surface 14Bb that is a joint surface with the slider body 14A, and an opening of the curved path 18. A ball scooping projection 19 is formed which projects from the end into the ball rolling groove 12 of the guide rail and scoops up the ball. Further, on the front surface 14Ba of the end cap 14B, an outer peripheral groove 22 having an outwardly convex arc-shaped bottom surface 21 and deepened on both sides is formed so as to correspond to the curved path 18 on the back surface. As shown in FIG. 2, a protrusion (holding pinch protrusion) 23 protruding so as to slightly narrow the groove width 22w of the outer peripheral groove 22 is provided on a part of the groove wall surface.
[0019]
As shown in FIG. 7, a load ball rolling path 24 is formed by the ball rolling groove 12 of the guide rail 11 and the ball rolling groove 16 of the slider body 14 </ b> A opposed to the ball rolling groove 12. The load ball rolling path 24, the ball return path 17, and the bay road 18 constitute a ball infinite circulation path. This ball infinite circulation path is provided symmetrically on both sides with the guide rail 11 in between, and a large number of balls 25 are loaded in each infinite circulation path. Then, in a state before being assembled to the guide rail 11, the balls 25 are held by a ball holder 30 attached to the slider 14 so that the balls 25 do not fall out of the ball rolling groove 16 of the slider.
[0020]
As shown in FIGS. 3 and 4, the ball holder 30 is formed by molding a metal wire having a circular cross section, and is accommodated in the clearance groove 13 of the ball rolling groove 12 of the guide rail 11. The linear part 31 and the circular-arc-shaped latching | locking part 32 formed in the both ends are provided. The engaging portion 32 is engaged with the outer peripheral groove 22 formed in the end cap, and the ball holder 30 is attached to the end cap 14B.
[0021]
FIG. 3 shows the first embodiment of the present invention, in which the center of the arc (radius R2) of the arc-shaped locking portion 32 of the ball holder and the arc (radius R) of the outer peripheral groove bottom 21 of the end cap are shown. Is set so as to be shifted by d1 in the vertical direction of FIG. The arc radius R of the end cap is formed to be equal to or slightly smaller than the arc radius R2 of the locking portion 32. According to this configuration, when the ball holder 30 is attached to the outer peripheral groove bottom portion 21, a larger clamping force can be obtained on the tip side than on the base side.
[0022]
FIG. 5 shows a second embodiment of the present invention and shows another configuration example of the ball holder 30. The side surface is the same as that of FIG. In this example, the tip end side 32a and the base side 32b of the arc-shaped locking portion 32 of the ball holder are formed with two different arc radii. If the arc radius of the tip end side 32a is R1, the arc radius of the base side 32b is R2, and the arc radius of the outer peripheral groove bottom 21 of the end cap is R (not shown), the centers of the arc radii are on the same line. The radius relationship is formed such that R1 <R <R2. Also with this configuration, when the ball holder 30 is attached to the outer peripheral groove bottom portion 21, a greater clamping force can be obtained on the tip side than on the base side.
[0023]
Next, the operation of the embodiment having the above configuration will be described. As shown in FIG. 7, the ball holder 30 has an end portion of the ball holder on the bottom portion 21 of the outer peripheral groove 22 formed on the surface 14Ba of the end cap 14B joined to the end portion of the main body 14A of the slider 14 with a bolt. The locking portion 32 is locked and mounted. As described above, the curvature of the distal end side 32a of the locking portion 32 of the ball holder 30 according to the second embodiment is relatively larger than the curvature of the outer peripheral groove bottom portion 21, and the curvature of the base side 32b is relative. Is set smaller than the curvature of the outer circumferential groove bottom 21, the tip side is in close contact with the groove bottom, and the base side is non-contact or light contact. Then, a force is generated on the distal end side 32a of the engaging portion 32 so that the engaging portion 32 sandwiches the end cap, particularly at the distal end portion thereof. Moreover, since it is non-contact or light contact with the base side groove bottom, no force acts on the ball holder in a direction away from the rolling path of the load ball. As a result, in the example of FIG. 7, the distal end side 32 a of the locking portion 32 acts so as to deeply enter the groove bottom portion 21 by the locking force and is in close contact with the groove bottom portion 21. Therefore, the ball holder is attached to the end cap without play, and the ball holding force is improved. Further, the second embodiment is also configured by slightly shifting the center of the arc of the locking portion 32 of the ball holder according to the first embodiment toward the guide rail 11 with respect to the center of the arc of the outer peripheral groove bottom 21 of the end cap. As in the first embodiment, the distal end side of the locking portion 32 is in close contact with the outer peripheral groove bottom portion 21, the base side is non-contact or light contact, and the ball holder 30 is attached to the end cap without play, and the ball holding force Will improve. Further, the ball holder 30 is prevented from rattling by being attached between the protrusions (holder-holding protrusions) 23 protruding inward of the groove surface of the outer peripheral groove 22. Therefore, the locking portion 32 is not only restrained in the length direction and width direction of the slider 14, but is also restrained in the vertical direction to prevent it from coming off.
[0024]
After mounting the ball holder 30 in this way, the ball 25 is loaded into the ball rolling groove 16, the ball return path 17, and the curved path 18 of the slider 14. Since the ball 25 loaded in the ball rolling groove 16 is supported by the linear portion 31 of the ball holder 30 and is securely held in the ball rolling groove 16 of the slider 14, it does not fall off.
[0025]
Next, the slider 14 loaded with the balls 25 is assembled to the guide rail 11. At this time, the linear portion 31 of the ball holder 30 is accommodated in the escape groove 13 at the bottom of the ball rolling groove 12 of the guide rail 11 and does not interfere with the guide rail. Thereafter, the slider 14 is moved on the guide rail 11 to check the operability, but the operation can be performed quickly and efficiently. Finally, the side seal 35 is attached to the end cap 14B to obtain a product.
[0026]
In the above-described embodiment, the linear guide device in which the ball rolling grooves 12 and 16 are symmetrically formed one by one has been described. However, the present invention is not limited to this, and this is not the case even when the ball rolling groove has two or more on one side. The ball holder of the invention can be applied.
[0027]
As described above, according to the embodiment of the present invention, the engaging portion of the ball holder acts so as to engage deeply with the end cap itself. Defects due to decrease. Also, operations such as ball loading and subsequent linear guide checking can be performed quickly and efficiently. Moreover, since it becomes difficult for a user to drop | omit a ball | bowl, the working efficiency at the time of handling improves and is preferable.
[0028]
【The invention's effect】
As described above, in the linear guide device of the present invention, the clamping force is concentrated on the tip side of the locking portion of the ball holder, so that the mounting posture is stable, and the processing accuracy of the ball holder and related parts is high. This is preferable because defects due to errors are reduced.
[Brief description of the drawings]
FIG. 1 is a plan view illustrating an embodiment of a linear guide device of the present invention.
FIG. 2 is a side view of the linear guide device shown in FIG.
FIG. 3 is a plan view illustrating a first configuration example of a ball holder.
4 is a side view of the ball holder shown in FIG. 3. FIG.
FIG. 5 is a plan view illustrating a second configuration example of the ball holder.
FIG. 6 is a front view illustrating a ball holder mounting structure of an end cap.
7 is a cross-sectional view in the VI-VI direction of FIG. 6 for explaining a ball holder mounting structure of an end cap.
8 is a partial side view in the VII direction of FIG. 7 for explaining a ball holder mounting structure of an end cap.
FIG. 9 is an overall perspective view showing an example of a conventional linear guide device.
FIG. 10 is a cross-sectional view for explaining a ball circulation path portion and a ball holder mounting portion of a conventional linear guide device.
DESCRIPTION OF SYMBOLS 11 Guide rail 12 Ball rolling groove 13 of guide rail 14 Escape groove 14 Slider 14A Slider main body 14B End cap 15 Slider sleeve 16 Slider ball rolling groove 17 Ball return path 18 Curved path 21 Arc bottom surface of outer peripheral groove 22 outer peripheral groove 23 protrusion 24 of outer peripheral groove load ball rolling path 30 holder 31 linear portion 32 locking portion 32a distal end side 32b base side

Claims (4)

  A guide rail having an axial ball rolling groove formed on the side surface, and a ball rolling groove facing the ball rolling groove of the guide rail on the inner side surface so as to be axially movable on the guide rail. A slider body having a ball return path formed of an axial through hole parallel to the ball rolling groove on the inner side surface in the sleeve thickness, and the slider. An end cap having a semi-doughnut-shaped curved path that is joined to both end faces of the main body and communicates with the ball return passage and the ball rolling groove on the joining face on the back surface, and the ball rolling groove of the guide rail and the slider The load ball rolling path formed by the ball rolling groove, the ball return path and the curved path form an infinite circulation path symmetrically, and a large number of balls are loaded in the infinite circulation path. The slider A linear guide device equipped with a ball holder that is mounted to prevent the balls from falling off, wherein the end cap has an arc-shaped outer peripheral groove corresponding to the curved path of the inner surface on the outer surface, The ball holder is made of a wire, and has a straight portion and locking portions formed at both ends of the linear portion and locked to the outer circumferential groove, and the locking portion is formed in a substantially arc shape and is a circle. A linear guide device characterized in that it is formed so that a relatively large clamping force is generated on the outer peripheral groove on the distal end side of the locking portion formed in an arc shape than on the base side. The front end side of the locking portion of the ball holder is in close contact with the groove bottom portion of the outer peripheral groove of the end cap, and the base side of the locking portion is not in contact with or lightly contacts the groove bottom portion of the outer peripheral groove of the end cap. The linear guide device according to claim 1 .   The front end side of the arc-shaped locking portion of the ball holder is formed such that its curvature is larger than the curvature of the outer peripheral groove of the end cap, and the curvature of the base side of the locking portion is that of the end cap. The linear guide device according to claim 1, wherein the linear guide device is formed so as to be smaller than a curvature of the outer circumferential groove. The arc-shaped locking portion of the ball holder is formed by a single arc, and the center of the arc is formed so as to be shifted to the guide rail side from the center of the arc of the outer peripheral groove of the end cap. The linear guide device according to claim 1, wherein:

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