JPH07208467A - Linear guiding device - Google Patents

Abstract

PURPOSE:To provide a smooth circulation of balls and prevent generation of noise at the time of circulation of balls by making the locus of balls circulated in a sliding base a continous line while supplying a sufficient amount of lublicant to a ball returning path and ball returning hole. CONSTITUTION:A ball retaining path 32 in which balls 3 roll is composed of an outer ball guide face 32a positioned at the outside of circular arc drawn by balls 3 and an inner ball guide face 32b positioned at the inner side. A ball 3 is at its two points in contact with the face 32a while it is at its one point in contact with the face 32b. The ball 3 comes, at its three points, in contact with the inner dia. of the path 32, and it 3 rolls in the bath 32 drawing a specified arc locus as shown by the dotted line. A gap is formed between between the center of the face 32a and ball 3 and thus lublicant such as grease can be retained and lublication between the ball 3 and the return path 32 is not damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear guide device used in a slide portion of various industrial machines, and more specifically, while circulating a ball sandwiched between a slide base and a track rail, The present invention relates to an improvement of a linear guide device in which a slide base makes an infinite stroke linear motion along a track rail.

[0002]

2. Description of the Related Art Heretofore, as a linear guide device of this type, one disclosed in Japanese Patent Publication No. 3-51930 is known. Specifically, as shown in FIG. 17, a track rail 100 arranged on a fixed portion (not shown) such as a bed, a slide base 101 moving along the track rail 100, and a slide table 101. A pair of lids 1 fixed to both front and rear surfaces of the base 101
02 and a large number of balls 105 which are sandwiched between the ball rolling groove 103 of the track rail 100 and the load ball groove 104 of the slide base 101 and roll while applying a load. A ball return hole 106 parallel to the load ball groove 104 is formed in the slide base 101,
An arc-shaped ball reversal path 107 that connects the load ball groove 104 and the ball return hole 106 is formed in the lid 102, and the ball 105 is loaded into the load ball groove 104 via the ball reversal path 107 and the ball return hole 106. It circulates between the ends of the.

18 and 19 show details of the ball reversal path 107 formed in the lid body 102. As shown in FIG. The ball reversal path 107 has an inner diameter slightly larger than the diameter of the ball 105, and has an outer ball guide surface 107a having a semicircular cross section formed on the lid body 102a, and the lid body 10.
The inner ball guide surface 107b, which has a semicircular cross section and is formed on the return piece 102b that fits into the 2a, is formed to face each other. That is, the ball reversal path 107 has a circular cross section and its inner diameter is formed larger than the diameter of the ball 105, so that the ball 105 rolls in the ball reversal path 107 in an unloaded state. Further, a tongue piece 108 is formed to project at the end of the outer ball guide surface 107a on the side of the loaded ball groove 104, and the ball 105 rolling in the ball rolling groove 103 of the track rail 100 is guided to the ball reversal path 107. It is supposed to scoop up.

On the other hand, Japanese Laid-Open Patent Publication No. 62-46015 discloses a linear guide device in which the ball reversal path and the ball return hole are formed by a tube body. Also in this device, the cross section of the tube body is formed in a circular shape having an inner diameter slightly larger than the diameter of the ball, and the end of the tube body on the side of the loaded ball groove is also rolled in the ball rolling groove of the track rail. A tongue that scoops the moving ball on the tube is formed to project.

[0005]

By the way, when the smoothness of ball circulation in such a linear guide device is examined, the trajectory of the ball in each of the loaded ball groove, the ball inversion path and the ball return hole does not meander. Further, it is desirable that the trajectory of the ball is smoothly continuous at the connecting portion between the ball reversing path and the loaded ball groove and at the connecting portion between the ball reversing path and the ball return hole. That is, it is considered that the ball circulates smoothly without resistance if the trajectory of the ball circulation is a smooth continuous line as shown by the one-dot chain line in FIG.

However, as described above, in the conventional linear guide device, the cross section of the ball reversing path is formed in a circular shape having an inner diameter larger than the ball diameter, and therefore, as shown by the broken line in FIG. On the road, the ball draws an unstable meandering trajectory without drawing a constant arcuate trajectory. Also, the ball rolling in the loaded ball groove collides with the tongue protruding from the end of the ball reversal path and is scooped up in the ball reversal path. A step as shown in FIG. 21 is generated in the circulation locus.

For this reason, in the conventional linear guide device, the ball is clogged in the ball reversing path, or resistance acts on the ball passing through the connecting portion between the ball reversing path and the load ball groove, which prevents smooth circulation of the ball. There was a problem.
Further, when the ball passes through the connecting portion between the ball reversing path and the loaded ball groove, the ball collides with the tongue piece or the track rail, which causes noise.

It is easily conceivable that the inner diameter of the ball reversing passage or the ball returning hole should be close to the ball diameter in order to solve such a problem. Since a lubricant such as grease is supplied from the outside to the ball, if the inner diameter of the ball reversing passage is brought close to the ball diameter, the lubricant will be extruded by the ball from the ball reversing passage and the ball return hole. However, a new problem arises in that a sufficient amount of lubricant cannot be supplied to the ball inversion path and the ball return hole.

The present invention has been made in view of the above problems, and an object of the present invention is to supply a sufficient amount of lubricant to the ball reversing passage and the ball return hole while at the same time, inside the sliding base. It is an object of the present invention to provide a linear guide device capable of achieving smooth circulation of a ball and suppressing generation of noise accompanying the circulation of the ball by making the trajectory of the ball circulating in a smooth continuous line.

[0010]

[Means for Solving the Problems] First, in order to achieve the above-mentioned object, the present inventors have proposed a linear guide device according to claim 1.
That is, a track rail having a ball rolling groove formed along the longitudinal direction, a load ball groove facing the ball rolling groove, and a ball return hole parallel to the load ball groove are formed. And sandwiched between a slide base having a ball reversing path connecting the load ball groove and the ball return hole, a ball rolling groove of the raceway and a load ball groove of the slide base, and Of the ball guide surface formed on the inner diameter of the pipe body, the ball reversal path is composed of a large number of balls that circulate in the loaded ball groove and the ball return hole through the ball reversal path. , The ball is brought into contact with the ball guide surface located outside the arc at two points, while the ball is brought into contact with the ball guide surface located inside the arc at one point and fed into the ball reversing path. A ball It proposes a linear guide device for guiding along a predetermined trajectory.

According to the linear guide device of the first aspect, the arc-shaped ball reversing path is formed of a pipe body, and two balls are in contact with the outer ball guiding surface of the pipe while the inner ball guiding surface is in contact with the ball. Since the ball is in contact with the pipe body at one point, the ball rolls in the pipe body while contacting the inner diameter of the pipe body at three points. Therefore, the ball can be prevented from meandering in the ball reversal path by always rolling along the ball reversal path in a predetermined arcuate path.

Further, since the balls are in contact with the inner diameter of the pipe body at three points, a sufficient gap can be formed between the ball and the pipe body in the portion where the balls are not in contact with the pipe body. The lubricant can be retained in the gap.

In such technical means, from the viewpoint of ensuring smooth continuity of the trajectory of the ball in the connection portion between the ball reversal path and the ball return hole, the sliding movement as described in claim 2 It is preferable that a boss hole is formed around the ball return hole opened on both end faces of the base, and one end of the pipe body is fitted into the boss hole and positioned.
According to this structure, the center of the ball reversing path and the center of the ball returning hole are always aligned with each other, so that the ball can smoothly roll at the connecting portion between the ball reversing path and the ball returning hole.

Further, in order to reduce the resistance when the ball circulates, it is desirable that the rolling state of the ball in the ball return hole and that in the ball reversing path are kept substantially the same. The linear guide device according to a third aspect is an improvement of the linear guide device according to the first aspect based on this point of view. The ball return hole is formed by a pipe body continuous from the ball reversal path, and the inner diameter thereof is also formed. The shape is the same as the inner diameter of the ball reversal path. According to this structure, the ball that was in contact with the inner diameter of the pipe body at three points in the ball reversing path also rolls while being in contact with the inner diameter of the pipe body at three points in the ball return hole. Rolling of the ball from the inversion path to the ball return hole becomes smoother.

A fourth aspect proposes a concrete structure of the pipe body shown in the third aspect. That is, a pipe body in which a ball reversal path / ball return hole / ball reversal path is continuous is divided into four half-split pipes formed in a substantially J shape, while the sliding base has a straight portion of the half split pipes. A pair of halved pipes that penetrate through the pipe body mounting holes to which they are fitted and are opposed to each other are combined and fitted into both ends of the pipe body mounting holes. When the pipe body is composed of four half-split pipes in this manner, each half-split pipe can be manufactured by injection molding of synthetic resin or the like, and the ball guide surface having the inner diameter of the pipe body has the predetermined shape. Can be accurately molded into the shape of. Further, since a pair of half pipes facing each other are combined and fitted into both ends of the pipe body mounting hole, the pipe body can be assembled and positioned accurately.

Further, as for the pair of half-divided pipes which face each other and are fitted into the pipe body mounting holes, the lengths of the straight portions inserted into the pipe body mounting holes are different from each other. Preferably. With this configuration, the seams of the half pipes inserted into the pipe body mounting holes from different directions are located at different positions on the left and right sides in the ball rolling direction. Therefore, when the ball passes through the gap or the step existing at the joint of the half pipe, the half pipe located on the side opposite to the seam sandwiching the ball always guides the ball. The trajectory of the ball is not greatly disturbed. Therefore, the circulation resistance of the ball can be reduced.

On the other hand, from the viewpoint of ensuring a smooth continuity of the trajectory of the ball at the connecting portion between the ball reversing path and the loaded ball groove, as shown in claim 6, an arc-shaped ball reversing path is formed. At the inlet of the load ball groove side of the pipe body to form a ball scooping part which is cut out of the outer ball guide surface in parallel with the ball rolling groove of the track rail,
Further, it is preferable that the trajectory of contact of the ball with the outer ball guide surface is continuous to the load ball groove side entrance of the pipe body. According to this structure, no step is generated in the trajectory of the ball at the connection portion between the load ball groove and the ball reversing path, and the direction of the ball entering the load ball groove from the ball reversing path is 180 °. Until it is held on the outer ball guide surface, the trajectory of the ball in the ball reversing path becomes smoothly continuous with the trajectory of the ball in the load ball groove, and at the connecting portion of the ball reversing path and the load ball groove. Smooth rolling of the ball can be achieved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The linear guide device of the present invention will be described in detail below with reference to the accompanying drawings. 1 and 2 show a first embodiment of the present invention. In these drawings, reference numeral 1 is a track rail, and a total of four ball rolling grooves 11 are formed along the longitudinal direction on both side surfaces and an upper surface thereof, and mounting holes 12 for fixing bolts are provided at appropriate intervals. It is provided. Further, reference numeral 2 is a sliding base formed in a channel shape and straddling the track rail 1, and a mounting surface 21 of a movable body (not shown) is formed on the upper surface of the sliding base, and the movable body is mounted. A bolt hole 22 into which a bolt (not shown) is screwed is provided.

As shown in the sectional views of FIGS. 3 to 5, the slide base 2 includes a slide block 20 having a load ball groove 23 and a ball return hole 24, and a circle at both ends in the moving direction of the slide block. The pipe body 30 forms an arc-shaped ball reversal path, and the pipe cover 40 is attached to the slide block 20 so as to cover the pipe body 30.

The load ball groove 23 formed in the slide block 20 is formed so as to face each ball rolling groove 11 formed in the track rail 1, and the load ball groove 23 and the ball rolling groove 11 are formed. A large number of balls 3 are interposed between them. In this embodiment, each ball rolling groove 11
As for the contact angle of the ball 3 rolling on the track, the contact angle of the ball 3 rolling on both side surfaces of the track rail 1 is 3 with respect to the thrust direction.
The contact angle of the ball 3 rolling on the upper surface of the track rail 1 coincides with the radial direction.

The ball return holes 24 are bored in parallel with the loaded ball grooves 23 corresponding to the loaded ball grooves 23, and are opened at both end surfaces in the moving direction of the slide block 20. The openings at both ends of the ball return hole 24 are connected to both ends of the load ball groove 23 through a pair of pipe bodies 30 to form an endless circulation path for the balls 3 as shown in FIG.

The pipe body 30 is formed by combining a half-split pipe 31 shown in FIG. 6 and a half-split pipe 31 having a mirror image relationship with each other. The path 32 is formed in an arc shape.
Further, a positioning boss 33 is provided on the half pipe 31 so that the positioning boss 33 fits into a boss hole 25 formed around the opening of the ball return hole 24. Configured (see Figure 3).

Further, as shown in FIG. 7, the pipe cover 40 substantially matches the cross-sectional shape of the slide block 20 in the moving direction, and the pipe body 30 is fitted on the inner surface side in contact with the end surface of the slide block 20. A recess 41 that fits in is formed corresponding to each load ball groove 23 on the slide block 20 side. In the figure, reference numeral 44 is a through hole of the coupling bolt 43 screwed into the slide block 20.

The pipe cover 40 is made of a material such as hard rubber or engineering plastic, and is attached to the end surface of the slide block 20 to cover the four pipe bodies 30 at the same time.
This prevents the mounting error of the slide block 20 from being propagated to other pipe bodies 30 and adversely affecting the positioning thereof. Further, as shown in FIG. 1 to FIG. 3 or FIG. 10, a seal portion 42 that is in close contact with the track rail 1 is formed on the outer surface side of the pipe cover 40 so that dust can enter the inside of the slide base 2. To prevent it.

As shown in FIG. 8, the sliding base 2 having the above-described structure forms a pipe body 30 by combining a pair of halved pipes 31, 31 facing each other, and then positioning the pipe body 30. Boss 33 for slide block 2
The pipe body 30 is attached to the slide block 20 by fitting it into the boss hole 25 of No. 0, and finally the pipe cover 40 is fixed to the slide block 20 from above the pipe body 30 with the connecting bolt 43. As a result, the ends of the loaded ball groove 23 and the ball return hole 24 of the slide block 20 are connected by the ball reversing path 32, and an infinite circulation path for the balls 3 is formed on the slide base 2.

FIG. 9 shows the rolling state of the balls 3 inside the pipe body 30 constructed by combining the half pipes 31 and 31. The ball reversal path 32 along which the ball 3 rolls consists of an outer ball guide surface 32a located outside the arc drawn by the ball 3 and an inner ball guide surface 32b located inside, and as shown in FIG. The ball 3 is in two-point contact with the ball guide surface 32a, while the ball 3 is in one-point contact with the inner ball guide surface 32b. Therefore, the ball 3 is the ball reversal path 3 described above.
Three points of contact with the inner diameter of No. 2 are drawn, and the ball reversing path 32 rolls along a constant arcuate locus as shown by the alternate long and short dash line in FIG.
In this embodiment, the contact angle of the ball 3 with the outer ball guide surface 32a is set to 30 °.

Further, the ball 3 has an outer ball guide surface 32a.
Since they are in contact with each other at two points, a gap is formed between the center of the outer ball guide surface 32a and the ball 3, as shown in FIG. Therefore, a lubricant such as grease can be held in this gap, and the lubrication between the ball 3 and the ball reversal path 32 is not impaired.

Further, the outer ball guide surface 3 of the pipe body 30.
2a is notched in parallel with the ball rolling groove 11 of the track rail 1 at the entrance on the side of the loaded ball groove 23, and a semi-elliptical ball scooping portion 34 as shown in FIG. 11 is formed. As a result, the ball 3 rolling in the loaded ball groove 23 is gradually scooped from both sides of its spherical surface from below and then enters the ball reversing path 32. At this time, if the ball scooping portion 34 is formed such that the contact trajectory of the ball with respect to the outer ball guide surface 32a is continuous over the entire area of the ball reversing path 32 formed in an arc shape of 180 °, the ball 3 scoops the ball. Regardless of the presence or absence of the portion 34, an arcuate locus shown by a chain line in FIG. Continuous.

Therefore, the balls 3 rolling in the loaded ball groove 23 are scooped by the ball scooping portion 34 formed on the pipe body 30.
In addition, the ball 3 entering the loaded ball groove 23 from the ball reversing path 32 does not collide with the ball rolling groove 11 of the track rail 1.

In the first embodiment, the pipe body 30 is formed by combining the pair of half-split pipes 31, 31 having symmetrical shapes, but as shown in FIGS. 12 and 13, the outer ball guide surface is formed. Outer piece 3 with 32a formed
5 and the inner piece 36 having the inner ball guide surface 32b may be combined to form the pipe body 30. By thus dividing the pipe body 30 along the circumferential direction, the ball scooping portion 34 located at the end of the outer ball guide surface 32a can be accurately formed.

Next, a second embodiment of the present invention will be described. FIG. 14 is a sectional view showing the features of the linear guide device according to the second embodiment, and corresponds to the sectional view of the first embodiment shown in FIG. In the figure, reference numeral 5 is a track rail, reference numeral 6
Is a slide base, and this slide base 6 includes a slide block 60 in which a load ball groove 61 is formed and a ball reversing path 72.
And a pipe body 70 in which a ball return hole 73 is integrally formed
And a pipe cover 80 for fixing the pipe body 70 to the slide block 60. Since the track rail 5 and the pipe cover 80 are the same as the track rail 1 and the pipe cover 40 described in the first embodiment, the description thereof will be omitted here. The appearance of the linear guide device according to the second embodiment is the same as that of the first embodiment shown in FIGS. 1 and 2.

The pipe body 70 is provided with arcuate ball reversing paths 72 at both ends of a straight ball return hole 73, and is assembled from four half-split pipes formed in a substantially J shape. . As shown in FIG. 15, the half pipe has two kinds of big and small half pipes 71a and 71b whose straight portions have different lengths, and the pipe body 70 uses these half pipes 71a and 71b in the slide block 60. It is assembled by inserting it from both ends of the pipe body mounting hole 62 formed through.

In assembling the slide table 6, as shown in FIG. 16, the half pipes 7 having straight portions having different lengths are used.
1a and 71b are combined and fitted to both ends of the pipe body mounting hole 62 of the slide block 60, and a pipe cover 80 covering the pipe body 70 is attached to the end surface of the slide block 60 by a coupling bolt 81.

By thus forming the pipe body 70 by combining the half-split pipes 71a and 71b whose straight portions have mutually different lengths, the seam of the half-split pipes 71a and 71b in the longitudinal direction of the ball return hole is ball-rolled. It occurs at different positions with respect to the left and right of the moving direction. Therefore, when the ball 3 passes through a gap or a step existing at the seam of the half pipes 71a and 71b, the half pipe 71a located on the opposite side of the seam with the ball 3 in between must surely come into contact with the ball 3. Is guiding you. Therefore, the half pipe 71
The trajectory of the ball 3 is not significantly disturbed even when passing through the joint of a and 71b, and the circulation resistance of the ball 3 can be reduced.

Further, in this embodiment, the pipe body 70
The inner diameter shapes of the ball reversal passage 72 and the ball return hole 73 formed in the above are the same as the inner diameter shape of the ball reversal passage 32 shown in the first embodiment, that is, the same as that shown in FIG. Further, the shape of the ball scooping portion 74 formed at the entrance of the ball reversing path 72 on the side of the loaded ball groove 61 is also the same as the shape of the ball scooping portion 34 shown in the first embodiment, that is, the one shown in FIG. .

Therefore, in this embodiment, the rolling state of the ball 3 is the same in the ball reversing path 62 and the ball returning hole 63, and the trajectory of the ball 3 in these paths is smooth and continuous. As described in the embodiment, the trajectory of the ball 3 rolling in the loaded ball groove 61 and the trajectory of the ball 3 rolling in the ball reversing path 32 are smoothly continuous. That is, in this embodiment, the trajectory of the ball 3 circulating inside the slide table 6 is similar to the ideal ball circulation trajectory shown in FIG.

As a result, in the present embodiment, it is possible to achieve smooth circulation of the balls and to reduce noise during traveling of the slide base.

[0038]

As described above, according to the linear guide device of the present invention, the balls circulated inside the slide base while supplying a sufficient amount of lubricant to the ball reversing path and the ball return hole. Can be made into a smooth continuous line, whereby smooth circulation of the ball can be achieved and generation of noise due to ball circulation can be suppressed.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a linear guide device of the present invention.

FIG. 2 is a front view of the linear guide device according to the first embodiment.

FIG. 3 is a side view of the linear guide device according to the first embodiment, and a slide base is a III-III battle sectional view of FIG.

4 is a sectional view taken along line IV-IV of FIG.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a front view showing a half pipe according to the first embodiment,
It is a side view and a sectional view.

FIG. 7 is a perspective view showing a pipe cover according to the first embodiment.

FIG. 8 is an exploded perspective view of a slide base according to the first embodiment.

FIG. 9 is a cross-sectional view of essential parts showing a ball circulating state in the sliding table according to the first embodiment.

10 is a cross-sectional view taken along line XX of FIG.

FIG. 11 is a view showing a ball scooping portion of the pipe body according to the first embodiment.

FIG. 12 is an exploded perspective view showing a modified example of the pipe body according to the first embodiment.

FIG. 13 is a perspective view showing a modified example of the pipe body according to the first embodiment.

14 is a side view showing a second embodiment of the linear guide device of the present invention, and the slide table is a sectional view corresponding to the line III-III in FIG. 2. FIG.

FIG. 15 is a side view showing a half pipe according to a second embodiment.

FIG. 16 is an exploded perspective view of a slide base according to a second embodiment.

FIG. 17 is a perspective view showing a conventional linear guide device (partially cutaway view).

FIG. 18 is a sectional view showing a lid of a conventional linear guide device.

FIG. 19 is a sectional view taken along line XIX-XIX in FIG. 18.

FIG. 20 is a diagram showing an ideal ball circulation trajectory.

FIG. 21 is a diagram showing a conventional ball circulation trajectory.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Track rail, 2 ... Sliding base, 3 ... Ball, 11 ... Ball rolling groove, 23 ... Loaded ball groove, 24 ... Ball return hole,
25 ... Boss hole, 30 ... Pipe body, 31 ... Half pipe, 3
2 ... Ball reversing path, 32a ... Outer ball guide surface, 32b
Inner ball guide surface, 33 ... Positioning boss, 34 ... Ball scooping part

Claims (6)

[Claims] 1. A track rail having a ball rolling groove formed in the longitudinal direction, a load ball groove facing the ball rolling groove, and a ball return hole parallel to the load ball groove. And a slide base having an arc-shaped ball reversal path connecting the load ball groove and the ball return hole, and a load is applied while rolling between the ball rolling groove and the load ball groove. In a linear guide device composed of a large number of balls that are loaded and circulate through a loaded ball groove and a ball return hole through the ball reversing path, the ball reversing path is formed of a pipe body, and Among the ball guide surfaces formed on the inner diameter, the ball guide surface located outside the arc is brought into contact with the ball at two points, while the ball guide surface located inside the arc is located at one point. Contact Linear guide apparatus characterized by guiding to along the ball sent into the serial ball reversing path at a constant locus. 2. The linear guide device according to claim 1,
A ball return hole is formed in the slide base, and boss holes are formed around openings at both ends of the slide base, and a positioning boss formed at one end of the pipe body is fitted into the boss hole. A straight line guide device. 3. The linear guide device according to claim 1, wherein
A linear guide device characterized in that the ball return hole is constituted by a pipe body continuing from the ball reversing path, and the inner diameter shape thereof is the same as the inner diameter shape of the ball reversing path. 4. The linear guide device according to claim 3,
The pipe body in which the ball inversion path / ball return hole / ball inversion path is continuous is divided into four half-split pipes formed in a substantially J shape, while the straight portion of the half split pipe is fitted to the slide table. A linear guide device, characterized in that a pair of half-divided pipes, which penetrate through the corresponding pipe body mounting holes and are opposed to each other, are combined and fitted into both ends of the pipe body mounting holes. 5. The linear guide device according to claim 4,
A straight guide device in which a pair of half-divided pipes facing each other and fitted into the pipe body mounting holes have different lengths of straight line portions fitted into the pipe body mounting holes. 6. The straight guide device according to claim 1, wherein the outer ball guide surface is provided at the inlet of the pipe body forming the ball reversing path on the side of the load ball groove and the ball rolling groove of the track rail. A linear guide device, wherein a ball scooping portion which is cut out in parallel is formed, and a contact trajectory of the ball with respect to the outer ball guide surface is continuous to an inlet on the loaded ball groove side of the pipe body.