JPH05196037A - Ball chain - Google Patents

Abstract

PURPOSE:To obtain a simple structure of ball chain which can be bent in a smaller bending by providing ball pieces between plural balls arranged in one line, and connecting the ball pieces with a movable connecting band provided with ball holes. CONSTITUTION:This ball chain 1 is composed of plural balls 8 arranged in one line making specific intervals, ball pieces 2 provided between the balls 8, and a movable connecting band 3 to connect the ball pieces 2. The ball pieces 2 are flat cylindrical members with the diameter smaller than the balls, and holding recesses 2a to hold the balls slidably are provided on both end faces of each ball piece. The connecting band 3 is a thin plate-form member extending along the central axis 0 of the balls, provided with a specific amount of the slipped to the central axis 0, and ball holes 4 with the diameter smaller than the balls are formed in the spaces between the ball pieces 2, so as to surround the outer peripheries of the balls 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball chain used in a linear motion guide device utilizing rolling of a ball.

[0002]

2. Description of the Related Art As a conventional ball chain of this type, there is one shown in FIGS. 15 (a) and 15 (b), for example. That is, a large number of unit chain elements 101 holding individual balls 100 are rotatably connected to each other through connecting pins 102 in an endless manner.

The unit chain element 101 is a ball 100.
Link plate 1 provided with a holding hole 103 for slidably holding
No. 04, and both ends of the link plate 104 are connected via the connecting pin 102 to form an endless ball chain.

This ball chain is used in a linear motion guide device 105 as shown in FIG. 16, and the balls 100, ... Are provided between the ball guide grooves 108, 109 facing each other between the track rail 106 and the slide base 107. It is designed to be rollable. The track rail 106 and the ball guide grooves 108 and 109 of the slide base 107 are V-shaped in cross section and have a Gothic arch structure for contacting the ball 100 at four points. The ball guide grooves 108 and 109 are provided at their bottoms with escape grooves 1 for avoiding interference with the link plate 104.
10 are provided.

[0005]

However, in the case of the above-mentioned prior art, since each chain unit element 101 is rotatably connected via the connecting pin 102, the structure is complicated and the chain assembly is extremely troublesome. there were.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a ball chain having a simple structure and easy to manufacture.

It is another object of the present invention to provide a ball chain suitable for preventing the ball from falling off to the outside especially when changing direction.

[0008]

In order to achieve the above object, in the present invention, a ball piece interposed between each ball of a plurality of balls arranged in a row at a predetermined interval, A flexible connecting band that connects between the ball pieces and has a ball hole into which the ball is inserted, and bends the connecting band between the ball pieces to chain a row of balls endlessly. It is possible to shift the connecting band by a predetermined amount so that it is located outside when the connecting band is bent with respect to the center line passing through the center of each ball, and the hole diameter of the ball hole is reduced to a diameter smaller than the ball diameter. Is characterized by.

Further, the connecting band is arranged along a center line passing through the center of each ball, and the holding allowance of the ball by the ball piece is an inner holding allowance when the connecting band is bent with respect to the ball center line. The outer holding margin may be set to be larger than that.

It is preferable that each ball piece is provided with a holding recess for slidably holding the ball, and the ball piece and the connecting band are integrally molded by injection molding. It is effective to insert and integrally mold with the ball.

[0011]

In the ball chain having the above structure, the connecting band between the ball pieces is bent to hold the balls in a row in an endless continuous manner, and the balls are mounted on the endless track of the linear motion guide device.

The assembly of this ball chain is
All that is required is to hold the balls between the ball pieces, the structure is simple, and the assembly is extremely easy.

Further, since the connecting band is provided so as to be displaced from the center axis of the ball by a predetermined amount and the hole diameter of the ball hole is narrowed to be smaller than the ball diameter, the ball is held by the hole edge of the ball hole. It is possible to prevent the ball from falling out.

The connecting band is set at the center of the ball,
By setting the holding margin of the ball piece larger on the outer side than on the inner side, it is possible to prevent the ball from falling out.

Particularly, if the ball is integrally formed with the ball piece and the connecting band by insert molding,
No assembly process is required.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. 1 to 3 (a) showing a ball chain according to a first embodiment of the present invention, reference numeral 1 denotes the entire ball chain, and the ball chain 1 is composed of a plurality of ball chains arranged at a predetermined interval. The ball 8 includes a ball piece 2 interposed between the balls 8 and a flexible connecting band 3 for connecting the ball pieces 2.

The ball piece 2 is a flat cylindrical member having a diameter smaller than the diameter of the ball, and holding recesses 2a for holding the ball 8 slidably are provided on both end faces thereof. The holding recess 2a is formed into a spherical shape into which the ball crown portion of the ball 8 is inserted.

On the other hand, the connecting band 3 is a thin plate member extending along the central axis O of the ball 8 and connects the ball pieces 2 together. The connecting band 3 is made of a flexible member, but in this embodiment, it is deformable only in the direction orthogonal to the plate surface. Also, the connecting band 3
A ball hole 4 is formed in the space between the ball pieces 2 so as to surround the outer circumference of the ball 8.

The connecting band 3 is provided so as to be displaced from the center line O connecting the centers of the balls 8 by a predetermined amount.

However, this ball chain 1 is shown in FIG.
As shown in FIG. 2, the connecting band 3 between the ball pieces 2 can be bent to form an endless ball chain. At that time, the connecting band 3 is arranged outside the center line O of the ball, the diameter of the ball hole 4 is narrowed to be smaller than the diameter of the ball 8, and the ball 8 is held by the edge of the ball hole 4. To prevent it from falling out.

The ball piece 2 and the connecting band 3 are integrally molded by injection molding, and in the present invention,
As shown in FIG. 4, the ball 8 is inserted into a molding die, and the ball 8 is integrally molded together.

The molding die for injection molding is divided into an upper die 6 and a lower die 7 with a surface orthogonal to the connecting band 3 as shown in FIG. 4, for example. The upper mold 6 and the lower mold 7 are provided with a third recess 11 for inserting the ball 8 in addition to the first and second recesses 9, 10 for molding the ball piece 2 and the connecting band 3. .

Then, as shown in FIG. 4 (a), the balls 8 are set in the third recesses 11 of the lower mold 7 opened as shown in FIG. 4 (b).
The mold is closed and the resin material is injected into the cavity as shown in FIG. Then, after the resin material is cured, the mold is opened and the molded product is released.

In this way, the step of assembling the ball 8 later is not required, and the productivity can be dramatically improved. At the time of this mold release, the ball 8'for forming the holding recess 2a of the ball piece 2 at the end portion is automatically released.

Further, the balls 8 held between the ball pieces 2 have a small gap between the balls 8 and the holding recess 2a due to the shrinkage of the material when the resin is cured, so that the sliding resistance can be reduced.

However, the structure of the molding die is not limited to the example shown in the drawing, and the molding surface may be a surface along the connecting band 3 as shown in FIG. 4 (e). Of course, it can be used.

5 to 7 show an example of a linear motion guide device using the ball chain 1.

This linear motion guide device includes a rail 20 and
The track stand 20 is composed of a slide stand 21 slidably mounted on the track stand 20 via a large number of balls 8.

Each ball 8 is incorporated in an infinite circulation path 22 formed in the slide base 21, and this infinite circulation path 22 is formed.
As shown in FIG. 8, a linear load ball passage 23 and an unloaded ball passage 24 extending in parallel with each other, and an arc-shaped direction change passage 25 connecting both ends of the load ball passage 23 and the unloaded ball passage 24. , 26, and the ball chain 1 holding the ball 8 is incorporated in the infinite circulation path 22.

The linear motion guide device of the illustrated example has a rail 20.
Is a four-direction equal load type in which four rows of balls are arranged symmetrically in the vertical and horizontal directions, two rows each on the left and right, and four infinite circulation paths 22, ... Are provided. One ball chain 1, ... Is incorporated into each infinite circulation path 22 ,.

That is, jetty walls 27, 27 extending in the longitudinal direction are provided on the left and right side surfaces of the track 20, and ball rolling grooves 28 are provided at both upper and lower corners of the jetty 27, 27.
On the other hand, a ball rolling groove 29 corresponding to the ball rolling groove 28 is provided on the inner surface of the slide base 21.
The ball 8 held by the ball chain 1 is interposed between 8 and 29 so as to be rollable to support the load. The ball rolling grooves 28 and 29 are circular arc grooves in this embodiment, and the ball 8 rolls by contacting at two points. Of course, it is not limited to the circular arc groove, for example, as shown in FIG.
It can also be used in the case of a Gothic arch groove as shown in FIG.

This ball 8 and each ball rolling groove 28, 29
The contact angle with the ball, that is, the horizontal direction of the rolling groove is drawn in the direction normal to the horizontal line H passing through the center of the left and right jetty 27, 27 and the contact portion of the ball 8 with the ball rolling groove 28, 29. The angle formed by the broken line, that is, the contact angle line X is approximately 45.
It is taken near the degree. Further, the illustrated example has a contact structure in which the left and right contact angle lines X, X, ...

The circulation plane C of each infinite circulation path 22, ...
Is the horizontal line H with respect to the contact angle line X direction of the ball 8.
The non-loaded ball passages 24, 24 are inclined at a predetermined angle toward the side closer to the vertical direction, and the vertical interval between the unloaded ball passages 24, 24 is narrowed to realize a stable linear motion guide device having a lower center of gravity.

The ball direction changing paths 25 and 26 are provided with side lids 21b and 2 attached to both end surfaces of the slide base body 21a.
It is formed by 1b.

Next, the movement of the ball 8 when the slide base 21 moves will be described.

When the slide base 21 moves with respect to the track base 20, the slide base 21 of the load ball passage 23 of the infinite circulation path 22 is moved.
The balls 8, ... Roll while supporting a load between the ball rolling grooves 28 and 29 of the track 20 and move in the moving direction of the slide 21.

By the movement of the ball 8 in this load range, each ball piece 2 moves in the movement direction of the slide base 21 together with the ball 8, and the ball chain 1 circulates infinitely in the infinite circulation path 22. Due to the movement of the ball chain 1, the unloaded ball passage 2 is sequentially introduced into the loaded ball passage 23 from the rear end in the moving direction of the slide base 21 through the ball direction changing passage 25.
A ball 8 is supplied from 4.

The balls 8 are held by the ball piece 2 during the entire course of the loaded ball passage 23, the direction changing passages 25 and 26, and the unloaded ball passage 24 of the endless circulation passage 22, so that the balls 8 are separated from each other. Align and move without interfering with each other.

The hole diameters of the direction changing passages 25 and 26 and the unloaded ball passage 24 are the same as those of the connecting bands 3 of the ball pieces 2.
The diameter of the ball 8 is larger than that of the ball 8 so that the ball 3 can move smoothly, and the ball 8 moves in the direction change paths 25 and 26 and the unloaded ball path 24.

Further, in this ball chain 1, since the connecting band 3 is bent at the position of the ball 8 held between the ball pieces 2, each ball 100 is held like the conventional ball chain shown in FIG. Link 104
A space corresponding to the connecting pin 102 between them is not required, and the span P between the balls 8 can be made as small as possible.
A large number of balls 8, ... Can be interposed in the load ball passage 23. Therefore, it is possible to reduce the load shared by each ball 8, ...

Since the span P between the balls 8, ... Is made small, the radius of curvature of the refraction circulation path of the ball chain 1 can be made as small as possible, and the radius of curvature R of the ball direction changing paths 25, 26 can be made as small as possible. Can be made smaller. As a result, the distance L between the loaded ball passage 23 and the unloaded ball passage 24 can be shortened, so that the size of the sliding base 21 can be further reduced.

Further, it is possible to effectively prevent the balls from falling out in the ball direction changing paths 25 and 26.

As described above, it was possible to realize a linear motion guide device having a large load bearing capacity, a compact size, and a low center of gravity.

The linear motion guide device to which the ball chain is applied is not limited to the infinite circulation type in which the ball chain is endless as shown in the drawing, but is also a finite sliding type in which the ball chain is used as it is. Can also be used.

Next, a second embodiment of the ball chain of the present invention will be described.

9 to 14 show a ball chain according to a second embodiment of the present invention. The same components as those in the above-mentioned first embodiment are designated by the same reference numerals and packed. It shall be.

In this embodiment, the connecting band 3'of the ball chain 1'is provided along the ball center line O, and the engagement margin of the ball 8 of the ball piece 2'is set to the ball center line O.
On the other hand, by setting the outer engagement margin B to be larger than the inner engagement margin A, the ball piece 2'prevents the ball 8 from falling out.

That is, although the ball piece 2'is cylindrical, the inner span is small when viewed from the side along the band surface of the connecting band 3'in order to increase the outer engagement margin B. It has a trapezoidal shape.

FIG. 12 shows an example of a molding die for injection molding the ball chain 1'with the balls 8 inserted. This molding die has a structure in which the upper die 6'and the lower die 7'are divided by the band surface of the connecting band ', but as shown in the first embodiment, the surface orthogonal to the connecting band 3'. The mold may be divided by this, and various other configurations can be applied.

13 and 14 show a state in which the linear guide device shown in FIG. 7 is incorporated.

Regarding other configurations and operations,
The description is omitted because it is the same as the embodiment.

[0052]

As described above, the present invention has the above-described structure and operation. The ball chain can be assembled simply by holding the balls between the ball pieces, and the structure is simple and the assembly is extremely easy.

Further, since the connecting band is displaced by a predetermined amount so as to be positioned outside when it is bent endlessly with respect to the center axis of the ball, and the hole diameter of the ball hole of the connecting band is reduced to a diameter smaller than the ball diameter. It is possible to prevent the ball from falling off when circulating on an endless track, especially when changing direction.

On the other hand, the connecting band is set at the center of the ball,
It is also possible to prevent the ball from falling out by setting the holding allowance of the ball piece larger on the outer side than on the inner side.

Furthermore, if the ball is integrally molded with the ball piece and the connecting band by insert molding,
As a result, the assembly process is completely unnecessary and the production is extremely easy.

[Brief description of drawings]

FIG. 1 shows a ball chain according to a first embodiment of the present invention. FIG. 1 (a) is a plan view, FIG. 1 (b) is a front view, and FIG. 1 (c) is a rear view. The same figure (d) is a left side view, the same figure (e)
Is a right side view.

FIG. 2 is a partial front view of the ball chain of FIG. 1 in a bent state.

3 is a perspective view of the ball chain of FIG. 1. FIG.

4 shows an injection molding process of the ball chain of FIG. 1, and FIG. 4 (a) is a side sectional view of a main part in a mold open state,
The same figure (b) is a sectional view taken along the line BB of the same figure (a), the same figure (c) is a sectional view of the main part at the time of injection, and the same figure (d) is a sectional view of the main part at the time of mold release.
(e) is a sectional view showing another embodiment of the molding die.

5 is a longitudinal sectional view showing an example of a linear motion guide device incorporating the ball chain of FIG.

FIG. 6 is a cross-sectional view of one infinite circuit of FIG.

FIG. 7 is a perspective view of the device of FIG.

FIG. 8 is a cross-sectional view of essential parts showing a Gothic arch type ball rolling groove.

FIG. 9 shows a ball chain according to a second embodiment of the present invention. FIG. 9 (a) is a plan view, FIG. 9 (b) is a front view, and FIG. 9 (c) is a rear view. The same figure (d) is a left side view, the same figure (e)
Is a right side view.

FIG. 10 is a partial front view of the ball chain of FIG. 9 in a bent state.

FIG. 11 is a perspective view of the ball chain shown in FIG. 9.

12 is a sectional view of an example of a molding die for injection molding of the ball chain shown in FIG. 9;

FIG. 13 is a vertical cross-sectional view showing an example of a linear motion guide device incorporating the ball chain of FIG.

14 is a cross-sectional view of one infinite circuit of FIG.

FIG. 15 shows a conventional ball chain.
(a) is a partial front view and (b) is a plan sectional view.

16 is a vertical cross-sectional view of a linear motion guide device using the ball chain of FIG.

[Explanation of symbols]

 1 ball chain 2 ball piece 3 connecting band 4 ball hole 6 upper mold 7 lower mold 8 ball 20 raceway 21 sliding table 22 infinite circulation path 23 loaded ball path 24 unloaded ball path 25, 26 ball direction change path O ball row Central axis of

Claims (4)

[Claims] 1. A ball piece interposed between balls of a plurality of balls arranged in a line at a predetermined interval,
A flexible connecting band that connects between the ball pieces and has a ball hole into which the ball is inserted, and bends the connecting band between the ball pieces to chain a row of balls endlessly. It is possible to shift the connecting band by a predetermined amount so as to be located outside when the connecting band is bent with respect to a center line passing through the center of each ball, and the hole diameter of the ball hole is reduced to a diameter smaller than the ball diameter. Ball chain characterized by. 2. A ball piece interposed between balls of a plurality of balls arranged in a line at a predetermined interval,
A flexible connecting band that connects between the ball pieces and has a ball hole into which the ball is inserted, and bends the connecting band between the ball pieces to chain a row of balls endlessly. It is possible to arrange the connecting band along a center line passing through the center of each ball, and the holding allowance of the ball by the ball piece is larger than the inner holding allowance when the connecting band is bent with respect to the ball center line. A ball chain with a large outer holding allowance. 3. The ball chain according to claim 1, wherein each ball piece is provided with a holding recess for slidably holding the ball. 4. The ball chain according to claim 3, wherein the ball piece and the connecting band are integrally molded by injection molding, and the ball is inserted into a molding die and integrally molded with the ball.