JP3488025B2 - Ball chain - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in such a manner that a large number of balls are arranged in a row and held so as to be rollable, and are incorporated in, for example, a linear guide device for endless sliding or a ball endless track of a ball screw device. The present invention relates to a ball chain, and more particularly to a ball chain that can be flexibly bent or twisted before use.

[0002]

2. Description of the Related Art Conventionally, as a linear guide device for guiding a movable body such as a table along a fixed portion such as a bed, a track rail having a ball rolling groove and a load rolling surface facing the ball rolling groove. A slider that has a running groove and an unloaded rolling path that circulates balls from one end of the loaded rolling groove to the other end, and a slider that moves along the track rail, and a load between the slider and the track rail. It is known that the ball comprises a number of balls that roll while loading and that circulate in an endless track formed by the loaded rolling groove and the unloaded rolling path of the slider.

In the conventional linear guide device constructed as above, since the endless track of the slider is filled with balls, when the slider moves along the track rail,
The balls adjacent to each other circulate in the above-mentioned endless track while colliding or rubbing against each other, and there is a problem that the balls wear early and the life of the device is shortened.

Therefore, as a solution to such a problem, there has been proposed a linear guide device in which a ball chain in which a large number of balls are aligned and held is incorporated in the endless track (Japanese Patent Laid-Open No. 5-52217). As shown in FIGS. 8 and 9, the ball chain 100 has a spacer 102 interposed between adjacent balls 101, and
Each spacer 102 is connected by a pair of belt members 103 along the ball arrangement direction to connect the balls 101 in a beaded shape. The balls 101 are made of a flexible resin arranged as a core in a mold. It is manufactured by injection molding.

The conventional ball chain 100 having such a structure is incorporated in the endless track 105 of the slider 104 and circulates in the endless track as shown in FIG. Since the spacer 102 is interposed between them, mutual friction and collision of the balls can be prevented, and wear of the balls 101 can be prevented as much as possible.

[0006]

However, in such a conventional ball chain 100, since the side edge of the belt member 103 connecting the spacers 102 is linearly formed, it intersects with the surface of the belt member 103. Although it is easy to bend the ball chain 100 in the direction (arrow A in FIG. 9), it is difficult to bend the ball chain 100 in a direction parallel to the surface of the belt member 103 (direction B in FIG. 8). Yes, depending on the design of the ball track, the above ball chain 10
It was difficult to incorporate 0.

That is, as shown in FIG. 11, since the ball chain 100 sandwiched between the ball rolling groove 107 of the track rail 106 and the load rolling groove 109 of the slider 108 is restrained in its posture, Above ball rolling groove 1
In the case where the ball endless track 105 exists in the plane where the 07 and the load rolling groove 109 face each other (in the plane shown by the alternate long and short dash line in FIG. 11), the ball chain 100 can be flexed without difficulty. The ball endless track 10 is in a plane greatly inclined from the plane (for example, in a plane indicated by a chain double-dashed line).
5 exists, the belt member 103 hinders the free bending of the ball chain 100, which hinders the smooth circulation of the ball chain 100 in the endless track.

On the other hand, in a ball screw device which is used for converting the rotational motion of a motor into a linear motion and which is used in combination with the above-mentioned linear guide device to form a linear guide portion of a machine tool or the like, a screw shaft and a nut member are used. And are screwed together via a ball, and the nut member is also provided with an endless track of the ball. Therefore, from the viewpoint of preventing wear of the balls circulating inside the nut member, it can be said that it is preferable to incorporate the ball chain in the endless track of this ball screw device as well, but as described above, the conventional balls are not used. Since the chain has a structure that is easily bent only in a specific direction, it has been difficult to incorporate this into the ball endless track of the ball screw device.

That is, when the ball chain is installed in the ball endless track of the ball screw device, it is necessary to wind the ball chain spirally around the screw shaft, and the ball chain is circulated three-dimensionally instead of planarly. Since it is necessary, it was not possible to expect smooth circulation of the ball chain in the endless track with the conventional ball chain having a small degree of freedom in the bending direction. Also,
When a ball chain is incorporated into a ball screw device, the ball chain must circulate in an endless track with some twist, but the conventional ball chain with low flexibility cannot be twisted by force. There is a concern that the ball may fall off from the ball chain itself when used as

The present invention has been made in view of the above problems, and it is an object of the present invention to flexibly bend in any direction, and when bending or twisting is given. Even in this case, it is to provide a ball chain which can circulate inside a ball endless track while holding the ball securely.

[0011]

That is, a ball chain according to the present invention has a large number of balls arranged in a row at a predetermined interval and rotatably holding the balls and adjoining the balls adjacent to each other. A ball chain composed of a connected connecting belt, wherein the connecting belt has four belt members formed in a band shape along the spherical surface of the ball and along the arrangement direction of the balls. On the other hand, the belt member is mutually connected to another belt member between adjacent balls, and at the connecting position, the connecting belt is formed in a shape narrower than the outer diameter of the ball. To do.

According to such technical means, the connecting belt has four belt members formed in a band shape along the spherical surface of the ball and along the arrangement direction of the balls. Since the balls are interconnected with other belt members between the balls adjacent to each other, the individual balls are surrounded by the belt members from all sides, and even if the ball chain is given a large bend or twist. Even in the case of hitting, the ball does not fall out of the connecting belt. Therefore, even if the slider of the linear guide device is pulled out from the track rail, or even if the nut member of the ball screw device is pulled out from the screw shaft, the balls of these sliders or nut members can be removed without using the ball cage. It is possible to prevent the ball from rolling off the endless track.

Further, since the above-mentioned connecting belt is formed in a position where four belt members are connected to each other, that is, between adjacent balls, the connecting belt is formed in a shape narrower than the outer diameter of the balls. The chain is flexibly bent in any direction at the position, and has a structure that easily absorbs a twist acting on the ball chain. Therefore, the ball chain can be used by bending or twisting it freely in any direction regardless of the position where the belt member is formed with respect to the row of balls. It is something that can be circulated to.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The ball chain of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of a ball chain 1 of the present invention. The ball chain 1 is formed by arranging a plurality of balls 3 in a row on a joint belt 2 made of synthetic resin at predetermined intervals, and the balls 3 are freely rotatable while being held by the joint belt 2. Has become.

The connecting belt 2 has four belt members 5 formed in strips along the spherical surface of the balls 3 and along the arrangement direction of the balls 3, and the belt member 4
Are mutually connected to another belt member 5 between the balls 3 and 3 adjacent to each other. Further, a disc-shaped connecting portion 4 is formed between the balls 3 adjacent to each other,
Each belt member 5 is interconnected with another belt member 5 via the connecting portion 4, and the connecting portion 4 also serves as a spacer for preventing contact between the balls 3 adjacent to each other.

As shown in FIG. 2, the belt member 5 is arranged on the upper and lower sides of the ball row so as to divide the spherical surface of the ball 3 into four equal parts, and the ball 3 has a pair of connecting portions 4 adjacent thereto. The movement of the ball 3 is restrained from four directions so that the ball 3 cannot be slipped out. Further, the belt member 5 is formed along the spherical surface of the ball 3, and when the ball chain 1 is observed as a whole, the connecting belt 2 has the most constricted shape at the position where the connecting portion 4 is formed. ing.

The ball chain 1 is molded by injection molding of a synthetic resin in which the balls 3 are arranged in a mold, and after the molding is completed, the connecting belt 2 is released from the mold together with the balls 3. To be done. In addition, if the connecting belt 2 is simply injection-molded, the connecting portion 4 and the belt member 5 of the belt 2 come into close contact with the balls 3, and the balls 3 do not freely rotate with respect to the connecting belt 2. In this embodiment, the ball chain 1 after completion of molding is dipped in a mineral oil-based lubricating oil, and a swelling of the coupling belt 2 is waited for to form a gap between the ball 3 and the coupling portion 4 or the belt member 5. However, the ball 3 can freely rotate.

According to the ball chain 1 of the present embodiment having the above-described structure, the connecting belt 2 has the most space between the balls 3 adjacent to each other, that is, at the position where the connecting portion 4 is formed. Since the ball chain 1 has a constricted shape, it is possible to freely bend the ball chain 1 in any direction at such a position. For example, as shown in FIG. It is possible to freely bend not only in the a direction, but also in the arrow b direction between the belt members 5 and 5 adjacent to each other.

On the other hand, since the ball chain 1 is constricted at the formation position of each connecting portion 4 as described above, even if the ball chain 1 is twisted in the direction of arrow c in FIG. The connecting belt 2 can follow this and deform without difficulty. Further, even if the joint belt 2 is deformed following such twisting, the movement of the ball 3 is restrained from four directions by the four belt-shaped belt members 5, so that the ball 3 is connected to the joint belt 2. There is no fear of falling out.

FIG. 3 shows an example of a linear guide device incorporating this ball chain. In the figure, reference numeral 10 is a track rail disposed on a fixed part such as a bed of a machine tool, reference numeral 20 is a ball endless track in which the ball chain 1 is incorporated, and a movable body such as a table is a track rail. A slider that guides along 10,
Reference numeral 3 is a ball which rolls while applying a load between the track rail 10 and the slider 20 and which infinitely circulates in the slider 20.

First, the track rail 10 is formed into a substantially rectangular cross section, and Gothic arch-shaped ball rolling grooves 11 are formed on both sides of the track rail 10 in the longitudinal direction (the direction perpendicular to the plane of FIG. 2). Is formed. Bolt mounting holes 12 are formed in the track rail 1 at appropriate intervals in the longitudinal direction, and the track rail 10 is fixed to a fixing portion by a fixing bolt (not shown) inserted into the bolt mounting hole 12. .

The slider 20 has a horizontal portion 20a having a mounting surface 21 for a movable body and a pair of skirt portions 20b, 20b hanging from the horizontal portion 20a. Skirt part 20b
A load rolling groove 23 in the shape of a Gothic arch is formed on the inner surface side of the rail so as to face the ball rolling groove 11 of the track rail 10. In addition, each skirt portion 20b is formed with a ball return hole 24 corresponding to each load rolling groove 23. The ball 3 released from the load after rolling in the load rolling groove 23 is completed.
Are rolling in the direction opposite to the rolling direction on the load rolling groove 23.

The slider 20 is manufactured by injection molding of synthetic resin. That is, the slider 20
Is a metal block body 2 formed by machining
5, the resin portion 22 is formed by injection molding, and the block main body 25 is a portion where mechanical strength is required, such as the movable body mounting surface 21 and the load rolling surface 23 of the ball 3 described above. On the other hand, parts such as the ball return hole 24 where mechanical strength is not important are formed of synthetic resin.
The weight of the slider 20 is reduced as much as possible.

FIG. 4 is a sectional view showing a ball endless track of a slider 20 incorporating the ball chain 1.
This endless track is completed by fixing the synthetic resin lid 30 to the front and rear end surfaces of the slider 20. That is, when the lid body 30 is fixed to the slicer 20, the ball guide portion 26 on the slider 20 side is fitted into the U-shaped groove 31 on the lid body 30 side to complete the U-shaped direction changing path 32. The conversion path 32 connects the load rolling surface 23 of the slider 20 and the ball return hole 24.

FIG. 5 is an enlarged view showing a rolling state of the ball on the endless track. Relief grooves 27, 27 are formed at the deepest portions of the ball rolling groove 11 and the load rolling groove 23, which are formed in a Gothic arch shape, respectively, and when the ball 3 rolls in these rolling grooves 23, 11. The belt member 5 of the ball chain 1 is housed in the escape groove 27. On the other hand, in the ball return hole 24 of the slider 20, four guide grooves 28 are formed along the longitudinal direction thereof, and the belt member 5 of the ball chain 1 in the unloaded state is formed.
Are guided by the guide groove 28, and meandering of the ball chain 1 inside the ball return hole 24 is prevented.

According to the linear guide device of the present embodiment having the above-mentioned structure, the slider 20 has the track rail 1
0, the ball 3 rolls on the load rolling groove 23 of the slider 20 and the ball rolling groove 11 of the track rail 10, and the ball chain 1 circulates inside the endless track formed on the slider 20. .

At this time, in the linear guide device of this embodiment,
As shown in FIG. 5, the load rolling groove 2 in the slider 20
The position where the ball return hole 24 is formed is slightly higher than the position where the ball return hole 24 is formed, and when the ball chain 1 of the present embodiment described above is circulated in the endless track, the ball chain 1 is moved in the endless track. In, the belt member 5 is bent in a direction irrelevant to the formation position.

At this time, since the ball chain 1 of the present embodiment adopts the structure which can be flexibly bent in any direction as described above, the load rolling groove 23 and the ball return hole 2 are used.
Even when 4 and 4 have the positional relationship shown in FIG. 5, they can be bent without difficulty and smooth circulation can be achieved in the endless track.

Next, FIG. 6 shows an example of a ball screw device incorporating the ball chain of this embodiment. In the figure, reference numeral 50 is a screw shaft in which a spiral ball rolling groove 51 is formed by a predetermined lead, and reference numeral 60 is provided with an endless track in which the ball chain 1 is incorporated and the ball 3
It is a nut member screwed to the screw shaft 50 through.

Here, the nut member 60 is made of a steel nut main body 62 having a flange 61 for fixing the nut member 60 and a composite fixed to the front and rear end surfaces of the nut main body 62. It is composed of a pair of lids 63, 63 made of resin.

On the inner diameter of the nut body 62, there is formed a spiral load rolling groove 64 facing the ball rolling groove 51 of the screw shaft 50, while a ball return parallel to the screw shaft 50 is formed. A hole 65 is provided. Further, as shown in FIG. 7, the lid 63 is formed with a direction change path 66 for guiding the ball 3 which has finished rolling in the load rolling groove 64 of the nut body 62 to the ball return hole 65. By fixing the lid 63 to the nut body 62, the endless track of the ball 3 is completed.

The ball rolling groove 51 of the screw shaft 50 is also used.
Also, the load rolling groove 64 of the nut body 62 is formed in a Gothic arch shape, and like the above-described linear guide device, an escape groove for accommodating the belt member 5 of the ball chain 1 is formed at the deepest portion of each groove. ing.

Further, in the direction changing path 66 of the lid 63 and the ball return hole 65 of the nut body 62, the belt member 5 of the ball chain 1 is also provided similarly to the above-described linear guide device.
4 guide grooves for guiding the ball chain 1 are formed along the longitudinal direction, and the ball chain 1 wound around the outer periphery of the screw shaft 50 is accommodated in the direction changing path 66 of the lid 63 in a predetermined posture. It is like this.

According to the ball screw device of this embodiment constructed as described above, when the screw shaft and the nut member rotate relative to each other, the balls 3 incorporated in the ball chain 1 are loaded by the nut member 60. Rolling groove 64 and screw shaft 50
The ball chain 1 rolls on the ball rolling groove 51, and the ball chain 1 circulates inside the endless track formed in the nut member 60.

At this time, in the ball screw device of this embodiment, since the ball chain 1 is spirally wound around the outer circumference of the screw shaft 50, the ball chain 1 is twisted in the endless track. Is circulating. Particularly, when the ball chain 1 enters the direction changing path 66 of the lid 63 from the outer circumference of the screw shaft 50, as shown in FIG. 7, the ball chain is forcibly twisted by about 90 ° to form the direction changing path. It is necessary to enter the ball chain, and the bending or twisting motion or twisting motion of the ball chain in the endless track is inevitably stronger than the circulation in the linear guide device described above.

However, since the ball chain 1 of this embodiment adopts the structure that it can be flexibly bent and twisted easily in any direction as described above, it is possible to smoothly circulate the endless track of the nut member. Therefore, it is possible to facilitate the circulation of the ball chain in the endless track.

Further, even if the ball chain is frequently bent or twisted, the ball chain of the present embodiment has the balls completely enclosed by the connecting belt. It does not fall off, and it is possible to prevent accidents such as the ball falling off the track.

[0038]

As described above, in the ball chain of the present invention, the connecting belt has a constricted shape between the balls adjacent to each other, and it is easy to bend flexibly in any direction. Since it has a structure that easily absorbs the twist acting on the ball chain, it can be freely bent or twisted when it is installed in a ball endless track such as a linear guide device or a ball screw device. The ball chain can be smoothly circulated in the endless track even in such a state of use.

Further, in the ball chain of the present invention, the balls incorporated therein are completely enclosed by the connecting belt, and even if the ball chain is greatly bent or twisted, Since it does not fall out of the connecting belt, by incorporating this ball chain in the ball endless track of a linear guide device, ball screw device, etc., the ball does not fall out of the endless track without using a ball cage. It is also possible to prevent

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a ball chain of the present invention.

2 is a II-II of the ball chain shown in FIG.
It is a line sectional view.

FIG. 3 is a sectional view showing an example of a linear guide device in which the ball chain of the present invention is incorporated.

FIG. 4 is a cross-sectional view showing a ball endless track of the linear guide device shown in FIG.

5 is a cross-sectional view showing a rolling state of the ball in the ball endless track shown in FIG.

FIG. 6 is a sectional view showing an example of a ball screw device in which the ball chain of the present invention is incorporated.

7 is an enlarged view of part C of the ball screw device shown in FIG.

FIG. 8 is a plan view showing a conventional ball chain.

FIG. 9 is a side view showing a conventional ball chain.

FIG. 10 is a sectional view showing a state in which a conventional ball chain is incorporated in an endless track of a linear guide device.

FIG. 11 is a schematic view illustrating a problem of circulation in a track of a conventional ball chain.

[Explanation of symbols]

1 ... Ball chain, 2 ... Connection belt, 3 ... Ball,
4 ... Connection part, 5 ... Belt member

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Claims (2)

(57) [Claims] 1. A ball chain comprising a plurality of balls arranged in a row at a predetermined interval and a connecting belt which holds the balls rotatably and connects adjacent balls to each other. Then, the connecting belt is only along the spherical surface of the ball.
Also, four balls formed in a strip shape along the arrangement direction of the balls
Between the belt member and the balls adjacent to each other
These balls contact each other and the four belt members
A ball chain comprising: a connecting portion for connecting and bundling, wherein the connecting body belt is formed in a shape narrower than an outer diameter of the ball in the connecting portion . 2. The connecting belt has a spherical surface of each ball
The ball chain according to claim 1, wherein the belt members are arranged so as to be equally divided.