JPH0620894Y2 - Lightweight linear guide device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a lightweight linear guide device formed by forming a steel plate or the like into a predetermined shape.

[Conventional technology]

As a conventional lightweight type linear guide device, for example, there is one disclosed in Japanese Patent Publication No. 62-45413. This is a bed with a U-shaped cross section (guide rail)
The table and the table (slider) face each other with their bottoms facing each other, and the table is placed in the bed. A row of raceway grooves (ball rolling grooves) is formed in the longitudinal direction of the overlapping side surfaces, and balls are assembled in this raceway groove. In the direct acting bearing to be attached, a pair of ball unloaded circulation paths formed in the table are formed by a single member in the left-right direction and by two members in the up-down direction.

[Problems to be solved by the device]

However, in such a conventional light weight type linear guide device, since the ball rolling groove is formed in only one row on one side, the ball rolling groove is removed when preload is applied to eliminate the backlash. It is general that the moving groove has a Gothic arch shape and the contact with the ball is four-point contact. In this case, contact ellipses are generated at the four places due to contact between the ball and the ball rolling groove, and the ball rolling In this case, differential sliding is involved and the sliding resistance becomes larger than that in the case of simple rolling resistance. In applications such as machine tools that operate under heavy load, differential slippage is rather useful because it provides appropriate vibration damping properties, but since the drive becomes larger due to the increase in resistance, computer peripheral devices and office equipment This is not desirable in light load applications where downsizing of the entire device is required.

Further, when the ball is restrained at four points in this way, the preload changes greatly even with a slight dimensional change. Therefore, it was difficult to give an appropriate value of preload.

The present invention has been made by paying attention to such a conventional problem, and by making the number and arrangement of the ball rolling grooves such that the differential slip hardly occurs, the size is small and the backlash is small. It is an object of the present invention to provide a lightweight linear guide device having high rigidity and high accuracy.

[Means for Solving the Problems]

In order to achieve the above object, the present invention has a guide rail which has a substantially U-shaped cross section and is extended with axial ball rolling grooves at symmetrical positions on both inner side surfaces. A slider body fitted so as to be movable in the axial direction through rolling of a large number of balls, the slider body having ball rolling grooves opposite to the ball rolling grooves of the guide rail on both side surfaces. And a ball circulating member having a ball circulating path inside which is fitted to the slider body and communicates with the ball rolling groove inside, in a lightweight linear guide device, wherein the ball rolling groove of the guide rail is , Two rows of ball rolling grooves of the slider body facing each other are formed on one side, and the upper and lower intervals of each ball rolling groove are slightly changed to preload the balls at two points and to circulate the balls. Member to upper member And a lower member and an intermediate member sandwiched between the upper and lower members, and a pair of welding projections is provided on the upper surface and the lower surface of the intermediate member, and the upper welding projection is an upper member. It is sandwiched and welded to the slider body, and the lower welding projection is welded to the lower member.

[Action]

Opposing ball rolling grooves are in two rows on one side and are slightly offset vertically. Thus, even if a preload is applied to the balls in the groove to remove the backlash, each groove has two-point contact, and the differential slip is much smaller than that in the conventional four-point contact. Therefore, the drive motor may have a small capacity and can be downsized.

Further, the rigidity with respect to the compressive load from above is substantially the same, which improves the accuracy.

Furthermore, the ball circulation member is composed of the upper, middle and lower members,
These three members are integrally welded to the slider body via welding protrusions provided on the middle member. Therefore, it is possible to fix the above three members with dimensional accuracy more quickly than to fix them with bolts, rivets, and the like, and moreover, it is lightweight.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 to 7 show an embodiment of the present invention.

The guide rail 1 has a substantially U-shaped cross section with the opening facing upward, and two rows are arranged on one side at symmetrical positions on both inner side surfaces 1a thereof.
It has axial ball rolling grooves 2A and 2B and is extended in the axial direction. The cross-sectional shape of each ball rolling groove 2A, 2B is a so-called Gothic arch-shaped groove formed in a V shape with two arcuate surfaces having the same curvature but different centers.

Overhangs 1A projecting in the axial direction are formed at both front and rear ends of the bottom surface 1b of the guide rail, and countersink holes 4 for inserting countersunk screws for fixing the guide rail 1 to the base are formed therein. .

A slider 5 is loosely fitted inside the guide rail 1 so as to be axially movable through rolling of a large number of balls 9. The slider 5 is composed of a slider body 6 having a substantially inverted U-shaped cross section with an opening facing downward, and a synthetic resin ball circulating member 7 fitted into the slider body 6.

On the outer surface of the side plate portion 6A of the slider body 6, ball rolling grooves 8A, 8B formed of Gothic arch-shaped grooves facing the ball rolling grooves 2A, 2B on the inner surface of the guide rail are extended in the axial direction. Has been formed. The groove spacing (A) between the ball rolling grooves 8A and 8B of the slider body 6 is equal to the guide rail 1
A> B, which is slightly larger than that of the ball rolling grooves 2A and 2B (B). This allows the ball and groove to
It is a point contact. Further, the intersection point Q of the contact line approaches the center line of the guide rail 1 and a slight self-centering property becomes possible (see FIG. 7).

The ball circulation member 7 is configured by vertically stacking three members made of a synthetic resin molded product and integrally coupled to the slider body 6. That is, the thin plate-shaped upper member 7A, the thick plate-shaped lower member 7C, and the middle member 7 sandwiched between these upper and lower members.
B is made up of three members, and the upper and lower surfaces of the middle member 7B are axially spaced from each other, and two pieces are provided at both ends to form a pair of upper welding projections 1
0 and a pair of lower welding projections 11 are also provided. On the other hand, the upper member 7A is provided with an insertion hole 12 corresponding to the upper welding projection 10. Further, the lower member 7C is provided with an insertion hole 14 having a spot facing 13 corresponding to the lower welding projection 11. Then, after the lower welding projection 11 is inserted into the insertion hole 14 of the lower member 7C,
The terminal is welded in the spot facing 13. The upper welding projection 10 penetrates through the insertion hole 12 of the upper member 7A and is further inserted into an insertion hole 16 having a spot facing 15 formed in the slider body 6, and the end thereof is welded inside the spot facing 15. Thus, the upper member 7A, the middle member 7B, and the lower member 7C are integrally coupled to the slider body 6 via the upper welding protrusion 10 and the lower welding protrusion 11. Both side surfaces of the slider body 6 are inserted into the notches 17 provided on the left and right sides of the upper, middle, and lower three members 7A, 7B, 7C, respectively.

Inside the ball circulation member 7 thus integrated, a pair of left and right ball circulation paths are horizontally arranged in the figure.
The pair is formed symmetrically in the vertical and horizontal directions.

The upper ball circulation path includes a ball rolling groove 2A on the side surface of the guide rail and a ball rolling groove 8A on the slider body which faces the ball rolling groove 2A.
A ball return passage 21A formed of a square hole parallel to the ball rolling passage 20A, and the ball rolling passage 20A
And a semi-doughnut-shaped curved path 22A that connects the and. The lower ball circulation path is a ball return path 21B formed of a square hole parallel to the ball rolling path 20B formed by the ball rolling groove 2B on the side surface of the guide rail and the ball rolling groove 8B of the slider body facing the ball rolling groove 2B. , And a semi-doughnut-shaped curved path 22B that connects this with the ball rolling path 20B.

At the ends of the semi-doughnut-shaped curved paths 22A and 22B,
The scooping protrusion 23 for scooping up the ball B smoothly from the ball rolling paths 20A and 20B has a ball rolling groove 2A.
Alternatively, it is formed close to the groove bottom of 2B.

Reference numeral 24 is a screw hole for mounting the movable member, which is formed at two central locations on the slider body 6.

Next, the operation will be described.

The slider 5 is moved in the axial direction of the guide rail 1 by driving a not-shown movable member attached to the slider 5.
Then, the ball 9 in the ball rolling path 20A (20B)
Moves while rolling in a direction (rear side) opposite to the moving direction of the slider 5 with respect to the slider 5, and makes a U-turn in the semi-doughnut-shaped curved path 22A (22B) on one end side to make a ball return path 2
The circulation is repeated by entering 1A (21B), making a U-turn again in the semi-doughnut-shaped curved path on the other end side, and returning to the ball rolling path 20A (20B).

Since the ball 9 is preloaded, there is no backlash. Therefore, the slider 5 can move extremely smoothly and quietly.

The ball 9 rolling on the ball rolling path 20A (20B)
Is a two-point contact with the groove surfaces of the ball rolling grooves 2A (2B) and 8A (8B), the differential slip due to the contact ellipse is smaller than the conventional four-point contact, so the sliding resistance of the slider 5 is small. Is also small. Therefore, the required output of the table driving device (not shown) may be low, and the entire device can be downsized.

Moreover, since a compressive load from above is received through the upper and lower two rows of balls, it is possible to easily bear a large load.

The ball circulating member 7 of this embodiment is composed of synthetic resin upper, middle, and lower three members, and these three members are attached to the slider body 6 via the welding projections 10 and 11 provided on the intermediate member 3B. Since the structure is integrally welded, the above 3
Compared to fixing members with bolts or rivets, etc., they can be fixed more quickly with better dimensional accuracy and are lighter in weight.

The groove spacing may be opposite to that in the above embodiment. That is, the groove spacing (A) between the ball rolling grooves 8A and 8B of the slider body 6 is slightly smaller than that (B) of the ball rolling grooves 2A and 2B of the guide rail 1 and A <
By setting B, the ball and the groove are in contact with each other at two points, but in that case, the intersection Q of the contact lines is separated from the center line of the guide rail 1 and high rigidity against a moment load is exhibited (eighth embodiment). See figure).

[Effect of device]

As described above, according to the present invention, the ball rolling groove of the guide rail and the ball rolling groove of the slider body facing the guide rail are slightly vertically displaced to preload the ball and the ball that opposes each other. Two rows of rolling grooves were formed on one side. Therefore, it is possible to prevent large differential slippage, to be small in size, to have no backlash, and to have high rigidity, so that it is possible to provide a highly accurate lightweight linear guide device.

In addition, the ball circulation member has a structure in which the upper, middle, and lower three members are integrally welded to the slider body through the welding projections provided on the intermediate member. Therefore, the above three members are bolted or riveted. It has better dimensional accuracy than fixing and can be fixed quickly, and it is lightweight.

[Brief description of drawings]

1 to 8 show an embodiment of the present invention, FIG. 1 is a front view showing a cross section of a main portion, FIG. 2 is a perspective view of a slider body, and FIG. 3 is an upper member of a ball circulating member. FIG. 4 is a plan view of the lower member of the ball circulating member, FIG. 5 is a plan view of the middle member of the ball circulating member, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5, and FIG. FIG. 8 is an enlarged view of the groove shape of the ball rolling groove, and FIG. 8 is an enlarged view of another groove shape of the ball rolling groove. 1 is a guide rail, 2A, 2B, 8A and 8B are ball rolling grooves, 5 is a slider, 6 is a slider body, 7 is a ball circulating member, 7A is an upper member, 7B is an intermediate member, and 7C is a lower member.
0 and 11 are projections for welding, and 9 is a ball.

Claims (1)

[Scope of utility model registration request] 1. A guide rail having a substantially U-shaped cross section and extended with axial ball rolling grooves at symmetrical positions on both inner side surfaces, and rolling of a large number of balls in the guide rail. A slider that is fitted so as to be movable in the axial direction via a slider body, the slider body having a ball rolling groove facing the ball rolling groove of the guide rail on both side surfaces, and the slider body. In a lightweight linear guide device, which is integrally combined with a ball circulating member having a ball circulating path that is fitted and communicates with the ball rolling groove, a ball rolling groove of the guide rail and a slider facing the ball rolling groove. The ball rolling groove of the main body is formed in two rows on each side, and the upper and lower sides of each ball rolling groove are slightly changed to preload the ball at two points, and the ball circulating member is connected to the upper member and the lower member. The members and the ones above and below It is composed of three members, that is, a middle member sandwiched by members, and a pair of welding projections is provided on the upper surface and the lower surface of the middle member. The light-weight linear guide device is characterized in that the lower welding projection is welded to the lower member.