JPH04366017A - Straightly moving type guide device - Google Patents

Abstract

PURPOSE:To prevent straight movement from being ruined and also prevent vibration from producing on a moving body, to facilitate the forming operation of a ball guide groove. CONSTITUTION:A load reducing part for reducing load on a ball 16 gradually toward a reverse way is provided at both ends of a ball guide groove 7 of a moving body 2 which is mounted on a linear guide rail 1 and moved. At the load reducing part, a curvature at the arc section of the ball guide groove 7 of the moving body 2 is made equal to that at the other sections. Then a line B made by connecting the centers of the curvatures at arc sections of the ball guide grooves 7 of the moving body 2 at the load reducing part is moved gradually close to a line A made by connecting the centers of the curvatures at arc sections of the ball guide grooves 5 of the guide rail 1 toward the reverse way.

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, for example, to linearly move a table of a machine tool, and more particularly, to a linear guide rail and a linear guide rail.
The present invention relates to a linear guide device comprising a moving body having a generally inverted U-shape in cross section and moving across a guide rail.

[0002] In this specification, the terms "front and rear" and "left and right" refer to the moving direction of the moving body.

0003

[Prior Art and Problems to be Solved by the Invention] Conventionally, this type of linear guide device has been designed with circles on both the left and right sides of the guide rail and on the surfaces facing the left and right sides of the guide rail in the leg-shaped portions on both the left and right sides of the moving body. A ball guide groove having an arc-shaped portion is formed, a ball outward path is formed by both ball guide grooves, a ball return path is formed in each leg-shaped portion on both left and right sides of the moving body, and an end of the ball outward path and an end of the ball return path are formed. are connected by reversing paths formed at both front and rear ends of the moving body to form a ball circulation path, and a plurality of balls that roll between the moving body and the guide rail are enclosed in the ball circulation path of the moving body. The balls on the ball outward path in each ball circulation path are in point contact with the arcuate portions of both ball guide grooves, respectively, and a line connecting the centers of curvature of the ball guide grooves of the moving body is formed. However, it is known that the ball guide groove is a straight line parallel to a line connecting the centers of curvature of the ball guide groove of the guide rail. Since the ball makes point contact with the arcuate portions of both grooves, it goes without saying that the line connecting the centers of curvature of the ball guide grooves of the moving body is the line connecting the centers of curvature of the ball guide grooves of the guide rail. It is located closer to the guide rail. Further, in the forward path of the ball, a preload is applied to the ball in a direction connecting the contact points to both ball guide surfaces.

[0004] In such a direct-acting guide device, the ball outward path is a loaded area, and the ball return path and ball reverse path are non-loaded areas. In the load zone, the ball and the arcuate portions of both grooves elastically approach each other due to the load, and the ball is elastically deformed at the contact portion. Further, in the non-load zone, a gap exists between the ball and the ball so that the ball can pass freely, and the ball is not deformed. Therefore, when the ball enters the non-load zone from the loaded zone, the load on the ball suddenly drops to 0, and when the ball enters the loaded zone from the non-load zone, a large load is suddenly applied to the ball. In either case, the ball deforms rapidly. As a result, even if the balls are under a constant load, the number of balls receiving the load changes rapidly when the balls move between the loaded and non-loaded zones.
There was a problem in that the straightness was impaired and vibrations were generated in the moving body.

[0005] Conventionally, the ball guide groove of the movable body is provided with an inclined portion in the arcuate portion at both the front and rear ends thereof, which is inclined outward in the left-right direction toward the reversing path and gradually reduces the load on the ball. was forming. That is, in addition to cutting or grinding the moving body to form the ball guide groove, both ends of the ball guide groove are chamfered to form sloped portions.

[0006] However, this has the problem that the work becomes troublesome.

An object of the present invention is to provide a direct-acting guide device that solves the above problems.

[0008]

[Means for Solving the Problems] A direct-acting guide device according to the present invention includes a linear guide rail and a moving body having a substantially inverted U-shape in cross section that moves astride the guide rail. Ball guide grooves each having an arcuate portion are formed on both side surfaces of the moving body and on the surfaces of the leg-like portions on both sides of the moving body that are opposite to both side faces of the guide rail. A ball return path is formed in each of the leg-like portions on both sides, and an end of the ball outward path and an end of the ball return path are connected by a reversal path formed at both ends of the moving body to form a ball circulation path,
A plurality of balls rolling between the movable body and the guide rail are enclosed in the ball circulation path of the moving body, and the balls on the ball outward path in each ball circulation path move between the ball guide grooves and the ball guide rails. In a direct-acting guide device that is configured to make point contact with the arcuate portion, load reducing portions are provided at both ends of the ball guide groove of the movable body to gradually reduce the load on the ball toward the reversal path, The curvature of the arc-shaped part of the ball guide groove of the moving body in the load reduction part is made equal to the curvature of the other parts, and the line connecting the centers of the curvatures extends toward the ball guide groove of the guide rail toward the reversing path. The curve gradually approaches a line connecting the centers of curvature of the arcuate portions.

In the above linear guide device, a line connecting the center of curvature of the circular arc portion that makes point contact with the ball of the ball guide groove of the movable body in the load reducing section extends from the line and reaches a maximum in the cross section. The center of curvature of the arc-shaped part of the ball guide groove of the guide rail that makes point contact with the ball is located on a line that passes through a point away from the straight line connecting the contact points of the ball and the arc-shaped parts of both ball guide grooves in the load area. It is preferable that by displacing in a range closer to the guide rail than the line connecting the lines, the line gradually approaches the line connecting the centers of the guide rails toward the reversal path.

[0010] In the above, it is preferable that the line extending from the line connecting the centers of the movable body and passing through a point away from the straight line connecting the contact points at the maximum load portion be a continuous curve.

[0011] It is preferable that the line connecting the centers on the movable body side in the load reducing section pass through the line connecting the centers on the guide rail side in a cross section and be displaced in the same direction as the reversal path.

The line connecting the centers of the moving body is farthest from the line connecting the centers of the guide rails at the central part of the moving body in the longitudinal direction, and gradually approaches both ends in the longitudinal direction. It is better to have

Two upper and lower ball circulation paths are formed on the left and right sides of the guide rail, and a straight line connects the contact points of the ball with the arc-shaped portion of the ball guide groove that forms the ball outgoing path of the left and right ball circulation paths. It is preferable that the lines intersect at the outer sides of the ball outward path in the left-right direction, and that the lines connecting the centers of both ball guide grooves on the movable body side in the load reducing section are displaced in a direction toward each other.

Two upper and lower ball circulation paths are formed on both the left and right sides of the guide rail, and a straight line connects the contact points of the ball with the arc-shaped portion of the ball guide groove that forms the ball outgoing path of the left and right ball circulation paths. It is preferable that the lines intersect on the inner side of the ball outward path in the left-right direction, and that the lines connecting the centers of both ball guide grooves on the movable body side in the load reducing section are displaced in directions away from each other.

[0015]

[Function] Provided at both ends of the ball guide groove of the moving body,
In addition, a line connecting the centers of curvature of the arcuate portions of the ball guide groove in the load reducing portion that gradually reduces the load on the ball toward the reversal path is a line that connects the centers of curvature of the arcuate portion of the ball guide groove of the guide rail toward the reversal path. Since the distance between the contact points of the ball with both ball guide grooves gradually increases toward the reversal path in the load reducing portion, the distance between the contact points of the ball with both ball guide grooves gradually increases. therefore,
The load that the ball receives also gradually decreases.

Further, the curvature of the arcuate portion of the ball guide groove of the moving body in the load reducing portion provided at both ends of the ball guide groove of the moving body is made equal to the curvature of other parts, and the curvature is If the curve connecting the centers of the ball guide groove of the guide rail gradually approaches the line connecting the centers of curvature of the arc-shaped portion of the ball guide groove of the guide rail, for example, the ball guide groove can be formed on the moving body using an NC machine tool. During the formation, the load reduction section can be formed at the same time.

The line connecting the centers of the ball guide grooves of the movable body in the load reducing section is displaced on a line extending from the line and passing through a point away from the straight line connecting the contact points in the maximum load section in the cross section. By doing this, the ball guide grooves of each ball and the ball guide groove of the moving body gradually approach the line connecting the centers of the ball guide grooves of the guide rail toward the reversal path. The points of contact with the arcuate portion of the balls gradually differ, and the directions connecting the contact points also gradually differ, causing the direction of the preload applied to each ball to differ. Therefore, the rigidity and load capacity are increased when a load is applied in a direction other than the straight line connecting the contact points between the ball and the arcuate portions of both ball guide grooves at the maximum load portion, and vibration generation due to external loads is increased. can be suppressed.

When the line connecting the centers of the moving body passes through the line connecting the centers on the guide rail side in the cross section and is displaced in the same direction as the reversal path, the ball on the forward path immediately before entering the reversal path. In this case, the resistance to the reversing motion becomes small, and the ball easily enters the reversing path smoothly. Conversely, when the ball moves from the reverse path to the forward path, it becomes easier for the ball to enter the forward path.

Two upper and lower ball circulation paths are formed on both the left and right sides of the guide rail, and a straight line connects the contact points of the ball with the arc-shaped portion of the ball guide groove that forms the ball outgoing path of the left and right ball circulation paths. are made to intersect on the outer side of the ball's forward path in the left and right direction, and when the lines connecting the centers of both ball guide grooves on the moving body side in the load reducing section move toward each other, the ball on the reverse path of the moving body This prevents the ball from hitting the thick part of the ball scoop formed near the part connected to the outgoing path and damaging the thin part.

Conversely, the straight lines connecting the contact points of the ball with the arcuate portions of the ball guide grooves forming the ball outward paths of the left and right ball circulation paths intersect at the inside of the ball outward paths in the left and right direction, respectively. The line connecting the centers of both ball guide grooves on the moving body side in the load reducing section is
The same applies to the case where they are displaced in directions away from each other.

The line connecting the centers of the moving body is farthest from the line connecting the centers of the guide rails at the center of the moving body in the longitudinal direction, and gradually approaches both ends in the longitudinal direction. When the ball is in contact with both ball guide grooves, the distance between the contact points of the ball is smallest at the center in the front-rear direction and gradually increases toward both ends in the front-rear direction. It is smallest at the center in the front-rear direction on the outward journey, and gradually increases toward both ends in the front-rear direction. Therefore, for example, when assembling a moving object on the table of a machine tool, an installation error may occur and the object may be installed in a rotated state around a vertical axis or a horizontal axis extending in the horizontal direction, or a minute geometric error may occur on the mounting surface. In this case, the moving object has a moment around an axis perpendicular to the moving direction of the moving object, that is, a moment around a vertical line extending in the vertical direction (so-called yawing moment), and a moment around a horizontal line extending in the horizontal direction. Even if a moment (so-called pitching moment) acts, the ball is prevented from receiving an excessive load at the end of the ball guide groove of the moving body, and the ball can move smoothly. As a result, it becomes easier to obtain smooth operation of the moving body, and its lifespan is also improved.

[0022]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same functional parts and components are given the same reference numerals.

Embodiment 1 This embodiment is shown in FIGS. 1 to 6, and is a direct-acting guide device in which one row of ball circulation paths is provided on each side of a guide rail.

FIG. 1 shows the overall structure of a direct-acting guide device of the present invention, and FIGS. 2 to 6 show each part thereof in enlarged scale.

In FIG. 1, the linear guide device consists of a linear guide rail (1) and a moving body (2) having a substantially inverted U-shape in cross section and moving astride the guide rail (1). Become.

A row of arcuate ball guide grooves (5) are formed on both left and right side surfaces of the guide rail (1). A line (A) connecting the centers of curvature of the ball guide groove (5) of the guide rail (1) is a straight line extending in the front-rear direction (see FIG. 2).

[0027] The leg-shaped portions (2) on both the left and right sides of the moving body (2)
Arc-shaped ball guide grooves ( 7
) is formed. A ball outgoing path (9) is formed by the ball guide groove (5) of the guide rail (1) and the ball guide groove (7) of the moving body (2). Further, one hole-shaped ball return path (11) is formed in each leg-shaped portion (2a) on both sides of the moving body (2). Then, the end of the ball outward path (9) and the end of the ball return path (1
1) is connected to the end of the moving body (2) by a reversing path (13) formed at both ends of the moving body (2), thereby forming an endless ball circulation path (1).
5) is formed. In each ball circulation path (15),
A plurality of balls (16) are enclosed. The balls (16) of the ball outward path (9) in each ball circulation path (15) are connected to both grooves (5) between both ball guide grooves (5) and (7).
(7) is in contact with the groove surface at one point (P) and one point (Q), respectively (see FIG. 3).

As shown in FIG. 3, the straight line (L0) connecting both points (P) and (Q) of the forward path of the ball (9) is horizontal in the cross section. The ball outward path (9) in each ball circulation path (15) is a load zone, and the ball return path (11) and reverse path (13) are a non-load zone.

Ball guide groove (7) of moving body (2)
At both front and rear ends of the ball (
16) is provided. The moving body (
2) The curvature of the ball guide groove (7) is made equal to the curvature of the remaining intermediate portion (7b). In addition, the line (B) connecting the centers of curvature of the ball guide groove (7) is the same as the line (A) connecting the centers of curvature of the ball guide groove (5) of the guide rail (1) in the intermediate portion (7b). They are parallel straight lines, and gradually approach the line (A) connecting the centers of curvature of the ball guide groove (5) of the guide rail (1) in the load reduction section (7a) (see Figure 2). . Ball guide groove (7) in moving body (2)
The line (B) connecting the centers of curvature of the load reducing part (7a) is the contact point between the ball (16) and both ball guide grooves (5) and (7), as shown by the arrow (E) in Figure 3. (P) (Q)
A line connecting the center of curvature of the ball guide groove (5) in the guide rail (1) on the straight line (L0) connecting them (
A) may be gradually approached, as shown by arrow (F) in the same figure, by displacing in the horizontal direction, or as shown by arrow (G) in the same figure. , may be gradually approached by vertical displacement. Also, not limited to these directions, a line connecting the centers (A)
If the displacement is within a circle (H) with the center at Even if it is displaced to , it will approach the line (A) connecting the centers.

Next, a line (B) connecting the center of curvature of the load reducing portion (7a) of the ball guide groove (7) in the movable body (2) connects the ball (16) and both ball guide grooves (5).
) (7) The contact point (P) (Q) is connected with the straight line (L
0) The case where the upper part gradually approaches the line (A) connecting the center of curvature of the ball guide groove (5) in the guide rail (1) will be explained. Now, consider the case where the ball (16) on the forward path (9) moves to the reverse path (13). In the middle part (7b) of the ball guide groove (7), as shown in Fig. 4, a line (B) connecting the centers of curvature
The distance between the ball (16) and the line (A) connecting the center of curvature of the ball guide groove (5) of the guide rail (1) is
) and the contact points (P) and (Q) with the groove surfaces of both grooves (5) and (7). The distance between the contact points (P) and (Q) is in the smallest state. Therefore, a large load is applied to the ball (16), and both grooves (5) (
7) are elastically approaching each other under load. When this ball (16) enters the load reduction part (7a), in a part near the middle part (7b), a line (B) connecting the centers of curvature of the ball guide groove (7)
) is a line (A) that connects the above straight line (L0) to the center of curvature of the ball guide groove (5) of the guide rail (1).
, and the distance between both lines (A) and (B) is smaller than that in FIG. Therefore, the distance between the contact points (P) and (Q) to both grooves (5) and (7) becomes slightly larger, and the ball (
16) is also reduced, and the degree of elastic approach between the ball (16) and the groove surfaces of both grooves (5) and (7) is reduced. When the ball (16) reaches the end of the load reduction part (7a) on the reverse path (13) side, as shown in FIG. 6, the line (B) connecting the centers of curvature of the ball guide groove (7) is ,
The line (A) connecting the center of curvature of the ball guide groove (5) of the guide rail (1) on the straight line (L0) above is closer to the line (A), and the distance between both lines (A) and (B) is smaller than that in Figure 5. becomes smaller. Therefore, the contact point (P
) (Q) becomes larger, the load on the ball (16) becomes smaller, and the distance between the ball (16) and both grooves (
5) It almost no longer elastically approaches the groove surface of (7). In this state, the vehicle enters the reversal path (13), which is a non-load zone. In this way, while the ball (16) moves through the load reducing portion (7a) from the intermediate portion (7b) side to the reversing path (13), the load on the ball (16) gradually decreases. As a result, a sudden change in the number of balls (16) receiving a load is prevented, and displacement of the moving body (2) when the balls (16) move from a loaded area to a non-loaded area is prevented. Straight running performance will not be impaired. Moreover, the mobile object (2
) is suppressed from occurring in the moving body (2) due to its displacement.

When the ball (16) moves from the reversing path (13) to the forward ball path (9), contrary to the above, the load applied to the ball (16) gradually increases, so that the ball (16) This prevents sudden changes in the number of balls (
16) Moving body (2) when moving from a non-load area to a load area
) displacement is prevented, and straightness is not impaired. Moreover, the moving body (2) due to the displacement of the moving body (2)
The generation of vibrations is suppressed.

Note that the line (B) connecting the center of curvature of the load reducing portion (7a) of the ball guide groove (7) in the moving body (2) is the line (B) that connects the ball (16) and both ball guide grooves (5).
) (7) The contact point (P) (Q) is connected with the straight line (L
0) Even if the upper part does not gradually approach the line (A) connecting the centers of curvature of the ball guide groove (5) in the guide rail (1), but approaches in any other arbitrary direction as mentioned above, the above procedure will not apply. A similar effect can be obtained.

In the above embodiment, both ball guide grooves (5) and (7) each consist of one circular arc having one radius of curvature and a line connecting the centers, but the ball guide grooves have the same radius. It may be formed from two arcuate portions having curvatures, or it may be formed from two or more arcuate portions having different curvatures.

Embodiment 2 This embodiment is shown in FIGS. 7 to 16, and is a direct-acting guide device in which two rows of ball circulation paths, upper and lower, are provided on both sides of a guide rail.

[0035] Figures 7 to 7 show the direct-acting guide device in an assembled state.
In FIG. 14, the linear guide device consists of a linear guide rail (1) and a moving body (2) having a substantially inverted U-shape in cross section and moving astride the guide rail (1).

Shallow grooves (3) extending in the front-rear direction are formed on both left and right sides of the guide rail (1), and arc-shaped ball guide grooves (4) with equal curvature over the entire length are formed above and below the grooves (3). )(5) is formed. Ball guide groove (4) of guide rail (1) (
The line (A) connecting the centers of curvature in 5) is a straight line extending in the front-rear direction (see FIG. 11).

The leg-like portions (2) on both the left and right sides of the moving body (2)
On the surfaces facing the left and right sides of the guide rail (1) in a), there are two upper and lower arcuate ball guide grooves (6) (7) with equal curvature over the entire length facing the ball guide grooves (4) and (5), respectively. ) is formed. The ball guide grooves (4) (5) of the guide rail (1) and the moving body (
2) The ball guide grooves (6) and (7) form ball outward paths (8) and (9). Two upper and lower hole-shaped ball return paths (10 and 11) are formed in the leg-shaped portions (2a) on both sides of the moving body (2), respectively. Then, the ends of each ball outward path (8) (9) and each ball return path (10) (
11) are connected by reversing paths (12) and (13) formed at both front and rear ends of the movable body (2) to form endless ball circulation paths (14) and (15). The upper reversing path (12) slopes downward toward the outer side in the left-right direction, and the lower reversing path (13) slopes upward toward the outer side in the left-right direction. A plurality of balls (16) are enclosed in each ball circulation path (14) (15). Ball (1
6) The curvature of guide rail (1) and moving body (2)
) is larger than the curvature of the ball guide grooves (4), (5), (6), and (7), and each ball circulation path (14) (1
The ball (16) in the outgoing ball paths (8) and (9) in 5) is
Between both ball guide grooves (4) (5) and (6) (7), contact the groove surfaces of both grooves (4) (5) and (6) (7) at one point (P) and (Q), respectively. (See FIGS. 9 and 12).

In the cross section, as shown in FIG. 9, a straight line (L
) is a straight line (L) that slopes downward toward the outside in the left-right direction and connects both points (P) and (Q) of the ball's forward path (9) below.
slopes upward toward the outside in the left-right direction, and both lines (
L) intersect outside the ball outward paths (8) and (9) in the left and right direction. The ball outward path (8) (9) in each ball circulation path (14) (15) is the load area, and the ball return path (10
) (11) and reverse roads (12) and (13) are non-load areas.

As shown in FIGS. 10 and 11, balls (16) are provided at both front and rear ends of the ball guide grooves (6) and (7) of the movable body (2) toward the reversing paths (12) and (13).
Load reduction part (6a) (7a) that gradually reduces the load of
is provided. The line (B) connecting the centers of curvature of the ball guide grooves (6) and (7) is the load reducing part (6a) at both ends.
In the intermediate part (6b) and (7b) between (7a), it is a straight line parallel to the line (A) connecting the centers of curvature of the ball guide grooves (4) and (5) of the guide rail (1).
It is located closer to the guide rail (1) than the line (A). In addition, the line (B) of the upper ball guide groove (6) and the line (B) of the lower ball guide groove (7) are different from each other in the load reduction section (6a) (7a).
) so that the guide rails (1
) is gradually approaching the line (A) connecting the centers of curvature of ball guide grooves (4) and (5). In other words, the moving body (2
) The line (B) connecting the centers of curvature of the load reducing part (7a) of the lower ball guide groove (7) in A straight line (L) connecting the contact points (P) and (Q) at the end of the middle part (7b) of the extended load reducing part (7a)
A spiral continuous curve (S) passing through a point (R) far away from
By displacing the upper part upward in the range on the guide rail (1) side rather than the line (A) on the guide rail (1) side, it gradually approaches the line (A) toward the reversing path (13). . The load reducing part (6) of the upper ball guide groove (6)
In the opposite direction, the line (B) connecting the centers of curvature in a) is displaced downward in the range on the guide rail (1) side rather than the line (A) on the guide rail (1) side. It gradually approaches line (A) toward the reversal path (12). At the end of the reversing path (12) and (13), the line (B) is the line (A) on the guide rail (1) side.
A line (T) passing through and parallel to the reversal path (12) (13)
It's coming up. In addition, in the above explanation, the reference numerals of each part related to the upper ball circulation path (14) are as shown in FIGS. 10 and 1.
1, the symbols are attached after the corresponding parts of the lower ball circulation path (15).

The assembled moving body (2) has end cap portions (17) at both front and rear ends, and the remaining intermediate portion (18).
), and each of these parts (17) (18)
The legs (leg-like parts) (19) and (20) on both the left and right sides,
It consists of connecting parts (21) and (22) that connect the upper ends of the left and right legs (19) and (20).

Ball guide grooves (6) and (7) are formed on the rail (1) side of the legs (20) on both sides of the intermediate portion (18) of the movable body (2), that is, on the inside in the left-right direction, and the upper and lower grooves A retainer (23) is provided between (6) and (7). In addition, the grooves (
6) Hole-shaped return path (10) (11) on the outside of (7)
) is formed. A semicircle is formed between both ends of the intermediate portion (18) and the legs (19) on both sides of the end cap portion (17) to connect the ends of the outward paths (8) and (9) and the ends of the backward paths (10 and 11). Reversing paths (12) and (13) are formed.

As shown in FIG. 15, the moving body (2) is
2 end cap parts (17), central body part (2
4) and two cage members (25).

As shown in FIGS. 15 and 16, protrusions (corresponding to the grooves (3) of the rail (1)) are provided on the inner surfaces in the left-right direction of the legs (19) on both sides of the end cap portion (17). 26) are formed, and arcuate portions (27) corresponding to the ball guide grooves (4) and (5) of the rail (1) are formed above and below the protrusion (26). A groove (28) spanning the entire left and right width is formed on the front-rear inward surface of the legs (19) on both sides of the end cap portion (17), including the protrusion (26) and the arcuate portion (27). Under this groove (28), there is a protrusion (29) that protrudes inward in the front-rear direction.
) is formed. Note that the upper and lower side wall surfaces of the groove (28) are sloped surfaces that are slightly opened inward in the left-right direction, and are part of the reversal path (12) (13). Shallow oval recesses (30) are formed above and below the inward surface in the longitudinal direction of the bottom of the groove (28). The inner end in the left-right direction of the recess (30) extends to the arcuate portion (27) corresponding to the ball guide grooves (6) and (7), and the inner peripheral surface of the tip and the outer circumference of the arcuate portion (27) The part between the surfaces is a ball scooping part (31) that scoops up balls that have entered the reversal paths (12) and (13). The curvature of the outer peripheral surface of the rake portion (31) corresponds to the curvature of the ball guide grooves (6) and (7), and the curvature of the end of the recess (30) corresponds to the curvature of the ball (16). Moreover, the upper recess (30) is inclined downwardly toward the outer side in the left-right direction, and the lower recess (30)
) is inclined upward toward the outside in the left-right direction, so
The thickness of the rake portion (31) is the thickest on the protrusion (26) side, and gradually becomes thinner as it moves away from this side. A semicircular groove-shaped notch (32) is formed at the middle portion in the left-right direction of the inward surface of the protrusion (29) in the front-rear direction. In addition, a semicircular groove-shaped recess whose lower end extends into the groove (28) is formed in a portion above the groove (28) on the front-rear inward surface of the leg portion (19) on both sides of the end cap portion (17). (3
3) is formed.

The cage member (25) includes a horizontal plate-shaped portion (20a) forming the lower part of the legs (20) on both the left and right sides of the intermediate portion (18) of the movable body (2), and a lower return path (1).
1) A vertical plate-shaped portion (20b) constituting the outer side, a retainer (23), and semi-cylindrical guide members (34) at both front and rear ends.
) are integrally formed.

[0045] The vertical plate-like part (20b) is the horizontal plate-like part (
It is formed upward on the outer edge in the left-right direction of the vertical plate-like part (20b), and the column-like part (20
c) are integrally formed. The cage (23) has a vertical plate shape, and its front and rear ends are integrally connected to the columnar part (20c) by a connecting part (35), and the horizontal plate part (20a
) is located inside and above the inner edge in the left and right direction. The guide member (34) is a horizontal plate-shaped part (20a)
It is integrally formed on both the front and rear ends of the
Its lower part protrudes outward from the horizontal plate-shaped part (20a) in the front-rear direction. The guide member (34) has a cylindrical surface (34a) on the outer side in the front-rear direction, and a flat surface (34a) on the inner side in the front-rear direction.
4b). A vertically intermediate portion of the guide member (34) is integrally connected to a connecting portion (35). The flat surface (34b) of the guide member (34) is connected to the columnar part (2
0c) and is flush with the inner flat surface of the connecting portion (35) in the front-rear direction. The flat surface on the outer side in the longitudinal direction of the connecting part (35) is located on the outer side of the cylindrical surface (34a) of the guide member (34) and is flush with the flat surface on the outer side in the longitudinal direction of the columnar part (20c). . Between the left-right inner edge of the horizontal plate-shaped portion (20a) and the lower edge of the retainer (23),
A predetermined interval is provided. Horizontal plate-shaped part (20a)
A ball guide surface (36) is formed on the inner edge in the left-right direction. Ball guide surfaces (37) and (38) are also formed on both upper and lower edges of the cage (23), respectively. In addition, from the horizontal plate-like part (20a) to the vertical plate-like part (20b)
A ball guide surface (39) is also formed throughout. Further, ball guide surfaces (40) are formed on both upper and lower surfaces of the connecting portion (35). And the connecting part (35
) from the left and right sides of the guide member (34) on both the upper and lower sides of the guide member (34) to the outer side in the front and rear direction.
is surrounded by the cylindrical surface (34a) of the connecting portion (35), the ball guide surface (40) of the connecting portion (35), the left-right inner surface of the columnar portion (20c), and the left-right outer surface of the retainer (23), and is surrounded by the reversing path (12) ( 13) is formed.

[0046] The central body portion (24) is connected to the intermediate portion (18).
The core part (20d), which is obtained by removing the cage member (25) from the legs (20) on both sides of the cage member ( 2
5) Flat surfaces (34b) of the front and rear guide members (34)
slightly smaller than the mutual spacing of . Core part (20d)
Ball guide grooves (6) and (7) are formed on the inner surface in the left-right direction. The upper groove (6) of the core part (20d)
) A through hole (42) forming the return path (10) for the upper stage is formed in a slightly lower part on the outer side in the left and right direction of the lower stage groove (7), and a through hole (42) forming the return path (10) in the lower stage is formed in a slightly lower part on the outer side in the left and right direction of the lower stage groove (7). A groove (43) with open sides and bottom is formed to form a return path (11).

[0047] The main body part (24) and the cage member (25) have a core part (20d) of the main body part (24), a vertical plate-like part (20b) of the cage member (25), and a cage (23).
and front and rear guide members (34) and connecting portions (35
) It is assembled so that it fits into the space surrounded by. As a result, the lower surface of the core portion (20d) is aligned with the guide member (34).
), and both front and rear end surfaces of the core portion (20d) touch the front and rear guide members (3).
4) comes into contact with the flat surface (34b) on the inside of the connecting portion (35) in the front-rear direction. In addition, the outer portion of the core portion (20d) in the left-right direction fits between the front and rear columnar portions (20c), and the core portion (20d)
d) The lower surface of the portion projecting outward in the left-right direction from above the groove (43) is in close contact with the upper end surface of the vertical plate-shaped portion (20b). Then, the groove (43) on the lower side of the core part (20d)
), horizontal plate-like part (20a), and vertical plate-like part (20b)
The return path (11) of the lower stage is
) is formed. Further, the inner surface of the core portion (20d) in the left-right direction contacts the retainer (23).

In this state, the end cap portions (17) are attached to both ends of the main body portion (24) and the cage member (25).
) is installed. That is, the holder (23), the columnar part (20c) and the connecting part (35) of the cage member (25)
) is fitted into the groove (28) of the end cap part (17), and the flat surface of the columnar part (20c) and the connecting part (35) on the front and back outer side is fitted into the groove (28) of the end cap part (17).
). Thereby, the end surface of the connecting portion (21) of the end cap portion (17) comes into contact with the end surface of the main body portion (24). At this time, the lower part of the guide member (34) of the cage member (25) fits into the notch (31) of the protrusion (29) of the end cap part (17), and the upper part fits into the recess of the end cap part (17). (33) fits. An upper reversal path (12) is formed by the upper ball guide portion (41) and the upper recess (30) of the end cap portion (17). Further, a lower reversal path (13) is formed by the lower ball guide portion (41) and the lower recess (30) of the end cap portion (17).

When the movable body (2) moves back and forth along the guide rail (1), the balls (16) on the outward paths (8) and (9) of the circulation paths (14 and 15) move against the rail (1).
And the moving body (2) rolls on the ball guide grooves (4), (5), (6) and (7), and moves backward in the moving direction of the outward paths (8) and (9). For this reason, the outward journey (8) (9)
The ball (16) that was in the reversal path (
12) (13), the ball (16) that was on the reverse path (12) (13) enters the return path (10) (11) in order,
The ball (16) that was on the return path (10) (11) passes through the reversal path (12) (13) at the front end of the moving direction in order and returns to the outbound path (8).
Enter (9). In this way, the ball (16) is transferred to the ball circulation path (14) (1
5).

Now, the balls (
16) moves to the reversal path (12) and (13), the case where the ball goes to the lower right ball forward path (9) will be explained. Middle part (7b) of ball guide groove (7) of moving body (2)
As shown in Figure 12, the distance between the line (B) connecting the center of curvature of the ball guide groove (5) of the guide rail (1) and the line (A) connecting the center of curvature of the ball guide groove (5) of the guide rail (1) is It is largest on the straight line (L) connecting the contact points (P) and (Q) between the ball (16) and the groove surfaces of both grooves (5) and (7). The distance between the contact points (P) and (Q) to (7) is the smallest. The center (O) of the ball (16) is located at the midpoint between both lines (A) and (B) of the straight line (L). Therefore, a large load is applied to the ball (16), and the ball (16) and the groove surfaces of both grooves (5) and (7) elastically approach each other under the load.

This ball (16) is the load reducing part (7a)
When entering the line (B) of the moving body (2), as shown in Figure 13,
) approaches the line (A) of the guide rail (1) on the above curve (S), and the distance between both lines (A) and (B) is as shown in Figure 1.
It is smaller than 2. Also, both grooves of the ball (16) (
5) The contact point to (7) also changes to (P1) (Q1). Therefore, the contact point (P1) (Q
1) The distance between the contact points (P) and (Q) becomes slightly larger than the distance between the contact points (P) and (Q), and the load applied to the ball (16) becomes smaller, so that the distance between the ball (16) and both grooves (5) and (7) becomes smaller. The degree of elastic approach with the groove surface becomes smaller.

When the ball (16) reaches the end of the load reduction section (7a) on the reverse path (13) side, the line (B) of the moving body (2) changes from the curve (S) as shown in FIG. ) on the guide rail (1), and the distance between the two lines (A) and (B) becomes even smaller than in FIG. Further, the contact points of the ball (16) with both grooves (5) and (7) also change to (P2) and (Q2). In the cross section, the line (L) connecting both contact points (P2) (Q2) is the line (A)
It coincides with a line (T) that passes through and is parallel to the reversal path (13). Therefore, the contact point (P2
) (Q2) becomes even larger than the distance between the contact points (P1) (Q1), the load applied to the ball (16) becomes smaller, and the distance between the ball (16) and both grooves (5) (7) becomes larger.
) becomes less elastic in its approach to the groove surface. Additionally, the direction of the load applied to the ball (16) is initially at the intermediate portion (
Similar to 7b), it is tilted so that the right side is up with respect to the horizontal, but in the cross section, it gradually rotates to the right toward the reversal path (13), and finally the reversal path (13) becomes parallel to

In this state, the ball (16) enters the reversal path (13), which is a non-load area. In this way, the ball (16
) moves the load reducing part (7a) from the middle part (7b) side to the reversing path (13), the load on the ball (16) gradually decreases. As a result, displacement of the moving body (2) when the ball (16) moves from the loaded area to the non-loaded area is prevented, and the straightness is not impaired.

In addition, in the load reducing section (7a), the guide rail (1) of each ball (16) and the moving body (
2) The point of contact with the ball guide grooves (5) and (7) is (P
)(Q) to (P2)(Q2), and the contact points (P)(Q)(P1)(Q1)(P2)(Q2
) The direction in which the balls are connected gradually differs, and each ball (16
) will have a different direction of preload. Therefore, the rigidity and load capacity when a load is applied in a direction other than the straight line connecting the contact points (P) and (Q) between the ball (16) and both ball guide grooves (5) and (7) at the maximum load portion are calculated. At the same time, it is possible to suppress the occurrence of vibration due to external loads.

Regarding the ball (16) on the forward path, the movement resistance of the ball (16) heading toward the reversal path (12) (13) becomes smaller just before entering the reversal path (12) (13). , smooth ball movement becomes possible, and it becomes easier to enter the reversal path (12) (13).

Furthermore, the lines (A) and (B) connecting the centers of the ball guide grooves (5) and (7) of the guide rail (1) and the moving body (2) in the load reducing part (7a) are as shown above. When the moving object (2) is displaced in the direction approaching
The ball (16) hits the thick part of the ball scoop part (31) on the edge of the recess (30) on the lower side of the end cap part (17), that is, the part near the protrusion (26), This prevents damage to the thin portion of the rake portion (31), that is, the portion away from the protrusion (26).

When the ball (16) moves from the reversing path (13) to the forward ball path (9), contrary to the above, the load applied to the ball (16) gradually increases, so that the ball (16) Displacement of the moving body (2) when moving from a non-loaded area to a loaded area is prevented, and the straightness is not impaired. Moreover, the ball (16) is on the reverse path (1
3) makes it easier for the ball to enter the outward path (9).

The balls (16) of the other ball circulation paths (14, 15) are transferred from the ball outgoing path (8), (9) to the reversing path (12).
) (13) and vice versa, the same effect as described above can be obtained due to the presence of the load reducing portions (6a) and (7a).

Example 3 This example is shown in FIG. In FIG. 17, the ball guide grooves (4) forming the ball outgoing paths (8) and (9) of the left and right ball circulation paths (14) and (15)
(5) Contact point (P) of ball (16) on (6) (7)
(Q) The straight lines (L1) connecting them intersect inside the ball outward paths (8) and (9) in the left and right direction, respectively. Then, a line ( B)
The line (B) connecting the above-mentioned centers of the lower ball guide groove (6) and the lower ball guide groove (6) are in the direction away from each other, that is, in FIGS.
It gradually approaches the line (A) on the guide rail (1) side so that it is displaced in the opposite direction to that explained in 4.

The effect in this case is also similar to that in the second embodiment.

Example 4 This example is shown in FIG. In Fig. 18, the arcuate ball guide grooves (6) (7) of the moving body (2)
A line (B) connecting the centers of curvature of the ball guide groove (4) (
5) It is farthest from the line (A) connecting the centers of curvature, and has an arcuate shape with a small curvature so as to gradually approach both ends in the front and back direction. Therefore, the contact point (
The distance between P) and (Q) is smallest at the center in the front-rear direction and gradually increases toward both ends in the front-rear direction. The preload is greatest at the center in the longitudinal direction,
It gradually becomes smaller toward both ends in the front-rear direction. Line (B)
The method of approaching the line (A) is the same as in the case of the second embodiment. In addition, in the middle part excluding the predetermined length part at both the front and rear ends, the line (B) is the ball (1
6) and the contact point (P) between both ball guide grooves (5) and (7)
(Q) Straight line connecting them (L) Above the guide rail (1
) may gradually approach the line (A) connecting the centers of curvature of the ball guide grooves (4) and (5).

In this state, if a normal preload is applied to the ball (16) located at the center of each ball forward path (8) (9) in the front and rear direction, the ball (16) will be When a moment around a line or a moment around an axis extending in the left-right direction acts, other balls (16)
Although the load applied to the center ball (1
The preload applied to 6) should not be greater than that applied.

Other operations are the same as in Example 2 above.

[0064]

[Effects of the Invention] According to the direct-acting guide device of the present invention,
As mentioned above, in the load reduction section, the load applied to the balls gradually decreases toward the reversal path, so the number of balls receiving the load does not suddenly change, and the load area of the balls and the non-load area Displacement of the moving body when moving between zones is prevented, and straight-line performance is not impaired. Moreover, vibrations are prevented from occurring in the moving body. Also,
When forming the ball guide groove, the load reducing portion can be formed at the same time, which simplifies the work.

[Brief explanation of the drawing]

FIG. 1 is a horizontal sectional view showing a first embodiment of a direct-acting guide device of the present invention.

FIG. 2 is a partially enlarged view of FIG. 1;

FIG. 3 is an enlarged sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is a sectional view taken along the line V-V in FIG. 2;

FIG. 6 is a sectional view taken along the line VI-VI in FIG. 2;

FIG. 7 is a side view of a second embodiment of the linear guide device of the present invention in an assembled state.

FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7;

FIG. 9 is a partially enlarged view of FIG. 8;

FIG. 10 is a cross-sectional view taken along line XX in FIG. 8;

FIG. 11 is a partially enlarged view of FIG. 10;

12 is an enlarged sectional view taken along line XII-XII in FIG. 11. FIG.

13 is an enlarged sectional view taken along line XIII-XIII in FIG. 11. FIG.

14 is an enlarged sectional view taken along line XIV-XIV in FIG. 11. FIG.

FIG. 15 is an exploded perspective view, with some parts omitted, of the direct-acting guide device according to the second embodiment.

FIG. 16 is a view of the end cap portion of the direct-acting guide device of Example 2, viewed from inside in the front-rear direction.

FIG. 17 is a diagram corresponding to FIG. 9 showing a third embodiment of the direct-acting guide device of the present invention.

FIG. 18 is a diagram corresponding to FIG. 11 showing a fourth embodiment of the direct-acting guide device of the present invention.

[Explanation of symbols]

1 Guide rail 2
Moving body 2a Leg-shaped portion 4 Ball guide groove 5
Ball guide groove 6
Ball guide groove 7 Ball guide groove 7a Load reduction part 8 Ball outward path 9
Ball outward path 10 Ball return path 11 Ball return path 12 Ball reverse path 13
Ball reversal path 14 Ball circulation path 15 Ball circulation path 16
Ball A Line connecting the centers of curvature of the ball guide groove of the guide rail B Line connecting the centers of curvature of the ball guide groove of the moving body

Claims (7)

[Claims] Claim 1: Consisting of a linear guide rail and a moving body having an approximately inverted U-shaped cross section that moves astride the guide rail, the guides are provided on both sides of the guide rail and on leg-shaped portions on both sides of the moving body. Ball guide grooves each having an arcuate portion are formed on opposing sides of the rail, ball outward paths are formed by both ball guide grooves, and ball return paths are formed in the leg-shaped portions on both sides of the moving body, and the ball guide grooves are formed on opposite sides of the rail. The end of the forward path and the end of the ball return path are connected by a reversing path formed at both ends of the moving body to form a ball circulation path, and a ball circulation path between the moving body and the guide rail is formed in the ball circulation path of the moving body. A direct-acting guide in which a plurality of balls rolling are enclosed, and the balls on the outward path in each ball circulation path are in point contact with the arcuate portions of both ball guide grooves, respectively. In the device, load reducing portions are provided at both ends of the ball guide groove of the movable body to gradually reduce the load on the ball toward the reversal path, and the arcuate portion of the ball guide groove of the movable body in the load decreasing portion is provided at both ends of the ball guide groove of the movable body. The curvature is made equal to the curvature of other parts, and a line connecting the centers of the curvature gradually approaches a line connecting the centers of curvature of the arcuate portion of the ball guide groove of the guide rail toward the reversal path. A direct-acting guide device designed like this. 2. In a cross section, a line connecting the center of curvature of an arcuate portion that makes point contact with the ball of the ball guide groove of the moving body in the load reducing portion extends from the line and connects both sides of the ball in the maximum load portion. Guide the ball guide groove on a line that passes through a point away from the straight line connecting the points of contact with the arcuate portion of the ball guide groove than the line that connects the center of curvature of the arcuate portion that makes point contact with the ball in the ball guide groove of the guide rail. 2. The direct-acting guide device according to claim 1, wherein the direct-acting guide device is configured to gradually approach a line connecting the centers of the guide rails toward the reversal path by displacing within a range on the rail side. 3. The direct-acting guide according to claim 2, wherein a line extending from a line connecting the centers of the movable body and passing through a point away from a straight line connecting the contact points at the maximum load portion is a continuous curve. Device. 4. The line connecting the centers on the moving body side of the load reducing section passes through the line connecting the centers on the guide rail side in a cross section and is displaced in the same direction as the reversing path. Direct-acting guide device. 5. A line connecting the centers of the movable body is farthest from a line connecting the centers of the guide rail at the longitudinal center of the movable body, and gradually approaches both ends of the movable body in the longitudinal direction. 3. A direct acting guide device according to claim 2. 6. Two upper and lower ball circulation paths are formed on both the left and right sides of the guide rail, and the contact points of the balls with the arcuate portions of the ball guide grooves forming the ball outgoing paths of the left and right ball circulation paths are formed. 3. The straight line according to claim 2, wherein the connecting straight lines intersect at the outer sides of the ball forward path in the left-right direction, and the lines connecting the centers of both ball guide grooves on the moving body side in the load reducing part are displaced in a direction in which they approach each other. Dynamic guide device. 7. Two upper and lower ball circulation paths are formed on the left and right sides of the guide rail, and the points of contact of the balls with the arcuate portions of the ball guide grooves that form the ball outgoing paths of the left and right ball circulation paths are connected to each other. 3. The linear motion according to claim 2, wherein the connecting straight lines intersect on the inner side of the ball outward path in the left-right direction, and the lines connecting the centers of both ball guide grooves on the moving body side in the load reducing part are displaced in directions away from each other. Shape guide device.