JP5223713B2 - Linear motion guide device - Google Patents

Description

  The present invention relates to a linear motion guide device that is provided in a guide portion of a machine device such as a machine tool, a manufacturing apparatus, or a measuring instrument and linearly slides a moving object such as a table, and in particular, a roller as a rolling element. The present invention relates to a linear motion guide device using (rollers).

Of the linear guide devices having a guide rail and a slider that slides on the guide rail via the rolling element, the linear guide device using a roller as the rolling element has high rigidity and high load resistance. In particular, it is often used for machine tools.
In this type of linear motion guide device, the roller rolls between the track surface of the guide rail and the track surface of the slider on its load track while circulating infinitely in the roller circulation path. At this time, if a skew occurs in which the axis of the roller is not inclined to the rolling direction but is inclined obliquely, the roller and each track surface slip, and the sliding friction force causes the slider to slide on the guide rail. In addition to increasing sliding resistance and fluctuation when moving, wear is likely to occur on each raceway surface and the rolling surface of the roller, which causes a decrease in the life of the linear motion guide device. Therefore, in this type of linear motion guide device, a cage that guides the end surface of the roller is assembled to the inner surface of the slider body to prevent skew (see, for example, Patent Documents 1 and 2).

JP 2001-227541 A Japanese Patent Laid-Open No. 2005-256972

  However, in the technique described in Patent Document 1, for example, the cage has a pressing portion that presses both end faces of the roller, and the pressing portion receives a repeated load from the roller. Therefore, the function may not be maintained at an early stage due to wear of the pressing portion. Therefore, in the technique described in Patent Document 1, the effect of preventing skew is limited to the initial use of the linear motion guide device. Further, the pressing portion needs to press the roller with an appropriate pressing force so as not to hinder the rolling motion of the roller. Therefore, it is necessary to strictly manage the dimensional accuracy of the pressing portion, which increases the management cost.

  On the other hand, for example, the technique described in Patent Document 2 includes a slider having four rows of roller circulation paths. For example, as shown in the schematic diagram of the right half section of the slider body in FIG. In the cage 120 incorporated in the slider body 5, the cage 120 may be lifted from the slider body 5 due to a shape error when the cage 120 is manufactured or an installation error when the cage 120 is incorporated into the slider body 5 (FIG. 7). (See symbol F).

  In this case, as shown in the schematic diagram of the load trajectory in FIG. 8, as shown in FIG. 8 (a), the cage 120 is the one that was smoothly communicated with the direction changing path 14a. As shown in FIG. 7, out of the four rows of load tracks, the flanges (track collar surfaces) 140b for guiding the rollers 8 positioned on the upper side of the upper row and the lower side of the lower row, as shown in FIG. It will be located so that it may protrude toward the side (refer the code | symbol G in FIG. 7).

  Therefore, as shown in FIG. 8 (b), the end face of the roller 8 is pushed against the protruding track collar surface 140b, and the axis of the roller 8 is skewed obliquely without being orthogonal to the rolling direction. Cases arise. When the roller 8 is skewed, a slip occurs between the roller 8 and the load track. For this reason, the operation of the linear motion guide device is deteriorated, and the guide rail, the raceway surface of the slider, and the rolling surface of the roller are worn.

  Therefore, the present invention has been made paying attention to such problems, and an object thereof is to provide a linear motion guide device capable of preventing roller skew even when the cage is lifted from the slider body. It is said.

In order to solve the above problems, the present invention provides a guide rail having a total of four rows of rolling surfaces above and below the left and right side portions, and four rows of load tracks facing each of the rolling surfaces of the guide rail. A slider having a slider body having a total of four rows of rolling surfaces formed on the inner surface and a four-row roller circulation path for infinite circulation of a plurality of rollers interposed in the four rows of load tracks. And a pair of left and right holders assembled to the slider body so as to hold a plurality of rollers interposed in the four rows of load tracks, and the four rows of roller circulation paths circulate in the upper row. Linear guide having a roller arrangement formed such that the rotation axis of the roller moves downward as it moves away from the guide rail, and the rotation axis of the plurality of rollers circulating in the lower row moves upward as it moves away from the guide rail. The retainer has a track collar surface formed along an end surface of the roller circulating in each roller circulation path, and the upper and lower rows of rollers circulating in the upper row of the track collar surface. The track collar surface provided on the lower side of the roller that circulates the roller has first chamfered portions at both ends in the longitudinal direction, and the first chamfered portion of the roller that circulates each roller circulation path. The length in the longitudinal direction is longer than the depth in the direction facing the end surface, and the end of the rolling surface of the slider body is crowned, and the longitudinal direction of the first chamfered portion The length of the direction is characterized by being the same as the length of the crowning or longer than the length of the crowning .

  According to the linear motion guide device according to the present invention, even when the cage is lifted from the slider body, the track collar surface provided on the upper side of the roller circulating in the upper row and the lower side of the roller circulating in the lower row, First chamfered portions are formed at both ends in the longitudinal direction, and the length of the first chamfered portion is longer than the depth in the opposite direction to the end surface of the roller circulating in each roller circulation path. Therefore, the track collar surfaces positioned on the upper side of the upper row and the lower side of the lower row can be prevented from projecting toward the end surface of the roller rather than the end surface on the direction change path side. Therefore, the end face of the roller is not pushed against the protruding track collar surface, and the skew of the roller can be prevented.

Further, in the linear guide apparatus according to the present invention, the crowning at an end of the rolling surface of the slider body is subjected, the longitudinal length of the first chamfered portion is equal to the length of the crowning or longer than the length of the crowning, eliminating the unstable rollers located in a range of crowning is pushed by the trajectory flange surface, it is preferable in preventing the skew.

  As described above, according to the linear motion guide device according to the present invention, even when the cage is lifted from the slider body, the skew of the roller can be prevented.

It is a perspective view which shows the linear motion guide apparatus of one Embodiment of this invention. It is a right half sectional view in the ZZ section of FIG. It is the perspective view which looked at the holder | retainer of one Embodiment of this invention from the code | symbol A side of FIG. It is a schematic diagram explaining the load track | orbit of the linear motion guide apparatus of one Embodiment of this invention. It is a schematic diagram explaining the modification of the linear motion guide apparatus of one Embodiment of this invention. It is a schematic diagram explaining the modification of the linear motion guide apparatus of one Embodiment of this invention. It is a schematic diagram of the right half cross section of the slider main body of the conventional linear motion guide apparatus. It is a schematic diagram ((a), (b)) explaining the load track | orbit of the conventional linear motion guide apparatus.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate.
As shown in the perspective view of FIG. 1, the linear motion guide device 1 includes a guide rail 2 and a slider 3 straddling the guide rail 2.
The guide rail 2 is a long rod-like member having a substantially I-shaped cross section, and a plurality of fixing bolt holes 2b are provided on the upper surface 2a at a predetermined pitch. Further, a substantially V-shaped recess 2c having a pair of track surfaces 4a and 4b on the upper and lower sides is formed on the left and right side surfaces of the guide rail 2, respectively. The track surfaces 4 a and 4 b on the left and right side portions are formed along the longitudinal direction of both side surfaces of the guide rail 2.

The slider 3 includes a slider body 5 having a substantially U-shaped cross section, and a pair of substantially U-shaped end caps 6 attached to both sides of the slider body 5 in the sliding direction. A side seal 15 is attached to the outer end face of each end cap 6. Each side seal 15 has a seal portion 16 that is in sliding contact with the outer surface of the guide rail 2.
2, the slider body 5 has a pair of raceway surfaces 9a and 9b facing the raceway surfaces 4a and 4b of the guide rail 2 on the inner surfaces of both sleeve portions 5b. . A total of four rows of load tracks 10a and 10b are constituted by the track surfaces 9a and 9b of the slider 3 and the track surfaces 4a and 4b of the guide rail 2 which are arranged to face each other. In each load track 10a, 10b, a cylindrical steel roller 8 is interposed as a plurality of rolling elements while being held by a cage 20, and the slider 3 slides on the guide rail 2. Supports the load. A holding piece (not shown) is interposed between the adjacent rollers 8.

  Also, the sleeves 5b of the slider body 5 are provided with through-holes along the sliding direction at a total of four positions on the left and right sides, and cylindrical holders 12 made of a resin material are fitted into the respective through-holes. Yes. The holder 12 has a through hole having a rectangular cross section in which a guide groove 13 for guiding the guide arm portion of the holding piece is formed. The through holes in the holder 12 serve as roller return paths 11a and 11b, and the roller return paths 11a and 11b smoothly guide the movement of the rolling roller 8 (and the holding piece) during infinite circulation. doing. In addition, the joint part of the both ends of the said holder 12 and a pair of end cap 6 is provided with the recessed part and convex part (not shown) which mutually engage, and each roller return path 11a, 11b is made into the predetermined angle. It is positioned.

  Further, the pair of end caps 6 are provided with direction changing paths 14a and 14b, respectively. Each of the direction change paths 14a and 14b is a curved path having a substantially rectangular cross section, and in order to avoid the intersection between the upper and lower load tracks 10a and 10b and the roller return paths 11a and 11b, the direction change paths 14a and 14b are three-dimensionally crossed. At the same time, the load tracks 10a and 10b and the roller return paths 11a and 11b are communicated with each other so that the roller 8 (and the holding piece) is guided to change its circulation direction.

  As a result, the above-described load tracks 10a and 10b, the roller return paths 11a and 11b, and the direction change paths 14a and 14b are arranged in four rows of upper and lower rows for infinite circulation of the plurality of rollers 8 interposed in the load tracks 10a and 10b. The roller circulation path is configured in a substantially elliptical ring shape. Here, these four rows of roller circulation paths in the present embodiment are directed downward as the rotation axis of the rollers 8 circulating in the upper row moves away from the guide rail 2, and the rotation shafts of the rollers 8 circulating in the lower row are guided rails. It is a roller arrangement (hereinafter also referred to as “DB arrangement”) formed so as to go upward as it is away from 2.

  Here, as shown in FIG. 2, the cage 20 includes two arm portions 21 extending in an up and down diagonal direction, a central connector portion 22 that connects the two arm portions 21, and a plurality of rollers 8. It has two flanges (track collar surfaces) 23 formed along both end surfaces. The two flanges (track collar surfaces) 23 are separated into a slider track side and a rail track side by a guide groove for guiding the holding piece.

  Each part of the cage 20 is made of the same material, and one material is selected from metal materials such as brass and bronze or resin materials such as polyacetal resin and polyamide resin. In the example of this embodiment, the cage 20 is manufactured by molding polyacetal resin, which is a resin material, by molding means such as injection molding. In addition, the holder | retainer 20 can be comprised from one component, and may be comprised combining several components.

  On the other hand, the slider body 5 has an inner engagement groove 45 formed between the raceway surfaces 9a and 9b, and two outer engagement grooves 46 are formed on the outer side (upper and lower ends). Has been. And the connector part 22 of the said holder | retainer 20 has the outer convex part 22a engaged with the inner side engagement groove | channel 45, and the two arm parts 21 are each collar part assembled | attached to the upper-lower-end part. 23 is engaged with each outer engagement groove 46. Furthermore, the retainer 20 is fixed so that the movement in the longitudinal direction is restricted by a pair of end caps 6 at both ends of the slider main body 5 and is in close contact with the slider main body 5.

As a result, the retainers 20 are mounted on the left and right load tracks 10a and 10b, respectively, and as shown in FIG. 2, the guide grooves 41a and 41b guide the movement of the guide arm portions of the holding pieces, and the opposite guide surfaces. The side surfaces of the roller 8 that rolls on the load tracks 10a and 10b are held by 40a and 40b to prevent the rollers from dropping off.
As shown in FIGS. 2 and 3, the retainer 20 has two rollers 23 provided on the two arm portions 21, and rollers that circulate the upper and lower rows of the rollers 8 that circulate in the upper row. A first chamfered portion 23m is formed on the lower side of 8 and at both ends in the longitudinal direction (connecting portions with the direction changing paths 14a and 14b). As shown in FIG. 4, the first chamfered portion 23m has a length LM in the longitudinal direction along the slider body 5 longer than a depth LD in a direction facing the end surface of the roller 8 (LM> LD).

  That is, the first chamfer 23m is a chamfer with a gentle inclination. Here, in the example of this embodiment, the first chamfered portion 23m has a length (LM) in the longitudinal direction of 20 mm and a depth (LD) in a direction facing the end surface of the roller 8 of 0.5 mm. Further, the gap in the facing direction between the end face of the roller 8 and the flange 23 is 0.1 mm (when the cage 20 does not lift up). In addition, the part located in the track surface 4a, 4b side of the guide rail 2 among the collar parts 23 is continuing in the longitudinal direction. For this reason, even when the cage 20 is lifted from the slider body 5, there is no concern that the cage 20 protrudes toward the roller 8 to cause a skew, and therefore no chamfering is provided.

Next, the operation and effect of this linear motion guide device will be described.
Similar to the example shown in FIGS. 7 and 8B described above, the cage 20 is deformed such as warpage during manufacturing, twisting of the upper and lower bar-shaped portions of the cage 20, or There may be a case where it floats up from the slider body 5 (for example, symbol F in FIG. 7) due to an assembly error at the time of fixing. When such lifting occurs, the upper track collar surface 23 in the upper row and the lower track collar surface 23 in the lower row move in a direction approaching the end surface of the roller 8 (for example, symbol G in FIG. 7). .

However, according to the cage 20, the track collar surfaces 23 provided on the upper side of the rollers 8 circulating in the upper row and the lower side of the rollers 8 circulating in the lower row are arranged at both ends in the longitudinal direction. Since one chamfer 23m is formed, even when the cage 20 is lifted from the slider body 5, the track collar surface 23 located on the upper side of the upper row and the lower side of the lower row is on the direction change paths 14a and 14b side. It can prevent projecting toward the end surface of the roller 8 rather than the end surface of. Since the first chamfered portion 23m has a length LM in the longitudinal direction longer than the depth LD in the direction facing the end surface of the roller 8, the inclination thereof is gentle, so that the roller slowly rotates. Move in the direction. Therefore, the end face of the roller 8 is not pushed by the projecting collar surface 23 and the skew of the roller 8 can be prevented.
The linear motion guide device according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in the above embodiment, the end of the rolling surface of the slider body 5, that is, the configuration of the ends of the raceway surfaces 9a and 9b is not particularly mentioned. For example, as shown in FIG. When the crowning C is applied to the ends of the rolling surfaces 9a and 9b of the roller 5 in order to reduce the vibration caused by the rollers 8 entering and exiting the load tracks 10a and 10b, the first chamfered portion of the cage 20 is used. The length LM in the longitudinal direction of 23 m is desirably the same as the length LC of the crowning C or longer than the length LC of the crowning C. More preferably, the length LM in the longitudinal direction of the first chamfered portion 23m is 80% or more of the length LC of the crowning C (for example, the length LC of the crowning C is set to 15 mm with respect to the above embodiment). .) With such a configuration, the unstable roller 8 located in the range of the crowning C (length LC) is prevented from being pushed by the two brim portions (track collar surfaces) 23, thereby preventing skew. Is preferred.

  Further, for example, as shown in FIG. 6, a second chamfer 23 n may be further provided on the track collar surface 23 on the lower side of the upper row and the upper side of the lower row arranged in the DB. In this case, the lower side of the upper row and the upper side of the lower row do not protrude toward the end face of the roller 8 even when the cage 20 is lifted. Therefore, the length LN of the second chamfer 23n may be short. This second chamfer 23n has a small lift of the cage 20, and the direction change paths 14a, 14b when the end faces (ridges) on the direction change paths 14a, 14b side are greatly displaced downward in the figure. This is useful for reducing the level difference between the end face on the side and the flange (track collar surface) 23 of the cage 20.

DESCRIPTION OF SYMBOLS 1 Linear motion guide apparatus 2 Guide rail 3 Slider 5 Slider main body 6 End cap 8 Roller (roller)
12 Holder 20 Cage 21 Arm part 22 Connector part 23 Track collar surface (buttock part)
45 Inner engagement groove 46 Outer engagement groove

Claims (1)

Guide rails having a total of four rows of rolling surfaces on the upper and lower sides of the left and right side portions, and a total of four rows of rolling surfaces that form four rows of load tracks opposite to the rolling surfaces of the guide rails And a slider having four rows of roller circulation paths for infinitely circulating a plurality of rollers interposed in the four rows of load tracks, and the four rows of load tracks. A pair of left and right cages assembled to the inner surface of the slider body so as to hold a plurality of rollers, and the four rows of roller circulation paths are configured so that the rotation shafts of the rollers circulating in the upper rows are separated from the guide rails. A linear motion guide device having a roller arrangement formed so that the rotation shaft of the rollers circulating in the lower row is directed downward as it is separated and directed upward as it is separated from the guide rail,
The cage has a track collar surface formed along end faces of a plurality of rollers circulating in each roller circulation path, and circulates the upper and lower rows of rollers circulating in the upper row among the track collar surfaces. The track collar surface provided on the lower side of the roller has first chamfered portions formed at both ends in the longitudinal direction, and the first chamfered portion is in contact with the end surface of the roller circulating in each roller circulation path. The length in the longitudinal direction is longer than the depth in the facing direction ,
The end of the rolling surface of the slider body is crowned,
The length of the said 1st chamfer part in the said longitudinal direction is the same as the length of the said crowning, or is longer than the length of the said crowning, The linear motion guide apparatus characterized by the above-mentioned.

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