JP3898679B2 - Linear motion guide device - Google Patents

Description

  The present invention relates to a linear motion guide device used in a linear guide portion of a machine tool.

  In this type of conventional linear motion guide device, a moving block is movably provided on a track rail via a large number of balls. This moving block includes a block main body provided with a ball rolling groove in a load region provided opposite to the ball rolling groove provided on the track rail, and side covers attached to both ends of the block main body. It becomes the composition. The ball is configured to circulate infinitely through the ball rolling groove in the load area, the direction changing path provided in the side cover and the ball escape path, and a ball retainer is provided at the side edge of the ball rolling groove. .

  However, in the case of the above-described prior art, there is a problem that the weight of the moving block is increased because a metal block cutting product is used as the moving block.

  Further, since the ball escape passage is drilled in the metal block, the number of processing steps is increased, resulting in a high cost.

  Further, when the R piece constituting the inner periphery of the direction changing path is assembled to the end face of the block main body, it is necessary to assemble so that there is no step between the ball rolling groove and the R piece.

  Further, when assembling the ball retainer on the side edge of the ball rolling groove, it is necessary to assemble so that the ball does not interfere with the ball retainer during traveling, and the assembly is troublesome. The large number of such assembly processes is also a factor that increases costs.

  Therefore, conventionally, the ball retainer, the side cover, and the ball escape passage that do not require high rigidity have been reduced in cost as a resin molded product.

  However, each conventional resin molded product is a separate molded product from the block body, and an assembling process is required after molding separately.

  Therefore, it is conceivable to reduce the assembly process by integrally molding the ball retainer and the block body.

  As such an integral molding technique, for example, a linear motion ball bearing as shown in USP 4,128,279 is known.

  As shown in FIG. 14, the linear motion ball bearing includes an outer cylinder 101 having an open cross-sectional shape with a part cut away, and a shaft 105 that is inserted into the outer cylinder 101.

A large number of balls 104 arranged in the axial direction are interposed between the inner periphery of the outer cylinder 101 and the outer periphery of the shaft 105, and the outer cylinder 101 moves linearly along the shaft 105 via the balls 104. ing. The balls 104 are provided in a plurality of rows in the circumferential direction of the outer cylinder 101, and each ball row circulates through a direction changing path 108 at both ends of the outer cylinder 101 and a plurality of no-load ball paths 110 provided on the outer peripheral side of the outer cylinder 101. It is supposed to be. A ball 104 in a load region interposed between the outer cylinder 101 and the shaft 105 is a ball holding portion 106 extending along the axial direction on both sides of the ball row.
Is held by.

  And the said ball | bowl holding | maintenance part 106, the internal peripheral part 108a of the direction change path 108, and the no-load ball path | route 110 were integrally molded with the outer cylinder 101 by insert molding.

  However, in the case of the conventional linear motion ball bearing described above, when insert molding, as shown in FIG. 14C, for example, the outer periphery of the outer cylinder 101 is placed on the first mold 111 and the outer cylinder. The inner periphery of 101 is brought into close contact with the second mold 112 to form the ball holding portion 106 and the cavities 106a and 110a for forming the no-load ball passage 110. Therefore, it is difficult to accurately bring the second molds 111 and 112 into close contact with each other, and there is a problem that a gap is formed between the contact surfaces to generate burrs.

  In particular, if burrs are generated between the contact surfaces of the outer periphery of the outer cylinder 101 and the second mold 112, burrs are generated on the load ball rolling surface, and the burrs need to be removed. However, it is very difficult and practically impossible to remove such burrs generated in the back between the ball holding portions 106 and 106.

  The present invention has been made to solve the above-described problems of the prior art, and the object of the present invention is to provide a moving block that is lightweight, easy to process and assemble, and can smoothly circulate the ball. An object of the present invention is to provide a linear motion guide device.

In order to achieve the above object, in the present invention,
A moving block is movably provided on the track rail via a large number of balls, and the moving block is provided with a ball rolling groove in a load area provided opposite to the ball rolling groove provided on the track rail. A linear motion guide device comprising a main body and side lids attached to both ends of the block main body, wherein the block main body is inserted into the mold with a raceway member formed with a ball rolling groove in the load area. It is integrally formed by insert molding, and a recess is provided on the back surface of the race member opposite to the side on which the ball rolling groove is formed, and the molding material is digged into the recess by integral molding. , the molding material in which bite into the recess, characterized that you load the reverse radial load acting in a direction to lift upwardly the block body from the guide rail.

  The block body is assembled so that the track rail is sandwiched from the left and right via a ball. It is characterized by being.

  The block body is configured to be assembled so as to sandwich the track rail from the left and right via balls, and the track member inserted into the block body is composed of two members respectively disposed on the left and right side portions of the block body, A ball rolling groove is provided on the member.

  The block body has two rows of balls on the left and right, and upper and lower ends of each track member arranged on the left and right are provided with cover parts that surround the balls more than the contact parts of the balls during rolling. The cover portion is shaped to be caught by a part of the mold during insert molding.

  The block main body is a member having a substantially rectangular cross section arranged side by side on the left and right side surfaces of the track rail, and a ball is interposed between the side surface of the block main body and the side surface of the track rail. It is comprised by one member, It is characterized by the above-mentioned.

  The molding material of the block main body excluding the raceway member is one of resin, aluminum die casting, and zinc die casting.

  As described above, the present invention pays attention to the fact that at least the portion where the ball rolling groove is formed needs to have a high surface pressure, and the track member on which the ball rolling groove is formed is a mold. The block body is integrally molded using resin, lightweight aluminum die casting or zinc die casting. Therefore, the conventional metal block can be significantly reduced in weight compared to the moving block.

  Further, if the ball holding portion provided along the ball rolling groove and preventing the drop of the ball is integrally formed with the block main body, a separate ball retainer is not provided and it is not necessary to assemble.

  Further, if the unloaded ball guide portion is integrally formed, it is not necessary to process the ball relief hole as in the prior art, and it is not necessary to assemble it.

  Furthermore, if the direction change path inner periphery guide part that changes the direction of the ball from the load area to the no load area is integrally formed, it is not necessary to separately prepare an R piece as in the conventional case, and it is not necessary to assemble it. Steps between the inner periphery of the direction change path and the loaded ball rolling groove and between the inner periphery of the direction change path and the no-load ball path are eliminated, and the circuit smoothly circulates.

  As described above, according to the present invention, the raceway member in which the ball rolling groove is formed is inserted into the mold, and the block body is integrally formed using resin, lightweight aluminum die casting or zinc die casting. Compared to a moving block using a conventional metal block, the weight can be significantly reduced.

  Also, if at least one of the ball holding part, the no-load ball path, and the ball direction changing path inner peripheral part is integrally formed with the block body, it is not necessary to process it separately, and the number of parts can be reduced and the number of assembly steps can be reduced. The cost can be reduced and the cost can be reduced.

  In particular, if the direction change path inner periphery guide part that changes the direction of the ball from the load area to the no load area is integrally formed, the direction change path inner periphery and the load ball rolling groove, and the direction change path inner periphery Steps between unloaded ball passages are eliminated and circulates smoothly.

  Examples of the present invention will be described below.

  FIG. 1 shows a linear motion guide apparatus according to a first embodiment of the present invention.

That is, the moving block 3 is movably provided on the track rail 1 via a large number of balls 2. The moving block 3 includes a block main body 6 provided with a ball rolling groove 5 in a load region provided opposite to the ball rolling groove 4 provided on the track rail 1, and sides attached to both ends of the block main body 6. And a lid 7.

  The block body 6 is obtained by integrally molding the resin portion 9 by insert molding in which a raceway member 8 in which the ball rolling grooves 5 are formed is inserted into a mold. Instead of resin, a lightweight aluminum die casting or zinc die casting may be used. The raceway member 8 needs to have high surface pressure resistance, and preferably has good hardenability as a material and high hardness (for example, about HRC 58 to 64), and high wear resistance and fatigue resistance.

  The block body 6 has a U-shaped cross-section assembled so as to sandwich the track rail 1. Balls 2 are interposed between the left and right inner side surfaces of the block body 6 and the left and right side surfaces of the track rail 1. Each of the raceway members 8 and 8 is formed with ball rolling grooves 5 and 5, respectively. Each of the left and right ball rolling grooves 5 and 5 is provided in two upper and lower portions.

The ball rolling grooves 4 and 4 on the side of the track rail 1 are also provided on the left and right, respectively, in two rows, and in this embodiment, the lines connecting the contact portions between the pair of opposing ball rolling grooves 4 and 5 and the ball are in contact with each other. As a square line, the left and right contact angle line L1 is configured to be outwardly opened so as to narrow toward the center of the track rail 1.

  At the upper and lower end portions of the track members 8, 8 arranged on the left and right, the cover portions 81, 81 surrounding the ball 2 more than the contact portions of the ball 2 at the time of rolling are provided. Has a shape that is caught by a part of the mold during insert molding.

  Further, a recess 82 is provided on the back surface of the track members 8, 8, and a part of the resin portion 9 is bitten into the recess 82, so that the block body 6 acts in the direction of lifting upward from the track rail 1. A radial load is applied.

  Further, along the upper and lower ball rolling grooves 5 and 5, first and second ball holding portions 91a and 91b for preventing the ball 2 from dropping off are integrally formed.

  On the other hand, on both end surfaces of the block main body 6, inner peripheral guide portions 92 of a direction change path for changing the direction of the ball 2 from the no-load region to the load region are formed. A pipe-shaped direction change path C that bends in a U-shape is formed together with the outer periphery guide part 71 of the direction change path provided on the side lid 7 with the inner peripheral guide portion 92.

  Furthermore, an unloaded ball passage 93 extending in parallel with the ball rolling grooves 5 and 5 is formed in the resin portion 9. The unloaded ball passage 93 is a through hole having a circular cross section, and is integrally formed at the time of insert molding.

  Here, the ball holding portions 91a and 91b, the inner circumferential guide portion 92, and the unloaded ball passage 93 do not necessarily have to be integrally formed at the time of insert molding, and any one of them may be integrally formed. . In some cases, only the track member may be integrally formed during insert molding.

  In the linear motion guide device having the above-described configuration, the raceway member 8 in which the ball rolling groove 5 is formed is inserted into the mold, and therefore, compared with a moving block obtained by cutting a conventional metal block. The weight can be greatly reduced.

  Further, if the ball holding portions 91a and 91b are also integrally formed along the ball rolling groove 5, it is not necessary to provide a separate ball retainer and to assemble it.

  Further, if the unloaded ball passage 93 is integrally formed, it is not necessary to process the ball relief hole as in the conventional case, and it is not necessary to assemble it.

  Furthermore, since the direction change path inner periphery guide portion 92 that changes the direction of the ball from the load area to the no load area is also integrally formed, there is no need to separately prepare an R piece as in the conventional case, and no need to assemble. In addition, there is no step between the direction change path inner periphery 92 and the loaded ball rolling groove 5 and between the direction change path inner periphery 92 and the unloaded ball passage 93, and the ball 2 circulates smoothly.

  When the moving block 3 is formed, as shown in FIG. 3, the ball rolling grooves 5 and 5 of the two race members 8 and 8 face each other and are inserted into the mold 10. The ball rolling grooves 5 and 5 of the race members 8 and 8 are supported by the ball rolling groove support portion 10a of the mold, and the ball rolling grooves 5 and 5 of the race members 8 and 8 are formed using a molding pressure. The mold 10 is pressed and molded.

  More specifically, the ball rolling groove support portion 10a of the mold 10 is formed in the movable mold 10A, and the track members 8, 8 are arranged on the left and right sides thereof. At this time, the cover 81 of the track member 8 is caught by the ball rolling groove support 10a.

  Next, in the mold 10, the movable mold 10A moves to the fixed mold 10B side and is clamped.

  Thereafter, the pressing member 11 disposed on the back surface of the track member 8 in the mold 10 presses the track member 8, so that the ball rolling groove support portion 10 a of the mold 10 becomes the ball rolling groove 5 of the track member 8. Will come into strong contact.

  The ball rolling groove support portion 10a of the mold 10 has two left and right portions, but the parallelism thereof is accurately formed and finished so as to have the same shape as the ball rolling groove 5 of the track member 8.

  When the resin molding is performed in such a state, the track member 8 is further pressed against the ball rolling groove support portion 1a of the central mold by the molding pressure of the resin.

  After molding, when the mold is opened and the molded product is taken out, the block main body 6 into which the two track members 8 are inserted is completed. Direction change path inner periphery guide portions 92 are formed at both ends of the block body 6, and no-load ball passages 93 are formed in both sides of the block body 6. Ball holding portions 91 a and 91 b are formed on both side edges of the ball rolling groove of the track member 8 inserted into the block body 6. These parts are formed in such a manner that the other parts are continuous with the ball rolling groove of the raceway member 8 as a reference position, and the parts at both ends are formed simultaneously.

  Because of such a molding method, the parallelism of all ball rolling grooves, the distance between the grooves, and the position from the upper surface or side end of the moving block 6 can maintain the same size and accuracy in all molding shots. it can. That is, when two track blocks are combined with one track rail 1 and track rails are combined in two rows in parallel, this characteristic improves the accuracy of the entire table apparatus.

  Further, as described above, the ball rolling groove burr due to molding is pressed against the pressing member 11 and the resin rolling pressure makes the ball rolling groove come into strong contact with the contact portion of the mold, so there is no gap between them. , No burr occurs.

Next, FIG. 5 shows another aspect of the first embodiment , and FIGS. 4 and 6 to 8 show first to fourth reference examples .

  That is, in each case, the track member 8 is composed of two members, one on each of the left and right sides of the block body 6.

  FIG. 4 shows a structure in which the track member 8 is formed of a thin member formed into a C-shaped cross section. In this case, a third ball holding portion 91c is provided between the upper and lower ball rows. Other configurations are exactly the same as those in FIG.

FIG. 5 shows an inwardly open contact structure in which the contact angle line L2 between each opposing pair of ball rolling grooves 4 and 5 and the ball 2 opens toward the center of the track rail 1. Similar to the example, a third ball holding portion 91c is provided between the upper and lower ball rows. Other configurations are exactly the same as those in FIG.

  FIG. 6 also shows a configuration in which the track member 8 is formed of a thin member formed with a C-shaped cross section, and there are two rows of balls on the left and right, but the upper end corner of the track rail is sandwiched between the upper surface side and the side surface side. Are arranged as follows.

  In this case, since the unloaded ball passages 93 and 93 corresponding to the respective ball rows arranged in the vertical direction are separated from each other, as shown in FIG. Yes.

  FIG. 7 shows a type having a single row of balls on the left and right, and the track member 8 is constituted by a thin member formed in a C-shaped cross section.

  In FIG. 8, the block body 6 has a substantially L-shaped cross section, the left and right ball rows are interposed between the side surface of the track rail 1 and the inner side surface of the block body 6, and the other ball row is the top surface of the track rail 1. It is interposed between the corner portion and the corner portion of the inner side surface of the block main body.

  The track member 8 is constituted by a thin member having a C-shaped cross section.

  FIG. 9 (a) shows a second embodiment of the present invention.

  This second embodiment also has a moving block 3 that slides along the track rail 1 via balls 2 arranged on the left and right sides so as to straddle the track rail 1 from side to side. 208 is also different from the first embodiment in that it is constituted by one member arranged so as to straddle the track rail 1 from side to side. Since other configurations and operations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.

  In the case of this second embodiment, as shown in FIG. 9 (b), the ball rolling groove 205 of the track member 208 and the ball rolling groove support portion 10a of the mold 10 do not enter the molding material. It is made to contact in the state of contact.

  In order to prevent burrs, it is not necessary for the ball rolling groove 5 and the ball rolling groove support portion 10a of the mold 10 to be completely in close contact with each other. It is sufficient that the size is as large as possible.

10 to 12 show fifth to seventh reference examples .

  FIG. 10 shows a structure in which the track member 208 is formed of a thin-walled member having a C-shaped cross section, and the other configuration is exactly the same as the configuration shown in FIG.

  FIG. 11 also shows a structure in which the track member 8 is formed of a thin member formed into a C-shaped cross section, and there are two rows of balls on the left and right sides, but the upper end corners of the track rail 1 are on the upper surface side and the side surface side. It is arranged so as to sandwich it.

  FIG. 12 is a type having a single row of balls on the left and right, and the track member 8 is constituted by a thin member molded into a C-shaped cross section.

FIG. 13 shows an eighth reference example.

  In other words, the moving block 303 is movably provided on the track rail 301 via a large number of balls 302. The moving block 303 includes a block main body 306 provided with a ball rolling groove 305 in a load region provided opposite to the ball rolling groove 304 provided on the track rail 301, and sides attached to both ends of the block main body 306. And a lid 307.

  The block body 306 is obtained by integrally molding the resin portion 309 by insert molding in which the raceway member 8 in which the ball rolling groove 305 is formed is inserted into a mold.

  The block main body 306 is a member having a rectangular cross section arranged in parallel with the track rail 301, and a ball 302 is interposed between the opposing side surfaces of the block main body 306 and the track rail 301.

  The track member 308 is a thin member having a C-shaped cross section, and is formed with two upper and lower ball rolling grooves 305 and 305.

  Further, along the upper and lower ball rolling grooves 305 and 305, first and second ball holding portions 91a and 91b and a third ball holding portion 91c for preventing the ball 302 from dropping off are integrally formed.

  In addition, although not shown in the figure, the inner periphery guide part of the direction change path similar to that shown in FIG.

  Further, an unloaded ball passage 393 extending in parallel with the ball rolling grooves 305 and 305 is formed in the resin portion 309, and is integrally formed at the time of insert molding.

  Since the molding procedure in this case is the same as that in FIG. 1, the description thereof is omitted.

  Further, the number of ball rows may be one as shown in FIG.

FIG. 1 is a view showing a linear motion guide apparatus according to a first embodiment of the present invention. FIG. 2 is a view showing a linear motion guide apparatus according to the first embodiment of the present invention. FIG. 3 is an explanatory view of an insert molding process of the block main body of the linear motion guide device of the first embodiment. FIG. 4 is a diagram showing a first reference example of the present invention. FIG. 5 is a diagram showing an aspect of the first embodiment of the present invention. FIG. 6 is a diagram showing a second reference example of the present invention. FIG. 7 is a diagram showing a third reference example of the present invention. FIG. 8 is a diagram showing a fourth reference example of the present invention. FIG. 9 is a view showing a linear motion guide apparatus according to the second embodiment of the present invention. FIG. 10 is a diagram showing a fifth reference example of the present invention. FIG. 11 is a diagram showing a sixth reference example of the present invention. FIG. 12 is a diagram showing a seventh reference example of the present invention. FIG. 13 is a view showing a linear motion guide apparatus according to an eighth reference example of the present invention. FIG. 14 is a view showing a conventional linear motion bearing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Track rail 2 Ball 3 Moving block 4, 5 Ball rolling groove 6 Block main body 7 Side cover 8 Track member 9 Resin part 91a-91c 1st-3rd ball holding part 92 Direction change path inner periphery guide part 93 Unloaded ball Passage 10 Mold 10a Ball rolling groove support part

Claims (7)

A moving block is movably provided on the track rail via a large number of balls, and the moving block is provided with a ball rolling groove in a load area provided opposite to the ball rolling groove provided on the track rail. In a linear motion guide device comprising a main body and side lids attached to both ends of the block main body,
The block body is integrally formed by insert molding in which a raceway member in which a ball rolling groove in the load area is formed is inserted into a mold and molded,
A recess is provided on the back surface of the raceway member opposite to the side on which the ball rolling groove is formed, and the molding material is bitten into the recess by integral molding ,
Linear motion guide device molding material was bite into the recess, characterized that you load the reverse radial load acting in a direction to lift upwardly the block body from the guide rail. Of the ball holding portion provided along the ball rolling groove to prevent the ball from falling off, the direction change path inner periphery guide portion for changing the direction of the ball from the no-load region to the load region, and the no-load ball guide portion, The linear motion guide device according to claim 1 , wherein at least one is integrally formed at the time of insert molding of the block main body . The block body is assembled so that the track rail is sandwiched from the left and right via a ball. The track member inserted into the block body is composed of a single member, and ball rolling grooves are provided on both the left and right sides of the track member. It is optionally linear motion guide apparatus according to claim 1, characterized in Rukoto. The block body is configured to be assembled so as to sandwich the track rail from the left and right via balls, and the track member inserted into the block body is composed of two members respectively disposed on the left and right side portions of the block body, linear motion guide apparatus according to claim 1, characterized in Rukoto ball rolling groove is provided in the member. The block body has two rows of balls on the left and right, and upper and lower ends of each track member arranged on the left and right are provided with cover parts that surround the balls more than the contact parts of the balls during rolling. The linear motion guide device according to claim 4 , wherein the cover portion is configured to be hooked to a part of a mold during insert molding . The block main body is a member having a substantially rectangular cross section arranged side by side on the left and right side surfaces of the track rail, a ball is interposed between the side surface of the block main body and the side surface of the track rail, and the track member inserted into the block main body is The linear motion guide device according to claim 1, wherein the linear motion guide device is constituted by a single member. The linear motion guide device according to claim 1 , wherein the molding material of the block body excluding the raceway member is one of resin, aluminum die casting, and zinc die casting .

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