JP3898240B2 - Linear motion guide device and moving block forming method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a linear motion guide device used in a linear guide part of various industrial machines such as machine tools, and more particularly to a technique for reducing weight and facilitating molding. Further, the present invention relates to a moving block and a track rail of the linear motion guide device and a manufacturing method thereof.
[0002]
[Prior art]
As a conventional linear motion guide device of this type, for example, there is a device as shown in FIG. 6 (see Japanese Patent Publication No. 5-36648). That is, the track rail 100, the moving block 101 provided movably along the track rail 100, and the load rolling element rolling grooves 101 a and 100 a provided between the opposed surfaces of the moving block 101 and the track rail 100 are interposed. And a number of balls 102 to be worn. In this conventional example, the outer periphery of the moving block 101 is constituted by the frame 103 to reduce the weight.
[0003]
[Problems to be solved by the invention]
However, in the case of the above-described prior art, although the moving block 101 is reduced in weight, since the outer peripheral frame 103 has an open cross-sectional shape partially opened by the slit 103a, the rigidity is low and heavy load is supported. In such a case, there is a problem that the accuracy of feeding a supporting object such as a table is deteriorated.
[0004]
Further, in the case of the prior art, only the frame structure is disclosed, and the configuration of the circulation path of the ball 102 supported by the moving block 101 is not described. The major issue was how to construct and mold.
[0005]
As a configuration of the ball circulation path of such a linear motion guide device, for example, an integral molding method as shown in FIG. 7 is known (see US Pat. No. 4,128,279).
[0006]
In other words, the outer cylinder 120 is partially cut away, and the shaft 121 is inserted into the outer cylinder 120. A large number of balls 122 arranged in the axial direction are interposed between the inner periphery of the outer cylinder 120 and the shaft 121, and the outer cylinder 120 moves linearly along the shaft 121 via the balls 122. Yes. The balls 122 are provided in a plurality of rows in the circumferential direction of the outer cylinder 120, and each ball row passes through a direction changing path 123 at both ends of the outer cylinder 120 and a plurality of no-load ball escape passages 124 provided on the outer peripheral side of the outer cylinder 120. It comes to circulate. The load region balls 122 interposed between the outer cylinder 120 and the shaft 121 are held by ball holding portions 125 extending along the axial direction at both ends of the ball row.
[0007]
And the said ball holding | maintenance part 125, the inner peripheral part 123a of the direction change path 123, and the no-load ball escape passage 124 were integrally molded with the outer cylinder 120 by insert molding.
[0008]
However, in the above-described conventional integral molding method, when insert molding is performed, as shown in FIG. 7C, for example, the outer periphery of the outer cylinder 120 is used as the first mold 126 and the inner periphery of the outer cylinder 120 is used as the inner mold. The ball holding portion 125 and the cavities 125a and 124a for forming the no-load ball escape passage 124 are formed in close contact with the second mold 127. The inner and outer circumferences of the outer cylinder 120 are first and second. There is a problem that it is difficult to make the metal molds 126 and 127 closely contact with each other, and there is a gap between the contact surfaces to generate burrs.
[0009]
In particular, when molding resin flows between the contact surfaces of the outer periphery of the outer cylinder 120 and the second mold 127, 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 125 and 125.
[0010]
The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to provide a linear motion guide device that can be reduced in weight while maintaining high rigidity and can be easily molded. It is to provide a method for forming a moving block.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, in the linear motion guide apparatus of the present invention, the linear rail is provided between the track rail, the movable block provided movably along the track rail, and the opposed surface of the movable block and the track rail. A large number of balls interposed between the loaded rolling element rolling grooves, an unloaded rolling element escape passage provided in the moving block in parallel with the loaded rolling element rolling groove, and provided at both ends of the moving block, A side cover provided with a direction changing path for infinite circulation of the rolling elements by changing the direction of the rolling elements in the load region interposed between the rolling elements of the loaded rolling elements to an unloaded rolling element escape passage; And a rolling element holding member that prevents the rolling elements positioned in the rolling rolling element rolling grooves from falling off the moving block when the moving block is disposed on the outer periphery of the moving block. Closed A hollow structural member surface structure, characterized by being composed of a filling member, which is filled into the hollow interior of the hollow structural member.
[0012]
The hollow structural member is made of a hard material such as steel having pressure resistance, and the filling member is made of thermoplastic resin, die cast, granite, aluminum (Al) light metal, or the like. Here, the meaning of the term granite itself is granite, but here it is used as the meaning of a structural material in which an epoxy resin and crushed stone such as granite are mixed and cast into a mold.
[0013]
The filling member of the moving block is provided with a no-load rolling element escape passage.
[0014]
At least one of the inner periphery of the direction change path and the rolling element holding member is integrally formed with the hollow structural member.
[0015]
The moving block is formed by drawing the pipe material with the cross-sectional shape of the moving block, cutting the pultruded product into a predetermined length to form a hollow structure, and then filling the hollow structure with a filling member. It is characterized by doing.
[0016]
The filling member is filled by placing the hollow structural member in the mold with reference to the loaded rolling element rolling groove and pouring the fluidized molding material.
[0017]
Another method of forming the moving block is to draw a pipe material from a material softer than the pipe material as a core metal, shape the pipe material into a predetermined cross-sectional shape, and form the soft metal core metal into a cross-sectional shape of the pipe material. The moving block is formed by plastic deformation following the above and cutting the pultruded product with a predetermined dimension.
[0018]
[Action]
In the present invention, since the hollow structural member has a closed cross-sectional configuration surrounding the entire circumference of the moving block, it has higher rigidity, higher rigidity and lighter weight than the moving block of the conventional open cross-section frame structure. Can be achieved.
[0019]
Further, the hollow structural member is reinforced by the filling member, and the rigidity is further increased.
[0020]
If the no-load rolling element escape passage is provided in the filling member, the molding can be easily performed as compared with the conventional case where the no-load rolling element escape passage is provided in the hard block.
[0021]
If the inner periphery of the direction change path and the rolling element holding member are also integrally formed with the hollow structural member, the assembly process can be reduced. In particular, if the filling member, the inner periphery of the direction change path, or the rolling element holding member are integrally formed by molding, the processing process is simplified.
[0022]
If the hollow structural member is formed into a predetermined cross-sectional shape by pulling out the pipe material, the yield is good and the forming can be performed very efficiently.
[0023]
When the filling member is molded by molding, if the hollow structure member is positioned in the mold with reference to the loaded rolling element rolling groove, burrs are generated between the loaded rolling element rolling groove and the mold. Can be prevented.
[0024]
Here, in order to prevent burrs, the contact surface between the outer cylinder and the mold does not need to be completely in close contact with each other, and it is large enough to prevent intrusion of the molding material even if there is a gap. I just need it.
[0025]
Furthermore, if a soft material is used as the core when the pipe material is drawn, the filling member can be filled simultaneously with the drawing, and the number of processes can be further reduced.
[0026]
【Example】
Hereinafter, the present invention will be described based on illustrated embodiments.
[0027]
1 and 2 show a linear motion guide apparatus according to a first embodiment of the present invention.
[0028]
This linear motion guide device 1 has a configuration in which a moving block 2 is supported so as to be movable along a track rail 4 via balls 3 as a large number of rolling elements. The rolling elements include various types of rollers such as a cylindrical shape and a conical shape.
[0029]
The moving block 2 has a U-shaped cross section and includes a pair of leg portions 5 and 5 that sandwich the track rail 4 and a horizontal portion 6 that rigidly connects the leg portions 5 and 5.
[0030]
The moving block 2 is provided with four ball circulation paths 7 for circulating and guiding a large number of balls 3. In this example, two upper and lower ball circulation paths 7 are formed on the left and right leg portions 5 and 5.
[0031]
Each ball circulation path 7 includes a load ball path 8 of load ball rolling grooves 8 a and 8 b as load rolling element rolling grooves formed on the opposed surfaces of the moving block 2 and the track rail 4, and one end of the load ball path 8. The unloaded ball escape passage 10 as an unloaded rolling element escape passage in the no-load region for returning the ball 3 from the other end to the other end side, and the moving block 2 between the load ball passage 8 and the end of the unloaded ball escape passage 10. It is comprised from the direction change path 11 connected in the both ends position.
[0032]
The direction change path 11 is a U-shaped passage, and an inner peripheral portion 11 a thereof is integrally joined to an end face of the moving block 2, and an outer peripheral portion is constituted by a side lid 14 that is separate from the moving block 2.
[0033]
A contact angle line L1 indicating the direction of the contact angle of the four load balls 3 is inclined toward the center of the track rail 4 in a closing direction with respect to the horizontal line H. Here, the contact angle line L1 means a line connecting the contact points of the ball balls 8a and 8b on the moving block 2 side and the track rail 1 side of the load balls 3 in each row, and so on.
[0034]
In this embodiment, a filling member 15 in which an unloaded ball escape passage 10 of the ball circulation path 7 is formed, a direction change path inner peripheral portion 11a, and a retainer portion 17 as a rolling element holding member extending along the load ball passage 8 are provided. The moving block 2 is integrally formed.
[0035]
The direction change path inner peripheral portion 11a is connected to the no-load ball escape passage 10 as shown in FIG.
[0036]
Since the unloaded ball escape passage 10 and the ball direction changing path 11 are integrally formed, a continuous guide surface is formed at the connecting portion between the loaded ball escape path 10 and the ball direction changing path 11 so that the ball 3 can be made smooth. Safe circulation is guaranteed.
[0037]
On the other hand, the retainer unit 17 holds the ball 3 so that the ball 3 does not fall off the moving block 2 when the track rail 4 is pulled out of the moving block 2, and in the state where the track rail 4 and the moving block 2 are assembled, The dimensions are set so that a gap is formed between the retainer portion 17 and the ball 3 so as not to hinder the movement of the ball 3 rolling on the ball passage 8.
[0038]
In this embodiment, a first retainer 30 is disposed between the upper and lower load balls 3 of the left and right legs 5 and 5 and holds the lower edge of the upper ball 3 and the upper edge of the lower ball 3; The second retainer 31 holds the upper edge of the upper ball 3, and the third retainer 32 holds the lower edge of the lower ball 3. An upper ball row is held by the first retainer 30 and the second retainer 31, and a lower ball row is held by the first retainer 30 and the third retainer 32. Then, the ball 3 is exposed from between the first to third retainers 30, 31, 32 and comes into contact with the loaded ball rolling groove 8 b on the track rail 4 side so as to roll freely.
[0039]
Both end portions of the first to third retainers 30, 31, 32 are integrally connected to the direction change path inner peripheral portion 11a.
[0040]
As shown in FIG. 1A, the moving block 2 includes a hollow structural member 200 having a closed cross-sectional structure that forms the entire outer periphery of the moving block 2, and a filling member 15 that fills the hollow interior of the hollow structural member 200. And is composed of.
[0041]
The hollow structural member 200 is made of a hard material such as steel, and the first frame 201 constituting the upper surface of the horizontal portion 6 of the moving block 2, the second frame 202 constituting the lower surface of the horizontal portion 6, and the first frame 201. The left and right third frames 203, 203 extending downward from the left and right side edges of the frame 5 and constituting the outer surface of the leg 5 and the lower ends of the second frame 202 extending downward from the left and right side edges of the third frame 203, 203 And left and right fourth frames 204 and 204 constituting the inner surface of the leg portion 5, and fifth frames 205 and 205 constituting the lower surface of the leg portion 5. The first to fifth frames 201 to 205 are spaced apart from each other and do not contact each other, and a space having a U-shaped cross section is formed inside.
[0042]
On the other hand, the filling member 15 is made of thermoplastic resin, die casting, granite, aluminum (Al) light metal, or the like, and is between the first and second frames 201 and 202 and between the third and fourth frames 203 and 204. The space is closely packed. The filling member 15 can be molded easily by thermoplastic resin molding, die casting, or granite casting, or by drawing a pipe using an Al-based light metal as a core metal.
[0043]
As described above, granite is a structural material that is formed by mixing an epoxy resin and crushed stone such as granite and pouring them into a mold, and has an advantage of low damping and thermal deformation. Since the unloaded ball circulates in the moving block 2, the circulating sound of the ball becomes a problem. If granite is used, silence can be improved.
[0044]
In this embodiment, the same resin material as the retainer portion 17 and the ball direction changing path inner peripheral portion 11a is used as the material of the filling member 15, and the filling member 15, the retainer portion 17 and the ball direction changing path inner peripheral portion 11a are hollow. It is integrally formed with the structural member 200.
[0045]
Next, a method for forming the moving block will be described with reference to FIGS. 3 and 4.
[0046]
First, as shown in FIG. 3, the hollow structural member 200 is formed by drawing a pipe or pipe forging.
[0047]
That is, as shown in FIG. 3A, the pipe material 210 is pulled out through a die 211 having a predetermined shape. The cross-sectional shape of the pipe material 210 is a closed cross-sectional shape such as a circle as shown in FIG. The drawn product 212 is formed as a long body having a cross-sectional shape of the hollow structural member 200 as shown in FIG. 4C, and the product 212 is formed into a predetermined length as shown in FIG. The hollow structure member 200 having a predetermined size is cut out by cutting.
[0048]
In this way, the complicated shape of the moving block 2 can be formed very easily by drawing, and a significant cost reduction can be achieved. Of course, it can be formed by press forming in addition to drawing and forging.
[0049]
Next, as shown in FIG. 4, the hollow structure member 200 is filled with the filling member 15 by molding.
[0050]
FIG. 4 is a schematic configuration diagram of a mold, in which a cavity 41 for forming a filling member is formed in the hollow interior of the hollow structural member 200, and a cavity 42 for forming the retainer 17 on the inner peripheral portion of the leg portion. The cavity 43 for shape | molding the direction change path inner peripheral part 11a is each provided in the front-back both ends of the part. The fixed die 44 is provided with a ridge 45 for fitting and positioning the load ball rolling groove 8a, and the movable die 46 is provided with a pin 47 for forming the no-load ball escape passage 10. ing.
[0051]
During insert molding, as shown in FIG. 4 (c), the positioning in the mold 40 with respect to the loaded ball rolling groove 8a of the moving block 2. Thus, if insert molding is performed with reference to the loaded ball rolling groove 8a, the position of the unloaded ball escape passage 10 and the position of the retainer portion 17 are determined with reference to the loaded ball rolling groove 8a. The relative positional relationship among the loaded ball rolling path 8, the direction changing path 11, and the unloaded ball escape path 10 constituting the path 7 can be set accurately.
[0052]
Further, since the positioning of the hollow structural member 200 in the mold 40 is performed based on the load ball rolling groove 8a, the contact portion with the hollow structural member 200 is only the load ball rolling groove 8a. Well, other parts of the mold 40 may be in a non-contact state, so that precise processing is not necessary, and the manufacture becomes very easy.
[0053]
Thereby, the filling of the filling member 15, the formation of the unloaded ball escape passage 10 into the filling member 15, and the shaping of the retainer 17 and the ball direction change path inner peripheral portion 11 a can be performed simultaneously.
[0054]
Thereafter, the ball 3 is accommodated in the ball circulation path 7 of the moving block 2 and the side lid 14 is attached.
[0055]
In the present invention, since the filling member 15 is integrally formed with the moving block 2 by insert molding, the drilling of the no-load ball escape passage 10 is not required, and the manufacture becomes very simple. As insert molding, in addition to resin molding, you may comprise by die-cast molding, a sintered metal, etc.
[0056]
Further, as another method of forming the moving block, as shown in FIG. 4, when filling the pipe material 210 of FIG. 3 without drawing the filling member 15 by mold forming, a material softer than the pipe material 210 is used. As a core metal, the pipe material 210 is molded into a predetermined cross-sectional shape, and the soft metal core metal is plastically deformed in accordance with the cross-sectional shape of the pipe material. Filling can be performed simultaneously with the drawing process.
[0057]
Thus, when drawing and filling is performed using a cored bar, it is necessary to separately form the unloaded ball escape passage.
[0058]
FIG. 5 (a) shows the left and right fourth frames 204, 204 constituting the inner surface of the leg 5 of the moving block 2 with two upper and lower arc-shaped cross sections corresponding to the upper and lower two ball rolling grooves 8a. 204a is provided, and a ball rolling groove 8a is formed on the inner periphery of the arcuate cross section 204a.
[0059]
1 except that the structure of the fourth frame 204 and the left and right second retainers 31 of FIG. 1 are integrated via a resin portion 31a joined to the lower surface of the second frame 202. Therefore, the same components are denoted by the same reference numerals and description thereof is omitted.
[0060]
FIG. 5B shows a structure in which the contact angle line L2 indicating the direction of the contact angle of the four load balls 3 is inclined in the direction to open with respect to the horizontal line H toward the center of the track rail 4. . Such a contact structure can be achieved by providing the left and right fourth frames 204a constituting the inner surface of the leg 5 of the moving block 2 with the arc-shaped cross-section 204a where the ball rolling groove 8a is to be formed.
[0061]
In this case, a jetty 204b that protrudes toward the track rail 4 is provided between the upper and lower arc-shaped cross-sections 204a and 204a, and ball rolling grooves 8a are provided on both the upper and lower inclined surfaces of the jetty 204b. . Further, this jetty 204b tip, because of the resin retainer 33 that to prevent dropping of the ball 3 is disposed in removing the movable block 6 from the track rail 4.
[0062]
On the other hand, a concave groove 4a is formed on both the left and right side surfaces of the track rail 4 corresponding to the jetty 33 on the moving block 6 side, and the ball rolling on the moving block 6 side is formed at the upper and lower even corners of the concave groove 4a. A ball rolling groove 8b opposite to the groove 8a is provided, and the ball 3 is interposed between the moving block 6 and the ball rolling grooves 8a and 8b of the track rail 4 so as to roll freely.
[0063]
Other configurations and operations are the same as the configuration of FIG. 1, and the same components are denoted by the same reference numerals and description thereof is omitted.
[0064]
In the above-described embodiment, the linear motion guide device having the linear track rail has been described. However, it is needless to say that the linear motion guide device can be slidably assembled to the curved track rail.
[0065]
【The invention's effect】
As described above, according to the present invention, the hollow structural member has a closed cross-sectional configuration that surrounds the entire circumference of the moving block. It is rigid and can be reduced in weight.
[0066]
Further, the hollow structural member is reinforced by the filling member, and the rigidity is further increased.
[0067]
If the no-load rolling element escape passage is provided in the filling member, the molding can be easily performed as compared with the conventional case where the no-load rolling element escape passage is provided in the hard block.
[0068]
If the inner periphery of the direction change path and the rolling element holding member are also integrally formed with the hollow structural member, the assembly process can be reduced. In particular, if the filling member, the inner periphery of the direction change path, or the rolling element holding member are integrally formed by molding, the processing process is simplified.
[0069]
If the hollow structural member is formed into a predetermined cross-sectional shape by pulling out the pipe material, the yield is good and the forming can be performed very efficiently.
[0070]
When the filling member is molded by molding, if the hollow structure member is positioned in the mold with reference to the loaded rolling element rolling groove, burrs are generated between the loaded rolling element rolling groove and the mold. Can be prevented.
[Brief description of the drawings]
FIG. 1 shows a linear motion guide apparatus according to an embodiment of the present invention. FIG. 1 (a) is a longitudinal sectional view, and FIGS. 1 (b) and 1 (c) show the configuration of a ball circulation path. FIG.
2 is an external perspective view of the linear motion guide device of FIG. 1. FIG.
FIG. 3 is a diagram illustrating an example of a method for manufacturing a moving block.
FIG. 4 is a diagram showing an insert molding process of a moving block of the linear motion guide device of the present invention.
FIGS. 5 (a) and 5 (b) are views showing a linear motion guide apparatus according to another embodiment of the present invention.
FIG. 6 is a cross-sectional view of a conventional linear motion guide device.
FIG. 7 is a diagram showing an insert molding method of a conventional linear motion guide device.
[Explanation of symbols]
1 Linear motion guide device 2 Moving block 3 Ball (rolling element)
4 Track rail 7 Ball circulation path 8 Loaded ball path 10 Unloaded ball escape path 11 Direction change path 11a Direction change path inner peripheral part 14 Side cover 15 Filling member 17 Retainer part 200 Hollow structure members 201 to 205 First to fifth frames

Claims (3)

A track block, a moving block provided movably along the track rail, a number of balls interposed between rolling rolling element rolling grooves provided between opposing surfaces of the moving block and the track rail, A no-load rolling element escape passage provided in the moving block in parallel with the loaded rolling element rolling groove, and a rolling element in a load region provided at both ends of the moving block and interposed between the loaded rolling element rolling grooves. A side cover provided with a direction changing path that changes direction to an unloaded rolling element escape passage and infinitely circulates the rolling element, and a rolling element that is positioned in the rolling element rolling groove when the track rail is removed from the moving block. In a linear motion guide device comprising a rolling element holding member that prevents falling off,
The moving block is composed of a hollow structural member having a closed cross-sectional structure that constitutes the entire outer periphery of the moving block, and a filling member that fills the hollow interior of the hollow structural member, and
Linear, characterized in that said at least the rolling element retaining member of the direction changing passage inner periphery portion and the rolling member holding member is molded integrally with the hollow structural member by molding using the filling member of the same material Exercise guidance device. To draw a pipe material with a cross-sectional shape of a moving block, cut a pultruded product into a predetermined length to form a hollow structural member , and then form a no-load rolling element escape passage in the hollow of the hollow structural member In a molding method of a moving block of a linear motion guide device in which a hollow member of a hollow structure member is filled in the hollow structure member in a state where the hollow structure member is disposed in a mold having a pin of
Filling of the filling member is performed by placing the hollow structural member in the mold with reference to the loaded rolling element rolling groove and pouring the fluidized molding material into the moving block of the linear motion guide device. Molding method. A moving block of a linear motion guide device that draws a pipe material with a cross-sectional shape of a moving block, cuts a drawn product into a predetermined length to form a hollow structural member, and then fills the hollow structural member with a filling member. In the molding method of
Filling of the filling member is performed by placing a hollow structural member in the mold with reference to the loaded rolling element rolling groove and pouring the fluidized molding material into the moving block of the linear motion guide device. Molding method.

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