JPH08326747A - Rectilinear motion guide, and method of forming shifting block - Google Patents

Abstract

PURPOSE: To materialize weight reduction and facilitate the formation while keeping high rigidity by constituting a shifting block of a hollow structural member of closed section structure, which constitutes the whole area of the periphery, and a filling member inside its hollow. CONSTITUTION: A shifting block 2 is constituted of a hollow structural member 200 of closed section structure, which constitutes the whole circumference of its periphery, and a filling member 15 inside its hollow. For the hollow structural material 200, hard material such as steel or the like is used, and the first - the fifth frames 201-205 are separate and not in contact with each other, and space U-shaped in cross section is made inside, and for the filling member 15, thermoplastic resin, light metal, or the like is used. The hollow structural member 200 is molded by the drawing of a pipe and pipe forging, and the filling member 15 is filled into the hollow structural member 200 by the molding using a mold. By the above, a shifting block can be lightened with high rigidity, and the hollow structural member can be reinforced with the filling member. Providing a no-load roller escape passage in the filling member will facilitate the molding more as compared with the case where it is provided at the hard block.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion guide device used for a linear guide portion of various industrial machines such as machine tools, and more particularly to a technique for reducing weight and facilitating molding. Also,
The present invention relates to a moving block and track rail of this linear motion guide device, and methods for manufacturing them.

[0002]

2. Description of the Related Art As a conventional linear motion guide device of this type, for example, there is one shown in FIG. 6 (see Japanese Patent Publication No. 5-36648). That is, the track rail 100,
A moving block 101 movably provided along the track rail 100, and a load rolling element rolling groove 101 provided between the facing surfaces of the moving block 101 and the track rail 100.
and a large number of balls 102 interposed between a and 100a. In this conventional example, the moving block 1
01 The outer circumference was configured by the frame 103 to reduce the weight.

[0003]

However, in the case of the above-mentioned prior art, although the moving block 101 is lightened, the outer peripheral frame 103 has an open cross-sectional shape partially opened by the slit 103a. Has low rigidity, and it will deform significantly when supporting a heavy load,
There is a problem that the feeding accuracy of a supporting object such as a table is deteriorated.

Further, in the case of the prior art, only the frame structure is disclosed, and the structure of the circulation path of the ball 102 supported by the moving block 101 is not described. A major issue was how to form and circulate the circulation path.

As a structure 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).

That is, the outer cylinder 120 with a part cut away
And a shaft 121 inserted into the outer cylinder 120. A large number of balls 122 arranged in the axial direction are interposed between the inner circumference of the outer cylinder 120 and the shaft 121, and the outer cylinder 120 moves linearly along the shaft 121 via the balls 122. There is. The ball 122 is the outer cylinder 120.
Are provided in a plurality of rows in the circumferential direction of the
It circulates through the direction change paths 123 at both ends and the plurality of unloaded ball escape paths 124 provided on the outer peripheral side of the outer cylinder 120. The balls 122 in the load range interposed between the outer cylinder 120 and the shaft 121 are held by the ball holding portions 125 extending along the axial direction at both ends of the ball row.

The ball holding portion 125, the inner peripheral portion 123a of the direction changing passage 123, and the unloaded ball escape passage 124 are integrally formed with the outer cylinder 120 by insert molding.

However, in the above-mentioned conventional integral molding method, when insert molding is performed, as shown in FIG. 7 (c), for example, the outer periphery of the outer cylinder 120 is covered with the first die 126.
Then, the inner circumference of the outer cylinder 120 is brought into close contact with the second mold 127, and the ball holding portion 125 and the unloaded ball escape passage 12 are provided.
Although 4 molding cavities 125a and 124a are formed, it is difficult to bring the inner and outer circumferences of the outer cylinder 120 into close contact with the first and second molds 126 and 127 accurately,
There was a problem that a gap was created between the contact surfaces and burr was generated.

Particularly, the inner circumference of the outer cylinder 120 and the second die 127.
If the molding resin flows between the contact surfaces with and, burrs will be generated on the loaded ball rolling surface, and it is necessary to remove the burrs. However, it is very difficult and practically impossible to remove such a burr that occurs inside the ball holding portions 125, 125.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to achieve a linear motion capable of reducing the weight while maintaining high rigidity and facilitating molding. It is an object of the present invention to provide a method for molding a guide device and a moving block.

[0011]

In order to achieve the above object, in a linear motion guide device of the present invention, a track rail, a moving block provided movably along the track rail, and a moving block. A large number of balls provided between the rolling grooves of the load rolling elements provided between the facing surfaces of the track rails,
An unloaded rolling element escape passage provided in a moving block in parallel with the loaded rolling element rolling groove, and rolling elements in a load range provided between both ends of the moving block and interposed between the loaded rolling element rolling grooves. A side cover provided with a direction change path for changing the direction of the load rolling element escape passage to infinitely circulate the rolling element, and a rolling block located in the rolling groove of the loaded rolling element when the track rail is removed. In a linear motion guide device including a rolling element holding member that prevents the moving block from falling off, the moving block includes a hollow structural member having a closed cross-section structure that forms the entire circumference of the moving block, and the hollow structural member. And a filling member that is filled in the hollow inside of the.

A hard material such as steel having pressure resistance is used for the hollow structural member, and a thermoplastic resin is used for the filling member.
Die casting, granite, aluminum (Al) -based light metal or the like is used. Here, the term "granite" itself means granite, but here it is used as the meaning of a structural material in which epoxy resin and crushed stone such as granite are mixed and cast into a mold.

The loading member of the moving block is provided with an unloaded rolling element escape passage.

At least one of the inner peripheral portion of the rolling element conversion path and the rolling element holding member is integrally formed with the hollow structural member.

The moving block is formed by drawing a 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 inside. It is characterized in that the member is filled.

The filling of the filling member is performed by arranging the hollow structural member in the mold with reference to the rolling groove of the load rolling element and pouring the fluidized molding material.

Another moving block forming method is that a pipe material is drawn out by using a material softer than the pipe material as a core metal, the pipe material is molded into a predetermined cross-sectional shape, and the core metal of the soft material is used as the pipe material. The moving block is formed by plastically deforming in accordance with the cross-sectional shape of, and cutting the pultrusion molded product to a predetermined size.

[0018]

In the present invention, since the hollow structural member has a closed cross-section structure that surrounds the entire circumference of the moving block, it has higher rigidity and higher rigidity than the conventional moving block having a frame structure with an open cross section. Moreover, the weight can be reduced.

Further, the hollow structural member is reinforced by the filling member, and the rigidity is further increased.

When the unloaded rolling element escape passage is provided in the filling member, the molding can be easily performed as compared with the conventional case where the unloaded rolling element escape passage is provided in the hard block.

If the inner peripheral portion of the direction changing path and the rolling element holding member are integrally formed with the hollow structural member, the assembling process can be reduced. In particular, if the filling member, the inner peripheral portion of the direction changing passage, or the rolling element holding member is integrally formed by molding, the working process becomes simple.

If the hollow structural member is molded into a predetermined cross-sectional shape by pulling out the pipe material, the yield is good and the molding can be performed extremely efficiently.

When the filling member is formed by molding, if the hollow structural member is positioned in the mold with reference to the rolling groove of the loaded rolling element, burrs between the rolling groove of the loaded rolling element and the die are formed. Can be prevented.

Here, in order to prevent burrs, it is not necessary for the contact surfaces of the outer cylinder and the mold to be in close contact with each other, and even if there is a gap, infiltration of the molding material can be prevented. Any size will do.

Furthermore, when a soft material is used as the core metal when the pipe material is drawn out, the filling member can be filled at the same time as the drawing, and the number of steps can be further reduced.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments.

1 and 2 show a linear motion guide device according to a first embodiment of the present invention.

The linear motion guide device 1 has a structure in which a moving block 2 is movably supported along a track rail 4 via a number of balls 3 as rolling elements. Rolling elements include rollers having various shapes such as a cylindrical shape and a conical shape.

The moving block 2 has a U-shaped cross section, and is provided with 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.

The moving block 2 is provided with four ball circulation paths 7 for circulatingly guiding a large number of balls 3. In this example, two upper and lower ball circulation paths 7 are formed in the left and right leg portions 5, 5.

Each ball circulation path 7 is a load ball passage 8 of load ball rolling grooves 8a and 8b as load rolling element rolling grooves formed on the opposing surfaces of the moving block 2 and the track rail 4.
The unloaded ball escape passage 10 as an unloaded rolling element escape passage in the unloaded region for returning the ball 3 from one end of the loaded ball passage 8 to the other end side, and the loaded ball passage 8 and the unloaded ball escape passage 10 It is composed of a direction change path 11 that connects the ends at both ends of the moving block 2.

The direction changing passage 11 is a U-shaped passage, the inner peripheral portion 11a of which is integrally joined to the end surface of the movable block 2, and the outer peripheral portion thereof is constituted by a side lid 14 which is separate from the movable block 2. It

The contact angle line L1 showing the direction of the contact angle of the four load balls 3 has a structure inclining 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 the ball rolling grooves 8a, 8 on the moving block 2 side and the track rail 1 side of the load balls 3 in each row.
The same applies to the line connecting the contact point with b.

In this embodiment, a retainer as a rolling element holding member extending along the filling member 15 in which the unloaded ball escape passage 10 of the ball circulation passage 7 is formed, the inner peripheral portion 11a of the direction change passage and the loaded ball passage 8. The part 17 is formed integrally with the moving block 2.

The inner peripheral portion 11a of the direction changing passage is connected to the unloaded ball escape passage 10 as shown in FIG. 1 (b).

Since the unloaded ball escape passage 10 and the ball direction changing passage 11 are integrally formed, the loaded ball escape passage 1
Since a continuous guide surface having no step is formed at the connecting portion between 0 and the ball direction changing path 11, smooth circulation of the ball 3 is guaranteed.

On the other hand, the retainer portion 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 from the moving block 2.
When the moving block 2 is 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 in the load ball passage 8.

In this embodiment, the first retainer is disposed between the upper and lower two load balls 3 of the left and right legs 5, 5 and holds the lower edge of the upper ball 3 and the upper edge of the lower ball 3. Three
0 and the second retainer 3 that holds the upper edge of the upper ball 3
1 and a third retainer 3 for holding the lower edge of the lower ball 3
2 and. The first retainer 30 and the second retainer 31 hold the upper row of balls, and the first retainer 30 and the third retainer 32 hold the lower row of balls. Then, the ball 3 is exposed from between the first to third retainers 30, 31 and 32 and comes into rolling contact with the loaded ball rolling groove 8b on the track rail 4 side.

These first to third retainers 30, 31,
Both ends of 32 are integrally connected to the inner peripheral portion 11a of the direction changing path.

As shown in FIG. 1A, the moving block 2 is filled in a hollow structural member 200 having a closed cross-section structure which constitutes the entire outer circumference of the moving block 2 and the hollow inside of the hollow structural member 200. And a filling member 15.

The hollow structural member 200 is made of a hard material such as steel, and has a first frame 201 that constitutes the upper surface of the horizontal portion 6 of the moving block 2, a second frame 202 that constitutes the lower surface of the horizontal portion 6, and a second frame 202. The left and right third frames 203, 203 extending downward from the left and right side edges of the one frame 201 to form the outer side surface of the leg portion 5, and the lower end extending downward from the left and right side edges of the second frame 202 and the third frame 203. , 203
The left and right fourth parts which are connected to the lower end and which constitute the inner side surface of the leg part 5.
It is composed of frames 204, 204 and fifth frames 205, 205 constituting the lower surface of the leg portion 5. These first to fifth frames 201 to 205 are separated from each other and do not contact each other, and a space having a U-shaped cross section is formed inside.

On the other hand, the filling member 15 is made of a thermoplastic resin,
Die cast, granite, aluminum (Al) -based light metal or the like is used, and the first and second frames 201 and 202 are used.
And the spaces between the third and fourth frames 203 and 204 are closely packed. The filling member 15 can be easily molded by thermoplastic resin molding, die casting, granite casting, or pipe drawing using an Al-based light metal as a core metal.

As described above, the granite is a structural material formed by mixing the epoxy resin and crushed stone such as granite and pouring the mixture into a mold, and has an advantage that damping and thermal deformation are small. . Balls in the moving block 2 circulate in an unloaded state, which causes a problem of ball circulation sound.
The use of granite can improve quietness.

In this embodiment, as the material of the filling member 15, the retainer portion 17 and the ball direction changing passage inner peripheral portion 11a are used.
The same resin material is used, and the filling member 15, the retainer portion 17, and the ball direction changing passage inner peripheral portion 11 a are integrally formed with the hollow structural member 200.

Next, a method of molding this moving block will be described with reference to FIGS.

First, as shown in FIG. 3, the hollow structural member 2
00 is formed by drawing a pipe or forging a pipe.

That is, as shown in FIG. 3A, the pipe material 210 is pulled out through a die 211 having a predetermined shape. The pipe material 210 has a closed cross-sectional shape such as a circle as shown in FIG. The molded product 212 that has been pulled out, as shown in FIG.
It is molded as an elongated body having a cross-sectional shape of 0, and the same figure (d)
As shown in, the hollow structure member 200 having a predetermined size is cut out by cutting the molded product 212 into a predetermined length.

In this way, the complicated shape of the moving block 2 can be extremely easily formed by drawing, and a large cost reduction can be achieved. of course,
It can be formed by press forming as well as drawing or forging.

Next, as shown in FIG. 4, the hollow structural member 200 is filled with the filling member 15 by molding.

FIG. 4 is a schematic configuration diagram of the mold. A cavity 41 for forming a filling member is formed inside the hollow of the hollow structural member 200, and a cavity 42 for forming the retainer 17 on the inner peripheral portion of the leg. However, the cavities 43 for molding the inner peripheral portion 11a of the direction change path are provided at both front and rear ends of the leg portion. The fixed die 44 is provided with a ridge 45 for fitting and positioning the loaded ball rolling groove 8a, and the movable die 46 is provided with a pin 47 for forming the unloaded ball escape passage 10. ing.

At the time of insert molding, as shown in FIG. 7C, the mold 40 is positioned with reference to the loaded ball rolling groove 8a of the moving block 2. In this way, if insert molding is performed with reference to the loaded ball rolling groove 8a,
Since 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,
It is possible to accurately set the relative positional relationship among the loaded ball rolling path 8, the direction changing path 11 and the unloaded ball escape path 10 which form the ball circulation path 7.

In positioning the hollow structural member 200 in the mold 40, the positioning is performed with reference to the loaded ball rolling groove 8a, so that the contact portion with the hollow structural member 200 is the loaded ball rolling groove. 8a only, mold 4
Since the other parts of 0 may be in a non-contact state, precise processing is not required and the manufacturing is very easy.

Thus, the filling of the filling member 15, the formation of the unloaded ball escape passage 10 in the filling member 15, and the formation of the retainer 17 and the ball direction changing passage inner peripheral portion 11a can be performed at the same time.

Thereafter, the ball circulation path 7 of the moving block 2
The ball 3 is stored in and the side lid 14 is attached.

In the present invention, since the filling member 15 is integrally formed with the moving block 2 by insert molding, the unloaded ball escape passage 10 does not need to be drilled, and the manufacturing is very simple. As the insert molding, a die-cast molded product, a sintered metal or the like may be used instead of the resin molding.

As another method of forming the moving block, as shown in FIG. 4, the filling member 15 is not filled by molding, but when the pipe material 210 of FIG. 3 is pulled out,
A material softer than the pipe material 210 is drawn out 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 to obtain a pultruded product with a predetermined size. If cut, the filling member 15 can be filled simultaneously with the drawing process.

When the core metal is used for the drawing and filling in this way, it is necessary to separately form the unloaded ball escape passage.

In FIG. 5A, the left and right fourth frames 204, 204 forming the inner surface of the leg 5 of the moving block 2 are circled in upper and lower two rows corresponding to the upper and lower two ball rolling grooves 8a. The arc-shaped cross section 204a is provided, and the ball rolling groove 8a is formed on the inner circumference of the arc-shaped cross section 204a.

1 except that the structure of the fourth frame 204 and the left and right second retainers 31 of FIG. 1 are integrated through a resin portion 31a joined to the lower surface of the second frame 202. Since the configuration is basically the same, the same components are designated by the same reference numerals and the description thereof is omitted.

FIG. 5B shows a structure in which the contact angle line L2 indicating the contact angle direction of the four load balls 3 is inclined toward the center of the track rail 4 with respect to the horizontal line H. It is a thing. Such a contact structure can be realized by providing the left and right fourth frames 204a forming the inner surface of the leg 5 of the moving block 2 with the arc-shaped cross section 204a in which the ball rolling groove 8a is to be formed.

In this case, the upper and lower arcuate cross-section portions 204
A jetty 204b projecting toward the track rail 4 side is provided between a and 204a, and ball rolling grooves 8a are provided on both upper and lower inclined surfaces of the jetty 204b. A resin retainer 33 is provided at the tip of the jetty 204b to prevent the balls 3 from falling off when the moving block 6 is removed from the track rail 4.

On the other hand, on both right and left side surfaces of the track rail 4, concave grooves 4a are formed corresponding to the jetty 33 on the moving block 6 side, and the moving blocks 6 are formed at the upper and lower even corners of the concave groove 4a.
A ball rolling groove 8b facing the side ball rolling groove 8a is provided, and the ball 3 is rotatably interposed between the moving block 6 and the ball rolling grooves 8a and 8b of the track rail 4.

Other configurations and operations are the same as those of FIG. 1, and the same components are designated by the same reference numerals and their description is omitted.

In the above embodiment, the linear motion guide device having the linear track rail has been described, but it is needless to say that the linear motion guide device which is slidably mounted on the curved track rail can be applied. .

[0065]

As described above, according to the present invention,
Since the hollow structural member has a closed cross-section configuration that surrounds the entire circumference of the moving block, it has higher rigidity, higher rigidity, and lighter weight than the conventional moving block having a frame structure with an open cross section.

Further, the hollow structural member is reinforced by the filling member, and the rigidity is further increased.

If the unloaded rolling element escape passage is provided in the filling member, the molding can be easily performed as compared with the conventional case where the unloaded rolling element escape passage is provided in a hard block.

If the inner peripheral portion of the direction change path and the rolling element holding member are integrally formed with the hollow structural member, the assembling process can be reduced. In particular, if the filling member, the inner peripheral portion of the direction changing passage, or the rolling element holding member is integrally formed by molding, the working process becomes simple.

If the hollow structural member is molded into a predetermined cross-sectional shape by pulling out the pipe material, the yield is good and the molding can be performed extremely efficiently.

When the filling member is formed by molding, if the hollow structural member is positioned in the mold with reference to the rolling groove of the loaded rolling element, burrs between the rolling groove of the loaded rolling element and the die are formed. Can be prevented.

Furthermore, when a soft material is used as the core metal when the pipe material is drawn out, the filling member can be filled at the same time as the drawing and the number of steps can be further reduced.

[Brief description of drawings]

1 shows a linear motion guide device according to an embodiment of the present invention, FIG. 1 (a) is a longitudinal sectional view, and FIG. 1 (b), (c).
FIG. 4 is a diagram showing a configuration of a ball circulation path.

2 is an external perspective view of the linear motion guide device of FIG.

FIG. 3 is a diagram showing an example of a method of 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.

5 (a) and 5 (b) are views showing a linear motion guide device according to another embodiment of the present invention.

FIG. 6 is a sectional view of a conventional linear motion guide device.

FIG. 7 is a diagram showing an insert molding method for 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 passage 10 Unloaded ball escape passage 11 Direction change path 11a Direction change path inner circumference 14 Side lid 15 Filling member 17 Retainer Part 200 Hollow structural member 201-205 1st-5th frame

Claims (6)

[Claims] 1. A track rail, a moving block provided movably along the track rail, and a large number interposed between load rolling element rolling grooves provided between facing surfaces of the moving block and the track rail. Ball, an unloaded rolling element escape passage provided in the moving block in parallel with the loaded rolling element rolling groove, and a load interposed between the loaded rolling element rolling grooves provided at both ends of the moving block. Side cover provided with a direction change path that changes the direction of the rolling elements in the area to the unloaded rolling element escape passage and allows the rolling elements to circulate infinitely; and the rolling lid located in the rolling groove of the loaded rolling element when the track rail is removed. In a linear motion guide device including a rolling element holding member that prevents the moving body from falling off the moving block, the moving block is a hollow structural member having a closed cross-section structure that forms the entire circumference of the moving block outer peripheral portion, Of the hollow structural member A linear motion guide device comprising: a filling member that is filled inside the hollow. 2. The linear motion guide device according to claim 1, wherein the filling member of the moving block is provided with an unloaded rolling element escape passage. 3. The linear motion guide device according to claim 2, wherein at least one of the inner peripheral portion of the rolling element conversion passage and the rolling element holding member is integrally formed with the hollow structural member. 4. A hollow material is molded by drawing a pipe material with a cross-sectional shape of a moving block, cutting the pultrusion molded product into a predetermined length, and then filling a filling member inside the hollow structure. And a method of forming a moving block of a linear motion guide device. 5. The filling of the filling member is performed by arranging the hollow structural member in the mold with reference to the rolling groove of the load rolling element and pouring the fluidized molding material. A method of forming a moving block of the linear motion guide device according to. 6. A pipe material is drawn out by using a material softer than the pipe material as a core metal, the pipe material is molded into a predetermined sectional shape, and the core material of the soft material is plastically deformed in accordance with the sectional shape of the pipe material. A moving block for a linear motion guide device, characterized in that the moving block is formed by cutting the long molded body into a long molded body and cutting the long molded body into a predetermined size.