JP2012237396A - Linear motion guide device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear motion guide device, which can prevent the damage in a seal member and reduce the manufacturing cost by regulating relative movements of an inner seal and an end cap with a simple structure during the movement of a slider.SOLUTION: At an outer end part of a pair of end caps 5a, 5b, engagement parts 14, 14 at cap side are provided. An inner seal 6 is composed of a freely expandable and contractable synthetic resin. A pair of engagement parts 12, 12 at seal side are provided at both ends of a seal body 9 in a direction of expansion and contraction. The value of the free length L2 of the inner seal is set smaller than the distance L1 between the engagement parts of the pair of end caps at end cap side. Then, the inner seal is expanded and the pair of engagement parts at the seal side are engaged to the pair of engagement parts at cap side of the end cap. The expansion is released and the inner seal is elastically contracted to be mounted between the pair of end caps.

Description

  The present invention relates to a linear motion guide device used in the field of industrial machines such as robots and transfer devices.

In general, a linear motion guide device used in a machine tool or the like has a linearly formed guide rail, a slider that moves relative to the longitudinal direction of the guide rail, and a number of rolling guides that are rotatably incorporated in the slider. A slider body having a plurality of rolling element rolling grooves facing the rolling element rolling grooves formed on the left and right side surfaces of the guide rail, and the rolling element rolling grooves and the guide rail of the slider body. A pair of rolling elements arranged at the front end and the rear end of the slider body having a rolling element guide path for guiding the rolling elements that have rolled between the rolling element rolling grooves to a rolling element return passage formed in the slider body. It has a configuration with an end cap.
In such a linear motion guide device, when dust such as cutting powder or dust enters from the upper surface of the guide rail between the rolling element rolling groove of the guide rail and the rolling element rolling groove of the slider body, Since the rolling motion is hindered, it is necessary to seal between the rolling element rolling groove of the guide rail and the rolling element rolling groove of the slider body.

Therefore, it is known to arrange an inner seal member that seals between the rolling element rolling groove of the guide rail and the rolling element rolling groove of the slider body from the inside of the slider.
The inner seal of Patent Document 1 is a long member that extends from one end cap arranged at the front end of the slider body to the other end cap at the rear end of the slider body, and is a seal that is in sliding contact with the upper surface of the guide rail. A lip is provided.

Convex portions are provided at the longitudinal ends of the inner seal, and the inner seal is supported by inserting these convex portions into concave grooves provided in one and the other end caps.
Generally, the inner seal is used as a set with a side seal arranged outside the end cap, and together with the side seal, foreign matter between the rolling element rolling groove of the guide rail and the rolling element rolling groove of the slider body. To prevent the intrusion.

JP 2008-57580 A

However, in the linear motion guide device configured as described above, the convex portion of the inner seal and the concave groove of the end cap are engaged in a state where a gap is generated in the movement direction of the slider, and the inner seal guides when the slider moves. If the gap moves in the direction opposite to the slider moving direction due to friction with the rail, the inner seal and the side seal may be damaged due to mutual interference.
Therefore, when the inner seal and the end cap are assembled so that no gap is generated between the convex portion and the concave groove, interference between the inner seal and the side seal can be prevented. However, since the inner seal and the end cap must be manufactured with high precision, there is a problem in terms of manufacturing cost of the linear motion guide device.

  The present invention has been made paying attention to the above-mentioned unsolved problems of the conventional example, and by restricting the relative movement between the inner seal and the end cap during the movement of the slider with a simple structure, the seal member is damaged. An object of the present invention is to provide a linear motion guide device capable of preventing the manufacturing cost and reducing the manufacturing cost.

In order to achieve the above object, a linear motion guide apparatus according to claim 1 of the present invention is incorporated in a guide rail, a slider that moves relative to the longitudinal direction of the guide rail, and a roll in the slider. A plurality of rolling elements, and the slider has a slider body having rolling element rolling paths, and rolling element circulation portions of the rolling element rolling paths, and the slider body has a front and rear end in the moving direction. In the linear motion guide device comprising: a pair of end caps fixed to the inner surface of the slider body; and an inner seal having a seal lip portion disposed along the moving direction inside the slider body and sliding on the upper surface of the guide rail. A cap-side engaging portion that engages with the inner seal is provided at each outer end of the pair of end caps, and the inner seal is made of a stretchable synthetic resin material. And a pair of sealing side engagement portion at both ends of the reduced direction,
The free length of the inner seal is set to a value smaller than the distance between the cap-side engaging portions of the pair of end caps, and the inner seal is extended so that the pair of seal-side engaging portions becomes the pair of ends. The cap was fitted between the pair of end caps in a state where the cap was engaged with the cap-side engaging portion of the cap and the extension was released and the inner seal was elastically contracted.

The invention according to claim 2 is the linear guide device according to claim 1, wherein the cap side engaging portion is a first engaging recess provided with an engaging inner wall facing the moving direction, The seal-side engagement portion is a first engagement convex portion that protrudes from both end portions of the seal body and has an engagement outer wall that comes into contact with the engagement inner wall when the inner seal is elastically contracted.
Further, according to a third aspect of the present invention, in the linear motion guide device according to the second aspect of the present invention, a second engagement convex portion that partially protrudes toward one of the engagement inner wall and the engagement outer wall is provided. In addition, a second engagement recess is provided on the other of the engagement inner wall and the engagement outer wall and into which the second engagement protrusion provided on one is inserted.

  According to the linear motion guide device of the present invention, the expandable inner seal is extended to engage the pair of seal side engaging portions with the cap side engaging portion of the pair of end caps, and the extension is released to release the inner seal. Since the seal is elastically contracted and attached to the pair of end caps, the inner seal can be attached to the pair of end caps without causing a gap in the slider moving direction. The manufacturing cost can be reduced at the same time as preventing the member from being damaged.

It is a perspective view which shows the structural member of the linear motion guide apparatus which concerns on this invention. It is a principal part cross-section perspective view which shows the member which comprises a slider. It is a figure which shows the inner seal which concerns on this invention. It is the figure which looked at a part of linear motion guide apparatus from the axial direction. It is a figure which shows the engagement state of the cap side engaging part and seal | sticker side engaging part which concern on this invention. It is an AA arrow directional view of FIG. It is a figure which shows the state before mounting | wearing the end cap with the inner seal of 1st Embodiment which concerns on this invention. It is a figure which shows the state just before extending the inner seal of 1st Embodiment which concerns on this invention, and attaching to an end cap. It is a figure which shows the state which mounted | wore the end cap with the inner seal of 1st Embodiment which concerns on this invention. It is a figure which shows the shape of the inner seal and end cap of 1st Embodiment which concerns on this invention. It is a figure which shows the state before mounting | wearing the end cap with the inner seal of 2nd Embodiment which concerns on this invention. It is a figure which shows the state just before extending the inner seal of 2nd Embodiment which concerns on this invention, and attaching to an end cap. It is a figure which shows the state which mounted | wore the end cap with the inner seal of 2nd Embodiment which concerns on this invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.
A linear motion guide device 1 shown in FIG. 1 includes a guide rail 2 and a slider 3 that relatively moves in the longitudinal direction of the guide rail 2.
The slider 3 includes a slider body 4 straddling the guide rail 2, a pair of end caps 5 a and 5 b attached to the front and rear ends of the slider body 4 in the moving direction, and a longitudinal direction in the moving direction of the slider body 4. An inner seal 6 that extends and is arranged inside the slider body 4 (see FIG. 2), a side seal 7 that is fixed to the outside of the pair of end caps 5a and 5b, and an outer side of each side seal 7 And a protector 8 to be fixed.

  As shown in FIG. 3, the inner seal 6 is made of a stretchable synthetic resin material such as a thermosetting elastomer, and includes a seal body 9 formed in a ladder shape and both end portions in the longitudinal direction of the seal body 9. Width of the pair of left and right first arm portions 10a, 10a and second arm portions 10b, 10b, the first arm portions 10a, 10a, the second arm portions 10b, 10b, and the seal body 9 protruding outward in the longitudinal direction from A pair of seal lip portions 11, 11 projecting in the same direction from the direction edge portion, and projecting from the distal ends of the first arm portions 10 a, 10 a and the second arm portions 10 b, 10 b to the opposite side with respect to the seal lip portion 11. The engaging convex part 12 is provided.

  As shown in FIG. 4, one end cap 5 b has a U-shape that is open downward when viewed from the axial direction. The inner upper surface 13 of the end cap 5 b is formed on the upper surface 2 a of the guide rail 2. Face to face. A pair of first engaging recesses 14 is formed on the side of the inner upper surface 13 that is close to the side seal 7, and the pair of second arm portions 10 b and 10 b of the inner seal 6 are formed in these first engaging recesses 14. The 1st engagement convex part 12 which protruded from the front-end | tip part of is engaged.

  As shown in FIG. 5, the first engaging recess 14 includes a pair of first inner walls 14a facing each other in the width direction orthogonal to the moving direction of the end cap 5b, and side walls as shown in FIG. The second inner wall 14b formed between the pair of first inner walls 14a so as to face the outside of the end cap 5b to which the seal 7 is fixed, and the pair of first inner walls 14a so as to face the upper surface 2a of the guide rail 2. And a third inner wall 14c formed therebetween.

As shown in FIG. 6, the first engagement recess 14 of the pair of second arm portions 10 b and 10 b of the inner seal 6 that engages with the first engagement recess 14 is formed on the first engagement recess 14. An engagement surface 12a that abuts the second inner wall 14b in a surface contact state is formed.
The other end cap 5a also has a pair of first engaging recesses 14 formed on the side of the inner upper surface 13 close to the side seal 7 in the same manner as the end cap 5b shown in FIG. The shape of the 1 engaging recess 14 is also the same as that shown in FIGS.

Further, as shown in FIG. 6, the first engagement convex portions 12 of the pair of first arm portions 10a and 10a of the inner seal 6 that engages with the first engagement concave portion 14 of the other end cap 5a are also first An engagement surface 12 a that abuts on the second inner wall 14 b of the engagement recess 14 in a surface contact state is formed.
The engagement inner wall of the present invention corresponds to the second inner wall 14b, the engagement outer wall of the present invention corresponds to the engagement surface 12a, and the free length of the inner seal of the present invention is the distance L2 between the first engagement protrusions. The distance between the cap-side engaging portions of the pair of end caps of the present invention corresponds to the first engaging recess distance L1.

  Here, as shown in FIG. 7, when the pair of end caps 5 a and 5 b are fixed to the front and rear end portions in the moving direction of the slider body 4, the first engagement recesses 14 formed in one end cap 5 a The distance in the longitudinal direction between the second inner wall 14b and the second inner wall 14b of the first engagement recess 14 formed in the other end cap 5b (hereinafter referred to as the first engagement recess distance) is L1. Is set to

Further, the inner seal 6 before being stretched (free length) to which no tensile force is applied in the longitudinal direction includes the engagement surface 12a of the first engagement convex portion 12 formed on the first arm portion 10a, and the second A distance in the longitudinal direction (hereinafter referred to as a distance between the first engagement protrusions) L2 between the engagement surface 12a of the first engagement protrusion 12 formed on the arm portion 10b is a first engagement recess. It is set to a value smaller than the distance L1 (L2 <L1).
As shown in FIG. 8, a tensile force in the longitudinal direction is applied to the inner seal 6 to elastically extend the entire inner seal 6, and the first engagement convex distance L2 ′ is substantially equal to the first engagement concave distance L1. The inner seal 6 is extended until it has the same dimensions.

  Then, in a state where a tensile force is applied to the inner seal 6 such that the distance L2 ′ between the first engagement protrusions is approximately the same as the distance L1 between the first engagement protrusions, the first arm portion 10a of the inner seal 6 is provided. The first engagement convex portion 12 of the inner cap 6 is engaged with the first engagement concave portion 14 of the end cap 5a, and the first engagement convex portion 12 of the second arm portion 10a of the inner seal 6 is engaged with the first engagement of the end cap 5a. After engaging with the recess 14, the application of the tensile force to the inner seal 6 is released.

  As a result, as shown in FIG. 9, when the inner seal 6 is about to elastically contract to the original shape, the first engaging convex portions 12 of the first and second arm portions 10a and 10b are moved to the end cap 5a, The holding force F acts on the second inner wall 14b by moving toward the second inner wall 14b of 5b, and a frictional force is generated between the engaging surface 12a of the first engaging convex portion 12 and the second inner wall 14b. By acting, the inner seal 6 is mounted in a state of straddling the pair of end caps 5a and 5b.

  According to the present embodiment, the telescopic inner seal 6 has the same distance between the first engagement convex portions as the distance L1 between the first engagement concave portions between the pair of end caps 5a, 5b (the first dimension). The distance between the engagement concave portions L1 = the distance between the first convex portions L2 ′) is extended, and the first engagement convex portions 12 provided at both ends in the longitudinal direction of the inner seal 6 are connected to the first end caps 5a and 5b. When the inner seal 6 is elastically shrunk to the original shape after being engaged with each of the engagement recesses, the inner seal 6 is attached to the pair of end caps 5a and 5b so as not to move relative to each other. Therefore, in the present embodiment, the slider 3 is constructed by adopting a simple structure in which the inner seal 6 that is elastically contracted is attached to the pair of end caps 5a and 5b without causing a gap in the moving direction of the slider 3. It is possible to prevent the inner seal 6 and the side seal 7 from being damaged due to mutual interference during the movement.

  Further, when the inner seal 6 attempts to elastically contract to the original shape, the first engagement convex portions 12 provided at both ends in the longitudinal direction of the inner seal 6 are the second of the pair of end caps 5a and 5b. Since the holding force F acts on the second inner wall 14b by moving toward the inner wall 14b, a frictional force acts between the engaging surface 12a of the first engaging convex portion 12 and the second inner wall 14b. The inner seal 6 is securely attached while straddling the pair of end caps 5a, 5b.

  The inner seal 6 is a telescopic member provided with first engagement convex portions 12 at both ends in the longitudinal direction, and the pair of end caps 5a and 5b is also first engaged on the side close to the side seal 7. Since this is a member provided with a recess 14 and the inner seal 6 and the end caps 5a and 5b are not so laborious to manufacture, the manufacturing cost of the linear guide device 1 can be reduced.

Next, FIGS. 10 to 13 show the main part of a second embodiment according to the present invention. The same components as those shown in FIGS. 7 to 9 are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 10, the 2nd engagement recessed part 15 is formed in a part of 2nd inner wall 14b of the 1st engagement recessed part 14 provided in one end cap 5b. Although not shown in FIG. 10, the second engagement recess 15 is also formed in a part of the second inner wall 14b of the first engagement recess 14 provided in the other end cap 5a.

  Further, a second engagement convex portion 16 is formed on a part of the engagement surface 12a of the first engagement convex portion 12 projecting from the distal ends of the pair of second arm portions 10b, 10b of the inner seal 6. . The second engagement convex portion 16 is set to a size capable of entering the second engagement concave portion 15 described above. Although not shown in FIG. 10, the second engagement is also applied to a part of the engagement surface 12 a of the first engagement convex portion 12 protruding from the distal ends of the pair of first arm portions 10 a, 10 a of the inner seal 6. Joint convex part 16 is formed.

  As shown in FIG. 11, the inner seal 6 before extension (free length) to which no tensile force is applied in the longitudinal direction is the engagement surface of the first engagement convex portion 12 formed on the first arm portion 10a. A distance in the longitudinal direction between the second engaging convex portion 16 formed on the first engaging convex portion 12 of the second arm portion 10b and the second engaging convex portion 16 formed on the engaging surface 12a of the first engaging convex portion 12 of the second arm portion 10b. Hereinafter, L3 (referred to as the distance between the second engaging convex portions) is set to a value smaller than the distance L1 between the first engaging concave portions (L3 <L1).

Then, as shown in FIG. 12, a tensile force in the longitudinal direction is applied to the inner seal 6 to elastically extend the entire inner seal 6, and the distance L3 ′ between the second engagement protrusions is the distance L1 between the first engagement recesses. The inner seal 6 is extended until it has substantially the same dimensions.
Then, in a state where a tensile force is applied to the inner seal 6 so that the distance L3 ′ between the second engagement protrusions is substantially the same as the distance L1 between the first engagement protrusions, the first arm portion 10a of the inner seal 6 is provided. The first engagement convex portion 12 of the inner cap 6 is engaged with the first engagement concave portion 14 of the end cap 5a, and the first engagement convex portion 12 of the second arm portion 10a of the inner seal 6 is engaged with the first engagement of the end cap 5a. After engaging with the recess 14, the application of the tensile force to the inner seal 6 is released.

  Thereby, as shown in FIG. 13, when the inner seal 6 is about to elastically contract to the original shape, the first engaging convex portions 12 of the first and second arm portions 10a and 10b are connected to the end cap 5a, By moving toward the second inner wall 14b of 5b, a holding force F acts on the second inner wall 14b, and the second engaging convex portion 16 of the first engaging convex portion 12 is moved to the first engaging concave portion 14. It enters the second engaging recess 15 of the (second inner wall 14b), and the inner seal 6 is mounted in a state straddling the pair of end caps 5a, 5b.

  According to this embodiment, when the inner seal 6 tries to elastically contract to its original shape, the first engaging convex portions 12 provided at both ends in the longitudinal direction of the inner seal 6 are formed by the pair of end caps 5a, The holding force F is applied to the second inner wall 14b by moving toward the second inner wall 14b of the 5b, and the second engaging convex portion 16 of the first engaging convex portion 12 is moved to the first engaging concave portion 14 ( Since the inner seal 6 is prevented from falling off from the pair of end caps 5a and 5b by entering the second engagement recess 15 of the second inner wall 14b), the inner seal 6 straddles the pair of end caps 5a and 5b. It is securely attached in the state.

  DESCRIPTION OF SYMBOLS 1 ... Linear motion guide apparatus, 2 ... Guide rail, 2a ... Upper surface, 3 ... Slider, 4 ... Slider main body, 5a, 5b ... End cap, 6 ... Inner seal, 7 ... Side seal, 8 ... Protector, 9 ... Seal main body DESCRIPTION OF SYMBOLS 10a ... 1st arm part, 10b ... 2nd arm part, 11 ... Seal lip part, 12 ... 1st engagement convex part, 12a ... Engagement surface, 13 ... Inner upper surface, 14 ... 1st engagement recessed part, 14a ... 1st inner wall, 14b ... 2nd inner wall, 14c ... 3rd inner wall, 15 ... 2nd engagement recessed part, 16 ... 2nd engagement recessed part, L1 ... Distance between 1st engagement recessed parts, L2 ... 1st engagement convex Distance between parts, L2 '... Distance between first engaging convex parts, L3 ... Distance between second engaging convex parts

Claims (3)

A slider body having a guide rail, a slider that relatively moves in the longitudinal direction of the guide rail, and a number of rolling elements that are rotatably incorporated in the slider, the slider having a rolling element rolling path A pair of end caps that have rolling element circulation portions of the rolling element rolling path and are fixed to front and rear end portions in the moving direction of the slider body, and are arranged inside the slider body along the moving direction. In a linear motion guide device comprising an inner seal having a seal lip portion sliding on the upper surface of the guide rail,
A cap-side engaging portion that engages with the inner seal is provided on each outer end portion of the pair of end caps,
The inner seal is composed of a stretchable synthetic resin material, and has a pair of seal side engagement portions at both ends in the stretch direction of the seal body,
The free length of the inner seal is set to a value smaller than the distance between the cap-side engaging portions of the pair of end caps,
Extending the inner seal to engage the pair of seal-side engaging portions with the cap-side engaging portions of the pair of end caps;
A linear motion guide device, which is mounted between the pair of end caps in a state where the extension is released and the inner seal is elastically contracted. The cap-side engagement portion is a first engagement recess provided with an engagement inner wall facing the moving direction,
The seal-side engaging portion is a first engaging convex portion that protrudes from both end portions of the seal body and has an engaging outer wall that comes into contact with the engaging inner wall when the inner seal is elastically contracted. The linear motion guide device according to claim 1.   A second engagement convex portion partially protruding toward the other is provided on one of the engagement inner wall and the engagement outer wall, and the other provided on the other of the engagement inner wall and the engagement outer wall. The linear motion guide device according to claim 2, wherein a second engagement concave portion into which the second engagement convex portion enters is provided.

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