Linear guide device

Abstract

To provide a linear guide device capable of sufficiently suppressing intrusion of foreign matters between an end portion in an axial direction of a guide rail and an end portion in an axial direction of a slider even under an environment including much powder dust and the like.SOLUTION: A linear guide device 1 includes: a guide rail 10 having rolling element rolling grooves 11, 12, 13 on both side surfaces 10b and extending in an axial direction; a slider 20 slidably engaged over the guide rail 10; and a dust-proof cover 30 disposed between an axial end portion of the guide rail 10 and an axial end portion of the slider 20, and axially expandable and contractible in accompany with sliding of the slider 20. A cross-section vertical in an axial direction, of the dust-proof cover 30 has a substantially C-shape, and both end portions of the substantially C-shape are substantially kept into contact with regions positioned at lower sides with respect to the rolling element rolling grooves 11, 12, 13, on the corresponding side surface 10b of the guide rail 10.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a linear guide device. [Background technology]

[0002] Linear guide devices used in machine tools and the like are sometimes used in environments where foreign matter such as dust (cutting chips, welding spatters, etc.) is generated. In such an environment, if foreign matter gets into the slider of the linear guide device, it may cause the rolling elements to malfunction, resulting in damage to the linear guide device.

[0003] Conventionally, a side seal or a dust cover is used to prevent foreign matter from entering the slider. FIG. 7 is a schematic side view of a linear guide device according to a conventional example. FIG. 8 is a schematic view of the linear guide device shown in FIG. 7 as viewed from the rear side. In FIG. 7 and FIG. 8, the same reference numerals are used to designate the same structures as those of the linear guide according to the embodiment of the present invention described later, and the description thereof will be omitted. For example, in the conventional linear guide device 201 shown in FIG. 7 and FIG. 8, the axial end (front-rear direction) of the slider 20 is constituted by a side seal 23. In addition, a bellows-shaped dust cover 230 is provided between the axial end of the guide rail 10 and the axial end of the slider 20. The dust cover 230 is shaped to include a cover upper portion 230a located above the guide rail 10 and cover side portions 230b extending downward from both ends of the cover upper portion 230a. Patent Document 1 also describes a dust cover that is for a linear motion table device having two guide rails, but has a bellows-shaped shape in a cross section perpendicular to the axial direction similar to that shown in FIG.

[0004] Patent Document 2 also describes a dust cover that covers an opening on a guide rail between two sliders. The dust cover in Patent Document 2 has an upper surface located above the guide rail, a side surface located to the side of the guide rail, and a bottom surface extending from the side surface toward the guide rail. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2013-167345 A [Patent Document 2] JP 2006-317006 A Summary of the Invention [Problem to be solved by the invention]

[0006] 7 and 8 and Patent Document 1, foreign matter may enter the dust cover from below. To explain in detail, as shown in FIG. 8, in the dust cover 230, the cover side portion 230b is open between the cover side portion 230b and the side surface 10b of the guide rail 10, forming an opening 235. In the dust cover 230 having such a shape, in an environment where there is a particularly large amount of foreign matter such as dust, foreign matter may enter the dust cover 230 from below through the opening 235, and then enter the slider 20.

[0007] Moreover, the dust cover shown in Patent Document 2 is intended to prevent foreign matter from entering the open portion of the guide rail between two sliders, but is not intended to prevent foreign matter from entering between the axial end of the guide rail and the axial end of the slider. Moreover, the dust cover shown in Patent Document 2 is made of metal or resin and is not expandable in the axial direction of the guide rail, so it cannot be used as a dust cover between the axial end of the guide rail and the axial end of the slider.

[0008] The present invention has been made in view of the above problems, and aims to provide a linear guide device that can sufficiently prevent foreign matter from entering between an axial end of a guide rail and an axial end of a slider even in an environment with a large amount of foreign matter such as dust. [Means for solving the problem]

[0009] A linear guide device according to an embodiment of the present invention includes: a guide rail having rolling grooves on both sides thereof and extending in an axial direction; a slider that slidably engages with the guide rail so as to straddle the guide rail; a dust cover attached between the axial end of the guide rail and the axial end of the slider, the dust cover being extendable and contractable in the axial direction in association with sliding of the slider; The dust cover has a substantially C-shaped cross section perpendicular to the axial direction, Both ends of the substantially C-shape substantially abut against portions of the corresponding side surfaces of the guide rail that are positioned below the rolling element rolling grooves. Effect of the Invention

[0010] According to the present invention, a linear guide can be provided that can sufficiently prevent the intrusion of foreign matter between the axial end of the guide rail and the axial end of the slider, even in an environment with a lot of foreign matter such as dust. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic side view of a linear guide device according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram of the linear guide device shown in FIG. 1 as viewed from the rear side. [Diagram 3] FIG. 3 is a schematic diagram showing a modified example of the linear guide device shown in FIG. [Figure 4] FIG. 4 is a schematic side view of a linear guide device according to a second embodiment of the present invention. [Diagram 5] FIG. 5 is a schematic diagram of the linear guide device shown in FIG. 4 as viewed from the rear side. [Figure 6] FIG. 6 is a schematic diagram of a guide rail according to a second embodiment of the present invention. [Figure 7] FIG. 7 is a schematic side view of a linear guide device according to a conventional example. [Figure 8]FIG. 8 is a schematic diagram of the linear guide device shown in FIG. 7 as viewed from the rear side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the linear guide device according to each embodiment of the present invention will be described with reference to the drawings. Note that in the following description, explanations of members having the same reference numbers as members already described will be omitted as appropriate. Also, the dimensions of each member shown in the drawings are for convenience of explanation and may differ from the actual dimensions of each member.

[0013] [First embodiment] Fig. 1 is a schematic side view of a linear guide device 1 according to a first embodiment of the present invention. Fig. 2 is a schematic view of the linear guide device 1 shown in Fig. 1 as viewed from the rear side. Note that the left side of the line segment m in Fig. 2 shows a state in which the mounting plate 32 is illustrated, and the right side of the line segment m shows a state in which the mounting plate 32 is not illustrated.

[0014] In this specification, the terms "front-rear direction," "up-down direction," and "left-right direction" will be referred to as appropriate. The "front-rear direction" is a direction that includes the front and rear directions shown in FIG. 1. The "front-rear direction" is sometimes referred to as the "axial direction" of the guide rail 10. The "up-down direction" is a direction that includes the upward and downward directions shown in FIG. 1. The "left-right direction" is a direction that includes the left and right directions shown in FIG. 2. These directions are relative to each other and are set for the convenience of explanation, and do not limit the present invention.

[0015] The linear guide device 1 shown in Fig. 1 and Fig. 2 includes a guide rail 10, a slider 20, and a dust cover 30. The guide rail 10 extends along the axial direction. Furthermore, rolling element rolling grooves 11, 12, and 13 extending along the axial direction are formed on both side surfaces 10b of the guide rail 10. A cage relief groove 14 is formed between the rolling element rolling grooves 12 and 13 so that the cage (not shown) does not interfere with the circulation of the rolling elements (not shown).

[0016] The slider 20 is slidably engaged with the guide rail 10 so as to straddle the guide rail 10. The slider 20 has a slider body 21, an end cap 22, and a side seal .

[0017] The slider body 21 has a plurality of slider side rolling grooves (not shown) that face the rolling element rolling grooves 11, 12, and 13, respectively. The slider body 21 also has a plurality of rolling element return paths (not shown) and a plurality of rolling elements (not shown). The rolling elements may be balls or rollers. The end caps 22 are provided at both ends of the slider body 21 in the axial direction. The end caps 22 are provided with a direction change path. A circulation path for the rolling elements is formed by the rolling element rolling grooves 11, 12, and 13, the slider side rolling groove, the rolling element return path, and the direction change path. The plurality of rolling elements roll in a circulating manner within the circulation path, so that the slider 20 is slidably guided on the guide rail 10.

[0018] The side seals 23 are disposed axially outward of the end caps 22 to prevent foreign matter from entering the slider 20. In other words, the side seals 23 are disposed at both axial ends of the slider 20. That is, in this embodiment, the axial ends of the slider 20 are the side seals 23.

[0019] The dust cover 30 is attached between the axial end of the guide rail 10 and the axial end of the slider 20. In the example of Fig. 1, a fastener 33 arranged at the rear end of the guide rail 10 and a rear mounting plate 32 of the dust cover 30 are fixed by a fixing device (e.g., a screw) 34, and a side seal 23 arranged at the rear end of the slider 20 and a front mounting plate 32 of the dust cover 30 are fixed by the fixing device 34, thereby attaching the dust cover 30. It is preferable that the dust cover 30 is also attached between the front end of the guide rail 10 and the front end of the slider 20.

[0020] The dustproof cover 30 has a bellows portion 31, and can expand and contract in the axial direction as the slider 20 slides. As shown in Fig. 2, the dustproof cover 30 includes a cover upper portion 30a located above the upper surface 10a of the guide rail 10, cover side portions 30b extending downward from both left and right ends of the cover upper portion 30a, and a cover bottom portion 30c extending from the lower end of the cover side portion 30b to the opposing side surface 10b of the guide rail 10. That is, the cross section of the dustproof cover 30 perpendicular to the axial direction is substantially C-shaped.

[0021] Both ends of the substantially C-shape (in this embodiment, the tips of the cover bottom 30c) substantially abut against portions of the corresponding side surface 10b of the guide rail 10 that are located below the rolling element rolling grooves 11, 12, and 13. As a result, a substantially closed space (space s) including the rolling element rolling grooves 11, 12, and 13 is formed by the dust cover 30 and the upper surface 10a and both side surfaces 10b of the guide rail 10.

[0022] Here, substantially abutting is a concept including a state in which the objects in abutment are close enough to each other that they rub against each other due to the sliding of the slider 20 and the accompanying movement and expansion and contraction of the dust cover 30.

[0023] When the clearance between the tip of the cover bottom 30c and the side surface 10b is narrow, the dustproof performance is high. On the other hand, when the clearance is narrow, friction between the tip of the cover bottom 30c and the side surface 10b may deteriorate the sliding property of the dustproof cover 30 or the tip of the cover bottom 30c may be easily worn.

[0024] When there are multiple rolling element rolling grooves, the positions at which the ends of the approximately C-shape abut may be lower than the lowest rolling element rolling groove. Therefore, in this embodiment, the positions at which the ends of the approximately C-shape abut may be lower than the rolling element rolling groove 13 on the side surface 10b. Note that, although the linear guide device 1 of this embodiment has four rows, the number of rows is not limited to this.

[0025] The fastener 33 is made of, for example, sheet metal. The fastener 33 has a cover mounting portion 33a, a screw hole 33b, and a plate-shaped main body 33c. The cover mounting portion 33a stands upright from the plate-shaped main body 33c. The screw hole 33b is formed in the cover mounting portion 33a. The mounting plate 32 and the cover mounting portion 33a are fixed to each other by the screw hole formed in the mounting plate 32, the screw hole 33b, and the fastener 34.

[0026] The plate-shaped body 33c has a substantially C-shaped cross section perpendicular to the axial direction. The plate-shaped body 33c straddles the upper surface 10a of the guide rail 10 and is fixed to the axial end of the guide rail 10 by engaging both ends of the substantially C-shape with the corresponding retainer clearance grooves 14 of the side surface 10b.

[0027] [Variations] The fastener 33 may have a conventionally known structure. Alternatively, as shown in Fig. 3, the dust cover 30 may be directly attached to the guide rail 10 without using the fastener 33. In the example of Fig. 3, the attachment plate 32 and the guide rail 10 are fixed to each other by a screw hole formed in the attachment plate 32, a screw hole 15 formed in the end face of the guide rail 10 on the rear side, and a fixing device 34.

[0028] In the first embodiment, the tip of the cover bottom 30c of the dust cover 30 is approximately in contact with the side surface 10b of the guide rail 10, but the manner of contact is not particularly limited as long as it is possible to form an approximately closed space including the rolling element rolling grooves 11, 12, and 13 therein. For example, a configuration may be adopted in which a protruding portion is provided so as to extend along the axial direction by protruding a portion located below the rolling element rolling grooves 11, 12, and 13 on both side surfaces 10b of the guide rail 10, and the lower end of the protruding portion approximately contacts the upper end of the approximately C-shaped end portion.

[0029] [Second embodiment] Next, a linear guide device 101 according to a second embodiment of the present invention will be described with reference to Figures 4 to 6. The linear guide device 101 according to the second embodiment can employ a similar configuration to that of the first embodiment, except that a guide rail 110 is used instead of the guide rail 10. Therefore, hereinafter, differences in the structure of the guide rail will be mainly mentioned.

[0030] Fig. 4 is a schematic side view of a linear guide device 101 according to a second embodiment of the present invention. Fig. 5 is a schematic view of the linear guide device 101 shown in Fig. 4 as viewed from the rear side. Fig. 6 is a schematic view of a guide rail 110 according to the second embodiment of the present invention.

[0031] 4 to 6, a dustproof cover groove 16 is provided on both side surfaces 110b of the guide rail 110 at a position located below the rolling element rolling grooves 11, 12, and 13. Both ends of the approximately C-shape of the dustproof cover 30 (in this embodiment, the tip of the cover bottom portion 30c) are configured to be located within the dustproof cover groove.

[0032] The vertical length of the dust cover groove 16 is not particularly limited, but is preferably slightly longer than the vertical length of the tip of the cover bottom 30c. If the vertical clearance is small, the sliding properties of the dust cover 30 may deteriorate, and the tip of the cover bottom 30c may be easily worn. Also, if the vertical clearance is large, the tip of the cover bottom 30c may easily come off the dust cover groove 16.

[0033] The depth (length in the left-right direction) of the dustproof cover groove 16 is not particularly limited. If the depth of the dustproof cover groove 16 is shallow, the tip of the cover bottom 30c may easily come off the dustproof cover groove 16. If the depth of the dustproof cover groove 16 is deep, the sliding property of the dustproof cover 30 may deteriorate. In the second embodiment, when the clearance in the up-down direction is within a preferred range or when the depth of the dustproof cover groove 16 is within a preferred range, it may be said that the dustproof cover groove 16 and the tip of the cover bottom 30c are substantially in contact with each other.

[0034] Although the embodiments and modifications of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments and modifications, and can be modified, improved, etc. as appropriate. The elements included in the embodiments and modifications can be combined with each other, and the result of such combination also forms part of the embodiment of the present invention.

[0035] As described above, the present specification discloses the following: (1) a guide rail having rolling grooves on both sides thereof and extending in the axial direction; a slider that slidably engages with the guide rail so as to straddle the guide rail; a dust cover attached between the axial end of the guide rail and the axial end of the slider, the dust cover being extendable and contractable in the axial direction in association with sliding of the slider; The dust cover has a substantially C-shaped cross section perpendicular to the axial direction, Both ends of the substantially C-shape substantially abut against portions of the corresponding side surfaces of the guide rail that are located below the rolling element rolling grooves. Linear guide device. According to this linear guide device, even in an environment with a lot of foreign matter such as dust, it is possible to sufficiently prevent foreign matter from entering between the axial end of the guide rail and the axial end of the slider. Specifically, since a substantially closed space containing the rolling element rolling grooves therein can be formed by the dust cover and the upper surface and both side surfaces of the guide rail, it is possible to sufficiently prevent foreign matter from entering the slider even in an environment with a lot of foreign matter such as dust.

[0036] (2) A groove for a dust cover is provided on each side surface of the guide rail at a position lower than the rolling element rolling groove, The tips of both ends of the approximately C-shape are located in the groove for the dust cover. The linear guide described in (1) above. According to this linear guide device, the tips of both ends of the approximately C-shape are positioned in the groove for the dust cover, thereby improving the dustproof performance and making it difficult for the dust cover to come off. Also, even if a certain amount of clearance is provided between the tips of both ends of the approximately C-shape and the groove for the dust cover in order to improve the sliding property of the dust cover, it is possible to maintain high dustproof performance. [Explanation of symbols]

[0037] 1,101,201: Linear guide device; 10,110: Guide rail; 10a: Upper surface; 10b: Side surface; 11,12,13: Rolling body rolling groove; 14: Retainer clearance groove; 15: screw hole; 16: groove for dust cover; 20: slider; 21: slider body; 22: End cap, 23: Side seal, 30,230: Dust cover, 30a, 230a: cover upper part, 30b, 230b: cover side part, 30c: cover bottom part, 31: bellows part, 32: mounting plate, 33: fastener, 33a: cover mounting part, 33b: screw hole, 33c: plate-shaped main body, 34: fixing tool, 235: opening part, S: Space

Claims

1. a guide rail having rolling grooves on both sides thereof and extending in an axial direction; a slider that slidably engages with the guide rail so as to straddle the guide rail; a dust cover attached between the axial end of the guide rail and the axial end of the slider, the dust cover being extendable and contractable in the axial direction in association with sliding of the slider; The dust cover has a substantially C-shaped cross section perpendicular to the axial direction, Both ends of the substantially C-shape substantially abut against portions of the corresponding side surfaces of the guide rail that are located below the rolling element rolling grooves. Linear guide device.

2. A groove for a dust cover is provided on each side surface of the guide rail at a position below the rolling element rolling groove, The tips of both ends of the substantially C-shape are located within the groove for the dustproof cover. The linear guide device according to claim 1 .

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