JP2004353698A - Linear motion guide device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent the leakage of a lubricant supplied to an oil passage without keeping the flatness of a slide body end face on the whole area. <P>SOLUTION: A fitting recessed part 8 is formed along an oil passage forming position of a joint face opposite to a slider body 2, of an end cap 3. An independent member 6 made out of a material of a hardness lower than that of the end cap 3 is fitted in the recessed part 8. A groove for the oil passage is formed on the joint face to the fitting recessed part 8, of the independent member 6, and projecting parts 15 extended along the groove for the oil passage, are respectively formed at both sides of the groove. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a linear motion guide device, and more particularly to a linear motion guide device suitable for use in a place where poor lubrication is expected in a bad environment or where a lubricant is washed away by a cutting fluid or the like.
[0002]
[Prior art]
In a conventional linear motion guide device, end caps are joined to both end surfaces in the axial direction of a slider body having a substantially U-shaped cross section which relatively moves along a guide rail by bolting. The end of the load rolling path formed between the guide rail side surface and the inner peripheral surface of the slider main body and the end of the return path penetrating the slider main body are formed in a semicircular arc shape formed in each end cap. The infinite circulation path is formed by being connected by the direction change path, and a plurality of rolling elements are arranged in the infinite circulation path.
[0003]
Here, the semicircular turning path is formed by fitting a return guide into a turning path recess formed in the end cap joint surface.
Then, as described in the prior art document 1 and the prior art document 2, an oil supply groove is formed along the oil passage forming position on the joint surface of the end cap joined to the slider body end face, and the oil supply groove and the slider body end face ( An oil passage is formed with the joint surface on the slider body side). Here, the oil passage communicates with an oil supply passage formed in the return guide, and the lubricant is supplied to the rolling element row in the endless circulation passage through the oil supply passage.
[0004]
An example in which the rolling element is a roller is described in Patent Literature 3. However, in the configuration of the oil passage, an oil supply groove is formed along the oil passage formation position with respect to the joining surface of the end cap. A closed oil passage is formed by the oil supply groove and the end surface of the slider body (the joint surface on the slider body side).
[0005]
[Patent Document 1]
JP-A-8-114224 [Patent Document 2]
Japanese Utility Model Publication No. 6-2024 [Patent Document 3]
JP-A-6-43345
[Problems to be solved by the invention]
Usually, the end cap is manufactured at low cost by plastic molding, but it is difficult to form a complete flat surface of the resin component due to sink and shrinkage at the time of molding. Therefore, even if the end surface of the slider body made of steel is flattened by cutting, it is generally fixed to the end surface of the slider body with a partially provided screw. Therefore, it is difficult to form an oil passage formed by the two in a completely closed space. For this reason, assuming lubrication using oil with high fluidity, the lubricant supplied to the oil passage originally leaks through the gap formed between the slider body end face and the end cap joint face and causes capillary action, May flow out of the route other than the route. Therefore, when used in a place where poor lubrication is expected in a poor environment or where the lubricant is washed away by a cutting fluid or the like, there is a possibility that poor lubrication may be caused early. In particular, the portion where the accuracy is difficult to be obtained in the above-mentioned joining surface portion of the end cap is near the center of the downward U-shape.
[0007]
Also, depending on the specifications, there were places where the oil easily flows and places where the oil does not easily flow due to the influence of gravity even in the attitude of the slider. In this case, as long as the highly fluid oil is held in the oil passage, the lubricant spreads to each raceway surface as it is, but if the holding performance is poor due to the gap between the joint surfaces as described above, the lubrication is also poor. Is expected to come out.
[0008]
Here, as described in Japanese Utility Model Publication No. 6-39144, an oil supply groove is formed on the joint surface of the end cap, and the joint surface extends along the oil supply groove to a position close to the recess of the ball circulation path. It is disclosed that a minute mountain-shaped band-shaped projection is integrally formed. In this case, however, it is necessary to provide a flatness more than required in a cutting process of an end surface (joining surface with an end cap) of a slider body made of steel. This leads to higher costs.
SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to effectively prevent leakage of lubricant supplied to an oil passage without maintaining flatness of an end surface of a slider body over the entire area. It is an object of the present invention to provide a linear motion guide device that can perform the following.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has a guide rail having a track surface extending in the axial direction, and has a track surface opposed to the track surface of the guide rail and straddles the guide rail so as to be relatively movable. A slider main body, end caps attached to both axial end surfaces of the slider main body, a load track path formed by the opposed raceway surfaces, a return path formed by the slider main body, and the end caps formed by the end caps. A plurality of rolling elements moving in an endless circulation path comprising a direction change path connecting the load section orbital path and the return path, and supplying lubricant to a row of rolling elements in the endless circulation path. In the linear guide device in which the oil passage is formed in the end cap,
A fitting recess extending along at least a part of the oil passage forming position is formed on a surface of the end cap facing the slider body, and the end cap is fitted into the fitting recess and has the same material hardness as the end cap. Or a low separate member, forming a groove for an oil passage in at least one of the joint surfaces of the fitting recess and the separate member facing each other, and forming the groove for at least one of the opposed joint surfaces. One or two or more protruding portions extending along the oil passage groove are provided.
[0010]
According to the present invention, at least a portion of the oil passage formed in the end cap is formed by the fitting recess of the end cap and the separate member fitted in the recess, so that the flatness of the end surface of the slider body is improved. Need not be maintained for all areas.
Further, a groove for an oil passage is formed at a joint surface position of the fitting recess and the separate member facing each other, that is, by forming an oil passage in a closed space formed by both parts, Lubricant leakage is prevented.
[0011]
At this time, when one or more protrusions formed along the groove for the oil passage abut against and join the opposing joint surfaces, the other member side, which is the lower hardness material, If the hardness is the same, at least the protruding part is elastically deformed, so that even if there is distortion such as sink in molding, a closed space is surely formed on the joint surface between the end cap and another member And leakage from the oil passage can be prevented.
[0012]
Next, the invention described in claim 2 is characterized in that the depth of the fitting recess and the thickness of the separate member in the fitting direction are equal or substantially equal to the structure described in claim 1. It is assumed that.
According to the present invention, by joining the end cap to the end face of the slider main body, it is ensured that the oil passage groove is sealed with the projection.
[0013]
Next, according to a third aspect of the present invention, in the configuration described in the first or second aspect, the direction change path of the end cap is formed by a return guide formed in a direction change path forming groove formed in the end cap. In the linear motion guide device formed by fitting, the separate member and the return guide are integrally formed.
[0014]
Next, according to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the lubricant is a lubricating oil and one of the oil passages formed in the end cap. A lubricant holding member is interposed in the portion.
The lubricant holding material is not limited to the oil passage position of the portion formed by the separate member, but may be an oil passage position formed by the groove of the end cap and the end face of the slider body. When the lubricating oil is located at the oil passage position formed by the groove of the end cap and the end face of the slider body, the leakage of the lubricating oil from that position is maintained by holding the highly fluid lubricant on the lubricant holding material. It leads to reduction.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
In the present embodiment, a roller is exemplified as a rolling element, and a linear motion guide device having a total of four rolling element trajectory rows of two right and left rows will be described as an example. However, it is not limited to this.
[0016]
First, the configuration will be described. As shown in FIG. 1, a slide unit 4 having a U-shaped cross section straddles a guide rail 1 extending in the axial direction, and the slide unit 4 is guided by the guide rail 1 to move relative to each other. It is movable. The slide unit 4 includes at least a slider body 2 and an end cap 3 which is in contact with and joined to an axial end face of the slider body 2. For the sake of explanation, the left and right portions of the U-shaped cross section of the end cap 3 are referred to as legs 3b, and the upper portion connecting the left and right legs 3b is referred to as a base 3a.
[0017]
On the left and right side surfaces of the guide rail 1, two rail-side track grooves 1 a extending in the axial direction are formed, and on the inner peripheral surface of the slider body 2, the rail-side track grooves 1 a are arranged to face the rail-side track grooves 1 a. The slider-side orbital grooves are respectively formed, and each of the opposing orbital grooves forms a respective load-portion orbital path. Further, a rolling element return path is formed in the slider main body 2 by a through hole parallel to each load section orbital path. Further, the end cap 3 is formed with a semi-arc-shaped turning path for connecting the end of each corresponding load track path and the end of the rolling element return path to communicate with each other, so that four endless tracks are formed. A circulation path is formed, and a plurality of rolling elements arranged in the infinite circulation path roll in the infinite circulation path with the relative movement of the slider body 2.
[0018]
Here, in the direction change path, a direction change path concave portion 9 having an arc-shaped bottom surface is formed with respect to a joining surface of the end cap 3 to the slider body 2 (hereinafter sometimes simply referred to as a joining surface). It is formed by fitting the return guide 7 into the direction changing path concave portion 9. In the case where the rolling elements are rollers, the two turning paths formed in each leg are arranged in a dashed (x) shape. When the rolling element is a ball, it is not arranged in a skid shape.
[0019]
An oil passage is formed on the joint surface 3A of the U-shaped end cap 3 along the joint surface 3A as in the conventional case. That is, as shown in FIG. 2, the oil passage includes a horizontal portion extending horizontally along the base portion 3a of the end cap 3, and a vertical portion communicating with the horizontal portion and vertically extending the left and right legs 3b. The vertical portion communicates with an oil passage (oil supply passage 11) formed in the return guide 7.
[0020]
In the present embodiment, the oil passage includes the end cap 3 and the separate member 6. Further, in the present embodiment, the separate member 6 is integrally formed with the return guide 7.
The structure will be described. As shown in FIG. 3 (b), a fitting recess 8 is formed on the joint surface 3A of the end cap 3 along the oil passage forming position so as to extend the base portion in the lateral direction and extend each leg position in the vertical direction. Is formed, and the fitting recess 8 communicates with the direction changing passage recess 9.
[0021]
Further, as shown in FIG. 3A and FIG. 4 as viewed from the slider main body 2, a separate member 6 having a shape capable of being fitted is provided. The separate member 6 and the return guide 7 fitted into the direction changing path concave portion 9 are integrally formed.
An oil passage groove 10 that forms an oil passage is formed on the joining surface 6A of the separate member 6 facing the end cap 3 along the extending direction of the separate member 6. In the present embodiment, the oil supply passage 11 communicating with the oil passage groove 10 is also formed on the surface facing the end cap 3 with respect to the return guide 7 integrated with the separate member 6.
[0022]
As a result, the axial end surface (slider-side joining surface) of the slider body 2 is not directly involved in the formation of the oil passage.
In the drawing, reference numeral 12 denotes a mounting hole provided in the end cap 3 of the oil supply nipple, and reference numeral 13 denotes a bolt mounting hole for bolting the end cap 3 to the slider body 2.
[0023]
Further, as shown in FIGS. 3A, 4 and 5, the joint surface of the separate member 6 extends on both sides of the oil passage groove 10 along the extending direction of the groove 10. Each of the protrusions 15 is formed. In addition, as shown in FIG. 5, the tip of the convex portion 15 is chamfered at a corner and is rounded. The protrusions 15 are also formed on both sides of the oil supply passage 11 of the return guide 7.
[0024]
Here, the bottom surface (joint surface with the separate member 6) of the fitting recess 8 is formed flat as shown in FIG. The thickness (dimension in the fitting direction) of the separate member 6 is set to be equal to or substantially equal to the depth of the fitting recess 8. That is, assuming that the projection height of the projection 15 is T, the depth of the fitting recess 8 is D, and the thickness H of the separate member 6, the following values are set. In addition, it is sufficient that the protrusion height T of the protrusion 15 is, for example, about 0.2 mm.
[0025]
DT <H <D + T
The material of the separate member 6 is formed of a material having a lower hardness than the material of the end cap 3. Here, in order to prevent lubricant from leaking from the oil passage, it is desirable to join soft elastic materials together. However, since the end cap 3 has a mechanism for picking up the rolling elements 5, it is necessary to be made of a material having excellent impact resistance due to the collision of the rolling elements 5. In addition, polyamide (66 nylon) or polyacetal (such as Delrin made by DuPont or Tenac made by Asahi Kasei) is often used because a predetermined material strength is absolutely necessary when the slider unit 4 moves at high speed. . Therefore, it is desirable that the separate member 6 be a rubber-based material or an elastomer material that is an oil-resistant soft elastic material. For example, Toyobo's Perprene or Toray Dupont's Hytrel can be used. Even with these materials, the lubricant swells, and by swelling, it is possible to join with the end cap 3 without gaps. The separate member 6 may be formed from the same material as the end cap.
[0026]
In the linear motion guide device having the above configuration, when the end cap 3 is bolted and joined to the end surface of the slider body 2 in a state where the separate member 6 is fitted in the fitting recess 8, the separate bolt is used. The separate member 6 is pushed into the fitting recess 8 until the surface of the body member 6 on the slider body 2 side is flush with the joining surface of the end cap 3. As a result, the joining surface 8 A of the fitting recess 8 is formed. And the joint surface 6A of the separate member 6 are joined together, and the respective protrusions 15 formed on both sides of the oil passage groove 10 are pressed against the joint surface (bottom surface) of the fitting recess 8 and elastically deformed. Thus, both sides of the oil passage groove 10 are sealed with a predetermined contact pressure. When the convex portion is fitted on the concave portion 8 side as described later, the joint surface portion of the separate member 6 that contacts the convex portion is elastically deformed to seal.
[0027]
That is, in this embodiment, since the oil passage is not formed at the end surface of the slider body 2 made of steel or the like, the end surface of the slider body 2 having high rigidity has a predetermined accuracy or more for preventing leakage of the lubricant. There is no need to perform finish processing to ensure flatness, and as shown in FIG. 2, lubricant is supplied to the oil supply passage of the return guide 7 through an oil passage formed by the end cap 3 and the separate member 6. You. Further, since the oil supply path of the return guide 7 is also formed on the surface on the end cap 3 side, the lubricant is supplied to the rolling elements 5 passing through the direction change path without leaking.
[0028]
In this embodiment, the joint surface of the fitting recess 8 of the end cap 3 and the joining surface of the separate member 6 fitted to the fitting recess 8 (the portion of the oil passage groove 10) are formed. The formation of the closed space prevents leakage of the lubricant from the oil passage. That is, as compared with the conventional joining of the end face of the slider body 2 having high rigidity and the end cap 3 having predetermined rigidity, the separate member 6 made of a soft elastic material and the rigidity Since the joint between the end cap 3 and the lower end cap, the degree of adhesion of the joint surface is further improved, and the closed space is formed by fitting, so that distortion such as shrinkage can be slightly generated by molding. Even if it does, leakage of the lubricant is prevented.
[0029]
Further, since both sides of the oil passage are sealed by the elastically deformed convex portions 15, leakage of the lubricant from the oil passage is reliably prevented.
Here, in the above embodiment, the groove serving as the oil passage is formed in the separate member 6 and the joint surface of the fitting recess 8 of the end cap 3 corresponding to the joint surface is formed in a flat shape. It is possible to provide a groove or a convex portion for the oil passage in the hole, however, the concave surface of the fitting concave portion 8 becomes complicated, and it is difficult to obtain the dimensional accuracy of the end cap 3 having the raised portion of the rolling element 5 and the like. Become. Therefore, it is preferable to provide an oil passage groove or a protrusion 15 on the separate member 6 side.
[0030]
In the above description, the case of one protruding portion 15 is illustrated. However, as shown in FIG. 6, two protruding portions 15 or more than three protruding portions 15 may be formed.
Further, an oil passage groove and a convex portion are provided in the fitting concave portion 8, and an oil passage groove is formed on the fitting concave portion 8 side and a convex portion is formed on the separate member 6 side. A projection may be formed on the fitting recess 8 side, and an oil passage groove may be formed on the separate member 6 side. Furthermore, both the joint surfaces 6 and 8 may be provided with a convex portion and an oil passage groove. Further, the protrusions 15 located on both sides of the oil passage groove 10 are not limited to both sides of the groove 10 but may be only one side.
[0031]
Further, in the above embodiment, the case where the separate member 6 and the return guide 7 are integrally formed is exemplified, but the invention is not limited to this. For example, as shown in FIG. 7, the separate member 6 and the return guide 7 may be configured by separate members 6. FIG. 7 shows an example in which the oil supply path of the return guide 7 is formed on the surface on the slider body 2 side as in the related art, but may be provided on the end cap 3 side as described above. Further, the case where the separate member 6 is configured as one member is illustrated, but the separate member 6 may be divided into a plurality along the oil passage forming direction.
[0032]
Further, it is not necessary to constitute the entire oil passage except for the return guide 7 with the separate member 6, and as shown in FIGS. 8 to 10, only the oil passage portion at the base 2A position is separated as described above. The oil passage may be formed by using the member 6, and a part of the oil passage may be formed by the oil passage groove 10 formed in the end cap 3 and the end face of the slider body 2 as in the conventional case.
[0033]
Further, as shown in FIG. 11, when a fluid oil is used as a lubricant, the fluid oil is absorbed into a part of the oil passage in order to enhance the retention of the fluid lubricant. A high performance oil retaining member such as pp felt or sponge may be inserted into the oil passage groove. When the lubricant is pumped, it is preferable to put the lubricant into a portion having a size larger than the oil passage shape at the end so that the lubricant is not fed into the raceway surface as foreign matter. In FIG. 11, the oil passage is located at the oil passage position formed by the separate member 6, but the oil passage is formed without using the separate member 6 as shown in FIG. 8 (reference numeral in FIG. 8). If there is (part A), the lubricant holding material may be interposed in the oil passage groove of that part.
[0034]
【The invention's effect】
As described above, it is possible to effectively prevent the leakage of the lubricant from the oil passage that supplies the lubricant to the rolling elements of the infinite circulation path without providing the flatness over the entire end surface of the slider body having high rigidity. There is an effect that can be prevented.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a linear motion guide device according to an embodiment based on the present invention.
FIG. 2 is a view of an end cap and a separate member according to an embodiment of the present invention as viewed from a slider main body 2 side.
FIG. 3 is a diagram illustrating fitting of an end cap and a separate member according to an embodiment of the present invention.
FIG. 4 is a view of a separate member according to the embodiment of the present invention as viewed from a slider body side.
FIG. 5 is a cross-sectional view showing a separate member according to the embodiment of the present invention.
FIG. 6 is a view for explaining another example of the convex portion according to the embodiment based on the present invention.
FIG. 7 is a diagram illustrating another example of a separate member according to the embodiment of the present invention.
FIG. 8 is a diagram illustrating another example of the separate member according to the embodiment of the present invention.
FIG. 9 is a view showing another example of the separate member according to the embodiment of the present invention, as viewed from an end cap side.
FIG. 10 is a cross-sectional view showing another example of the separate member according to the embodiment based on the present invention.
FIG. 11 is a diagram illustrating an example in which a lubricant holding material according to the embodiment of the present invention is used.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 guide rail 2 slider body 3 end cap 3A joining surface 5 rolling element 6 separate member 6A joining surface 7 return guide 8 fitting recess 8A joining surface 9 direction changing recess 10 oil passage recess 11 oil supply passage 15 projection

Claims (4)

A guide rail having a raceway surface extending in the axial direction, a slider body having a raceway surface facing the raceway surface of the guide rail and straddling the guide rail so as to be relatively movable, and both axial end surfaces of the slider body And a load path formed by the opposed raceway surfaces, a return path formed in the slider body, and the load path formed by each end cap and connecting the load path and the return path. A plurality of rolling elements moving in an endless circulation path comprising a direction change path, and an oil path for supplying lubricant to a row of rolling elements in the endless circulation path is formed in the end cap. In the motion guide device,
A fitting recess extending along at least a part of the oil passage forming position is formed on a surface of the end cap facing the slider body, and is fitted into the fitting recess and has the same material hardness as the end cap. Or a low separate member, an oil passage groove is formed in at least one of the joint surfaces of the fitting recess and the separate member facing each other, and the oil passage groove is formed on at least one of the opposed joint surfaces. A linear motion guide device comprising one or two or more projections extending along an oil passage groove. 2. The linear motion guide device according to claim 1, wherein the depth of the fitting recess is equal to or substantially equal to the thickness of the separate member in the fitting direction. The direction change path of the end cap is a linear motion guide device formed by fitting a return guide into a direction change path forming groove formed in the end cap, wherein the separate member and the return guide are integrally formed. The linear motion guide device according to claim 1, wherein the linear motion guide device is provided. The lubricant according to any one of claims 1 to 3, wherein the lubricant is lubricating oil, and a lubricant holding member is inserted in a part of an oil passage formed in the end cap. Linear motion guide device.

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