JP2009138945A - Bush bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bush bearing which keeps the roundness of an inner circumference surface after press fitting, while press fitted easily without crushing an opening end of a hole to press fit in without producing metal powder etc. when press fitted in the hole of a housing. <P>SOLUTION: A bush bearing 1 is provided with: an inner circumference surface 2 of a cylindrically shaped as a slide way; and an outer peripheral surface 3, both of which are abutted to each other at an abutting surface 4 to form a wrapping bushing bearing. The outer peripheral surface 3, is provided with: a cylindrical surface 11; a tapered surface 13 roll-formed and interposed between the cylindrical surface 11 and an end surface 12 in the axial direction X; a smooth circular arc surface interposed between the tapered surface 13 and the cylindrical surface 11; and a smooth circular arc surface interposed between the tapered surface 13 and the end surface 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bush bearing for rotatably supporting a shaft, and more particularly to a bush bearing that is fixed to a housing on an outer peripheral surface and rotatably supports the shaft on an inner peripheral surface.

  Bush bearings as slide bearings have the advantage of being low in price and generating less noise and being excellent in low sound performance compared to rolling bearings. It is used in many fields.

  The bush bearing is usually press-fitted into a hole in the housing and fixed to the housing at the outer peripheral surface thereof, and the shaft is rotatably supported at the inner peripheral surface. In order to facilitate, a tapered surface is formed on the outer peripheral surface on the end surface side of the bush bearing.

  By the way, in order to form such a tapered surface, if a cutting tool (bite) is simply applied to the outer peripheral surface on the end surface side of the bush bearing and scraped off, minute burrs are generated on the outer peripheral surface. Drops when the bushing is pressed into the housing hole, and remains in the housing hole as scrap (for example, metal dust). The scrap enters between the inner peripheral surface of the bush bearing and the shaft. There is a risk that smooth shaft rotation cannot be secured. In particular, in the case of an aluminum housing, when the bush bearing is press-fitted into the hole of the bush bearing, the inner peripheral surface of the housing defining the hole is shaved by a burr to produce aluminum chips, and the aluminum cutting powder is generated by the bush bearing. There is also a possibility that the smooth shaft rotation cannot be secured due to intrusion between the inner peripheral surface of the shaft and the shaft.

  Furthermore, when the thickness of the end surface side of the bush bearing becomes extremely thin with the formed tapered surface, the end surface side of the bush bearing is easily deformed by press-fitting into the hole of the housing, and the inner peripheral surface of the bush bearing is In order to avoid the circularity being guaranteed, if the tapered surface is formed so that the thickness of the end surface side of the bush bearing is increased, the bush bearing is aligned with the hole of the housing before press-fitting into the hole of the housing. In addition to being difficult to fix, there is almost no guide action due to the tapered surface in the press-fitting into the hole of the housing, and the end surface side of the bush bearing is crushed or the opening end of the hole of the housing is unnecessarily enlarged. There is a fear.

  The present invention has been made in view of the above-mentioned points, and the object of the present invention is that there is no generation of debris (for example, metal debris, particularly aluminum chips) upon press-fitting into the hole of the housing. It is an object of the present invention to provide a bush bearing that can be easily press-fitted without crushing the opening end or the like of the hole to be formed and that can ensure the roundness of the inner peripheral surface even after the press-fitting.

  The bush bearing according to the first aspect of the present invention is a cylindrical bush bearing having an inner peripheral surface which is a sliding surface. Here, the outer peripheral surface of the bush bearing includes a cylindrical surface, and the cylindrical surface and the bush. And a taper surface formed by press molding and interposed between at least one annular end surface in the axial direction of the bearing, and has a radius r1 on the cylindrical surface of the bush bearing and one annular end surface. The difference δ (= r1−r2) with the radius r2 of the outer peripheral edge is in the range of 0.1 t or more and 0.3 t or less, where t is the thickness of the bushing bearing on the cylindrical surface.

  According to the bush bearing of the first aspect, since the taper surface is formed by press molding, no burr is generated on the outer peripheral surface, and therefore, even when press-fitted into the hole of the housing (for example, metal dust, particularly (Aluminum chips) is not generated, and the difference δ is 0.1 t or more. As a result, it is possible to secure the outer peripheral edge of the annular end surface having a small diameter with respect to the hole diameter of the housing. The positioning with respect to the hole of the housing can be surely performed, the guiding action by the tapered surface can be secured in the press-fitting into the hole of the housing, and the difference δ is 0.3 t or less. As a result, it is possible to secure the degree of roundness of the inner peripheral surface even after press-fitting.

  In the bush bearing of the present invention, the thickness t is not particularly limited, but a preferable example is a thickness t of 0.5 mm to 5.0 mm, and a more preferable example is a thickness t of 1.0 mm to 3.0 mm. t.

  According to the bush bearing of the second aspect of the present invention, in the bush bearing of the first aspect, the tapered surface extends in the axial direction continuously from one annular end surface, and the cylindrical surface continues from the tapered surface. It extends in the axial direction toward the other end surface in the axial direction of the bush bearing.

  The bush bearing of the present invention may be an endless cylindrical one (a bush bearing without a butt surface), but preferably the bush bearing has a sliding surface on one surface as in the third aspect thereof. The plate is composed of a wound bush bearing wound in a cylindrical shape with the sliding surface positioned on the inner peripheral side.

  According to the bush bearing of the fourth aspect of the present invention, in the bush bearing of the third aspect, the plate is integrally attached to the back metal coated with copper and the copper coating layer on one surface of the back metal. Porous sintered metal layer, and synthetic resin impregnated in the porous sintered metal layer and partially formed on one surface of the porous sintered metal layer and having self-lubricity and wear resistance The wound bush bearing is formed by winding the multilayer plate in a cylindrical shape so that the sliding layer is positioned on the inner peripheral side.

  The thickness of the copper coating layer covering the back metal is preferably 1 μm to 10 μm, more preferably 3 μm to 5 μm, and such a coating layer may be formed by a plating process on the back metal.

  As a steel plate used for the back metal, a cold rolled steel plate (SPCC: JISG4141) having a plate thickness of 0.3 mm to 3.0 mm, preferably 0.6 mm to 1.8 mm, a general structural rolled steel plate (SS: JISG3101), etc. Can be used.

  As the metal powder for forming the porous sintered metal layer, a copper alloy powder that passes through approximately 100 mesh, such as the metal itself, bronze, lead bronze or phosphor bronze excellent in frictional wear characteristics is used. Depending on the case, powders other than copper alloys, such as aluminum alloys and iron, can be used, and the metal powder particles can be in the form of lumps, spheres or irregular shapes. The thickness is preferably about 0.15 to 0.4 mm, and more preferably 0.2 to 0.3 mm, and the porosity is preferably about 10% by volume or more, especially 15 to 40% by volume. .

  Synthetic resin with self-lubricating and wear resistance as a material for forming the sliding layer contains polytetrafluoroethylene resin, polytetrafluoroethylene resin containing polytetrafluoroethylene resin, lead or polyimide resin, polyacetal resin or lubricant. An oil-containing polyacetal resin to be used can be mentioned as a preferred example.

  According to the bush bearing of the fifth aspect of the present invention, in the bush bearing of the fourth aspect, the tapered surface is an exposed surface of the copper coating layer.

  In the bush bearing according to the sixth aspect of the present invention, in the bush bearing according to any one of the first to fifth aspects, the tapered surface is flat or convex outward, and the cylindrical surface and one annular end surface Extends in the axial direction.

  In the bush bearing of the seventh aspect of the present invention, in the bush bearing of any one of the first to sixth aspects, a smooth arc surface is interposed between the tapered surface and the cylindrical surface. The smooth arc surface preferably has a radius of curvature of 0.1 mm or more and 1.0 mm or less, like the bush bearing of the eighth aspect of the present invention.

  In the bush bearing of the ninth aspect of the present invention, in the bush bearing of any one of the first to eighth aspects, a smooth arc surface is interposed between the tapered surface and one annular end surface. Such a smooth arc surface preferably has a radius of curvature of 0.1 mm or more and 0.5 mm or less, like the bush bearing of the tenth aspect of the present invention.

  In the bush bearing according to the eleventh aspect of the present invention, in the bush bearing according to any one of the first to tenth aspects, the crossing angle θ between the tapered surface and the axial center line is not less than 15 ° and not more than 25 °. It is.

  The tapered surface in the present invention is formed by press molding as described above. In the press molding, it is preferably formed by roll molding like the bush bearing of the twelfth aspect of the present invention. is there.

  In the present invention, the outer peripheral surface of the bush bearing only needs to have a tapered surface interposed between the cylindrical surface and at least one annular end surface in the axial direction of the bush bearing. In addition to such a tapered surface, the bush bearing according to the thirteenth aspect of the present invention further includes another tapered surface interposed between the cylindrical surface and the other annular end surface in the axial direction of the bush bearing. ing.

  The other tapered surface may be configured in the same manner as the tapered surface described above, like the bush bearing according to the fourteenth to twenty-second aspects of the present invention.

  According to the present invention, there is no generation of dust (for example, metal dust, especially aluminum chips) when press-fitting into the hole of the housing, and press-fitting can be easily performed without crushing the opening end of the hole to be press-fitted. In addition, it is possible to provide a bush bearing that can ensure the roundness of the inner peripheral surface even after press-fitting.

It is a perspective view of an example of a desirable embodiment of the present invention. It is sectional drawing of the example shown in FIG. It is a partially expanded cross-sectional explanatory drawing of the example shown in FIG. It is explanatory drawing of the manufacturing method of the example shown in FIG. It is explanatory drawing of the manufacturing method of the example shown in FIG. It is explanatory drawing of the usage example of the example shown in FIG.

  Next, the present invention and its embodiments will be described in more detail with reference to preferred examples shown in the drawings. The present invention is not limited to this example.

  1 to 3, the cylindrical bush bearing 1 of the present example includes a cylindrical inner peripheral surface 2 that is a sliding surface and an outer peripheral surface 3, which are abutted against each other at a butting surface 4. It consists of a wound bush bearing.

  The outer peripheral surface 3 is interposed between the cylindrical surface 11 and the cylindrical surface 11 and one annular end surface 12 in the axial direction X, and is formed by press forming, in this example, by roll forming of press forming. Tapered surface 13, smooth arc surface 14 interposed between taper surface 13 and cylindrical surface 11, smooth arc surface 15 interposed between taper surface 13 and end surface 12, cylindrical surface 11 and shaft Between the other annular end surface 16 in the direction X and by press molding, in this example, the taper surface 17 formed by roll molding of press molding, and the taper surface 17 and the cylindrical surface 11 A smooth arc surface 18 interposed therebetween and a smooth arc surface 19 interposed between the tapered surface 17 and the end surface 16 are provided.

  Since each of the taper surface 17, the arc surface 18 and the arc surface 19 is configured in the same manner as the taper surface 13, the arc surface 14 and the arc surface 15, hereinafter, the taper surface 13, the arc surface 14 and the arc surface 15 will be described. The side will be described in detail, and the description of the tapered surface 17, the arc surface 18 and the arc surface 19 side will be omitted.

  The tapered surface 13 that is inclined and extends in the axial direction X between the cylindrical surface 11 and the end surface 12 and that is an exposed surface of the copper coating layer 31 is flat or convex outward with a radius of curvature R1. The cylindrical surface 11 continuously extends from the end surface 12 via the arc surface 15 in the axial direction X, and the cylindrical surface 11 extends from the tapered surface 13 via the arc surface 14 in the axial direction X and the end surface 16 in the axial direction X. And parallel to the axial direction X.

  A smooth circular arc surface 14 interposed between the tapered surface 13 and the cylindrical surface 11 has a radius of curvature R2 of 0.1 mm or more and 1.0 mm or less. The smooth circular arc surface 15 interposed between them has a radius of curvature R3 of 0.1 mm or more and 0.5 mm or less, and the intersection angle θ between the tapered surface 13 and the axis 20 is It is 15 ° or more and 25 ° or less.

  The difference δ (= r1-r2) between the radius r1 of the cylindrical surface 11 of the bush bearing 1 and the radius r2 of the outer peripheral edge 32 of the end surface 12 is 0 when the thickness of the cylindrical surface 11 of the bush bearing 1 is t. .1t or more and 0.3t or less.

  The bush bearing 1 may be manufactured as follows. That is, a press roller 52 having a cylindrical surface 51 as shown in FIGS. 4 and 5 and a press roller 54 having an annular recess surface 53 complementary to the outer peripheral surface 3 are prepared. A back metal 61 covered with copper serving as the coating layer 31 and a copper coating layer on one surface 62 of the back metal 61 in a space 55 formed by the cylindrical surface 51 of 52 and the annular recess surface 53 of the press roller 54. A porous sintered metal layer 63 integrally attached to 31, a porous sintered metal layer 63 impregnated in the porous sintered metal layer 63 and partly formed on one surface of the porous sintered metal layer 63 and self-lubricating A strip-shaped plate 65 made of a multilayer plate having a sliding layer 64 containing a synthetic resin having heat resistance and wear resistance is inserted, and the plate 65 is roll-formed by press rollers 52 and 54 that rotate. The tapered surfaces 13 and 17 and the arcuate surfaces 14 and 15 A surface corresponding to 18 and 19 is formed on one surface 66 of the plate 65, and then has a sliding surface 67 composed of such a multilayer plate and an exposed surface of the sliding layer 64 on one surface, while the other surface A plate 65 having a surface 66 formed of the exposed surface of the coating layer 31 is cut to an appropriate length to form a strip-shaped plate 65, and the strip-shaped plate 65 obtained in this way has a sliding surface 67 inside. It winds cylindrically so that it may be located in the circumference side, and after this winding, upset is performed as needed and the cylindrical shape is adjusted, and the winding bush bearing 1 shown in FIGS. 1-3 is obtained.

  According to the bush bearing 1, since the taper surface 13 is formed by roll forming, no burr is generated on the outer peripheral surface 3. As a result, the hole 72 of the aluminum housing 71 of the compressor of an automobile as shown in FIG. In addition, there is no generation of copper dust in the coating layer 31 due to burrs during press-fitting into the housing, and the inner peripheral surface 73 of the housing 71 that defines the holes 72 can be shaved with burrs, so there is no generation of aluminum chips. In addition, since the difference δ is 0.1 t or more, the outer peripheral edge 32 of the annular end surface 12 having a small diameter (= 2 · r2) with respect to the hole diameter r3 of the housing 71 can be secured. The positioning with respect to the hole 72 of the housing 71 before press-fitting can be reliably performed, and the guide action by the tapered surface 13 can be secured in press-fitting into the hole 72 of the housing 71. Since δ is 0.3 t or less, the wall thickness (radial width) of the end surface 12 can be ensured to such an extent that deformation on the end surface 12 side does not occur in press-fitting into the hole 72 of the housing 71. The roundness of the surface 2 can be guaranteed even after press-fitting with a tightening margin.

DESCRIPTION OF SYMBOLS 1 Bush bearing 2 Inner peripheral surface 3 Outer peripheral surface 11 Cylindrical surface 12 End surface 13 Tapered surface

Claims (22)

  A cylindrical bush bearing having an inner peripheral surface that is a sliding surface, and the outer peripheral surface of the bush bearing is between the cylindrical surface and at least one annular end surface in the axial direction of the bush bearing. And a taper surface formed by press molding, and a difference δ (= r1−r2) between a radius r1 of the cylindrical surface of the bush bearing and a radius r2 of the outer peripheral edge of one annular end surface ) Is a bush bearing in the range of 0.1 t or more and 0.3 t or less, where t is the thickness of the cylindrical surface of the bush bearing.   The tapered surface continuously extends in the axial direction from one annular end surface, and the cylindrical surface continuously extends from the tapered surface in the axial direction toward the other end surface in the axial direction of the bush bearing. The bush bearing according to claim 1.   3. The bush bearing according to claim 1, wherein the bush bearing is formed by winding a plate having a sliding surface on one surface into a cylindrical shape so that the sliding surface is located on the inner peripheral side. Consists of.   The plate comprises a back metal coated with copper, a porous sintered metal layer integrally attached to a copper coating layer on one side of the back metal, and a part of the porous sintered metal layer impregnated and Is formed on one surface of a porous sintered metal layer and has a sliding layer including a synthetic resin having a self-lubricating property and wear resistance. The bush bearing according to claim 3, wherein the layer plate is wound in a cylindrical shape so that the sliding layer is located on the inner peripheral side.   The bush bearing according to claim 4, wherein the tapered surface is an exposed surface of a copper coating layer.   The bush bearing according to any one of claims 1 to 5, wherein the tapered surface extends in the axial direction between the cylindrical surface and the one annular end surface so as to be flat or convex outward.   The bush bearing according to any one of claims 1 to 6, wherein a smooth arc surface is interposed between the tapered surface and the cylindrical surface.   The bush bearing according to claim 7, wherein the smooth arc surface interposed between the tapered surface and the cylindrical surface has a radius of curvature of 0.1 mm or more and 1.0 mm or less.   The bush bearing according to any one of claims 1 to 8, wherein a smooth arc surface is interposed between the tapered surface and one annular end surface.   The bush bearing according to claim 9, wherein the smooth arc surface interposed between the tapered surface and the one annular end surface has a radius of curvature of 0.1 mm or more and 0.5 mm or less.   11. The bushing bearing according to claim 1, wherein an intersection angle θ between the tapered surface and the shaft center line is not less than 15 ° and not more than 25 °.   The bush bearing according to any one of claims 1 to 11, wherein the tapered surface is formed by roll forming.   In addition to the tapered surface interposed between the cylindrical surface and one annular end surface, the outer peripheral surface of the bush bearing is interposed between the cylindrical surface and the other annular end surface in the axial direction of the bush bearing. The bush bearing according to any one of claims 1 to 12, further comprising another tapered surface formed by press molding.   The other tapered surface continuously extends in the axial direction from the other annular end surface, and the cylindrical surface continuously extends from the other tapered surface toward one end surface in the axial direction of the bush bearing. The bushing bearing according to claim 13 extending.   The bush bearing according to claim 13 or 14, wherein the other tapered surface extends in the axial direction between the cylindrical surface and the other annular end surface so as to be flat or convex outward.   The bush bearing according to any one of claims 13 to 15, wherein a smooth arc surface is interposed between the other tapered surface and the cylindrical surface.   The bushing bearing according to claim 16, wherein the smooth arc surface interposed between the other tapered surface and the cylindrical surface has a radius of curvature of 0.1 mm or more and 1.0 mm or less.   The bush bearing according to any one of claims 13 to 17, wherein a smooth arc surface is interposed between the other tapered surface and the other annular end surface.   The bush according to claim 18, wherein the smooth arc surface interposed between the other tapered surface and the other annular end surface has a radius of curvature of 0.1 mm or more and 0.5 mm or less. bearing.   The bush bearing according to any one of claims 13 to 19, wherein an intersection angle θ between the other tapered surface and the axial center line is not less than 15 ° and not more than 25 °.   The bushing bearing according to any one of claims 13 to 20, wherein the other tapered surface is formed by roll forming.   The bush bearing according to any one of claims 13 to 21, wherein the bush bearing is the wound bush bearing according to claim 3, and the plate is a multilayer plate according to claim 4. In the bearing, the other tapered surface is an exposed surface of the copper coating layer.

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