JP2014040869A - Thrust slide bearing made of synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust slide bearing made of synthetic resin, capable of increasing a decrease amount of a volume of filled fluid to cause the fluid to generate a larger pressure and thus reducing a slide friction resistance.SOLUTION: A thrust slide bearing 1 includes an upper case 2 made of synthetic resin, a lower case 41 made of synthetic resin, and a thrust slide bearing piece 71 made of synthetic resin and provided between the upper case 2 and the lower case 41. An upper annular face 75 of the thrust slide bearing piece 71 has a center annular concave surface 87. An annular concave portion 84 serves as a stagnation part for lubricant such as grease.

Description

  The present invention relates to a thrust slide bearing made of synthetic resin, and more particularly to a thrust slide bearing made of synthetic resin which is preferably incorporated as a thrust slide bearing of a strut type suspension (McPherson type) in a four-wheeled vehicle.

  In general, a strut suspension is mainly used for a front wheel of a four-wheeled vehicle, and is a combination of a suspension coil spring and a strut assembly in which a hydraulic shock absorber is incorporated in an outer cylinder integrated with a main shaft. Such a suspension has a structure in which the axis of the coil spring is positively offset with respect to the axis of the strut to smoothly slide the piston rod of the shock absorber built in the strut, and the axis of the strut. Some coil springs are arranged with their axes aligned. In either structure, a bearing is disposed between the mounting member of the vehicle body and the upper spring seat of the coil spring to smoothly allow the rotation when the strut assembly rotates together with the coil spring by the steering operation. Yes.

  As this bearing, a rolling bearing using a ball or a needle or a synthetic resin sliding bearing is used. However, the rolling bearing has a problem that it may be difficult to maintain a smooth steering operation because the ball or needle may be damaged due to a minute swing and vibration load. The sliding bearing made of synthetic resin has a problem that the friction torque is higher than that of the rolling bearing and the steering operation becomes heavy. Furthermore, in any of the bearings, there is a problem that the steering operation becomes heavy due to the high sliding frictional force of the dust seal made of a rubber elastic body that is mounted to prevent foreign matter such as dust from entering the sliding surface. A synthetic resin sliding bearing has a problem of making the steering operation heavier.

To solve the above problem, for example, one annular groove and a plurality of dead-end radiation grooves communicating with the annular groove are formed on the sliding surface of the synthetic resin bearing piece disposed in the upper and lower cases. Or an inner annular groove, an outer annular groove formed radially spaced from the inner annular groove, and a plurality of radiating grooves communicating with the inner and outer annular grooves to form an actual slide of the bearing piece. A method of reducing the sliding surface, in other words, increasing the load per unit area (surface pressure: kgf / cm ² ) to reduce the sliding frictional resistance; By forming on a textured surface by a textured process consisting of a large number of convex portions scattered in a regular shape or an indeterminate shape divided into the concave portions, and improving the retention of a lubricant such as grease on the textured surface, the above In addition to reducing sliding friction resistance, reducing sliding friction resistance And a method (Patent Document 1).

Microfilm of Japanese Utility Model No. 63-37230 (Japanese Utility Model Application No. 1-1141926)

  By the way, with respect to the above problems, for example, an upper annular body having an annular surface and the upper annular body are overlaid so as to be rotatable around the axis of the upper annular body. A lower annular body having an annular surface facing the annular surface of the upper annular body, and the annular surface of either one of the annular bodies is provided with the other annular body. A closed recess surrounded by a synthetic resin projection having a flat tip surface slidably contacting the annular surface is formed, and the closed recess is filled with fluid (grease), The sliding surface of the other annular body with respect to the annular surface of one annular body is composed of the tip of the protrusion that contacts the annular surface of the one annular body and the surface of the fluid filled in the closed recess, and is subjected to a thrust load. Therefore, the flow of the closed recess is caused by the bending deformation of the protrusion formed on the annular surface of one annular body. A synthetic resin thrust sliding bearing that reduces sliding frictional resistance by reducing the filling volume and generating pressure on the fluid in the closed recess is conceivable. Even in the case of a sliding bearing, in order to further reduce the sliding frictional resistance, it is desired to increase the amount of decrease in the fluid filling volume to generate a large pressure in the fluid.

  The present invention has been made in view of the above-mentioned points, and an object of the present invention is to increase the amount of decrease in the fluid filling volume and generate a large pressure in the fluid, thereby reducing the sliding frictional resistance. It is an object to provide a thrust sliding bearing made of synthetic resin.

  The synthetic resin thrust slide bearing of the present invention is overlaid with a synthetic resin upper case having an upper annular plane, and the upper case so as to be rotatable about the axis of the upper case. A lower annular plane facing the upper annular plane of the upper case, first and second annular projections and first and second annular projections formed concentrically with each other on the lower annular plane; A lower case made of a synthetic resin, each having an enclosed wide lower annular recess, an upper annular surface slidably contacting the upper annular plane, a lower annular surface slidably contacting the lower annular plane, and an upper circle Inner frustoconical surface and upper annular surface having a reduced diameter from the upper annular edge connected to the inner upper annular edge of the annular surface to the lower annular edge connected to the inner lower annular edge of the lower annular surface The lower annular surface from the upper annular edge connected to the outer upper annular edge of A synthetic resin thrust sliding bearing having outer frusto-conical surfaces that are expanded toward the lower annular edge connected to the outer lower annular edge and arranged in the lower annular recess of the lower case The upper annular surface of the thrust slide bearing piece is concentrically arranged with a central annular concave surface defining an annular concave portion filled with a lubricant and the central annular concave surface interposed therebetween. And an inner upper annular projecting surface and an outer upper annular projecting surface slidably contacting the upper annular plane, and the lower annular surface of the thrust slide bearing piece is below the lower case The annular recess has a lower annular projection surface slidably contacting the lower annular plane of the lower case.

  According to the thrust sliding bearing made of the synthetic resin of the present invention, the lower annular projecting surface of the thrust sliding bearing piece slidably contacting the lower annular plane of the lower case under a thrust load is used as a fulcrum. The thrust sliding bearing piece mainly causes bending deformation in the central annular concave surface to reduce the volume of the annular concave portion and to generate internal pressure in the lubricant filled in the annular concave portion. Since the thrust load is supported by the inner annular projecting surface, the outer annular projecting surface, and the lubricant surface with respect to the relative rotation between the case and the lower case, the relative rotation can be performed with extremely low sliding friction resistance. Even if a bending deformation occurs in the thrust slide bearing piece, the thrust slide bearing piece is connected from the upper annular edge connected to the inner upper annular edge of the upper annular surface to the inner lower annular edge of the lower annular surface. The diameter expands from the upper annular edge connected to the outer upper annular edge of the upper annular surface to the lower annular edge connected to the outer lower annular edge of the lower annular surface. And the outer frusto-conical surface is the outer peripheral surface of the first annular protrusion of the lower case, and the outer frusto-conical surface is the inner peripheral surface of the second annular protrusion. They do not interfere with each other, and do not hinder reduction of sliding frictional resistance due to interference during relative rotation.

  In the thrust slide bearing made of synthetic resin of the present invention, the central annular concave surface is connected to the outer bottom edge of the inner upper annular projecting surface from the outer bottom edge connected to the inner bottom edge of the annular bottom surface. The diameter is increased from the inner annular side surface that is expanded to the inner annular edge and from the inner annular edge that is connected to the outer peripheral edge of the annular bottom surface to the outer annular edge that is connected to the inner annular edge of the outer upper annular projecting surface. And an outer annular side surface. In such a case, the volume of the annular recess can be increased, and the amount of lubricant filled can be increased.

  In the thrust sliding bearing made of the synthetic resin of the present invention, the lower annular projecting surface may be arranged to face the annular bottom surface of the central annular concave surface in the axial direction. In such a case, bending deformation under a thrust load can be easily generated, and the volume of the annular recess can be reduced, and as a result, a large internal pressure can be generated in the lubricant filled in the annular recess.

  In the thrust slide bearing made of the synthetic resin of the present invention, the central annular concave surface may be a curved concave surface.

  In the thrust sliding bearing made of the synthetic resin of the present invention, each of the inner upper annular projecting surface and the outer upper annular projecting surface may be a curved convex surface. In such a case, it is possible to increase the surface pressure (load per unit area) by using a curved convex surface, whereby the upper annular plane, the inner upper annular projecting surface, and the outer upper annular projecting surface of the upper case. The sliding frictional resistance with each of the curved convex surfaces can be reduced.

  In the thrust slide bearing made of the synthetic resin of the present invention, the lower annular surface of the thrust slide bearing piece includes an inner lower annular concave surface connected to an inner peripheral edge of the lower annular projection surface by an outer annular edge, and a lower annular surface. An outer lower annular concave surface connected to the outer peripheral edge of the projecting surface by an inner annular edge; an inner lower annular convex surface connected to the inner annular edge of the inner lower annular concave surface and the lower annular edge of the inner frustoconical surface; The outer lower annular concave surface may have an outer annular edge and an outer lower annular projecting surface connected to the lower annular edge of the outer frustoconical surface. In such a case, bending deformation under a thrust load can be easily generated, and the volume of the annular recess can be reduced, and as a result, a large internal pressure can be generated in the lubricant filled in the annular recess.

  In the thrust slide bearing made of the synthetic resin of the present invention, the lower annular projecting surface may protrude below the inner lower annular projecting surface and the outer lower annular projecting surface.

  In the thrust slide bearing made of the synthetic resin of the present invention, each of the inner lower annular concave surface and the outer lower annular concave surface may be a curved concave surface.

  In the thrust sliding bearing made of the synthetic resin of the present invention, each of the inner lower annular projecting surface and the outer lower annular projecting surface may be a curved convex surface.

  In the synthetic resin thrust sliding bearing of the present invention, the lower annular projecting surface may be a curved convex surface.

  In the synthetic resin thrust slide bearing of the present invention, the upper case has an upper annular plane having an upper annular plane on the lower surface and a circular hole in the center, and an outer peripheral edge of the upper annular portion. A cylindrical engagement drooping portion formed integrally with an annular engagement portion formed on the inner peripheral surface of the cylindrical engagement drooping portion. A lower annular portion having a flat surface and having an insertion hole concentric with the circular hole at the center is provided, and the first annular protrusion is formed integrally with the lower annular portion. The second annular protrusion is integrally formed on the outer peripheral edge of the lower annular part at a predetermined interval radially outward with respect to the first annular protrusion, The lower annular recess is defined by the outer circumferential surface of the first annular projection, the inner circumferential surface of the second annular projection, and the lower annular plane. The upper case further includes an annular engagement portion formed on the outer peripheral surface of the annular protrusion, and the upper case elastically attaches the annular engagement portion to the annular engagement portion of the lower case. It may be combined with a case. In such a case, the upper and lower cases are combined with each other by elastically attaching the annular engagement portion of the upper case to the annular engagement portion of the lower case, so that the workability is good and the assembly is extremely easy. Can be done.

  In the thrust slide bearing made of the synthetic resin of the present invention, the upper case is spaced radially outward from the peripheral edge of the circular hole in the central portion of the upper annular portion and is against the inner peripheral surface of the cylindrical engagement hanging portion. A first outer annular groove is formed integrally with the upper annular portion at a predetermined interval radially inward and cooperates with the inner peripheral surface of the cylindrical engagement hanging portion on the outer peripheral surface. The lower case is integrally formed with the lower annular portion at a predetermined interval radially outward with respect to the outer peripheral surface of the first annular protrusion. And a third annular protrusion that forms a lower outer annular groove in cooperation with the inner peripheral surface of the second annular protrusion on the outer peripheral surface, and the upper case is connected to the upper outer annular groove. While the second annular protrusion is arranged, the first cylindrical hanging part is arranged in the lower outer annular groove so that the second and third annular protrusions are radially arranged. By tatami mats, it may have been been combined to lower case. According to such a thrust slide bearing, the upper case has the second annular protrusion disposed in the upper outer annular groove, while the first cylindrical hanging portion is disposed in the lower outer annular groove. Since the annular engaging portions are overlapped in the radial direction and elastically attached to the annular protrusions and combined with the lower case, the diameters of the first cylindrical hanging portion and the second and third annular protrusions As a result of the formation of the sealing portion by the labyrinth action in the elastic mounting portion between the direction overlapping portion and the engaging portion, entry of foreign matters such as dust into the thrust sliding bearing surface between the upper and lower cases is effectively prevented.

  In the thrust sliding bearing made of the synthetic resin of the present invention, the upper annular portion is integrally formed with a predetermined interval radially inward with respect to the inner peripheral surface of the first cylindrical hanging portion. It further comprises a second cylindrical hanging portion that forms a wide upper annular recess in cooperation with the inner peripheral surface and the upper annular portion, and the first annular protrusion has an annular shoulder portion in the insertion hole. The upper case has a lower end surface of the second cylindrical hanging portion facing the upper surface of the annular shoulder portion with a gap and a second cylindrical hanging portion that is a first annular protrusion. It may be combined with the lower case so as to overlap in the radial direction. According to such a thrust slide bearing, the upper case has the second cylindrical hanging portion arranged in the radial direction with the first annular protrusion of the lower case, and the first cylindrical hanging portion is arranged in the lower outer annular groove. Since the second and third annular protrusions are overlapped with each other in the radial direction, and the annular engagement portions are elastically attached to each other and combined with the lower case, the second cylindrical hanging portion and the first annular protrusion As a result of the formation of the labyrinth-sealed sealing portion in the overlapping portion of the first cylindrical hanging portion and the overlapping portion of the second and third annular protrusions and the elastic mounting portion between the engaging portions, the upper and lower portions Intrusion of foreign matter such as dust into the thrust sliding bearing surface between the cases is further prevented. The second cylindrical hanging portion may have an inner peripheral surface having the same diameter as the circular hole in the central portion of the upper annular portion, and an annular shoulder portion is provided in the circular hole in the central portion of the upper annular portion. It may be adjacent to the outside in the radial direction.

  In the thrust slide bearing made of the synthetic resin of the present invention, the lower case has the first annular protrusion so as to form the lower inner annular groove in cooperation with the inner peripheral surface of the first annular protrusion on the outer peripheral surface. A fourth annular protrusion formed integrally on the upper surface of the annular shoulder portion of the lower annular portion with a predetermined interval radially inward, and the upper case includes The two cylindrical hanging portions may be arranged in the lower inner annular groove and overlapped with the first annular protrusion and the fourth annular protrusion in the radial direction and combined with the lower case. According to such a thrust slide bearing, the upper case has a second cylindrical hanging portion arranged in the lower inner annular groove, and is superposed in the radial direction on the first annular protrusion and the fourth annular protrusion. As a result of the further formation of a sealing portion by labyrinth action in the radial overlapping portion of the second cylindrical hanging portion and the first and fourth annular protrusions, the upper and lower cases, in particular, Intrusion of foreign matters such as dust from the inner peripheral surface side to the thrust sliding bearing surface is further prevented. The fourth annular protrusion may have an inner peripheral surface having the same diameter as the insertion hole formed in the central part of the lower annular part, and the insertion hole in the central part of the lower annular part It may be formed integrally with the upper surface of the annular shoulder portion of the lower annular portion so as to be radially outward from the outer circumferential portion.

  In the thrust slide bearing made of the synthetic resin of the present invention, the upper case is formed at the center of the upper annular portion so as to form an upper inner annular groove in cooperation with the inner peripheral surface of the second cylindrical hanging portion on the outer peripheral surface. And a third cylindrical hanging portion integrally formed on the lower surface of the annular shoulder portion of the upper annular portion with an inner peripheral surface having the same diameter as that of the circular hole of the upper portion. The end surface is opposed to the upper surface of the annular shoulder portion of the lower annular portion with a gap, and the third cylindrical hanging portion is radially overlapped with the fourth annular projection, and the fourth annular projection is formed in the upper inner annular groove. May be combined with the lower case. According to such a thrust slide bearing, the upper case has the third cylindrical hanging portion overlapped with the fourth annular protrusion in the radial direction, the fourth annular protrusion is disposed in the upper inner annular groove, Since the two cylindrical hanging parts are arranged in the lower inner annular groove and overlapped with the first annular protrusion and the fourth annular protrusion in the radial direction, respectively, and combined with the lower case, the second and third As a result of a labyrinth-sealed sealing portion formed in the radial overlap of the cylindrical hanging portion and the first annular protrusion and the fourth annular protrusion, a thrust is formed between the upper and lower cases, particularly from the inner peripheral surface side. Intrusion of foreign matter such as dust into the sliding bearing surface is further prevented.

  In the thrust slide bearing made of the synthetic resin of the present invention, the lower case has a cylindrical portion formed integrally with the lower annular portion having an inner peripheral surface having the same diameter as the insertion hole in the central portion. May be. According to such a thrust sliding bearing, the mounting operation can be performed very simply by inserting the cylindrical portion into the mounting hole formed in the mounting member of the thrust sliding bearing.

  In the thrust sliding bearing made of the synthetic resin of the present invention, the upper case has a cylindrical portion integrally formed on the upper annular portion with an inner peripheral surface having the same diameter as the inner diameter of the circular hole in the central portion of the upper annular portion. Further, the outer peripheral surface of the cylindrical portion may be slidably contacted with the inner peripheral surface of the cylindrical portion of the lower case, and may be combined with the lower case. According to such a thrust sliding bearing, in addition to allowing smooth sliding under a thrust load, a radial formed between the outer peripheral surface of the cylindrical portion of the upper case and the inner peripheral surface of the cylindrical portion of the lower case By sliding between the synthetic resins in the bearing portion, sliding under a radial load can be smoothly allowed.

  In the thrust slide bearing made of the synthetic resin of the present invention, the upper annular portion is formed from a circular belt-like plane having a predetermined width radially outward from the outer peripheral edge of the central hole and the outer peripheral edge of the circular belt-like plane. You may comprise the annular | circular shaped upper surface which has the downward cone frusto-conical surface over the cylindrical outer peripheral surface of the cylindrical engagement drooping part.

  In the thrust slide bearing made of the synthetic resin of the present invention, the upper annular portion integrally protrudes upward in the axial direction from a circular belt-like plane having a predetermined width radially outward from the outer peripheral edge of the circular hole in the central portion. It may further comprise a circular belt-like protrusion. According to such a thrust sliding bearing, when a variable load such as an inclination acts on the vehicle body side mounting member, at least an elastic mounting portion of the engaging portion of the cylindrical engaging hanging portion and the engaging portion of the cylindrical engaging protruding portion Interference can be avoided more reliably.

  In the thrust slide bearing made of the synthetic resin of the present invention, the upper case, the lower case and the thrust slide bearing piece may be made of a thermoplastic synthetic resin. In such a case, the upper case and the lower case are made of polyacetal resin, It consists of polyamide resin or polyester resin, and the thrust slide bearing piece may consist of polyamide resin, polyolefin resin, or polyester resin.

  According to the present invention, there is provided a thrust sliding bearing made of a synthetic resin capable of generating a large pressure in a fluid such as a lubricant by increasing a decrease amount of a fluid filling volume and reducing sliding frictional resistance. Can do.

FIG. 1 is a cross-sectional view of an example of a preferred embodiment of the present invention. FIG. 2 is a plan view of the thrust bearing piece in the example shown in FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2 of the thrust bearing piece in the example shown in FIG. FIG. 4 is a sectional view of an example of another preferred embodiment of the present invention. FIG. 5 is a cross-sectional view of an example in which the thrust slide bearing of the example shown in FIG. 4 is incorporated in a strut type suspension. FIG. 6 is a cross-sectional view of still another preferred embodiment of the present invention. FIG. 7 is a plan view of the example shown in FIG. FIG. 8 is a cross-sectional view of an example of still another preferred embodiment of the present invention. FIG. 9 is a cross-sectional view of an example of still another preferred embodiment of the present invention. FIG. 10 is a cross-sectional view of an example of still another preferred embodiment of the present invention. FIG. 11 is a cross-sectional view of an example in which the thrust slide bearing shown in FIG. 6 is incorporated in a strut suspension. FIG. 12 is a cross-sectional view of an example of still another preferred embodiment of the present invention.

  Next, the present invention will be described in detail based on an example of a preferred embodiment shown in the drawings. Note that the present invention is not limited to these examples.

  1 to 3, the thrust sliding bearing 1 according to the first embodiment of the present example includes a synthetic resin upper case 2, a synthetic resin lower case 41, and upper and lower cases 2 and 41. A thrust sliding bearing piece 71 made of synthetic resin.

  The upper case 2 includes an upper annular portion 4 having an upper annular plane 5 in contact with the thrust slide bearing piece 71 on the lower surface and a circular hole 3 in the central portion, and an upper annular portion. A cylindrical engagement hanging portion 6 integrally formed on the outer peripheral edge of the upper upper annular plane 5, and an annular engagement portion 8 formed at the end of the inner peripheral surface 7 of the cylindrical engagement hanging portion 6. It has.

  The lower case 41 is superposed on the upper case 2 so as to be rotatable in the circumferential direction R around the axis O of the upper case 2, and the lower case 41 faces the upper annular plane 5 of the upper case 2. A lower annular portion 43 having an annular flat surface 44 on the upper surface and having a concentric insertion hole 42 having the same diameter as the inner diameter of the circular hole 3 of the upper case 2 in the central portion; 42, an annular projection 45 having an inner peripheral surface of the same diameter as that of the lower annular portion 43 and formed integrally with the lower annular plane 44, and radially outward with respect to the annular projection 45. The outer circumferential surface of the lower annular portion 43 is integrally formed on the outer circumferential edge of the lower annular plane 44 at a predetermined interval, concentrically with the annular projection 45, and the outer circumferential surface of the annular projection 45 is formed by the inner circumferential surface 46. An annular protrusion 49 which cooperates with the surface 47 and the lower annular plane 44 to form a wide lower annular recess 48; An annular engagement portion 50 formed on the outer peripheral surface of the lower end of the protrusion 49, and the lower annular recess 48 surrounded by the annular protrusions 45 and 49 is an outer peripheral surface 47 of the annular protrusion 45. And an inner peripheral surface 46 of the annular protrusion 49 and a lower annular plane 44.

  An annular thrust slide bearing piece 71 disposed in the lower annular recess 48 of the lower case 41 is formed by an upper annular surface 75 slidably contacting the upper annular plane 5 and a lower slidable contact with the lower annular plane 44. From the side annular surface 77 and the upper annular edge 121 connected to the inner upper annular edge 76 of the upper annular surface 75 to the lower annular edge 122 connected to the inner lower annular edge 78 of the lower annular surface 77. The inner truncated conical surface 79 having a reduced diameter and the upper annular edge 123 connected to the outer upper annular edge 80 of the upper annular surface 75 are connected to the outer lower annular edge 81 of the lower annular surface 77. And an outer frustoconical surface 82 that expands toward the lower annular edge 124.

  The upper annular surface 75 of the thrust slide bearing piece 71 has an opening 83 at the center in the radial direction X, and is filled with a fluid, for example, a lubricant (not shown) such as grease as a lubricant. A central annular concave surface 87 defining an annular concave portion 84, and a curved convex inner upper annular ring arranged concentrically with the central annular concave surface 87 interposed therebetween and slidably contacting the upper annular plane 5 A projecting surface 90 and an outer upper annular projecting surface 91 are provided.

  The curved concave central annular concave surface 87 includes an annular bottom surface 87a and an inner annular surface connected to the outer annular edge 127 of the inner upper annular projecting surface 90 from the outer annular edge 126 connected to the inner peripheral edge 125 of the annular bottom surface 87a. An inner annular side surface 88 having an inner peripheral frusto-conical surface that is expanded in diameter toward the edge 128, and an inner annular edge 131 of the outer upper annular projecting surface 91 from the inner annular edge 130 that is connected to the outer peripheral edge 129 of the annular bottom surface 87a. And an outer annular side surface 89 having an outer peripheral frusto-conical surface that expands toward the outer annular edge 132 connected to the outer circumferential edge 132.

  The annular recess 84 serves as a reservoir for lubricating oil such as grease. The annular recess 84 is defined by the annular bottom surface 87a, the inner annular side surface 88, and the outer annular side surface 89, whereby the volume of the annular recess 84 is increased. Therefore, the amount of the lubricant filled in the annular recess 84 can be increased.

  The inner annular edge of the inner upper annular projecting surface 90 consists of an inner upper annular edge 76 of the upper annular surface 75, and the outer annular edge of the outer upper annular projecting surface 91 is from the outer upper annular edge 80 of the upper annular surface 75. Become. The inner upper annular projecting surface 90 protrudes upward and defines an annular inner bearing portion 85 that supports the upper annular plane 5, and the outer upper annular projecting surface 91 projects upward and moves upward. An annular outer bearing 86 that supports the annular plane 5 is defined.

  By forming the inner upper annular projecting surface 90 and the outer upper annular projecting surface 91 into an annular curved convex surface, the upper annular plane 5 and the upper annular flat surface 5 form a line contact or a band-shaped contact with a minute width. (Load per area) increases, thereby reducing the sliding frictional resistance between the upper annular flat surface 5 of the upper case 2 and the inner upper annular projecting surface 90 and the outer upper annular projecting surface 91 of the thrust slide bearing piece 71. be able to.

  The thrust slide bearing piece 71 has a curved convex lower annular projecting surface 92 slidably contacting the lower annular plane 44 in the lower annular recess 48 of the lower case 41 and is thrust. The inner side of the curved concave surface connected to the inner peripheral edge 133 of the lower annular projecting surface 92 by the outer annular edge 134 and the lower annular projecting portion 93 projecting downward at the central portion in the radial direction X of the slide bearing piece 71. An annular recess 95 having a lower annular concave surface 94, and an annular concave portion having a curved concave outer lower annular concave surface 98 connected to the outer peripheral edge 135 of the lower annular projecting surface 92 by an inner annular edge 136. 99 and an annular projection 97 having an inner annular edge 137 of the inner lower annular concave surface 94 and a curved convex inner lower annular projection 96 connected to the lower annular edge 122 of the inner frustoconical surface 79; The outer annular edge 1 of the outer lower annular concave surface 98; It has 8 and an annular projection 101 which has an outer outer lower annular protruding surface 100 curved convex articulating the lower annular edge 124 of the frusto-conical surface 82.

  The lower annular surface 77 has the lower annular projecting surface 92, the inner lower annular concave surface 94, the outer lower annular concave surface 98, the inner lower annular projecting surface 96, and the outer lower annular projecting surface 100. The lower annular projecting surface 92 projects below the inner lower annular projecting surface 96 and the outer lower annular projecting surface 100, and is disposed so as to face the annular bottom surface 87a of the central annular concave surface 87 in the axial direction.

  The lower annular projection 93 has a lower annular shape on the inner and outer circumferential sides of the lower annular projection 93 formed at the center in the radial direction X of the lower annular surface 77 of the thrust slide bearing piece 71. By forming annular recesses 95 and 99 connected to the projecting surface 92 and having an inner lower annular concave surface 94 and an outer lower annular concave surface 98, an annular inner bearing portion 85 and an annular outer bearing portion 86 under a thrust load are formed. In addition, the deformation (bending deformation) of the central annular concave surface 87 can be easily performed, and the volume of the annular recess 84 is reduced by the deflection, and thus a large internal pressure is generated in the lubricant filled in the annular recess 84. Line contact or minute contact between the upper annular plane 5 of the upper case 2 and the inner upper annular projecting surface 90 and outer outer annular projecting surface 91 of the annular inner bearing portion 85 and the annular outer bearing portion 86, respectively. What reduction coupled with the sliding friction resistance due to belt contact, it is possible to further reduce the sliding frictional resistance.

  The thrust slide bearing piece 71 has the lower annular projection 93 of the lower annular surface 77 in sliding contact with the lower annular plane 44 that defines the bottom surface 51 of the lower annular recess 48 of the lower case 41, and The annular surface 75 is protruded from the opening 52 of the lower annular recess 48, and the inner upper annular projecting surface 90 and the outer outer annular projecting surface 91 of the annular inner bearing portion 85 and the annular outer bearing portion 86 are arranged on the upper side of the upper case 2. The opening 83 of the annular recess 84 that is brought into contact with the annular plane 5 and filled with a lubricant is closed by the upper annular plane 5 of the upper case 2, and the upper case 2 is connected to the cylindrical engagement hanging portion 6. An annular engagement portion 8 formed on the inner peripheral surface of the end portion of the lower case 41 is elastically attached to an annular engagement portion 50 formed on the outer peripheral surface of the lower end of the annular protrusion 49 of the lower case 41, so that the lower case 41. To make it union.

  According to the thrust slide bearing 1 formed in this way, a lubricating oil such as grease is filled in the annular recess 84 defined by the annular bottom surface 87a, the inner annular side surface 88, and the outer annular side surface 89. At the same time, the annular inner bearing portion 85 and the annular outer bearing portion 86 and / or the central annular concave surface 87 reduce the volume of the annular concave portion 84 and generate an internal pressure in the lubricant filled in the annular concave portion 84 under a thrust load. As a result of bending deformation (bending deformation) and contacting the upper annular plane 5 of the upper case 2, the lubricating oil filled in the annular recess 84 can also share and accept the thrust load, in other words, An annular inner bearing of the thrust sliding bearing piece 71 where the sliding surface of the thrust sliding bearing piece 71 with respect to the upper annular plane 5 of the case 2 contacts the upper annular plane 5 of the upper case 2 It will be formed by the 85 and the inner upper annular protruding surface 90 and outer upper annular protruding surface 91 and fills the annular recess 84 faces the lubrication oil in contact with the upper annular planar fifth annular outer bearing 86.

  Further, since the upper annular plane 5 of the upper case 2, the inner upper annular projecting surface 90, and the outer upper annular projecting surface 91 are supported by a line contact or a strip-shaped contact with a minute width against the thrust load, the surface pressure (unit The sliding frictional resistance is reduced by increasing the load per area), and the sliding frictional resistance due to the surface of the lubricant filled in the annular recess 84 in contact with the upper annular plane 5 is very small. Extremely low sliding frictional resistance can be obtained. Therefore, relative rotation of the lower case 41 in the R direction around the axis O of the upper case 2 with respect to the upper case 2 can be performed with extremely low sliding frictional resistance.

  Even when a bending deformation occurs in the thrust sliding bearing piece 71, the thrust sliding bearing piece 71 has a lower annular surface from the upper annular edge 121 connected to the inner upper annular edge 76 of the upper annular surface 75. 77, an inner frustoconical surface 79 having a diameter reduced toward the lower annular edge 122 connected to the inner lower annular edge 78, and an upper annular edge 123 connected to the outer upper annular edge 80 of the upper annular surface 75. And the outer frusto-conical surface 82 which is enlarged from the lower annular edge 124 connected to the outer lower annular edge 81 of the lower annular surface 77 to the inner annular conical surface 79. The outer peripheral surface 47 of the annular protrusion 45 of the case 41 and the outer frusto-conical surface 82 do not interfere with the inner peripheral surface 46 of the annular protrusion 49, and inhibit the reduction of the sliding frictional resistance due to interference during relative rotation. There is no.

  As shown in FIG. 4, the thrust slide bearing 1 is integrally formed on the annular lower surface 53 of the lower annular portion 43 of the lower case 41 with an inner peripheral surface having the same diameter as the inner diameter of the insertion hole 42. A cylindrical portion 54 may be further provided.

  According to the thrust slide bearing 1 having the cylindrical portion 54 on the annular lower surface 53 of the lower annular portion 43 of the lower case 41, the upper spring seat 112 of the coil spring 111 in the strut suspension as shown in FIG. The mounting operation between the hydraulic damper and the mounting member 114 to which the piston rod 113 is fixed is facilitated.

  In this case, the upper part of the piston rod 113 extends in the circumferential direction R around the axis O with respect to the upper case 2 and the lower case 41 in the circular hole 3 of the upper case 2 and the insertion hole 42 of the lower case 41 of the thrust slide bearing 1. It is inserted so as to be rotatable.

  In the strut type suspension mounted via the thrust slide bearing 1 as shown in FIG. 5, the relative rotation in the circumferential direction R around the axis O of the upper spring seat 112 via the coil spring 111 during the steering operation. Is smoothly performed by relative rotation of the lower case 41 with respect to the upper case 2 in the same direction.

  Further, as shown in FIGS. 6 and 7, the thrust slide bearing 1 is separated radially outward from the periphery of the circular hole 3 and radially inward with respect to the inner peripheral surface 7 of the cylindrical engagement hanging portion 6. Cylindrical suspension that is formed integrally with the upper annular plane 5 at a predetermined interval and that forms an upper outer annular groove 10 in cooperation with the inner circumferential surface 7 of the cylindrical engagement hanging portion 6 on the outer circumferential surface 9. The upper case 2 that further includes the portion 11 and the outer annular surface 47 of the annular protrusion 45 are integrally formed on the lower annular plane 44 at a predetermined distance radially outward from the outer circumferential surface 47. The lower case 41 may further include an annular protrusion 57 that forms a lower outer annular groove 56 in cooperation with the inner peripheral surface 46 of the annular protrusion 49 on the outer peripheral surface 55.

  In the upper case 2 and the lower case 41, the upper case 2 has an annular protrusion 49 disposed in the upper outer annular groove 10, while the cylindrical hanging portion 11 is disposed in the lower outer annular groove 56 and the annular protrusion 57. The annular engagement portion 8 formed on the inner peripheral surface of the end of the cylindrical engagement hanging portion 6 is overlapped with the annular projection 49 in the radial direction X, and the outer periphery of the lower end of the annular projection 49 of the lower case 41 The lower case 41 is combined with an elastic engagement with an annular engagement portion 50 formed on the surface.

  Also in the thrust sliding bearing 1 shown in FIG. 6, the thrust sliding bearing piece 71 includes an inner frustoconical surface 79 having an inner diameter larger than the outer diameter of the outer peripheral surface 47 of the annular protrusion 45 of the lower case 41, and the lower case. 41 and an outer frusto-conical surface 82 having an outer diameter smaller than the inner diameter of the inner peripheral surface 46 of the annular protrusion 49, and the lower annular surface 77 as the bottom surface 51 of the lower annular recess 48. The upper annular surface 75 is protruded from the opening 52 of the lower annular recess 48 so that the inner upper annular projecting surface 90 and the outer upper annular projecting surface 91 are in the upper circular shape. The upper case 2 is in contact with the annular flat surface 5 and closed with the upper annular flat surface 5 at the opening 83 of the annular concave portion 84 filled with the lubricant, and the upper case 2 has an inner circumference at the end of the cylindrical engagement hanging portion 6. The annular engagement portion 8 formed on the surface is connected to the annular protrusion 49 of the lower case 41. The annular engagement portion 50 formed on the outer peripheral surface of the end is elastically mounted is combined to the lower case 41.

  According to the thrust slide bearing 1 shown in FIG. 6, the upper case 2 has the cylindrical hanging portion 11 arranged in the lower outer annular groove 56 so as to overlap the annular protrusion 57 and the annular protrusion 49 in the radial direction X, Since the engaging portions 8 and 50 are elastically attached to each other and combined with the lower case 41, the overlapping portion in the radial direction X of the cylindrical hanging portion 11, the annular protrusion 57, and the annular protrusion 49, and the engaging portion 8 and As a result of the formation of the sealing portion by the labyrinth action between the elastic mounting portions of 50, entry of foreign matter such as dust into the sliding surface between the upper and lower cases 2 and 41 is prevented.

  Further, as shown in FIG. 8, the thrust slide bearing 1 has an inner peripheral surface having the same diameter as the inner diameter of the circular hole 3 at the center of the upper annular plane 5, and the inner peripheral surface of the cylindrical hanging portion 11. 12 is formed integrally with the upper annular plane 5 of the upper annular portion 4 at a predetermined distance radially inward and cooperates with the inner peripheral surface 12 and the upper annular plane 5. The upper case 2 further includes a cylindrical hanging portion 14 that forms a wide upper annular recess 13, and the annular protrusion 45 extends radially outward through the insertion hole 42 via the annular shoulder 59. It may be adjacent.

  In the thrust sliding bearing 1 shown in FIG. 8, the upper case 2 has the lower end surface of the cylindrical hanging portion 14 facing the upper surface of the annular shoulder portion 59 with a gap and the cylindrical hanging portion 14 is superimposed on the annular protrusion 45 in the radial direction X. The annular engaging portions 8 and 50 are elastically attached to each other and combined with the lower case 41.

  According to the thrust slide bearing 1 shown in FIG. 8, the upper case 2 has an annular protrusion with the cylindrical hanging portion 14 superimposed on the annular protrusion 45 in the radial direction and the cylindrical hanging portion 11 is arranged in the lower outer annular groove 56. 57 and the annular protrusion 49 are overlapped in the radial direction, and the annular engaging portions 8 and 50 are elastically mounted to be combined with the lower case 41, so that the overlapping portion of the cylindrical hanging portion 14 and the annular protrusion 45 is combined. As a result of forming a sealing portion by a labyrinth action in the radial overlapping portion of the cylindrical hanging portion 11 and the annular protrusion 57 and the annular protrusion 49 and the elastic mounting portion between the engaging portions 8 and 50, the upper and lower cases Intrusion of foreign matter such as dust into the sliding surface between 2 and 41 is prevented.

  Further, as shown in FIG. 9, the thrust sliding bearing 1 is a cylinder that forms a wide upper annular recess 13 on the outer peripheral surface 16 in cooperation with the inner peripheral surface 12 of the cylindrical hanging portion 11 and the upper annular plane 5. The hanging portion 14 is adjacent to the circular hole 3 in the central portion of the upper annular portion 4 via the annular shoulder portion 15 in the radially outward direction, while the lower case 41 is located in the central portion of the lower annular plane 44. An annular protrusion is formed so as to have an inner peripheral surface having the same diameter as the inner diameter of the insertion hole 42 formed in the outer peripheral surface 60 and to form a lower inner annular groove 62 on the outer peripheral surface 60 in cooperation with the inner peripheral surface 61 of the annular protrusion 45. An annular protrusion 63 formed integrally with the lower annular plane 44 of the lower annular part 43 at a predetermined interval radially inward with respect to the part 45, and formed. Also good.

  In the thrust sliding bearing 1 shown in FIG. 9, the upper case 2 has an annular shoulder 15 with its lower surface facing the upper end surface of the annular projection 63 with a gap and a cylindrical hanging portion 14 arranged in the lower inner annular groove 62. The projection 45 and the annular projection 63 are overlapped in the radial direction, the cylindrical hanging portion 11 is arranged in the lower outer annular groove 56, and the annular projection 57 and the annular projection 49 are overlapped in the radial direction X, respectively. The joint portions 8 and 50 are elastically attached to each other and combined with the lower case 41.

  According to the thrust slide bearing 1 shown in FIG. 9, the upper case 2 has a cylindrical hanging portion 14 arranged in the lower inner annular groove 62 so as to overlap the annular protrusion 45 and the annular protrusion 63 in the radial direction. 11 is arranged in the lower outer annular groove 56 and overlapped with the annular projection 57 and the annular projection 49 in the radial direction X, respectively, and the annular engagement portions 8 and 50 are elastically mounted to be combined with the lower case 41. Therefore, the overlapping portion in the radial direction X of the cylindrical hanging portion 14 and the annular protrusion 45 and the annular protruding portion 63, and the overlapping portion and the engagement of the cylindrical hanging portion 11, the annular protrusion 57 and the annular protrusion 49 in the radial direction X As a result of further forming a sealing portion by labyrinth action in the elastic mounting portion between the joint portions 8 and 50, the upper annular surface 75 as the sliding surface is formed between the upper and lower cases 2 and 41, particularly from the inner peripheral surface side. Intrusion of foreign matter such as dust is further prevented.

  Further, as shown in FIG. 10, the thrust slide bearing 1 is arranged so that the upper case 2 forms an upper inner annular groove 19 on the outer peripheral surface 17 in cooperation with the inner peripheral surface 18 of the cylindrical hanging portion 14. A cylindrical hanging portion 20 is further provided integrally with the lower surface of the annular shoulder portion 15 of the upper annular portion 4 with an inner peripheral surface having the same diameter as the inner diameter of the circular hole 3 at the center of the annular portion 4. The annular protrusion 63 is integrally formed on the upper surface of the annular shoulder portion 59 of the lower annular portion 43 so as to be radially outward from the insertion hole 42 at the center of the lower annular portion 43.

  In the thrust sliding bearing 1 shown in FIG. 10, the upper case 2 has the lower end surface of the cylindrical hanging portion 20 facing the upper surface of the annular shoulder portion 59 of the lower annular plane 44 with a gap, and the cylindrical hanging portion 20 is formed into an annular protrusion. 63 is superposed in the radial direction X, the annular protrusion 63 is arranged in the upper inner annular groove 19, and the annular protrusion 63 is superposed in the radial direction X on the cylindrical hanging part 20 and the cylindrical hanging part 14, respectively. 14 is arranged in the lower inner annular groove 62 so as to overlap the annular protrusion 45 and the annular protrusion 63 in the radial direction X, respectively, and the cylindrical hanging part 11 is arranged in the lower outer annular groove 56 so that the annular protrusion 57 and the annular protrusion are arranged. The annular engaging portions 8 and 50 are elastically attached to the portion 49 in the radial direction X, and are combined with the lower case 41.

  According to the thrust slide bearing 1 shown in FIG. 10, the upper case 2 has a cylindrical hanging portion 20 superimposed on the annular protrusion 63 in the radial direction X, and the annular protrusion 63 is disposed in the upper inner annular groove 19. The hanging part 14 is arranged in the lower inner annular groove 62 and overlapped with the annular protrusion 45 and the annular protrusion 63 in the radial direction X, respectively. The cylindrical hanging part 11 is arranged in the lower outer annular groove 56 and the annular protrusion 57 and Since the annular engaging portions 8 and 50 are elastically mounted on the annular protrusion 49 in the radial direction X and combined with the lower case 41, the radial direction between the cylindrical hanging portion 20 and the annular protrusion 63 is obtained. X overlapping portion, overlapping portion in the radial direction X between the cylindrical hanging portion 14 and the annular protrusions 63 and 45, overlapping portion in the radial direction X and engagement between the cylindrical hanging portion 11 and the annular protrusion 57 and the annular protrusion 49 A sealing part by a labyrinth action is further provided on the elastic mounting part between the parts 8 and 50 Results are made, on, foreign objects such as dust to the sliding surface between the lower case 2 and 41 invasion is further prevented.

  As shown in FIG. 12, the thrust slide bearing 1 is further integrated with an upper annular portion 4 having a circular hole 3 at the center, and an inner peripheral surface having the same diameter as the inner diameter of the circular hole 3. A cylindrical engagement hanging portion 6 formed integrally with the outer peripheral edge of the upper annular portion 4 at a predetermined distance radially outward from the outer peripheral surface 22 of the cylindrical portion 21. An annular engaging portion 8 integrally formed at the end of the inner peripheral surface 7 of the cylindrical engagement hanging portion 6, an annular protrusion 23 integrally projecting downward from the lower end portion of the cylindrical portion 21, and an annular shape An annular projection that protrudes downward integrally from the lower end of the cylindrical portion 21 so as to form an annular recess 24 in cooperation with the projection 23 and has a tapered surface 25 on the outer surface and tapers downward. 26, the lower annular portion 43 having the insertion hole 42 at the center, and the inner diameter of the insertion hole 42. A cylindrical portion 65 integrally formed on the annular lower surface 53 of the lower annular portion 43 with an inner peripheral surface 64 having the same diameter, an annular protrusion 45 integrally formed on the lower annular plane 44, an annular projection An annular protrusion 49 integrally formed on the outer peripheral edge of the lower annular portion 43 at a predetermined interval radially outward with respect to the outer peripheral surface 47 of the portion 45, and an outer peripheral surface of the annular protrusion 49 A lower case having an annular engaging portion 50 formed at the lower end, an annular protrusion 66 extending radially inward at the lower end of the inner peripheral surface 64 of the cylindrical portion 65, and an annular recess 67 formed in the annular protrusion 66. 41, the outer peripheral surface 22 of the cylindrical portion 21 is slidably contacted with the inner peripheral surface 64 of the cylindrical portion 65, the engaging portion 8 is elastically attached to the engaging portion 50, and the annular protrusion 26 is formed into an annular concave portion. 67, the upper case 2 may be combined with the lower case 41.

  Also in the thrust slide bearing 1 shown in FIG. 12, the thrust slide bearing piece 71 is the same as the thrust slide bearing piece 71 shown in FIG. 1, and the lower annular protrusion 93 of the lower annular surface 77 is formed on the lower case 41. The lower annular flat surface 44 defining the bottom surface 51 of the lower annular recess 48 is slidably contacted, and the upper annular surface 75 is protruded from the opening 52 of the lower annular recess 48 so that the inner upper annular projecting surface 90 and The outer upper annular projection 91 is brought into contact with the upper annular plane 5 of the upper case 2, and the opening 83 of the annular recess 84 filled with the lubricant is closed by the upper annular plane 5 of the upper case 2. The lower cases 2 and 41 are arranged.

  According to the thrust sliding bearing 1 shown in FIG. 12, similarly to the above-described examples, the relative rotation in the circumferential direction R between the upper case 2 and the lower case 41 under the thrust load is smoothly allowed to be steered. In addition to the smooth operation, the synthetic resins in the radial bearing portion formed between the outer peripheral surface 22 of the cylindrical portion 21 of the upper case 2 and the inner peripheral surface 64 of the cylindrical portion 65 of the lower case 41 Thus, relative rotation in the circumferential direction R between the upper case 2 and the lower case 41 under a radial load can be smoothly allowed.

  In each thrust sliding bearing 1 described above, the upper annular portion 4 of the upper case 2 has an annular shape having a predetermined width radially outward from the outer peripheral edge of the circular hole 3, as shown in FIGS. A circular belt-like flat surface 28 and an annular upper surface 27 having a downwardly truncated frusto-conical surface 30 from the outer peripheral edge of the circular belt-like flat surface 28 to the cylindrical outer peripheral surface 29 of the cylindrical engagement hanging portion 6. As shown in FIGS. 9 and 10, a circular belt-like protrusion 31 that is integrally formed on the circular belt-like plane 28 so as to protrude upward in the axial direction from the circular belt-like flat surface 28, and the outer side of the circular belt-like protrusion 31. A downwardly truncated frustoconical surface 30 may be provided from the periphery to the cylindrical outer peripheral surface 29 of the cylindrical engagement hanging portion 6.

  As shown in FIG. 11, a thrust slide bearing 1 having an upper case 2 having an annular upper surface 27 composed of an annular circular belt-like plane 28 and a frustoconical surface 30 and incorporated in a strut type suspension, Only in the annular circular belt-like plane 28 is in contact with the lower surface 115 of the vehicle body side mounting member 114, while the other surface maintains the space S with the lower surface 115 of the vehicle body side mounting member 114, and And the upper spring seat sheet 112 facing the lower surface 115, the cylindrical hanging portion 11 and the annular projecting portion are provided even when a variable load such as a tilt acts on the vehicle body side mounting member 114. 57 and the annular protrusion 49 in the radial direction X and the elastic mounting portion between the engaging portion 8 and the engaging portion 50 do not interfere with each other. Deformation, damage, can avoid the problem of breakage and the like.

  As described above, in the thrust slide bearing 1 of the present invention, the upper annular plane 5 of the upper case 2, the inner upper annular projecting surface 90, and the outer upper annular projecting surface 91 are supported by a line contact or a strip-shaped contact with a minute width. Therefore, the sliding friction resistance is reduced by increasing the surface pressure (load per unit area), and the sliding friction resistance by the surface of the lubricant filled in the annular recess 84 contacting the upper annular plane 5 is Since it is very small, a very low sliding frictional resistance is obtained as a whole.

DESCRIPTION OF SYMBOLS 1 Thrust sliding bearing 2 Upper case 41 Lower case 71 Thrust sliding bearing piece 79 Inner side conical surface 82 Outer side conical surface 84 Annular recessed part 85 Annular inner bearing part 86 Annular outer side bearing part 88 Inner annular side surface 89 Outer annular side surface 1 Lower Side annular protrusion

Claims (25)

  An upper case made of a synthetic resin having an upper annular plane, and a lower surface facing the upper annular plane of the upper case that is superimposed on the upper case so as to be rotatable around the axis of the upper case A side annular plane, first and second annular projections concentrically formed on the lower annular plane, and a wide lower annular recess surrounded by the first and second annular projections, respectively. A lower case made of synthetic resin, an upper annular surface disposed in a lower annular recess of the lower case and in sliding contact with the upper annular plane, and a lower annular surface in sliding contact with the lower annular plane The inner frustoconical surface and the upper side which are reduced in diameter from the upper annular edge connected to the inner upper annular edge of the upper annular surface to the lower annular edge connected to the inner lower annular edge of the lower annular surface Lower from the upper annular edge connected to the outer upper annular edge of the toric surface Each has an outer frusto-conical surface that expands toward the lower annular edge connected to the outer lower annular edge of the annular surface, and is made of a synthetic resin disposed in the lower annular recess of the lower case. A thrust sliding bearing piece, and an upper annular surface of the thrust sliding bearing piece is arranged concentrically with a central annular concave surface defining an annular concave portion filled with a lubricant and the central annular concave surface. And an inner upper annular projecting surface and an outer upper annular projecting surface that are slidably in contact with the upper annular plane, and the lower annular surface of the thrust slide bearing piece is a lower case A thrust slide bearing made of synthetic resin having a lower annular projecting surface slidably contacting a lower annular plane of the lower case in the lower annular recess.   The central annular concave surface has an annular bottom surface and an inner annular side surface that expands from the outer annular edge that is connected to the inner peripheral edge of the annular bottom surface to the inner annular edge that is connected to the outer annular edge of the inner upper annular projection surface. And an outer annular side surface expanding from the inner annular edge connected to the outer peripheral edge of the annular bottom surface to the outer annular edge connected to the inner annular edge of the outer upper annular projection surface. A thrust sliding bearing made of synthetic resin according to 1.   The thrust slide bearing made of synthetic resin according to claim 2, wherein the lower annular projecting surface is arranged to face the annular bottom surface of the central annular concave surface in the axial direction.   The thrust slide bearing made of synthetic resin according to any one of claims 1 to 3, wherein the central annular concave surface is a curved concave surface.   The thrust sliding bearing made of synthetic resin according to any one of claims 1 to 4, wherein each of the inner upper annular projecting surface and the outer upper annular projecting surface is a curved convex surface.   The lower annular surface of the thrust sliding bearing piece is connected to the inner lower annular concave surface connected to the inner peripheral edge of the lower annular protruding surface by the outer annular edge, and to the outer peripheral edge of the lower annular protruding surface by the inner annular edge. An outer lower annular concave surface, an inner lower annular convex surface connected to the inner annular edge of the inner lower annular concave surface and the lower annular edge of the inner frustoconical surface, and an outer annular edge and outer outer rim of the outer lower annular concave surface The thrust sliding bearing made of synthetic resin according to any one of claims 1 to 5, further comprising an outer lower annular projecting surface connected to a lower annular edge of the conical surface.   The thrust slide bearing made of synthetic resin according to claim 6, wherein the lower annular projecting surface projects downward from the inner lower annular projecting surface and the outer lower annular projecting surface.   The thrust sliding bearing made of synthetic resin according to claim 6 or 7, wherein each of the inner lower annular concave surface and the outer lower annular concave surface is a curved concave surface.   The thrust sliding bearing made of synthetic resin according to any one of claims 6 to 8, wherein each of the inner lower annular projecting surface and the outer lower annular projecting surface is a curved convex surface.   The thrust slide bearing made of synthetic resin according to any one of claims 1 to 9, wherein the lower annular projecting surface is a curved convex surface.   The upper case has an upper annular plane on the lower surface and a circular hole in the center, and a cylindrical engagement hanging portion integrally formed on the outer peripheral edge of the upper annular portion And an annular engagement portion formed on the inner peripheral surface of the cylindrical engagement hanging portion, and the lower case has a lower annular plane on the upper surface and the circle at the center portion. A lower annular portion having an insertion hole concentric with the hole, the first annular protrusion is formed integrally with the lower annular portion, and the second annular protrusion is The lower annular recess is formed integrally with the outer peripheral edge of the lower annular portion at a predetermined interval radially outward with respect to the first annular protrusion. The lower case is defined by the outer peripheral surface of the second annular projection, the inner circumferential surface of the second annular projection, and the lower annular plane. Together The upper case is further combined with the lower case by elastically attaching the annular engagement portion to the annular engagement portion of the lower case. A thrust sliding bearing made of synthetic resin as described in 1.   The upper case is spaced radially outward from the peripheral edge of the circular hole in the center of the upper annular portion, and is spaced above the inner peripheral surface of the cylindrical engagement droop by a predetermined distance radially inward. A first cylindrical hanging portion formed integrally with the annular portion and forming an upper outer annular groove in cooperation with the inner circumferential surface of the cylindrical engagement hanging portion on the outer circumferential surface; The case is integrally formed with the lower annular portion at a predetermined interval radially outward with respect to the outer peripheral surface of the first annular protrusion, and the second annular protrusion is formed on the outer peripheral surface. The upper case further includes a third annular protrusion that cooperates with the inner peripheral surface to form a lower outer annular groove, and the upper case has a second annular protrusion disposed in the upper outer annular groove. The cylindrical hanging portion is arranged in the lower outer annular groove and is superposed in the radial direction on the second and third annular protrusions, and combined with the lower case. Synthetic resin-made thrust sliding bearing according to claim 11.   The upper cylindrical portion is integrally formed with a predetermined distance radially inward with respect to the inner peripheral surface of the first cylindrical hanging portion and cooperates with the inner peripheral surface and the upper annular portion. And a second cylindrical hanging portion that forms a wide upper annular recess, and the first annular protrusion is adjacent to the insertion hole radially outward via an annular shoulder, The upper case is assembled to the lower case by causing the lower end surface of the second cylindrical hanging portion to face the upper surface of the annular shoulder portion with a gap and overlapping the second cylindrical hanging portion radially with the first annular protrusion. The thrust sliding bearing made of a synthetic resin according to claim 12, which is combined.   The thrust sliding bearing made of a synthetic resin according to claim 13, wherein the second cylindrical hanging portion has an inner peripheral surface having the same diameter as a circular hole in a central portion of the upper annular portion.   The thrust slide bearing made of a synthetic resin according to claim 13, wherein the second cylindrical hanging portion is adjacent to a circular hole in a central portion of the upper annular portion via a circular shoulder portion radially outward.   The lower case has a predetermined interval radially inward with respect to the first annular protrusion so as to form a lower inner annular groove in cooperation with the inner peripheral surface of the first annular protrusion on the outer peripheral surface. The upper case further includes a fourth annular protrusion integrally formed on the upper surface of the annular shoulder portion of the lower annular portion, and the upper case has a second cylindrical hanging portion disposed in the lower inner annular groove. The synthetic resin thrust sliding bearing according to claim 13, wherein the first annular protrusion and the fourth annular protrusion are overlapped in the radial direction and combined with the lower case.   The thrust slide bearing made of synthetic resin according to claim 16, wherein the fourth annular protrusion has an inner peripheral surface having the same diameter as an insertion hole formed in a central portion of the lower annular portion.   The fourth annular protrusion is integrally formed on the upper surface of the annular shoulder portion of the lower annular portion, spaced radially outward from the insertion hole in the center portion of the lower annular portion. A thrust sliding bearing made of the described synthetic resin.   The upper case has an inner peripheral surface having the same diameter as the circular hole at the center of the upper annular portion so as to form an upper inner annular groove in cooperation with the inner peripheral surface of the second cylindrical hanging portion on the outer peripheral surface. A third cylindrical hanging portion formed integrally with the lower surface of the annular shoulder portion of the upper annular portion; and a lower end surface of the third cylindrical hanging portion is connected to the annular shoulder portion of the lower annular portion. The upper cylindrical surface is made to face the upper surface with a gap and the third cylindrical hanging portion is radially overlapped with the fourth annular protrusion, and the fourth annular protrusion is arranged in the upper inner annular groove, and is combined with the lower case. A thrust sliding bearing made of synthetic resin according to claim 18.   The synthetic resin thrust according to claim 11, wherein the lower case includes a cylindrical portion formed integrally with the lower annular portion having an inner peripheral surface having the same diameter as the insertion hole of the central portion. Plain bearing.   The upper case further includes a cylindrical portion formed integrally with the upper annular portion with an inner peripheral surface having the same diameter as the inner diameter of the circular hole at the center of the upper annular portion, and the outer peripheral surface of the cylindrical portion. The thrust sliding bearing made of synthetic resin according to claim 20, wherein the sliding contact is made in sliding contact with the inner peripheral surface of the cylindrical portion of the lower case and combined with the lower case.   The upper annular portion has a circular belt-like plane having a predetermined width radially outward from the outer peripheral edge of the circular hole in the central portion, and from the outer peripheral edge of the circular belt-like flat surface to the cylindrical outer peripheral surface of the cylindrical engagement hanging portion. The thrust sliding bearing made of a synthetic resin according to claim 11, comprising an annular upper surface having a downwardly inclined truncated cone surface.   The upper annular portion further includes a circular belt-like protrusion that integrally protrudes upward in the axial direction from a circular belt-like plane having a predetermined width radially outward from the outer peripheral edge of the circular hole in the central portion. Item 23. A synthetic resin thrust slide bearing according to Item 22.   The synthetic resin thrust sliding bearing according to any one of claims 1 to 23, wherein the upper case, the lower case, and the thrust sliding bearing piece are made of a thermoplastic synthetic resin.   The synthetic resin thrust sliding bearing according to claim 24, wherein the upper case and the lower case are made of polyacetal resin, polyamide resin, or polyester resin, and the thrust sliding bearing piece is made of polyamide resin, polyolefin resin, or polyester resin.

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