JPH0446231A - Sliding bush - Google Patents

Abstract

PURPOSE:To improve durability by effectively preventing the slide movement between a slide contact cylinder body and a race metal fitting and projecting the slide contact cylinder body inward in the radial direction for the race metal fitting and installing a throttle part for pressing-deforming the outer peripheral surface of the slide contact cylinder body in the radial direction. CONSTITUTION:As for a slide contact cylinder body 22, the outer peripheral surface is fixed for the inner peripheral surface 24 of a race metal fitting 20, and the inner peripheral surface forms a spherical slide contact recessed surface 26 which corresponds to the slide contact projecting surface 14 of the spherical projection part 12 of a metal fitting 20 and is fitted in slidable manner with respect to the slide contact projection surface 14. A throttle part 46 projecting inward in the radial direction is formed on the race metal fitting 20. The throt tle part 46 effectively acts as a mechanical turn preventing mechanism between the race metal fitting 20 and the slide contact cylinder body 22, and the turn of the slide contact cylinder body 22 for the race metal fitting 20 is effectively prevented, and the abrasion of the slide contact cylinder body 22 caused by slide movement is prevented, and the durability of the slide contact cylinder body 22 can be improved very effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a sliding bushing, and particularly to a sliding bushing that can easily adjust sliding torque (sliding rigidity) and exhibits excellent durability. It is related to type bunshu.

(Background Art) Conventionally, as a type of joint device used in vehicle suspensions of automobiles, the
As shown in Publication No. 4 and Japanese Utility Model Application Publication No. 60-3335, etc., for a shaft fitting in which the outer circumferential surface of the intermediate portion in the axial direction is a sliding surface, a predetermined distance is placed on the outside of the sliding surface. The cylindrical race fittings are arranged coaxially so that they are separated from each other, and
By holding the sliding cylindrical body that is slidably fitted to the sliding surface of the shaft fitting with the race fitting, displacement in the torsional direction around the axis or in a prying direction inclined with respect to the axis can be prevented. A so-called sliding bushing is known, which has a structure in which the displacement of the bushing is allowed by sliding between the sliding surface of the shaft fitting and the inner circumferential surface of the sliding cylinder.

However, in such a sliding bushing, the sliding cylinder is divided into two parts in the axial direction, and after being inserted into the shaft fitting from both sides in the axial direction, it is integrally assembled with the race fitting. Because the structure is designed to be held in place, the structure is complicated and assembly work is troublesome.Additionally, due to the dimensional errors of each member, the sliding surface of the shaft fitting and the inner periphery of the sliding cylinder There was also the problem that the accuracy of the clearance between the sliding surface and the sliding surface decreased, making it difficult to obtain stable sliding performance.

Therefore, in Japanese Patent Application Laid-Open No. 62-8805, etc., the applicant of the present application has previously disclosed a technique in which a predetermined resin material is directly filled into the annular space formed between the shaft fitting and the race fitting to achieve a sliding contact. A sliding type bushing with a structure formed by forming a cylindrical body was revealed. That is, in such a sliding type bushing, since the sliding sleeve is assembled at the same time as its formation, the structure can be advantageously simplified and the assembly work can be made easier. In addition, since the inner circumferential surface of the sliding cylinder can advantageously correspond to the shape of the sliding surface of the shaft fitting, dimensional errors in the member can be absorbed, and excellent sliding performance can be stably exhibited. It can be done.

However, in a sliding type bushing having such a structure, the clearance between the sliding surface of the shaft fitting and the inner circumferential surface of the sliding cylinder prevents the cooling of the resin material forming the sliding cylinder. Since it is formed by shrinkage over time, it is possible to advantageously obtain a clearance of a substantially constant size, but on the other hand, the size is determined by the resin material, etc., and it is extremely difficult to change or adjust it. For this reason, it is extremely difficult to tune the sliding torque (sliding rigidity) at sliding parts, and when different sliding torques are required for various products, the required sliding torque can be adjusted depending on the product. Therefore, it was difficult to establish each of them, and there was still room for improvement.

In addition, in such a sliding bushing, the sliding sleeve is bonded to the race fitting at the same time as the sliding sleeve is formed. It was difficult to ensure sufficient adhesion between the body and the lace fittings, and in particular, the inner peripheral surface of the lace fittings was not surface-treated and was relatively rough. If sliding occurs between the sliding cylinder and the sliding cylinder, the sliding cylinder is likely to wear out, and its durability is significantly impaired.

(Problem to be solved) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problem to be solved is:
The sliding torque (sliding rigidity) between the sliding surface of the shaft fitting and the inner peripheral surface of the race fitting can be easily adjusted, and the sliding torque (sliding rigidity) between the sliding contact cylinder and the race fitting can be easily adjusted. An object of the present invention is to provide an improved sliding bushing in which sliding of the bushing can be effectively prevented and its durability can be advantageously improved.

(Solution Means) In order to solve this problem, the present invention provides a shaft fitting in which the outer circumferential surface of the axially intermediate portion is a sliding surface, and a predetermined distance from the outside of the sliding surface. A cylindrical race fitting is placed on the outside so that the shaft fitting and the race fitting are positioned apart from each other, and a sliding contact cylinder is arranged between the shaft fitting and the race fitting, so that the shaft fitting is placed on the inner circumferential surface of the race fitting. In a sliding type bushing in which the sliding surface of a metal fitting is slidably held via the sliding cylinder, the sliding cylinder is made of an elastic member, and with respect to the race metal fitting, protrudes radially inward,
It is characterized by the provision of a constriction portion that presses and deforms the outer circumferential surface of the sliding cylinder in the radial direction.

(Examples) Hereinafter, in order to clarify the present invention more specifically, examples of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show an example of a sliding bushing having a structure according to the present invention. In this figure, 10 is a shaft metal fitting exhibiting a substantially thick-walled cylindrical shape,
A spherical convex portion 12 having a spherical shape and projecting outward in the direction perpendicular to the axis is integrally formed in the central portion in the axial direction. The outer peripheral surface of the spherical convex portion 12 is a spherical sliding convex surface 14 . Furthermore, fitting grooves 18 extending in the circumferential direction are formed at both axial ends of the shaft fitting 10, into which dust seals 16, which will be described later, are fitted.

Further, on the outside of this shaft fitting 10, a race fitting 20 having a substantially thin-walled cylindrical shape is arranged. The lace fittings 20
has a cylindrical shape having an inner diameter that is a predetermined dimension larger than the outer diameter of the spherical protrusion 12 of the shaft fitting 10, and an axial length that is a predetermined dimension larger than the axial length of the spherical protrusion 12, and A through hole 28 for injecting a composition 38 mainly composed of a liquid prepolymer, which will be described later, is formed in the central portion in the axial direction. The race fitting 20 is arranged approximately coaxially with the shaft fitting 10 so as to be located radially outward of the spherical convex portion 12 of the shaft fitting 10 with a predetermined distance therebetween.

Furthermore, a sliding contact cylinder 22 having a substantially cylindrical shape is interposed in an annular space extending in the circumferential direction formed between the spherical convex portion 12 of the shaft fitting 10 and the race fitting 20. . The sliding contact cylinder 22 has its outer circumferential surface fixed to the inner circumferential surface 24 of the race fitting 20, while its inner circumferential surface is attached to the sliding convex surface 14 of the spherical convex portion 12 of the shaft fitting 20. A spherical concave sliding surface 26 corresponding to the convex sliding surface 14 is slidably fitted into the convex sliding surface 14 .

By the way, the sliding contact cylinder 22 is made of an elastic member having a predetermined elasticity, and in particular, in this embodiment, an elastic sliding member having self-lubricating properties using a thermosetting polyurethane elastomer is used. Consists of moving parts.

That is, such an elastic sliding member is disclosed in Japanese Patent Application Laid-Open No. 1-255719.
As shown in the publication, a composition made by using a liquid prepolymer of thermosetting polyurethane elastomer and blending 1 to 20 parts by weight of silicone oil per 100 parts by weight is molded, crosslinked, It is obtained by curing, and can exhibit elasticity due to the properties of the thermosetting polyurethane elastomer itself, and the silicone oil contained in the thermosetting polyurethane elastomer gradually oozes out to the surface. , it can permanently exhibit effective self-lubrication performance with bleedability. In addition, in order to crosslink and harden a composition consisting of a liquid prepolymer of a thermosetting polyurethane elastomer and silicone oil to form an elastic sliding member, various known methods must be used before molding the composition. A curing agent (crosslinking agent) will be appropriately blended.

Furthermore, the sliding cylinder 22 made of such an elastic sliding member is made of a composition consisting of a liquid prepolymer and silicone oil forming the elastic sliding member between the shaft fitting 1o and the race fitting 2o. By filling, crosslinking, and curing, it is formed directly between the two fittings 10 and 20.

That is, when forming the sliding contact cylinder 22, first, as shown in FIG. 32 and the upper mold 34, these shaft fittings 1o
and the race fitting 2o are set substantially coaxially with each other. That is, under such a set state, a molding space 36 for forming the sliding cylinder 22 is defined between the spherical convex portion 12 of the shaft fitting 10 and the race fitting 20. In addition, the inner circumferential surface 24 of the race fitting 20 may be provided with, if necessary,
Adhesive treatment is applied.

Under such conditions, as shown in FIG. 4, a predetermined amount of silicone oil is blended with the liquid prepolymer that provides the thermosetting polyurethane elastomer, and an appropriate curing agent is further blended as appropriate. Composition 38 consisting of
The material is guided through the sprue 40 of the molding die 30 and injected into the molding space 36 from the second day through the through hole of the race fitting 20, thereby being molded and hardened into a molded product of a predetermined shape within the molding space 36. Thus, the desired sliding contact cylinder 22 is obtained.

Therefore, in the sliding cylindrical body 22 obtained in this way, its outer peripheral surface is held by the inner peripheral surface 24 of the race fitting 20, while its inner peripheral surface (sliding concave surface 26) Shaft fitting 1
In addition to being molded into a shape extremely faithful to the sliding convex surface 14 of 0, a small clearance is advantageously created between the sliding concave surface 26 and the sliding convex surface 14 based on the shrinkage of the material after injection. By being able to form such a sliding contact cylinder 22
is fitted into the spherical convex portion 12 of the shaft fitting 10 in a spherical slidable manner.

In addition, in the sliding portion between the sliding concave surface 26 of the sliding cylinder 22 and the sliding convex surface 14 of the shaft fitting 10, as shown in FIG. In this case, a dust seal 16 is installed between the axial ends of the shaft fitting 10 and the race fitting 20 to prevent dirt, dust, etc. from entering the sliding portion. The dust seal 16 is made of a rubber elastic body and has a thin, substantially cylindrical shape, and one opening in the axial direction is a thick ring-shaped fitting part 42;
An annular mounting fitting 44 is vulcanized and bonded to the other opening in the axial direction. The fitting portion 42 is fitted into the fitting groove 18 provided in the shaft fitting 10, while the mounting fitting 44 is connected to the axial end surface of the sliding cylinder 22 and the axial end of the race fitting 20. By caulking and fixing between them, the shaft fitting 10 and the race fitting 20 are attached between their end portions.

Furthermore, after the sliding contact cylinder 22 is formed as described above, the race fitting 20 has the following features as shown in FIGS. 1 and 2.
With respect to a plurality of locations (in this example, locations) located at predetermined intervals in the circumferential direction in the axial center portion,
The lace fitting 2 is drawn by drawing process.
At a plurality of locations in the circumferential direction located in the axial center portion of 0, throttle portions 46 that protrude inward in the radial direction are formed, respectively.

That is, the constricted portion 4 formed on the race fitting 22
6, the outer peripheral surface of the sliding cylindrical body 22 is pressed in the radial direction and elastically deformed, and the sliding cylindrical body 22 is
A compression action is applied in the radial direction, whereby the sliding concave surface 26 of the sliding cylinder 22 and the shaft fitting 1
The magnitude of the clearance or contact pressure between the sliding surface and the sliding convex surface 14 of 0 can be adjusted as appropriate.

Therefore, in the sliding type bunsch having such a structure, by appropriately adjusting the size and protruding height of the constricted portion 460 in the race fitting 22, or the number of formed parts, etc., the sliding contact cylinder 22 and the shaft fitting can be easily The sliding torque (sliding rigidity) between the sliding surface and the sliding surface 10 can be tuned as appropriate, thereby making it possible to obtain a sliding type spring having an arbitrary sliding torque. In addition,
When adjusting the sliding torque using the constricted portion 46, it is better to set the sliding torque small before forming the constricted portion 46, so that the sliding torque can be adjusted over a wider range. desirable.

In addition, in such a sliding bushing, the sliding concave surface 26 of the sliding cylinder body 22 and the sliding convex surface 1 of the shaft fitting 10 before the constriction part 46 is formed on the race fitting 22.
The clearance between the sliding surface with the sliding cylinder 2
2 is formed to a substantially constant size based on the shrinkage of the material after injection. It is possible to advantageously manufacture a sliding type bushing that can exert the same sliding torque, and it also has the advantage that the sliding torque to be exerted can be easily set.

Furthermore, in the sliding type bushing as described above, the constricted portion 46 formed on the race fitting 20 enters into the concave portion formed on the outer peripheral surface of the sliding cylinder 22 due to the pressure of the constricted portion 46. Since the constricted portion 46 is positioned at , the constricted portion 46 can effectively function as a mechanical rotation prevention mechanism for the race fitting 20 and the sliding cylinder body 22. And thereby, the lace fittings 2
Rotation of the sliding cylinder 22 with respect to the angle can be advantageously prevented, and wear of the sliding cylinder 22 due to such sliding can be avoided, and the sliding cylinder 22 and, by extension, The durability of the dynamic bushing can be improved very effectively.

Further, in the sliding type bushing of this embodiment, since an elastic sliding member having elasticity and self-lubricating properties is used as the sliding cylinder 22, the sliding contact of the sliding cylinder 22 is This also has the advantage that it is not necessary to attach a low-friction cloth such as Teflon cloth to reduce sliding friction on the concave surface 26, and it is easy to manufacture.

Although one embodiment of the present invention has been described in detail above, this is a literal illustration, and the present invention is not to be construed as being limited only to this specific example.

For example, in the above embodiment, the present invention is applied to a so-called spherical sliding type bushing in which the sliding surface of the shaft fitting and the inner peripheral surface of the sliding cylinder are fitted in a spherical sliding manner. Although one specific example has been shown, the present invention also provides a cylindrical surface in which the sliding surface of the shaft fitting and the inner circumferential surface of the sliding cylindrical body are fitted to be slidable only around the axis. It can also be advantageously applied to a sliding bushing having a shaped sliding surface.

Further, in the above embodiment, the sliding cylinder was formed of an elastic sliding member that had both elasticity and self-lubricating properties, but the sliding cylinder was formed of a suitable elastomer that did not have self-lubricating properties. It is also possible to do so. Of course, if the sliding resistance of the elastomer used as the sliding cylinder is large,
It is desirable to secure sliding properties by fixing a sliding cloth made of low-friction fibers such as Teflon to the inner peripheral surface.

Furthermore, the shape, number, etc. of the constricted portions formed on the race fittings are adjusted as appropriate depending on the sliding torque etc. required of the product bushing, and are limited to those of the above embodiments. It will never happen.

Furthermore, since it is difficult to use a thick and highly rigid member for the race fitting due to the drawing process, a highly rigid outer cylinder is fitted and fixed on the outer circumferential surface of the race fitting. The race fitting may be attached to the connected member via the outer cylinder fitting.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. However, it goes without saying that all of these are included within the technical scope of the present invention as long as they do not depart from the gist of the present invention.

(Effects of the Invention) As is clear from the above description, in the sliding bushing structured according to the present invention, the shape and size of the constricted portion formed on the race fitting, or the amount of protrusion can be adjusted. As a result, the magnitude of the clearance or contact pressure between the sliding surface between the inner circumferential surface of the elastic member constituting the sliding cylinder and the sliding surface of the shaft fitting can be changed. The sliding torque between the surfaces can be tuned appropriately.

In addition, in such a sliding bushing, the constricted portion of the race fitting deforms the outer circumferential surface of the elastic member constituting the sliding cylinder and enters into the race of the sliding cylinder. Since it can also act as a mechanical rotation stopper mechanism for the metal fitting, the wear due to the sliding of the sliding cylinder against the race metal fitting can be effectively prevented, and its durability can be advantageously improved. It also has.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a sliding bushing constructed according to the present invention, and FIG. 2 is a cross-sectional view taken along the line -■ in FIG. Moreover, FIG. 3 is a cross-sectional explanatory diagram for explaining one manufacturing process of the sliding type bushing shown in FIG. 1, and FIG. It is a cross-sectional explanatory view for explanation. 10: Shaft fitting 14: Sliding convex surface 22: Sliding cylinder 30: Molding mold 46: Restricted portion 12: Spherical convex portion 20: Race fitting 26; Sliding concave surface 36: Molding space

Claims (1)

[Scope of Claims] With respect to a shaft fitting whose outer circumferential surface of the axially intermediate portion is a sliding surface, the shaft fitting is positioned at a predetermined distance outside the sliding surface;
A cylindrical race fitting is arranged externally, and a sliding contact cylinder is arranged between the shaft fitting and the race fitting, so that the sliding surface of the shaft fitting is arranged on the inner circumferential surface of the race fitting. In a sliding type bush which is slidably held via a sliding cylinder, the sliding cylinder is made of an elastic member, and protrudes radially inward with respect to the race fitting, A sliding type bushing characterized in that it is provided with a constriction portion that presses and deforms the outer circumferential surface of the sliding cylinder body in the radial direction.