JPH0131777Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Field of Industrial Application) The present invention relates to a synthetic resin thrust bearing, particularly a synthetic resin thrust bearing suitable for being incorporated into a strut thrust type suspension (McPherson type) in a four-wheeled vehicle. (Prior art) Strut-type suspensions are generally used mainly for the front wheels of four-wheeled vehicles, and are suspensions that combine coil springs with a strut assembly that has a hydraulic shock absorber built into an outer cylinder that is integrated with the main shaft. It is. Among the above suspensions, when the strut assembly rotates with the coil spring due to steering operation, there are types in which the piston rod of the assembly rotates, and there are types in which the piston rod does not rotate, but in both types, the strut assembly does not rotate. In order to allow smooth rotation of the coil spring, a bearing is required between the mounting member of the vehicle body and the upper spring seat of the coil spring. Conventionally, rolling bearings using balls or needles, or sliding bearings made of synthetic resin have been used for bearings at this location. FIG. 4 shows a conventional example of a strut assembly using a synthetic resin sliding bearing. In the figure, strut 1 with a built-in shock absorber that constitutes strut assembly A is shown.
The piston rod 2 has one end connected to the strut 1.
It is inserted into the shock absorber of the vehicle, and its other end protrudes from the shock absorber and is fixed with a nut 4 to a mounting member 3 which is supported by the vehicle body via a mount insulator made of a rubber elastic body. A coil spring 7 is disposed between a lower spring seat 5 fixed to the outer peripheral surface of the strut 1 and an upper spring seat 6 facing the lower spring seat 5 and loosely inserted on the outer periphery of the piston rod 2. has been done. Between the plane part 8 of the upper spring seat sheet 6 and the mounting member 3, there is a cylindrical part 1 having an insertion hole 9 on the inner surface.
A synthetic resin thrust bearing 13 consists of a cylindrical portion 10 and a flange portion 11 integrally formed at one end of the cylindrical portion 10, and a synthetic resin thrust bearing 13 has a dust seal 12 made of a rubber elastic body attached to the outer peripheral surface of the flange portion. The inner surface insertion hole 9 is fitted into the outer peripheral surface of the piston rod 2, and the outer peripheral surface of the cylindrical portion is fitted into the hole in the flat part 8 of the upper spring seat seat 6. (Problems to be Solved by the Invention) In the above-mentioned conventional technology, the dust seal attached to the outer circumferential surface of the flange of the thrust bearing is a sliding member that rotates relatively for the purpose of preventing dust from entering the sliding surface of the bearing. Since it is disposed in close sliding contact between the moving surfaces, there is a drawback that the sliding friction force is high during steering operation, increasing the steering force. In addition, since the mounting member that is the mating material of the thrust bearing is usually formed by sheet metal processing, its flatness and flatness are not sufficient, and this causes uneven contact, etc., which causes uneven wear on the bearing. It has the disadvantage of causing The present invention has been developed to solve the above-mentioned drawbacks of the conventional technology. The purpose of this invention is to obtain a synthetic resin thrust bearing that can absorb the degree of malfunction. (Means for solving the problems) In order to achieve the above-mentioned object, the present invention adopts the following technical means, that is, the configuration. Synthetic resin lower case, upper case and upper case.
It consists of a synthetic resin bearing piece placed inside a lower case, and the lower case is integrally formed with a cylindrical part having an insertion hole on the inner surface and a part of the cylindrical part protruding from the outer peripheral surface of the cylindrical part. The upper case includes a wide flange, an annular protrusion integrally formed on the outer periphery of the flange, and inner and outer engagement portions formed on the outer circumferential surface and inside the end of the annular protrusion. a circular hole formed in the center of the flat part, an annular hanging part integrally formed on the outer periphery of the flat part, and an engagement step part formed on the lower surface of the hanging part; The upper case is configured such that the engagement stepped portion of the annular hanging portion is elastically attached to the inner peripheral engagement portion of the annular protrusion of the lower case so as to be relatively rotatable, and the elastic attachment portion is sealed. The upper surface of the upper case includes a reinforcing disk having a circular hole in the center, a cylindrical portion that hangs down to cover the upper surface of the disk and the outer peripheral surface, and an inwardly narrowed end of the cylindrical portion. An elastic seal body made of a rubber elastic body is provided with an annular lip portion, and the annular lip portion is disposed in close contact with the outer peripheral engagement portion of the annular protrusion of the lower case. This is a synthetic resin thrust bearing characterized in that a synthetic resin bearing piece is arranged with its end surface in sliding contact with the flat lower surface of the upper case and the upper surface of the wide flange of the lower case. In the above configuration, the synthetic resin that makes up the upper and lower cases must have excellent mechanical properties such as abrasion resistance, impact resistance, and creep resistance. It is particularly preferable that the synthetic resin bearing pieces have self-lubricating properties; for example, polyacetal resins, polyamide resins, polyester resins such as polybutylene terephthalate (PBT), and polyolefin resins such as polyethylene and polypropylene are well used. In addition, polycarbonate resin can also be used. The upper and lower cases are made of the same synthetic resin as the bearing piece, but in particular a synthetic resin with a good combination of friction characteristics and relatively high rigidity is used for the bearing piece. Preferably, it is a resin material. Examples of desirable combinations are shown in the table below.

【table】

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to FIGS. 1 and 2 of the accompanying drawings showing embodiments thereof. 20 is a synthetic resin thrust bearing, and the thrust bearing 20 includes a synthetic resin lower case 30, a synthetic resin upper case 40, a synthetic resin bearing piece 50 disposed inside the upper and lower cases 40 and 30, and the upper case 4.
0, and an elastic sealing body 60 disposed on the upper surface of 0. The lower case 30 includes a cylindrical portion 32 having an insertion hole 31 on its inner surface, a wide flange portion 33 integrally formed with a portion 32a of the cylindrical portion 32 protruding from the outer peripheral surface of the cylindrical portion 32, and the flange portion. An annular protrusion 34 integrally formed on the outer circumferential edge of the protrusion 33, and inner and outer circumferential engaging portions 35, 3 formed on the outer circumferential surface and inside the end of the protrusion 34.
It is equipped with 6. The inner and outer circumferential engaging portions 35 and 36 are tapered surface portions formed from the inner and outer circumferential surfaces of the annular protrusion to the tip. The upper case 40 includes a disk-shaped flat part 41, a circular hole 42 formed in the center of the flat part 41, and an annular hanging part 4 integrally formed on the outer peripheral edge of the flat part 41.
3 and an engagement step portion 44 formed on the outer peripheral surface of the hanging portion 43. The engagement step portion 44 is formed of a tapered surface portion corresponding to the tapered surface portion constituting the inner peripheral engagement portion 35 of the annular protrusion portion 34 of the lower case 30. The upper case 40 connects the engagement step portion 44 of the annular hanging portion 43 to the inner peripheral engagement portion 35 of the lower case 30.
They are elastically mounted to allow relative rotation, and a labyrinth-effect sealing portion is formed at the elastic mounting portion. The synthetic resin bearing piece 50 is formed into a disk shape having an inner hole 51 having an inner diameter larger than the outer diameter of the protruding cylindrical part 32a of the lower case 30 and an outer diameter smaller than the inner diameter of the annular hanging part 43 of the upper case 40. ing. On both end surfaces of the bearing piece 50, a plurality of concave grooves 52 are formed radially in the circumferential direction from the inner hole 51 to the outer peripheral surface.
Each is formed with a phase difference of 30 degrees,
The groove 52 serves as a reservoir for lubricating oil such as grease. The bearing piece 50 has an inner hole 51 connected to the lower case 30.
The projecting cylindrical portion 32a is engaged with the outer peripheral surface of the protruding cylindrical portion 32a, and both end surfaces are slidably contacted with the lower surface of the flat portion 41 of the upper case 40 and the upper surface of the wide flange portion 33 of the lower case 30, respectively, and are disposed within the upper and lower cases 40, 30. ing. The elastic seal body 60 includes a reinforcing disk 62 having a circular hole 61 in the center, a cylindrical portion 63 that hangs down to cover the upper surface of the reinforcing disk 62 and the outer peripheral surface, and an inner portion at the end of the cylindrical portion 63. It is composed of a rubber elastic body 65 having an annular lip portion 64 that narrows at the end. The elastic seal body 60 has a reinforcing disk 62 located on the upper surface of the flat part 41 of the upper case 40, and an annular lip part 64 located on the annular protrusion 34 of the lower case 30.
It is disposed in close contact with the outer circumferential engaging portion 36 of. FIG. 3 shows a strut assembly A in which the synthetic resin thrust bearing 20 having the above-mentioned structure is used.
The following is an example of how this method is applied. That is, the insertion hole 31 of the cylindrical part 32 of the lower case 30 and the circular hole 42 of the flat part 41 of the upper case 40.
is inserted into the outer peripheral surface of the piston rod 2 of the strut 1, and the outer peripheral surface of the cylindrical portion 32 of the lower case 30 is fitted into the hole of the upper spring seat sheet 6, and the lower surface of the wide flange 33 of the lower case 30 is inserted into the seat 6. The elastic seal body 60 disposed on the upper surface of the upper case 40 is placed in contact with the vehicle body side mounting member 3. In this arrangement, the lower surface of the upper case 40, which serves as the bearing sliding surface, the upper surface of the wide flange 33 of the lower case, and the upper and lower surfaces of the bearing piece 50 are connected to the sealing portion formed in the upper and lower cases by the labyrinth action. Since it is protected by the elastic seal body 60 disposed over the sliding surface, dust and the like are prevented from entering the sliding surface. Furthermore, even if the mounting member 3 has a defect in flatness or flatness, the defect is absorbed by the seal body 60, so that uneven contact does not occur in the bearing, causing uneven wear. Never. (Effects) The synthetic resin thrust bearing of the present invention having the above-described configuration has the following unique effects. A sealing portion is formed by a labyrinth action at the elastic attachment portion between the engagement step portion of the upper case and the inner circumferential engagement portion of the annular projection portion of the lower case, and an elastic sealing body is disposed to cover the sealing portion. This prevents dust from entering the bearing sliding surface.
There is no increase in steering force during steering operations due to conventional dust seals made of rubber elastic bodies, and smooth steering operations can be performed over a long period of time. Since the sliding surface is made of a combination of synthetic resins with excellent self-lubricating properties, the coefficient of friction is small and stable steering force is maintained over a long period of time. Since the upper case and the lower case are assembled together by elastic attachment, the assembly work is extremely simple. Even if there is a problem with the flatness or planarity of the mounting member, the problem is absorbed by the elastic seal, so that uneven contact and uneven wear on the bearing will not occur.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a synthetic resin thrust bearing of the present invention, FIG. 2 is a plan view of a synthetic resin bearing piece, and FIG. 3 is a longitudinal sectional view showing an example in which the bearing is applied to a strut assembly. FIG. 4 is a longitudinal sectional view showing a conventional strut assembly. 20: Synthetic resin thrust bearing, 30: Lower case, 40: Upper case, 50: Bearing piece, 60: Elastic seal body, 32: Cylindrical part, 33: Wide flange part, 3
4: annular protrusion, 35, 36: inner and outer peripheral engagement parts,
41: Plane portion, 43: Annular hanging portion, 44: Engagement step portion, 62: Reinforcement disk, 64: Annular lip portion, 6
5: Rubber elastic body.

Claims (1)

[Scope of utility model registration request] Lower case 30 and upper case 40 made of synthetic resin
and synthetic resin bearing pieces 50 disposed inside the upper and lower cases. A wide flange 33 that is integrally formed in a protruding manner, an annular protrusion 34 that is integrally formed on the outer periphery of the flange, and inner and outer periphery engaging portions 35 that are formed on the inner and outer peripheral surfaces of the ends of the annular protrusion. , 36,
The upper case 40 includes a disk-shaped flat part 41, a circular hole 42 formed in the center of the flat part, an annular hanging part 43 integrally formed on the outer periphery of the flat part, and an outer periphery of the end of the hanging part. The upper case 40 has an engagement step 44 formed on a surface, and the upper case 40 has the engagement step 44 of the annular hanging portion 43 elastically attached to the inner peripheral engagement portion 35 of the annular protrusion of the lower case 30. The upper case 40 has a reinforcing disk 62 having a circular hole 61 in the center and a top surface of the disk. A cylindrical portion 6 that hangs down to cover and cover the outer peripheral surface.
3 and a rubber elastic body having an annular lip part 64 narrowing inwardly at the end of the cylindrical part. Synthetic resin bearing pieces 50 are disposed in close contact with the engaging portion 36, and in the upper and lower cases, synthetic resin bearing pieces 50 have end surfaces on the lower surface of the flat portion 41 of the upper case 40 and the upper surface of the wide flange portion 33 of the lower case 30, respectively. A synthetic resin thrust bearing characterized by being arranged in sliding contact.