JPS6246932Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a strut thrust bearing incorporated in a strut type suspension (McPherson type) in an automobile.

In general, strut-type suspensions are mainly used for the front wheels of automobiles, 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 axle.

When the strut assembly rotates with the coil spring due to steering operation, there are two types of suspensions: one in which the piston rod of the assembly rotates, and another in which the piston rod does not rotate, but in both types, the strut assembly rotates with the coil spring. In order to allow the assembly to rotate smoothly, a radial bearing and/or a thrust bearing is required between the mounting member (thrust receiving member) on the vehicle body side and the upper spring seat of the coil spring.

Conventionally, rolling bearings or synthetic resin sliding bearings using balls or needles have been used for bearings in this area, but with the former, there is a risk of damage to the balls or needles due to minute vibrations, vibration loads, etc. Yes, the latter,
In particular, when a strut assembly incorporating a synthetic resin thrust bearing receives an upward load, the thrust bearing placed between the mounting member and the upper spring seat is tightly pressed against the mounting member at its periphery. There is a problem in that uneven contact occurs, which accelerates wear of the relevant parts and deteriorates durability, making it difficult to maintain smooth steering operation.

Here, a conventional strut assembly using a synthetic resin thrust bearing is shown in the drawings as follows.

In FIG. 1, numeral 1 is a shock absorber constituting a strut assembly A, and numeral 2 is its piston rod.

3 is a strut mount insulator, and the insulator 3 is fixed to the vehicle body 4 side.

One end of the piston rod 2 is inserted into the shock absorber 1, and the other end projects from the shock absorber 1 and is fixed to the strut mount insulator 3 with a nut.

Reference numeral 5 denotes a thrust receiving member, and the thrust receiving member 5 is fixed along with the strut mount insulator 3 to the vehicle body 4 at its peripheral edge.

6 is a lower spring seat fixed to the outer cylinder of the shock absorber 1.

Reference numeral 7 denotes an upper spring seat sheet disposed opposite to the lower spring seat sheet 6.

8 is a lower spring seat seat 6 and an upper spring seat seat 7
A coil spring is placed in between.

Reference numeral 9 denotes a synthetic resin thrust bearing disposed between the upper spring seat sheet 7 and the thrust receiving member 5.

B is a dust seal arranged around the outer peripheral surface of the thrust bearing 9.

In the strut assembly A having the above-described configuration, the thrust bearing 9 and the thrust receiving member 5 are in contact with each other over the entire surface when there is no load, that is, in the assembled state.

If the strut assembly receives an upward load (in the axial direction of the piston rod) in this state,
The contact position between the sliding surface of the thrust bearing 9 and the thrust receiving member 5 is shifted toward the outer peripheral edge of the thrust bearing 9, and in extreme cases, the inner peripheral side of the thrust receiving member 5 is shifted upward as shown in FIG. This raises the problem of uneven contact with the outer circumferential edge of the thrust bearing 9, accelerating abrasion of the part, deteriorating durability, and making it difficult to maintain smooth steering operation.

In addition, these bearings are equipped with dust seals to prevent foreign matter such as dust from entering the sliding surfaces, but they are far from perfect, and foreign matter that enters may cause galling. There are also problems such as heavy steering force due to the high frictional force of the rubber elastic body.

The present invention is used in a strut-type suspension in which the piston rod of the strut assembly described above does not rotate due to steering operation.
In particular, this is related to the improvement of the latter bearing mentioned above, which improves the durability of the thrust bearing by preventing the uneven contact phenomenon that occurs in the thrust bearing arranged between the mounting member and the upper spring seat sheet when a load is applied. A dust seal function is added to prevent foreign matter such as dust from entering the sliding surface without using a separate dust seal, and the structure that supports lateral loads ensures smooth steering operation over a long period of time. The technical problem is to obtain a strut thrust bearing that allows for this purpose.

The structure of the present invention, that is, the technical means for solving the above-mentioned technical problems, is as follows. An annular space surrounding the piston rod is formed between a strut mount insulator fixed to the piston rod and to the vehicle body and an upper spring seat of a coil spring loosely inserted into the piston rod. The thrust bearing is arranged in the space, and the thrust bearing consists of a sintered metal inner ring and a synthetic resin outer ring that fits and holds the inner ring, and the inner ring has an insertion hole in its center. , having a tapered surface portion on one end surface and an annular protrusion portion communicating with the insertion hole on the other end surface,
The outer ring has an insertion hole in its center, a flat part on one end face, a tapered face part that matches the tapered face part of the inner ring on the other end face, and a thin cylindrical part and a tapered lip part surrounding the tapered face part. The tapered surface portion of the inner ring is covered by the thin cylindrical portion and the tapered lip portion of the outer ring, and is fitted and held by the outer ring by matching with the tapered lip portion of the outer ring, and the annular protruding portion of the inner ring. A strut thrust bearing is fitted and fixed to the upper spring seat.

In the above configuration, as the sintered metal forming the inner ring, it is particularly preferable to use an oil-impregnated iron-based sintered body, which is an iron-based sintered body impregnated with lubricating oil.

As the synthetic resin forming the outer ring, it is preferable to use polyacetal resin, polyamide resin, or oil-impregnated synthetic resin containing a lubricant in these resins, which have excellent wear resistance and toughness.

Furthermore, in order to further improve the sliding characteristics between the inner ring and the outer ring, a plurality of recesses are formed in a staggered manner in the circumferential direction on the tapered surface of the outer ring that forms the sliding surface, and the recesses are filled with grease, etc. Filling with lubricant is preferred.

The effects of the strut thrust bearing of the present invention having the above-mentioned configuration are as follows.

The tapered surface portions formed on the sintered metal inner ring and the synthetic resin outer ring that constitute the thrust bearing are tapered surface portions each having a downward slope from the inner diameter side to the outer diameter side of the annular body. The assembled thrust bearing always slides and supports the load in the axial direction in a direction perpendicular to the tapered surface.

Therefore, when the thrust bearing is disposed in the annular space formed between the strut mount insulator and the upper spring seat seat, and an upward load (in the axial direction of the piston rod) is applied to the strut assembly. Since the thrust bearing always slides and supports the load on its tapered surface, the inner ring and outer ring are always in sliding contact, and there is no uneven contact between the tapered surfaces, that is, between the sliding surfaces, which improves the durability of the thrust bearing. This improves steering performance and allows smooth steering operation over a long period of time.

In addition, the inner diameter of the tip of the tapered lip formed on the outer diameter side of the synthetic resin outer ring is slightly smaller than the outer diameter of the inner ring, so the inner ring is fitted into the outer ring by expanding the diameter of the tapered lip of the outer ring. Since the tapered lip portion and the outer diameter surface of the inner ring come into close contact with each other, foreign matter such as dust is prevented from entering the sliding surface from there.

Furthermore, since the sliding surfaces of the thrust bearing are tapered surfaces that slide against each other, lateral loads, that is, loads in a direction perpendicular to the axis of the piston rod, can be supported by a wedge action.

This prevents the wheels from wobbling and, in turn, prevents the steering wheel from wobbling.

Hereinafter, embodiments of the technical means of the present invention will be described with reference to FIGS. 3 to 6.

In the figure, 10 is a strut assembly A.
This is the shock absorber that makes up the.

20 is a piston rod of the shock absorber 10, and the piston rod 20 has a small diameter portion 21 formed at its upper end.

30 is a strut mount insulator.

The strut mount insulator 30 includes a cylindrical collar 31, a rubber elastic body 32 integrally formed to cover the outer peripheral surface of the cylindrical collar 31, and a substantially cylindrical portion integrally formed on the outer peripheral surface of the rubber elastic body 32. 3
3, a support member 35 having a wide flange 34 formed on an end surface of the substantially cylindrical portion 33, a rubber elastic body 36 integrally formed to cover the outer peripheral surface of the substantially cylindrical portion 33 of the support member 35, and the rubber. The holding member 39 includes a cylindrical portion 37 integrally formed at the lower peripheral edge of the elastic body 36 and a collar portion 38 .

The mount insulator 30 connects its cylindrical collar 31 to the small diameter portion 21 of the piston rod 20.
The piston rod 20 is fixed to the piston rod 20 by a nut 40, and the wide flange 34 of the support member 35 is fixed to a mounting member 50 of the vehicle body.

60 is an upper spring seat sheet, and the upper spring seat sheet 60 has an annular recess 61 formed in its center, and a circular hole 62 in the annular recess 61.
is formed.

The upper spring seat sheet 60 has the peripheral edge of the annular recess 61 facing the holding member 39 of the strut mount insulator 30, and the annular recess 61 of the upper spring seat sheet 60 and the holding member 39 The cylindrical portion 37 and the collar portion 38 form an annular space S there.

Reference numeral 70 denotes a lower spring seat sheet, which is disposed opposite to the upper spring seat sheet 60 and is fixed to the outer cylinder of the shock absorber 10.

80 is a coil spring disposed between the upper spring seat sheet 60 and the lower spring seat sheet 70.

Reference numeral 90 denotes a thrust bearing arranged in the annular space S, and the thrust bearing 90 is composed of an inner ring 91 made of sintered metal and an outer ring 92 made of synthetic resin that fits and holds the inner ring 91.

The inner ring 91 has an insertion hole 911 in its center, and has a tapered surface part 912 on one end surface thereof having a downward slope from the inner diameter side to the outer diameter side.
is formed, and the insertion hole 91 is formed on the other end surface.
An annular protrusion 913 communicating with 1 is formed.

On the other hand, the outer ring 92 has an insertion hole 921 in its center.
and has a flat part 9 on one end surface.
22, a tapered surface portion 923 that matches the tapered surface portion 912 of the inner ring 91 is formed on the other end surface, a thin cylindrical portion 924 is formed on the inner diameter side, and a thin cylindrical portion 924 is tapered in the axial direction on the outer diameter side. Thin tapered lip portions 925 are formed surrounding the tapered surface portions 923, respectively.

The inner diameter of the tip of the thin tapered lip portion 925 is slightly smaller than the outer diameter of the inner ring 91.

Reference numeral 926 denotes a plurality of recesses formed in the tapered surface portion 923 of the outer ring 92, and the recesses 926 are formed in a staggered manner in the circumferential direction of the tapered surface portion 923.

The recess 926 serves as a reservoir for lubricant such as grease.

The thrust bearing 90 having the above configuration has an outer ring 92
After applying a lubricant such as grease to the plurality of recesses 926 formed in the tapered surface portion 923 of the inner ring 91, the inner ring 91 is attached to the tapered lip portion 92 of the outer ring 92
5 is expanded in diameter and fitted onto the outer ring 92, and the tapered surface portions 912 and 923 are matched, and the inner ring 91
is connected to the thin cylindrical portion 924 of the outer ring 92 on the inner diameter side,
The outer diameter side thereof is covered with a thin tapered lip 925 and assembled.

The thrust bearing 90 assembled in this manner is fitted and fixed at the annular protrusion 913 of the inner ring 91 into the circular hole 62 of the upper spring seat sheet 60, and is also connected to the annular recess 61 of the upper spring seat sheet 60 and the strut mount inlet. It is disposed in an annular space S formed by the cylindrical portion 37 and the collar portion 38 of the holding member 39 of the oscillator 30 .

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional strut assembly, Fig. 2 is a partially enlarged sectional view showing a loaded state, and Fig. 3 is a sectional view showing a strut assembly using the strut thrust bearing of the present invention. , FIG. 4 is a sectional view showing the strut thrust bearing, FIG. 5 is a partially enlarged sectional view of the outer ring of the strut thrust bearing, and FIG. 6 is a view taken along the line X--X in FIG. 5. 10...Shock absorber, 20...Piston rod, 30...Strut mount insulator, 60...Upper spring seat, 70...Lower spring seat, 80...Coil spring, 90...
Thrust bearing, 91... Inner ring, 93... Outer ring, S
...Space department.

Claims (1)

[Scope of utility model registration request] An annular space surrounding the piston rod is formed between a strut mount insulator fixed to the piston rod and to the vehicle body and an upper spring seat of a coil spring loosely inserted into the piston rod. The thrust bearing is arranged in the space, and the thrust bearing consists of a sintered metal inner ring and a synthetic resin outer ring that fits and holds the inner ring, and the inner ring has an insertion hole in its center. , has a tapered surface portion on one end surface and an annular protrusion portion communicating with the insertion hole on the other surface, the outer ring has an insertion hole in the center thereof, and a flat portion on one end surface, The other end surface has a tapered surface portion that matches the tapered surface portion of the inner ring, a thin cylindrical portion surrounding the tapered surface portion, and a tapered lip portion. A strut thrust bearing, which is covered by the above-mentioned ring, is fitted and held in the outer ring so as to match the tapered surface of the outer ring, and is fitted and fixed to the upper spring seat at the annular protrusion of the inner ring.