JPH0627863Y2 - Bush assembly - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is characterized in that a sliding member is interposed between a first tubular body and a second tubular body, and the sliding member slides the first The present invention relates to a bush assembly that allows relative rotation of a tubular body and a second tubular body. INDUSTRIAL APPLICABILITY The bush assembly of the present invention can be applied to mounting a suspension arm or the like.

[Prior Art] Conventionally, as shown in FIG. 6, an inner cylinder 100 and an inner cylinder 1 are provided.
00, an outer cylinder 200 arranged concentrically, and an intermediate cylinder 300 arranged concentrically between the inner cylinder 100 and the outer cylinder 200.
An elastic member 400 interposed between the intermediate cylinder 300 and the outer cylinder 200, and a sliding member 500 interposed between the inner cylinder 100 and the intermediate cylinder 300 and fitted and fixed to the intermediate cylinder 300 by press fitting. There is known a bush assembly having a stopper fitting 600 fixed by press fitting to the outer peripheral surface of the inner cylinder 100 axially outward of the sliding member 500 (Japanese Patent Laid-Open No. 64-64-
6441).

In the bush assembly, the elastic member 400 interposed between the outer cylinder 200 and the intermediate cylinder 300 absorbs the relative vibration of the inner cylinder 100 and the outer cylinder 200 in the direction intersecting with the axial direction, and also the inner cylinder 100. When the sliding member 500 slides with the boundary surface between the outer peripheral surface of the inner cylinder 100 and the inner peripheral surface of the sliding member 500 as a sliding surface, a torsion spring action due to relative rotation between the inner cylinder 100 and the outer cylinder 200 is achieved. It is decreasing.

[Problems to be Solved by the Invention] However, the above-mentioned conventional bush assembly has the inner cylinder 100,
The intermediate cylinder 300 and the sliding member 500 are each manufactured to have a predetermined size, and after the sliding member 500 is press-fitted and fixed to the intermediate cylinder 300, a fixed sliding clearance is provided between the sliding member 500 and the inner cylinder 100. It is manufactured by fitting the intermediate cylinder 300 and the sliding member 500 to the inner cylinder 100 so that Then, the inner peripheral surface of the sliding member 500 and the inner cylinder 10
The sliding member 50 uses the boundary surface between the outer peripheral surface of 0 and the outer peripheral surface as a sliding surface.
0 is slidable with respect to the inner cylinder 100. Therefore, variations in sliding clearances in the radial direction and the axial direction due to manufacturing errors of the respective members, and thus rattling in the radial direction and the axial direction are likely to occur. Further, in order to prevent the rattling, it is necessary to improve the dimensional accuracy of each member by cutting or the like, which leads to an increase in the number of steps and an increase in cost.

Further, since a large number of constituent parts are required, such as a stopper fitting 600 for preventing the sliding member 500 from being pulled out in the axial direction, the number of assembling steps is large and the cost is high.

An object of the present invention is to provide a bush assembly which can secure a stable sliding clearance and is easy to assemble, and which is a technical problem to be solved.

[Means for Solving the Problems] A bush assembly according to the present invention is arranged concentrically with a first tubular body at a predetermined interval on the outer periphery of the first tubular body and has an inner peripheral surface on the inner circumferential surface thereof. Is provided so as to cover the entire outer peripheral surface of the first cylindrical body and the second cylindrical body provided with the convex or concave axial direction restricting portion extending in the circumferential direction, and the first cylindrical body Between the first tubular body and the second tubular body, the first tubular body being formed by injection molding within a range that exceeds at least the axial width of the axial direction regulating portion on both sides. A tubular resin sliding member fixed to the second tubular body and having a sliding clearance formed between the tubular tubular member and the second tubular body; It is characterized in that it comprises a pair of seal members which are in close contact with the resin-made sliding member on the outer peripheral surface of the first tubular shape and seal the same.

It is preferable to provide one or more annular recesses or annular projections extending in the circumferential direction on the outer peripheral surface of the first tubular body. The annular concave portion or the annular convex portion can increase the axial coupling force of the resin sliding member with respect to the first cylindrical body.

The second tubular body is concentrically arranged on the outer periphery of the first tubular body at a predetermined interval. A convex or concave axial restriction portion extending in the circumferential direction is provided on the inner peripheral surface of the second tubular body. The axial restricting portion is for restricting the second tubular body and the resin sliding member in the axial direction. The convex axial restricting portion may be provided integrally with the second tubular body by pressing the second tubular body, or at a predetermined position on the inner peripheral surface of the second tubular body. It may be provided by fitting and fixing another tubular body. On the other hand, the concave axial restricting portion is the second
It can be provided in a groove shape on the inner peripheral surface of the tubular body by cutting or the like. When the two convex axial regulation portions are provided, one concave axial regulation portion is provided between the respective axial regulation portions. The second tubular body is coaxially butted to the second tubular body.
It can also be composed of one divided tubular body.

The resin sliding member is provided so as to cover the entire outer peripheral surface of the first tubular body, and at least the second tubular body is provided between the first tubular body and the second tubular body. Is formed by injection molding within a range that exceeds the axial width of the axial direction restricting portion on both sides. After injection molding of the resin sliding member,
When the resin cools, the resin sliding member mainly contracts inward in the radial direction and is firmly fixed to the first tubular body, and at the same time, an appropriate sliding clearance is formed between the resin sliding member and the second tubular body. It is formed.

[Operation] The bush assembly according to the present invention is formed by injection molding within a range in which the axial width of at least the convex or concave axial restriction portion between the first cylindrical body and the second cylindrical body exceeds both sides. The formed resin sliding member is firmly fixed to the first cylindrical body mainly by the contraction force of the resin after the injection molding inward in the radial direction, and the sliding member is formed between the second cylindrical body and the second cylindrical body. Stable sliding clearance is secured.

Therefore, stable relative rotation is possible between the first tubular body and the second tubular body via the resin sliding member. Further, the resin sliding member is firmly fixed to the first cylindrical body by utilizing the contracting force of the resin, and the axial direction restricting portion of the second cylindrical body prevents unnecessary axial movement. It is regulated, and the first tubular body, the resin sliding member, and the second tubular body are reliably coupled in the radial direction and the axial direction.

Further, at the same time when the sliding clearance is formed, the resin sliding member is formed over the entire outer peripheral surface of the first tubular body including the sliding contact portion with the seal member. High rust resistance at both ends of the outer peripheral surface is obtained,
Smoothness is ensured at the sliding contact portion with the seal member.

[Embodiment] Hereinafter, a bush assembly of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a vertical sectional view of the bush assembly of this embodiment. The bush assembly of this embodiment has an inner cylinder (first cylindrical body).
1, an outer cylinder 2 arranged concentrically with the inner cylinder 1, and an inner intermediate cylinder (second part) concentrically arranged between the inner cylinder 1 and the outer cylinder 2.
(Cylindrical body) 3 and outer intermediate cylinder 4, elastic member 5 interposed between outer intermediate cylinder 4 and outer cylinder 2, and resin sliding member interposed between inner cylinder 1 and inner intermediate cylinder 3. The moving member 6 and the seal member 7 interposed between the inner peripheral surface of both ends of the outer intermediate cylinder 4 and the outer peripheral surface of the sliding member 6 fixed near both ends of the inner cylinder 1 are the main constituent elements. There is.

The inner cylinder 1 is a cylindrical body made of metal. Inner cylinder 1
Three annular recesses 11 extending in the circumferential direction are formed at a predetermined interval on the outer peripheral surface of the.

The outer cylinder 2 is a cylindrical body made of metal, and has a bulging portion 21 that projects radially outward at one end side.

The inner intermediate cylinder 3 is a cylindrical body made of metal, and is concentrically arranged on the outer periphery of the inner cylinder 1 at a predetermined interval. The inner peripheral surface of the inner intermediate cylinder 3 has a ring-like shape 2 made of metal.
The individual axial regulating members 31, 31 are fitted and fixed by press fitting at a predetermined interval in the axial direction.

The inner intermediate cylinder 3 may be composed of two split cylindrical bodies that are coaxially butted together. For example, as shown in FIG. 4, two semi-inner intermediate cylinders 302, 302 each having a convex portion 301 formed by press work so as to project inward in the radial direction in an annular shape extending in the circumferential direction are provided with an outer intermediate portion. Tube 4
It is possible to use the one that is fitted and fixed by press fitting. Further, as shown in FIG. 5, two semi-intermediate cylinders 31 each having an annular convex portion 311 integrally formed on the inner peripheral surface thereof.
It is also possible to fix 0 and 310 at the abutting ends with an adhesive or the like for use. In this case, the outer intermediate cylinder 4 is not particularly required.

The outer intermediate cylinder 4 is made of metal and is a cylindrical body that is longer than the inner intermediate cylinder 3 in the axial direction. The inner intermediate cylinder 3 is fitted and fixed in the outer intermediate cylinder 4 by press fitting.

The elastic member 5 is made of a rubber elastic body, is molded and vulcanized between the inner peripheral surface of the outer cylinder 2 and the outer peripheral surface of the outer intermediate cylinder 4, and is vulcanized and bonded to the outer cylinder 2 and the outer intermediate cylinder 4. .

The resin sliding member 6 is made of oil-impregnated plastic having good slidability and is provided between the inner cylinder 1 and the inner intermediate cylinder 3 between the two axial direction regulating members 31, 31 and between the inner cylinder 1 and each axial direction. Restriction member 31,
It is formed by injection molding the outer peripheral surfaces of both ends of the inner cylinder 1 positioned between the inner cylinder 1 and the axial direction restricting members 31, 31. Then, 0.1 m is provided between the sliding member 6, the inner intermediate cylinder 3 and the axial direction regulating members 31, 31.
The sliding clearance is secured so that it does not exceed m.

The seal member 7 is a ring-shaped member made of rubber, and a metal ring 71 having an L-shaped cross section is buried in the outer peripheral surface of the seal member 7 and is fitted into both inner peripheral surfaces of both ends of the outer intermediate cylinder 4 by press fitting. A pleated seal portion 72 is formed on the inner peripheral surface of the seal member 7.
Are formed, and are in sliding contact with the outer peripheral surface of the sliding member 6 fixed to the outer peripheral surfaces near both ends of the inner cylinder 1, respectively.

The bush assembly of the present embodiment having the above structure was manufactured as follows.

First, as shown in FIG. 2, while the outer cylinder 2 and the outer middle cylinder 4 are arranged concentrically, the elastic member 5 is molded and vulcanized, and the outer cylinder 2 and the outer middle cylinder 4 are vulcanized and bonded. Due to
The outer cylinder 2, the outer intermediate cylinder 4, and the elastic member 5 are integrated.
Next, as shown in FIG. 3, the inner intermediate cylinder 3 and the inner cylinder 1 in which two axial direction restricting members 31, 31 are fitted and fixed by press fitting at a predetermined position on the inner peripheral surface are arranged concentrically. Set in a mold with a predetermined shape in this state, inject the oil-containing plastic into the mold,
The sliding member 6 is cooled. The sliding member 6 and the inner cylinder 1
An adhesive may be applied in advance to the outer peripheral surface of the inner cylinder 1 in order to further strengthen the binding force with. Further, in order to obtain smoother slidability, grease or the like should be applied in advance to the inner peripheral surface of the inner intermediate cylinder 3 with which the sliding member 6 slides and the inner peripheral surfaces of the axial direction regulating members 31, 31. You can also During the cooling process, the oil-containing plastic mainly shrinks inward in the radial direction, and the contracting force securely fixes the sliding member 6 to the inner cylinder 1 and the inner intermediate cylinder 3 and each axial direction regulating member 31,
A proper sliding clearance is secured between the member 31 and the member 31. Then, the inner cylinder 1, the inner intermediate cylinder 3, and the sliding member 6 are provided in a unitary body including the outer cylinder 2, the outer intermediate cylinder 4, and the elastic member 5.
The one body consisting of is fitted and fixed by press fitting, and further the inner cylinder 1
The bush members of this embodiment were obtained by fitting the seal members 7 and 7 to both ends of each by press fitting.

In the bush assembly of this embodiment, when an external force in the radial direction acts between the inner cylinder 1 and the outer cylinder 2, the elastic member 5 correspondingly compresses and deforms in the radial direction to exert a cushioning effect. On the other hand, when an external force that relatively rotates the inner cylinder 1 and the outer cylinder 2 acts,
Although the elastic member 5 elastically deforms in the circumferential direction to exert a cushioning effect,
At this time, the sliding member 6 rotates with a sliding resistance between the inner intermediate cylinder 3 and the axial direction restricting members 31, 31, so that elastic deformation of the elastic member 5 is reduced and the cushioning action is moderate. Can be

Further, in the bush assembly of the present embodiment, the resin sliding member 6 formed by injection molding between the inner cylinder 1, the inner intermediate cylinder 3, and the axial direction regulating members 31, 31 has a structure after the injection molding. The resin is firmly fixed to the inner cylinder 1 mainly by the inward contracting force in the radial direction, and a stable sliding clearance is secured between the inner intermediate cylinder 3 and the axial direction regulating members 31, 31. There is. Therefore, stable relative rotation can be performed between the inner cylinder 1 and the inner intermediate cylinder 3 via the resin sliding member 6, and the above-mentioned cushioning effect can be reliably achieved.

Further, after injection molding, a sliding clearance is formed between the sliding member 6 and the inner intermediate cylinder 3 and the axial direction regulating members 31, 31 by utilizing the contracting force of the resin when the resin is cooled. Therefore, the sliding clearances in the axial direction and the radial direction can always be kept at a substantially constant value without the need to process each of the above-described members with high accuracy as in the conventional case, and the cost can be reduced. The stability of the above-mentioned cushioning action can be improved.

Further, the sliding member 6 is integrally formed with the inner cylinder 1 and the inner intermediate cylinder 3 by injection molding. An annular recess 11 is formed on the outer peripheral surface of the inner cylinder 1, and the sliding member 6 is fixed so as to be embedded in the annular recess 11. Further, the sliding member 6 is reliably regulated by the axial regulation members 31, 31 of the inner intermediate cylinder 3 so as to prevent excessive movement in the axial direction. The two axial regulation members 31, 31 act as two convex axial regulation portions, and each axial regulation member 3
It also acts as one concave axial restriction portion formed between the first and the third portions. Therefore, the stopper fitting for preventing the sliding member 6 from pulling out in the axial direction is unnecessary. Further, the step of press-fitting the sliding member 6 and the step of press-fitting the stopper fittings are not required, and the number of assembling steps can be reduced.

Furthermore, since the sliding member 6 is formed up to the outer peripheral surface end of the inner cylinder 1 with which the seal member 71 of the seal member 7 slidably contacts, the outer peripheral surface end of the inner cylinder 1 has high rust prevention and smoothness. Can be secured.

Further, as described above, since a stopper fitting is not required unlike the conventional bush assembly, the rotational speed of the seal surface with which the seal member 7 is in sliding contact is reduced. That is, the above-mentioned sealing surface in the conventional bush assembly is a surface that rotates with the total length of the outer diameter of the inner cylinder and the radial width of the stopper metal fitting as the moving radius, whereas the bush assembly of the present embodiment. The above-mentioned sealing surface is a surface that rotates with the total length of the outer diameter of the inner cylinder 1 and the radial width of the sliding member 6 at the portion where the sealing member 7 is in sliding contact as the moving radius. Therefore, in the bush assembly of the present embodiment, the above-mentioned moving radius is smaller than that of the conventional one, and the rotation speed of the sealing surface is reduced accordingly. Therefore, the frictional resistance on the seal surface is reduced, and the amount of wear of the seal member 7 can be reduced.

[Effect of the Invention] As described in detail above, the bush assembly of the present invention is
The resin is formed between the tubular body and the second tubular body by injection molding at least within a range that exceeds the axial width of the axial direction restricting portion on both sides, and the shrinkage force of the resin after the injection molding is used to make the resin The manufactured sliding member is firmly fixed to the first tubular body, and a stable sliding clearance is secured between the sliding member and the second tubular body.

Therefore, the sliding clearance can always be set to a substantially constant value. Therefore, the stability of the cushioning action due to sliding can be improved, and it is not necessary to precisely process each member by cutting or the like. It is possible to reduce the cost and cost.

The resin sliding member is integrally formed with the first tubular body and the second tubular body by injection molding. The resin sliding member is firmly fixed to the first tubular body, and the axial regulation portion of the second tubular body reliably regulates excessive axial movement. For this reason, the stopper fitting for preventing the sliding member from being pulled out in the axial direction, which is required in the conventional bush assembly, is not required. Further, the step of press-fitting the sliding member and the stopper fitting is unnecessary, and the number of assembling steps can be reduced.

Further, since the resin sliding member is formed over the entire outer peripheral surface of the first tubular body including the sliding contact portion with the seal member, high rust resistance at both ends of the outer peripheral surface of the first tubular body is provided. Since the smoothness is ensured in the sliding contact portion with the seal member, it is not necessary to newly apply rust prevention treatment or surface polishing processing to both end portions of the outer peripheral surface of the first tubular body, and the seal member It is possible to reduce the amount of wear of the seal member by reducing the sliding resistance between the sliding member made of resin and the sliding member made of resin.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a bush assembly according to an embodiment of the present invention, and FIG. 2 is an outer cylinder of the bush assembly, an elastic member,
FIG. 4 is a vertical cross-sectional view showing a state in which the inner intermediate cylinder, the sliding member, and the inner cylinder of the bush assembly are integrally formed. The figure is a longitudinal sectional view showing another embodiment of the inner intermediate cylinder,
FIG. 6 is a vertical cross-sectional view showing still another mode of the inner intermediate cylinder, and FIG. 6 is a vertical cross-sectional view of a conventional bush assembly. 1 ... Inner tube (first tubular body), 2 ... Outer tube 3 ... Inner intermediate tube (second tubular body) 4, Outer intermediate tube, 5 ... Elastic member 6 ... Resin sliding Member, 7 ... Seal member 31 ... Axial direction regulating member

Claims (1)

[Scope of utility model registration request] 1. A first cylindrical body and a concentric shaft which is concentrically arranged on the outer periphery of the first cylindrical body at a predetermined distance from each other and extends in the circumferential direction on its inner peripheral surface. A second tubular body provided with a direction regulating portion, and provided so as to cover the entire outer peripheral surface of the first tubular body,
It is formed by injection molding between the first tubular body and the second tubular body at least within a range that exceeds the axial width of the axial direction restricting portion on both sides, and by the contraction force of the resin after the injection molding. A tubular resin sliding member fixed to the first tubular body and having a sliding clearance formed between the first tubular body and the second tubular body, and on both outer sides in the axial direction of the axial direction restricting portion. A bushing assembly, the inner peripheral surface of which comprises a pair of sealing members which are in close contact with the resin sliding member on the outer peripheral surface of the first tubular member to seal the resin sliding member.