JP2013167307A - Bushing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bushing which can secure performance of the bushing and can reduce its weight and cost.SOLUTION: A front bushing 20 is housed within a holder opening 19 of a holder 17 and thus a support collar 25 is supported by the holder 17. The bushing 10 is provided with a base material 27 capable of coupling to outer periphery 25a of the support collar 25 and a surface layer 31 integrally formed on outer periphery 27a of holder opening 19 side among the base material 27. The size of the surface layer 31 is formed in thin wall-like manner by an elastic material having self-adhesion so as to become smaller than size in thickness T2 of the base material 27.

Description

  The present invention relates to a bush for elastically coupling a holder and a support object by being housed in an opening of a holder formed separately.

Among bushes used for automobile suspension links, etc., a cylindrical anti-vibration rubber body is provided on the outer peripheral wall of the inner cylinder, and a cylindrical collar is press-fitted into the outer periphery of the anti-vibration rubber body, and then the collar is press-fitted into the holder. It has been known.
With the collar press-fitted into the holder, the holder is connected to the suspension arm, and the inner cylinder is connected to the vehicle body, whereby the suspension arm is connected to the vehicle body via the bush.
According to this bush, by press-fitting the collar into the holder, the collar (that is, the bush) can be prevented from slipping with respect to the holder, and the performance of the bush can be ensured (see, for example, Patent Document 1).

  However, a metal collar is used for the bush of Patent Document 1. For this reason, the weight of the bush is increased by providing the bush with a collar, and there remains room for improvement from this viewpoint.

  Moreover, in the bush, a resin adhesive is applied to the inner and outer peripheral surfaces of the vibration isolating rubber main body, and the vibration isolating rubber main body coated with the adhesive is press-fitted into the gap between the inner cylinder and the outer cylinder, An adhesive layer is known by curing an adhesive after press-fitting a vibration-proof rubber body (see, for example, Patent Document 2).

No. 2-9144 JP 2006-220189 A

However, the bush of Patent Document 2 is required to suppress peeling due to the load of the adhesive layer and aging degradation. For this reason, it is necessary to use a special adhesive suitable for cross-linking with the anti-vibration rubber body and match it with the vulcanization of the anti-vibration rubber body. Furthermore, it is necessary to perform heat treatment and chemical treatment during bonding. is there.
In addition, pre-processing such as coating a metal inner cylinder or outer cylinder may be necessary during bonding, which has hindered cost reduction.

  In addition, it is possible to integrate the holder and the bush by integral vulcanization molding, but the cost similarly increases. In addition, when the holder is made of a resin material such as fiber reinforced resin or engineering plastic, it may be difficult to adopt the vulcanization molding itself, and further improvement is required.

  An object of this invention is to provide the bush which can ensure the performance of a bush and can aim at weight reduction and cost reduction.

  The invention which concerns on Claim 1 is a bush by which a support part is supported by the said holder by being accommodated in the opening part of a holder, Comprising: Of the base material which can be couple | bonded with the outer periphery of the said support part, and the said base material And a surface layer integrally formed on the outer periphery of the opening portion side so as to be thinner than a thickness of the base material by a self-adhesive elastic material.

  According to a second aspect of the present invention, a recessed portion is formed on the inner diameter side from the opening of the base material, and the surface layer of a portion corresponding to the recessed portion is formed thick.

  According to a third aspect of the present invention, an annular groove is formed in the opening of the holder, and the surface layer of a portion corresponding to the groove is formed thick toward the outer periphery.

  According to a fourth aspect of the present invention, the axial end of the surface layer is covered with the base material.

  According to a fifth aspect of the present invention, a protruding portion is protruded from a part of the base material toward the surface layer.

In the invention which concerns on Claim 1, a surface layer can be firmly stuck to the opening part of a holder by having self-adhesiveness in a surface layer.
Here, the self-adhesive property is a property in which the elastic material itself is fluidly deformed so as to fill a gap by changing the bonding state of the molecular arms of the elastic material (also called self-bonding property). In general, since such an elastic material adapts to the member with which the surface shape abuts, it exhibits extremely strong adhesive force.
Therefore, by using a self-adhesive elastic material for the surface layer, it is possible to suppress the slip between the opening and the surface layer in a state where the surface layer is fitted in the opening of the holder.
Thereby, it can prevent with a surface layer that sliding arises with respect to the opening part of a holder.

Further, the surface layer was formed thinner than the thickness of the substrate. Therefore, it becomes possible to exhibit the original spring characteristics of the substrate without being affected by the surface layer, and the spring characteristics of the substrate can be easily adjusted.
Thus, the bush performance can be sufficiently secured by preventing the holder from sliding with respect to the opening and making the spring characteristics of the base material adjustable.

Further, by interposing a self-adhesive surface layer between the base material and the opening of the holder and closely contacting the opening and the surface layer of the holder, a metal collar is interposed between the base and the opening of the holder. There is no need.
Thereby, since the metal collar can be removed from the bush, the weight of the bush can be reduced.

In addition, by forming the self-adhesive surface layer integrally with the outer periphery of the base material, it is necessary to attach the base material to the opening of the holder with an adhesive. There is no need to consider the affinity of the adhesive to the cylinder.
Thereby, the freedom degree at the time of selecting the raw material for holders and the elastic material for surface layers can be raised, and cost reduction can be aimed at.

  In the invention which concerns on Claim 2, the surface layer is shape | molded by forming the recessed part from the opening part of the said base material to an internal-diameter side, and forming the surface layer of the site | part corresponding to this recessed part thickly. Even when the material (elastic material) is highly viscous, the material can be satisfactorily filled in the axial direction and circumferential direction of the gap through the recessed portion, so that the surface layer can be formed into a more uniform thin wall.

  In the invention according to claim 3, by bulging the thick portion of the surface layer into the groove portion, it is possible to prevent the surface layer from slipping out of the opening at the thick portion, and to suppress displacement of the surface layer in the axial direction. .

In the invention which concerns on Claim 4, it can suppress that a surface layer is displaced to an axial direction or flows by covering the axial direction edge part of a surface layer with a base material.
Thereby, since the abrasion of the surface which contacts an opening part among surface layers can be suppressed, durability of a bush can be improved.

Moreover, the surface layer can be kept in a predetermined shape by suppressing the displacement and flow of the surface layer in the axial direction with the base material.
Therefore, the characteristics (self-adhesiveness, adhesiveness) of the surface layer can be suitably exhibited. Thereby, the sealing property of the opening part of a holder and a surface layer etc. can be improved.

In the invention which concerns on Claim 5, a surface layer can be divided | segmented on the boundary of a protrusion part by making a protrusion part protrude toward a surface layer from a part of base material.
Thereby, the stress (load) generated in the surface layer can be dispersed in the divided surface layers to suppress the deformation of the surface layer.
In addition, by dividing the surface layer with the protruding portion as a boundary, displacement and flow in the axial direction of the surface layer can be suppressed by the protruding portion. Thereby, the surface layer can be kept in a predetermined position or in a predetermined shape.

It is a perspective view showing a vehicle provided with a bush of Example 1 concerning the present invention. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. It is a side view which shows the bush of Example 2 which concerns on this invention. FIG. 5 is a sectional view taken along line 5-5 of FIG. FIG. 6 is a sectional view taken along line 6-6 of FIG. It is sectional drawing which shows the bush of Example 3 which concerns on this invention. It is sectional drawing which shows the bush of Example 4 which concerns on this invention. It is sectional drawing which shows the bush of Example 5 which concerns on this invention.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. Note that “front (Fr)”, “rear (Rr)”, “left (L)”, and “right (R)” follow the direction seen from the driver.

The bush according to the first embodiment will be described.
As shown in FIG. 1, the vehicle 10 includes a sub frame 12 provided on the lower side of the body frame and a suspension arm 16 provided on the sub frame 12 so as to be swingable.

The subframe 12 is a frame that can support a power unit (not shown) in which an engine and a transmission are integrated.
In this subframe 12, a front bush (bush) 20 is rotatably supported by a bolt 23 on the front bracket 13, and a rear bush (bush) 21 is rotatably supported by a bolt 24 on the rear bracket 14.

The front bush 20 is press-fitted into a front holder (holder) 17 of the suspension arm 16. The front holder 17 is provided at the tip of the front arm 16 a of the suspension arm 16.
The rear bush 21 is press-fitted into a rear holder (holder) 18 of the suspension arm 16. The rear holder 18 is provided at the tip of the rear arm 16 b of the suspension arm 16.
Here, the front bush 20 and the rear bush 21 are similar members. Hereinafter, the front bush 20 will be described and description of the rear bush 21 will be omitted.

  As shown in FIGS. 2 and 3, the front bush 20 includes a support collar (support portion) 25 that can be fitted into the bolt 23, a base material 27 provided on an outer periphery 25 a of the support collar 25, and an outer periphery of the base material 27. 27a, and a surface layer 31 provided on 27a.

The support collar 25 is formed in a cylindrical shape so that the bolt 23 can be inserted into the hollow portion 26.
By inserting the bolt 23 into the pair of support holes 13 a of the front bracket 13 and further inserting the bolt 23 into the hollow portion 26 of the support collar 25, the support collar 25 is rotatably supported by the front bracket 13 via the bolt 23. ing.
A base material 27 is provided on the outer periphery 25 a of the support collar 25.

The base material 27 is formed in a cylindrical shape with natural rubber (NR), and thus the base material opening portion 28 penetrating in the center and the circular shape coaxially with the base material opening portion 28 are formed. And an outer periphery 27a.
By integrally vulcanizing the base material 27, the base material 27 (base material opening portion 28) is coupled to the outer periphery 25 a of the support collar 25 in a state where the support collar 25 is inserted into the base material opening portion 28. .
An outer periphery 27 a of the base material 27 is formed in a circular shape on the holder opening (opening) 19 side formed in the front holder 17.

The natural rubber forming the base material 27 can elastically deform the base material 27 when a load is input from the support collar 25 or the front holder 17, and can recover the elastic deformation when the load is removed from the base material 27. Spring characteristics.
A surface layer 31 is integrally formed on the outer periphery 27a of the base material 27 by two-color molding.

The surface layer 31 is an annular thin member integrally formed with a self-adhesive elastic material on the outer periphery 27 a of the base material 27.
The surface layer 31 is formed in a thin shape so that the thickness dimension T1 is smaller than the thickness dimension (thickness) T2 of the base material 27.
For example, butyl rubber (IIR) is used as the self-adhesive elastic material.

As an example, the thickness T1 of the surface layer 31 is set to 1.0 to 2.0 mm.
The reason why the thickness T1 of the surface layer 31 is set to 1.0 to 2.0 mm is as follows.
That is, when the thickness T1 of the surface layer 31 is less than 1.0 mm, it is difficult to suitably fill the cavity of the mold with butyl rubber when the surface layer 31 is two-color molded.

On the other hand, when the thickness T1 of the surface layer 31 exceeds 2.0 mm, the thickness of the surface layer 31 becomes too thick and the influence of the characteristics of the surface layer 31 increases.
Therefore, the thickness T1 of the surface layer 31 is set to 1.0 to 2.0 mm to improve the sealing performance between the holder opening 19 and the surface layer 31, and the spring characteristics of the base material 27 are improved. 31 was not affected.
By making the spring characteristics of the base material 27 unaffected by the surface layer 31, the spring characteristics of the base material 27 (that is, the front bush 20) can be easily adjusted.

The front bushing 20 is formed by integrally molding the surface layer 31 on the outer periphery 27a of the base material 27 by two-color molding. The front bush 20 is attached to the front holder 17 by being press-fitted (accommodated) into the holder opening 19 of the front holder 17.
As a result, the support collar 25 is supported coaxially by the front holder 17 via the base material 27 and the surface layer 31.

Here, since the surface layer 31 has self-adhesiveness, the surface layer 31 can be firmly adhered to the holder opening 19.
Therefore, the slip between the holder opening 19 and the surface layer 31 can be suppressed and brought into close contact with the surface layer 31 fitted into the holder opening 19.

As a result, it is possible to suppress wear on the outer periphery 31 a of the surface layer 31 that contacts the holder opening 19 by suppressing the base material 27 from slipping with respect to the holder opening 19 by the surface layer 31.
As described above, the spring characteristics of the base member 27 (that is, the front bush 20) can be adjusted, and the base member 27 can be prevented from slipping with respect to the holder opening 19, thereby sufficiently improving the performance of the front bush 20. It can be secured.

Furthermore, a self-adhesive surface layer 31 is interposed between the base material 27 and the holder opening 19 to bring the holder opening 19 and the surface layer 31 into close contact with each other. There is no need to intervene color.
Thereby, since the metal collar can be removed from the front bush 20, the weight of the front bush 20 can be reduced.

In addition, by forming the self-adhesive surface layer 31 integrally with the outer periphery of the base material 27, a metal or resin that is required when the base material 27 is bonded to the holder opening 19 with an adhesive. There is no need to consider the affinity of the adhesive to the inner and outer cylinders.
Thereby, the freedom degree at the time of selecting the raw material for the front holder 17 and the elastic material for the surface layer 31 can be raised, and cost reduction can be aimed at.

  Next, bushings of Examples 2 to 5 will be described with reference to FIGS. In addition, in the bush of Example 2-Example 5, the same code | symbol is attached | subjected about the same similar member as the front bush 20 of Example 1, and description is abbreviate | omitted.

The front bush (bush) 40 according to the second embodiment will be described.
As shown in FIGS. 4 to 6, the front bush 40 is obtained by replacing the surface layer 31 of the first embodiment with the surface layer 41, and other configurations are the same as those of the front bush 20 of the first embodiment.
In the front bush 40, a surface layer 41 is integrally formed on the outer periphery of the base material 27 using a recessed portion 48 formed in the base material 27.

The holder 45 has an annular groove 46 formed in the holder opening 19.
The annular groove 46 is formed in an annular shape in the holder opening 19 at substantially the center in the axial direction of the support collar 25.

Thereby, even when the material (elastic material) for forming the surface layer 41 has a high viscosity, the injected material is injected into the groove portion 46 from the recessed portion 48, whereby the injected material is passed through the recessed portion 48. Good filling in the axial and circumferential directions.
Therefore, as shown in FIGS. 4 and 5, the surface layer 41 can be formed into a more uniform thin shape.

As shown in FIGS. 4 and 5, the surface layer 41 is formed thick by the thick portion 42 bulging toward the outer side in the radial direction of the surface layer 41 at a portion corresponding to the groove portion 46 in the outer periphery 41 a. Has been.
In this way, by bulging the thick portion 42 of the surface layer 41 into the groove portion 46, the thick portion 42 can prevent the surface layer 41 from slipping out of the holder opening 19, and the axial direction of the surface layer 41 can be prevented. The displacement to can be suppressed.

The front bush (bush) 50 according to the third embodiment will be described.
As shown in FIG. 7, the front bush 50 is configured so as to cover both axial end portions (axial end portions) 51 a and 51 b of the surface layer 51 with the base material 54, and the other configurations are the same as those in the first embodiment. Similar to the front bush 20.

The base 54 projects one overhang 55 from one end 54 b of the outer periphery 54 a toward the holder opening 19, and the other overhang 56 from the other end 54 c of the outer periphery 54 a toward the holder opening 19. The other configuration is the same as that of the base material 27 of the first embodiment.
One overhang portion 55 and the other overhang portion 56 are each formed in an annular shape, and the tip portions 55 a and 56 a are exposed from the outer periphery 51 c of the surface layer 51.
Accordingly, the tip portions 55 a and 56 a are in contact with the holder opening 19.

The surface layer 51 is configured such that one end 51a of the surface layer 51 is in contact with one overhang 55 and the other end 51b of the surface layer 51 is in contact with the other overhang 56. Is the same as the surface layer 31 of the first embodiment.
That is, both end portions 51a and 51b in the axial direction of the surface layer 51 are covered with a pair of overhang portions 55 and 56 (base material 54).

Thus, by covering the both axial ends 51a and 51b of the surface layer 51 with the base material 54, the base material 54 suppresses the surface layer 51 from being displaced or flowing in the axial direction (arrow A direction). it can.
Thereby, since abrasion of the surface (namely, outer periphery) 51c which contacts the holder opening part 19 among the surface layers 51 can be suppressed, durability of the front bush 50 can be improved.

Moreover, the surface layer 51 can be kept in the state stabilized in the predetermined | prescribed shape by suppressing the displacement and flow to the axial direction (arrow A direction) of the surface layer 51 with a base material.
Therefore, the characteristics (self-adhesiveness, adhesiveness) of the surface layer 51 can be suitably exhibited. Thereby, the sealing performance between the holder opening 19 and the surface layer 51 can be improved.

The front bush (bush) 60 according to the fourth embodiment will be described.
As shown in FIG. 8, the front bush 60 has a protrusion 65 protruding from the base material 64 toward the surface layer 61, and the other configuration is the same as that of the front bush 20 of the first embodiment.

The base material 64 includes an annular protrusion 65 at the outer peripheral center (a part of the base material 64) 64b of the outer periphery 64a, and other configurations are the same as those of the base material 27 of the first embodiment.
The outer periphery center 64b is a part located in the center of the outer periphery 64a with respect to the axial direction (arrow A direction).
The protrusion 65 protrudes in an annular shape from the outer peripheral center 64b toward the surface layer 61 (holder opening 19). Therefore, the annular tip 65 a is exposed from the outer periphery 61 a of the surface layer 61, and is in contact with the holder opening 19.

Thereby, the surface layer 61 has the first surface layer 62 on one side with respect to the axial direction (arrow A direction) and the second surface on the other side with respect to the axial direction (arrow A direction) with the protrusion 65 as a boundary. The surface layer 63 is divided into two parts.
Each of the first surface layer 62 and the second surface layer 63 is a surface layer formed in an annular shape.

Thus, by dividing the surface layer 61 by the protrusions 65, the stress (load) input to the surface layer 61 from the front holder 17 and the support collar 25 is distributed to the first surface layer 62 and the second surface layer 63. Thus, the deformation of the surface layer 61 can be suppressed.
Further, by dividing the surface layer 61 with the protruding portion 65 as a boundary, the protruding portion 65 can suppress displacement and flow of the surface layer 61 in the axial direction (arrow A direction).
Thereby, the surface layer 61 can be kept in a predetermined position or a predetermined shape.

The front bush (bush) 70 according to the fifth embodiment will be described.
As shown in FIG. 9, the front bush 70 includes an annular inner surface layer 72 between the base material 27 and the support collar 25, and other configurations are the same as those of the front bush 20 of the first embodiment.

The inner surface layer 72 is an annular layer integrally formed with an elastic material having the same self-adhesiveness as the surface layer 31 on the inner periphery 28 a of the substrate opening 28 provided in the substrate 27.
The inner surface layer 72 is formed in a thin shape so that the thickness dimension T3 is smaller than the thickness dimension T2 of the base material 27.

Thus, by providing the inner surface layer 72 having self-adhesiveness between the base material 27 and the support collar 25, the support collar 25 (outer periphery 25 a) can be easily placed on the base material opening 28 via the inner surface layer 72. It can be fixed, and further cost reduction can be achieved.
In addition, by providing the inner surface layer 72 having self-adhesiveness between the base material 27 and the support collar 25, the inner surface layer 72 can be firmly adhered to the support collar 25.
As a result, the inner surface layer 72 can prevent the base material 27 from slipping with respect to the support collar 25.

Further, by forming the inner surface layer 72 thinner than the thickness T2 of the base material 27, the spring characteristics of the base material 27 (that is, the front bush 70) can be easily achieved without being affected by the inner surface layer 72. Can be adjusted.
Thus, the performance of the front bush 70 can be sufficiently ensured by preventing the base material 27 from sliding relative to the support collar 25 and making the spring characteristics of the base material 27 (front bush 70) adjustable.

The bush according to the present invention is not limited to the above-described embodiments, and can be changed or improved as appropriate.
For example, in the first to fifth embodiments, the example in which the bush is provided on the suspension arm 16 has been described. However, the present invention is not limited to this, and the suspension arm 16 may be provided on another member such as a link member for suspension.

  Moreover, in the said Example 1 and Examples 3-5, although the example which press-fits a bush to a holder was demonstrated, it is not restricted to this, A bush (surface layer) is vulcanized and formed into a holder like Example 2. It is also possible to integrate them.

  Further, in the fourth embodiment, the example in which the surface layer 61 is divided into the first surface layer 62 and the second surface layer 63 has been described. However, the present invention is not limited to this, and the surface layer 61 is divided into other numbers such as three. Is also possible.

Moreover, in Examples 1-5, although butyl rubber was illustrated as an elastic material which has self-adhesiveness, it is not limited to this.
For example, as other examples, natural rubber (NR), polyisoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber whose energy loss is increased by reducing the degree of vulcanization compared to the base material by blending. It is also possible to use one or more other rubbers selected from (SBR), chloroprene rubber (CR), nitrile rubber (NBR) and the like.

Further, the shape and configuration of the bush, holder, holder opening, support collar, base material, base material opening, surface layer, thick part, groove, inlet, inner surface layer, etc. shown in Examples 1 to 5 Is not limited to those illustrated, and can be changed as appropriate.
In particular, since a special heat treatment process is not required, it is preferable to apply to a holder using a resin material such as a fiber reinforced resin because a further weight reduction can be achieved.

  INDUSTRIAL APPLICABILITY The present invention is suitable for application to an automobile including a bush that elastically couples a holder and a support object as a mechanical component such as a suspension by being accommodated in an opening of a holder formed separately.

  20, 40, 50, 60, 70 ... front bush (bush), 17 ... front holder (holder), 18 ... rear holder (holder), 19 ... holder opening (opening), 25 ... support collar (support) 25a ... outer periphery of support collar (outer periphery of support portion), 27, 54, 64 ... base material, 27a, 54a, 64a ... outer periphery of base material, 28 ... base material opening, 28a ... inner periphery of base material opening , 31, 41, 51, 61 ... surface layer, 42 ... thick part, 45 ... holder, 46 ... groove, 51a, 51b ... both axial ends (axial end) of the surface layer, 64b ... outer periphery of the substrate Center (part of base material), 72 ... inner surface layer.

Claims (5)

A bush in which a support portion is supported by the holder by being housed in an opening of the holder,
A base material that can be bonded to the outer periphery of the support part;
A surface layer integrally formed in a thinner shape than the thickness of the base material with an elastic material having self-adhesiveness on the outer periphery on the opening side of the base material,
A bush characterized by comprising.   2. The bush according to claim 1, wherein a recessed portion is formed on an inner diameter side from the opening of the base material, and the surface layer of a portion corresponding to the recessed portion is formed thick.   2. The bush according to claim 1, wherein an annular groove is formed in the opening of the holder, and the surface layer of a portion corresponding to the groove is formed thick toward the outer periphery.   The bush according to claim 1 or 2, wherein an axial end portion of the surface layer is covered with the base material.   The bush according to any one of claims 1 to 3, wherein a protrusion is protruded from a part of the base material toward the surface layer.

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