JP7178914B2 - Anti-vibration bushing and method for manufacturing anti-vibration bushing - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vibration-isolating bushing provided at a connecting portion of two members and having a vibration-isolating function, and a method for manufacturing the vibration-isolating bushing.

2. Description of the Related Art In an automobile or the like, a vibration isolating bush is provided at a portion connecting two members. This anti-vibration bush plays a role of reducing the transmission of vibration while supporting one of the two members by the other member. A general anti-vibration bush will be described with reference to FIG. FIG. 7 is a schematic cross-sectional view of a conventional anti-vibration bushing, and is a cross-sectional view of the anti-vibration bushing cut along a plane including the central axis of the anti-vibration bushing.

The anti-vibration bushing 700 includes a cylindrical inner cylinder 710, a cylindrical outer cylinder 720 provided concentrically with the inner cylinder 710, and vulcanization bonding to the outer peripheral surface of the inner cylinder 710 and the inner peripheral surface of the outer cylinder 720, respectively. A rubber-like elastic body 730 connecting the inner cylinder 710 and the outer cylinder 720 is provided. The anti-vibration bushing 700 configured as described above has a support function and an anti-vibration function as described above. Here, in order to enhance the support function, it is suitable for the rubber-like elastic body 730 to have high rigidity (high spring constant). (Low spring constant) is more suitable. Thus, the rubber-like elastic body 730 is required to have contradictory properties.

The anti-vibration bushing 700 shown in FIG. 7 has a high spring constant against compressive force and a low spring constant against shear force. That is, when a force acts on the anti-vibration bushing 700 in the radial direction (the direction of the arrow P01 in the drawing) and when a force acts in a direction (prying direction) inclined with respect to the central axis of the anti-vibration bushing 700. , a compressive force acts on the rubber-like elastic body 730 . In this case, the spring constant of the rubber-like elastic body 730 exhibits a property of increasing. On the other hand, when a force acts on the anti-vibration bushing 700 in the axial direction (the direction of the arrow P02 in the figure) and in the direction of rotation (torsion direction) with respect to the central axis of the anti-vibration bushing 700 When a force acts, a shear force acts on the rubber-like elastic body 730 . In this case, the spring constant of the rubber-like elastic body 730 exhibits a low property. In addition, the solid-line arrow in FIG. 7 shows how the compressive force acts, and the dotted-line arrow shows how the shear force acts.

As described above, depending on the direction of the force acting on the anti-vibration bushing 700, the rubber-like elastic body 730 exhibits a property of having a high spring constant or a property of having a low spring constant. Therefore, the anti-vibration bushing 700 is provided at the connecting portion of the two members so that both the supporting function and the anti-vibration function are exhibited.

However, depending on the position of the anti-vibration bushing, the spring constant of the rubber-like elastic body decreases when force acts in the radial direction, and the spring constant of the rubber-like elastic body decreases when force acts in the axial direction. A higher spring constant may also be required. The anti-vibration bushing 700 shown in FIG. 7 cannot meet such requirements. As a technique to increase the spring constant of the rubber-like elastic body when a force acts on the anti-vibration bushing in the axial direction, this technique provides a flange on the inner and outer cylinders to apply a compressive force to the rubber-like elastic body. is also known (see Patent Document 1). However, in this case, even if a force acts on the anti-vibration bushing in the radial direction, the spring constant of the rubber-like elastic body increases, and the above requirement cannot be met.

WO 02/75177 JP 2009-180330 A Japanese Utility Model Laid-Open No. 2-11244 JP 2009-216135 A JP-A-2002-295560 JP-A-10-274268

An object of the present invention is to reduce the spring constant of the rubber-like elastic body when force acts on the anti-vibration bushing in the radial direction, and to reduce the spring constant of the rubber-like elastic body when force acts in the axial direction. To provide an anti-vibration bush capable of increasing the height of the anti-vibration bush and a method for manufacturing the anti-vibration bush.

The present invention employs the following means to solve the above problems.

The anti-vibration bushing of the present invention is
an inner cylinder unit;
an outer cylinder provided concentrically with the inner cylinder unit;
a rubber-like elastic body that is vulcanized and adhered to the outer peripheral surface of the inner cylinder unit and the inner peripheral surface of the outer cylinder, and that connects the inner cylinder unit and the outer cylinder;
An anti-vibration bushing comprising
The inner cylinder unit is composed of a first tubular member and a second tubular member arranged coaxially,
The outer peripheral surface of the first tubular member is arranged on the side opposite to the second tubular member via the arrangement position of the first small diameter surface and the first small diameter surface, and has a larger outer diameter than the first small diameter surface. 1 large diameter surface and a first inclined surface connecting the first small diameter surface and the first large diameter surface,
The outer peripheral surface of the second tubular member is arranged on the side opposite to the first tubular member via the arrangement position of the second small diameter surface and the second small diameter surface, and has a larger outer diameter than the second small diameter surface. Having two large diameter surfaces and a second inclined surface connecting the second small diameter surface and the second large diameter surface,
The inner peripheral surface of the outer cylinder is arranged at a position facing the first small diameter surface and the second small diameter surface, and has an inner diameter larger than the outer diameters of the first small diameter surface and the second small diameter surface. A center-facing surface smaller than the outer diameter of the large-diameter surface and the second large-diameter surface; It is characterized by having both side opposing surfaces that increase in diameter as it separates from the surface.

According to the present invention, when a radial force acts on the anti-vibration bushing, the portion of the rubber-like elastic body that is sandwiched between the first inclined surface and both opposing surfaces and the portion that is sandwiched between the second inclined surface and both opposing surfaces. In the bent part, part of the force is also distributed in the axial direction. Thereby, the spring constant of the rubber-like elastic body can be reduced. Further, when an axial force acts on the anti-vibration bushing, the rubber-like elastic body at the portion sandwiched between the first inclined surface and the opposed surfaces on both sides and the portion sandwiched between the second inclined surface and the opposed surfaces on both sides Since part of the compressive force acts in the axial direction, the spring constant of the rubber-like elastic body can be increased.

Further, in the present invention, a gap is provided between the first tubular member and the second tubular member .

As a result, when the anti-vibration bushing is used, the rubber-like elastic body is compressed by incorporating the first tubular member and the second tubular member close to each other so as to eliminate the above-mentioned gap and assembling them at a desired position. be able to. Therefore, the drawing process can be omitted.

Further, the method for manufacturing the anti-vibration bushing of the present invention comprises:
In the method for manufacturing the anti-vibration bushing described above,
disposing the outer cylinder, the first tubular member, the second tubular member, and an annular member closing the gap between the first tubular member and the second tubular member in a mold;
Cavities formed between the inner peripheral surface of the outer cylinder and the outer peripheral surfaces of the first tubular member, the second tubular member and the annular member are filled with the rubber-like elastic material and vulcanized. a molding step;
removing the annular member after vulcanization;
characterized by having

As described above, according to the present invention, the spring constant of the rubber-like elastic body is reduced when a force acts on the anti-vibration bushing in the radial direction, and the rubber-like elastic body when a force acts on the vibration-isolating bush in the axial direction. The spring constant of the elastic body can be increased.

FIG. 1 is a schematic cross-sectional view of an anti-vibration bushing according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a usage example of the anti-vibration bushing according to the embodiment of the present invention. FIG. 3 is a diagram for explaining the mechanism of the anti-vibration bushing according to the embodiment of the present invention. FIG. 4 is a mechanism explanatory diagram of the anti-vibration bushing according to the embodiment of the present invention. FIG. 5 is a manufacturing process diagram of the anti-vibration bushing according to the embodiment of the present invention. FIG. 6 is a side view of parts used in manufacturing the anti-vibration bushing according to the embodiment of the present invention. FIG. 7 is a schematic cross-sectional view of a conventional anti-vibration bushing.

BEST MODE FOR CARRYING OUT THE INVENTION A mode for carrying out the present invention will be exemplarily described in detail below based on an embodiment with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only to them, unless otherwise specified. .

(Example)
An anti-vibration bushing according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6. FIG. FIG. 1 is a schematic cross-sectional view of an anti-vibration bushing according to an embodiment of the present invention. The anti-vibration bushing 10 according to this embodiment has a rotationally symmetrical shape, and FIG. 1 is a cross-sectional view of the anti-vibration bushing taken along a plane including the central axis of the anti-vibration bushing. FIG. 2 is a schematic cross-sectional view showing a usage example of the anti-vibration bushing according to the embodiment of the present invention. 3 and 4 are diagrams for explaining the mechanism of the anti-vibration bushing according to the embodiment of the present invention. 3 and 4 show a part of the cross-sectional view of the anti-vibration bushing, but hatching is omitted for the sake of convenience. FIG. 5 is a manufacturing process diagram of the anti-vibration bushing according to the embodiment of the present invention, showing each member in cross section. FIG. 6 is a side view of parts used in manufacturing the anti-vibration bushing according to the embodiment of the present invention. In the following description, the direction in which the center axis of the anti-vibration bushing extends is called the "axial direction", and the direction perpendicular to the center axis is called the "radial direction".

<Anti-vibration bushing>
In particular, referring to FIG. 1, the configuration of the anti-vibration bushing 10 according to this embodiment will be described. The anti-vibration bushing 10 comprises an inner cylinder unit 100, an outer cylinder 200 provided concentrically with the inner cylinder unit 100, and a rubber-like elastic body 300 connecting the inner cylinder unit 100 and the outer cylinder 200. .

The inner cylinder unit 100 is composed of a first tubular member 110 and a second tubular member 120 which are coaxially arranged with a gap S therebetween. Both the first tubular member 110 and the second tubular member 120 are made of metal.

The outer peripheral surface of the first tubular member 110 is arranged on the side opposite to the second tubular member 120 via the arrangement position of the first small diameter surface 111 and the first small diameter surface 111 . and a first inclined surface 113 connecting the first small-diameter surface 111 and the first large-diameter surface 112 . The first inclined surface 113 according to this embodiment is configured by a tapered surface. However, the first inclined surface in the present invention can also be configured with a curved surface that is curved when viewed in cross section. Both the first small-diameter surface 111 and the first large-diameter surface 112 are formed of cylindrical surfaces. In addition, the inner peripheral surface of the first tubular member 110 is configured by a cylindrical surface except for the chamfered portions at the ends.

In addition, the outer peripheral surface of the second cylindrical member 120 is arranged on the side opposite to the first cylindrical member 110 via the arrangement position of the second small diameter surface 121 and the second small diameter surface 121 . and a second inclined surface 123 connecting the second small-diameter surface 121 and the second large-diameter surface 122 . The second inclined surface 123 according to this embodiment is configured by a tapered surface. However, the second inclined surface in the present invention can also be configured with a curved surface that is curved when viewed in cross section. Both the second small-diameter surface 121 and the second large-diameter surface 122 are formed of cylindrical surfaces. In addition, the inner peripheral surface of the second tubular member 120 is configured by a cylindrical surface except for the chamfered portions at the ends.

In this embodiment, the first tubular member 110 and the second tubular member 120 are configured by the same parts. That is, the first tubular member 110 and the second tubular member 120 have the same size, shape, and material. By arranging the first tubular member 110 and the second tubular member 120 so that their central axes coincide with each other and with a gap S therebetween, the end surfaces of the small-diameter portions face each other, An inner cylinder unit 100 is constructed.

Outer cylinder 200 is configured by a metallic annular member. The inner peripheral surface of the outer cylinder 200 includes a central facing surface 210 arranged at a position facing the first small diameter surface 111 of the first tubular member 110 and the second small diameter surface 121 of the second tubular member 120, It is composed of opposing surfaces 220 and 230 provided on both sides of the central opposing surface 210 . The inner diameter of the central facing surface 210 is larger than the outer diameters of the first small diameter surface 111 and the second small diameter surface 121 and smaller than the outer diameters of the first large diameter surface 112 and the second large diameter surface 122 . Also, the opposing surfaces 220 and 230 are arranged at positions facing the first inclined surface 113 of the first tubular member 110 and the second inclined surface 123 of the second tubular member 120, respectively. Moreover, these both side facing surfaces 220 and 230 are configured by inclined surfaces that increase in diameter as they separate from the central facing surface 210 . Both of the opposing surfaces 220 and 230 according to this embodiment are tapered surfaces. However, the opposing surfaces on both sides in the present invention can also be configured with curved surfaces that form curves when viewed in cross section. Moreover, the outer peripheral surface of the outer cylinder 200 is configured by a cylindrical surface except for a portion of both ends.

The rubber-like elastic body 300 is obtained by vulcanization molding, and is formed between the outer peripheral surface of the inner cylinder unit 100 (the outer peripheral surface of the first cylindrical member 110 and the outer peripheral surface of the second cylindrical member 120) and the outer cylinder 200. They are vulcanized and bonded to the inner peripheral surface. In this embodiment, the rubber-like elastic body 300 is vulcanized and bonded to the entire outer peripheral surface of the inner cylinder unit 100 and the entire inner peripheral surface of the outer cylinder 200 . In the rubber-like elastic body 300, the inner peripheral surface of the outer cylinder 200, the first small diameter surface 111 and the first inclined surface 113 of the first tubular member 110, and the second small diameter surface 121 of the second tubular member 120 are formed. and the second inclined surface 123 exerts a vibration isolation function.

<Usage example of anti-vibration bushing>
A usage example of the anti-vibration bushing 10 according to the present embodiment will be described with reference to FIG. The anti-vibration bushing 10 is provided at a portion connecting the two members. Here, for convenience, one of the two members will be referred to as the first member 610 and the other member will be referred to as the second member 620 . A fitting hole 611 is provided in the first member 610 . The anti-vibration bushing 10 is fixed to the fitting hole 611 by press fitting. That is, the outer peripheral surface of the outer cylinder 200 of the anti-vibration bushing 10 is fixed in close contact with the inner peripheral surface of the fitting hole 611 . In this way, the first member 610 and the second member 620 are fixed by the bolt 630 and the nut 640 while the anti-vibration bushing 10 is press-fitted into the fitting hole 611 . At this time, the shaft portion 631 of the bolt 630 is inserted into the inner cylinder unit 100 of the anti-vibration bushing 10, and both ends of the inner cylinder unit 100 are tightened by the bolt 630 and the nut 640. becomes. In addition, by tightening with the bolt 630 and the nut 640, the first tubular member 110 and the second tubular member 120 are brought closer to each other, so that there is no gap (in contact or nearly in contact) (indicated by arrow S0 in FIG. 2). see the part indicated). Thereby, the rubber-like elastic body 300 is in a compressed state.

With the above configuration, one of the first member 610 and the second member 620 is supported by the other. In addition, the transmission of vibration is reduced by the anti-vibration bushing 10 .

<Excellent points of the anti-vibration bushing according to the present embodiment>
According to the anti-vibration bushing 10 of this embodiment, the spring constant of the rubber-like elastic body 300 is reduced when force acts on the anti-vibration bushing 10 in the radial direction, and the force acts in the axial direction. In this case, the spring constant of the rubber-like elastic body 300 can be increased. This point will be described in more detail with reference to FIGS. 3 and 4. FIG.

FIG. 3 shows how force acts on the anti-vibration bushing 10 when radial force (force in the direction of arrow P11 in the figure) acts. In the figure, solid arrows indicate forces in the compression direction, and dotted arrows indicate forces in the shear direction. When a radial force P11 acts on the anti-vibration bushing 10, the portion of the rubber-like elastic body 300 sandwiched between the first inclined surface 113 and both-sided opposing surfaces 220, and the second inclined surface 123 and both-sided opposing surfaces 230 are affected. In the pinched part, part of the force is also distributed in the axial direction. As a result, the spring constant of the rubber-like elastic body 300 can be reduced when force acts on the anti-vibration bushing 10 in the radial direction.

FIG. 4 shows how an axial force acts on the anti-vibration bushing 10 (force in the direction of arrow P12 in the drawing). In the figure, solid arrows indicate forces in the compression direction, and dotted arrows indicate forces in the shear direction. When an axial force P12 acts on the anti-vibration bushing 10, a portion of the rubber-like elastic body 300 sandwiched between the first inclined surface 113 and the opposite surfaces 220 on both sides, and the second inclined surface 123 and the opposite surfaces 230 on both sides, Part of the compressive force acts axially in the pinched portion. As a result, the spring constant of the rubber-like elastic body 300 can be increased when force acts on the anti-vibration bushing 10 in the axial direction.

Further, in the anti-vibration bushing 10 according to this embodiment, the rubber-like elastic body 300 is vulcanized and bonded to both the inner cylinder unit 100 and the outer cylinder 200 . Therefore, even when a twisting force acts on the rubber-like elastic body 300 due to the force acting in the direction in which the inner cylinder unit 100 and the outer cylinder 200 rotate relative to each other, the rubber-like elastic body 300 and the inner cylinder will not rotate. There is no possibility of sliding between the unit 100 and the outer cylinder 200 . Therefore, the rigidity in the torsional direction can be increased, and the relative rotation of the inner cylinder unit 100 and the outer cylinder 200 can be suppressed.

Further, in the anti-vibration bushing 10 according to this embodiment, a gap S is provided between the first cylindrical member 110 and the second cylindrical member 120 that constitute the inner cylinder unit 100 . This makes it possible to omit the drawing process. This point will be described in more detail. In the case of a type of anti-vibration bushing in which an outer cylinder and an inner cylinder are used as insert parts and a rubber-like elastic material is insert-molded between them, the rubber-like elastic body may is in a state in which a tensile stress is applied. This is because the rubber material expands because it is in a high temperature state at the time of molding, and although the rubber-like elastic body tries to be compressed by cooling after molding, the gap between the highly rigid outer cylinder and the inner cylinder remains. This is because there is almost no change. Therefore, if the anti-vibration bushing is used as it is (a state in which a tensile stress is applied to the rubber-like elastic body), the durability will deteriorate. Therefore, in such anti-vibration bushings, measures such as pre-compression to reduce the outer diameter or inner diameter (drawing process) are usually taken to remove the tensile stress (for example, JP-A-2-176226 (see publication). On the other hand, in the anti-vibration bushing 10 according to the present embodiment, as described above, there is a gap between the first tubular member 110 and the second tubular member 120 when assembled at a desired position. By removing the elastic member 300, the rubber-like elastic body 300 can be in a compressed state. Therefore, no tensile stress acts on the rubber-like elastic body 300, or the tensile stress acting on the rubber-like elastic body 300 can be reduced. As described above, the drawing process can be omitted. Moreover, the durability of the rubber-like elastic body 300 is not lowered.

<Manufacturing method of anti-vibration bushing>
Particularly, with reference to FIGS. 5 and 6, a method of manufacturing the anti-vibration bushing 10 according to this embodiment will be described. The anti-vibration bushing 10 according to this embodiment can be obtained by insert molding using the inner cylinder unit 100 and the outer cylinder 200 as insert parts. Since the mold used for insert molding is a known technology, the description thereof will be omitted.

First, the outer cylinder 200, the first tubular member 110 and the second tubular member 120 that constitute the inner cylinder unit 100, and the annular A member 500 is placed in a mold (not shown). The first cylindrical member 110 and the second cylindrical member 120 are arranged so as to be inserted into the outer cylinder 200 from both sides of the outer cylinder 200 (see FIG. 5A). Moreover, the annular member 500 is configured by an annular member made of resin. The annular member 500 is provided with an abutment portion 510 at one location in the circumferential direction. A handle 520 that protrudes radially inward is provided in the vicinity of the abutment portion 510 of the annular member 500 .

FIG. 5(b) shows a state in which various members are arranged in the mold. A cavity C (portion surrounded by a thick dotted line) is formed between the inner peripheral surface of the outer cylinder 200 and the outer peripheral surfaces of the first tubular member 110 , the second tubular member 120 and the annular member 500 . The cavity C is filled with the material (rubber material) of the rubber-like elastic body 300 and vulcanized.

After vulcanization molding, the insert-molded product is removed from the mold. Annular member 500 is then removed. By pulling the handle 520, the annular member 500 can be easily removed. The anti-vibration bushing 10 according to the present embodiment can be obtained through the steps described above.

In the manufacturing method described above, by using the annular member 500 , when filling the material of the rubber-like elastic body 300 , the material flows through the gap between the first tubular member 110 and the second tubular member 120 . shows how to prevent leakage. However, without using the annular member 500, it is also possible to adopt a manufacturing method of removing the material leaked from the gap after molding the insert-molded product.

10 anti-vibration bushing 100 inner cylinder unit 110 first cylindrical member 111 first small diameter surface 112 first large diameter surface 113 first inclined surface 120 second cylindrical member 121 second small diameter surface 122 second large diameter surface 123 second second Inclined surface 200 Outer cylinder 210 Central opposing surface 220, 230 Both side opposing surfaces 300 Rubber-like elastic body 500 Annular member 510 Abutment 520 Handle 610 First member 611 Fitting hole 620 Second member 630 Bolt 631 Shaft 640 Nut S Gap

Claims (2)

an inner cylinder unit;
an outer cylinder provided concentrically with the inner cylinder unit;
a rubber-like elastic body that is vulcanized and adhered to the outer peripheral surface of the inner cylinder unit and the inner peripheral surface of the outer cylinder, and that connects the inner cylinder unit and the outer cylinder;
An anti-vibration bushing comprising
The inner cylinder unit is composed of a first tubular member and a second tubular member arranged coaxially,
The outer peripheral surface of the first tubular member is arranged on the side opposite to the second tubular member via the arrangement position of the first small diameter surface and the first small diameter surface, and has a larger outer diameter than the first small diameter surface. 1 large diameter surface and a first inclined surface connecting the first small diameter surface and the first large diameter surface,
The outer peripheral surface of the second tubular member is arranged on the side opposite to the first tubular member via the arrangement position of the second small diameter surface and the second small diameter surface, and has a larger outer diameter than the second small diameter surface. Having two large diameter surfaces and a second inclined surface connecting the second small diameter surface and the second large diameter surface,
The inner peripheral surface of the outer cylinder is arranged at a position facing the first small diameter surface and the second small diameter surface, and has an inner diameter larger than the outer diameters of the first small diameter surface and the second small diameter surface. A center-facing surface smaller than the outer diameter of the large-diameter surface and the second large-diameter surface; and a surface facing both sides that expands in diameter as it moves away from the surface ,
A vibration isolating bush, wherein a gap is provided between the first tubular member and the second tubular member . A method for manufacturing the anti-vibration bushing according to claim 1 ,
disposing the outer cylinder, the first tubular member, the second tubular member, and an annular member closing the gap between the first tubular member and the second tubular member in a mold;
Cavities formed between the inner peripheral surface of the outer cylinder and the outer peripheral surfaces of the first tubular member, the second tubular member and the annular member are filled with the rubber-like elastic material and vulcanized. a molding step;
removing the annular member after vulcanization;
A method for manufacturing an anti-vibration bush, comprising:

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