JP4107610B2 - Vibration isolator - Google Patents

Description

The present invention includes an inner cylinder, an outer cylinder, an intermediate cylinder fitted into the outer cylinder, a rubber-like elastic body that is vulcanized and formed between the intermediate cylinder and the inner cylinder, and connects the intermediate cylinder and the inner cylinder. relates to at least one side a pair of a liquid chamber, liquid filled in the vibration damping device is provided with an orifice for communicating the pair of liquid chambers with each other to the chamber wall of the rubber-like elastic body.

  As an example of the above-described vibration isolator, there is a liquid-filled vibration isolator provided between a front member of a rear suspension of an automobile and a vehicle body frame or between a rear member of a rear suspension and a vehicle body frame. These vibration isolation devices are press-fitted into the vertical holes on the member side, and are connected and fixed to the vehicle body frame by connecting bolts inserted through the inner cylinder. Then, the rubber-like elastic body is elastically deformed by the input of vibration, the inner cylinder and the outer cylinder are relatively displaced, and the volumes of both liquid chambers change. Thereby, the liquid flows through the orifice, and the vibration damping effect is obtained by the liquid flow effect. Conventionally, the above-described liquid-filled vibration isolator has a straight surface in which the outer peripheral surface of the inner cylinder portion and the inner peripheral surface of the intermediate cylinder portion where the rubber-like elastic body is vulcanized are parallel to the axis of the inner and outer tubes Was formed.

According to the above-described conventional configuration, when the inner cylinder and the outer cylinder are relatively displaced in the axial direction (hereinafter referred to as “vertical direction”), only the shearing force acts on the rubber-like elastic body. The spring constant in the vertical direction of the body was small. For this reason, the rigidity of the automobile in the roll direction has become weak, and there remains room for improvement in terms of handling stability.
As means for increasing the spring constant, there are provided an overhang portion projecting perpendicularly from the inner tube portion toward the intermediate tube portion side, and an overhang portion projecting perpendicularly from the intermediate tube portion toward the inner tube portion side. A structure in which the elastic body is sandwiched from above and below can be considered. However, in this structure, there is a problem that the compressive force applied to the rubber-like elastic body becomes too large and the durability of the rubber-like elastic body is lowered.
The present invention has been made in view of the above circumstances, and its object is to improve vibration control stability of the automobile and improve the durability of the rubber-like elastic body between the inner and outer cylinders. The point is to provide a device.

The feature of the present invention is that
An inner cylinder, an outer cylinder, an intermediate cylinder fitted into the outer cylinder, a rubber-like elastic body that is vulcanized and formed between the intermediate cylinder and the inner cylinder, and connects the intermediate cylinder and the inner cylinder; A liquid-filled vibration isolator provided with a pair of liquid chambers having the rubber-like elastic body as a chamber wall and an orifice for communicating the pair of liquid chambers,
A pair of first inclined wall portions having a first inclined surface located on the intermediate cylinder side toward the one axial end side of the inner and outer cylinders are arranged on the outer peripheral side of the axial intermediate part of the inner cylinder. A pair of second inclined wall portions provided with a second inclined surface provided on the inner cylinder side toward the other axial end side of the inner and outer cylinders are provided so as to be positioned across the shaft core. Provided so as to be located on the inner peripheral side of the middle of the direction with the pair of first inclined wall portions of the inner cylinder interposed therebetween, and the rubber-like elastic body is interposed between the first inclined surface and the second inclined surface Let
A cylindrical metal fitting formed by vulcanizing a first rubber wall between one end of the outer cylinder is externally fitted to one end of the inner cylinder, and one liquid chamber is connected to the first rubber wall and the first rubber. The first rubber wall is formed between a ring-shaped orifice forming member provided between the inner and outer cylinders so as to face the wall, and the other liquid chamber is disposed between the orifice forming member and the orifice forming member. Between the second rubber wall provided on the opposite side of
The orifice forming member is composed of a cylindrical portion that forms the orifice between the inner cylinder and a flange that protrudes radially outward from one end of the cylindrical portion, and an outer peripheral portion of the flange is The intermediate cylinder is clamped and fixed between one end of the intermediate cylinder and a step portion made of a vulcanized rubber member on the inner peripheral surface of the one end of the outer cylinder, and the first rubber wall protrudes toward the one liquid chamber. And the flange shape is set so that the longitudinal cross-sectional shape of the flange is the shape along the vertical cross-sectional shape of the first rubber wall.

(A) According to this configuration, when the inner cylinder and the outer cylinder are relatively displaced in the axial direction, the first inclined surface of the first inclined wall portion on the inner cylinder side and the second inclined wall on the intermediate cylinder side are accordingly accompanied. The rubber-like elastic body between them is pressed with the second inclined surface of the part . Thereby, compressive force and shearing force are applied to the rubber-like elastic body, the spring constant of the rubber-like elastic body in the axial direction of the inner cylinder and the intermediate cylinder can be increased, and the rigidity in the roll direction of the automobile is increased. be able to. In addition, for example, compared to a configuration in which the rubber-like elastic body is pressed with an overhang portion that projects at a right angle from the inner tube portion to the intermediate tube portion side and an overhang portion that projects at a right angle from the intermediate tube portion to the inner tube portion side, said compression force can be reduced, Ru can be eliminated the problem of compressive force applied to the rubber-like elastic body is too large.

(B) The liquid-filled vibration isolator having the above-described configuration in which a pair of liquid chambers are arranged in the axial direction of the inner and outer cylinders is provided, for example, between a rear member of a rear suspension of an automobile and a vehicle body frame. In this suspension structure, a large load is applied to the rubber-like elastic body when it is assembled to an automobile and the weight of the vehicle body is applied. Therefore, according to the conventional structure, the relative displacement between the inner cylinder and the outer cylinder is large, and the durability of the rubber-like elastic body is likely to be lowered. Therefore, in general, a stopper rubber against the stopper fitting that is extended from one end of the inner cylinder is vulcanized on a flange that is formed on one end of the outer cylinder, and this stopper rubber is always applied to the stopper fitting in the axial direction. I support it. However, in this structure, the amount of sag of the stopper rubber during heat aging increases, and the spring constant tends to increase too much.
On the other hand, according to the above configuration of the present invention , when the weight of the vehicle body is added to the automobile, a compression force is generated in the rubber-like elastic body. It can be made smaller than the conventional structure in which only a shearing force is generated in the rubber-like elastic body. As a result, the durability of the rubber-like elastic body can be improved. In addition, the stopper rubber does not always have to be brought into contact with the stopper fitting, and an increase in the amount of the stopper rubber can be suppressed, so that the spring constant can be suppressed from being excessively increased.

The orifice forming member includes a cylindrical portion that forms an orifice with the inner cylinder, and a flange that protrudes radially outward from one end of the cylindrical portion, and the first rubber wall is formed on one side. The flange is set to have a circular arc shape that is convex to the liquid chamber side, and the shape of the flange is set so that the vertical cross-sectional shape of the flange is in line with the vertical cross-sectional shape of the first rubber wall. The liquid can be smoothly guided to both the liquid chambers via the section, and desired vibration isolation characteristics can be easily obtained.
Since the outer peripheral portion of the flange is sandwiched and fixed by one end portion of the intermediate cylinder and a step portion made of a rubber member vulcanized and formed on the inner peripheral surface on the one end portion side of the outer cylinder, the assembly structure of each member The strength of can be increased.

In the present invention, the one liquid chamber is formed around one end of the inner cylinder over the entire circumference, and a part of the other liquid chamber is formed around the inner cylinder over the entire circumference. There is an effect.

(C) One liquid chamber is formed over the entire circumference around one end of the inner cylinder, and a part of the other liquid chamber is formed over the entire circumference around the inner cylinder to sufficiently secure the volume of the liquid chamber. be able to.

In the present invention, a cylindrical resin material integrally provided with the first inclined wall portion is press-fitted and fitted into the inner cylinder, and an end portion of the cylindrical resin material is received and supported at an end portion of the cylindrical metal fitting. Then, if the second inclined wall portion is formed in the intermediate cylinder by denting a part of the straight cylindrical intermediate cylinder inward in the radial direction, the following action can be achieved.

(D) The weight can be reduced by forming the first inclined wall portion with a resin material. Furthermore, since the second inclined wall portion is formed in the intermediate cylinder by denting a part of the straight cylindrical intermediate cylinder inward in the radial direction, the second inclined wall portion is easily formed.

In the present invention , when the other end portion of the intermediate tube is received in the axial direction by a bent portion formed at the other end portion of the outer tube, the following operation can be achieved.

(E) that is capable of stronger intensity of the assembled structure.

According to the present invention , it is possible to provide a liquid-filled vibration isolator capable of improving the steering stability of an automobile and improving the durability of the rubber-like elastic body between the inner and outer cylinders. .

1 , 2 and 3 show a cylindrical liquid-filled vibration isolator provided between a rear member of a rear suspension of an automobile and a vehicle body frame. This liquid-filled vibration isolator includes an inner cylinder 1, an outer cylinder 2, an intermediate cylinder 7 fitted into the outer cylinder 2, and a vulcanization molding between the intermediate cylinder 7 and the inner cylinder 1. A rubber-like elastic body 3 for connecting the inner cylinder 1, a pair of liquid chambers 4A, 4B having at least one side as a chamber wall, and an annular orifice 5 for communicating the pair of liquid chambers 4A, 4B with each other. And.

In addition, a pair of first inclined wall portions 42 having a first inclined surface 41 located on the intermediate tube 7 side toward the axial one end portions 1A and 2A (lower end portions) of the inner and outer tubes 1 and 2 are provided on the inner tube 1. Provided on the outer peripheral side of the axially intermediate portion so as to sandwich the inner core O of the inner cylinder 1 (see FIGS. 4, 6 and 12), the other axial end 1B of the inner and outer cylinders 1 and 2, A pair of second inclined wall portions 44 having a second inclined surface 43 positioned on the inner cylinder 1 side toward the 2B (lower end) side are disposed on the inner peripheral side of the intermediate portion in the axial direction of the intermediate tube 7. The rubber-like elasticity is provided between the first inclined surface 41 and the second inclined surface 43 so as to be positioned between the pair of first inclined wall portions 42 (see FIGS. 4, 6, 10, and 11). The body 3 is interposed. This liquid-filled vibration isolator is press-fitted in a vertical posture into a vertical collar 6 provided on a rear member, and is connected and fixed to a vehicle body frame 30 with a connecting bolt (not shown) inserted through the inner cylinder 1.

The configuration of each part will be described. As shown in FIGS. 2, 7, 8, and 9, a cap-shaped tube fitting 51 in which a first rubber wall 50 is vulcanized between the one end 2 </ b> A of the outer tube 2. Is fitted and fitted to one end 1A of the inner cylinder 1 so that one liquid chamber 4A (hereinafter referred to as “lower liquid chamber 4A”) faces the first rubber wall 50 and the first rubber wall 50. It is formed between a circular ring-shaped orifice forming member 52 provided between the inner and outer cylinders 1 and 2, and the other liquid chamber 4B (hereinafter referred to as “upper liquid chamber 4B”) is formed as an orifice forming member 52 and the orifice. It is formed between a second rubber wall 53 (see FIG. 1) provided on the opposite side of the first rubber wall 50 with the forming member 52 interposed therebetween. More specifically, the lower liquid chamber 4A is formed around the one end 1A of the inner cylinder 1 over the entire circumference, the upper liquid chamber 4B is formed around the inner cylinder 1 over the entire circumference, and the upper liquid chamber 4B is formed. It is formed between the pair of first inclined wall portions 42 and the rubber-like elastic body 3 in the circumferential direction of the inner and outer cylinders 1 and 2.

A cylindrical resin material 54 integrally provided with the first inclined wall portion 42 is press-fitted and fitted into the inner cylinder 1, and the end portion 54 A of the cylindrical resin material 54 is received and supported by the end portion 51 A of the cylindrical metal fitting 51. As shown in FIGS. 10 and 11, a part of the straight cylindrical intermediate cylinder 7 is recessed inwardly in the intermediate cylinder 7 by denting a part of the vertical cylindrical shape in the shape of “<” in the radial direction. A wall 44 is formed. Liquid is also sealed between the back surface of the second inclined wall portion 44 and the outer cylinder 2 (see FIG. 2).

The orifice forming member 52 includes a cylindrical portion 55 that forms the orifice 5 with the inner cylinder 1, and a flange 56 that projects radially outward from one end of the cylindrical portion 55. The outer peripheral portion is sandwiched and fixed by one end portion 57 of the intermediate cylinder 7 and a step portion 58 made of a rubber member vulcanized and formed on the inner peripheral surface of the outer cylinder 2 on the one end portion 2A side, and the first rubber wall 50 is lowered. and sets to the side fluid chamber 4A side convex arcuate cross-section, so that longitudinal section of the flange 56 is shaped along the longitudinal section of the first rubber wall 50 is to set the shape of the flange 56 . The other end 59 of the intermediate cylinder 7 is received in the axial direction by a bent part 60 formed at the other end 2B of the outer cylinder 2.

As shown in FIGS. 2, 7, 8, and 9, a stopper rubber 62 for the stopper fitting 31 that projects from the one end 1 </ b> A side of the inner cylinder 1 is attached to a flange 61 that projects from the one end 2 </ b> A of the outer cylinder 2. The vulcanization molding is performed so as to be spaced apart from the stopper fitting 31 in the axial direction. The stopper fitting 31 is formed in a ring disk shape, and is clamped and fixed between the head of the connecting bolt and one end of the inner cylinder 1 (specifically, a washer 32).

As shown in FIGS. 2, 4, 5, and 6, the pair of stopper portions 13 that are located across the axis O of the inner cylinder 1 from a direction different from the pair of first inclined wall portions 42 are provided. A rubber inner peripheral wall 63 that forms a chamber wall of the upper liquid chamber 4B is vulcanized at the inner peripheral portion of the intermediate cylinder 7 and bulged at the end 54B of the resin material 54 on the other end 1B side of the inner cylinder 1. The rubber inner peripheral wall 63 is formed with a pair of straight holes 64 positioned on the radially outer side of the pair of stopper portions 13. The other direction is a direction orthogonal to the direction in which the pair of first inclined wall portions 42 sandwich the axis O. The pair of straight holes 64 have an arc shape in plan view, and are formed in deep holes whose bottoms reach the vicinity of the upper end of the cylindrical part 55 of the orifice forming member 52. The rubber-like elastic body 3, the second rubber wall 53, and the rubber inner peripheral wall 63 are integrally formed by vulcanization molding. The other end 1B side of the inner cylinder 1 is slightly extended outward in the radial direction. A ring disc-like stopper rubber 66 is fitted on the base portion of the overhang portion 65.

The first inclined surface 41 and the second inclined surface 43 are parallel to each other. The inclination angles θ1 and θ2 (see FIGS. 5 and 11) of the inner and outer cylinders 1 and 2 with respect to the axis O are set to 25 °. The first inclined surface 41 and the second inclined surface 43 do not overlap in the axial direction of the inner and outer cylinders 1 and 2.
When vibration is input to the liquid-filled vibration isolator having the above structure, the inner cylinder 1 and the outer cylinder 2 are relatively displaced, and the rubber-like elastic body 3, the first rubber wall 50, the second rubber wall 53, and the like are elastically deformed. As a result, the volumes of the two liquid chambers 4A and 4B change, and the liquid flows through the orifice 5. A vibration damping effect can be obtained by this liquid flow effect.

[Another embodiment]
(1) A structure in which the inclination of the first inclined surface 41 and the second inclined surface 43 is opposite to that of the above embodiment may be employed. For example, a pair of first inclined wall portions 42 having a first inclined surface 41 positioned on the intermediate tube 7 side toward the axial upper end portions 1B and 2B (corresponding to one end portion) of the inner and outer tubes 1 and 2 1 is provided so as to be positioned on the outer peripheral side of the intermediate portion in the axial direction with the axis O of the inner cylinder 1 sandwiched therebetween, and the axial lower end portions 1A, 2A (corresponding to the other end portion) of the inner and outer tubes 1, 2 A pair of second inclined wall portions 44 having a second inclined surface 43 located on the inner cylinder 1 side is provided on the inner peripheral side of the axial intermediate portion of the intermediate cylinder 7, and the pair of first inclined wall portions of the inner cylinder 1. The rubber-like elastic body 3 may be interposed between the first inclined surface 41 and the second inclined surface 43.
(2) In the above embodiment, the first inclined surface 41 and the second inclined surface 43 may not be parallel to each other. Moreover, the numerical value quoted by the above embodiment is an example, and another numerical value may be sufficient as it.

Plan view of liquid-filled vibration isolator 1 shows a liquid-filled vibration isolator attached to a vehicle body frame, and a cross-sectional view taken along the line D-O-D in FIG. Bottom view of liquid-filled vibration isolator Plan view of inner cylinder, intermediate cylinder, etc. before mounting the outer cylinder Longitudinal sectional view of the inner cylinder and intermediate cylinder before mounting the outer cylinder Bottom view of inner cylinder, intermediate cylinder, etc. before mounting the outer cylinder Plan view of outer cylinder Longitudinal section of outer cylinder Bottom view of outer cylinder Plan view of the intermediate cylinder A-A-A cross-sectional view of FIG. Top view of the inner cylinder

Explanation of symbols

1 inner cylinder
1A Axial end
1B Axial other end
2 outer cylinder
2A Axial end
2B other axial end
3 Rubber-like elastic body
4A, 4B liquid chamber
5 Orifice
7 Intermediate tube
41 1st inclined surface
42 1st inclination wall part
43 Second inclined surface
44 Second inclined wall
50 1st rubber wall
51 Tube fitting
51A End of tube fitting
52 Orifice forming member
53 Second rubber wall
54 Resin material
54A End of resin material
55 Tube
56 Flange
57 One end of the intermediate tube
58 steps
59 The other end of the intermediate tube
60 Folding part
O Inner cylinder axis

Claims (4)

The inner cylinder (1), the outer cylinder (2), the intermediate cylinder (7) fitted into the outer cylinder (2), and the intermediate cylinder (7) and the inner cylinder (1) are vulcanized. A rubber-like elastic body (3) connecting the intermediate cylinder (7) and the inner cylinder (1), and at least one side of the pair of liquid chambers (4A), (4B) having the rubber-like elastic body (3) as a chamber wall. ) And an orifice (5) for communicating the pair of liquid chambers (4A) and (4B) with each other,
A pair of first inclined walls provided with a first inclined surface (41) positioned closer to the intermediate cylinder (7) toward one end (1A), (2A) in the axial direction of the inner and outer cylinders (1), (2). A portion (42) is provided on the outer peripheral side of the axially intermediate portion of the inner cylinder (1) so as to sandwich the axis (O) of the inner cylinder (1), and the inner and outer cylinders (1), A pair of second inclined wall portions (44) having a second inclined surface (43) located on the inner cylinder (1) side toward the other axial end portion (1B), (2B) side of (2), The intermediate cylinder (7) is provided on the inner peripheral side of the intermediate portion in the axial direction so as to sandwich the pair of first inclined wall portions (42) of the inner cylinder (1), and the first inclined surface (41 ) And the second inclined surface (43), the rubber-like elastic body (3) is interposed ,
A cylindrical metal fitting (51) obtained by vulcanizing the first rubber wall (50) between the one end (2A) of the outer cylinder (2) is externally fitted to one end (1A) of the inner cylinder (1). A ring-shaped orifice provided with one liquid chamber (4A) between the first rubber wall (50) and the inner and outer cylinders (1), (2) so as to face the first rubber wall (50). The other liquid chamber (4B) is formed between the orifice forming member (52) and the first rubber wall (50) across the orifice forming member (52). Is formed between the second rubber wall (53) provided on the opposite side,
The orifice-forming member (52) is disposed radially outward from one end of the cylinder (55) and the cylinder (55) that forms the orifice (5) between the orifice-forming member (52) and the inner cylinder (1). A flange (56) that projects, and an outer peripheral portion of the flange (56) is connected to one end (57) of the intermediate tube (7) and one end (2A) side of the outer tube (2). The first rubber wall (50) is set to a convex arcuate cross section on the one liquid chamber (4A) side by being clamped and fixed with a step portion (58) made of a rubber member vulcanized and molded on the peripheral surface. The liquid filled vibration isolator in which the shape of the flange (56) is set so that the longitudinal cross-sectional shape of the flange (56) is a shape along the vertical cross-sectional shape of the first rubber wall (50) . The one liquid chamber (4A) is formed around one end (1A) of the inner cylinder (1) over the entire circumference, and a part of the other liquid chamber (4B) is formed around the inner cylinder (1). The liquid-filled vibration isolator according to claim 1 formed over the entire circumference .   A cylindrical resin material (54) integrally provided with the first inclined wall portion (42) is press-fitted and fitted into the inner tube (1), and the tube is fitted to the end (51A) of the tube fitting (51). The end portion (54A) of the resin-like resin material (54) is received and supported, and a part of the straight cylindrical intermediate tube is recessed inward in the radial direction so that the intermediate tube (7) has the second inclined wall. The liquid-filled vibration isolator according to claim 1 or 2, wherein a portion (44) is formed. The other end (59) of the intermediate cylinder (7) is received in the axial direction by a bent part (60) formed at the other end (2B) of the outer cylinder (2). The liquid-filled vibration isolator according to any one of?

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