JPH0730808B2 - Spring insulator for suspension - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a spring insulator for a suspension, and particularly, without reducing the steering stability of a vehicle.
The present invention relates to a spring insulator for suspension, which can be advantageously improved in vibration damping performance.

(Background Art) Conventionally, in a suspension mechanism of an automobile, it is arranged between an axle or arm supporting a wheel and a vehicle body,
Usually, a spring insulator is interposed between the coil spring and the vehicle body-side and wheel-side mounting portions. Such a spring insulator is mounted for the purpose of suppressing vibration transmission to the vehicle body from the wheel side through the coil spring, and for example, for a plate-like metal fitting attached to the vehicle body side or the wheel side, A rubber elastic body is integrally provided on the surface of the coil spring, and one end side in the axial direction of the coil spring is brought into contact with and held by the rubber elastic body.

By the way, in such a spring insulator, in order to suppress the transmission of vibration, it is required to set a soft spring characteristic to enhance the vibration insulation property, while turning, braking, sudden acceleration / deceleration of the vehicle, etc. In order to suppress the change in posture of the vehicle and to secure the steering stability, it is required to set high rigidity and reduce the deformation amount with respect to the load.

Then, the characteristic evaluation of the spring insulator concerning these requirements is carried out with the dynamic elastic characteristic for the vibration insulation of the former and the static elastic characteristic for the steering stability of the latter, respectively.

However, as described above, in the conventional spring insulator in which the vibration-damping property is obtained solely by the elasticity of the rubber elastic body, it is extremely difficult to highly satisfy these vibration insulation properties and steering stability. It was. That is, since the dynamic spring characteristic and the static spring characteristic of the rubber elastic body generally have a predetermined correlation, it is not possible to soften only the dynamic spring characteristic,
In particular, since a large input load is exerted on such a spring insulator, it is necessary to select a rubber material having a high static spring constant, so that hardening of the dynamic spring characteristics is unavoidable, and in the spring insulator. Anti-vibration performance is 100 to 300 equivalent to road noise etc.
Where there is a particular problem with input vibration in a relatively high frequency range of about Hz, the dynamic spring constant of a rubber elastic body is
The main reason is that the input vibration increases as the frequency increases, and in such a high frequency range, a significantly high dynamic spring is caused.

(Problem to be Solved) Here, the present invention has been made in view of the circumstances as described above, and the problem to be solved is as follows.
It is an object of the present invention to provide a spring insulator for a suspension, which can advantageously realize both good vehicle steering stability and excellent vibration damping performance.

(Solution) In order to solve such a problem, according to the present invention, a coil spring that constitutes a suspension of a vehicle is mounted on a vehicle body side or a wheel side attachment portion, and the coil spring is attached to the vehicle body side. Alternatively, in a suspension spring insulator for vibration-proof support on the wheel side, a mounting metal fitting attached to the vehicle body side or the wheel side, and a supporting metal fitting abutting on one axial end of the coil spring to hold the coil spring. To
The coil springs are arranged so as to face each other at a predetermined interval in the axial direction, and a rubber elastic body is interposed between the mounting metal fittings and the supporting metal fittings so that the rubber elastic bodies integrally combine the two metal fittings. On the other hand, at least one fluid chamber, in which at least a part of the wall portion is made of the rubber elastic body and in which a predetermined incompressible fluid is sealed, is formed between the mounting metal fitting and the support metal fitting. Further, the inside of the fluid chamber has an outer shape that substantially corresponds to the shape of the inner peripheral surface of the fluid chamber and is slightly smaller than the inner peripheral surface of the fluid chamber, and is freely movable, and does not easily deform. A characteristic is that a rigid or highly elastic movable member is housed and arranged so that a vibration acting portion having a predetermined gap is formed between the movable member and the fluid chamber inner surface. .

(Examples) Hereinafter, in order to more specifically clarify the present invention, examples of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 show a specific example of the present invention applied to a suspension spring insulator for an automobile. In these figures, 10 is
A mounting bracket, which is composed of an annular plate-shaped portion 12 and a cylindrical portion 14 integrally formed from the inner peripheral edge of the annular plate-shaped portion 12 toward one side in the axial direction. ing. Then, a plurality of mounting bolts 16 are provided on the annular plate-shaped portion 12 of the mounting bracket 10 at predetermined intervals in the circumferential direction, and are fixedly mounted on the vehicle body side by these mounting bolts 16. It is like this.

Further, a cylindrical metal fitting 18 having a cylindrical shape is arranged substantially concentrically inside the cylindrical portion 14 of the mounting metal fitting 10, and is interposed between the cylindrical metal fitting 14 and the cylindrical metal fitting 18. The rubber elastic body 20 having a cylindrical shape is integrally and elastically attached to the attachment fitting 10. And, although not shown, with respect to the tubular fitting 18,
The piston rod of the shock absorber is inserted and fixed, whereby the piston rod of the shock absorber is elastically connected to and supported by the vehicle body side via the rubber elastic body 20. It will be.

On the other hand, on the outer side in the radial direction of the cylindrical portion 14 of the mounting member 10, an annular plate portion 22 and a tapered cylindrical portion 24 extending from the inner peripheral edge portion thereof toward one side in the axial direction. The support metal fitting 26 is positioned substantially concentrically, the annular plate-shaped portion 22 is opposed to the annular plate-shaped portion 12 of the mounting metal fitting 10 at a predetermined distance in the axial direction, And the inner peripheral surface of the tapered cylindrical portion 24, in a state of facing the outer peripheral surface of the cylindrical portion 14 of the mounting member 10 at a predetermined distance in the radial direction,
It is arranged.

Further, an inner rubber elastic body 28 and an outer rubber elastic body 30 are interposed between the mounting metal fitting 10 and the supporting metal fitting 26, and the inner and outer rubber elastic bodies 28, 30 are used to connect the mounting metal fitting 10 and the mounting metal fitting 10 to each other. The support fitting 26 is integrally and elastically connected.

Although not shown in the drawing, one end of the coil spring constituting the suspension mechanism in the axial direction is brought into contact with the lower surface of the annular plate-shaped portion 22 of the support fitting 26 so as to be held. As a result, the coil spring is supported by the inner rubber elastic body 28 and the outer rubber elastic body 30 on the vehicle body side in a vibration-proof manner. A thin rubber layer 33 for holding the spring is provided on the lower surface of the annular plate-shaped portion 22 of the support fitting 26 with which the coil spring is brought into contact.

More specifically, the inner rubber elastic body 28 is formed in a substantially thick cylindrical shape or annular shape. Then, on the inner peripheral surface of the inner rubber elastic body 28, exhibiting a substantially cylindrical shape,
Inner caulking metal fitting having a caulking portion 29 at one axial end thereof
While 34 is integrally vulcanized and bonded, on the outer peripheral surface of the inner rubber elastic body 28, a circular ring shape substantially corresponding to the supporting metal fitting 26 is formed, and a caulking portion 31 is provided on the outer peripheral edge portion thereof. The outer caulking metal fitting 36 provided is integrally vulcanized and adhered.

Further, the outer rubber elastic body 30 is formed in a substantially large-diameter cylindrical shape, and the upper side connecting metal fitting 38 and the lower side connecting metal fitting 40, which have an annular plate shape, are vulcanized and bonded on both sides in the axial direction thereof. Has been. And, in the outer rubber elastic body 30, with respect to the inner rubber elastic body 28,
The inner peripheral edge portion of the upper connecting metal fitting 38 is the inner caulking metal fitting.
The outer peripheral edge portion of the lower connecting metal fitting 40 is caulked and fixed to the outer caulking metal fitting 36, and is integrally assembled.

By assembling the outer rubber elastic body 30 to the inner rubber elastic body 28, an annular closed chamber extending continuously in the circumferential direction is formed between the inner rubber elastic body 28 and the outer rubber elastic body 30. Further, the fluid chamber 42 is formed by enclosing a predetermined incompressible fluid in the sealed chamber. Although not explicitly shown in the drawing, the connecting parts 38 and 40 fixed to the outer rubber elastic body 30 are respectively attached to the mounting parts to the caulking metal parts 34 and 36 fixed to the inner rubber elastic body 28. A seal rubber layer is provided so that the liquid tightness of the fluid chamber 42 can be ensured.

Further, in this case, as the enclosed fluid, in order to ensure sufficient fluidity of the fluid, 1000 cSt or less, preferably 5
00cSt or less, more preferably those having a kinematic viscosity of 100cSt or less, for example, water, ethylene glycol,
Propylene glycol, other alkylene glycols, low-viscosity polyalkylene glycols, silicone oils, or a mixture thereof are preferably used. It should be noted that the encapsulation of the liquid in the fluid chamber 42 is advantageously performed by, for example, assembling the inner and outer rubber elastic bodies 28, 30 in a predetermined fluid.

Furthermore, when the above-mentioned inner and outer rubber elastic bodies 28, 30 are assembled in the fluid chamber 42, a movable block is provided inside thereof.
44 will be inserted and placed. The movable block 44 has an annular shape that substantially corresponds to the shape of the inner peripheral surface of the fluid chamber 42 and has an outer peripheral surface shape that is slightly smaller than the inner peripheral surface. It is placed so that it can move freely by the distance.

The material of the movable block 44 may be one that does not easily deform and has sufficient corrosion resistance to the enclosed fluid, and for example, metal, resin, high elastic rubber, or the like is suitable. Can be used for. And, in particular,
In this embodiment, a synthetic resin material is used, and in a stationary state, as shown in the figure, it is sunk and positioned vertically below the fluid chamber 42.

In the inner rubber elastic body 28 and the outer rubber elastic body 30 integrally assembled in this way, the inner caulking metal fitting 34 fixed to the inner rubber elastic body 28 is the mounting metal fitting.
The upper coupling fitting 38, which is press-fitted into the cylindrical portion 14 of the 10 and fixed to the outer rubber elastic body 30, is the annular plate-shaped portion 12 of the mounting fitting 10.
The lower caulking metal fitting 36 fixed to the inner rubber elastic body 28 is spot-welded to the supporting metal fitting 26 while being attached to the mounting metal fitting 10 in a state of being brought into contact with the outer rubber. It is attached to the supporting metal fitting 26 together with the lower connecting metal fitting 40 fixed to the elastic body 30. And thereby, the mounting bracket 10 and the supporting bracket
The inner rubber elastic body 28 between
However, the outer rubber elastic body 30 is interposed between the axially opposite surfaces, so that both metal fittings 1
0 and 26 are elastically connected by the inner and outer rubber elastic bodies 28 and 30. In addition, the upper connection fitting
An abutting rubber layer 46 is integrally provided on the contact surface of the mounting metal 10 with the mounting metal fitting 10, and the upper connecting metal fitting 38 is attached via the corresponding rubber contact layer 46. Metal fittings 10
It is designed to be abutted and fixed against.

That is, in the spring insulator having such a structure, the input load from the coil spring is supported by the inner rubber elastic body 28 and the outer rubber elastic body 30, while the vibration from the coil spring is generated. When the input causes a periodic relative displacement between the mounting metal fitting 10 and the support metal fitting 26, the inner and outer rubber elastic bodies 28, 30 are elastically deformed to deform the fluid chamber 42. As a result, the fluid enclosed in the fluid flow is generated, and based on the fluid flow, the dynamic spring constant of the spring insulator is changed as shown in FIG.
The characteristic effect of being lowered over a predetermined frequency range is exhibited. In addition, in FIG. 3, the result of measuring the frequency characteristic of the similar vibration isolation performance is also shown as a comparative example for the spring insulator having the conventional structure without the fluid chamber (42) inside.

By the way, the details of the action and the principle by which such an effect is exhibited are not yet clear, but first, when vibration is input between the mounting member 10 and the supporting member 26, As shown in the figure, the flow of the fluid generated in the fluid chamber 42 causes the movable block 44 to move.
It is levitated in the fluid chamber 42, whereby a fluid is made to exist around the movable block 44 and the inner surface of the fluid chamber 42, and a fluid action region as a vibration action portion is formed therein. It is considered to be a thing. Then, the elastic deformation of the inner and outer rubber elastic bodies 28, 30 due to the vibration input causes a fluid flow in the fluid action region, and based on the resonance action of the fluid, the low dynamic spring as described above is generated. It is speculated that the effect can be exerted.

As a result of experiments and studies conducted by the present inventor on the vibration isolation characteristics of the spring insulator having the above-described structure, as shown in FIG. 3, a predetermined frequency range from low frequency to high frequency is obtained. It was confirmed that while the effect of decreasing the dynamic spring constant of the spring insulator is exerted over the range, the effect of increasing the dynamic spring constant is exerted conversely in the higher frequency region beyond this region. However, from the point that this is apparently related to the resonance phenomenon of the fluid, the above conjecture is convinced to some extent.

Further, the frequency range in which such a low dynamic spring effect is exerted depends on the elasticity of the inner and outer rubber elastic bodies 28, 30, the weight (specific gravity) of the movable block 44, the viscosity of the enclosed fluid, and the like. It is possible to tune appropriately by adjusting the thickness and its size (width).
It has been confirmed by the present inventor that a low dynamic spring down to about 0 Hz can be easily achieved.

Therefore, in such a spring insulator, a low dynamic spring can be advantageously achieved over an extremely wide frequency range, whereby vehicle noise such as road noise and vibration can be reduced extremely effectively. Therefore, an excellent riding comfort can be realized.

Further, the low dynamic spring effect due to the enclosed fluid as described above can be exerted based on the flow of the fluid at the time of vibration input, and can contribute only to the improvement of the dynamic spring characteristic against the input vibration in the high frequency range. Therefore, it is possible to set a sufficient static spring rigidity for the inner and outer rubber elastic bodies 28, 30, and therefore, good vehicle steering stability can be sufficiently ensured.

Although the embodiments of the present invention have been described in detail above, these are literal examples, and the present invention should not be construed as being limited to such specific examples.

For example, in the spring insulator in the embodiment, the annular fluid chamber 42 continuous in the circumferential direction was provided, but it is not always necessary to form the fluid chamber continuous in the circumferential direction, and a plurality of independent fluids may be formed. It is also possible to provide a chamber.

Further, the shape of the movable block 44 accommodated and arranged in such a fluid chamber is appropriately set according to the shape of the inner peripheral surface of the fluid chamber, and is substantially the same as or smaller than the enclosed fluid. You may make it use what has specific gravity.

Furthermore, in the spring insulator in the above-described embodiment, the central portion thereof is provided with the upper support portion to which the shock absorber arranged inside the coil spring is attached, but the present invention is such an upper support. It is needless to say that the present invention can be advantageously applied to a device having no part, that is, a device which functions only as an insulator of the coil spring when the coil spring and the shock absorber are separately arranged. .

Then, when it is not necessary to provide such a shock absorber mounting portion, it is not necessary to provide the mounting member 10 with the cylindrical portion 14, and the mounting member 10 and the supporting metal member 26 are each formed of a plate-shaped body. It is also possible.

Further, it goes without saying that the present invention can be effectively applied to a spring insulator that is provided at a mounting portion of the coil spring on the wheel side.

In addition, although not enumerated one by one, the present invention can be carried out in a mode in which various alterations, modifications, improvements, etc. are added based on the knowledge of those skilled in the art. It goes without saying that all of them are included in the scope of the present invention without departing from the spirit of the above.

(Effects of the Invention) As is clear from the above description, in the spring insulator for suspension according to the present invention, the fluid flow action in the vibration acting portion that occurs when the vibration is input between the mounting metal member and the support metal member. Or, based on the resonance action, the effect of reducing the dynamic spring constant in the high frequency region can be advantageously exerted without causing a significant decrease in the static spring constant, and therefore, the steering stability of the vehicle can be sufficiently improved. A spring insulator that can exhibit excellent vibration damping performance while being satisfied can be advantageously provided.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a specific example of a spring insulator for suspension having a structure according to the present invention, and FIG. 2 is a II-II cross-sectional view in FIG.
Further, FIG. 3 is a graph showing the results of measuring the frequency characteristics of the vibration isolation performance of the spring insulator having the structure shown in FIG. 1 together with the comparative example. Further, FIG. 4 is a cross-sectional explanatory view of a main part showing a state at the time of inputting vibration in the spring insulator shown in FIG. 10: Mounting bracket, 26: Support bracket 28: Inner rubber elastic body, 30: Outer rubber elastic body 42: Fluid chamber, 44: Movable block

Claims (1)

[Claims] 1. A vehicle-side or wheel-side mounting portion of a coil spring that constitutes a vehicle suspension,
A suspension spring insulator for supporting the coil spring in a vibration-proof manner on the vehicle body side or the wheel side, wherein the attachment metal fitting is attached to the vehicle body side or the wheel side, and is brought into contact with one end side in the axial direction of the coil spring. The supporting metal fittings for holding the coil springs are arranged so as to face each other at a predetermined distance in the axial direction of the coil springs, and a rubber elastic body is interposed between the mounting metal fittings and the supporting metal fittings to provide the rubber elasticity. While the two metal fittings are integrally connected by a body, at least a part of the wall portion is formed of the rubber elastic body between the mounting metal fitting and the support metal fitting, and a predetermined incompressible fluid is At least one sealed fluid chamber is formed, and further, inside the fluid chamber, the inner circumferential surface of the fluid chamber substantially corresponds to the shape of the inner circumferential surface of the fluid chamber. A hard or highly elastic movable member that does not easily deform and that has a shape smaller than that of the movable member and that is freely movable is accommodated and arranged, and a predetermined gap is provided between the movable member and the inner surface of the fluid chamber. A spring insulator for a suspension characterized in that a vibration acting part of the above is formed.