JPH0747977B2 - 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 of a rubber elastic body is generally in a predetermined correlation with the static spring characteristic, only the dynamic spring characteristic cannot be softened. Since a large input load is applied to the insulator, it is necessary to select a rubber material with a high static spring constant, so hardening of the dynamic spring characteristics is unavoidable, and vibration isolation performance of the spring insulator. Is equivalent to road noise, etc.
The dynamic spring constant in the rubber elastic body increases as the frequency of the input vibration increases, which is particularly problematic for the input vibration in the relatively high frequency range of up to ~ 300 Hz. The main reason is that high dynamic springs are induced.

(Problem to be Solved) Here, the present invention has been made in the background of the above circumstances, and the problem to be solved is to:
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, the vehicle body side or wheel side having a mounting tubular portion and a flange-shaped mounting plate portion that extends radially outward from one axial end thereof. And a support tubular portion having an inner diameter larger than the outer diameter of the attachment tubular portion of the attachment metal and having an axial length shorter than the attachment tubular portion and the attachment tubular portion. A flange-shaped supporting plate-shaped portion that extends radially outward from one end in the axial direction, and one end side in the axial direction of the coil spring is brought into contact with the supporting plate-shaped portion to form the coil sp And a supporting metal fitting for holding the mounting member, the mounting tubular portion of the mounting metal fitting is concentrically arranged in the supporting tubular portion of the supporting metal fitting, and the plate-shaped portions of both the metallic fixtures are arranged at predetermined intervals in the axial direction. They are spaced apart and face each other, and are concentrically arranged between the plate-shaped portions of the mounting bracket and the support bracket at a predetermined distance radially outward from the mounting tubular portion of the mounting bracket, and have a cylindrical axial direction rubber. An elastic body, and an annular plate-shaped radial rubber elastic body between the mounting fitting and the tubular portion of the support fitting, with a predetermined distance from the mounting plate-like portion of the mounting fitting to the other end side in the axial direction. And the two metal elastic members are integrally connected to each other by the two rubber elastic members, while the mounting metal member, the support metal member, and the two rubber elastic members form a peripheral wall. The specified incompressible fluid is enclosed in the A circumferentially continuous annular fluid chamber to which vibration is applied is formed, and an annular action member having an outer shape substantially corresponding to the inner surface shape of the fluid chamber is formed inside the fluid chamber. In the annular fixing portion that is provided integrally with the portion and extends over the entire circumferential direction,
By fixedly supporting and accommodating and arranging on the outer peripheral side of the fluid chamber, the spring insulator continuously extends in the circumferential direction around the acting member between the inner surface of the fluid chamber and the inner surface of the fluid chamber. It is characterized in that the vibrating portion having a substantially constant gap is formed over the entire circumference.

(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 an annular plate-shaped portion (mounting plate-shaped portion) 12,
A cylindrical portion (mounting cylindrical portion) 14 integrally formed to extend from the inner peripheral edge of the annular plate-shaped portion 12 toward one side in the axial direction.
It consists of and. 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 on the inner side in the radial direction of the cylindrical portion 14 of the mounting fitting 10, and the cylindrical metal fitting 18 is interposed between the cylindrical metal fitting 18 and the cylindrical metal fitting 18. With the cylindrical rubber elastic body 20 mounted,
Is integrally and elastically attached to.
Although not shown, the piston rod of the shock absorber is inserted into and fixed to the tubular metal member 18, whereby the piston rod of the shock absorber is interposed via the rubber elastic body 20. That is, they are elastically connected and supported to the vehicle body side.

On the other hand, an annular plate-shaped portion (supporting plate-shaped portion) 22 is provided outside the cylindrical portion 14 of the mounting member 10 in the radial direction, and a taper extending from the inner peripheral edge portion toward one side in the axial direction. A support fitting 26 including a tubular portion (supporting tubular portion) 24 is positioned substantially concentrically, and the annular plate portion 22 is attached to the annular plate portion 12 of the mounting fitting 10. On the other hand, the inner peripheral surface of the tapered cylindrical portion 24, which faces the axial direction at a predetermined distance,
They are concentrically arranged so as to face the outer peripheral surface of the cylindrical portion 14 of the mounting member 10 at a predetermined distance in the radial direction.

Further, an inner (radial direction) rubber elastic body 28 and an outer (axial direction) rubber elastic body 30 are interposed between the mounting metal fitting 10 and the support metal fitting 26.
The mounting bracket 10 and the support bracket 26 are integrally and elastically coupled by 30.

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 (radial direction) rubber elastic body 28 is formed in a substantially thick cylindrical shape or annular plate shape. Then, on the inner peripheral surface of the inner rubber elastic body 28, an inner caulking metal fitting 34 having a substantially cylindrical shape and having a caulking portion 29 at one axial end thereof is integrally vulcanized and bonded. The support metal fitting is provided on the outer peripheral surface of the inner rubber elastic body 28.
An outer caulking metal fitting 36 having an annular shape substantially corresponding to 26 and having a caulking portion 31 on its outer peripheral edge is integrally vulcanized and adhered.

Further, the outer side (axial direction) rubber elastic body 30 is formed in a substantially large-diameter cylindrical shape, and on both sides in the axial direction,
Upper connecting metal fitting 38 and lower connecting metal fitting in the shape of an annular plate
40 are vulcanized and bonded. In the outer rubber elastic body 30, the inner rubber elastic body is
With respect to 28, the inner peripheral edge portion of the upper connecting metal fitting 38 is crimped and fixed to the inner caulking metal fitting 34, and the outer peripheral edge portion of the lower connecting metal fitting 40 is caulked and fixed to the outer caulking metal fitting 36. Are assembled together by.
That is, the outer rubber elastic body 30 is the annular plate-shaped portion 12 of the mounting bracket 10.
And the annular plate-shaped portion 22 of the support fitting 26 are concentrically interposed and assembled at a predetermined distance radially outward from the cylindrical portion 14 of the mounting fitting 10. Further, the inner rubber elastic body 28 is provided between the cylindrical portion 14 of the mounting member 10 and the tapered tubular portion 24 of the supporting member 26, and the annular plate-shaped portion 12 of the mounting member 10 is provided.
It is inserted and assembled at a predetermined distance from the other end side in the axial direction.

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
Those having a kinematic viscosity of 00 cst or less, more preferably 100 cst or less are desirable, and examples thereof include water, ethylene glycol,
Propylene glycol, other alkylene glycols, low-viscosity polyalkylene glycols, silicone oils, or a mixture thereof are preferably used. The fluid is sealed in the fluid chamber 42, for example, by assembling the inner and outer rubber elastic bodies 28, 30 in a predetermined fluid.

Furthermore, when the inner and outer rubber elastic bodies 28, 30 are assembled in the fluid chamber 42, the action block is formed inside the inner and outer rubber elastic bodies 28, 30.
By accommodating 44, it is arranged in the fluid chamber 42. The action block 44 is formed in an annular shape having an outer peripheral surface shape that is substantially smaller than the inner peripheral surface of the fluid chamber 42 and substantially corresponds to the inner peripheral surface shape of the fluid chamber 42, and its outer peripheral edge portion. In, an annular fixing portion 46 is integrally provided that extends over the entire circumference in the circumferential direction. The action block 44 has its fixing portion 46 superposed on the caulking metal fitting 36 provided on the inner rubber elastic body 28 at the inner peripheral edge of the lower connecting metal fitting 40 fixed to the outer rubber elastic body 30. It is arranged at a predetermined position in the fluid chamber 42 while being fixedly supported by the lower connecting fitting 40 and the caulking fitting 36 by being sandwiched between the surfaces. It should be noted that the material of the action block 44 may be one that does not easily deform and has sufficient corrosion resistance to the enclosed fluid, and for example, metal, resin, or highly elastic rubber is suitable. Can be used for.

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 47 is integrally provided on the contact surface of the mounting metal piece 38 with respect to the mounting metal material 10, and the upper connecting metal piece 38 is attached via the corresponding rubber contact layer 47. Metal fittings 10
It is designed to be abutted and fixed against.

That is, in the spring insulator having such a structure, the coil spring is formed by the inner and outer rubber elastic bodies.
The inner and outer rubber elastic bodies 2 can be elastically supported on the vehicle body side via 28 and 30 by the vehicle body load input from the coil spring under such a device state.
As shown in FIG. 3, the fluid chambers 42 are deformed by deforming 8, 30 so that the action block 44 disposed inside the fluid chambers 42 is located substantially in the center of the fluid chambers 42. It will be positioned. And thereby
In such an apparatus state, the inside of the fluid chamber 42 is narrowed by the action block 44, and as a result, a vibrating portion having a substantially constant gap is provided between the outer surface of the action block 44 and the inner surface of the fluid chamber 42. It is formed over the entire circumference.

Then, in the spring insulator having the above-mentioned structure, under the mounted state, the coil spring causes the vibration to be input between the mounting metal fitting 10 and the supporting metal fitting 26. In the spring insulator, as shown in FIG. 4, a very characteristic frequency characteristic is exhibited in which the dynamic spring constant is substantially constant or decreases as the input vibration frequency increases over a predetermined frequency range. It will happen. In addition, in FIG. 4, the fluid chamber (4
As a comparative example, the results of measuring the frequency characteristics of similar vibration isolation performance of a conventional spring insulator without 2) inside are also shown. In this comparative example, it is clearly recognized that the dynamic spring constant increases with an increase in the input vibration frequency, and the spring insulator of the present example structure is extremely superior to the comparative example. It is possible to exert the anti-vibration effect
It's clear.

By the way, although the details of the action and the principle by which such a reduction effect of the dynamic spring constant is exerted have not been sufficiently clarified yet, vibration is input between the mounting bracket 10 and the supporting bracket 26. At this time, due to the elastic deformation of the inner and outer rubber elastic bodies 28, 30, a predetermined pressure gradient is generated in the vibration action portion formed around the action block 44, and a repeated flow of the fluid is generated therein. The flow resistance due to the inertial force of the fluid generated by the flow of the fluid is the vibration transmission force transmitted through the inner and outer rubber elastic bodies 28, 30 due to the phase difference with respect to the input vibration in the region where the input vibration is equal to or lower than the predetermined frequency. It is thought that this is because it acts to reduce

From this theory, and also from the results of experiments conducted by the present inventor, the frequency range in which such a low dynamic spring effect is exhibited is that the elastic modulus and the action of the inner rubber elastic body 28 and the outer rubber elastic body 30 are large. Depending on the weight (specific gravity) of the block 44, the viscosity of the enclosed fluid, etc., it is possible to tune appropriately by adjusting the thickness and size (width) of the vibration action part, about 500 Hz. It has been confirmed that a low dynamic spring 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 action 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 further, the action block is fixed to the mounting bracket 10 side. You may make it support it.

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 also be effectively applied to a spring insulator that is interposed in 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 suspension spring insulator having a structure according to the present invention, and FIG. 2 is a II-II cross-sectional view of FIG.
Further, FIG. 3 is a cross-sectional explanatory view of relevant parts showing a state at the time of vibration input in the spring insulator shown in FIG. Further, FIG. 4 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. 10: Mounting bracket, 26: Support bracket 28: Inner rubber elastic body, 30: Outer rubber elastic body 42: Fluid chamber, 44: Action 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 on a vehicle body side or a wheel side in a vibration-proof manner, comprising: a mounting cylindrical portion and a flange-shaped mounting plate portion that extends radially outward from one axial end thereof. And a mounting bracket to be mounted on the vehicle body side or the wheel side, and an axial length that has an inner diameter larger than the outer diameter of the mounting tubular portion of the mounting bracket and is shorter than the mounting tubular portion. And a supporting plate-shaped portion having a flange shape extending radially outward from one end in the axial direction of the supporting cylindrical portion, and the one end in the axial direction of the coil spring is abutted to the supporting plate-shaped portion. A support metal fitting that holds the coil springs in contact with each other, and the mounting tubular portion of the mounting metal fitting is concentrically arranged in the supporting tubular portion of the support metal fitting, and the plate-shaped portions of the two metal fittings are axially arranged. Arranged facing each other with a predetermined interval in the direction At the same time, between the plate-shaped portions of the mounting member and the support member, a cylindrical axial rubber elastic body is concentrically provided at a predetermined distance radially outward from the mounting tubular portion of the mounting member, Further, an annular plate-shaped radial rubber elastic body is interposed between the tubular parts of the mounting bracket and the support bracket at a predetermined distance from the mounting plate part of the mounting bracket to the other end side in the axial direction. The two rubber elastic bodies are mounted to integrally connect the two metal fittings, while the mounting metal fitting, the support metal fitting, and the two rubber elastic bodies form a peripheral wall, and a predetermined non-circular wall is formed inside. A compressible fluid is enclosed to form an annular fluid chamber continuous in the circumferential direction in which an input vibration is exerted between the mounting fixture and the support fixture, and the fluid chamber is provided inside the fluid chamber. An annular action member having an outer shape substantially corresponding to the inner surface shape of Integrally provided with the peripheral portion, the fixing portion of the annular extending over the entire circumference,
By accommodating and arranging by being fixedly supported on the outer peripheral wall portion side of the fluid chamber, the spring insulator is continuously mounted in the circumferential direction around the acting member between the fluid chamber and the inner surface of the fluid chamber. A spring insulator for suspension, characterized in that a vibration acting portion having a substantially constant gap extending is formed over the entire circumference.