JP2002337527A - Suspension bush assembly structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension bush assembly structure capable of excellently heightening the durability of a rubber elastic body while ensuring the excellent ride quality of a vehicle. SOLUTION: A pair of outer cylindrical metal halves (24a and 24b) of half- split cylindrical shape are symmetrically arranged facing each other with an inner cylindrical metal piece 26 therebetween, and connected to each other by a rubber elastic body 28, an axially piercing recessed part 30 in the direction orthogonal to the connecting direction and a bush 20 formed on both sides thereof with the inner cylindrical metal piece 26 therebetween are press-fitted to an arm eye part 22 so that the bush axial direction is perpendicular, and the bush 20 is subjected to high compression with the compression ratio of 30-40%, and the spring characteristic of the bush in the connecting direction is non-linear.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly structure of a suspension bush, and more particularly, to a suspension arm of a vehicle suspension, which is press-fitted into a cylindrical arm eye portion and mounted so that a bush axis direction is vertical. And a vertically mounted suspension bush assembly structure.

[0002]

2. Description of the Related Art As one of suspensions of vehicles such as automobiles, for example, as shown in Japanese Utility Model Laid-Open No. 61-91408 and Japanese Patent Application Laid-Open No. 6-106931, a carrier for rotatably supporting wheels is provided. While the outer end is pivotally attached to the lower end of such a carrier, at least in the vehicle longitudinal direction, two inner ends provided separately from each other are pivotally supported on the vehicle body via an elastic joint. There is known a strut type having an L-shaped lower arm. Of the two inner ends of the L-shaped lower arm in such a type of suspension, an elastic joint provided at the inner end on the vehicle rear side with respect to a center axis extending in the vertical direction (vertical direction) of the vehicle. And an inner cylindrical fitting fixed concentrically to the vehicle body and an arm eye portion extending concentrically with respect to such an inner cylindrical fitting and forming an inner end of the lower arm on the vehicle rear side. A vertically mounted rubber bush (suspension bush) comprising a fixed outer cylinder fitting and a rubber elastic body interposed between the inner and outer cylinder fittings and connecting the inner and outer cylinder fittings. Is well known in the art.

[0003] In the strut type suspension employing such a vertically mounted bush assembly structure, each of the inner ends of the L-shaped lower arm has a center axis extending in the vehicle longitudinal direction. The front-back compliance of the suspension can be increased as compared with the structure in which each of the suspensions can be pivotally supported on the vehicle body through the elastic joints, thereby improving the ride comfort of the vehicle. Although it is known, in order to further improve the riding comfort, a rubber elastic body of a cylindrical shape inserted between an inner cylinder fitting and an outer cylinder fitting in such a rubber bush having a vertical structure is known. Then, cavities (curves) penetrating in the axial direction of the bush are provided on both sides of the inner cylindrical fitting so as to sandwich the inner cylindrical metal fitting. Structure to the vehicle longitudinal movement is facilitated Ya) has also been studied.

[0004] Incidentally, even in a suspension employing such a suspension bush structure, since the guarantee as a car in recent years has become strict, a rubber elastic body against a relatively large movement of the inner cylinder with respect to the outer cylinder is required. In terms of durability, it has become difficult to satisfy the requirements sufficiently.

In other words, when a relatively large displacement occurs in the inner cylindrical member due to a load acting between the outer cylindrical member and the inner cylindrical member, the bushing is provided at the corner of the bulging portion provided on the rubber elastic body. A large tensile force is applied, and a defect such as a crack is generated in the rubber elastic body by such a tensile force, and the durability is reduced.

Accordingly, in order to satisfy the durability of the rubber bush, especially the rubber elastic body in a state where the higher required characteristics for the suspension are satisfied, the rubber volume such as the rubber elastic body in the conventional rubber bush is required.
It was difficult, therefore, by increasing the rubber volume of such a rubber elastic body and suppressing the tensile force from acting on the corners of the hollow part due to the large displacement of the inner cylindrical fitting, It is conceivable to secure the durability, but such an increase in rubber volume directly leads to an increase in cost, and the increase in the bush size increases the weight and the design of the suspension arm. Causes problems such as adverse effects.

[0007]

The present invention has been made in view of such circumstances, and a problem to be solved is that even if the demand for guarantee increases, the vehicle volume can be increased without increasing the rubber volume. It is an object of the present invention to provide a suspension bush assembly structure capable of satisfactorily ensuring the riding comfort of the vehicle and improving the durability of the rubber elastic body.

[0008]

According to the present invention, in order to solve such a problem, a suspension arm of a vehicle suspension is press-fitted into a cylindrical arm eye portion so that a bush axis direction becomes a vertical direction. A vertically mounted suspension bushing assembly structure is attached, and a pair of half-cylindrical outer cylinder fittings are symmetrically opposed to each other with a predetermined inner cylinder fitting therebetween, and the pair of outer cylinder fittings is provided. The half body and the inner cylinder are connected to each other by a rubber elastic body, and in the direction perpendicular to the connecting direction, a piercing portion that penetrates in the axial direction is formed on both sides of the inner cylinder by interposing the inner cylinder. Using a bush having the following structure, press-fitting the bush into the arm eye so that the bush axis direction is vertical,
Apply a high compression rate of 30-40% to the bush,
The gist of the present invention is a suspension bush assembly structure wherein the spring characteristics of the bush in the connection direction are non-linear.

In the suspension bush assembly structure according to the present invention, as the vertically arranged suspension bush, the outer cylinder is not formed into an integral cylindrical shape, but is formed into a half-split shape. A bush having a structure in which a pair of bulges is formed on both sides of the inner cylindrical fitting at the abutting portion of the half of the outer cylindrical fitting is press-fitted into the cylindrical arm eye of the suspension arm. At least, a high compression of 30 to 40% is applied so that the spring characteristics in the connection direction by the rubber elastic body of the inner and outer cylinders are configured to be non-linear. The constant becomes harder (higher), so that the ratio of the static spring constant in such a connecting direction and the opposing direction of the bulge portion perpendicular to the connecting direction is made higher than that of the conventional bush. And than was decided that may for listening, and thereby to improve the steering stability, it became a get advantageous aim.

In addition, since such a bush is pressed into the arm eye portion at a high compression ratio of 30 to 40%, the inner and outer cylinders are relatively displaced by the action of an external load. Also, the bush (rubber elastic)
Since the compression component is dominantly applied and is always maintained in a state where the compression component is applied, the tensile stress does not act on the rubber elastic body, and it can greatly contribute to the improvement of the durability. It becomes.

According to a preferred embodiment of the suspension bush mounting structure according to the present invention,
The bush is located in the load input direction at the arm eye portion corresponding to the movement of the wheel attached to the suspension arm in the vehicle front-rear direction, and the bush is located between the outer cylinder half and the inner cylinder. The arm eye portion is press-fitted so that the connecting direction is located in a direction perpendicular to the load input direction. By adopting such a bush press-fitting and arrangement structure, in the direction in which the tire (wheel) is smoothly moved in the front-rear direction, the spring of the bush is softened, so that the tire also moves smoothly. While the ride comfort can be improved, the direction in which the tires are difficult to move is perpendicular to the direction in which such tires are easy to move. By making the static spring constant harder, excellent ride comfort and steering stability can be achieved at the same time, and it can be realized effectively.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, typical embodiments according to the present invention will be described in detail with reference to the drawings.

First, FIG. 1 shows a plan view of an L-shaped lower arm which is a suspension arm used for a front suspension of a vehicle, and FIG.
Such a lower arm is shown in a form (front view) viewed from the inside to the outside (tire side) of the vehicle. In these drawings, one of the two suspension bushes is shown in a half cut sectional view.

In these figures, a ball joint 12 is disposed at the outer end of the L-shaped lower arm 10 on the vehicle, and the ball joint 12 is connected to a carrier (shown in FIG. ) Is attached to the wheels (tires) 14.
Of the two inner end portions of the lower arm 10 which are spaced apart from each other in the vehicle front-rear direction, the arm eye portion 16 which is located on the vehicle front side has a horizontal rubber bush whose bush axis direction is horizontal. On the other inside end of the lower arm 10 located on the rear side of the vehicle, a rubber bush 20 is provided as a suspension bush so that the axial direction of the bush is vertical. Then, the rubber bush 18 and the rubber bush 2 which are placed horizontally and vertically are pressed into the arm eye portion 22 and attached.
With 0, the lower arm 10 is pivotally supported on the vehicle body.

Under such circumstances, such a lower arm 10
Of the two suspension bushes attached to the vehicle, a vertically arranged rubber bush 20 is configured in the structure shown in FIGS. 3 and 4 to solve the above-mentioned problem of the present invention, and is arranged in the arrangement shown in FIG. In the configuration,
The arm eye portion 22 is press-fitted.

In short, as is apparent from FIGS. 3 and 4, the rubber bush 20 provides an outer cylinder fitting 24 which becomes a cylindrical body when the corresponding ends are brought into contact with each other. Hardware halves 24a, 24b
, Inner cylinder fitting 26, and a pair of outer cylinder fitting halves 24
a, elastic body 28 for connecting inner tube fitting 26 to inner tube fitting 26
In a state in which a pair of outer cylinder metal halves 24a and 24b are symmetrically opposed and arranged on both sides of the inner cylinder metal 26, they are connected by a rubber elastic body 28 to form an integral body. It has a simple structure. Further, the pair of outer cylinder metal halves 24a and 24b and the inner cylinder metal 26
In the direction orthogonal to the connecting direction, in other words, at the abutting portions located on both sides of the pair of outer cylinder metal halves 24a and 24b on both sides of the inner cylinder metal 26, the burrs 30 penetrate in the axial direction of the bush. It is formed as a void.

Incidentally, such a pair of outer cylinder metal halves 24 is provided.
As is well known, the rubber bush 20 having an integral structure formed by connecting the inner and outer metal fittings 26 and the inner cylindrical fitting 26 with a rubber elastic body 28 has a well-known structure. In a state where the pair of outer cylinder metal halves 24a, 24b and the inner cylinder metal fitting 26 are arranged at a position, a predetermined rubber material is supplied, and the rubber elastic body 28 is vulcanized to form an integrated body. It can be easily manufactured according to various known methods such as a method of obtaining a vulcanized molded product.

The rubber bush 2 having the structure as described above
0, as shown in FIG.
Abut the corresponding circumferential ends of 24b
Under the radially compressed state,
Inner end on the vehicle rear side of the two inner ends of the arm 10
Press-fit into the arm eye 22 provided in the
In the present invention, in particular,
In such press-fitting, the compression ratio of the rubber elastic body 28 is 3
Press-fitting is performed so as to be 0 to 40%.
You. Specifically, as shown in FIG.
How to connect the inner and outer tube fittings 24 and 26 in the bush 20
The distance between the inner and outer tube fittings 24 and 26 in the direction₀ And figure
As shown in FIG. 5, the rubber bush 20
The distance in the connecting direction of the inner and outer tube fittings 24 and 26 is H₁ When
Then, [(H₀ -H₁ ) / H ₀ ] × 100
Compression ratio (%) within the range of 30-40%
The rubber bush 20 is pressed into the arm eye 22
This allows the two bead sections 30,
In the opposing direction of 30 (the direction of the central axis 32),
While such softness is ensured, such
The direction perpendicular to the opposing direction of the parts 30, 30, in other words
In the connecting direction of the inner and outer cylindrical fittings 24 and 26 by the elastic body 28.
In the following, the spring characteristics are made to be non-linear
is there.

Here, generally, when compression is applied to rubber, a linear spring characteristic (load-deflection characteristic) is initially displayed, but when compression is further applied, such spring characteristic becomes non-linear. Therefore, in the present invention, the non-linear characteristic developed when the compression ratio is 30% or more is used. Further, when the compression ratio becomes too high, the spring itself becomes In addition to the problem of being too hard, a crack or the like is generated at the bonded end of the rubber elastic body 28, which causes a problem of reducing durability. Therefore, the upper limit of such a compressibility is set to 40%. It was decided. It should be noted that such a high compression of 30 to 40% with respect to the rubber elastic body 28 can be obtained for the first time by dividing the outer tube fitting 24 into two parts and forming a pair of half-cylinder outer tube fitting members 24a and 24b. In the case of a bush using an integral outer cylinder, such a high compression is applied, so that the outer cylinder can be cracked or the adhesive applied to the inner surface of the outer cylinder can be realized. This causes problems such as cracking of the coating film and cracking of the rubber.

By applying such a high compression of 30 to 40% to the rubber elastic body 28 of the rubber bush 20, the static spring in the connecting direction of the inner and outer cylindrical fittings 24 and 26 of the rubber bush 20 becomes harder (spring constant). The connection direction and the central axis direction 32
Thus, the ratio of the static spring constant to the above can be increased, and thus, as will be described later, it is possible to advantageously achieve both riding comfort and steering stability.

In addition, due to such high compression, a compression component is always applied to the rubber elastic body 28 of the rubber bush 20, so that the inner and outer cylindrical fittings 24, 26 are provided.
Even if is relatively displaced, no tensile stress is applied, so that an improvement in durability can be advantageously achieved.

When the rubber bush 20 is press-fitted into the arm eye portion 22 of the lower arm 10 and is mounted under high compression as described above, the rubber bush 20 is placed in the opposite direction (the center of the The direction of the shaft 32) is pressed into the arm eye portion 22 and arranged so as to be the easiest direction to smoothly move the wheel (tire) 14 in the vehicle longitudinal direction. More specifically, as shown in FIG. 1, the rubber bush 22 includes a wheel (tire) 1 in which a facing direction of the burrs 30, 30 is attached to the lower arm 10.
4 is pressed into the arm eye portion 22 so as to be positioned in the load input direction of the arm eye portion 22 corresponding to the movement in the vehicle front-rear direction and the bush axis direction is vertical. (Tire) 14 is easily and smoothly moved in the front-rear direction of the vehicle, thereby improving ride comfort.

As described above, in the rubber bush 20,
The direction of the central axis 32, which is the direction in which the two guiding parts 30, 30 are opposed to each other, is arranged in the direction in which the wheel (tire) 14 is easy to move, so that the connecting direction of the inner and outer cylindrical fittings 24, 26 of the rubber bush 20 is changed. , Such a central shaft 3
The tire is positioned in a direction that is difficult to move, which is a direction perpendicular to the second direction, and
A high compression of 30 to 40% is applied to a portion of the rubber elastic body 28 connecting the inner and outer cylindrical metal fittings 24, 26, so that a vehicle left-right direction corresponding to the connecting direction / the direction of the central shaft 32 is provided. / The ratio of the static spring constant in the front-back direction can be increased, and the ride comfort and steering stability are improved.
Both can be advantageously implemented.

The direction of the center axis 32 of the rubber bush 20 when the rubber bush 20 is press-fitted into the arm eye portion (22) of the suspension arm (10) is not fixed, but depends on the structure of the vehicle and the structure of the suspension arm (10). The suspension arm (10) to which such a tire (14) is attached is changed so that the tire (14) changes easily between the left-right axis and the front-rear axis shown in FIG. Of the load applied to the arm eye portion 22 through the two bushing portions 3 of the rubber bush 20 in the input direction of the load acting in response to the movement of the tire (14) in the vehicle longitudinal direction.
0 and 30 are arranged so as to face each other. Therefore, the direction of the center shaft 32 in the rubber bush 20 does not always coincide with the front-rear direction of the vehicle. Here, the angle α formed by the center shaft 32 with respect to the left and right axes is about 20 °. Press-fitted and arranged.

In the rubber bush 20,
As for the size of the two opposite burrs 30, 30,
As shown in FIG. 5, press fitting into the arm eye portion 22,
Under the compression state,
The selection angle is appropriately selected according to the required softness of the spring. Generally, the angle of the bend: β, in other words, the spread angle of the bend portion 30 viewed from the bush axis is 50 ° to 100 °. Degree is adopted, and in the illustrated example, it is about 90 degrees.

By the way, as described above, the lower arm 10
An excellent feature of the rubber bush 20 in a compressed state as shown in FIG. 5 which is press-fitted and attached to the arm eye portion 22 is that an integral cylindrical body is used as the outer cylinder, and the inner cylinder is combined with a rubber elastic body. 6 and 7 in comparison with a conventional rubber bush of the structure in which the same size bulges are provided facing each other on both sides of the inner cylindrical metal fitting. It is easy to understand.

That is, FIG. 6 shows a load-deflection characteristic when a load is applied between the inner and outer cylinders in the direction in which the inner and outer cylinders are connected by the rubber elastic body, and FIG. In the center axis direction, it is a graph showing the load-deflection characteristics when a load is applied between the inner cylinder and the outer cylinder, in any measurement, while fixing the inner cylinder, while the outer cylinder This method employs a method of recording the degree of bending (displacement) of the outer cylinder with a recorder by applying a load. The bevel angle (β) of the bush of the present invention is about 90 ° (after press-fitting), and in the conventional bush, the beveled portion has a 90 ° angle when viewed from the bush axis. Is provided. And in those figures, the solid line shows the characteristics of the bush of the present invention, and the broken line shows the characteristics of the conventional bush.

6, the bush of the present invention shows a larger static spring constant than the conventional bush in the connection direction of the inner and outer cylindrical fittings in FIG. As shown in FIG. 7, in a certain direction of the shaft, the bush of the present invention and the conventional bush indicate that the static spring constant (inclination of direct static) is substantially the same. Thus, in the bush of the present invention, it can be understood that the ratio of the static spring constant in the connecting direction of the inner and outer cylindrical metal fittings / in the direction of the cutting shaft can be set large.

While a representative embodiment of the present invention has been described above in detail, it is merely an example, and the present invention is to be interpreted in a limited manner by the specific description in such an embodiment. It should be understood that this is not the case.

For example, the shape and structure of the suspension arm, specifically, the shape and structure of the lower arm 10, the mounting structure of the wheels at the outer end thereof, and the mounting structure to the vehicle body via the rubber bush 18 are described. Various well-known structures and configurations are appropriately adopted.

Further, even in the case of the rubber bush 20 of the vertical type, the outer cylindrical member is constituted by a pair of half-cylindrical cylindrical halves, and is opposed to both sides of the inner cylindrical member. As long as the rubber bush has a structure in which two bulges are formed as described above, a bush having a structure in which various modifications are made can be used at all.

In any case, the present invention is based on the knowledge of those skilled in the art without departing from the spirit of the present invention.
It is needless to say that various changes, modifications, improvements, and the like can be made, and all such embodiments fall within the scope of the present invention.

[0033]

As is apparent from the above description, according to the suspension bush assembling structure according to the present invention, a vertically arranged suspension bush in which the outer cylinder fitting is constituted by a pair of half-cylindrical halves is used. As a result, such a suspension bush can be pressed into the arm eye portion of the suspension arm at a high compression ratio of 30 to 40% and arranged, whereby the compression component always acts on the rubber elastic body. Therefore, even if the inner and outer cylindrical fittings are displaced relative to each other, no tensile stress is applied to the rubber elastic body, so that the durability thereof can be remarkably increased. Since the compression is applied, the static spring constant of the suspension bush and thus the rubber elastic body can be increased with respect to the movement in the left and right direction of the vehicle. By occupying become large ratio of the vehicle lateral direction and the vehicle longitudinal direction of the static spring constant, allowed improving the steering stability, it become a further may also achieve improved ride quality.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view (partially cut away) showing an L-shaped lower arm in a strut type suspension which is one of vehicle suspensions.

FIG. 2 is an explanatory front view (partially cut away) of the L-shaped lower arm shown in FIG. 1;

FIG. 3 is an explanatory plan view showing an example of a rubber bush pressed into an arm eye portion provided at a vehicle rear side portion of an inner end portion of the lower arm shown in FIG. 1;

FIG. 4 is an explanatory cross-sectional view of the rubber bush shown in FIG. 3 along AA.

FIG. 5 is an explanatory plan view showing a press-fit and compression mode of the rubber bush shown in FIG. 3;

FIG. 6 is a graph showing a load-deflection characteristic in a connecting direction of the inner and outer cylindrical fittings in comparison between the bush of the present invention and the conventional bush.

FIG. 7 is a graph showing the load-deflection characteristics in the direction of the center axis of the hollow in comparison with the bush of the present invention and the conventional bush.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Lower arm 12 Ball joint 14 Wheel (tire) 16, 22 Arm eye part 18, 20 Rubber bush 24a, b Half outer cylinder metal fitting 26 Inner cylinder metal fitting 28 Rubber elastic body 30 Straightening part 32 Straightening central axis

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tatsuya Ito 3-1, Higashi 3-chome, Komaki-shi, Aichi F-term (reference) in Tokai Rubber Industries, Ltd. 3D001 AA17 BA02 DA08 DA12 3J048 AA01 AC01 BA04 BA19 BB03 DA06 EA15 3J059 AA06 AB11 AC01 AD01 AE05 BA64 BA66 BC06 BD05 BD06 CA03 CB02 EA14 GA02

Claims (2)

[Claims] 1. A vertically-divided suspension bush assembly structure which is press-fitted into a cylindrical arm eye portion of a suspension arm of a vehicle suspension and is mounted so that a bush axis direction is vertical. A pair of shaped outer cylinder metal halves are symmetrically opposed to each other with a predetermined inner cylinder metal, and the pair of outer cylinder metal halves and the inner cylinder metal are connected with a rubber elastic body, respectively. In a direction perpendicular to the connecting direction, a bushing having a structure in which a burring portion penetrating in the axial direction is formed on both sides thereof with the inner cylinder fitting in between is used. So that the bush is press-fitted into the arm eye portion, and the bush is subjected to high compression with a compression ratio of 30 to 40%. Suspension bushing assembly structure spring characteristic, characterized in that as a nonlinear in direction. 2. The bushing according to claim 2, wherein the bushing is positioned in a load input direction at the arm eye corresponding to a movement of a wheel attached to the suspension arm in a vehicle longitudinal direction. 2. The suspension bush assembly structure according to claim 1, wherein the arm bushing is press-fitted into the arm eye portion so that a connecting direction of the inner cylinder and the inner cylinder is located in a direction perpendicular to the load input direction. 3.