JP3458321B2 - Liquid filled bush - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid-filled bush mainly used by being incorporated in a suspension of an automobile.

[0002]

2. Description of the Related Art Conventionally, as a bush to be attached to a suspension arm of an automobile, a bush type of a cylindrical type in which an inner cylindrical metal member and an outer cylindrical metal member are connected via a rubber elastic body is used. In addition to the bush, recently, a liquid-filled bush in which a liquid is provided in a liquid chamber provided inside a rubber elastic body between the inner and outer cylinders so as to enhance a damping effect, is relatively often used.

The liquid-filled bush is constructed by providing two liquid chambers on opposite sides of a rubber elastic body which are opposed to each other with a cylindrical inner tubular metal member interposed therebetween, and which are communicated by a communication passage.

By the way, in this type of liquid-filled bush, the communication passage between both liquid chambers is formed by a metal member attached to the intermediate cylinder or the inner cylinder, resulting in high processing cost and the communication passage. The shape of is also limited by the molding method. For example, a metal member is formed into a communication path by press molding in a meandering shape for lengthening the communication path. Depending on the structure, it may not be possible to provide the required spring characteristics (vibration damping characteristics). It is extremely difficult and difficult.

Further, in the conventional liquid enclosing bush of the cylindrical type, in order to obtain a necessary characteristic (damping effect), it is necessary to lengthen the communication passage or increase the volume of both liquid chambers to secure a predetermined pressure receiving area. If so, the outer diameter is increased, the weight is increased, and the cost is increased. Space is limited to prevent interference with peripheral parts, the diameter cannot be increased,
It may be difficult to secure the necessary pressure receiving area.

The present invention has been made in view of the above, and by forming the communication passage for communicating the two internal liquid chambers with the rubber portion, the manufacturing is easy and the cost can be reduced, and it is free. It is possible to provide a liquid-filled bush that can be designed variously and that can easily obtain a target spring characteristic.

[0007]

SUMMARY OF THE INVENTION According to the present invention for solving the above-mentioned problems, a rubber elastic body is interposed between an inner cylinder and an outer cylinder which is arranged outside the inner cylinder with a space therebetween. Has two liquid chambers on opposite sides of the inner cylinder,
A liquid-filled bush in which both liquid chambers are communicated by a communication passage, the cross-section (a cross section perpendicular to the axis) having a substantially rectangular shape or an oval shape, and the liquid chambers on both sides in the longitudinal direction of the cross section. Is provided , and vulcanization is applied to the outer peripheral portion of the rubber elastic body.
It has an attached intermediate cylinder, and this intermediate cylinder is fitted to the outer cylinder.
And having a window in the portion corresponding to both liquid chambers of the intermediate cylinder
In both cases, the outer side surface in the longitudinal direction of the intermediate cylinder is recessed.
Then, a rubber layer is formed on the outside including the recessed portion,
A groove that communicates with both liquid chambers in the rubber layer of the recess
Is provided, the concave grooves you characterized by comprising formed as communicating passages between the both liquid chambers. In addition , the liquid sealing block
In the ash, the intermediate cylinder is press-fitted into the outer cylinder, and the flange end portion of the upper end of the intermediate cylinder is crimped and fixed by the stepped upper end portion of the outer cylinder for crimping the outer cylinder. the upper end of, be those, which are cutout forming portion corresponding to the 4 corners of the substantially rectangular
it can.

[0008]

[Operation] With the liquid-filled bush having the above structure,
Compared to a bush with a circular cross section, the pressure receiving area required for the characteristics can be secured without increasing the size and weight in the direction with less space, and the communication passage between both liquid chambers can be made longer. .

In particular, since the communication passage is formed of a rubber portion, unlike the case where a metal member is pressed, there are few design restrictions, and characteristics such as meandering shape, depth, width, length, etc. It can be freely designed and modified according to the requirements. In addition, the vulcanization molding using the mold makes it possible to form the communication passage easily and with little variation. Therefore, the degree of freedom in design is high, and the target spring characteristic can be easily obtained.

Further, since the communication passage is on the side portion in the longitudinal direction of the cross section and is parallel to the load input direction, the cross sectional shape of the communication passage is not deformed and the spring characteristic is not changed. To be

Further , by constructing as described above,
Since the inner cylinder and the intermediate cylinder, the rubber elastic body, and the outer rubber layer can be integrally vulcanized and molded, and simultaneously the liquid chambers and the communication passages on both sides can be formed, a long communication passage can be easily formed.

When the upper end portion of the outer cylinder for caulking is cut out as in claim 2 , the corner portion is formed even though the upper end portion having a substantially rectangular shape is bent inward and caulked. The caulking ends are not gathered together and deformed into a wrinkle shape, and caulking and fixing can be performed with a substantially uniform force over substantially the entire circumference.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a half cross-sectional explanatory view showing a liquid-filled bush according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line XX in the previous figure. FIG. 3 is a cross-sectional view before the bush main body is press-fitted into the outer cylinder.

In the figure, (1) is an inner cylinder axially fixed to the body frame side of an automobile, (2) is a rubber elastic body, and (3).
Is an outer cylinder attached and fixed to the rear suspension arm, and is fixed directly to the outer peripheral portion of the rubber elastic body (2) at a distance from the inner cylinder (1), or as shown in the figure, the rubber elastic body ( It is arranged via an intermediate cylinder (4) fixed to 2). The inner cylinder (1), the intermediate cylinder ( 4) and the outer cylinder ( 3) are formed to have a rectangular shape or a oval shape (elliptical shape, etc.) whose cross section is substantially rectangular, and have a substantially similar shape. ing. The ratio (B / A) between the vertical dimension (A) and the horizontal dimension (B) in a cross section perpendicular to the normal axis is set to 7/4 or more.

In the case of FIGS. 1 to 3, the inner cylinder (1) and the intermediate cylinder ( 4) are a rubber elastic body (2) interposed between both cylinders.
The inner cylinder (1), the rubber elastic body (2) and the intermediate cylinder (4) are integrally formed as a bush main body (5) by vulcanization and adhesion.

In the rubber elastic body (2), two liquid chambers (6) and (6) are formed as recesses (FIG. 3 in FIG. 3) on both sides of the inner cylinder (1) which are opposed to each other in the longitudinal direction of the cross section. 16) is provided, and windows (7) and (7) corresponding to the recesses (16) and (16) are provided in the intermediate cylinder (4), whereby the recess, that is, the liquid chamber. (6) is open to the outside of the intermediate cylinder (4).

Further, the outer side surface in the longitudinal direction of the intermediate cylinder ( 4) is recessed as shown in FIG. 2, and a rubber layer (2a) having a relatively large thickness forms a seal layer on the outside including the recessed portion. The rubber layer (2a) part (rubber part) is also formed.
A concave groove (FIG. 3) for connecting the two liquid chambers (6) (6) with each other.
Reference numeral 18) is provided therein, and is formed as a communication passage (8) between both liquid chambers (6) and (6) by fitting into the outer cylinder (3).

By thus forming the communication passage (8) in the rubber layer (2a), the depth and width of the concave groove (18) serving as the communication passage within the range of the rubber layer (2a). The length can be set arbitrarily, and in other cases, the damping effect can be enhanced by lengthening the communication passage (8) by bending it in a meandering manner as shown in the figure. The communication passage (8) can be provided only on one side surface of the opposing surfaces in the longitudinal direction or on both surfaces. It can also be provided in a straight line.

Further, in the central portions of the two liquid chambers (6) and (6) (reference numeral 16 in FIG. 8) on both sides facing each other, the inner cylinder (1) side to the outer cylinder (3) are respectively provided. Stoppers (9) (9) projecting toward both sides in the longitudinal direction are provided.

The stopper (9) is formed by covering a stopper metal fitting (9a) integral with the inner cylinder (1) with a stopper rubber portion (2b) integral with the rubber elastic body (2). ) Is provided so as to come into contact with the inner surface of the outer cylinder (3) from the window (7) provided in the intermediate cylinder (4) or close to the inner surface of the outer cylinder (3) with a slight gap. When 2b) elastically contacts the outer cylinder (3), it serves as a stopper. The liquid chamber (6) may be communicated so as to form one chamber around the stopper (9).

Further, one end portion of the intermediate cylinder (4) in the axial direction is extended from the rubber elastic body (2) to be connected to the flange end portion (4).
As a), it is bent outward. Intermediate tube (4)
The other end (4b) is covered with a rubber elastic body (2) and a rubber layer (2a) which is integral with the rubber elastic body (2). To own.

On the other hand, the outer cylinder (3) is formed as an inner flange-shaped locking portion (10) with its lower end bent inward as shown in FIG. 11) is formed as a caulking end and has a slightly larger diameter so that the flange end (4a) can be fitted through the step (12) and opens upward. The upper end (1
In 1), notches (13) are formed in the portions corresponding to the four corners of the substantially rectangular shape so that caulking can be performed easily and surely as described later.

The bush main body (5), which is a vulcanized structure in which the inner cylinder (1) and the intermediate cylinder ( 4) are integrally connected by the rubber elastic body (2) as described above, is made of water. In a liquid tank containing a liquid having an appropriate viscosity, such as a mixed liquid of ethylene glycol and ethylene glycol, a silicon solution, etc., the flange end portion (4a) of the intermediate cylinder (4) is inserted from the upper end opening portion to the outer cylinder (3). ) Is press-fitted to a position where it abuts the step (12), and liquid is sealed in the recess and the recess groove. Further, in this state, take out from the liquid tank, and remove the flange end (4
a) and the upper end (11) of the outer cylinder (3) are connected to the upper end (1
By bending 1) inward, both are integrally caulked and fixed, and the two recesses that are liquid-tightly closed by the outer cylinder (3) and the recessed groove that continues to this are all liquids. Are filled and sealed, and the two liquid chambers (6) and (6) and their communicating passages (8) and (8) are assembled and configured as a liquid sealing bush filled with liquid.

Further, in the above-mentioned caulking fixation, a substantially rectangular shape is formed by providing a notch (13) as shown in a portion corresponding to a corner portion of the upper end portion (11) of the outer cylinder (3). Although the upper end (11) is bent inward and crimped, the upper end does not gather around the corners and is not deformed into a wrinkle. it can.

In addition to the above-mentioned embodiment, as shown in FIGS. 4 and 5, the communicating passage (8) is directly formed in the outer peripheral portion of the rubber elastic body (2) which is the rubber portion simultaneously with the vulcanization molding. You can also In this case, replace the rubber elastic body (2) with the inner cylinder (1).
After vulcanization and molding together with the groove, and forming a recess that will be the liquid chamber (6) and a groove that will be the communication passage (8), on the outer circumference of the rubber elastic body (2), as shown in the figure, (3) may be fitted and fixed by adhesion. It is also possible to form the communication passage (8) in the shape of a hole penetrating the rubber elastic body (2) and opening to both liquid chambers (6) and (6).

The above-mentioned liquid-filled bush is used by being attached to, for example, a rear suspension arm. At this time, since the cross section has a substantially rectangular shape or an oval shape, the same pressure receiving area as that of the conventional circular cross section type bush is secured without increasing the dimension in the direction with a small space margin, and the communication passage (8) Can be set longer than the circular type. That is, since the circumferential length in the case of a substantially rectangular or oval shape is longer than the circumferential length of a circle having the same cross-sectional area, when the pressure receiving area is the same, the communication passage can be long.

In particular, the communication passage (8) has a rubber layer (2a ).
To be formed by parts fraction, unlike the case such as pressing a metal member, less design constraints, serpentine and depth, width, length, freely according to the cross-sectional area or the like on the properties It can be designed and modified. In addition, the vulcanization molding using the mold makes it possible to form the communication passage easily and with little variation. Therefore, the degree of freedom in design is high, and the target spring characteristic can be easily obtained. For example, the peak of vibration damping can be lowered from 300 Hz to about 40 Hz.

Further, since the communication passage is on the side portion in the longitudinal direction of the cross section and is parallel to the load input direction, the cross sectional shape of the communication passage is not deformed and the spring characteristic is not changed. , Durability is also improved.

Further, in the case of the liquid-filled bush provided with the stopper (9), the stopper (9) is displaced by the outer cylinder (3) in the longitudinal direction (lateral direction) of the cross section, which is attenuated by the flow of the liquid.
Since it can be suppressed by abutting against, the dynamic spring constant and static spring constant in the longitudinal direction can be adjusted to be low over a wide range from the low frequency range to the high frequency range. Further, the spring ratio between the longitudinal direction (shearing direction) and the direction orthogonal thereto (compressing direction) can be increased.

[0031]

As described above, according to the present invention, as a liquid-filled bush mainly used by being attached to a suspension arm, the pressure-receiving required for the characteristics can be achieved without increasing the size and weight in the direction with a small space margin. The area can be secured and the communication passage between both liquid chambers can be lengthened. In particular, since the communication passage is formed in the outer rubber layer portion of the intermediate cylinder, there are few design restrictions, and the meandering shape, depth, width, length, etc. are freely designed according to the characteristics, It can also be changed.

Moreover, by vulcanization molding using a mold, it is possible to form a communication passage that is simple and has little variation. Therefore, the degree of freedom in design is high, and the target spring characteristics can be easily obtained.
Bush with target characteristics can be manufactured at low cost.

Further, since the communication passage is on the side portion in the longitudinal direction of the cross section and is parallel to the load input direction, the cross sectional shape of the communication passage is not deformed and the spring characteristic is not changed. The durability is also improved.

[Brief description of drawings]

FIG. 1 is a half cross-sectional explanatory view showing an embodiment of a liquid-filled bush of the present invention.

FIG. 2 is a sectional view taken along line XX of the above.

FIG. 3 is a half sectional view before press-fitting and fitting into an outer cylinder mainly composed of a bush.

FIG. 4 is a half cross-sectional explanatory view showing another embodiment of the liquid sealing bush of the present invention.

FIG. 5 is a cross-sectional view taken along line YY of the above.

[Explanation of symbols]

(1) Inner cylinder (2) Rubber elastic body (2a) Rubber layer (2b) Stopper rubber part (3) Outer cylinder (4) Intermediate tube (4a) Flange end (5) Bush mainly (6) (6) Liquid chamber (7) Window (8) Communication passage (9) Stopper (9a) Stopper bracket (11) Upper end (12) Step (13) Notch (21) Stopper bracket (22) Rubber stopper

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Toriumi 1-17-18 Edobori, Nishi-ku, Osaka City, Osaka Prefecture Toyo Tire & Rubber Co., Ltd. (72) Inventor Akira Suzuki 1-17-18 Edobori, Nishi-ku, Osaka City, Osaka Prefecture No. Toyo Tire & Rubber Co., Ltd. (56) Reference JP-A-3-255239 (JP, A) JP-A-6-109061 (JP, A) JP-A-7-293630 (JP, A) JP-A-1- 255736 (JP, A) Actual flat 6-54938 (JP, U) Actual flat 4-17535 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16F 13/00-13 / 30 B60G 7/00-7/02

Claims (2)

(57) [Claims] 1. A rubber elastic body is interposed between an inner cylinder and an outer cylinder spaced apart from the inner cylinder, and the rubber elastic body is provided at two opposite positions with the inner cylinder interposed therebetween. A liquid-filled bush in which two liquid chambers are provided and these two liquid chambers are communicated by a communication passage, and the cross-section has a substantially rectangular shape or an oval shape, and both liquid solutions are provided on opposite sides in the longitudinal direction of the transverse section. A chamber is provided for the rubber
It has an intermediate tube vulcanized and bonded to the outer periphery of the elastic body.
The intermediate cylinder is fitted to the outer cylinder, and is connected to both liquid chambers of the intermediate cylinder.
The corresponding part has a window and the length of the intermediate tube
The outer side surface in the hand direction is recessed, and the outside including this recessed part
A rubber layer is formed on the
A recessed groove communicating with both liquid chambers is provided, and the recessed groove is formed in the both liquid chambers.
A liquid-filled bush formed as a communication path between the liquid-filled bushes. 2. The intermediate cylinder is press-fitted into the outer cylinder, and the flange end portion of the upper end of the intermediate cylinder is crimped and fixed by the stepped upper end portion of the outer cylinder. 2. The liquid-filled bush according to claim 1 , wherein the upper end portion for is cut out at portions corresponding to the four corners of the substantially rectangular shape.