JP4580089B2 - Elastic bush and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an elastic bush that blocks vibration and noise, and in particular, a member mount that is provided between a suspension member and a vehicle body in order to block vibration from an undercarriage from being transmitted to the vehicle body in an automobile. It is related with a suitable elastic bush.
[0002]
[Prior art]
In vehicles such as automobiles, the following structure is particularly known as a front suspension. That is, one end of the transverse link for suspending the wheel is slidably connected to the wheel by a ball joint or the like, and the other end is connected to the pair of left and right transverse links via a vibration isolator. Suspension members are provided. The vehicle body is mounted on the suspension member via a member mount. Usually, the suspension member has a rectangular frame shape or an X shape, and the member mounts are provided at the four corners, respectively.
[0003]
This member mount is press-fitted into a member collar fixed to the suspension member by welding or the like. As shown in FIG. 4, the metal outer cylinder 1 and the inner peripheral side of the outer cylinder 1 are substantially parallel to each other. Are substantially vulcanized and bonded to the inner cylinder 2 made of metal, the inner circumferential surface of the outer cylinder 1 and the outer circumferential surface of the inner cylinder 2, respectively, and elastically connecting the outer cylinder 1 and the inner cylinder 2 to each other. And an elastic body 3 in the form of a ring.
[0004]
The outer cylinder 1 of the member mount is a flange portion 1A whose one end is bent outward so as to be positioned when it is press-fitted into the member collar which is the attached body 4. The elastic protrusion 3A provided on the outer side in the axial direction of the flange portion 1 is provided in consideration of the contact of a stopper (not shown) for regulating the axial displacement.
[0005]
The other end of the outer cylinder 1 is a flange portion 1B that is bent inward, and serves as a reinforcing metal core for an elastic protrusion 3B provided on the outer side in the axial direction. The elastic protrusion 3B is also provided in consideration of axial displacement restriction.
[0006]
In such assembly of the member mount, the member collar is arranged so that the opening is on the lower side due to restrictions on the vehicle body structure, so that the outer cylinder is press-fitted from below to be fixed. On the other hand, the body shaft that is the vibration receiving portion is inserted into the inner cylinder of the press-fitted member mount, and a nut or the like is screwed into the male thread portion provided at the tip of the connection shaft, so that the member mount The vehicle body is connected and fixed.
[0007]
[Problems to be solved by the invention]
However, since the outer cylinder 1 of the member mount to the member collar (attached body 4) is inserted from the flange portion 1B side bent to the inside and pushed into the flange portion 1A bent to the outside, it is pushed in. The substantially entire outer periphery of the outer cylinder 1 is in pressure contact with the inner peripheral surface of the member collar (attached body 4), which requires a large pressure input.
[0008]
Further, if the radius of the bent portion of the flange portion 1A is large, the end of the member collar (attached body 4) comes into contact with the bent portion before contacting the flat portion of the flange portion 1A. A larger pressure input is required for completion. The necessity of such a large pressure input is a heavy work load due to the limitation of the work space around the member mount.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is to provide an elastic bushing that does not require a large pressure input when an elastic bushing such as a member mount is press-fitted into an attachment body such as a member collar, and a method for manufacturing the same.
[0010]
[Means for Solving the Problems]
The present invention has been made to solve the above problems, and the first of the gist thereof is an outer cylinder, an inner cylinder disposed on the inner peripheral side of the outer cylinder, and an inner peripheral surface of the outer cylinder. A bush composed of an elastic body fixed between the outer peripheral surface of the inner cylinder and elastically connecting the outer cylinder and the inner cylinder, and when the outer peripheral surface of the outer cylinder is press-fitted into the mounted body, The said outer peripheral surface concerns on the elastic bush formed so that a clearance gap may arise in an intermediate part in contact with a to-be-attached body in the both ends. That is, the pressure input is reduced by providing a gap to reduce the contact area.
[0011]
And preferably, it is set as the elastic bush which has a stopper by providing a flange part in the end of an outer cylinder, and forming the said flange part toward the outer side so that it may contact | abut with the edge part of a to-be-attached body. Further, the present invention relates to an elastic bush formed so that a gap is formed on the outer peripheral surface of the outer cylinder following the contact portion between the flange portion and the mounted body.
[0012]
Moreover, it is preferable to provide a stopper that restricts axial displacement by providing a flange portion at the other end of the outer cylinder and forming the flange portion inward. Furthermore, in consideration of the case where an elastic protrusion is provided on the flange portion, it is preferable to form the flange portion in a two-step shape.
[0013]
Such an elastic bushing is particularly suitable as an automobile member mount interposed between the suspension member and the vehicle body.
[0014]
The second of the gist of the present invention is a method for manufacturing the elastic bush described above, wherein the gap between the outer peripheral surface of the outer cylinder and the attached body is formed by expanding the diameter by inserting a die. It is related to. Moreover, the clearance gap between the outer peripheral surface of an outer cylinder and a to-be-attached body can also be formed by pressing down by a press process.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The elastic bushing of the present invention includes an outer cylinder, an inner cylinder disposed on the inner peripheral side of the outer cylinder, and an outer cylinder and an inner cylinder fixed between an inner peripheral surface of the outer cylinder and an outer peripheral surface of the inner cylinder. Are elastically coupled to each other. Therefore, when applied to a member mount for automobiles, for example, the displacement input to the vehicle body can be reduced, and at the same time, vibration and noise can be effectively blocked.
[0016]
The elastic bushing is assembled by press-fitting the outer peripheral surface of the outer cylinder into the mounted body. The greatest feature of the elastic bushing according to the present invention is that the outer surface that press-fits the mounted body during press-fitting. It exists in the outer peripheral surface of a cylinder being formed so that a to-be-attached body may be contacted in both ends, and a clearance gap may be produced in an intermediate part. That is, in order to reduce the pressure input, a clearance is provided to reduce the contact area.
[0017]
Here, if it is only necessary to reduce the contact area, for example, as shown in FIG. 5, a gap 6 is formed between the outer tube 1 and the mounted body 4 on one end side by reducing one end of the outer peripheral surface of the outer cylinder 1. It is sufficient to cause the contact and press contact at the other end. However, if there is a gap 6 on one end side, there is a problem that when used in an external environment, rainwater or the like enters the gap 6 to generate rust or the like. Therefore, a clearance should not be originally provided on the contact surface with the mounted body 4.
[0018]
Therefore, in order to meet such conflicting demands, the present invention eliminates a gap so as to come into contact with the mounted body 4 at both ends as shown in FIG. The contact area is reduced so that the gap 6 is generated at the portion, and the pressure input is reduced.
[0019]
Moreover, it is preferable to provide a flange part in the end of an outer cylinder, and to form the said flange part toward the outer side so that it may contact | abut with the edge part of a to-be-attached body. This is because the flange portion is positioned and the press-fitting completion of the mounted body is ensured. It also has a function as a stopper for restricting axial displacement.
[0020]
Further, the position of the gap between the outer peripheral surface of the outer cylinder and the mounted body is not particularly limited, but it is formed so that a gap is generated following the contact portion between the flange portion and the mounted body. It is preferable. If the radius of the bent part of the flange part is large, this will occur because the pressure input increases due to contact with the bent part before the tip of the mounted body contacts the flat part of the flange part. This is to avoid the problem. In this case, one end side of the contact portion between the outer peripheral surface of the outer cylinder and the attached body is a contact portion between the flange portion and the tip of the attached body.
[0021]
It should be noted that the formation of a gap following the contact portion between the flange portion and the mounted body is advantageous in terms of manufacturing, strength, and reliability in addition to the above-described reduction in pressure input. . That is, since it is only necessary to increase the diameter of the end opposite to the flange portion, it is not necessary to make the machining process complicated as in the case of expanding the diameter only at the position away from the flange portion, and the processing is easy. Because it becomes. In addition, when the flange portion also serves as a stopper function for restricting axial displacement, the flange width can be increased, so that a reinforcing effect is obtained. Furthermore, since a large contact area is obtained at the portion opposite to the flange portion, the sealing performance against the intrusion of rainwater or the like can be improved.
[0022]
Moreover, it is preferable to provide another flange part also at the other end of the above outer cylinder so as to be a stopper for restricting displacement in the opposite axial direction. However, this flange portion is formed inward so as not to hinder the press-fitting of the mounted body. Therefore, a stopper function can be added only by bending the end of the outer cylinder without providing a new member.
[0023]
In this case, the flange portion on the other end side is preferably formed in a two-step staircase shape. When the rubber part for buffering is provided on the flange part, if the bent part is one stage, the rubber may be extended to the press-fitting surface of the attached body outside the bent part during vulcanization, and then extended. Since the rubber has to be removed, the rubber does not extend to the press-fitting surface of the attached body in advance in two steps.
[0024]
Such an elastic bush according to the present invention can be used in various places for blocking vibrations and noises, and is particularly suitable as a member mount for automobiles. In other words, the method of assembling the suspension and power train to the frame and connecting the frame to the vehicle body is called the sub-frame method, and the sub-frame is called the suspension member. There is a method through an elastic bush. This elastic bushing is called a member mount, which reduces the displacement input to the vehicle body and at the same time uses the weight of the suspension member to effectively block vibration and noise.
[0025]
The member mount is attached to the suspension member and is usually pressed into a member collar having an opening on the lower side from the bottom to the top, so that the elastic bushing of the present invention which does not require a large pressure input is used. It fits better.
[0026]
Next, although it is the manufacturing method of the elastic bush of this invention, a clearance gap part can be formed by pressing down a part of outer cylinder by diameter expansion by insertion of a die | dye, and a press process. That is, for example, in a member mount, it is necessary to form a gap portion on the outer peripheral surface of the outer cylinder, but a flange portion that bends outward is formed in advance at the lower end of the metal cylinder, and then a die is inserted from above to insert the flange portion. The upper part is expanded in diameter. Therefore, it is possible to form a gap portion that follows the abutting portion between the flange portion and the mounted body very simply by inserting a die. Moreover, it can also form by pressing down the outer peripheral surface of an outer cylinder at a press process.
[0027]
【Example】
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an elastic bush according to the present invention. In FIG. 1, the elastic bushing of the present invention includes a metal outer cylinder 1, a metal inner cylinder 2 disposed substantially in parallel on the inner peripheral side of the outer cylinder 1, an inner peripheral surface of the outer cylinder 1, and an inner It consists of a substantially cylindrical elastic body (rubber) 3 that is vulcanized and bonded to the outer peripheral surface of the cylinder 2 and elastically connects the outer cylinder 1 and the inner cylinder 2.
[0028]
Here, the lower end of the outer cylinder 1 is a flange portion 1A bent outward, and the upper portion of the flange portion 1A is expanded in diameter, and the diameter after the expansion is 70 mm with respect to the original diameter of 66 mm. . Accordingly, a gap 6 is formed following the contact portion 5 between the flange portion 1A and the mounted body 4, and the contact width between the outer cylinder 1 and the mounted body 4 is 6 mm from the original 50 mm. Is reduced to 30 mm. The elastic body (rubber) protrusion 3A extending below the flange portion 1A serves as a buffer material serving as a stopper for axial displacement.
[0029]
Further, the upper end of the outer cylinder 1 is a flange portion 1B bent inward, and serves as a reinforcing metal core for an elastic body (rubber) protrusion 3B extending above the flange portion 1B. The flange portion 1B has a two-step shape, and the elastic body (rubber) projection 3B serving as a buffer stopper for axial displacement extends to the outer peripheral surface of the outer cylinder 1 by the rubber flow during vulcanization. Is to prevent.
[0030]
FIG. 2 is a graph showing the relationship between the press-in depth and the press-in force in the elastic bushing of the present invention shown in FIG. 1 and the conventional elastic bushing shown in FIG. As shown in FIG. 2, in the conventional elastic bush, the pressure input continues to increase until the press-fitting is completed, but in the elastic bush of the present invention, when reaching the gap portion, the pressure input does not increase after that and immediately before the press-fitting is completed. The pressure input is less than half that of the conventional example.
[0031]
FIGS. 3A and 3B are partial cross-sectional views showing a method for manufacturing the outer cylinder 1, FIG. 3A is a method using a die insertion, and FIG. 3B is a method using a pressing process. That is, in the method shown in FIG. 3A, first, the flange portion 1A is formed. The flange portion 1A is formed by pressing a conical die into the lower end portion of the metal cylinder and expanding the diameter, and then pressing the upper portion to form the flange portion 1A that bends outward, as well as providing a hole in the metal plate. There is a method in which a die is inserted into the hole, the periphery of the hole is bent, and this is repeated to form a metal cylinder with the flange portion 1A, but the latter is more advantageous in terms of cost. Next, a die is inserted from above to expand the diameter of the upper portion of the flange portion 1A. Finally, the upper end of the expanded outer cylinder is bent inward by a press to form a two-step stepped flange portion 1B.
[0032]
In the method shown in FIG. 3B, the flange portion 1A is formed in advance at the lower end of the metal cylinder and the flange portion 1B is formed at the upper end in the same manner as in FIG. And the outer peripheral surface of an outer cylinder is pressed down and formed in a press process. That is, first, the metal cylinder with the flange portions 1A and 1B is fixed. Next, a presser mold having an inclined convex portion corresponding to the gap on the inner surface, which can process a part of the circumference of the outer cylinder, not the entire circumference, is repeatedly pressed over the entire circumference and removed. A method for manufacturing a cylinder.
[0033]
【The invention's effect】
According to the elastic bushing of the present invention, the outer peripheral surface of the outer cylinder or the inner peripheral surface of the inner cylinder is formed so that the both ends thereof are in contact with the mounted body and a gap is formed in the intermediate part. While effectively preventing rainwater and the like from entering the contact surface with the body, the contact area with the mounted body can be reduced, and the pressure input can be greatly reduced. Moreover, according to the method for manufacturing an elastic bush of the present invention, an elastic bush having a gap portion in the middle can be manufactured very easily.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an elastic bush according to the present invention.
FIG. 2 is a graph showing the relationship between press-fitting depth and pressure input in the elastic bushing of the present invention and the conventional elastic bushing.
FIG. 3 is a partial cross-sectional view showing a method for manufacturing an outer cylinder in the elastic bushing of the present invention.
FIG. 4 is a cross-sectional view showing a conventional elastic bushing.
FIG. 5 is a cross-sectional view showing an elastic bushing of a comparative example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Outer cylinder 1A ... Flange part 1B ... Flange part 2 ... Inner cylinder 3 ... Elastic body 3A ... Elastic body protrusion 3B ... Elastic body protrusion 4 ... Mounted body 5 ... Contact part 6 ... Gap

Claims (7)

The outer cylinder, the inner cylinder arranged on the inner peripheral side of the outer cylinder, and the elasticity that is fixed between the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder to elastically connect the outer cylinder and the inner cylinder A flange portion that abuts against an end portion of the mounted body at one end of the outer cylinder, and the flange is formed when the outer peripheral surface of the outer cylinder is press-fitted into the mounted body. The outer peripheral surface of the outer cylinder is formed so that the portion abuts against the end of the mounted body, one end side forms a gap with the mounted body, and the other end contacts the mounted body . An elastic bush characterized by that. The flange portion and the end portion of the attached body are in contact with each other in the circumferential direction of the flange portion. The elastic bush according to claim 1, wherein the elastic bush is in contact with each other. The flange part is provided also in the other end of an outer cylinder, The said flange part is formed toward the inner side so that it may become a stopper which controls the displacement of an axial direction, The Claim 1 or 2 characterized by the above-mentioned. Elastic bush. The elastic bush according to claim 3, wherein the flange portion on the other end side is formed in a two-step staircase shape. The elastic bush according to any one of claims 1 to 4, wherein the elastic bush is an automobile member mount interposed between the suspension member and the vehicle body. 6. The method of manufacturing an elastic bush according to claim 1, wherein a gap between the outer peripheral surface of the outer cylinder and the mounted body is formed by expanding the diameter by inserting a die. Production method. 6. The method for producing an elastic bush according to claim 1, wherein a gap between the outer peripheral surface of the outer cylinder and the attached body is formed by pressing in a pressing step.

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