JP2021032382A - Vehicular bushing - Google Patents

Abstract

To provide a vehicular bushing that can provide excellent vibration damping performance in a wide vibration frequency region.SOLUTION: A vehicular bushing 1A includes: an outer cylindrical member 10A; an inner cylindrical member 20A provided radially inward of the outer cylindrical member 10A; a rubber member 30 provided between the outer cylindrical member 10A and the inner cylindrical member 20A; and a spring member 40 provided inside the rubber member 30. The spring member 40 has a hollow shape.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle bush.

Patent Document 1 describes a vehicle bush that improves vibration damping performance by providing a rubber member and a metal spring member in series.

Japanese Unexamined Patent Publication No. 2018-021627

In such a vehicle bush, the spring member aims to improve the vibration absorption performance of the vehicle bush by relaxing the frequency dependence of the spring constant of the rubber member. That is, in the conventional bush for vehicles, the spring member does not widen the frequency range in which the rubber member can realize the vibration damping performance.

The present invention has been devised in view of the above matters, and an object of the present invention is to provide a bush for a vehicle capable of realizing high vibration damping performance in a wide frequency range.

In order to solve the above-mentioned problems, the vehicle bush of the present invention has a cylindrical outer member, a cylindrical or cylindrical inner member provided radially inward of the outer member, and the outer member. A rubber member provided so as to connect between the inner members and a spring member provided in the rubber member, and the spring member has a hollow shape.

According to the present invention, the spring constant frequency dependence of the hollow spring member is smaller than the frequency dependence of the spring constant of the rubber member as the base material, and the spring member is arranged in series with the rubber member. By doing so, the increase in the spring constant is suppressed, so that high vibration damping performance can be realized in a wide frequency range.

It is a perspective view which shows the bush for a vehicle which concerns on 1st Embodiment of this invention. It is a figure which looked at the bush for a vehicle which concerns on 1st Embodiment of this invention from the axial direction. It is a graph for demonstrating the relationship between the load and displacement in a vehicle bush. It is a graph for demonstrating the frequency dependence of a spring constant. It is a graph for demonstrating the frequency dependence of an amplitude magnification. It is sectional drawing which shows the bush for a vehicle which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the bush for a vehicle which concerns on 3rd Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as appropriate. The same components are designated by the same reference numerals, and duplicate description will be omitted.

<First Embodiment>
As shown in FIGS. 1 and 2, the vehicle bush 1A according to the first embodiment of the present invention is a vibration absorbing member for suppressing transmission of road surface vibration, engine vibration, and the like to the vehicle body. The vehicle bush 1A includes an outer cylindrical member 10A, an inner cylindrical member 20A, a rubber member 30, and a pair of spring members 40 and 40.

<Outer cylindrical member>
The outer cylindrical member (also referred to as an outer pipe) 10A is a highly rigid tubular member formed of a metal such as iron or an aluminum alloy. The outer cylindrical member 10A is connected to one member of the vehicle (for example, a suspension arm or the like).

<Inner cylindrical member>
The inner cylindrical member (also referred to as an inner collar) 20A is a highly rigid tubular member formed of a metal such as iron or an aluminum alloy. The inner cylindrical member 20A is connected to a member different from the member to which the outer cylindrical member 10A is connected. The outer diameter of the inner cylindrical member 20A is smaller than the inner diameter of the outer cylindrical member 10A. The axial dimension of the inner cylindrical member 20A is larger than the axial dimension of the outer cylindrical member 10A. The inner cylindrical member 20A is housed in the outer cylindrical member 10A so as to be coaxial with the outer cylindrical member 10A and so that both ends in the axial direction of the inner cylindrical member 20A protrude from the outer cylindrical member 10A.

<Rubber member>
When an external force is input to one of the outer cylindrical member 10A and the inner cylindrical member 20A, the rubber member 30 attenuates the external force by generating a reaction force based on the spring constant of the rubber member 30. It is transmitted to the other of the outer cylindrical member 10A and the inner cylindrical member 20A. The rubber member 30 has a cylindrical shape. The inner diameter of the rubber member 30 is equal to the outer diameter of the inner cylindrical member 20A, and the outer diameter of the rubber member 30 is equal to the inner diameter of the outer cylindrical member 10A. The axial dimension of the rubber member 30 is equal to or slightly smaller than the axial dimension of the outer cylindrical member 10A. The rubber member 30 is housed between the outer cylindrical member 10A and the inner cylindrical member 20A. The inner peripheral surface of the rubber member 30 is fixed to the outer peripheral surface of the inner cylindrical member 20A by vulcanization adhesion or the like, and the outer peripheral surface of the rubber member 30 is fixed to the inner peripheral surface of the outer cylindrical member 10A by vulcanization adhesion or the like. Has been done. The rubber member 30 is miniaturized in the axial direction (radial direction) by inserting the spring member 40, and the spring constant in the axial direction and the circumferential direction (rotational direction) is not changed. The spring constant (in the radial direction) is increased.

<Spring member>
The spring member 40 is a plate-shaped member that adjusts the spring constant of the rubber member 30 by being provided in the rubber member 30. The spring member 40 may be made of metal, resin, or rubber having a smaller frequency dependence of the spring constant than the rubber member 30 of the base material. Here, since the metal spring member 40 is composed of three-dimensional metal bonds, it is less affected by inertial force and has almost no frequency dependence as compared with those made of resin or rubber. .. The spring member 40 is elastically deformable in the axial direction, that is, in the radial direction. The axial dimension of the spring member 40 is larger than the axial dimension of the rubber member 30. The spring member 40 has a hollow shape, more specifically, a closed cross-sectional shape in an axial view, and in the present embodiment, the spring member 40 includes an outer spring portion 41 and an inner spring portion 42. The outer spring portion 41 and the inner spring portion 42 have an arc shape having a diameter larger than that of the outer peripheral surface of the inner cylindrical member 20A and a diameter smaller than that of the inner peripheral surface of the outer cylindrical member 10A. The inner spring portion 42 has a diameter slightly smaller than that of the outer spring portion 41, and is provided inward in the radial direction of the outer spring portion 41. The outer spring portion 41 and the inner spring portion 42 (for example, both made of metal) are connected to each other by welding (for example, electron beam welding) at both ends in the circumferential direction.

In this embodiment, two spring members 40 having an arc shape slightly smaller than a semicircle are arranged in the circumferential direction. The spring member 40 may have a structure in which the rubber member 30 is filled in the hollow portion of the spring member 40. Further, in the spring member 40, the openings at both ends of the hollow portion of the spring member 40 in the axial direction are closed by the seal portion 43 (see FIGS. 5 and 6) described later, and the rubber member 30 is contained in the hollow portion. The configuration may not be provided.

The structure in which the spring member 40 is provided in the rubber member 30 can be formed by, for example, insert molding.

Such a vehicle bush 1A can be applied to, for example, a vehicle suspension. In this case, the outer cylindrical member 10A is connected to the vehicle body, and the inner cylindrical member 20A is connected to the yoke portion of the suspension arm via bolts.

<Spring constant>
A vehicle bush 1A according to the first embodiment of the present invention and a conventional vehicle bush provided with a spring member made of a single plate have been prototyped as a comparative example. Here, the static spring constant synthesized by the rubber member 30 and the spring member 40 of the vehicle bush 1A according to the first embodiment of the present invention is a comparative example within a load in which the spring function of the spring member 40 effectively acts. It is set to be equal to the static spring constant of the spring member made of one plate and the rubber member. As shown in FIG. 3, the hollow portion between the outer spring member 41 and the inner spring member 42 is maintained in the region where the load is small (0 or more and _{less than the first value N 1), and the spring member 40 has the spring member 40.} It functions effectively as a spring. In such a region, the static spring constant of the vehicle bush 1A is equal to the static spring constant of the vehicle bush of the comparative example. Further, in the region where the load is medium (first value N ₁ or more, second value N _{2 or} less), the hollow portions of the outer spring member 41 and the inner spring member 42 are crushed, and the spring member 40 is a spring. Does not work as. In such a region, the static spring constant of the vehicle bush 1A is larger than the static spring constant of the vehicle bush of the comparative example. Further, in the region where the load is large (second value N ₂ or more), the spring member 40 does not function as a spring, and the rubber member 30 shows remarkable non-linearity. In such a region, the static spring constant of the vehicle bush 1A is larger than the static spring constant of the vehicle bush of the comparative example. The performance of these vehicle bushes was evaluated using a vibration exciter.

The measurement result of the spring constant is shown in FIG. It is generally known that the spring constant of the rubber member 30 increases as the frequency increases. In the structure of the rubber member and the single-plate spring member of the comparative example, the spring constant increases as the frequency increases, whereas in the vehicle bush 1A according to the first embodiment of the present invention, the spring constant increases. The increase in the spring constant with the increase in frequency is suppressed. This is because the frequency dependence of the spring constant in the hollow spring member 40 is smaller than the frequency dependence of the spring constant in the rubber member 30 which is the base material, and the spring member 40 is in series with the rubber member 30. This is because it is located in.

The amplitude magnification calculated from the spring constant is shown in FIG. It can be seen that in the vehicle bush 1A according to the first embodiment of the present invention, the amplitude magnification is suppressed to be small in the high vibration region as compared with the comparative example, and high vibration damping performance is realized. Such an effect of the vehicle bush 1A is particularly preferably obtained when the spring member 40 is made of metal.

That is, in the vehicle bush 1A, the spring member 40 has a function of increasing the spring constant in the axial direction of the rubber member 30, and the spring member 40 itself vibrates to absorb the vibration input to the rubber member 30. Has the function of Further, in the vehicle bush 1A, the rubber member 30 mainly absorbs the vibration at the time of low frequency or large displacement input, and the spring member 40 having a small phase delay with respect to the vibration mainly absorbs the vibration at the high frequency. Therefore, the vehicle bush 1A can realize high vibration damping performance in a wide frequency range. The vehicle bush 1A can improve the vibration damping performance while maintaining the synthetic spring constant constant by increasing the spring constant of the rubber member 30 and decreasing the spring constant of the spring member 40.

The vehicle bush 1A according to the first embodiment of the present invention has a cylindrical outer member (outer cylindrical member 10A) and a cylindrical or cylindrical outer member, which is provided inward in the radial direction of the outer member. The spring member 40 includes a member (inner cylindrical member 20A), a rubber member 30 provided so as to connect the outer member and the inner member, and a spring member 40 provided in the rubber member 30. , It is characterized by exhibiting a hollow shape.
Therefore, in the vehicle bush 1A, the frequency dependence of the spring constant in the spring member 40 having a hollow shape is smaller than the frequency dependence of the spring constant in the rubber member 30 which is the base material, and the spring member 40 is the rubber member. By arranging in series with respect to 30, the increase in the spring constant is suppressed, so that high vibration damping performance can be realized in a wide frequency range.

Further, the vehicle bush 1A includes an outer spring portion 41 in which the spring member 40 exhibits an arc shape and an inner spring portion 42 provided in the radial direction of the outer spring portion 41, and the outer spring portion The 41 and the inner spring portion 42 are connected to each other at both ends in the circumferential direction.
Therefore, the vehicle bush 1A can realize the hollow spring member 40 with a simple structure.

Further, the vehicle bush 1A is characterized in that the spring member 40 is made of metal.
Here, the metal spring member 40 is less affected by the inertial force of the spring member 40 and has almost no frequency dependence. Therefore, in the vehicle bush 1A, the rubber member 30 mainly absorbs the vibration at the time of inputting a low frequency or a large displacement, and the metal spring member 40 having a small transfer delay with respect to the vibration mainly absorbs the vibration at a high frequency. That is, the vehicle bush 1A can more preferably realize high vibration damping performance in a wide frequency range.

<Second embodiment>
Subsequently, the vehicle bush according to the second embodiment of the present invention will be described focusing on the differences from the vehicle bush 1A according to the first embodiment. As shown in FIG. 6, the vehicle bush 1B according to the second embodiment of the present invention includes an outer cylindrical member 10B instead of the outer cylindrical member 10A.

The outer cylindrical member 10B is a so-called different diameter pipe, and extends from the small diameter portion 11 forming one end in the axial direction of the outer cylindrical member 10B and the other end in the radial direction of the small diameter portion 11, and is an axial end. A diameter-expanded portion 12 whose diameter increases toward the other end, and a large-diameter portion 13 which extends from the axially opposite end side of the diameter-expanded portion 12 and constitutes the axially opposite end of the outer cylindrical member 10B. And, in one piece. The outer peripheral surface of the rubber portion 30 is fixed over the small diameter portion 11 and the large diameter portion 13 across the enlarged diameter portion 12 of the inner peripheral surface of the outer cylindrical member 10B. The gaps formed at both ends of the outer spring portion 41 and the inner spring portion 42 in the axial direction are closed by the seal portion 43 that does not hinder the elastic deformation of the outer spring portion 41 and the inner spring portion 42. The seal portion 43 is formed by welding both ends in the axial direction of the outer spring portion 41 and the inner spring portion 42 (for example, both made of metal) so as to withstand an axial load and a rotational torque. Has been done.

<Third embodiment>
Subsequently, the vehicle bush according to the third embodiment of the present invention will be described focusing on the differences from the vehicle bush 1A according to the first embodiment. As shown in FIG. 7, the vehicle bush 1C according to the third embodiment of the present invention includes an inner cylindrical member 20C instead of the inner cylindrical member 20A.

The inner cylindrical member 20C is a so-called different-diameter pipe, which extends from a large-diameter portion 21 constituting an axial intermediate portion and both ends in the axial direction of the large-diameter portion, and has a reduced diameter toward the axial end. The reduced diameter portions 22 and 22 and the small diameter portions 23 and 23 extending from the axial end portions of the reduced diameter portions 22 and 22 and forming the axial end portion of the inner cylindrical member 20B are integrally provided. .. A flange portion 24 extending outward in the radial direction is formed at the axial end portion of the small diameter portion 23. The inner peripheral surface of the rubber portion 30 is fixed over the small diameter portions 23, 23 across the large diameter portion 21 and the reduced diameter portions 22, 22 of the outer peripheral surface of the inner cylindrical member 20C.

In the vehicle bush described in Patent Document 1, the spring member made of a single metal plate is provided along the inner peripheral surface of the outer cylindrical member or the outer peripheral surface of the inner cylindrical member, and the spring member and the said spring member. No rubber member is provided between the spring member and the peripheral surface along which the spring member runs. On the other hand, as shown in the second embodiment and the third embodiment, in the vehicle bush of the present invention, a spring member is provided in the rubber member (what are the outer cylindrical member and the inner cylindrical member? Since they are separated and a rubber member is provided between the spring member and both the outer cylindrical member and the inner cylindrical member), even when at least one of the outer cylindrical member and the inner cylindrical member is a pipe having a different diameter. It is suitably applicable.

In the vehicle bush 1B according to the second embodiment of the present invention, at least one of the inner peripheral surface of the outer member and the outer peripheral surface of the inner member (here, the outer cylindrical member) at the portion where the rubber member 30 is attached. The inner peripheral surface of 10B) is characterized in that its diameter changes in the axial direction.
Therefore, in the vehicle bush 1B, since the spring member 40 is separated from the inner peripheral surface of the outer cylindrical member 10B and the outer peripheral surface of the inner cylindrical member 20A, wide vibration occurs even when the outer cylindrical member 10B is a pipe having a different diameter. High vibration damping performance can be achieved in several areas.

Further, in the vehicle bush 1C according to the third embodiment of the present invention, at least one of the inner peripheral surface of the outer member and the outer peripheral surface of the inner member (here, the inner side) at the portion where the rubber member 30 is attached. The inner peripheral surface of the cylindrical member 20C) is characterized in that its diameter changes in the axial direction.
Therefore, in the vehicle bush 1C, since the spring member 40 is separated from the inner peripheral surface of the outer cylindrical member 10A and the outer peripheral surface of the inner cylindrical member 20C, wide vibration occurs even when the inner cylindrical member 10C is a pipe having a different diameter. High vibration damping performance can be achieved in several areas.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be appropriately modified without departing from the gist of the present invention. For example, in the rubber member 30, two or more spring members 40 may be provided side by side in the radial direction. Further, the spring member made of a single plate may be provided in the vicinity of the inner peripheral surface of the outer cylindrical members 10A and 10B and / or in the vicinity of the outer peripheral surface of the inner cylindrical members 20A and 20C. Further, the inner cylindrical members 20A and 20C may be inner cylindrical members having a cylindrical shape. Further, the vehicle bush of the present invention can be applied to a portion connecting each part of the vehicle and the vehicle body such as a suspension arm and a damper.

1A, 1B Vehicle bush 10A, 10B Outer cylindrical member (outer member)
20A, 20C Inner cylindrical member (inner member)
30 Rubber member 40 Spring member 41 Outer spring part 42 Inner spring part

Claims (4)

An outer member that has a cylindrical shape and
An inner member having a cylindrical shape or a cylindrical shape and provided inward in the radial direction of the outer member,
A rubber member provided so as to connect the outer member and the inner member,
A spring member provided in the rubber member and
With
The spring member is a vehicle bush characterized by having a hollow shape. The spring member is
The outer spring part that has an arc shape and
An inner spring portion provided inward in the radial direction of the outer spring portion, and an inner spring portion.
With
The vehicle bush according to claim 1, wherein the outer spring portion and the inner spring portion are connected to each other at both ends in the circumferential direction. The first or second aspect of the present invention, wherein at least one of the inner peripheral surface of the outer member and the outer peripheral surface of the inner member changes in diameter in the axial direction at a portion to which the rubber member is attached. Vehicle bush. The vehicle bush according to any one of claims 1 to 3, wherein the spring member is made of metal.

Images