GB2165918A - Vibration-damping device - Google Patents

Abstract

A vibration-damping device comprises at least one columnar member 1, one end of which is fixable to a vehicle body or component, a tubular member 2 for fitting to each columnar member 1, a weight member 3 disposed adjacent to the tubular member 2, and a rubber elastomeric member 4 interposed between the weight member and the tubular member to unite them. The device is supplied in two parts, the columnar member 1 and a unit comprising the tubular member 2 elastomer 4 and weight 3. The columnar member 1 is attached to the vehicle body, and the unit is then affixed to the columnar member 1 by means of the tubular member 2. Columnar member 1 may be a force fit in tubular member 2 or may be arranged to extend through the tubular member 2 and be flanged over at its end to attach the unit to the vehicle body. As shown, a plurality of columnar members 1 and tubular members 2 may be used. <IMAGE>

Description

SPECIFICATION Vibrating-damping device This invention relates to a vibration-damping device capable of absorbing oscillations transmitted to a vehicle body to exhibit vibration-damping performance.

A wide variety of devices are known for absorbing oscillations, which devices use a combination of the elasticity of rubber and the resistance to oscillation of a heavy member.

Three typical devices of this type will be exemplified below.

In one example, a device is formed, as shown in Fig. 5, so that a base plate body 5 and a weight member 3 are connected by a rubber elastomeric member 4 and the plate body 5 is fixed to a vehicle body or to a vehicle component secured to the vehicle body by nut and bolt connections N,B.

Another device is illustrated in Fig. 6 and formed so that a weight member 3 is united and connected to a vehicle component 6 such as an engine mounting bracket by vulcanization bonding treatment of a rubber elastomeric body 4.

A further device is, as shown in Fig. 7, constructed so that a cylindrical member 1' and a weight member 3 are connected by a rubber elastomeric body 4 and the cylindrical member 1' is bolted to a vehicle body.

The first and third devices stated above use screw type fixing and, consequently, give resuit in decreased productivity due to an increase in the number of operations performed during assembly and an increase in assembling time. On the other hand, the second aforesaid device has a defect in that where the vehicle component is large, the cavity number of the vulcanizing mold for rubber is decreased or the vulcanization mold for rubber is required to be large in size, which results in an increase in cost and a lowering of productivity. It is also disadvantageous in that the use of the device is limited, being applicable only to vehicle components having a face which can be bonded to the device by vulcanization.

Thus, conventional vibration-damping devices required troublesome attachment operations and have productivity difficulties in them, which further leads to a rise in the cost of the devices.

The present invention aims to deal with the foregoing prior art problems or difficulties.

An aim of the present invention is to provide a vibration-damping device which requires a smail area of attachment to a vehicle body or a vehicle component and in which only a columnar memberthat is readily attachable participates in the attaching operation and installation of the device can be conducted by a simple means such as press fitting or caulking, thereby to obviate the limitations inherent on attachment and enhance productivity.

Accordingly, the present invention provides a vibration-damping device comprising one or more columnar members arranged axially in parallel, one end of each being fixed to a vehicle body or a vehicle component secured to the vehicle body in a projecting manner; one or more cylindrical members each of which is arranged to correspond to each of a respective columnar member in orientation and is adapted to be fitted and firmly secured to the columnar member; a weight member disposed adjacent the cylindrical member(s); and a rubber elastomeric body interposed between the or each columnar member and the weight member to connect them.

According to a preferred embodiment of this invention, the columnar member has a maximum outer radius greater than the minimum inner radius of the cylindrical member and is press fitted into the cylindrical member with a light force, and the head portion of the columnar member is, after fitting, compressed and radially expanded, thus securing the columnar member to the cylindrical member.

According to this invention, only the columnar member is fixed to a vehicle body or a vehicle component, and the integral unit comprising the cylindrical member, weight member and rubber elastomeric body is press fitted onto the columnar member or secured to the columnar member by caulking or other means, whereby a vibrationdamping device is assembled and set up.

Hence the assembly work is very simple and easy; a space corresponding to the attachment area of the columnar member to a vehicle body or a vehicle component is sufficient for the attachment area of the device to the vehicle body or vehicle component; there are substantially no limitations in attaching the device; and the device can be installed in an optimum position for the absorption of vibration.

The invention will be further described by way of example with reference to the accompanying drawings in which: Fig. 1 is a schematic plan view of an embodiment of the invention; Fig. 2 is a sectional view of the embodiment in Fig. 1 when disconnected; Fig. 3 is a partial sectional view of another embodiment of the invention; Fig. 4 is a perspective view of a further embodiment of the invention when disconnected; and Fig. 5 to Fig. 7 are schematic illustrations of prior art vibration-damping devices.

In each embodiment shown in Fig. 1 to Fig.

3, the vibration-damping device comprises a columnar member 1, a cylindrical member 2, a weight member and a rubber elastomeric body 4 as primary elements.

The cylindrical member 2, the weight member 3 and the rubber elastomeric body 4 are bonded together to form an integral unit, whereas the columnar member 1 constitutes in itself a single counterpart unit. The two units are connected together to complete the vibration-damping device.

The columnar member 1 is made of a rigid material such as metal and comprises a column portion having a suitable radius with a pedestal having a somewhat larger cross-sectional area than the column portion formed integrally with the column portion.

The pedestal has a mounting surface designed conforming to the surface of a vehicle body or a vehicle component on which the pedestal is to be mounted, and is fixed to the vehicle body etc. in its predetermined position by bolting, screwing, welding or the like so that it projects upright from the vehicle body.

The cylindrical member 2 is shaped in the form of a cylinder having a hollow portion with an inner radius such that it can be secured to the columnar member 1 so that there is no play when fitted onto the columnar member. It is also made of a rigid material such as metal.

The weight member 3 is in the form of a heavy weight block made of rigid material having a large specific gravity such as cast iron.

The weight member 3 having a required shape is disposed adjacent to the cylindrical member 2 to surround it or the cylindrical member may be located alongside of the weight member 3.

Between the weight member 3 and the cylindrical member 2 is interposed the rubber elastomeric body 4. It is bonded firmly to both members 2,3 thereby to connect the cylindrical member 2 and the weight member 3 through the rubber elastomeric body 4.

The connection with the rubber elastomeric body 4 can be conducted simply and assuredly by interposing a material of natural rubber or synthetic rubber between both members 2,3 each disposed in a predetermined position and subjecting it to vulcanization bonding treatment under heating.

In Figs. 1 and 2, there is shown an example in which the weight member 3 is columnar or prismatic and apertured at its center with a through-hole having a radius larger than that of the cylindrical member 2, and the cylindrical member 2 is inserted concentrically in the through-hole with a play and in that state, the rubber elastomeric body 4 is introduced into the space around the cylindrical member 2 to perform vulcanization bonding.

The integrated unit of the cylindrical member 2 and the weight member 3 thus united is secured to the columnar member 1 which is fixed to a vehicle body in its predetermined position in a projecting manner by inserting and fitting the columnar member 1 into the cylindrical member 2. In this way, the vibration-damping device is installed on the vehicle body.

In securing the columnar member 1 to the cylindrical member 2, a forced press fitting means or a caulking means after light press fitting is adopted and allows firm fastening.

In the case of a forced press fitting means, it is preferred that the axial lengths of the columnar member 1 and the cylindrical member 2 be substantially equal and the columnar member 1 be formed to have a maximum outer radius greater than the minimum inner radius of the cylindrical member 2.

On the other hand, upon securing by a caulking means, it is preferred that the cylindrical member 2 have a slightly shorter axial length than the columnar member 1 and have a miminum inner radius portion formed so that it can be fitted onto the columnar member 1 with a light force. After fitting into the cylindrical member 2, the projecting head of the columnar member 1 is flanged, compressed and expanded in its radius, to secure it to the cylindrical member, as shown in Fig. 3.

The embodiment thus far described is concerned with a device comprising the single columnar member 1 as the one unit and one piece of the single cylindrical member 2 as the other unit.

Another embodiment is of a construction as illustrated in Fig. 4 in which a plurality (for example 3) of columnar members 1 and an equal number of cylindrical members 2 are provided. Here, it is a requisite that two or more columnar members 1 be fixed in a projecting manner so as to be substantially parallel with one another in the axial direction, and the cylindrical members 2 are arranged with the same orientation as the columnar members.

The weight member 3 is disposed inwardly of the cylindrical members 2 so as to be surrounded by them as shown in Fig.4. Otherwise, the weight member 3 may be formed with one or more through-holes corresponding to respective columnar members 1, and the respective cylindrical members 2 are concentrically fitted in the through-holes and subsequently united with the weight member by a rubber elastomeric body 4.

The aforesaid embodiment in which a plurality of the columnar members 1 and a plurality of the cylindrical members 2 are provided is intended for a case where a vehicle body has a wide attachment surface, and permits stabile fixing to the vehicle body.

The vibration-damping device thus constructed and fixed to the vehicle body absorbs maximum amplitude oscillations against oscillations transmitted from the vehicle body to alleviate the oscillations, as is the case with prior art devices of this type.

As will be apparent from the foregoing description, with the vibration-damping device of this invention, assembling work can be conducted readily, simply and quickly since after the columnar member 1 is preliminarily attached to a vehicle body or a vehicle component, assembling can be done by only one operation of forced press fitting or caulking.

A fabricating process of the device according to this invention is substantially finished with a process of uniting the cylindrical member 2 and the weight member 3 with the rubber elastomeric body 4 by vulcanization bonding. As a consequence, mass production can be performed rationally and mass production efficiency is enhanced as compared with prior art assembling processes in which a weight member is secured to a large-size vehicle component by direct vulcanization because vulcanization unit is decreased.

Further, where a mounting face to which the vibration damping device will be attached has few flat portions or is small in space and thread fastening or direct vulcanization is difficult, the device can be installed if only there is a space admitting of attachment of a single columnar member. Hence an optimum place for absorption of oscillations can be optionally selected, and a wide spectrum of applications are possible.

Claims (6)

1. A vibration-damping device comprising a columnar member one end of which is attachable to a vehicle body or a vehicle component secured to a vehicle body to project therefrom; a tubular member for receiving therewithin said columnar member so as to be secured firmly to it; a weight member disposed adjacent to said tubular member; and a rubber elastomeric body interposed between said weight member and said tubular member and connecting them together, whereby said tubular member, said weight member and said rubber elastomeric body constitute an integrated unit and said columnar member constitutes a counterpart single unit which can be fitted in and secured to the tubular member of the integrated unit after attachment to a vehicle body or component thereby to assemble said device.

2. A vibration-damping device as claimed in claim 1, wherein said columnar member and tubular member are cylindrical and said columnar member has a maximum outer radius larger than the minimum inner radius of said cylindrical member, and said columnar member and said cylindrical member are securable firmly to each other by forced press fitting of the former into the latter.

3. A vibration-damping device as claimed in claim 1, wherein said tubular member has a slightly shorter axial length than the columnar member, and in use said columnar member is fitted in said tubular member and then the head portion of it is flanged to secure the columnar member firmly to the tubular member.

4. A vibration-damping device as claimed in claim 1, 2 or 3, comprising a plurality of columnar members and an equal number of cylindrical members.

5. A vibration-damping device as claimed in claim 4, wherein the cylindrical members are substantially parallel and, in use, the columnar members are affixed to said vehicle body or the like to be substantially parallel and each arranged to cooperate with a respective cylindrical member.

6. A vibration-damping device substantially as hereinbefore described with reference to Fig. 1, Fig. 2, Fig. 3 or Fig. 4 of the accompanying drawings.