JPH08193640A - Dynamic damper - Google Patents

Abstract

PURPOSE: To prevent the fall of a mass member without impeding the adhesion between an elastic member and the mass member or a fitting plate by providing a holding means fitted with play into a vertically piercing communicating hole so as to fix a fitting member to a vibrating member and to prevent the fall of the mass member at the time of use. CONSTITUTION: A metallic mass member 5 provided with a long cylindrical hole 4 vertically piercing the center part is disposed at the upper part of a plate 3 with a fitting bolt hole 2 bored at the center part. A rubber elastic member 7 with a short cylindrical hole 6 provided at the center part is vulcanization-bonded to connect the plate 3 and the mass member 5 to each other, and the inner peripheral surface of the mass member 5 is covered with an elastic body. A shoulder bolt 9 serving as a holding means, with the head top part provided with a flange part 10 large enough to hold at the detaching time of the mass member 5 is provided in a communicating hole 8 and fitted to a vibrating member. The fall of the mass member 5 can therefore be prevented without the holding means coming in contact to interfere with the mass member and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic damper for reducing vibration from a vibration generating portion by resonance, and more particularly to means for attaching and holding the dynamic damper to a member vibrating by the vibration transmitted from the vibration generating portion.

[0002]

2. Description of the Related Art For example, a member or body panel constituting a vehicle body of a vehicle is equipped with a dynamic damper having a natural frequency equal to the resonance frequency of these members, and the vibration generated by the engine of the vehicle is dynamic. The damper absorbs the vibrations of the vibration members such as the members and the body panel to reduce the vehicle noise.

Conventionally, the dynamic damper 100 is attached to these vibrating members by attaching a plate 106 to the vibrating member 102 in a detachable manner by a mounting bolt 104, as shown in FIGS. 6 (a) and 6 (b). Done by Further, due to harsh environmental conditions such as salt damage and high temperature encountered when using the dynamic damper 100, the rubber 110, which is an elastic body, is vulcanized and bonded to the mass member 108 and the plate 106 and interposed therebetween. Member 108
In order to prevent the risk of the mass member 108 falling off when the mass member 108 is peeled off, the mass member 108 is connected to the plate 106 by a fall prevention pin 112 attached to the mass member 108.

As shown in FIG. 6 (a), the drop-preventing pin 112 has one end loosely fitted in a vertical passage 114 penetrating the mass member 108 in the vertical direction.
Is fixed to the mass member 106 by welding, and the other end projects above the mass member 108 to form a flange 116.
6B, the other end of a captive prevention pin 112, one end of which is welded to the side surface of the mass member 106, is bored at the side end of the plate 106, as shown in FIG. 6B. A structure is used in which a mass member is prevented from falling off by a flange 116 which is loosely fitted in the pin hole 118 and provided at the tip thereof.

[0005]

However, in the drop-prevention pin having such a conventional structure, in order to weld one end of the pin, the rubber as the elastic member and the mass member or the elastic member are heated by the heat at the time of welding. Adhesion with the plate may be adversely affected, and because the pin thickness and the flange provided at one end of the pin are relatively thin and small, the pins will rust during use and their size will be reduced. When peeling occurs, there is a problem in that the mass member may not be fully supported and the fall prevention function may not be fulfilled.

In view of the above circumstances, an object of the present invention is to provide a dynamic damper provided with means for preventing the mass member from falling off without hindering the adhesion between the elastic member and the mass member or the mounting plate. It is to be.

[0007]

To achieve the above object, the dynamic damper of the present invention can vibrate with a mounting member connected to a vibrating vibrating member as claimed in claim 1. A dynamic damper comprising a mass member having a mass sufficient to reduce vibration of a vibrating member, and an elastic member that elastically deformably connects the attachment member and the mass member, wherein a part of the dynamic damper is provided. It is characterized in that it has a communication hole penetrating vertically and has a holding means that is loosely fitted in the communication hole to fix the attachment member to the vibrating member and to prevent the mass member from falling off during use.

[0008]

In the dynamic damper of the present invention, the function of detachably fixing the dynamic damper to the vibrating member and the function of preventing the falling of the mass member can be exhibited by one means. It is not necessary to separately attach a mechanism for preventing the mass member from coming off, such as a damper, and the heat during welding may adversely affect the adhesion between the elastic body and the mass member or the mounting plate. Absent.

Further, in the dynamic damper of the present invention,
Since the mechanism for fixing the dynamic damper to the vibrating member and the mechanism for preventing the mass member from falling off are integrally configured as the holding means, the flange portion that directly supports the mass member when the mass member is separated from the elastic member is used. It is possible to select a large shape and install it in the holding means both in terms of space and strength, and even if the bolt rusts during use, it does not have a great influence on the holding of the mass member. The function of preventing falling is sufficiently ensured.

Further, according to the present invention, since the holding means is structured so as to be loosely fitted and attached to the communication hole penetrating up and down of the dynamic damper, the left and right or front and rear directions of the dynamic damper during use can be improved. The holding means does not interfere with the operation, and thus the original vibration isolation performance of the dynamic damper is not impaired.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described with reference to FIGS. First Embodiment FIG. 1 shows a transverse sectional view of a dynamic damper according to a first embodiment of the present invention. The dynamic damper 1 is provided with a long cylindrical hole 4 having an inner diameter ΦB which is vertically penetrated in the central portion on an upper portion of a plate 3 in which a mounting bolt hole 2 having a small inner diameter ΦA is bored in the central portion. And a rubber elastic member 7 in which a metal mass member 5 is arranged, and similarly, a short cylindrical hole 6 having an inner diameter ΦB is provided in the central portion.
Is vulcanized and adhered so that the plate 3 and the mass member 5 are interposed between them so as to connect them. Then, the bolt hole 2, the long cylindrical hole 4,
A communication hole 8 is formed by concentrically overlapping the short cylindrical hole 6 and integrating them. Further, the elastic body extends from the periphery of the short cylindrical hole 6 of the elastic body 7 to the long cylindrical hole 4 of the mass member 5.
Is extended to the inner peripheral surface of the mass member 5 and the inner peripheral surface of the mass member 5 is covered with an elastic body. Therefore, when the dynamic damper is activated, the mass member 5 is largely displaced, and the mass member 5 should not be displaced.
Even when the stepped bolts 9 described below come into contact with each other, no metal hammering sound is generated.

A stepped bolt 9 as a holding means is provided inside the communicating hole 8 and has a disc-shaped plunge portion 10 having an outer diameter larger than the inner diameter ΦB of the cylindrical hole of the mass member. The dynamic damper 1 is loosely fitted and attached to a vibration member such as a member of the vehicle or a body panel by a screw provided at the tip of the bolt. And
As shown in FIG. 2, in the structure of the stepped bolt 9, a first stem 11 made of a round bar having a diameter smaller than the inner diameter ΦB of the cylindrical hole is provided below the flange portion 10, and further the plate 3 is provided. A second rod-shaped stem 12 having a diameter smaller than the inner diameter ΦA of the bolt hole 2 and having a screw for screwing with the vibration member on the outer peripheral surface is extended from the bottom surface 13 of the first stem 11. It is said that. The thickness of the first stem and the second stem is set to a diameter sufficient to support the dynamic damper 1, and the outer diameter of the flange portion holds the mass member 5 when it is separated from the elastic member during use. Is set to a size large enough for.

The length of the first stem 11 is larger than the total value of the thickness of the mass member 5 and the thickness of the elastic member 7, and the stepped bolt 9 is loosely fitted in the dynamic damper 1. Then, the bottom surface 13 of the first stem 11 abuts the surface of the plate 3 so that a gap is formed between the flange portion 10 and the upper surface of the mass member 5 so that they do not interfere with each other. There is. Further, a hexagonal hole 14 is bored from the upper surface of the flange portion 10 to the inside of the first stem along the axial direction thereof to rotate the stepped bolt 9 when attaching the stepped bolt 9 to a vibrating member. Have been served.

The dynamic damper of the present embodiment is constructed as described above, and has a structure in which the mounting bolt having the function of fixing the dynamic damper is additionally provided with the fall-preventing function, so that it is different from the conventional dynamic damper. It is not necessary to weld the captive pin separately from the mounting bolt. Therefore, it is possible to prevent the trouble that the adhesive effect between the elastic member and the mass member 5 or the mounting plate 3 is reduced by the welding heat. Further, since the outer diameter of the flange portion 10 is much larger than that of the conventional captive pin, even if rust occurs on the stepped bolt during use, the size of the flange portion has a sufficient margin against the corrosion and is sufficient. It can exhibit the fall prevention function. Further, between the communication hole 8 and the stepped bolt 9 provided inside the dynamic damper 1, and the mass member 5.
The gap formed between the surface of the stepped bolt and the flange 10 of the stepped bolt causes the stepped bolt 9 and the mass member 5 or the elastic body 7 to come into contact and interfere with each other when the dynamic damper is used, and the vibration damping effect of the dynamic damper is obtained. Is not disturbed.

Next, a second embodiment will be described with reference to FIG.
The same reference numerals are used for members having the same shapes and functions as those of the first embodiment. In the second embodiment, the mass member 5 is formed by stacking five rectangular plate members 16 each having a large-diameter round hole 15 in the central portion, and thin rubber except for the round hole 15 portion between each of these plate members. 17 is a laminated rectangular parallelepiped 18 bonded by vulcanization. Therefore, an elongated cylindrical hole 19 corresponding to the large-diameter round hole 15 is formed at the center of the laminated rectangular parallelepiped 18.
Moreover, in order to strengthen the integration of these laminated plates, a rectangular thin plate member 22 having a small diameter circular hole 21 in the center is further attached to the lower surface of the lowermost plate member 20 of the laminated rectangular parallelepiped 18. Then, a narrow strip-shaped plate member 23 is extended from the central portions of the left and right front and rear end portions of the thin plate member 22 and passes through the central portion on the side surface of the rectangular parallelepiped 18 to form the uppermost plate 2 of the laminated rectangular parallelepiped 18.
4, the upper and lower surfaces of the laminated rectangular parallelepiped 18 reaching the upper surface of the edge are crimped from the left and right front and rear. And
The entire outer surface of the mass member 5 is thinly covered with rubber to prevent rust. In addition, the mass member 5 and the mounting plate 3
In the thick rubber block 7 as an elastic member that is vulcanized and adhered between the round hole 2 of the rectangular thin plate member 22 and
1 is provided with a short cylindrical hole 25 having the same diameter as that of the mounting plate 3 and is concentrically connected to the bolt hole 2 formed in the center of the mounting plate 3 and the long cylindrical hole 19 of the mass member 5 to communicate with each other. A hole 26 is formed.

In the communication hole 26 of the dynamic damper 1 constructed as described above, the wide T-shaped washer 27 places the flange 28 on the peripheral edge of the round hole 21 of the thin plate member 22 and loosely fits it. Then, the T-shaped washer 27 is inserted and the bolt 29 is loosely fitted in the bolt hole 2 of the mounting plate 3.
The tip of the bolt 29 is screwed with the vibration member so that the dynamic damper 1 can be fixed to the external vibration member.

In the dynamic damper of the second embodiment, in addition to the characteristic of the mass member made of the laminated body that the manufacturing cost is low, the adhesive force of the elastic body which is the characteristic of the present invention described in the first embodiment. Is stable and the fall prevention of the mass member is effectively guaranteed.

Although the stepped bolt is used as the holding means of the present invention in the first embodiment, the shape of the holding means is not limited to this from the point of the present invention.
As illustrated in (a), a T-shaped washer having a wide flange may be fitted on an ordinary bolt. Further, as shown in FIG. 4B, the flange of the stepped bolt and the flange of the washer are not circular but hexagonal or quadrangular, and various types can be selected in consideration of ease of tightening the bolt.

Further, as the mass member, in addition to the mass member described in the above-mentioned embodiment, a unitary structure in which cast iron blocks and pipe materials are sliced, or a plurality of press-punched plates are directly laminated to form a laminated body. In order to integrate these, it is possible to use a structure in which the side surfaces of the laminate are welded vertically.

Further, it is possible to give directionality by changing the resonance frequency of the dynamic damper between the front and rear and the left and right as a rectangular parallelepiped having a rectangular cross section, without making the shape of the mass member cylindrical without directivity in the vibration direction. That is, when the width of the mass member in the left-right direction is wider than the width in the front-rear direction, the resonance frequency in the left-right direction is set high, while the resonance frequency in the front-rear direction is set low.

Further, as described above, when the mass member is directional, a pin-shaped projection (see FIG. 5) is provided on the mounting plate.
(A)), or by providing a positioning means such as attaching an L-shaped bend to the edge of the mounting plate (FIG. 5 (b)), the direction of the dynamic damper can be definitely determined at the time of mounting. .

[0022]

As described above, in the dynamic damper of the present invention, the holding means has a structure having both the function of fixing the mounting plate of the dynamic damper to the vibrating member and the function of preventing the mass member from falling off. Therefore, it is not necessary to attach the drop-out prevention pin by welding, and the welding heat does not hinder the vulcanization adhesion of the elastic member (rubber) that connects the mass member and the mounting plate. In addition, since the shape of each member constituting the holding means, particularly the shape of the mass member supporting flange, is set to be large, the mass member separated from the elastic member (rubber) should be removed even if it is corroded by rust during use. It can be held securely. Further, since the holding means is structured so as to be loosely fitted and attached to the communication hole penetrating up and down of the dynamic damper, the holding means does not contact and interfere with the mass member or the elastic member, and the dynamic damper is originally designed. The anti-vibration property is not deteriorated.

Therefore, according to the present invention, it is possible to provide a dynamic damper capable of effectively preventing the mass member from falling off without inhibiting the vulcanization adhesion of the elastic member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a dynamic damper according to a first exemplary embodiment.

FIG. 2 is an exploded view of the first embodiment.

FIG. 3 is a cross-sectional view of a dynamic damper according to a second exemplary embodiment.

4 (a) and 4 (b) are views showing various shapes of holding means.

5 (a) and 5 (b) are views showing the positioning means of the dynamic damper.

FIG. 6 is a horizontal cross-sectional view of a conventional dynamic damper (a), which is a diagram showing an example of a dropout prevention pin. It is a figure which shows the other example of (b) and a fall prevention pin.

[Explanation of symbols]

 1 Dynamic Damper 2 Bolt Hole 3 Plate 4 Long Cylindrical Hole 5 Mass Member 6 Short Cylindrical Hole 7 Elastic Member 8 Communication Hole 9 Stepped Bolt 10 Flange Part 11 First Stem 12 Second Stem 13 Bottom 14 Hexagonal Hole 15 Large diameter round hole 16 Rectangular plate material 17 Thin rubber 18 Laminated rectangular parallelepiped 19 Long cylindrical hole 20 Bottom layer plate material 21 Small diameter round hole 22 Rectangular thin plate material 23 Strip plate material 24 Top layer plate material 25 Short cylindrical hole 26 Communication Hole 27 Collar wide T-type washer 28 Collar 29 Bolt 100 Dynamic damper 102 Vibration member 104 Mounting bolt 106 Plate 108 Mass member 110 (Elastic member) Rubber 112 Fall prevention pin 114 Sitway 116 Flange portion 118 Pin hole

Claims (1)

[Claims] 1. A mounting member connected to a vibrating vibrating member, a mass member having a mass sufficient to reduce vibration of the vibrating vibrating member, and the mounting member and the mass member can be elastically deformed. A dynamic damper comprising an elastic member coupled to the above, wherein a part of the dynamic damper has a communication hole vertically penetrating, and the mounting member is fixed to the vibrating member by being loosely fitted in the communication hole. A dynamic damper characterized by having holding means for preventing the mass member from falling off during use.