JP5962199B2 - Anti-vibration structure - Google Patents

Description

  The present invention relates to an anti-vibration structure, and more particularly, to an anti-vibration structure that can reduce vibrations generated in engine components without increasing cost and weight as compared with the prior art.

  Engine components such as cylinder blocks and head covers generate vibrations when the engine is running or the vehicle is running. If such vibrations become excessive or continue for a long time, they will only affect the engine drive. In the worst case, the engine may be damaged. Conventionally, as a countermeasure, a structural member of an engine is formed using a damping steel plate (see, for example, Patent Document 1).

  This damping steel plate has a structure in which a plurality of metal plates and plastic plates are laminated, and the vibration energy is converted into thermal energy by absorbing the displacement between the plates caused by the deformation due to vibration by the friction between the plates. It has a function to reduce vibration by converting.

  However, since the damping steel plate is generally expensive and heavy, there is a problem that the material cost and manufacturing cost of the engine are increased and the engine weight is increased. Therefore, it is desired to develop an anti-vibration structure that can reduce vibration without increasing the cost and weight.

JP 2005-255071 A

  An object of the present invention is to provide a vibration isolating structure that can reduce vibration applied to a member without increasing cost and weight as compared with the conventional art.

The vibration-proof structure of the present invention that achieves the above object is a vibration-proof structure that reduces vibration applied to a member, and includes a through-hole formed in the member, a bolt that can be inserted into the through-hole, and the bolt The boss is loosely fitted, the boss is loosely fitted to the bolt inserted into the through hole , and a rotation stop of the bolt is provided .

The above rotation stop is bent a part of the sandwiched plate member between said member and the bolt head, constituted by making contact with the sides of the head of the bolt. By comprising in that way, while being able to stop rotation of a volt | bolt easily, it can prevent that the cost and weight of a vibration isolating structure increase excessively.

  The present invention can be suitably used for engine components.

  According to the vibration isolating structure of the present invention, since the vibration energy applied to the member is converted into heat energy by the bolt moving with respect to the boss, the vibration of the member can be reduced. Further, since only the bolts and bosses need be attached to the member, the material cost, the manufacturing cost, and the weight are not increased as compared with the conventional case.

It is an assembly drawing of the vibration isolating structure which consists of embodiment of this invention. It is a block diagram of the vibration proof structure which consists of embodiment of this invention. It is a perspective view which shows the example of the rotation stop of a volt | bolt. It is a graph which shows the measurement result of an Example. It is a graph which shows the measurement result of the magnitude | size of the vibration in Example 1 of Table 1. FIG. It is a graph which shows the measurement result of the magnitude | size of the vibration in the comparative example 1 of Table 1. FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 show an anti-vibration structure according to an embodiment of the present invention.

  As shown in FIG. 1, the vibration isolating structure includes a through hole 2 formed in the engine component 1, a bolt 3 that can be inserted into the through hole 2, and a boss 4 in which the bolt 3 is loosely fitted. It is mainly composed. The through-hole 2 has a size that allows only the male screw portion 5 of the bolt 3 to be inserted. The boss 4 is formed with a female screw hole 7 into which the male screw portion 5 of the bolt 3 is loosely screwed with a clearance 6. As shown in FIG. 2, the vibration isolating structure is configured by inserting the bolt 3 into the through hole 2 and then screwing the female screw hole 7 of the boss 4 into the male screw part 5 so as to have the clearance 6. The engine component 1 is gently held between the head 8 of the bolt 3 and the boss 4.

  In such an anti-vibration structure, when vibration is applied to the engine component 1, there is a clearance 6 between the male screw portion 5 of the bolt 3 and the boss 4, so that the bolt 3 moves relative to the boss 4. Thus, vibration energy is converted into heat energy, and vibration is reduced.

  Thus, since it is only necessary to attach the bolt 3 and the boss 4 to the constituent member 1 of the engine, vibration applied to the constituent member 1 can be reduced without increasing the cost and weight as compared with the related art.

In the above vibration damping, so as not to fall off from the boss 4 rotates and the bolt 3 by the vibration, Ru provided detent bolt 3. For example, as shown in FIG. 3, such a rotation stopper sandwiches a thin metal plate 9 between the head 8 of the bolt 3 and the constituent member 1, and bends the corner portion 10 of the thin plate 9. By bringing the surface of the thin plate material 9 into contact with one of the head side surfaces 11 of the bolt 3, it can be configured inexpensively and easily.

  Although the application object of the vibration isolating structure of the present invention is not particularly limited, it is preferably applied to a cylinder block, a head cover, an oil pan, pipes, or the like, which are engine components 1.

FIGS. 4 to 6 show the results of measuring the frequency response function (FRF) and the loss factor η when a specimen with an acceleration sensor attached to an aluminum head cover of the engine is suspended with a string and is vibrated by hammering. The total number of bolts attached to the test body and the presence or absence of clearance between the bolts and the bosses are changed as shown in Table 1. The loss factor η was calculated from the following equation (1).
η = (f2-f1) / f0 --- (1)
However, f0 shows a resonance frequency, f1 and f2 show the frequency which exhibits -3 dB with respect to the FRF level in f0, respectively.

  From the results of FIG. 4, it can be seen that Examples 1 and 2 have lower FRF and higher loss factor η than Comparative Examples 1 and 2. From the results of FIGS. 5 and 6, it can be seen that Example 1 significantly reduces the vibration of the specimen in a wide frequency range as compared with Comparative Example 1.

  From these results, it can be seen that the vibration-proof structure of the present invention has a vibration reduction effect. Furthermore, it can be seen from the results of FIG. 4 that even when the number of bolts in the vibration isolating structure of the present invention is as small as four, there is a certain vibration reducing effect.

DESCRIPTION OF SYMBOLS 1 Component 2 Through-hole 3 Bolt 4 Boss 5 Male screw part 6 Clearance 7 Female screw hole 8 Head 9 Thin plate material 10 Corner part 11 Head side

Claims (3)

An anti-vibration structure that reduces vibration applied to the member,
A through hole formed in the member; a bolt that can be inserted into the through hole; and a boss that loosely fits the bolt;
An anti-vibration structure characterized in that the boss is loosely fitted to the bolt inserted into the through hole , and a rotation stopper for the bolt is provided . The anti-vibration structure according to claim 1 , wherein the rotation stopper is formed by bending a part of a plate member sandwiched between the head of the bolt and the member and abutting against a side surface of the head of the bolt. The vibration isolation structure according to claim 1 or 2 , wherein the member is a constituent member of an engine.

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