JPS6233972Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a sound insulation structure for a case that is suitable for cases such as engines and transmissions for small vehicles such as motorcycles, and is a sound insulation structure that has good sound insulation performance and is easy to assemble. The purpose is to obtain.

This type of sound insulation structure is already known in Japanese Utility Model Application Publication No. 56-46195, Japanese Patent Application Publication No. 57-8319, etc. However, these methods use parts with complex shapes and require a large number of assembly steps, which is not desirable for mass production.

This idea was made to eliminate the above-mentioned problems. The embodiments shown in the drawings will be explained below. 1 is a case that forms part of the crank chamber of a motorcycle, and there is a roughly circular depression 1 in the center of its outer surface.
As shown in FIG. 2, an engagement groove 2 is formed on the inner circumferential surface of the recess 1a. 3 is an outer lid that closes the recess 1a. The outer cover 3 has a circumferential groove 3a on its outer periphery, and a rubber-like vibration isolator 4 formed in an annular shape is fitted into the circumferential groove 3a. The vibration isolating material 4 is provided with a clip groove 4a on its outer periphery, and a gap between the clip groove 4a and the engagement groove 2 formed on the inner peripheral surface of the recess 1a is made to have a diameter slightly larger than the inner diameter of the recess 1a. It is held in place by a clip 5 in the shape of an occluded circle.

A rubber O-ring 6 is held between the bottom of the recess 1a and the outer lid 3, and is positioned by an annular projecting wall 1b provided at the bottom. Note that 1c is a soundproofing material adhered to the inner surface of the case 1.

In FIG. 2, numeral 7 indicates an assembly tool for the outer cover 3. That is, the assembly tool 7 has a hole 7a having approximately the same diameter as the depression 1a, and a chamfered portion 7b above the hole 7a. Therefore, when assembling the outer cover 3, the vibration isolating material 4 and the clip 5 are fitted to the outer cover 3 in advance, the assembly tool 7 is applied to the outside of the recess 1a, and the outer cover 3 is attached to the chamfered portion 7b. By placing the clip 5 on the clip 5 and pushing it from above into the recess 1a, the outer periphery of the clip 5 is elastically compressed by the chamfered portion 7b, and the clip 5 can be smoothly inserted into the recess 1a. When the clip 5 reaches the engagement groove 2, it expands elastically and engages therein. At the same time, the O-ring 6 is compressed between the bottom of the recess 1a and the outer cover 3, thereby mutually suppressing vibrations generated therein.

As described above, this invention includes providing a substantially circular depression 1a on the outer surface of the case 1, forming an engagement groove on the inner peripheral surface of the depression 1a, and forming a circumferential groove on the outer periphery of the outer cover that closes the depression. A clip groove is provided on the outer periphery of the rubber-like vibration isolator that is engaged with the circumferential groove, and a circular clip is used to lock between the clip groove and an engagement groove formed on the inner circumferential surface of the recess. Therefore, the case 1 has increased rigidity by forming the depression 1a,
Vibration on the surface is reduced and noise radiated to the outside is reduced. In addition, even if the bottom of the recess 1a, which has a relatively large area, vibrates and generates noise due to internal vibrations, the outer surface of the recess 1a is made separately from the case 1 and supported elastically. Sound is insulated by the outer cover 3, and radiation to the outside is significantly reduced. Therefore, good sound insulation performance can be obtained. Furthermore, when assembling the engine, the assembly can be carried out by simply applying the assembly tool 7 to the outer surface of the case 1, placing the outer cover 3 on the chamfered part 7b, and pushing it from above into the recess 1a. It can be completed on time and is well suited for assembly by conveyor line.
There are effects such as ease of assembly work.

[Brief explanation of the drawing]

The drawing shows an example of this invention.
FIG. 1 is a sectional view of the case 1, FIG. 2 is an enlarged sectional view of the main part thereof, and FIG. 3 is an external view of the clip 5, which is the main part of this invention. 1... Case, 1a... Recess, 2... Engagement groove,
3... Outer lid, 3a... Circumferential groove, 4... Vibration isolating material, 5...
...Clip, 7... Assembly tool.

Claims (1)

[Scope of utility model registration request] A substantially circular depression 1a is provided on the outer surface of the case 1, an engagement groove is formed on the inner peripheral surface of the depression 1a, a circumferential groove is formed on the outer periphery of an outer lid that closes the depression, and the groove is engaged with the circumferential groove. A sound insulating structure for a case in which a clip groove is provided on the outer periphery of a rubber-like vibration isolator, and the clip groove is engaged with an engagement groove formed on the inner circumferential surface of the recess with a circular clip.