JPH0332745Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field of the Invention The present invention relates to an improvement of an exhaust system support structure for a vehicle internal combustion engine.

(b) Background of the Technology In the exhaust system of a vehicle internal combustion engine, especially the exhaust system of a truck, the exhaust system members are supported on the vehicle body at multiple locations because the length of the exhaust system is long.

However, since the parts of the exhaust system, including the exhaust pipe and muffler, are connected without very precise mechanical work, dimensional errors occur in the direction of the tail end of the exhaust system. The position of the support portion on the vehicle body may be misaligned, and effective support may not be provided. Therefore, the development of a support structure that can absorb such displacement of the support portion is expected.

On the other hand, in the exhaust system of a vehicle internal combustion engine, forced vibration from the engine is added to the natural vibration of the exhaust system, causing a resonance phenomenon and generating vibration radiation sound.
Therefore, from the standpoint of noise prevention measures, it is required to reduce this vibration radiated sound.

(c) Prior Art and Problems Conventionally, support structures for exhaust systems shown in FIGS. 2 to 4 have been provided based on the above-mentioned technical background.

Fig. 2 shows an exhaust system 2 connected by a flange 1 to an exhaust manifold M connected to an engine E. The exhaust system 2 consists of an exhaust pipe 2a and a front tube 2a', each consisting of a front tube 2a' and a tail tube 2a''. , and a muffler 2b provided between the tail tube 2a'' and the tail tube 2a''. In this conventional example, the exhaust system 2 is supported on the vehicle body S by a plurality of elastic support members 3 such as spring members.

According to this conventional example, since the exhaust system 2 is supported on the vehicle body S by the elastic support member 3, even if the position of the support part shifts as described above, the deformability of the elastic support member 3 can be used to It has the advantage of being able to absorb this and provide effective support.

However, since the vibrations of the engine E are transmitted to the exhaust system via the exhaust manifold M, there is a problem in that vibration radiated noise cannot be expected to be reduced.

In the conventional example shown in FIG. 3, an exhaust manifold M and a front tube 2a' are connected by a flexible tube 2c.
c. The connecting portion of the front tube 2a' is supported on the vehicle body S by a fixed support member 4, and other appropriate locations of the exhaust system 2 are also supported by fixed support members 4.

According to this conventional example, the flexible tube 2
c. Since the connecting portion of the front tube 2a' is supported on the vehicle body S by the fixed support member 4, the vibration isolation function of the flexible tube 2c is effectively exerted to prevent vibrations of the engine E from being transmitted to the exhaust system 2. death,
Further, there is an advantage that the durability of the flexible tube 2c is ensured. Regarding this point, there is an example of literature such as Utility Model Application Publication No. 57-150216.

However, although the use of the fixed support member 4 in other parts of the exhaust system 2 as in this conventional example is useful for the flexible tube 2c described above, it does not provide a structure that absorbs misalignment of the support part. Therefore, there is a problem that effective support cannot be provided.

The conventional example shown in Fig. 4 is similar to Figs.
It is a combination of the conventional example shown in the figure, and the use of the elastic support member 3 is common to the conventional example shown in FIG.
The use of a flexible tube 2c is common to the conventional example shown in FIG.

This conventional example has the advantage of solving the problems of the conventional examples shown in FIGS. 2c
There is a problem that the durability of

(d) Purpose of the invention The purpose of the invention is to improve the mountability and durability of a support structure that reduces vibration and radiated sound.

(e) Structure of the invention In order to achieve this object, the exhaust system support structure for a vehicle internal combustion engine according to the invention is such that the exhaust system members are supported on the vehicle body at multiple locations, and the exhaust manifold and exhaust pipe are formed into flexible tubes. In an exhaust system support structure for a vehicle internal combustion engine that is connected with The present invention is characterized in that a plurality of elastic support members are provided, and the elastic support members are constituted by elastic members whose elastic modulus gradually decreases toward the tail end of the exhaust system.

(F) Embodiments of the invention An embodiment of the exhaust system support structure for a vehicle internal combustion engine according to the invention will be described below with reference to FIG.

As shown in FIG. 1, the present invention connects an exhaust manifold M and a front tube 2a' with a flexible tube 2c.
A supporting member 4 fixes the connecting part of the front tube 2a'.
The elastic support member 3 supports the other supporting parts on the vehicle body S.

In addition, in the present invention, the elastic modulus of the elastic support member 3 is gradually decreased toward the tail end of the exhaust system 2. That is, the elasticity is made smaller in the order of the elastic support member 3a near the fixed support member 4 shown in FIG. 1, the intermediate elastic support member 3b, and the elastic support member 3c of the tail tube 2a''.

When the elastic support member 3 is made of a spring material, the elasticity can be easily adjusted by changing the number of turns of the spring, and even when other elastic members are used, the adjustment can be performed with extremely simple techniques. The modulus of elasticity can be adjusted depending on the members of the exhaust system 2 (the front tube 2a' , tail tube 2a'', muffler 2b), weight, etc.

From the above, since the fixing force to the flexible tube 2c becomes progressively softer from the leftmost elastic support member 3a in the drawing toward the tail end support member 3c,
To improve the durability of the flexible tube 2c by reducing stress such as vibration of an exhaust system 2 acting on the flexible tube 2c, and to effectively exhibit the function of the flexible tube 2c to reduce transmission of vibrations of an engine E. become. Further, the above-mentioned positional deviation of the support portion increases sequentially toward the tail end of the exhaust system 2, but the elastic modulus of the elastic support member 3 decreases in proportion to this, and deformability also increases. Therefore, the deviation can be completely absorbed.

(g) Effects of the invention As described above, the exhaust system support structure for a vehicle internal combustion engine according to the invention effectively fixes and functions the flexible tube, so it has the effect of reducing vibration radiated sound and improving durability. be. In addition, the displacement absorbing ability of the support member corresponding to the degree of displacement, in which the displacement of the support portion increases sequentially toward the tail end of the exhaust system 2, corresponds to deformation by gradually decreasing the elastic coefficient of the elastic support member. Since the capacity is increased and the exhaust system members are increased in number, there is an effect of improving the ease of attaching the exhaust system members.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of an exhaust system support structure for a vehicle internal combustion engine according to the present invention, and FIGS. 2 to 4 are side views showing conventional examples. 2... Exhaust system, 2a... Exhaust pipe, 3... Elastic support member, 4... Fixed support member, E... Engine,
M...exhaust manifold, S...car body.

Claims (1)

[Scope of utility model registration request] In an exhaust system support structure for a vehicle internal combustion engine in which the exhaust system components are supported by the vehicle body at multiple locations and the exhaust manifold and exhaust pipe are connected by a flexible tube, the joint between the exhaust pipe and the flexible tube is fixed to the vehicle body. In addition to the fixed support member, a plurality of elastic support members are provided for the exhaust system member to the vehicle body, and the elastic support member has an elastic modulus that gradually decreases toward the tail end of the exhaust system. 1. An exhaust system support structure for a vehicle internal combustion engine, characterized in that it is comprised of members.