JPH05141237A - Exhaust pipe structure - Google Patents

Abstract

PURPOSE:To reduce a synthetic vibration of an exhaust pipe and a muffler and an influence of this vibration given to a vehicle. CONSTITUTION:An exhaust pipe line is formed of an exhaust pipe 1 and a muffler 5 connected to a downstream end part 3a of this exhaust pipe 1, and suspension parts 2b, 7b, 5b protrusively provided respectively on external surfaces of the exhaust pipe 1 and the muffler 5 are hook-supported by elastic members 8 to suspend the exhaust pipe 1 and the muffler 5. In this exhaust pipe structure, a rubber-made pipe joint 11 having low elasticity and heat resistance is interposed in the exhaust pipe line formed between the suspension part 2b protrusively provided on the exhaust pipe 1 and the muffler 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust pipe structure for mounting an exhaust pipe used in a vehicle such as a passenger car so that vibrations thereof are not transmitted to other parts.

[0002]

2. Description of the Related Art Conventionally, as an exhaust pipe structure of this type, vibrations of an exhaust pipe system including a muffler are transmitted to a vehicle as disclosed in Japanese Utility Model Publication No. 56-35421 and Japanese Utility Model Publication No. 57-32519. In order not to do so, it is known that the upstream side and the downstream side of the muffler or both side surfaces of the muffler and the front pipe of the exhaust pipe are suspended by elastic members on the lower surface of the vehicle. The elastic member is generally composed of a rubber O-ring. Further, some diesel engine vehicles use a flexible pipe in a portion connecting the engine side and the front pipe.

[0003]

However, there is an engine at the front of the vehicle, and the exhaust pipe system for guiding the gas discharged from the engine to the rear of the vehicle is long, and the vibration at the front and the vibration at the rear are different in intensity and frequency. However, even if the vehicle is suspended by an elastic member, its vibration may affect the vehicle. Considering this, an attempt has been made to reduce the influence of vibration by using a spring constant of the elastic member, but the adjustment is not effective even though it takes time. Also, in the case of using a flexible pipe, the vibration is separated at this portion, but in order to sufficiently suppress the vibration, it is necessary to lengthen the total length of the flexible pipe and reduce the spring constant, but the total length is If it becomes longer, more space will be required, and the material cost will be higher, and there is room for improvement.

An object of the present invention is to eliminate such a problem.

[0005]

The present invention takes the following means in order to achieve such an object. That is, in the exhaust pipe structure according to the present invention, the exhaust pipe forming the exhaust pipe line and the muffler connected to the downstream end of the exhaust pipe are provided on the outer surface of the exhaust pipe and the muffler, respectively. In an exhaust pipe structure in which a suspension part is suspended by an elastic member, the exhaust pipe line formed between the suspension part protruding from the exhaust pipe and the muffler has low elasticity and heat resistance. It is characterized in that it has a rubber pipe joint that it has.

[0006]

With this structure, the muffler is elastic by the pipe joint to the vibration system of the exhaust pipe system composed of the exhaust pipe and the muffler supported by elastic members. By being electrically connected, it acts as a mass damper. Therefore, since the natural frequency of the vibration system can be changed, the deterioration of the vibration level due to the natural mode of the exhaust pipe can be significantly improved, and it is transmitted to the vehicle that suspends the exhaust pipe and the muffler in that frequency range. Vibration can be reduced. As a result, noise in the vehicle compartment can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, an exhaust pipe 1 forming a part of an exhaust pipe line for leading out exhaust gas from an engine (not shown) to the outside is composed of a front pipe 2 and a tail pipe 3 in this order from the side closer to the engine. Has been done. A main muffler 5 is connected to the downstream end 3 a of the tail pipe 3 via a pipe joint 4. In the figure,
Reference numeral 6 denotes a vehicle floor panel (not shown). The vehicle in this embodiment is of a type in which an engine is placed in front of the vehicle and the exhaust pipe 1 is extended rearward, as represented by a passenger car. In a vehicle of this type, the length of the front pipe 2 is, for example, about three times longer than the length of the tail pipe 3, the pipe joint 4 and the main muffler 5.

The front pipe 2 has a hook-shaped rod member 7b which is a suspension portion projecting from the upper outer surface 7a of the upstream end of the sub-muffler 7 which is interposed in the middle portion, and the downstream end 2a. Hook-shaped rod-shaped member 2 that is a suspended portion that projects in the vicinity
b is suspended from the floor panel 6 by being supported by a hook-shaped rod-shaped member 9 protruding from the lower surface of the floor panel 6 via an elastic member 8. A flange 2c is fixedly installed on the downstream end 2a of the front pipe 2.
The tail pipe 3 is connected to c by bolts and nuts not shown.

A rubber pipe joint 4 connected to the downstream end 3a of the tail pipe 3 and having low elasticity and heat resistance.
Is made of silicone rubber and has a spring constant of 0.01 or less,
The pipe is preferably 0.002 to 0.004, and more preferably 0.0035. As shown in FIG. 2, one end is fitted with the downstream end 3a of the tail pipe 3, and the other end is fitted. The connecting pipe 5a of the main muffler 5 is fitted in the portion. In this case, the distance L between the downstream end 3a of the tail pipe 3 and the connecting pipe 5a of the main muffler 5 within the pipe joint 4 is preferably about 10 mm. The contact area increases, which is not preferable, and conversely, when the area is reduced, the desired spring constant cannot be obtained, which is not preferable. Thus, the pipe joint 4 is interposed in the exhaust pipe line formed between the main muffler 5 and the rod-shaped member 2b projecting from the front muffler 2 that constitutes the exhaust pipe 1. Each end of 4 is clamped by a strip clamp 10. Like the front pipe 2, the main muffler 5 connected to the pipe joint 4 includes a bar-shaped member 5b protruding on the outer surface thereof, an elastic member 8 and a hook-shaped bar-shaped member 9 protruding from the floor panel 6 for the floor panel. Suspended at 6. As the elastic member 8 used for the fishing rod of the front pipe 2 and the main muffler 5, a widely known member such as a rubber O-ring in the relevant field can be used.

In the above structure, the pipe joint 4 is preferably attached at a position close to the main muffler 5 in consideration of the fact that the high temperature use limit is about 280 ° C. made of silicone rubber and the action of the mass damper is taken into consideration. In other words, in terms of heat, if the heat from the engine (not shown) conducted by the front pipe 2 and the sum of the temperatures of the exhaust gas added thereto are below the above-mentioned high-temperature use limit, it is not necessarily upstream of the main muffler 5. From the viewpoint of the mass damper, it is not necessary to be in the vicinity, but it is preferable that it is closer to the main muffler 5 that is a mass and downstream of the fishing position on the side of the front pipe 2 closer to the main muffler 5. At such a mounting position, a mass damper is constituted by the pipe joint 4 and the main muffler 5, and the mass damper of the exhaust pipe system E including the front pipe 2 including the sub muffler 7, the tail pipe 3, the pipe joint 4 and the main muffler 5. It acts to change the natural frequency and reduce specific vibrations. That is, when the exhaust pipe system E vibrates due to the vibration from the engine,
The pipe joint 4 is elastically deformed by the vibration of the main muffler 5. Due to the elastic deformation of the pipe joint 4, the exhaust pipe system E
The natural frequency of is changed and the specific vibration is reduced. Therefore, due to the effect of reducing the vibration of the exhaust pipe system E, the vibration level transmitted via the elastic member 8 supporting the front pipe 2 and the main muffler 5 becomes low, and the level of vehicle interior noise is increased. Is prevented.

The present invention is not limited to the embodiment described above, and the material of the pipe joint 4 may be fluororubber having a high temperature use limit of about 300 ° C., or a metal mesh. It may be a formed pipe. Also in the case of these materials, the spring constant is 0.01 or less, preferably 0.00, as in the above embodiment.
The thing in the range of 2-0.004 is used.

Besides, the configuration of each part is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0014]

As described in detail above, according to the present invention, a muffler is exhausted by a pipe joint with respect to an oscillating system of an exhaust pipe system composed of an exhaust pipe and a muffler which are respectively supported by elastic members. Since it acts as a mass damper by being elastically connected to the pipe, the natural frequency of the vibration system can be changed. As a result, the deterioration of the vibration level due to the eigenmode of the exhaust pipe system can be greatly improved,
It is possible to reduce the vibration transmitted to the vehicle that suspends the exhaust pipe and the muffler in that frequency range, and it is also possible to reduce the noise in the vehicle compartment.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical sectional view of a main part of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Exhaust pipe 2 ... Front pipe 2b ... Rod-shaped member 3 ... Tail pipe 3a ... Downstream end 4 ... Pipe joint 5 ... Main muffler 5b ... Rod-shaped member 8 ... Elastic member

Claims (1)

[Claims] 1. An exhaust member, which forms an exhaust pipe line, and a muffler connected to a downstream end portion of the exhaust pipe are provided with elastic members as suspension parts projectingly provided on the outer surface of the exhaust pipe and the muffler, respectively. In an exhaust pipe structure that is suspended and suspended, a rubber pipe joint having low elasticity and heat resistance is provided in an exhaust pipe line formed between a muffler and a suspension part protruding from the exhaust pipe. An exhaust pipe structure characterized by being inserted.