JPS61275564A - Side branch type muffler - Google Patents

Abstract

PURPOSE:To facilitate assembling work while to satisfy different material characteristic by constructing a branch tube to be coupled in the way of gas conduit while coupling a pipe member to be coupled with the gas conduit and a pipe member having choked end. CONSTITUTION:In the intake system of internal-combustion engine for vehicle, an intake manifold 2 to be coupled with the engine body 1, a throttle body 3, an air-cleaner 4 and an intake tube 5 as gas conduit are coupled sequentially. In order to reduce noise in the intake system, a branch tube 6 and a resonator chamber 7 are coupled to the intake tube 5. Here, the branch tube 6 is constructed by coupling the first member 17 and the second pipe member 18 each other. The branch pipe 7 is extended forward from the joint with the coupling pipe 10 along the side of the engine body 1 while avoiding contact with other machineries and along the rear face of radiator 19. A bellows 20 is provided at the intermediate section of the first pipe member 17.

Description

DETAILED DESCRIPTION OF THE INVENTION 70 OBJECTS OF THE INVENTION (1) Field of Industrial Application The present invention relates to a side branch type muffler in which a branch pipe with a closed end is connected in the middle of a gas passage pipe.

(2) Prior Art Conventionally, such a silencer has been proposed, for example, in Utility Model Application Publication No. 48-327.
No. 3, No. 104, No. 104, No. 136, No. 136
No. 804, Utility Model No. 51-16144, Utility Model No. 56-1
It is well known from publications such as No. 381 '08 and Japanese Unexamined Patent Publication No. 55-51910.

(3) Problems to be Solved by the Invention In the above-mentioned silencer, depending on the frequency of the noise to be reduced, the length of the branch pipe may have to be increased. Assembly work becomes complicated.

Additionally, different material properties may be required at both ends of the branch pipe.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a side branch type muffling device that facilitates assembly work and can satisfy different material characteristics.

B0 Structure of the Invention (1) Means for Solving Problems According to the present invention, in the branch pipe, the first pipe member connected to the gas passage pipe and the second pipe member whose tip is closed are connected to each other. consists of being connected.

(2) Function Since the branch pipe is divided into the first and second pipe members, handling during assembly is facilitated. Furthermore, by forming both tube members from different materials, it becomes possible to satisfy different material characteristics at both ends.

(3) Embodiment Hereinafter, an embodiment in which the present invention is applied to an intake system of a vehicle internal combustion engine will be explained with reference to the drawings. First, in FIG. 1, an intake manifold 2 connected to an engine body 1, a throttle The body 3, the air cleaner 4, and the intake pipe 5 as a gas passage pipe are connected in this order to constitute an intake system of a vehicle internal combustion engine, and intake system noise is reduced (the intake pipe 5 is connected to a branch pipe 6 and A resonator chamber 1 is connected.

The intake pipe 5 has a first passage pipe 8 which is connected to the air cleaner 4 at one end and extends bent to the side of the throttle body 3, and a first passage pipe 8 which is connected to the air cleaner 4 at one end and extends in a bent direction to the side of the throttle body 3. It consists of a second passage pipe 9 that extends and bends toward the front, and a connecting pipe 10 that connects the first and second passage pipes 8 and 9, with the second passage pipe 9 opening toward the front of the vehicle. .

The resonator chamber 7 is connected to the lower part of the second passage pipe 9. That is, a connecting pipe section 12 extending obliquely downward is integrally provided at the lower part of the second passage pipe 9, and a neck section 14 of the resonator chamber T is connected to this connecting pipe section 12 via a rubber connecting pipe 13. Connected.

The branch pipe 6 is connected to a bent portion of the connecting pipe 10.

That is, the connecting pipe 10 is made of rubber, for example, and one end of the branch pipe 6 is fitted into a connecting pipe part 15 which is protruded from a bent part of the connecting pipe 10, and the connecting pipe part 15 is tightened from the outside. By tightening with the attaching member 16, the branch pipe 6 is connected to the connecting pipe 10.
connected to.

The branch pipe 6 is constructed by interconnecting the first pipe member IT and the second pipe member 18, and is bent while avoiding contact with other equipment from the connection part with the connecting pipe 10. , extends from the side of the engine body 1 toward the front, and is further bent to extend along the rear surface of the radiator 19.

The first pipe member 17 has one end connected to the connecting pipe portion 1 of the connecting pipe 10.
5 and is required to have impact resistance in order to maintain the connected state. Further, the intermediate portion of the first tube member IT has a bellows part. Therefore, the first tube member IT is formed by blow-molding a material that satisfies these requirements, such as a mixture of polypropylene and rubber.

Further, the second tube member 18 is supported by the radiator 19 and has one end connected to the first tube member 17, and the other end, that is, the tip is closed.

Since the second pipe member 18 is disposed near the exhaust manifold (not shown) of the engine body 1, it is desired that it has heat resistance.From this point of view, the second pipe member 18 is made of, for example, blown polypropylene. Formed by molding.

In FIG. 2, an enlarged diameter portion 21 is provided at one end of the second pipe member 18.
is provided, and the other end of the first tube member IT is connected to the enlarged diameter portion 2.
1 is fitted. Moreover, a pair of locking recesses 22 recessed outward in the radial direction are provided on the inner surface of the enlarged diameter portion 21 on a diameter line, and the locking recesses 22 are provided at the other end of the first tube member IT. An engaging protrusion 23 that can be engaged is provided in a protruding manner. Therefore, the first and second tube members 17.18 are directionally fitted, and the relative positions of the first and second tube members 17.18 are determined upon connection.

Next, to explain the operation of this embodiment, intake system noise is reduced by the functions of the resonator chamber 7 and the branch pipe 6, but when the branch pipe 60 is assembled, the fourth and second Since the pipe member is divided into two parts 17° and 18, it is easy to handle and assemble the pipe member. Furthermore, by dividing the branch pipe 60 into two, it is possible to provide different material properties to both ends of the branch pipe 60. Furthermore, when blow molding the first and second pipe members 17 and 18, a small mold is required (as opposed to a thick mold when integrally molding the branch pipe 6), which enables cost reduction. By dividing the complicated three-dimensionally shaped branch pipe 6 into the first and second pipe members 17 and 18 at the substantially two-dimensional portions, two-dimensional blow molding becomes possible and manufacturing costs are further reduced. Moreover, when integrally molded, it is difficult to make the wall thickness uniform and form the bellows part 20, whereas the first tube member 17 is relatively short and has some elasticity.
Since the bellows part 20 is provided in the bellows part 20, it is possible to form the bellows part 20 with uniform thickness and elasticity.

C0 Effects of the Invention As described above, according to the present invention, the branch pipe is formed by interconnecting the first pipe member connected to the gas passage pipe and the second pipe member whose tip is closed. Therefore, the installation work of the branch pipe becomes easy, and both ends can have different material properties, and further, manufacturing costs can be reduced.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to an intake system of a vehicle internal combustion engine, and FIG. 1 is an overall plan view, and FIG. 2 is an enlarged cross-section along the line ■-■ in FIG. 1. Cross section. 5... Intake pipe as a gas passage pipe, 6... Branch pipe,
1γ...first tube member, 18...second tube member, 20.
... bellows belly

Claims (2)

[Claims] (1) In a side branch type silencer in which a branch pipe with a blocked tip is connected in the middle of a gas passage pipe, the branch pipe has a first pipe member connected to the gas passage pipe and a branch pipe with a blocked tip. A side branch type silencer characterized in that the second pipe member is connected to the second pipe member. (2) The side branch type silencer according to claim (1), wherein one of the first and second pipe members is provided with a bellows portion.