JPH0241293Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention prevents cracks from occurring in the bent pipe, partition plate, etc. due to thermal expansion of the bent pipe penetrating the partition plate in an expansion type silencer. This article relates to an engine silencer structure designed to prevent

(Prior art) The interior of the silencer is partitioned into multiple chambers, and each time the exhaust gas enters each chamber, it expands and muffles the sound. Inside the expansion type silencer, the pipe is bent into a U-shape and placed long. , is known to increase the silencing effect. (For example, Utility Model Application Publication No. 55-59119) In this case, if the pipe passes through the partition plate in two places and fixes both of the penetration parts, there is a risk that cracks will occur in the fixed part due to elongation due to thermal expansion of the pipe. Therefore, it has been common practice to have one side fixed and the other movable without being fixed so as to allow the pipe to extend in the axial direction.

(Purpose of the invention) In such a case, if the pipe is straight, the conventional method will suffice, but if the bent part of the bent pipe straddles the partition plate, the direction of deformation due to thermal expansion of the bent pipe is not constant, so the conventional method is sufficient. It is not enough to provide a guide that can move in only one direction, and the purpose of this proposal is to prevent cracks that are likely to occur in partition plates and bent pipes in response to the inconsistent deformation direction of such bent pipes. It is something.

(Structure of the invention) In order to achieve the above purpose, the interior of the silencer is divided into a plurality of compartments by a partition plate, and a long exhaust passage is constructed by providing a bent pipe that penetrates the partition plate. In the engine silencer, at least one of the two through holes formed in the partition plate that spans the bent portion of the bent pipe is provided with a central A ring-shaped intermediate member having a guide hole through which the bent pipe is inserted,
It is slidably provided along the plate surface of the partition plate to allow movement of the bent pipe in the axial direction and in the direction of the partition plate.

With this configuration, even if the bent part of the bent pipe is deformed in any direction due to thermal expansion, it can move in a direction perpendicular to the partition plate and in a direction parallel to the partition plate, making it possible to create a universal support structure. Since the structure allows deformation in all directions, it is possible to prevent cracks from occurring due to excessive strain on the bent pipe and partition plate.

(Example) Hereinafter, the configuration of the present invention will be explained based on the drawings illustrating the embodiment.

1 is a silencer outer cylinder, which is sealed by caulking or welding both end plates to the cylinder body. 2 and 3 are partition plates that divide the inside of the silencer into a first compartment 4,
It is divided into a second compartment 5 and a third compartment 6. 7 is an exhaust pipe, which is connected to the exhaust manifold and directs the engine exhaust to the second compartment 5 in the direction of the arrow.
This will be introduced in the future. A communication port 8 communicates from the second compartment 5 to the third compartment 6. 9 is a communication pipe that connects the third compartment to the first compartment. Reference numeral 10 is a bent pipe bent twice at 180° into an S-shape, and the intermediate part 10a is connected by welding, and one end is opened in the first compartment 4, and the second compartment 5 and the third compartment 6 are connected to each other by welding.
The tail portion protrudes to the outside of the silencer outer cylinder 1 by penetrating the partition plates 2 and 3 at three locations.

The first bent part 10b of this bent pipe 10 is connected to the partition plate 3, and the second bent part 10c is connected to the partition plate 2.
It is inserted through two through holes 11 and 12 provided respectively, and one of the through holes 11 has an overhanging edge so that the bent pipe 10 can easily move in the axial direction, as shown in FIG. be. The other one of the through holes 12 has a slightly larger diameter as shown in FIG. Ring-shaped intermediate member 1 with a letter-shaped cross section
3, the U-shaped cross-section side plates sandwich the partition plates 2 and 3 around the through hole 12, and the diameter of the through hole 12,
A gap is formed between the diameter of the bottom of the U-shape of the intermediate member 13, and the intermediate member 1 is
3 can freely slide along both sides of the partition plates 2 and 3.

The means for the intermediate member 13 to fit around the through holes 12 of the partition plates 2 and 3 is as shown in phantom lines in FIG. It can be easily formed by manufacturing it in the shape of a bush, passing the cylindrical part through the through hole 12, applying the collar part to one side of the partition plates 2 and 3 around the through hole 12, and folding the cylindrical part in the direction of the arrow. .

In FIG. 1, the intermediate member 13 is interposed only at part B of one of the bent parts of the bent pipe 10,
Although the other A section is shown as being able to move only in the axial direction of the bent pipe 10, the A section may also have an intermediate member interposed therebetween like the B section.

As shown in FIG. 1, in the silencer configured in this way, the exhaust gas sent from the exhaust pipe 7 first enters the second compartment 5 and expands for the first time, and then passes through the communication port 8 to the third compartment. The long bent pipe 10 enters the chamber 6 and expands for the second time, then enters the first compartment 4 through the communication pipe 9 and expands for the third time. The sound is discharged from the tail portion to the outside of the silencer outer cylinder 1 through the long bent pipe 10, and the sound is further attenuated while passing through the long bent pipe 10.

When the silencer functions in this way, the bent pipe 10 in particular is easily deformed by heat, and this deformation extends in the axial direction in the straight part, but the first bent part 10
Since the deformation direction of the portions b and the second bent portion 10c is not constant, deformation cannot be tolerated only by the configuration of the portion A shown in FIG. If the intermediate member 13 is interposed between the bent pipe and the partition plate as shown in part B shown in FIG. The partition plates 2, 3 and the bending pipe 10 can be configured to form a universal support part, allowing the deformation of the bending pipe 10 no matter how it deforms.
No excessive force is applied to the material, and cracks will not occur.

(Effects of the invention) According to the invention described above, the bending pipe installed inside the silencer by penetrating the partition plate has a simple structure, and there are problems such as cracks in the partition plate and the bending pipe due to deformation due to thermal expansion. This makes it possible to obtain a highly durable engine silencer structure.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view showing one embodiment of the silencer of the present invention, Fig. 2 is an enlarged detailed view of section A in Fig. 1,
FIG. 3 is also an enlarged detailed view of section B in FIG. 1. 1... Silencer outer cylinder, 2, 3... Partition plate,
4...First compartment, 5...Second compartment, 6...Third compartment, 7...Exhaust pipe, 8...Communication port, 9
...Communication pipe, 10...Bend pipe, 11,1
2...Through hole, 13...Intermediate member.

Claims (1)

[Scope of utility model registration request] In an engine silencer having an interior divided into a plurality of compartments by a partition plate and a bent pipe passing through the partition plate, one of two through holes formed in the partition plate across which the bent portion of the bent pipe extends. , one of the through holes is located at a distance between the through hole and the bent pipe and allows movement of the bent pipe only in the axial direction, and the other through hole allows movement only in the direction of the partition plate. An engine silencer structure characterized by providing a permissive intermediate member.