JPH08177458A - Pipe structure of exhaust muffler - Google Patents

Abstract

PURPOSE: To decrease the number of parts of an exhaust muffler, to improve simplification, and to improve stiffness. CONSTITUTION: The length of a pipe 1 is so set that the pipe can be supported by at least two walls, two end plates for constituting a muffler A or an end plate and a partition wall plate in the muffler, and a blocking part 1a is formed by crunching the specified position of the pipe 1 by squeezing work. A plurality of holes 2, 3 for allowing exhaust gas to flow are formed on the peripheral walls 1b on one side or both sides of the blocking part 1a. One pipe can be made to function as a plurality of pipes since the function as the bulkhead is provided to the blocking part 1a, and the number of parts can be decreased. The end plate and the partition wall plate are made in common, and the working can be simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a pipe used in an exhaust muffler and allowing exhaust gas to flow inside the muffler.

[0002]

2. Description of the Related Art Exhaust silencers are classified into a single chamber and a plurality of chambers. In each case, the number of pipes is equal to the number of chambers plus one. Become.

As shown in FIG. 8, an exhaust silencer 51 having a single chamber is connected to an inflow pipe 51b through which exhaust gas from an engine flows into a cylinder 51a and a release pipe 51c for releasing the exhaust gas to the atmosphere. Has been done. In the exhaust silencer 51, when the inflow pipe 51b and the discharge pipe 51c face each other due to space problems, there is a possibility that the volume of the cylindrical body 51a cannot be effectively used.

In order to solve the above-mentioned problems,
Japanese Patent No. 61-192511 discloses a silencer for an internal combustion engine in which a separator having a large number of small holes is provided inside an inner chamber. This technology can reduce the exhaust pulsation in the silencer.

The exhaust silencer 52 shown in FIG. 9A is a cylindrical body 52.
It is configured such that the inflow pipe 52b and the discharge pipe 52c are connected to the end of a, the inside is divided into three chambers by two partition walls 52d and 52e, and the respective chambers are connected by distribution pipes 52f and 52g. ing. Further, the exhaust silencer 53 shown in FIG. 2B has an inflow pipe 53b and a discharge pipe at the end of the cylindrical body 53a.
53c is connected and the inside is divided into three partitions 53d to 53f,
It is divided into 4 chambers by a distribution pipe 53g between each chamber.
~ 53i are connected and configured.

In the exhaust silencer 52, 53 having a plurality of chambers constructed as described above, the exhaust gas is divided into partition walls 52e, 53d to 53f.
The distribution pipes 52g, 53g to 53i, which are circulated in the chambers on both sides, are supported only by the corresponding partition walls 52e, 53d to 53f.

[0007]

DISCLOSURE OF THE INVENTION Exhaust silencer of the above single chamber
In the case of 51, there is a problem that the volume of the cylindrical body 51a cannot be effectively utilized when the inflow pipe 51b and the discharge pipe 51c are arranged so as to face each other.
192511, or configured as disclosed in
As shown in FIG. 10, when the pipe ends of the inflow pipe 51b and the discharge pipe 51c are closed by the blind plug 51d, there is a problem that the number of parts increases.

Further, in the exhaust silencer 52, 53 having a plurality of chambers, the adjacent partition walls 52e, 53d to 53f are not connected to each other through a distribution pipe, and the rigidity may be insufficient in terms of performance and manufacturing. is there. In this case, it is necessary to connect the adjacent partition walls with a dummy pipe and reinforce the free end of the distribution pipe with an auxiliary component such as a patch. Therefore, there is a problem that the number of parts and the number of processing steps increase, which causes a cost increase.

An object of the present invention is to provide a pipe structure of an exhaust silencer, which is advantageous in terms of rigidity, in reducing the number of parts and simplifying processing when manufacturing the exhaust silencer.

[0010]

In order to solve the above problems, a pipe structure of an exhaust silencer according to the present invention is a pipe structure used for an exhaust silencer, and at least two pipes constituting the exhaust silencer are provided. It has a length that can be supported by a wall, and closes a predetermined position by crushing, and forms a hole through which exhaust gas flows on one or both wall surfaces of the closed part.

[0011]

[Function] The exhaust silencer (hereinafter simply referred to as "silencer")
In the pipe structure of (1), since the pipe has a length that can be supported by at least two walls (partition walls), it is possible to connect two adjacent partition walls by disposing the pipe inside the silencer. Therefore, it is possible to support the pipe at two points to improve stability and rigidity of the partition wall, and reduce the number of parts without the need for dummy pipes or auxiliary parts for fixing the free ends of the pipes. Can be done.

Further, since a predetermined position of the pipe is closed by crushing and holes for allowing exhaust gas to flow are formed on the wall surfaces (peripheral walls of the pipe) on both sides of the closed portion, one pipe has two or more holes. The function as a pipe of can be added. Therefore, the number of pipes can be substantially reduced without reducing the apparent number of pipes, and the number of parts can be reduced.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The pipe structure of the muffler will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a single-room silencer to which a pipe structure according to the present invention is applied, FIG. 2 is a diagram illustrating a step of closing a pipe by crushing, and FIG.
III-III is a cross-sectional view for explaining the shape of the closed part, FIG. 4 is a view showing another example of the step of closing the pipe, and FIG. 5 is the shape of the hole for circulating the exhaust gas formed in the peripheral wall of the pipe. FIG. 6 is a schematic sectional view of a three-room silencer to which the pipe structure according to the present invention is applied, and FIG. 7 is a schematic sectional view of a four-room silencer to which the pipe structure according to the present invention is applied. .

As shown in FIGS. 1, 5 and 6, the pipe structure of the muffler according to the present invention is a pipe 1 having a length that can be supported by at least two walls constituting an exhaust muffler.
A predetermined portion is closed by crushing to form a closed portion 1a, and a plurality of holes 2 and 3 for allowing exhaust gas to flow are formed in the peripheral wall 1b on one side or both sides of the closed portion 1a. Here, the crushing process is a so-called pressing process in which the pipe 1 is pressed and crushed in a diametrical direction by using a die, a so-called rolling process method in which the pipe 1 is pressed and crushed in a diametrical direction using a plurality of rotating rollers, It includes a swaging method for hitting the pipe 1 in the diameter direction to crush it, and a crushing process for inserting the pipe 1 into a die to reduce its diameter and then crushing the pipe 1 by each of the above-mentioned processes.

First, a single-room silencer A constructed by using the pipe 1 will be described with reference to FIG. In the figure,
The silencer A has a tubular body 11 having a predetermined thickness and length, and both ends of the tubular body 11 are closed by end plates 12, and the chamber 13 is formed by these tubular bodies 11 and end plates 12. Are formed. Holes through which the pipes 1 are inserted are formed at the opposite positions of the end plates 12, and the pipes 1 are arranged so as to penetrate the holes.

A closing portion 1a is formed at a position sandwiched by a pair of end plates 12 of the pipe 1, and a plurality of holes 2 and a plurality of holes 3 are formed in a peripheral wall 1b on both sides of the closing portion 1a. ing. The holes 2 and 3 are set according to the arrangement position and function of the silencer A of the pipe 1. Therefore, the holes 2 and 3 may have the same shape and size, or may have different shapes.

In the muffler A constructed as described above, since the pipe 1 is supported by the two end plates 12, it is possible to maintain a stable mounting position. Also, despite the fact that the exhaust gas inlet and outlet are arranged coaxially,
The inflowing exhaust gas is discharged from the hole 2 to the chamber along the arrow in the figure.
It flows into the inside 13 and is further discharged to the atmosphere through the hole 3.

Therefore, it is possible to effectively utilize the volume of the chamber 13 to exert the sound deadening function. Further, the function of the exhaust gas inflow pipe and the function of the exhaust gas can be exhibited by one pipe 1, and the end plate 12 can be shared. Therefore, it is possible to reduce the number of parts.

The closed portion 1a of the pipe 1 is formed by crushing. That is, as shown in FIG. 2 (a), a straight pipe having a predetermined diameter is cut into a predetermined length based on the conditions preset in the design stage corresponding to the silencer to be applied. As shown in FIG. 2B, the closed portion 1a can be formed by crushing a predetermined position of the cut pipe 1 by crushing.

The cross-sectional shape of the closed portion 1a is not particularly limited. For example, as shown in FIG.
The peripheral wall may be crunched in a straight line to form the closed portion 1a, or may have a shape intersecting from three sides in the same figure (b) or a shape intersecting from four sides as shown in the same figure (c). good.

However, when the crunch is made in a straight line, the size of the closed portion 1a is generally larger than the outer diameter of the pipe 1, and the work of inserting the pipe 1 into the hole formed in the end plate 12 is performed. There is a risk that the degree of freedom in doing this will decrease. That is,
The two end plates 12 cannot be inserted from one end side of the pipe 1 and must be inserted from both end sides. Therefore, it is preferable that the size of the closed portion 1a is smaller than the outer diameter of the pipe 1. Therefore, in this embodiment, the closed portion 1a is formed by crunching in a shape intersecting from the four sides shown in FIG.

When the closed portion 1a is formed on the pipe 1, it is not always necessary to directly crunch the pipe 1, and the pipe 1 shown in FIG.
As shown in (a), the position where the closed portion 1a is to be formed may be reduced in diameter in the previous step, and then the reduced diameter portion may be crunched to be closed. In this case, even if the diameter-reduced portion is crunched in a straight line, there is no possibility that the size of the closed portion 1a will be larger than the outer diameter of the pipe 1.

Further, depending on the applied silencer, the diameters of the exhaust gas inflow side and the exhaust side may be changed. In this case, as shown in FIG. 4B, preset diameters D and d
It is possible to prepare the different diameter pipe 4 having the above and crunch the reduced diameter portion of the different diameter pipe 4 to form the closed portion 4a.

In the closed portions 1a and 4a formed by crunching the pipes 1 and 4 as described above, it is difficult to completely seal the inside of the pipes 1 and 4 to completely prevent the exhaust gas from flowing. is there. Therefore, the closed portions 1a and 4a
Is blocked to such an extent that the exhaust gas leakage at the portions 1a and 4a does not impair the performance of the silencer.

The shapes of the holes 2 and 3 formed in the peripheral walls on one side or both sides of the closed portions 1a and 4a in the pipes 1 and 4 are not limited. That is, the holes 2 and 3 may be so-called holes, or may be louver-shaped holes as shown in FIG.

Next, another example of the silencer to which the pipe structure according to the present invention is applied will be described with reference to FIGS. 6 and 7.
In the drawings, the same parts and parts having the same functions are designated by the same reference numerals.

FIG. 6 is a schematic sectional view showing the construction of the silencer B having three chambers. In the figure, the muffler B has a cylindrical body 21, and inside the cylindrical body 21, two end plates 22 arranged at both ends and two partition plates 23 arranged inside the muffler 3 are provided. One room 24a ~
24c is formed. Further, the pipes 1 and 5 are arranged so as to penetrate the one end plate 22 and the two partition plates 23, and the pipe 25 is arranged so as to penetrate the two partition plates 23.

An exhaust pipe 26 from the engine is connected to one end of the pipe 1, and the other end is open to the chamber 24c. Further, the closed portion 1a is formed so as to be located in the chamber 24b, and is the connection side of the exhaust pipe 26 of the closed portion 1a and the chamber 1b.
The hole 3 is formed at a position corresponding to 24a, and the hole 2 is formed at a position corresponding to the chamber 24b. Therefore, pipe 1
Has opening portions corresponding to all the chambers 24a to 24c, and the closing portion 1a has the same function as the partition plate 23.

The pipe 5 has a closed portion 5a formed at one end thereof and an exhaust pipe 27 for discharging exhaust gas to the atmosphere at the other end thereof.
Is connected. A hole 3 is formed near the closed portion 5a of the pipe 5, the closed portion 5a is located in the chamber 24a, and the hole 3 is located in the chamber 24b.

In the silencer B constructed as described above, the exhaust gas introduced from the exhaust pipe 26 passes through the pipe 1 to the chamber 24a.
Is introduced into the chamber 24c by the pipe 25, enters the chamber 24b through the pipe 1 again, and is discharged to the atmosphere through the pipe 5.

The pipes 1 and 5 are supported by three partition plates 23 and one end plate 22. Therefore, the pipes 1 and 5 are stably supported by a plurality of fulcrums, and the partition plate 23
Will be connected by the three pipes 1, 5, 25, and the rigidity can be improved.

Further, in the conventional construction, four pipes were required, but it is possible to construct the pipes of two pipes 1 and 5 and one pipe 25 according to the present invention, which is three pipes. Can be reduced. Furthermore, since three pipes and pipes penetrate the same position of the two partition plates 23, it is possible to make the partition plates 23 common, which simplifies the processing and reduces the cost. It will be possible.

FIG. 7 is a schematic sectional view for explaining the structure of the silencer C having four chambers. As shown in the figure, the tubular body 21 has two end plates 22.
And four chambers 24 by the three partition plates 23 arranged inside
It is divided into a to 24d. The pipe 1 is arranged so as to penetrate through the three partition plates 23, and the pipe 6 is arranged so as to penetrate through the three partition plates 23 and the two end plates 22.

The pipe 1 is arranged so that one end is located in the chamber 24a and the other end is located in the chamber 24d.
The closed portion 1a of the pipe 1 corresponds to the chamber 24C, and the holes 2 and 3 formed on both sides of the closed portion 1a are the chambers 24c and 24, respectively.
It has an opening at b. Therefore, the closed portion 1a is provided in the chamber 24b
It has the same function as the partition plate 23 that partitions c.

The pipe 6 is formed with closed portions 6a and 6b at two places, and holes 2 and 2 are provided on both sides of the closed portions 6a and 6b, respectively.
3 are formed. One end of the pipe 6 is an exhaust pipe 26
And the other end is connected to the discharge pipe 27.
The closed portions 6a and 6b are arranged so as to be located in the chambers 24b and 24d, and these closed portions 6a and 6b are respectively connected to the chamber 24a.
It has the same function as the partition plate 23 that divides the chamber 24b and the chambers 24c and 24d. Further, the holes 2 and 3 formed on both sides of the respective closed portions 6a and 6b are arranged so as to be located in the chambers 24a to 24d.

In the silencer C constructed as described above, the exhaust gas is sequentially introduced from the chambers 24a to 24d by the pipes 6 and 1, and is discharged from the pipe 6 to the atmosphere.

In the above-mentioned silencer C, five pipes, which were conventionally required, can be composed of two pipes 1 and 6, and the number of parts can be reduced. Further, since the two pipes 1 and 6 penetrate through the same position of the three partition plates 23, it is possible to make the partition plates 23 common, which simplifies the processing and reduces the cost. Is possible.

[0038]

As described above in detail, in the pipe structure of the muffler according to the present invention, a predetermined position of a pipe having a length that can be supported by at least two walls is crunched by crushing to form a closed portion. In addition, by forming a hole through which exhaust gas circulates on one side or both sides of the closed portion, the closed portion functions as a partition wall, thereby imparting the function of one pipe as a plurality of pipes. You can Therefore, the number of parts constituting the silencer can be reduced.

Since the pipe is supported by at least two walls, it is possible to connect end plates constituting the silencer or adjacent partition plates to each other by this pipe.
Therefore, it is possible to stably support the pipe and improve the rigidity of the partition plate. Therefore, an auxiliary part for increasing the rigidity of the partition plate and an auxiliary part for supporting the pipe are not required, and the number of parts can be reduced.

Since the pipe is arranged so as to penetrate through the plurality of end plates and / or partition plates, the end plates and the partition plates can have the same shape. Therefore, the parts can be shared and the manufacturing work can be simplified, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a single-room silencer to which a pipe structure according to the present invention is applied.

FIG. 2 is a diagram illustrating a step of closing a pipe by crushing.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2, illustrating the shape of the closed portion.

FIG. 4 is a diagram showing another example of the step of closing the pipe.

FIG. 5 is a diagram illustrating a shape of a hole formed in a peripheral wall of a pipe for allowing exhaust gas to flow therethrough.

FIG. 6 is a schematic cross-sectional view of a silencer with three chambers to which the pipe structure according to the present invention is applied.

FIG. 7 is a schematic cross-sectional view of a silencer with four chambers to which the pipe structure according to the present invention is applied.

FIG. 8 is a schematic cross-sectional view of a conventional single-room silencer.

FIG. 9 is a schematic cross-sectional view of a conventional silencer having a plurality of chambers.

FIG. 10 is a diagram illustrating a problem of a conventional single-room silencer.

[Explanation of symbols]

 A, B, C Silencer 1, 4, 5, 6 Pipes 1a, 4a, 5a, 6a, 6b Closing part 1b Peripheral wall 2, 3 Holes 11, 21 Cylindrical body 12, 22 End plate 13, 24a-24d Chamber 23 Partition wall Plate 25 pipe 26 exhaust pipe 27 discharge pipe

Claims (1)

[Claims] 1. A structure of a pipe used for an exhaust silencer, having a length that can be supported by at least two walls constituting the exhaust silencer, and closing a predetermined position by crushing and closing the same. A pipe structure for an exhaust silencer, characterized in that holes are formed in one or both wall surfaces for allowing exhaust gas to flow therethrough.