JPH08210206A - Muffling device - Google Patents

Abstract

PURPOSE: To precisely form an opening inside an expanding room, though space and axis adjusting work is not required, and to simplify assembly work to the utmost limits. CONSTITUTION: This muffling device is composed of a case body 1; which is consisted of case parts 13, 14 containing a partition wall 15, a first cylindrical part 11 integrally die formed with the case parts 13, 14 and containing an one end opening opened on an expanding room A, and a second cylindrical part 12 integrally die formed in a similar manner, containing a a resonator opening 16 on the wall represented on a resonator room B, opposing with a gap between the one end opening 11a opened on the expanding room A, and containing an one end opening 12a opened on the expanding room A; and a cover body 2 fixed to the case body 1. Because the opening part is integrally formed with the case body 1, assembly is not required and the precision of the opening part is secured, and because the components are only the case body 1 and the cover body 2, assembly work can be simplified to the utmost limits. Thus it is inexpensive but trouble is not easily developed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffler for forming an expansion chamber, and more particularly to a muffler suitable for reducing noise such as pulsating noise in an intake system of a piston engine of an automobile or the like.

[0002]

2. Description of the Related Art As a conventional silencer, for example, Japanese Patent Publication No.
As described in Japanese Patent No. 4-40265, a hose having an opening on a wall surface and a case formed by blow molding that defines an expansion chamber that covers the portion including the opening and opens the opening. It has been known.

[0003]

In blow molding, the shape of a case that can be molded is limited, and there is a limit in obtaining a case that can be stored in a narrow engine room and has a predetermined performance. Therefore, the present applicant invented a silencer formed by injection molding and filed a patent application as Japanese Patent Application No. 6-199821. As shown in FIG. 4, the silencer described in the specification of the present application has a first cylindrical portion 103 having one end open to the internal space and a mounting hole 107 communicating with the internal space. Main body 1 integrally formed by injection molding to partition a part of space
00, a closing portion 102 formed by injection molding that is coupled with the main body portion 100 to form the internal space, and the mounting hole 1
The second tubular portion 10 that is mounted on 07 and has one end facing the one end of the first tubular portion 103 with an interval 110 in the internal space.
It consists of 5. This internal space is divided into two by a partition wall 101 to form an expansion chamber A and a resonator chamber B.

The expansion chamber A effectively exerts a silencing effect on noise in a wide frequency band such as pulsating sound, and the resonator chamber B exerts an excellent silencing effect on noise in a specific frequency band. Therefore, this muffler is designed so that the effects of both the expansion chamber A and the resonator chamber B are combined to exert an excellent muffling effect. However, in this silencer, when the opening end of the second tubular portion 105, which is a curved pipe, faces the internal opening end of the straight tubular portion 103, it is necessary to perform accurate axial alignment of the two and set an appropriate interval. there were. If the axis alignment is not accurate, extra flow resistance will occur, resulting in a large pressure loss. Further, even if the distance between the openings is large, the same problem occurs. On the contrary, if the space is too small, there is a problem that a sufficient silencing effect cannot be exerted.

Therefore, the present invention has the advantages of an injection-molded product that allows the shapes of the expansion chamber and the resonator chamber to be easily defined in accordance with the engine space, and at the time of assembling work, adjustment of the gap between the openings in the expansion chamber and axial alignment. It is an object of the present invention to provide a silencer that does not require the work of (1) and has a small number of parts and that is easy to assemble and work.

[0006]

In order to solve the above-mentioned problems, a muffler of the present invention comprises a case portion having a partition wall which divides an expansion chamber and a resonator chamber and partitions the expansion chamber and the resonator chamber. A first cylinder portion integrally molded with the case portion and having one end opening that opens to the expansion chamber and the other end opening that opens to the outside; and a first cylinder portion integrally molded with the case portion and exposed to the resonator chamber. A first wall portion having a resonator opening in the wall portion and having a one-end opening facing the expansion chamber and a one-end opening opening to the expansion chamber and the other end opening opening to the outside; It is characterized by comprising a case main body having two cylindrical portions and a lid body fixed to the case main body and forming the expansion chamber and the resonator chamber.

[0007]

In the muffler of the present invention, the first tubular portion and the second tubular portion that face each other and form the opening in the expansion chamber are integrally molded as a part of the case body. Therefore, it is possible to assure the precise formation of the opening, while the assembly work does not require the work of adjusting the space between the openings in the expansion chamber and adjusting the axis. Further, since there are only two components, the case body and the lid, it is not necessary to assemble the opposing pipes forming the opening, and the assembling work can be simplified to the utmost. At the same time, there is an advantage that a failure due to breakage of the joint portion of the component is extremely unlikely to occur.

As a result, according to the present invention, it is possible to provide, at a very low cost, a robust silencer having an expansion chamber and a resonator chamber, having a small flow path resistance and exhibiting stable and high silencing performance. become. Here, in the manufacture of the silencer of the present invention, the number of assembling steps has been reduced to the utmost limit, so that the effect of cost reduction is remarkably exhibited especially in mass production.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a silencer according to an embodiment of the present invention.
It will be described based on As shown in FIG. 1, the silencer of the present embodiment includes case portions 13 and 14 having partition walls 15 that partition the expansion chamber A and the resonator chamber B and partition the expansion chamber A and the resonator chamber B, and A first tubular portion 11 integrally molded with the case portions 13 and 14 and having one end opening 11a opening to the expansion chamber A and the other end opening 11b opening to the outside;
The wall portion that is integrally molded with the case portions 13 and 14 and that is exposed in the resonator chamber B has a resonator port 16, and is opposed to the one end opening 11a of the first tubular portion 11 with a gap and A case body 1 having a second tubular portion 12 having one end opening 12a opening to the expansion chamber A and another end opening 12b opening to the outside, and the expansion chamber A and the resonator chamber B fixed to the case body 1 And the lid body 2 to be formed.

That is, the silencer of this embodiment is composed of only two components, the case body 1 and the lid 2. The case main body 1 is mainly composed of the first cylindrical portion 11 facing each other.
The second tubular portion 12 and the case portions 13 and 14 arranged on both sides of the second tubular portion 12 are integrally molded. The first tubular portion 11 and the second tubular portion 12 are straight tubular members having a circular cross section, are arranged coaxially at intervals, and are opened to the expansion chamber A between the one end openings 11a and 12a facing each other. To form an opening. On the other hand, the first tubular portion 11 and the second tubular portion
The other end openings 11b and 12b of the cylindrical portion 12 which are opposed to each other are
At the peripheral edge of the opening end forming these, there is an engaging projection to be coupled with the intake system, and the opening is open to the outside. And
The second tubular portion 12 has a tubular resonator port 16 that opens downward in a tubular wall portion between the one end opening 12a and the side walls of the case portions 13 and 14 on the other end opening 12b side.

The case portions 13 and 14 arranged on both side surfaces of the first and second cylindrical portions 11 and 12 are shaped like a bowl with a downward opening. The internal space is partitioned by a partition wall 15 provided between the one end opening 12a of the second tubular portion 12 and the resonator port 16, and the expansion chamber A is provided on the first tubular portion 11 side and the second tubular portion is provided. A resonator chamber B is formed on the side of the resonator port 16 of 12.

As shown in FIG. 2, inward and outer walls 13w and 14w of the case parts 13 and 14 stand up from both side surfaces of the first and second cylinder parts 11 and 12, respectively. The inward and outward walls 13w and 14w are formed by the first tubular portion 11 and the second tubular portion 12, respectively.
It is continuous with the lower inner wall that also serves as the cylinder wall of the lower half. On the opposite side, the inward and outer walls 13w and 14w are continuous with the outer walls forming the ceiling and side surfaces of the case portions 13 and 14, and continue to the joint edge of the case body 1 with the lid 2.
Further, the case portions 13 and 14 each have an outer wall that is in vertical contact with the outer peripheral surface of the intermediate portion of the first tubular portion 11 on one side surface, and the outer peripheral surface of the intermediate portion of the second tubular portion 12 on the other side surface as well. Has an outer wall that is in vertical contact with and forms an inner space.

On the other hand, as shown in FIGS. 1 and 2, the lid 2 is a flat rectangular container having a substantially rectangular parallelepiped internal space. This internal space is divided into the expansion chamber A side and the resonator chamber B side by the partition wall 25 that comes into contact with the partition wall 15 of the case body 1 described above. The case body 1 and the lid body 2 are members made of synthetic resin and integrally molded. Both are the respective joint edges 1c,
2c are brought into contact with each other and welded together to be integrally assembled to form a muffler including the expansion chamber and the resonator chamber of this embodiment.

By the way, in order to integrally mold the case body 1 with a synthetic resin, the case body 1 can be integrally manufactured by using, for example, a mold shown in FIG. This figure is an end view showing a mold forming a vertical cross section taken along the axial center of both cylindrical portions 11 and 12 of the case body 1. That is, an upper mold C3 having a concave portion for molding the upper surface side of the case body 1 and a lower mold C4 having a convex portion for molding the lower surface side of the case body 1 are brought into contact with each other, and from both ends thereof. Then, the cylindrical insertion molds C1 and C2 forming the inner peripheral surfaces of the first cylinder part 11 and the second cylinder part 12, respectively, are coaxially inserted and mold molding is performed. The insert molds C1 and C2 have their end faces facing each other, and the convex parts C of the lower mold C4 for molding the case connecting part 10 are formed.
The one end openings 11 a and 12 a opening into the expansion chamber A are molded so as to be in close contact with the side surface of 40.

In this way, the first cylinder portion 11 and the second cylinder portion 12 which are coaxially opposed to each other, and the case portions 12 and 1 in which the expansion chamber A and the resonator chamber B are formed in the internal space.
It is possible to manufacture the case main body 1 in which 3 and the case connecting portion 10 that connects them are integrally molded. As described above in detail, in the silencer of the present embodiment, the first tubular portion 11 and the second tubular portion 12 that face each other and form the opening in the expansion chamber A are integrated as a part of the case body 1. It is molded into. Therefore, the assembly work does not require the work of adjusting the space between the openings in the expansion chamber A and the axis alignment work, but ensures the precise formation of the openings. Also,
Since there are only two components, that is, the case body 1 and the lid body 2, it is not necessary to assemble the opposing pipes forming the openings, and the assembly work is simplified to the utmost limit. At the same time, since the joints are only the welded portions of the joint edges 1c and 2c of the both, there is an advantage that there is very little possibility of failure due to destruction of the joints of the constituent elements.

As a result, the silencer of this embodiment has the expansion chamber and the resonator chamber, has a small flow path resistance, and exhibits stable and high silencing performance. It is also extremely robust and inexpensive. In particular, the number of assembling steps has been reduced to the utmost, so that the effect of cost reduction is remarkably exhibited in mass production. In the muffler of the present invention, as shown in FIG. 2 again, the inward and outer walls 13w and 14w rising from the side surfaces of the first tubular portion 11 and the second tubular portion 12 are such that the former is perpendicular to the side surfaces of both tubular portions. The latter is formed tangentially to the side surfaces of both tubular portions. The former 13w exemplifies a mold that emphasizes the ease of working of the upper mold C3 at the time of molding, and the latter 14w has a volume of the expansion chamber A formed in the case portion 14 as large as possible for a sound deadening effect. This is an example of a die that is emphasized. Therefore, at the time of implementation, the inward and outward walls 13w, 14w
It is desirable to unify one of these shapes.

Further, if the opening formed by the first and second cylinders 11 and 12 facing each other in the case connecting portion 10 is opened at an angle of more than half of the entire circumference, the silencing effect is effectively exhibited. To be done. Therefore, it is possible to reduce the height of the case connecting portion 10 for the convenience of manufacturing and to configure the opening portion so that the opening portion is not opened all around. Further, the first tubular portion 11 and the second tubular portion 12 do not necessarily have to be formed in a straight tube shape, and even if they are formed of a bent tube having a constant curvature, they are integrally formed by molding as in the present embodiment. It can be molded into Similarly, the cross section of the flow path is not limited to the circular shape, and various cross sections such as an elliptical shape and a rectangular shape can be taken. It is also possible to taper the insert dies C1 and C2 somewhat to narrow the flow path.

In addition, the joining edges 1c and 2c do not necessarily have to be on a flat surface, but the joining edges 1c and 2c may be formed as needed.
It is also possible to form three-dimensionally.

[Brief description of drawings]

FIG. 1 is a perspective view of a silencer as an embodiment of the present invention.

FIG. 2 is a side view taken along the arrow II in FIG.

FIG. 3 is an end view of a mold for molding the III-III section in FIG.

FIG. 4 is a perspective view showing the configuration and assembly of a silencer according to the prior art.

[Explanation of symbols]

1: Case body 1c: Joining edge 10: Case contact portion 13, 14: Case portion 1
5: Partition wall 11: 1st cylinder part 11a: One end opening 11b: Other end opening 12: 2nd cylinder part 12a: One end opening 12b: Other end opening 16: Resonator mouth 2: Lid 25: Partition wall 2c: Joining edge A: Expansion room B: Resonator room

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidetoshi Ishihara, No. 1 Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture Within Toyoda Gosei Co., Ltd. Address within Toyoda Gosei Co., Ltd.

Claims (1)

[Claims] 1. A case part having a partition wall that divides the expansion chamber and the resonator chamber and partitions the expansion chamber and the resonator chamber, and one end opening integrally formed in the case part and opening to the expansion chamber. A first tubular portion having the other end opening to the outside and a first tubular portion having a resonator port on a wall portion integrally molded with the case portion and exposed to the resonator chamber and opening to the expansion chamber A case body having a second tubular portion facing the one end opening with a gap and having one end opening that opens to the expansion chamber and the other end opening that opens to the outside; and the expansion fixed to the case main body. A silencer comprising: a chamber and a lid forming the resonator chamber.