JPH04137210U - Sound absorbing silencer - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose of the present invention is to provide a sound-absorbing silencer that has a simple structure and prevents sound-absorbing material from scattering without increasing the number of parts. . [Structure] In a sound absorbing type muffler, a sound absorbing material 15 is installed between an exhaust pipe having a large number of small holes 3 and an outer cylinder 5 surrounding the exhaust pipe. A plurality of protrusions are provided on the circumferential wall of the exhaust pipe, avoiding the small holes 3, and a predetermined gap is secured between the exhaust pipe and the sound absorbing material 15 by the protrusions. Claim 2 provides that the protrusion is provided as a protrusion that protrudes along the longitudinal direction of the exhaust pipe or the circumferential direction of the exhaust pipe, and claim 3 provides that the protrusion is provided along the entire circumference of the exhaust pipe. The above protrusion is provided with a protrusion.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a sound absorbing muffler installed in a vehicle exhaust system.

0002

[Conventional technology]

Conventionally, vehicle exhaust systems have been equipped with a A silencer is installed, and the exhaust energy is expanded in the expansion chamber of the silencer. Exhaust noise is muffled by tension damping effect and resonance damping effect in the resonance chamber. In addition, there are high frequency regions that are difficult to muffle with the above-mentioned mufflers, so these days, many vehicles In addition to such a silencer, a silencer as shown in FIG. 6 is installed.

0003 Figure 6 shows how high-frequency components of exhaust energy are muffled using heat-resistant sound-absorbing materials. This shows a sound absorption type muffler. In the figure, 1 is the muffler pipe through which exhaust gas from the engine flows down. A large number of small holes 3 are bored in the peripheral wall of the muffler pipe 1, and the muffler pipe 1 is The hula pipe 1 is surrounded by an outer cylinder 5 and a chamber cap 7. The outer cylinder 5 is made of a pipe material with an inner diameter larger than that of the muffler pipe 1, and one end thereof is It is squeezed and welded and fixed to the outer periphery of the muffler pipe 1. And outer cylinder 5 and muff A cylindrical glass with a certain wall thickness is formed in the space formed between the pipe 1 and the pipe 1. A sound absorbing material 9 made of wool is inserted into the opening at the other end of the outer cylinder 5. It has a structure in which a bar cap 7 is attached.

0004 Therefore, the exhaust energy of the high frequency component of the exhaust noise emitted from the engine is - will be absorbed by the sound absorbing material 9. However, in the above-mentioned sound absorbing type muffler, between the outer periphery of the muffler pipe 1 and the sound absorbing material 9 Since there is no gap, the exhaust gas flow constantly flowing down the muffler pipe 1 directly hits the sound absorbing material 9. The sound absorbing material 9 is caused by the vortex generated in each small hole 3 due to the pulsation of the exhaust gas. There was a risk that the particles would be scattered outside through the small holes 3 and the muffler pipe 1.

[0005] Furthermore, Japanese Utility Model Application Publication No. 58-183923 discloses that a sound absorbing material made of glass wool is used as a masking material. Sound absorbing material and muffler formed by filling a predetermined distance from the hula pipe Fill the annular area between the pipe with metal wool, or alternatively, fill the annular area with a large number of small A sound-absorbing silencer made of a partition pipe with holes drilled in it to prevent the sound-absorbing material from scattering has been opened. It is shown.

[0006] Similarly, Japanese Utility Model Application Publication No. 58-169104 discloses that exhaust gas located in a sound absorption chamber is A buffer member with a wave-shaped pipe wall in the longitudinal direction between the outer peripheral surface of the pipe and the sound absorbing material. Disclosed is a technology that prevents sound-absorbing material from scattering from small holes in exhaust gas pipes by installing It is.

[0007]

[Problem that the idea aims to solve]

However, in the conventional example disclosed in the above-mentioned Japanese Utility Model Application Publication No. 58-183923, In order to prevent the sound absorbing material from scattering, place metal wool between the sound absorbing material and the muffler pipe. Since the structure requires filling and forming an annular area with a partition pipe, there are many parts and costs are high. There was a drawback that it took a while.

[0008] Similarly, in the latter conventional example disclosed in Utility Model Application Publication No. 58-169104, In addition, the number of parts is large and the structure is difficult to install because the buffer member has a corrugated pipe wall. It has been pointed out that the drawback is that it is structurally complex. The present invention was devised in view of such circumstances, and it is possible to simplify the process without increasing the number of parts. The purpose is to provide a sound-absorbing muffler that prevents sound-absorbing material from scattering with a simple structure. .

[0009]

[Means to solve the problem]

In order to achieve this object, the device according to claim 1 provides an exhaust system with a large number of small holes. In a sound-absorbing silencer in which a sound-absorbing material is attached between the trachea and the outer cylinder surrounding it. , a plurality of protrusions are provided on the peripheral wall of the exhaust pipe surrounded by the outer cylinder, avoiding the small holes, and The protrusion ensures a predetermined gap between the exhaust pipe and the sound absorbing material.

0010 In the invention according to claim 2, the protrusion is arranged in the longitudinal direction of the exhaust pipe or in the longitudinal direction of the exhaust pipe. The device is formed of protrusions extending along the circumferential direction, and the device according to claim 3 The above-mentioned protrusion is formed by a protrusion that protrudes around the entire circumference of the exhaust pipe.

[0011]

[Effect]

According to the invention described in claim 1, the exhaust gas released from the engine is inside the exhaust pipe. As with the conventional system, the pulsation of exhaust gas creates a vortex in the small hole in the exhaust pipe. Although a flow occurs, the protrusion ensures a distance between the small hole and the sound absorbing material so that the exhaust gas flow reaches the sound absorbing material. In addition to preventing direct contact, the vortex generated in each small hole affects the sound absorbing material. This reduces the noise and prevents the sound absorbing material from scattering.

0012 In the invention of claim 2, the exhaust pipe is provided in the longitudinal direction of the exhaust pipe or in the circumferential direction of the exhaust pipe. In the invention of claim 3, the protrusion protrudes along the entire circumference of the exhaust pipe. The protrusions ensure a distance between the small hole and the sound absorbing material so that the exhaust gas flow directly hits the sound absorbing material. At the same time, it reduces the influence of the vortex generated in each small hole on the sound-absorbing material. Prevents sound materials from scattering.

[0013]

【Example】

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In addition, the conventional example shown in FIG. Components that are the same as those shown in FIG. 1 and 2 show a first embodiment of a sound absorbing muffler according to the present invention. 1 is a muffler pipe surrounded by an outer cylinder 5 and a chamber cap 7, as shown in FIG. Similar to the conventional example shown in , a plurality of small holes 3 are bored in the peripheral wall.

[0014] The outer cylinder 5 and the chamber cap 7 are mounted on the peripheral wall of the muffler pipe 11. As shown in Fig. 2, except for the two end portions where the 3 in the longitudinal direction over almost the entire length of the muffler pipe 11 with an interval of 90°. It is installed protrudingly. Then, a sound absorbing material 15 made of glass wool formed into a cylindrical shape is installed. When inserted into the space between the muffler pipe 11 and the outer cylinder 5, these protrusions 13 Thus, a predetermined gap 17 is secured between the muffler pipe 11 and the sound absorbing material 15. It has become.

[0015] However, each of the protrusions 13 is provided avoiding the small hole 3, and all the protrusions 13 are provided with It has a structure in which not a single small hole 3 is bored. Therefore, each protrusion 13 As a result, a predetermined gap 17 is secured between the muffler pipe 11 and the sound absorbing material 15. The sound absorbing material 15 is prevented from being directly exposed inside the muffler pipe 11 from each small hole 3. ing.

[0016] Since this embodiment is configured in this way, the amount of water emitted from the engine is reduced as in the conventional case. The exhaust energy in the high frequency range is muffled by the sound absorbing function of the sound absorbing material 15. It will be done. In addition, the exhaust gas released from the engine constantly flows down inside the muffler pipe 11, and As in the conventional case, vortices are generated in each of the three small holes due to the pulsation of exhaust gas, but each of the above-mentioned protrusions 13 ensures a distance between the small hole 3 and the sound absorbing material 15 so that the exhaust gas flow directly hits the sound absorbing material 15. In addition to preventing dripping, the influence of the vortex generated in the three small holes on the sound absorbing material 15 This reduces the noise and prevents the sound absorbing material 15 from scattering due to exhaust gas.

[0017] Therefore, according to this embodiment, the above-mentioned Japanese Utility Model Application Publication No. 58-183923 and Compared to the conventional example shown in Publication No. 58-169104, it is simpler without increasing the number of parts. It was possible to prevent the sound absorbing material from scattering with a simple structure. In addition, for example, in the conventional example shown in FIG. When inserting the sound absorbing material 9 and the muffler pipe 1 between the However, in this embodiment, only the tips of the four protrusions 13 are covered with the sound absorbing material 1 when inserted. 5, so compared to the conventional example, the above-mentioned Utility Model Application Publication No. 58-18 Compared to the conventional examples disclosed in Publication No. 3923 and Publication of Utility Model Application No. 169104/1983. This has the advantage that the sound absorbing material 15 can be easily inserted and productivity can be improved.

[0018] In addition, in the first embodiment, the parts other than the joints with the outer cylinder 5 and the chamber cap 7 are Although four protrusions 13 are provided to protrude in the longitudinal direction of the hula pipe 11 over substantially the entire length thereof. , as shown in FIG. 3, a muffler pipe 19 with a plurality of small holes 3 is formed in the longitudinal direction. Along the entire circumference of the muffler pipe 19, a bead-shaped protrusion 21 shorter than the protrusion 13 is attached. A plurality of protrusions are provided on the muffler pipe 19 and the sound absorbing material 1 by these protrusions 21. 5, a gap 23 may be provided between the two. Also, although not shown, the circumference of the muffler pipe Multiple bead-shaped protrusions are provided in the direction, and these protrusions connect the muffler pipe and the sound absorbing material. A gap may be provided in between. Note that, as in the first embodiment above, there are Even if the sound absorbing material 15 is not exposed directly into the muffler pipe 19 from the small hole 3, The protrusion 21 is provided avoiding the small hole 3.

[0019] Therefore, these examples also achieve the intended purpose as in the first example above. It is possible to accomplish this. Further, FIG. 4 shows a third embodiment of the present invention, in which the above-mentioned protrusions 13 and 21 are replaced with In addition, a plurality of small holes 3 are drilled around the entire circumference of the muffler pipe 25, avoiding the small holes 3. The muffler pipe 25 is provided with several protrusions 27, and these protrusions 27 A gap 29 is secured between the sound absorbing material 15 and the sound absorbing material 15.

[0020] In this embodiment, each of the projections 27 ensures a distance between the small hole 3 and the sound absorbing material 15. This prevents the exhaust gas flow from directly hitting the sound absorbing material 15, and also prevents the exhaust gas from hitting the sound absorbing material 15 directly. The effect of the generated vortex on the sound absorbing material 15 is reduced, and the sound absorbing material 15 is reduced by the exhaust gas. Prevent scattering. Therefore, like the above embodiments, this embodiment also reduces the number of parts compared to the conventional example. It was possible to prevent the sound absorbing material from scattering with a simple structure without increasing the number of parts.

[0021] In each of the above embodiments, the muffler pipe is surrounded by an outer cylinder and a chamber cap, A structure in which a cylindrical sound-absorbing material is inserted between the outer cylinder and the muffler pipe. The present invention is applied to a sound absorption type muffler, as shown in Fig. 5. The muffler pipe 35 is surrounded by an outer cylinder 33 having a reduced diameter portion 31, and the outer cylinder 3 3 and the muffler pipe 35 is a sound absorbing material 3 made of glass wool formed into a cotton shape. It can also be applied to a sound absorbing type muffler having a structure in which 7 is filled.

[0022] That is, as shown in the figure, the muffler pipe 35 surrounded by the outer cylinder 33 is As in the first embodiment, four bead-shaped protrusions 39 are provided protrudingly, and one diameter is reduced. After welding the section 31 to the muffler pipe 35, a A wire mesh 41 formed in a cylindrical shape is inserted into the space formed along each protrusion 39, and , a sound absorbing material 37 is filled between the wire mesh 41 and the outer cylinder 33, and the other side of the outer cylinder 33 is squeezed. Then, the reduced diameter portion 31 may be welded to the muffler pipe 35.

[0023] According to this structure, the wire mesh 41 disposed on the inner circumference of the sound absorbing material 37 and the muff Since a gap 43 is formed between the lap pipe 35 by the protrusion 39, such a structure As with each of the above embodiments, it is possible to achieve the intended purpose with the sound absorbing muffler. It is possible.

[0024]

[Effect of the idea]

As stated above, according to the invention described in each claim, it is possible to process the exhaust pipe. Therefore, it is possible to prevent the sound absorbing material from scattering, and therefore, the number of parts can be increased compared to the conventional example. It was possible to prevent the sound absorbing material from scattering with a simple structure.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a sound absorbing muffler according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG. 1.

FIG. 3 is a sectional view of a sound absorbing muffler according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a sound absorbing muffler according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a sound absorbing muffler according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a conventional sound absorbing muffler.

[Explanation of symbols]

5,33 Outer cylinder 7 Chamber cap 11, 19, 25, 35 Muffler pipe 13, 21, 39 protrusions 15,37 Sound absorbing material 17, 23, 29, 43 Gap 27 Protrusion

Claims (3)

[Scope of utility model registration request] [Claim 1] An exhaust pipe having a large number of small holes (3),
A sound absorbing material (1
5, 37), a plurality of protrusions are protruded from the peripheral wall of the exhaust pipe surrounded by the outer cylinder (5, 33), avoiding the small hole (3). , a predetermined gap (17, 37) is formed between the exhaust pipe and the sound absorbing material (15, 37) at the protrusion.
23, 29, 43). 2. The sound absorbing type according to claim 1, wherein the protrusion is a protrusion (13, 21, 39) that protrudes along the longitudinal direction of the exhaust pipe or the circumferential direction of the exhaust pipe. Silencer. 3. The sound absorbing muffler according to claim 1, wherein the protrusion is a protrusion (27) that protrudes around the entire circumference of the exhaust pipe.