JPH073011Y2 - Muffler for supercharger for internal combustion engine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silencer for a supercharger using an exhaust gas turbine that converts the energy of exhaust gas from an internal combustion engine into mechanical work.

2. Description of the Related Art FIG. 2 and FIG. 3 are cross-sectional views showing two examples of conventional representative internal combustion engine superchargers. In each figure, the compressor impeller 01 and the front blades 02 are driven by an exhaust gas turbine 03. The muffler 04 reduces noise generated by the rotation of the impeller 01 and the front blades 02 during air compression.

In both the silencer 04 of FIGS. 2 and 3, an opening 06 for sucking air is provided on the outer peripheral side with respect to the axis 05 of the supercharger, so that the inflow direction of the sucked air is different in each figure. It is in the radial direction as shown by the large arrow 07.

The muffler 04 has a sound absorbing segment 08 for muffling, and due to the passage length here, the air passage area 09 inside the muffler is surprisingly small. For this reason, the silencer has a relatively large structure (dimensions) with respect to the main body of the supercharger in order to reduce air suction loss.

Also, after air flows in the radial direction of arrow 07, arrow 010
Since the direction is changed to the axial direction of, the suction pressure loss tends to increase due to bending loss, merging loss, and the like.

Unlike Fig. 2 and Fig. 3, Fig. 4 shows the air passage with arrow 07,0.
Although it is a type having a vented cross-sectional shape as shown in 10, the air suction surface is provided on the outer periphery of the supercharger. The description of other symbols is the same as that of FIG.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As described above, in the conventional turbocharger for an internal combustion engine, since it is located on the outer periphery of the axis of the muffler and the air suction direction is bent at a right angle, air bending loss and merging loss occur. Therefore, there is a problem that the suction pressure loss becomes large, and the suction area becomes insufficient so that the air suction pressure loss becomes large.

In addition, the size of the silencer cannot be made larger than that of the supercharger, so there is a limit to the volume of silencer, and since the structure is complicated, there are few common parts, and there are many types of parts, making mass production difficult and costly. There was a problem that was high.

The present invention has been made to solve the problems of the prior art, and can reduce the pressure loss of air and increase the volume of sound with a short length to reduce the size and weight, and to reduce the common parts. An object of the present invention is to provide a silencer for an internal combustion engine supercharger.

Means for Solving the Problems In order to solve the above problems, the present invention provides a silencer for a turbocharger for an internal combustion engine, in which a circular or polygonal air suction port is provided in the front of the turbocharger, and an air suction direction is provided. Is provided in the same direction as the axis of the supercharger, and a plurality of sound absorbing materials are provided in parallel with the axis of the supercharger and at a predetermined interval between the sound absorbing materials over the entire air suction port, The passage areas of the front surface and the rear surface of the sound absorbing material are configured to be substantially the same.

Action According to the above means, the air is sucked in from the front of the supercharger and smoothly flows rearward along the axis of the supercharger without changing the direction, so that the pressure loss can be reduced. In addition, by arranging a plurality of sound absorbing materials in parallel along the air flow to form a so-called sound absorbing splitter structure, the sound deadening volume of each sound absorbing material is increased to reduce the size and weight of the sound absorbing material, and to make common parts. be able to.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

FIG. 1 is a sectional view showing an embodiment of a muffler for a supercharger for an internal combustion engine according to the present invention, which is substantially the same as the front wing, impeller, exhaust gas turbine rotor, etc. of the supercharger for an internal combustion engine. Since it is the same as that shown in FIGS. 2 to 3, description thereof will be omitted.

Therefore, in the present invention, the muffler 1 provided in the front stage of the front wing is arranged with its air suction port facing the front of the supercharger, and the air suction direction is the same as the axis of the supercharger. That is, inside the circular or polygonal air suction port, a plurality of sound absorbing members 6 extend long in parallel to the axis 7 of the supercharger and with a predetermined space 3 between the sound absorbing members 6. Thus, it is arranged over the entire air suction port. Then, air flows from the front surface 4 to the rear surface 5 of the sound absorbing material 6 as indicated by the arrow 2 in the flow path interval 3 between the plurality of sound absorbing materials 6.

Therefore, the air passage areas formed by these flow path intervals 3 are substantially the same on the front surface 4 and the rear surface 5 of the sound absorbing material 6. The air passing through the muffler 1 is smoothly introduced to the rear front blade along the direction of the axis 7 of the supercharger without changing the direction. Therefore, in comparison of the areas inside and outside (the front surface and the rear surface) of the sound absorbing material, unlike the conventional ones shown in FIGS. 2, 3, and 4, there is no problem that the rear surface has a smaller area, and Even if the suction port is limited to only the front surface of the supercharger, there is no drawback that the suction area is insufficient and suction pressure loss increases. On the contrary, in contrast to the conventional suction pressure loss of FIG. 2 of 120 mmAq, the pressure loss of the present invention is as small as 90 mmAq.

Further, by arranging a plurality of sound absorbing materials 6 in parallel along the air flow to form a so-called sound absorbing splitter structure,
The volume of each sound absorbing material can be increased to reduce the size and weight of the sound absorbing material, and the parts can be shared.

That is, by arranging the intervals 3 between the parallel sound absorbing materials 6 so as to match the fundamental frequency of noise so that the advantages of the sound absorbing splitter structure can be fully exerted, a short length of, for example, 40 dB can be obtained.
(A) It is possible to obtain a silencer volume higher than the above, and as a result, it is possible to reduce the size and weight of the silencer as a whole.

Further, by adopting the sound absorbing splitter structure, the sound absorbing material 6
Can be standardized by simplifying and standardizing the number and changing the number of sheets according to the air volume, thereby enabling mass production and significant cost reduction.

It should be noted that, in the above description, the reason for muting around the fundamental frequency part is as follows. That is, the noise generated by the turbo compressor is 4000 to 60 which is the fundamental frequency.
00Hz is a sharp and outstanding frequency characteristic with a level of 130 to 140 dB (A). This noise must be reduced to 100 dB (A), which is similar to the engine side noise. Therefore, the muffling volume is 30 to 40 dB (A), and it is necessary to muffle the fundamental frequency part which is particularly annoying to maintenance personnel.

Also, the sound absorbing material of conventional silencers is mainly felt,
Although the scattering due to the air flow can be prevented without special protection of the surface, the sound absorption coefficient was low at 0.6 to 0.7 in the high frequency part, but in the present invention, the sound absorbing material is arranged in parallel along the air flow. Since it is a sound absorbing splitter structure, it is possible to improve the sound absorption coefficient to 0.9 to 1.0 by using a high density glass wool board as a sound absorbing material,
The protective material on the surface can be made lightweight by using a perforated plate made of aluminum.

As described above, according to the present invention, in the silencer of the turbocharger for an internal combustion engine, air is sucked in from the front of the turbocharger,
It smoothly flows rearward along the axis of the turbocharger without changing the direction, so pressure loss can be reduced and
By arranging multiple sound-absorbing materials in parallel along the air flow to form a so-called sound-absorbing splitter structure, the sound-deadening volume of each sound-absorbing material is increased to reduce the size and weight of the sound-absorbing material, and to share parts. This makes it possible to significantly reduce costs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing an embodiment of a silencer for a supercharger for an internal combustion engine according to the present invention, and FIGS. 2, 3, and 4 are for a conventional internal combustion engine. It is sectional drawing which shows three different examples of the silencer of a supercharger. 1 ... Silencer, 2 ... Air inflow direction, 3 ... Spacing of sound absorbing material, 4 ... Front of sound absorbing material, 5 ... Rear surface of sound absorbing material, 6 ...
Sound absorbing material, 7 ... axis.

Continued Front Page (72) Inventor Shigetoshi Shigeto 1-1 1-1 Atsunoura-machi, Nagasaki-shi, Nagasaki Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (56) References JP-A 51-120315 (JP, A) JP-A 50 -52443 (JP, A) Actually opened 54-69202 (JP, U) Actually opened 52-8705 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A circular or polygonal air suction port is provided in the front of the supercharger, the air suction direction is the same as the axis of the supercharger, and a plurality of sound absorbing materials are arranged in parallel with the axis of the supercharger. A supercharger for an internal combustion engine, characterized in that the passage areas of the front surface and the rear surface of the sound absorbing material are configured to be substantially the same, with a predetermined space between the sound absorbing materials being provided over the entire air suction port. Silencer.