JPS58101215A - Engine exhaust muffler - Google Patents

Abstract

PURPOSE:To require no press work, etc. and to improve the productivity of a muffler by forming a cavity in a block-like non-metallic inorganic material so as to introduce the exhaust gas into this cavity and to damp exhaust sounds. CONSTITUTION:A block body 26 is produced in one body with concrete as a non-metallic inorganic material. A suction chamber, first expansion chamber 30, resonance chamber 32, and second expansion chamber 34 are formed in the block body 26 and a crank case 36 is formed above individual chambers 28-34. Light-weight foaming concrete layers 37, 38 are formed inside the first and second expansion chambers 30, 34. The exhaust gas enters into the first expansion chamber 30 and expands, then enters into the second expansion chamber and expands again, thus damping exhaust sounds.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine exhaust muffler using a non-metallic inorganic material such as concrete.

Generally, in a heat engine (hereinafter referred to as an engine), high-temperature exhaust gas is guided to an exhaust muffler to attenuate exhaust noise, and then discharged into the atmosphere. Conventional engines usually use metal exhaust silencers, but this has the problem of requiring a large number of man-hours such as pressing and welding metal plates. In addition, since the metal plate used as the material generally has poor sound insulation and vibration absorption properties, it may be necessary to fill the interior with glass wool or the like, which has the disadvantage of further deteriorating productivity and increasing manufacturing costs.

Jin's invention was made in view of these circumstances,
It is an object of the present invention to provide an engine exhaust purifier that significantly improves productivity and also has an excellent exhaust sound muffling effect.

In order to achieve such an object, the present invention is configured such that a cavity is formed from a block-shaped non-metallic inorganic material, and exhaust gas is guided into the cavity to attenuate the exhaust noise. The present invention will be described in detail below based on the illustrated embodiments.

The drawings show an embodiment in which the present invention is applied to a portable engine generator. Fig. 1 is a front view thereof, Fig. 2 is a right side view, Fig. 3 is a sectional view taken along the layer-1 line in Fig. 1, and Fig. Figure 4 is a front view of the block body in which the crankcase, exhaust muffler, intake chamber, etc. are integrally formed, Figure 5 is a sectional view taken along the line v-■ in Figure 1, and Figure 6゜7.8 is Figure 4. FIG. 49 is a cross-sectional view taken along the line IX--IX in FIG. 8.

In Fig. 1.2.3, the reference numeral 10 denotes a two-stroke single cylinder engine, 12 a generator driven by this engine 10, and 14 a recoil type starter (Fig. 2).

The recoil type starter 14 is provided with a blower fan 16 as shown in FIG. Cooling. Generator 12 is engine 1o
1.2, and its front end has two legs 2° (20a, 20a) extending downward as shown in Figure 1.2.
0b) is fixed.

In FIGS. 1 to 3, 22 is an instrument panel, and 24 is a fuel tank. This fuel tank 24 contains a mixed oil consisting of gasoline and lubricating oil.

26 is a block body, and this block body 26 is integrally made of concrete as a non-metallic inorganic material. The block body 26 has intake chambers 2 in sequence from the right side in Fig. 4.
8, a first expansion chamber 30, a resonance chamber 32, and a second expansion chamber 34 are formed, and above each of these chambers 28 to 34 is a crank chamber 3.
6 is formed. All of these chambers 28 to 36 are open to the front side. Note that the first thing. A lightweight foamed concrete (hereinafter referred to as ALC) layer 37 is provided on the inner surface of the second expansion chamber 30.34.
, 38 are formed. That is, the ALC layers 37 and 38 are formed by making a box from ALC in advance and casting this ALC box when manufacturing the block body 26. (:(7) The ALC layers 37 and 38 have the effect of increasing sound absorption. 39.40 is between the intake chamber 28 and the [expansion chamber 30] and the lth layer.

These are air passages formed between the second expansion chamber 30, 34 and the crank chamber 36, respectively. These air passages 39 and 40 penetrate the block body 26 in the front-rear direction and form a heat insulating air layer.

The intake chamber 28 is connected to an intake pipe 42 that protrudes to the right as shown in FIG. 44
is attached, and a cover plate 46 is attached from the front. This cover plate 46 has an air intake hole 48 opened therein.

s41. In the second expansion, 1Q30.34, a lid material 50 made of a concrete block is attached to the resonance chamber 32 from the front. As is clear from FIG. 1.2.6.7.8, an exhaust pipe 52 protruding to the left is embedded in this lid member 50, and the right end of this exhaust pipe 52 communicates with the first expansion chamber 30. (Figure 6). 54, 56・ke・block body 2
6 and the base surface of the lid member 50, and the exhaust passage 54 is the exhaust passage formed between the first. The second expansion chamber 30.34 is communicated with the exhaust passage 56, and the exhaust passage 56 communicates with the resonance chamber 32 (FIG. 4.6.7). As described above, in this embodiment, there are a plurality of cavities between the concrete block body 26 and the cover material 50, that is, the first cavity. Second expansion chamber 30°3
4 and a resonance chamber 32 are formed, and these constitute an exhaust muffler.

In Figure 4.8.9, 58.60 is block body 2
The rear end of the exhaust passage 58 is connected to the second expansion chamber 34 through a pipe 62, and the rear end of the exhaust passage 60 is open to the back surface of the block body 26. The front ends of both of these exhaust passages 58 and 60 communicate with each other through a passage 64 formed between the base surfaces of the block body 26 and the cover member 50. As a result, the exhaust from the engine 10 is transmitted through the exhaust pipe 52,
1st and 2nd expansion chambers 30.34. It is discharged to the rear of the block body 26 through exhaust passages 58,60.

Next, the engine IO will be explained. As is clear from FIG. 6, the crank chamber 36 formed in the block body 26 has a wide opening at the front, and the inner peripheral surface 66 of the crank chamber 36 on the opening side is slightly tapered toward the front. The diameter is expanding. Further, a metal substantially cylindrical boss 68 is integrally embedded in this block body 26, and this boss 68 supports a crankshaft 70, which will be described later.

In FIG. 3, 70 is a crankshaft, and 72 is a connecting rod. These assemblies are installed into the crank chamber 36 through the opening of the crank chamber 36, and the rear part of the crankshaft 79 is supported by the boss 68 by a bearing 74. do. 76 is a crankcase lid material made of concrete block,
A metal substantially cylindrical boss 78 is integrally embedded in the center thereof. This cover member 76 is attached to the opening of the crank chamber 36 from the front side of the block body 26, and at this time, the crankshaft 7
0 is supported on the boss 78 by a bearing 8o.

82 is a piston attached to the upper end of the connecting rod 72;
84 is a cylinder body, 86 is a cylinder head,
The cylinder body 84 and cylinder head 86 are fixed to the block body 26 by bolts 88 (see FIG. 4) installed in the block body 26. In FIG. 3, 90 is a scavenging passage, and 92 is a spark plug.

Note that the cover material 76 attached to the crank chamber 36 of the block body 26 and the base surface 94 of the block body 26 are connected to the cylinder body 84 and the block body 26 as shown in FIG.
and the base surfaces 94 .
96 do not intersect with each other. In other words, since the dimensional accuracy of non-metallic inorganic materials such as concrete is generally poorer than that of metallic materials, these two base surfaces 94
, 96 intersect (in the second case, there is a risk that the sealing performance will deteriorate. In this embodiment, these base surfaces 94 and 96 are joined via a gasket so that they do not intersect with each other, so that the sealing can be performed reliably. .

In FIG. 1.3, 100 is a carburetor, and this carburetor 100 is installed in the block body 26.
2 (FIG. 4), it is attached to the block body 26 via the reed valve 104. Further, 104 is a duct connecting the intake pipe 42 and the carburetor 100. In FIG.
This is the exhaust pipe that leads to 2.

Next, the operation of this embodiment will be explained. First, turn on the main switch of the engine 10 and turn on the recoil starter 14.
Manually start engine lo. Intake air passes through the intake hole 48 , filter 44 , intake chamber 28 , intake pipe 42 , duct 106 , carburetor 100 , reed valve 104 , and enters the piston 82 .

As it rises, it is sucked into the crank chamber 36. vaporizer 1
The air-fuel mixture consisting of the fuel mixed at 00 and the intake air is pre-pressurized within the crank chamber 36 as the piston 82 descends, and then enters the combustion chamber through the scavenging passage 90 and is combusted.

The exhaust of the engine 10 passes through the exhaust pipe 108.52 to the first
It enters the expansion chamber 30 and expands here. The exhaust gas is then throttled through the exhaust passage 54, enters the second expansion chamber 34, and expands again. That is, the exhaust gas interferes with each other while expanding within these expansion chambers 30, 34, and the exhaust noise is attenuated. Meanwhile, the resonance chamber 32 absorbs the vibration energy of the exhaust gas. As a result, the exhaust noise is sufficiently attenuated by the exhaust silencer formed by the expansion chambers 30, 34, resonance chamber 32, etc., and the exhaust is then
It is discharged through air passages 58,60. Further, since the block body 26 is made of concrete which has excellent sound insulation and vibration absorption properties as well as sound absorption properties, the exhaust noise silencing effect is further improved.

In this embodiment, since the ALC layer is formed on the inner surface of the expansion chamber 30, 34, the exhaust sound can be further attenuated due to the high sound absorbing property of the ALC layer itself. Furthermore, since the air passages 39 and 40 are formed in the block body 26, the heat of the exhaust gas is extremely difficult to be transmitted to the intake chamber 28 and the crank chamber 36. Therefore, the intake chamber 28 and the crank chamber 36 do not become overheated, and problems such as performance deterioration due to heat do not occur.

In the above examples, concrete is used as a non-metallic inorganic material.
'1. /) Therefore, not only is it easy to manufacture by simply pouring concrete into a mold and hardening it, but the materials are also inexpensive. However, it goes without saying that this invention may use materials other than concrete, such as ceramics.

As described above, this invention forms a cavity in a block-shaped non-metallic inorganic material and attenuates exhaust noise with this cavity, so processing such as pressing and welding required for a metal exhaust silencer is not required. It becomes unnecessary, and the productivity of the silencer is significantly improved. In addition, non-metallic inorganic materials have excellent sound insulation and vibration absorption properties, and if materials such as concrete, which are particularly excellent in sound absorption properties, are used, the sound damping effect will be even better. This eliminates the need for filling with glass wool, which is often used in metal silencers, and the effects of improving productivity and reducing manufacturing costs are even more significant.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an embodiment of the present invention, Fig. 2 is a right side view, Fig. 3 is a sectional view taken along the line m-m in Fig. 1, and Fig. 4 is a front view of the main body of the pro. , FIG. 5 is a sectional view taken along the line V-V in FIG. 1, and FIG. 7.8 is a cross-sectional view taken along line MV, ■-■, and ■-■ in FIG. 4, and FIG. 9 is a cross-sectional view taken along line IX--X in FIG. 10... Engine, 26... Block body, 30.
...First expansion chamber as a cavity, 32... Resonance chamber as a cavity, 34... Second expansion chamber as a cavity, 50... Lid material. Patent Applicant Yamaha Motor Co., Ltd. Agent Patent Attorney Yama 1) Written by Yuhe 6 Figures 5 Figure 7 Figure 7 % 6 Procedural Amendment Letter March 10, 1981 Commissioner of the Japan Patent Office Island 1) Spring Aidan 1, Display of the case - Relationship with the case of Patent Application No. 199040 of 1981 The number of inventions increases due to the patent applicant 6Flli 07, the specification and drawings to be amended '8, the content of the amendment as shown in the attached sheet. 8. Contents of the amendment U) On page 4, line 3 of the specification, the phrase "lightweight foamed concrete" is amended to read "lightweight foamed concrete, which is a type of lightweight porous material." (2) On the 8th line of the same page of the same book, the phrase ``r39.40 is'' has been amended as follows. "
Note that the layer may be formed of various lightweight porous materials instead of ALC. 39.40” (3) Ibid., page 7, No. 1
In line 7, "dimensional accuracy" is corrected to "surface accuracy." (4) Ibid., page 8, line 8, r104. Correct the text "J" to "II 06J". (5) Correct Figure 1 as marked in red on the attached sheet. (6) Section 3.6.8. Correct the figure as attached. Above Figure 3 TooA-1...-J Atsushi Figure 6

Claims (1)

[Claims] An engine exhaust muffler, characterized in that a cavity is formed in a block-shaped nonmetallic inorganic material, and exhaust noise is attenuated by guiding exhaust gas to the first cavity.