JPS6246806Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to an exhaust system, and particularly to an exhaust system suitable for automobiles and the like equipped with multi-cylinder engines.

(Prior Art) In general, as shown in Fig. 1, in an exhaust system for an automobile or the like equipped with a multi-cylinder engine, an exhaust manifold 2 is provided to cover each exhaust port of an engine 1. The discharged exhaust gas is collected by this exhaust manifold 2, guided to one or two exhaust pipes 3, passed through a muffler 4, and discharged to the outside air from a tail tube 5.

(Problems to be solved by the invention) In such an exhaust system, the exhaust gas collection method and collection position, the thickness of the exhaust pipe 3, the expansion and contraction action of the exhaust gas in the muffler 4, etc. Significant power loss has occurred.

Further, the muffler 4 has a circular or elliptical cross section, has a cross-sectional area ten times that of the exhaust pipe 3, and has a considerable length in the axial direction.
In automobiles, etc., installation is subject to space constraints, and it is often difficult to install it in the optimal position for noise reduction.

Furthermore, the weight distribution of the entire exhaust system becomes uneven, and great consideration must be given to the installation of this system and the selection of cushioning materials for elastically supporting this system.

The present invention was made in order to solve the problems and drawbacks of the prior art described above, and it is an object of the present invention to provide an exhaust system that does not cause output loss of exhaust gas, is not limited by installation space, and is easy to install. With the goal.

[Structure of the invention] (Means for solving the problem) In order to achieve the above object, the present invention includes an upstream conduit through which exhaust gas discharged from a plurality of engine cylinders flows, and one end of this upstream conduit. It has a downstream conduit that communicates with the downstream conduit, and the outside of the downstream conduit is covered with a sound-absorbing cover, and a part of the exhaust gas is transferred to the downstream conduit within the muffling cover using a noise-muffling device provided between the muffling cover and the downstream conduit. In an exhaust device that functions as a muffler by opening a small hole leading into a space, the upstream conduit is an upstream conduit group consisting of a plurality of upstream conduits each independently connected to each exhaust port of the plurality of engine cylinders. On the other hand, the downstream conduit constitutes a downstream conduit group consisting of a plurality of downstream conduits connected in series corresponding to each of the plurality of upstream conduits, and this downstream conduit group is arranged on the same plane. It is formed by thin-walled tubes arranged in parallel in close proximity, and furthermore, the entire downstream conduit group from almost the starting end to the terminal end is covered by the sound deadening cover, and a plurality of spaces are formed by partitioning the inside of this sound deadening cover. The silencing space is defined as the silencing space, and the small holes of the downstream conduits communicating with the silencing space are commonly included in one silencing space.

(Function) By doing this, the diameter of each conduit can be made small, exhaust gas can be discharged straight with almost no resistance, there is no output loss, the exhaust noise is small, and furthermore, the pipe diameter of each conduit can be reduced. By distributing the load to the individual conduits, each conduit can be thinner and weigh less. In addition, the muffler has a flat shape below the conduit, and it is possible to freely install a muffler that exhibits the desired muffling performance in the optimal position, making it especially suitable for vehicles with flat floors. Become a vessel.

(Embodiments) Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 to 12.

FIG. 2 shows an exhaust system for a four-cylinder engine showing one embodiment of the present invention, and is a sectional view showing the entire structure from the exhaust port of the engine cylinder to the exhaust gas discharge end.

In FIG. 2, the exhaust system E includes a flange 10 attached to the exhaust port of the engine cylinder via a gasket (not shown), and an upstream conduit group 11b consisting of a plurality of upstream conduits 11a connected to the flange 10. , and a muffler 13 whose constituent element is a downstream conduit group 19b consisting of a plurality of downstream conduit pipes 19a connected to the upstream exhaust pipe group 11b via flexible tubes 12.

An end plate 14 is attached to the right end of the upstream conduit group 11b, and one flange 1 of a flexible tube 12 as shown in FIG.
5a is attached by bolts or welding. Further, a silencer 1 is attached to the other flange 15b.
3 end plates 16 are attached.

The flexible tube 12 is used to prevent vibrations from the engine from being transmitted and to provide flexibility in the mounting positional relationship between the upstream conduit group 11b and the muffler 13.
Attachment of 5a and 15b to the end plates 14 and 16 is as follows:
This is done by interposing a sealing material such as a gasket between the two members and tightening them with bolts.

The muffler 13 has downstream conduits 19a having the same number and diameter as the upstream conduits 11b and arranged in parallel and close to each other on the same plane, and each of the upstream conduits 11a
The main component is a group of downstream conduits 19b connected in series so as to correspond to the group of downstream conduits 19b, and the outside of the group of downstream conduits 19b is covered with a sound deadening cover 20, which will be described later.

The downstream conduit 19a is made of a thin-walled tube (hereinafter, the downstream conduit 19a will be referred to as a thin-walled tube 19a).

The thin tubes 19a may be provided at very small intervals as shown in FIGS. 4 to 6, or they may be provided in close contact with each other as shown in FIG.

In the one shown in FIG. 7, thin tubes 19a are arranged so as to be in contact with each other and covered with a sound deadening cover 20. As shown in FIG. 2, this muffling cover 20 is provided to cover the downstream conduit group 19b from its starting end to its terminal end.
The inside is partitioned off by a recess 20b provided in the sound deadening cover 20. And this recessed part 20
b supports each thin tube 19a and forms a silencing space S (see FIGS. 2 and 5).

As mentioned above, if the thin tubes 19a are brought into contact with each other, the muffler part becomes flat except for the part where the muffler space S is formed, and the muffler as a whole becomes compact, making it ideal for small-displacement engines. You can get something.

The pair of sound deadening covers 20 are joined to each other so that their middle skins are aligned, and the flange portions 20a formed at the joined portions are brought into contact with each other by seam welding or the like.

Further, the thin tube 19a existing in the silencing space S is provided with a small hole O for allowing a portion of the exhaust gas to flow out into the silencing space S at an appropriate predetermined position. Each of these thin tubes 19a
The positions of the small holes O are irregular in the drawing because it is desirable to install the muffler at the most appropriate position when the length of the exhaust system for each cylinder is different. This is to prevent the resonance phenomenon due to the entire length of the exhaust system, and is designed to perform the same function as the so-called resonance prevention sub-muffler that has been commonly used in the past. However, if the lengths of the exhaust systems are the same, the position of the small hole O may be the same for each thin-walled tube.

In addition, since one sound deadening space S in the sound deadening cover 20 commonly includes the small holes O formed in each of the thin tubes 19a, there is a time lag in the discharge of exhaust gas from each cylinder. This time lag causes an interference effect, and as a result, it is possible to obtain a sound damping performance that is even higher than that of the conventional one.

Furthermore, a sound-absorbing material 21 is filled in the sound-damping space S on the downstream side in the exhaust gas flow direction within the sound-damping cover 20, and the sound-absorbing action of the sound-absorbing material 21 improves the sound-damping performance. This sound absorbing material 2
As material 1, glass wool, rock wool, etc. are used.

The downstream end of the thin tube 19a is firmly fixedly supported by the recess 20b of the sound deadening cover 20. Note that a tail tube may be provided at the end of the muffler 13, and the exhaust gas may be discharged into the atmosphere from this tail tube.

In this way, an upstream conduit group 11b is formed by connecting a plurality of upstream conduits 11a corresponding to these exhaust ports to each exhaust port of each engine cylinder, and this upstream conduit group 11b is connected to each upstream conduit 11a. If each of the downstream conduits 19a is connected to the muffler 13 via the flexible tube 12 so as to communicate with each other, the exhaust gas coming out of the exhaust port can be discharged through an independent small-diameter exhaust system. Therefore, the exhaust system can be made flat and compact, and the exhaust gas can be discharged straight without any resistance, resulting in no output loss.

In addition, each upstream conduit 11a, thin-walled tube 19a
Since the load on the exhaust pipes is also reduced, the wall thickness of these pipes can be made thinner compared to the thickness of the exhaust pipes of conventional exhaust systems in which exhaust gas is collected in one or two exhaust pipes and discharged. Despite using many books,
Not only does the weight not increase significantly, but the silencer as a whole can be formed flat, so there are fewer restrictions on the mounting position on the vehicle, and the silencer can be mounted at the optimal position for noise reduction.

In particular, since the downstream conduit group connected to the exhaust conduit is covered with a sound-reducing cover and the downstream conduit group is used as a muffler, the exhaust gas contains noise as it flows down the individual downstream conduits forming the downstream conduit group. Since the sound is muted, it can be said to be an elementalized sound damping system, and by simply installing this muffler in the downstream region of the upstream conduit, it can be freely installed in the vehicle as a muffler that exhibits the desired performance. It will be possible.

Furthermore, since the above-mentioned flat silencer is suitable for vehicles having a flat floor surface, such as front-wheel drive vehicles, which have recently been attracting attention, they are most suitable.

Next, another embodiment of the present invention will be described.

As shown in FIG. 10, the muffler is a deformed muffler 4 that is deformed into an arbitrary shape according to the mounting position of the vehicle.
It is also possible to use the modified muffler 40 and the muffler 13 connected by a flexible tube or the like.

Further, as shown in FIG. 11, two wavy plates 50 are combined to form the downstream conduit group 19b, and both wavy plates 50 are covered with a flat sound-absorbing cover 52.
It may be covered with If the sound deadening cover 52 is formed with bulges 52a at short pitches in a direction perpendicular to the longitudinal direction of the silencer, the bulging parts 52a will become a sound deadening space S and the bead effect will increase the rigidity of the sound deadening cover 52. It will also be expensive.

[Effects of the invention] Since the present invention has the configuration as explained above, exhaust gas is discharged smoothly and there is little output loss, and since the muffler is formed flat, there are no restrictions on the mounting position. Less damage is caused by individual conduit exhausts, resulting in less weight and increased durability than conventional exhaust systems. In particular, the downstream conduit group connected to the upstream conduit group is covered with a sound deadening cover, and this downstream conduit group is used as a muffler. By simply installing the muffler in the downstream region of the upstream conduit, it can be freely installed in a vehicle as a muffler that exhibits the desired performance, and versatility in installing the muffler is increased.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a conventional exhaust system, FIG. 2 is a vertical sectional view of the exhaust system according to the present invention, FIG. 3 is a perspective view of a flexible tube, and FIG. 4 is a cross-sectional view of FIG. Figure 5 is a - cross-sectional view of Figure 2;
Fig. 6 is a sectional view of Fig. 2, Fig. 7 is a cutaway perspective view of the main part of Fig. 2, Fig. 8 is a partial vertical sectional view of Fig. 7, and Fig. 9 is a - sectional view of Fig. 8. 10 is a perspective view showing another embodiment of the present invention, and FIG. 11 is a partially cutaway perspective view showing still another embodiment. 11a...upstream conduit, 11b...upstream conduit group,
12... Flexible tube, 13... Silencer, 14, 16... End plate, 19a... Thin wall tube (upstream conduit), 19b... Upstream conduit group, 20...
...Sound-muffling cover, O...Small hole, S...Sound-muffling space.

Claims (1)

[Scope of utility model registration request] It has an upstream conduit through which exhaust gas discharged from a plurality of engine cylinders flows, and a downstream conduit whose one end is communicated with the upstream conduit, and the outside of this downstream conduit is covered with a sound-absorbing cover, and the downstream conduit inside this muffling cover is In the exhaust device that functions as a muffler by opening a small hole that guides a portion of the exhaust gas into a muffling space provided between the muffling cover and the downstream conduit, the upstream conduit is connected to the plurality of engine cylinders. The upstream conduit group is composed of a plurality of upstream conduits each independently connected to each exhaust port, while the downstream conduit has a plurality of downstream conduits connected in series corresponding to each of the plurality of upstream conduits. The downstream conduit group is composed of conduits, and this downstream conduit group is formed by thin-walled tubes arranged in close proximity to each other on the same plane. is covered by the sound deadening cover, and by partitioning the inside of the sound deadening cover, a plurality of spaces are formed as the sound deadening spaces, and each of the small holes of each downstream conduit leading to these sound deadening spaces is one sound deadening space. An exhaust system characterized in that it forms a muffler that is commonly included in a space.