JP2003206738A - Muffler for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a muffler for an engine with an excellent point to bring out engine performance and capable of appropriately changing the performance. <P>SOLUTION: A first cylindrical muffler body 10 which has an introductory port 12 and an exhaust outlet 13 at one end 11 and a wall surface 14a at another end 14, and a cylindrical second muffler 20 which has a plurality of expansion chambers from an exhaust introductory port 22 at one end 21 to an exhaust outlet 28 at another end 27. The muffler body 10 is connected with the muffler body 20 in series. A valve 30 with variable opening and an opening 35 are provided at the end 14 of the side having the wall surface 14a of the first muffler body 10. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The claimed invention relates to an engine muffler (silencer) suitable for use in a motorcycle or the like.

[0002]

2. Description of the Related Art FIG. 9 shows a conventional muffler (FIG. 9A), a side view (FIG. 9B) and a rear view (FIG. 9C) of a motorcycle equipped with the muffler. The muffler 1'of FIG. 9 (a) is
Inside the cylindrical muffler body 70, a plate with holes (punching metal) 71 and a partition plate (baffle plate) 72.
A plurality of expansion chambers are configured by attaching 73, baffle pipes 74, 75, 76 and the like. The muffler body 70 is formed of inner and outer double cylinders 70a and 70b (inner 70b is made of punching metal), and a sound absorbing material (glass wool) 70c is filled between them. While the exhaust gas flows from the exhaust gas introduction port 77 at one end to the exhaust gas exhaust port 78 at the other end, the exhaust sound is generated along with the expansion of the exhaust gas in each expansion chamber and also at the partition plate between the chambers. The generated reflected wave interferes with the traveling wave, and is further absorbed by the sound absorbing material to gradually reduce the sound pressure.

In order to form a muffler which is excellent in noise reduction effect (exhaust noise reduction function) and is preferable in terms of engine performance (output), the outer diameter of the muffler body 70 is often increased as shown in the example. . If the outside diameter is increased, the volume of each expansion chamber can be increased, and multiple baffle pipes 74, 75, and 76 can be mounted on one partition plate 73 as shown in the figure, and the reflected wave with a high sound deadening effect can be obtained. This is because the front and rear expansion chambers can be positively created. Also,
This is also because the diameter of each of the pipes 74, 75, and 76 can be increased, which reduces resistance to exhaust gas and makes it difficult to reduce engine performance.

Generally, a muffler is required to have a sound deadening effect, a characteristic of reducing exhaust resistance to maximize engine performance, and a compact and easy arrangement. Since it is difficult to improve these characteristics together, conventional mufflers usually set each characteristic to an appropriate level according to the application of the engine and the installation location of the muffler. .

[0005]

The muffler 1'having a large diameter as shown in FIG. 9 (a) is satisfactory in relation to the noise reduction effect and the engine performance, but since it has a considerable volume, the arrangement size and occupied space are large. Tend to cause problems with. Further, when used in the motorcycle X as shown in FIG. 9 (b), there are often problems with appearance. In other words, if the muffler 1'has a large diameter, the width of the vehicle body including it will be as shown in FIG.
It tends to be large as shown in (c), and it becomes difficult to design an ideal vehicle body in which the vehicle body is made compact and the weight portions are gathered near the center of gravity. Further, the muffler 1'of the motorcycle X also has a role of making an impression of the appearance of the motorcycle X together with exhaust pipes such as the exhaust pipe 62 and the joint pipe 64 leading to the muffler 1 ', but the large diameter of the muffler 1'provides an external appearance. There may be a loss of lightness.

In a muffler as shown in FIG. 9 (a), the above-mentioned plurality of characteristics set according to the use of the engine are
It is difficult to change it appropriately according to the operating state of the engine. For example, when operating at high output (high load), the characteristics related to engine performance are generally important, unlike when operating at low output. It is difficult for the muffler of FIG. 9 (a) to make a change so as to focus on the improvement of.

The claimed invention is compact and brings an advantage in appearance, and is also excellent in terms of noise reduction effect and engine performance, and the characteristics relating to engine performance are appropriately changed according to the operating state of the engine. It is intended to provide a muffler for an engine that can do this.

[0008]

A muffler for an engine according to a first aspect of the present invention is: a) a tubular shape having an exhaust inlet and an exhaust outlet at one end and a wall surface portion at the other end. No. 1 muffler body, and a second tubular body having a plurality of expansion chambers from an exhaust inlet port at one end to an exhaust outlet port at the other end.
The muffler body is connected in series (that is, so that the exhaust gas flows sequentially from the former to the latter, not in parallel), and b) the opening is provided at the end of the first muffler body on the side having the wall surface portion. An opening is provided together with a variable valve (that is, a valve whose opening can be changed manually or automatically by direct or remote operation).

This engine muffler is used for motorcycles and A
In addition to vehicles such as TV (four-wheel buggy), ships, generators,
When connected to the engine of various work machines and general-purpose machines, it exhibits the following functions.

The characteristics of reducing exhaust resistance to exert high engine performance (output) can be appropriately changed according to the operating state of the engine. This is because the variable opening valve and the opening are provided at the one end of the first muffler body as described in b) above. That is, when the valve is closed, the entire amount of exhaust gas is passed through the insides of the first and second muffler bodies to increase the exhaust gas pressure (back pressure) and increase the torque during low rotation (at the same time, the muffling effect is also provided. If the valve is opened, a part (or the whole amount) of the exhaust gas can be smoothly discharged to the outside through the opening through only the first muffler body. So, for example,
It is possible to close the valve when operating at low power to make the engine performance a so-called low rotation type, while opening the valve when operating at high power to direct the engine performance to high rotation.

It is excellent in sound deadening effect and can effectively remove low frequency components and middle and high frequency components in exhaust noise. The low-frequency component is easily removed because the first muffler body has the exhaust inlet and the exhaust outlet at one end and the wall surface portion at the other end as described in a) above. is there. That is, as a result of the exhaust sound of the exhaust gas that has entered the first muffler body from the inlet being reflected by the wall surface portion, the traveling wave and the reflected wave effectively interfere with each other in the first muffler body. As in a) above, the second muffler body is connected in series to the first muffler body so that the middle and high frequency components can be effectively removed. This is because it also passes through the inside of the 2 muffler body. The second muffler body has a general structure having a plurality of expansion chambers and the like extending from the exhaust gas inlet port at one end to the exhaust gas outlet port at the other end, so that the performance of removing middle and high frequency components is improved. It's easy.

It is also easy to obtain high engine performance by reducing exhaust resistance generally (that is, including when the valve is closed). This is because, as described above, the sound deadening effect is excellent, and therefore, the sound deadening effect and the engine performance can be balanced by adopting a configuration in which the exhaust gas easily passes smoothly.

A compact and easy arrangement can be made. This is because two muffler bodies as described in a) above are used instead of one muffler body having a large outer diameter. That is, each muffler body can be made small in diameter, and thus the required space for each muffler body and the entire muffler can be reduced. This also has an advantage in appearance, and when this muffler is attached to a vehicle such as a motorcycle or an ATV, it gives a light impression.

Particularly, the engine muffler according to the second aspect of the invention is used as a valve according to the above b), the opening is closed by the force of the spring, and the opening is opened when the pressure of the exhaust gas acting on the pressure receiving portion exceeds the force of the spring. It is characterized by having an automatic opening and closing type that opens.

According to this muffler, the valve of the above b) is closed during the low output operation so that the engine can easily exert the low rotational torque (at the same time, the sound deadening effect is enhanced), while the valve is opened during the high output operation. The preferred operation of opening and maximizing engine performance at high rpm is performed automatically. The exhaust pressure is usually high when the engine is operated at high output and is low when the engine is operated at low output.Therefore, when the engine is operated at high output, the exhaust pressure is increased and acts strongly on the pressure receiving part. When the force of the spring is exceeded, the opening is opened (so that part or all of the exhaust gas is discharged without passing through the second muffler body).

In this muffler, the valve has a simple structure and is easily constructed at low cost. As the above-mentioned valve, a valve body that can close the opening and a spring that presses the valve body with an appropriate force to close the opening are combined, and a pressure receiving portion that receives exhaust pressure in a direction opposite to the spring force is provided in the valve body. This is because it is sufficient if it is installed in. Since the structure is simple, it is easy to provide heat resistance, and therefore, excellent durability can be exhibited even when the heat exchanger is arranged in the first muffler body.

The engine muffler according to claim 3 is
Further, a tail pipe is connected to the opening provided together with the valve. For example, the muffler 6 shown in FIG. 8 uses the tail pipe 15E and corresponds to the muffler of this claim.

With this muffler, the exhaust noise can be suppressed to a sufficiently low level even when the above-mentioned valve is opened to discharge a part or all of the exhaust from the first muffler body to the outside during high-power operation. . This is because the exhaust gas discharged to the outside via the valve passes through the inside of the tail pipe connected to the opening, although it does not pass through the second muffler body. The tail pipe generally reduces the exhaust noise, though it depends on the inner diameter and the length thereof. Therefore, the exhaust noise level can be optimized by using an appropriate size and material.

The engine muffler described in claim 4 is: a) a cylindrical first muffler body having an exhaust inlet and an exhaust outlet at one end and a wall surface portion at the other end. A tubular second having a plurality of expansion chambers from an exhaust gas inlet at one end to an exhaust gas outlet at the other end
Connect the muffler body in series (that is, so that the exhaust gas flows sequentially from the former to the latter, not in parallel), and c) from the exhaust port of the first muffler body to the exhaust gas intake port of the second muffler body. In the pipe (connection pipe between both muffler bodies), a valve with variable opening (that is, a valve whose opening can be changed directly or by remote operation) is provided. Characterize.

This engine muffler is also used for motorcycles and A
In addition to vehicles such as TV (four-wheel buggy), ships, generators,
When connected to the engine of various working machines and general-purpose machines, it exhibits the same preferable effects as the muffler of claim 1.
That is, since the muffler of claim 1 has the characteristics of the above a), it is excellent in silencing effects from low-frequency components to medium / high-frequency components, and reduces exhaust resistance to bring out engine performance well. Moreover, the whole is compact and its arrangement is easy.

Further, the characteristic of lowering the exhaust resistance and exerting high performance (output) of the engine can be appropriately changed according to the operating state of the engine. This is because, as described in c) above, a valve whose opening degree is variable is provided in the pipe from the outlet of the first muffler body to the exhaust inlet of the second muffler body. That is, when the opening of the valve is lowered (closed), the exhaust flow passage from the first muffler body to the second muffler body is narrowed (so-called back pressure is increased). While the torque can be increased (at the same time, the muffling effect is also improved), if the valve opening is increased, the condition in which the flow passage is throttled is released (reverse pressure is reduced), so that the exhaust gas can easily pass through it The engine output is more likely to be exerted during rotation.

In particular, the engine muffler according to claim 5 is a valve of the above-mentioned c), in which a remotely operated valve connected to an operating means through a rope (wire, rope, string, chain, etc.) is attached. It is characterized by that.

In this muffler, even when the valve is opened and closed by using a precise operating means (servo motor, etc.),
The means can have sufficient durability. This is because it is not necessary to arrange the operating means near the muffler which becomes high in temperature due to exhaust because the operating means is connected to the valve via a cord. By using a precise and highly-functional operating means, for example, it is possible to perform automatic control such that the valve of c) is set to an optimum opening according to the engine speed, throttle opening, and the like.

An engine muffler according to a sixth aspect of the present invention is the muffler of the above, in which b) an opening is provided at an end of the first muffler body on the side having the wall surface portion together with a variable opening valve, and c). A valve whose opening degree is variable is provided in a pipe extending from the discharge port of the first muffler body to the exhaust gas introduction port of the second muffler body.

Since this muffler has both the characteristics of b) and c) described above, it has characteristics such that exhaust resistance is reduced and engine performance (output) is enhanced, depending on the operating conditions of the engine. Can be adjusted more flexibly and appropriately. For example, by appropriately setting the opening degree of the valve in c) above, it is determined whether the characteristic is low rotation and high torque for low rotation, or high rotation for high engine performance. In addition to defining the basic characteristics of the muffler, b) above according to changes in exhaust pressure.
It is possible to follow a sudden change in the engine output by automatically opening and closing the valve. In such a case, it is possible to give the engine an output-like instantaneous force while freely setting the basic performance of the muffler.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to FIGS. Unless otherwise specified, "right", "left", "front", and "rear" described below refer to the right, left, front, and rear of the motorcycle body in the direction of travel.

First, FIG. 1 is an overall vertical cross-sectional view of the muffler 1 (FIG. 1A) and partial detailed views (FIGS. 1B to 1D) showing respective parts thereof, and FIG. FIG. 2 is a side view (FIG. 2A) and a rear view (viewed from the rear, FIG. 2B) of the motorcycle X1 to which the muffler 1 is attached.

The muffler 1 of FIG. 1 is constructed by connecting two muffler bodies each having a cylindrical outer shape, that is, a first muffler body 10 and a second muffler body 20 in series.

The first muffler body 10 is provided with an exhaust inlet 12 and an exhaust outlet 13 at one end 11 and an end 14 forming a disk-shaped wall portion at the other end 14. By providing the plate 14a and the valve 30 that is normally kept closed, only one expansion chamber is formed inside. In the first muffler body 10, the total amount of exhaust gas that has entered from the inlet port 12 is normally folded back in the middle, and proceeds as shown by the black arrow in the figure to the outlet port 13.
As it goes to, the exhaust sound also reaches the end portion 14, is reflected by the wall surface portion of the end plate 14a, and returns to the end portion 11 side. Therefore, inside the first muffler body 10,
The traveling wave and the reflected wave of the exhaust sound are overlapped with each other, and the sound pressure is canceled out based on the phase difference between them. Moreover, the distance from one end 11 to the other end 14 is long (about 3
00 mm or more. However, since it is changed according to the frequency range to be reduced), a sufficient phase difference can be taken and exhaust noise can be effectively reduced centering on low frequency components. Therefore, even if the diameter of the first muffler body 10 is small, excellent silencing performance is exhibited.

The more specific structure of the first muffler body 10 is as follows. First, the cylindrical body body
A sound absorbing material 10c made of glass wool is attached to the inside of the cylinder 10a made of a stainless plate, and an inner cylinder 10b made of punching metal made of stainless steel is further inserted inside to integrate the cylinder 10a. At the end portion 14, the valve 30 is arranged as described above so as to be supported by the end plate 14a. The valve 30 has a variable opening degree and is configured as shown in FIGS. 1 (c) and 1 (d).
That is, first, the support shaft 32 is reciprocally inserted into the valve seat body 34, and the disk-shaped valve body 31 with the packing 31a is attached to one end (outside air side) thereof.
A locking piece 32a is fixed to the other end of the support shaft 32 (inside the muffler body 10), and a coil spring 33 is compressed and attached between the locking piece 32a and the valve seat body 34. The valve seat 34 is provided with a plurality of openings 35 so that they can be closed by the valve 31. Based on this configuration, the valve 30
When the exhaust pressure in the muffler body 10 is low, the valve body 31 closes the opening 35 of the valve seat body 34 by the force of the spring 33 (see the upper half of FIG. 1C), and the exhaust pressure is If it becomes higher than a predetermined value, the valve body 3 is resisted against the force of the spring 33.
1 moves to open the opening 35 (see the lower half of FIG. 1C). A partition plate 15a having a short tube 15 at the center is provided outside the valve 30, so that the opening 3
When 5 is opened, part of the exhaust gas in the first muffler body 10 is exhausted to the outside via the short pipe 15. When the exhaust gas is discharged by opening the valve 30 in this way, the above-described effect on noise reduction is weakened, but the resistance to the exhaust gas is reduced, so that the engine can easily exhibit high output.
The components of the valve 30 are made of metal having high heat resistance and oxidation resistance such as stainless steel. End plate 1
4a and the partition plate 15a are also made of stainless steel,
It is attached to the inside of the cylinder 10a (or 10b) by welding. The other end 1 of the first muffler body 10
A partition plate 11a having a flat portion and having a U-shaped (or J-shaped) cross-sectional portion in a circumferential shape so as to facilitate welding with a cylinder 10a or the like is attached to 1, and an opening inside thereof is
A pipe 64 provided with an exhaust inlet 12 and an exhaust outlet 13 and a connecting pipe 16 (integrating both) are inserted and welded.

The pipe 64 and the connecting pipe 16 are not separately inserted into the partition plate 11a, but are shown in FIG. 1 (a).
As described above, the partition plate 1 is integrated inside the latter so as to include the former concentrically (not necessarily in the exact concentric state).
1a (and thus in the body). That is, a hole 16a is opened in a part of the connecting pipe 16 in which a thick pipe is bent in a U shape, the pipe 64 is passed inside the hole 16a, and the entire circumference is welded to the hole 16a. Then, in order to further stabilize the integration of the pipe 64 and the connecting pipe 16, as shown in FIG. 1B, several pieces of the supporting member 11b are welded to connect the pipe 64 and the connecting pipe 16. When the inlet 12 and the outlet 13 are concentrically stacked in this way,
By making the connecting pipe 16 thick enough in the portion having the pipe 64 inside (at the maximum, it matches the diameter of the partition plate 11a), not only the inlet 12 but also the outlet 1
3 and the subsequent exhaust gas passage can have a wide cross-sectional area, and the exhaust gas flow can be made smooth. At the same time, when the concentric arrangement described above is taken, the partition plate 11 at the end 11 is
The welding of the pipe 64 and the connecting pipe 16 to a is also facilitated. In this example, the diameter of the connecting pipe 16 is slightly reduced in the portion where the pipe 64 is not provided inside, and the discharge port 1
The opening cross-sectional area after 3 is made substantially constant.

In the inside of the connecting pipe 16 connecting the first muffler body 10 and the second muffler body 20, as shown in FIG.
As described above, the valve 40 whose opening degree is variable is also provided.
The valve 40 includes the support shaft 4 supported by the wall of the connecting pipe 16.
2 is a butterfly type in which a disc-shaped valve element 41 is attached. A rotary lever 43 is attached to the support shaft 42 outside the connecting pipe 16, and two wire cables 45 for operation are connected to the rotary lever 43. When any one of the wire cables 45 is pulled, the valve body 41 together with the support shaft 42 undergoes angular displacement in the connecting pipe 16, and the connecting pipe 1
The opening and closing of the exhaust flow path is realized within 6. Rotary lever 43
Spring return system and wire cable 4
The same opening / closing operation can be performed by using only one. The valve body 41, the support shaft 42, and the like that form the valve 40 are also made of a metal having high heat resistance and oxidation resistance, such as stainless steel. When the exhaust passage is opened and closed in this way, the exhaust pressure (back pressure) in the first muffler body 10 fluctuates accordingly, so that the muffler 1 exhibits the characteristics related to the output of the engine (at the same time, the muffling effect). It can be appropriately changed and adjusted during driving. For example, valve 40
When is fully opened, the back pressure becomes low and it becomes easier to exhibit the high output of the engine. On the other hand, when the valve 40 is closed, the back pressure increases and such characteristics are weakened, and the output torque of the engine at low rotation speed is reduced because the intake air-fuel mixture is difficult to be discharged when the intake and exhaust valves overlap. Increases (at the same time, the muffling effect also increases). Separately, if the spring 33 (FIG. 1 (c)) used for the valve 30 in the first muffler body 10 is made soft (with a small spring constant), the valve 40 in the connecting pipe 16 is fully closed. In this case, the exhaust amount is exhausted from the valve 30 and the opening 35 with a low resistance, so that the output of the engine is easily exhibited in the high rotation range.

The first muffler body 10 is connected through the connecting pipe 16.
The second muffler body 20 connected to the exhaust port 13 is connected to the exhaust inlet port 22 (downstream end of the connecting pipe 16) at one end portion 21 to the exhaust outlet port 28 at the other end portion 27 by a baffle plate or the like. It is a general type muffler body in which a plurality of expansion chambers and the like are formed. Specifically, first, the body main body is formed of inner and outer double cylinders 20a and 20b (made of stainless steel; the inner 20b is punched metal), and a sound absorbing material (glass wool) 20c is filled between them. Inside the inner cylinder 20b, a partition plate 23 made of punching metal and a baffle pipe 24 are provided as shown in the figure.
A partition plate 24 having a, a partition plate 25 having openings 25a at several places, and a partition plate 26 having baffle pipes 26a and openings 26b at several places are fixed by plug welding or the like. One end 2 corresponding to the upstream side of exhaust gas
In No. 1, the partition plate 21 in which the above connecting pipe 16 is welded
a is welded and fixed to the cylinder 20a, and at the other end 27, a partition plate 27a that also serves as a support for the pipe 26a is provided in the cylinder 2a.
It is welded and fixed to 0a.

In the muffler body 20, the exhaust gas is used as an expansion chamber between the partition plates, and a space surrounded by the partition plate 26, the baffle pipe 26a and the partition plate 27a is a resonance chamber, and the exhaust gas exhaust port 28 ( It is discharged from the downstream end of the pipe 26a). Exhaust sound is reduced mainly in the middle and high frequency components by the action of each expansion chamber, the resonance chamber, and the sound absorbing material 20c. As described above, since the low-frequency component is well removed in the first muffler body 10, the second muffler body 20 does not need to have a large diameter. Since a substantially linear exhaust flow is made inside, the pressure loss of the exhaust in the second muffler body is relatively small.

The muffler 1 of FIG. 1 is excellent in the following points in addition to the point that the low to high frequency components in the exhaust sound can be effectively reduced as described above. That is, since a large opening cross-sectional area can be given to the exhaust inlet 12 and the exhaust 13 of the first muffler body 10, and a substantially linear exhaust flow can be formed in the second muffler body 20, It is easy to draw out the output of the engine by reducing the resistance of. Further, based on the combination of the thin muffler bodies 10 and 20, the degree of freedom in layout is higher than that of the thick single-type muffler, and it is easy to realize a compact and aesthetically pleasing arrangement. Since the two valves 30 and 40 having variable opening degrees are provided, it is possible to appropriately adjust the output characteristics and the like according to the engine operating state and the like.

The motorcycle X1 shown in FIG. 2 uses the muffler 1 of FIG. 1 in the exhaust system in view of the above advantages. That is, the four-cylinder four-cycle engine 61 is mounted below the fuel tank 67 in the motorcycle X1, and an exhaust pipe 62, a manifold 63, and an exhaust pipe such as a joint pipe 64 are connected to its exhaust port 61a. Moreover, the muffler 1 is connected to those terminal portions.

The structure of the exhaust pipe and the like is as follows. First, from the engine 61, four exhaust pipes 62, which are equal in number to the number of cylinders, are extended toward the lower front portion, and are connected to a manifold 63 provided below the engine 61. The manifold 63 has four inlet-side openings and two outlet-side openings, and the downstream ends of the four exhaust pipes 62 are integrated with the two pipes (joint pipes) 64 by way of these. To connect. One of these two pipes 64 is shown in FIG.
・ As shown in (b), it is placed on the left side of the vehicle body, and the other one is shown in Fig. 1.
Place it on the right side of the vehicle as shown in (b). The muffler 1 is connected to each of the pipes 64 arranged on the left side and the right side, using their respective downstream ends as the exhaust gas inlet 12 shown in FIG.

As shown in FIGS. 2A and 2B, the muffler 1
Are arranged in parallel with the second muffler body 20 with the first muffler body 10 on the lower side, and are on the side of the rear wheel 8 and above the axle (the driver seat 68 and the rear seat 6).
9 (below 9), with an angle (exhaust outlet 2
I attached it by raising the back side with 8. In addition to mounting the muffler 1 at such a position and posture, each muffler body 10/20 has a small diameter (each diameter is 70
.About.130 mm), and as shown in FIG. 2 (b), the muffler bodies 10 and 20 are arranged in parallel and close to the side of the vehicle body.
In addition to being able to make a sufficient bank (slope) when traveling,
It has the advantage that the vehicle width is small and the heavy parts are concentrated near the center. Related to that, it is preferable because it has a lightness and a speedy appearance. Needless to say, the motorcycle X1 is also good in terms of exhaust noise and engine performance (output) based on the configuration and function of the muffler 1 itself.

In the motorcycle X1, the opening of the valve 40 arranged in the connecting pipe 16 is controlled by using the servo motor 50 as an operating means. The rotary lever 51 is rotated by the servo motor 50, and the displacement is detected by the wire cable 4
By transmitting to the rotary lever 43 of the valve 40 via 5, the valve 40 (of which the valve body 41) is opened and closed. As shown in FIGS. 2A and 2B, the valve 40
The rotary lever 43 is arranged on the surface of the connecting pipe 16 near the center of the vehicle body, and the wire cable 45 connected to the rotary lever 43 is also passed inside the vehicle body frame (step holder or the like) 65 (close to the vehicle body center). Since the servo motor 50 is also arranged so as to be hidden under the driver's seat 68, the device for operating the valve 40 is hardly visible from the outside, which is advantageous in appearance. It is also preferable as a condition of use that the servo motor 50, which is a precision instrument, can be placed away from the muffler 1, which is one of the heat sources.

An operation signal corresponding to a signal relating to a traveling state such as the speed of the motorcycle X1 is input to the servo motor 50 to control the opening degree of the valve 40 according to the traveling state. For example, when running at high speed, it is easy to open the valve 40 fully to make the engine 61 exhibit a high output, and at low speed, make the valve 40 slightly closed so that the low torque of the engine 61 can be easily made (at the same time, the muffler 1 has a muffling effect. To be strong). In addition, muffler 1
In addition to the valve 40 described above, the valve 30 is provided in the first muffler body 10 as shown in FIG. 1A and as described above. Therefore, when the output of the engine 61 suddenly rises, the valve 30 opens and a high load (high Output) Smooth operation can be achieved.

FIG. 3 shows a muffler 2 which is partially different from the muffler 1 of FIG. That is, the muffler 2 has no valve in the connecting pipe 16A as shown in FIG.
As shown in (b), it differs from the above-described muffler 1 (FIG. 1) in that the heat insulating cover 37 is attached to the valve 30A in the first muffler body 10A. First muffler body 10A
The configuration of the second muffler body 20A itself, the connection form of the pipe 64 (the inlet 12A) and the connecting pipe 16A (the outlet 13A) to the second muffler body 20A, the configuration and functions of the valve 30A other than the heat insulating cover 37, and the like are shown in FIG. Since it is the same as the one described above, the way in which the exhaust (the course is shown by a black arrow in the figure) and the exhaust sound in the muffler 2 proceed is the same as that in the case of FIG. Of course, such a muffler 2 is also suitable for use in a motorcycle or the like.

The valve 30A has substantially the same structure as the valve 30 of FIG. 1 as described above, but as shown in FIG. 3B, a locking piece for mounting the spring 33 between the valve 30 and the valve seat body 34. A heat insulating cover 37 having a flat plate portion and a tubular portion like a bowl is attached on the support shaft 32 integrally with 32a. Since the tubular portion of the heat insulating cover 37 covers the outside of the spring 33, the heat resistance and the oxidation resistance of the spring 33 are supplemented, and the valve 30A can be used for a long period of time. Since the length of the tubular portion of the heat insulating cover 37 is appropriately set, as shown in (b), when the valve body 31 closes the opening 35 (upper half of the figure) and opens (lower half of the figure). ), The outside of the spring 33 is effectively covered.

As shown in FIG. 3 (a), since no valve is provided in the connecting pipe 16A, the characteristics of the muffler 2 in use regarding the engine output and the like are as follows.
It is adjusted only by the above-mentioned valve 30A provided in 0A. The valve 30A, like the valve 30 described above, is an automatic opening / closing type that opens when the exhaust pressure in the muffler body 10A becomes a certain value or more, so when the engine output is low, the valve 30A is closed to exert a low rotational torque and output. When it increases, it can be opened to reduce the exhaust resistance and cause the engine to exhibit instantaneous high output.

Next, FIG. 4 shows a muffler 3 having a slight difference from the muffler 2 of FIG. That is, in the muffler 3, the formation mode of the exhaust introduction port 12B and the exhaust port 13B with respect to the first muffler body 10B is shown in FIG.
(And FIG. 1). That is, the pipe 64 connected to the one end 11B of the first muffler body 10B.
The connection pipe 16B and the connecting pipe 16B are not concentrically integrated, but they are separately inserted into the partition plate 11Ba and fixed. The configurations of the first muffler body 10B and the second muffler body 20B themselves are the respective muffler bodies 10A of FIG.
Same as 20A, the exhaust (the path is shown by a black arrow in the figure) and the way of the exhaust sound in each inside are the same as those in FIG. 3, and therefore each muffler body 10
The functions relating to the exhaust resistance (engine output characteristics) and the like in B and 20B are equivalent to those of the muffler 2 in FIG.

A general-purpose pipe can be used for the muffler 3 as the connecting pipe 16B and the pipe 64.
There is an advantage that a manufacturing process such as special processing or welding and passing through the pipe 64 is unnecessary. In the illustrated example, the valve 30B arranged in the first muffler body 10B has the same structure as the valve 30 shown in FIGS. 1 (c) and 1 (d).

FIG. 5 is a diagram showing the vicinity of one end portion 14C of the first muffler body 10C for the muffler 4 which can also be arranged in a motorcycle or the like. This muffler 4 is also provided with an exhaust inlet from one end 14C formed as shown in the figure.
A first muffler body 10C formed in a tubular shape toward the other end having a discharge port (not shown), and a cylindrical second muffler having a plurality of expansion chambers from one exhaust introduction port to the other exhaust discharge port A body (not shown) is connected in series, and a valve 30C having a variable opening degree is provided in the muffler body 10C as shown in the figure.

In the valve 30C, as shown in FIG. 5A, first, an end plate 34C having a wall surface portion that easily reflects exhaust sound and an opening 35C is fixed to the inside of the cylinder 10b by welding, and the end plate 34C is also fixed. A plate-shaped valve body 31C is attached to the outside (outside air side) of 34C so as to close the opening 35C. As shown in Fig. 5 (b), the valve body 31C includes a support shaft 32 fixed to the end plate 34C.
It is supported by C in a swingable state, and is normally pressed onto the end plate 34C by a spring 33C from the outside so as to close the opening 35C.

The valve 30C having such a structure is also the same as the above-described valves 30, 30A, 30B, and the first muffler body 1
It opens and closes according to the exhaust pressure in 0C. That is, when the exhaust pressure is low, the force of the spring 33C causes the valve element 3 to
When the opening 35C is closed at 1C and the exhaust pressure becomes equal to or higher than a certain value, the valve body 31C is displaced against the spring 33C to open the opening 35. When the opening 35 of the valve 30C is opened, a part of the exhaust gas in the muffler body 10C is discharged to the outside through the short pipe 15C as well, so that the muffler 4
It can be said that, during use, the output characteristics and the like can be appropriately adjusted according to the engine operating state and the like.

The muffler 5 shown in FIG. 6 includes many parts common to the muffler 1 of FIG. 1 such as being equipped with the first and second muffler bodies 10D and 20D, but eliminates the valve in the muffler body 10D and connects the connecting pipe. It is an example in which a part of the operating mechanism of the valve in 16D is changed. Each muffler body 10
The connection form of the pipe 64 (inlet port 12D) and the connecting pipe 16D (outlet port 13D) to the D / 20D and the configuration of the second muffler body 20D are exactly the same as those of the muffler 1 of FIG. However, there is no difference from that of FIG. 1 except that there is no valve inside. Therefore, the way in which the exhaust gas (the path is shown by a black arrow in the figure) and the exhaust sound (the path in the muffler body 10D is shown by an outline arrow) in the muffler 5 basically proceeds in the case of FIG. (When the valve 30 in FIG. 1 is closed). Such a muffler 2 also exhibits the same characteristics as in the case of FIG. 1 with respect to the output of the engine and the like, and is therefore suitable for use in a motorcycle or the like.

However, inside the first muffler body 10D, no valve is provided at the end 14D on the side opposite to the end 11D having the inlet 12D and the outlet 13D.
D is closed with a cap 15X including a flat wall surface portion. A butterfly-type variable valve 40D including a disc-shaped valve body 41D and a support shaft 42D is provided inside the connecting pipe 16D from the first muffler body 10D to the second muffler body 20D. In order to move the valve element 41D of the valve 40D, the lever 43D is integrated with the support shaft 42D outside the connecting pipe 16D, and the operating wire cable 45D is connected thereto. By pulling this wire cable 45D, the valve body 41D is rotationally displaced, thereby opening and closing the exhaust passage in the connecting pipe 16.

In the muffler 5 of FIG. 6, the muffler 1 to
Unlike 3 there is no valve in the first muffler body,
The characteristics of the muffler 5 in use regarding the engine output and the like are adjusted only by the valve 40D in the connecting pipe 16D. Since this valve 40D does not automatically open and close instantaneously according to the pressure of the exhaust gas, it does not follow the instantaneous output fluctuation of the engine, but by performing an appropriate remote operation via the wire cable 45D. It is possible to appropriately set and change the basic characteristics of the muffler, that is, whether the engine performance should be exhibited at low speed or at high speed.

The manner in which the valve 40D is attached to the connecting pipe 16D in the muffler 5 of FIG. 6 is as shown in FIG. 7 (a). The connecting pipe 16D has a so-called monaca structure in which a pair of semicircular tubular members formed of a stainless steel plate are formed into a tubular shape by welding the joint portions 16a provided in the longitudinal direction. In the example of a), the connecting pipe 16 is provided at a portion where the joint 16a is not provided.
A support shaft 42D is passed through D and supported. Valve body 41D
Is connected to the support shaft 42D of the connecting pipe 16
The lever 43D is connected to the support shaft 42D outside the connecting pipe 16D, and the spring 43D is engaged with the lever 43D so that the valve element 41D and the like have angular restoration properties.

The valve 40D may be attached to the connecting pipe 16D as shown in FIG. 7B or 7C, for example. That is, FIG. 7B is an example in which the valve body 41D and the like are supported by inserting the support shaft 42D between the joint portions 16a of the connecting pipe 16D having the Monaca structure. In addition, FIG. 7C shows that the connecting pipe 16D is integrally formed by hydroforming or casting, and the support shaft 42 is formed on the pipe wall.
This is an example in which D is penetrated and supported. In addition, FIG.
The mounting mode of the valve 40D as shown in (c) can be applied not only to the muffler 5 of FIG. 6 but also to other types of muffler, for example, the muffler 1 shown in FIG.

The motorcycle X2 shown in FIG. 8 includes a muffler 5
As the first muffler body 10E and the second muffler body 2
It is attached as a separate piece from OE. That is, the muffler 6 of the motorcycle X2 is the muffler body 1 having the same structure as that of FIG. 1, FIG.
Although it has 0E and 20E, the two are not arranged side by side, but rather are arranged separately on the lower and side portions of the vehicle body and are connected by a long connecting pipe 16E. Specifically, first, the first muffler body 10E is provided in the lower portion of the vehicle body (position below the engine 61 and the transmission),
A joint pipe 64 and a connecting pipe 16E that are concentrically integrated are inserted and fixed into the one end 11E. Then, as shown in FIG. 8A, the second muffler body 20E is connected to the downstream end of the connecting pipe 16E by extending the connecting pipe 16E rearward. The second muffler body 20E is on the side of the rear wheel 8 and above the axle thereof (driver's seat 6).
8 and a position below the rear seat 69) with a diagonal orientation (the exhaust outlet 28E side is raised).

As shown in FIG. 8B, the muffler body 10E
A valve 30E having a variable opening is attached to the inside (end 14E on the side opposite to the end 11E to which the pipe 64 and the like are connected), and a long tail pipe 15E is connected to the part following the valve 30E. The valve 30E has the same structure as that shown in FIG. 1 (the structure may be the same as that shown in FIGS. 3 and 5). The valve 30E closes the opening by the force of the spring, and automatically when the exhaust pressure exceeds the spring force. The opening is opened to let the exhaust gas flow out. Further, the tail pipe 15E, from the end portion 14E of the first muffler body 10E provided in the lower part of the vehicle body,
50c to the side of the rear wheel 8 along with the muffler body 20E
It is a stainless steel pipe having a length of m or more, and is suitable for exhaust discharged to the outside through the valve 30E without passing through the second muffler body 20D by exerting an appropriate amount of resistance on the exhaust flow. Demonstrate a good muffling effect.

Since no valve is provided inside the connecting pipe 16E, the characteristics of the muffler 6 regarding the engine output during use, etc. are the same as those of the muffler 2 of FIG. Valve 3 in 10E
It is automatically adjusted by opening and closing 0E. That is, FIG.
This muffler 6 also has a valve 3 while the engine output is low.
When the engine output rises, the valve 30E is opened to reduce the exhaust resistance to reduce the exhaust resistance, thereby making it possible to cause the engine to instantaneously output a high output. Including such points, it can be said that the muffler 6 and the motorcycle X2 having the muffler 6 are excellent in various aspects such as improvement of engine performance, reduction of exhaust noise, downsizing of vehicle body size, and further improvement of appearance. The valve 40 of FIG. 1 and the valve 40D of FIG.
It is needless to say that it is preferable to provide such a variable opening degree valve inside the connecting pipe 16E in the example of FIG. 8 in order to flexibly adjust the characteristics of the muffler 6 regarding the engine output and the like.

Although some forms have been shown above with reference to the drawings, the embodiment of the invention is not limited to these. In addition to the above explanation, for the purpose of changing and adjusting the characteristics relating to engine performance and exhaust noise, for example, a) by forming appropriate small holes in the end plate for reflected wave formation, Part of the exhaust gas is always discharged directly to the outside through the hole. (B) The position of the exhaust gas introduction port in the first muffler body (that is, the pipe having the introduction port to the first muffler body). C) The punching metal or other perforated plate (baffle plate) is provided between the exhaust inlet in the first muffler body and the above-mentioned end plate for forming the reflected wave. ), Or various sound absorbing materials are arranged as appropriate (thus the first
Increase the middle and high frequency component removal characteristics of the muffler body), d) Match the length and thickness (and mounting location) of the first muffler body or the second muffler body to the dimensions of the other muffler body. E) The muffler 1 of FIG. 1 is provided with a small hole in the pipe 64 inside the connecting pipe 16 so that a limited part of the exhaust gas does not pass through the first muffler body. So that it goes into the second muffler body, f) The number of the first or second muffler body is appropriately changed according to the number of cylinders of the engine, etc. G) According to the number of cylinders of the engine, etc. It is also preferable to take measures such as appropriately changing the number of pipes (such as the pipe 64 in FIG. 1) and connecting pipes (such as the connecting pipe 16 in FIG. 1) connected to one muffler body.

The muffler of the invention can be used in the following ways. H) It can also be used in the exhaust system of a two-cycle engine. However, in that case, in order to obtain the exhaust effect and scavenging effect peculiar to the two-cycle engine, connect the chamber that has a tapered wall surface at the end and generates the reflected pulsation pressure inside the muffler. Preferably. I) It can also be used in the exhaust system of engines other than motorcycles. (G) It may be connected to an exhaust pipe so that the exhaust gas flows from the second muffler body to the first muffler body (for example, in the example of FIG. 1, from the exhaust outlet 28 to the inlet 12 opposite to the arrow). .

[0059]

The engine muffler described in claim 1 has the following effects.・ The characteristics related to the engine performance are appropriately changed according to the operating condition of the engine, for example, the low rotational torque is exerted at high power during low power operation, while the valve is opened at high power operation to exert high engine power. can do. This is because a valve with variable opening and an opening are provided at the end of the first muffler body on the side where the wall surface is located. -It is possible to effectively remove low-frequency components in addition to the removal of high-frequency components in exhaust sound as in the conventional muffler. This is because, in the first muffler body, the exhaust sound of the exhaust gas that has entered through the introduction port is reflected by the wall surface portion at the other end, and the traveling wave and the reflected wave effectively interfere with each other.・ It is easy to extract engine output by reducing the resistance to exhaust gas. Also, based on the combination of narrow muffler bodies, there is a high degree of freedom in layout, and it is easy to realize a compact and aesthetically pleasing arrangement.

With the muffler for an engine according to claim 2, in particular, it is preferable that: • the low running torque of the engine is easily exerted during low power operation, while the high engine performance is exerted during high power operation. It can be done automatically. -Since the valve structure is simple, it is possible to easily construct a valve with excellent durability at low cost.

According to the engine muffler of claim 3, the exhaust noise can be suppressed sufficiently low even when the exhaust is exhausted from the first muffler body by opening the valve during high power operation. can do.

The engine muffler described in claim 4 also has the following effects, like the muffler described in claim 1. That is, the characteristics relating to the engine performance based on the exhaust resistance can be appropriately changed according to the operating state of the engine and the like. This is because a valve whose opening degree is variable is provided in the pipe from the discharge port of the first muffler body to the exhaust gas introduction port of the second muffler body.・ In addition to its excellent sound-reducing effect from low-frequency components to medium- and high-frequency components, it reduces exhaust resistance to maximize engine performance, and is compact in size and easy to arrange.

According to the engine muffler of the fifth aspect, particularly, even when the valve is opened / closed by using a precise operating means, the means can have sufficient durability. This is because the above-mentioned valve is operated remotely, so that it is not necessary to dispose operating means in the vicinity of the high temperature muffler.

According to the engine muffler of claim 6, since the valves are provided at two preferable places, the characteristics such as reducing exhaust resistance and enhancing engine performance (output) can be obtained. Can be adjusted more flexibly and appropriately. For example, it is possible to give the engine an output-like instantaneous force while freely setting the basic performance of the muffler.

[Brief description of drawings]

FIG. 1 is a diagram showing a muffler 1 which is one embodiment for carrying out the invention, wherein FIG. 1 (a) is an overall vertical cross-sectional view of the muffler 1, and FIG. 1 (b) is a view from the arrow b in the same (a). Partial detail drawing,
The same (c) is a detailed cross-sectional view of the end portion 14 of the muffler 1 of the same (a) (the upper half shows the valve 30 closed, the lower half shows the valve 30 open), the same (d). [Fig. 3] is a detailed view showing a d-d arrow in the same (c).

2 is a view showing a motorcycle X1 to which the muffler 1 of FIG. 1 is attached, FIG. 2 (a) is a side view, and FIG. 2 (b) is a rear view (viewed from the rear).

FIG. 3 (a) is an overall vertical sectional view showing a muffler 2 according to an embodiment of the invention. Further, the same (b) is a detailed sectional view of the muffler 2 near the end 14A of the same (a) (the upper half is in a state where the valve 30A is closed, and the lower half is in a state where the valve 30A is open).

FIG. 4 is an overall vertical sectional view showing a muffler 3 according to an embodiment of the invention.

FIG. 5A is a vertical cross-sectional view showing a part (near the end portion 14C) of the muffler 4 according to an embodiment of the invention. Moreover, the same (b) is a bb arrow line view in the same (a).

FIG. 6 is an overall vertical sectional view showing a muffler 5 according to an embodiment of the invention.

7 (a) to 7 (c) are cross-sectional views (VII-VII cross-sectional views in FIG. 6) showing an attachment mode of the valve 40D in the muffler 5 of FIG.

FIG. 8 (a) is a side view showing a muffler 6 according to an embodiment of the invention together with a motorcycle X2, and FIG. 8 (b) is a detailed view showing an arrow b in FIG. 8 (a). is there.

9 (a) is a longitudinal sectional view showing a conventional muffler 1 ', FIG. 9 (b) is a side view of a motorcycle X equipped with the muffler 1', and FIG. 9 (c) is a side view of the motorcycle X. It is a rear view.

[Explanation of symbols]

1-6 Muffler 10, 10A, 10B, 10C, 10D, 10E 1st
Muffler body 12, 12A, 12B, 12D Inlet port 13, 13A, 13B, 13D Outlet port 14a, 34C End plate (wall surface part) 16, 16A, 16B, 16D, 16E Connection pipe (pipe) 20, 20A, 20B, 20D・ 20E Second muffler body 22 Exhaust gas inlet port 28 ・ 28B ・ 28E Exhaust gas outlet port 30 ・ 30A ・ 30B ・ 30C ・ 30E Valve 33 ・ 33C Spring 35 ・ 35C Opening 40 ・ 40D Valve 45 ・ 45D Wire cable (cord) 50 Servo motor (operating means) X1 and X2 motorcycles

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3G004 AA02 AA03 AA04 AA05 AA06                       AA07 BA00 BA01 BA03 BA08                       CA04 CA12 DA01 DA24 EA01

Claims (6)

[Claims] 1. A cylindrical first member having an exhaust inlet and an exhaust outlet at one end and a wall surface portion at the other end.
A muffler body and a cylindrical second muffler body having a plurality of expansion chambers are connected in series from an exhaust gas inlet port at one end to an exhaust gas outlet port at the other end, and a first muffler body is provided. A muffler for an engine, wherein an opening is provided together with a valve having a variable opening degree at an end portion on the side having the wall surface portion. 2. The valve is an automatic opening / closing type which closes the opening by the force of a spring and opens the opening when the pressure of the exhaust gas acting on the pressure receiving portion exceeds the force of the spring. The engine muffler according to claim 1. 3. The tail pipe is connected to the opening provided together with the valve.
Muffler for the engine described in. 4. A tubular first member having an exhaust inlet and an exhaust outlet at one end and a wall surface portion at the other end.
A muffler body and a cylindrical second muffler body having a plurality of expansion chambers are connected in series from an exhaust gas inlet port at one end to an exhaust gas outlet port at the other end, and a first muffler body is provided. A muffler for an engine, characterized in that a valve having a variable opening degree is provided in a pipe extending from the exhaust port to the exhaust introduction port of the second muffler body. 5. The muffler for an engine according to claim 4, wherein the valve is a remote control type that is connected to an operating means via a cord. 6. An opening is provided at an end portion of the first muffler body on the side having the wall surface portion together with a valve with a variable opening degree, and from an exhaust port of the first muffler body to an exhaust gas introduction port of the second muffler body. The engine muffler according to any one of claims 1 to 5, wherein a valve having a variable opening degree is provided in each of the pipes extending therethrough.