JP2003056340A - Variable exhaust noise structure for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable exhaust noise structure for an engine capable of continuously varying engine exhaust noise with simple operation and capable of preventing lowering of output of the engine. SOLUTION: An end cap 4 forming an atmosphere opening port 3 is fitted onto a tail end of a muffler body 2. An adjusting shaft 7 having a screw part 5 at a front end and a nut 6 at a rear end is rotatably attached on a central shaft supporting part 8 of the end cap 4. A pair of semicircular vane valves 10 are rotatably supported on a supporting shaft 9 fixed on the end cap 4. The vane valve 10 and a moving piece 11 are linked by a link 12. The vane valve 10 is backwardly tilted around the supporting shaft 9 through the link 12 by operating the nut 6. Thus, an exhaust gas passage area between the vane valves 10 and the atmosphere open port 3 is made variable to vary the exhaust noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust structure of an engine that discharges exhaust gas discharged from the engine to the atmosphere. More specifically, the exhaust sound of the engine can be varied as desired. Regarding the structure.

[0002]

2. Description of the Related Art Conventionally, exhaust gas discharged from an engine exhaust port is discharged to the atmosphere through an exhaust structure such as an exhaust pipe, a muffler body or a tail pipe protruding rearward from the muffler body. Since the exhaust gas is discharged at high pressure and high speed, a silencer that reduces exhaust noise is being actively developed. However, for users who use the vehicle as a hobby such as a motorcycle, there is also a need to appropriately adjust the exhaust sound to some extent according to the user's preference. For this reason, for example, as seen in Japanese Utility Model Laid-Open No. 56-124223, a tail cap provided with muffling elements having different exhaust passage lengths, thicknesses, etc. is provided at the exhaust outlet, and the tail cap is appropriately rotated by the user in the circumferential direction. A device is known in which the discharge sound is selected by rotating it to.

[0003]

By the way, the tail cap attached to the rear portion of the exhaust port as in the above-mentioned conventional example is detached and rotated every time it is necessary to change the sound, so that the operation is troublesome. It is difficult to satisfy the tastes of many users because the number of muffling elements having different exhaust passage lengths and thicknesses is limited.

The present invention is intended to solve the above problems, and provides an exhaust sound variable structure capable of changing the exhaust sound steplessly or arbitrarily by a simple operation at the atmosphere opening port of the engine exhaust gas. The purpose is to get. Another object of the present invention is to obtain an exhaust structure capable of easily attaching or removing the exhaust sound variable structure of the present invention to the tail end of an existing muffler body or tail pipe.

[0005]

In the exhaust structure according to claim 1 of the present invention, an end cap 4 is formed at the tail end of a muffler body 2 with an atmosphere opening 3 of an appropriate size on the outer circumference in the circumferential direction.
Is attached so as to cover the tail end of the muffler body 2, and an adjustment shaft 7 having a threaded portion 5 at the front end and a knob 6 at the rear end is rotatably attached to the central shaft support portion 8 of the end cap 4. A pair of semi-circular vane valves 10 are rotatably supported on a support shaft 9 fixed to the front part of the end cap 4 while being pivotally mounted, and the vane valve 10 and the screw portion 5 of the adjusting shaft 7 are supported by the screw shaft 5. The link 12 is connected to the moving piece 11 that is screwed,
If necessary, the knob 6 is operated to rotate the adjustment shaft 7 to move the moving piece 11 back and forth, whereby the vane valve 10 is tilted rearward about the support shaft 9 via the link 12 and the atmosphere opening port 3 is provided. The exhaust sound passage was made variable by varying the area of the exhaust gas passage between and.

In the exhaust structure according to claim 2 of the present invention, an end cap 4 is formed at the tail end of the tail pipe 13 and an atmosphere opening 3 of an appropriate size is formed on the outer circumference in the circumferential direction, at the tail end of the muffler body 2. The adjustment shaft 7 which is attached so as to cover it and has a threaded portion 5 at the front end and a knob 6 at the rear end is rotatably attached to the central shaft support portion 8 of the end cap 4, and the end cap is also attached. A pair of semicircular blade valves 10 are rotatably supported on a support shaft 9 fixed to the front portion of 4,
The vane valve 10 and a moving piece 11 screwed to the threaded portion 5 of the adjusting shaft 7 are connected by a link 12, and the knob 6 is operated to rotate the adjusting shaft 7 as necessary to rotate the adjusting piece 7.
By moving the valve back and forth through the link 12 to tilt the vane valve 10 rearward about the support shaft 9 to change the area of the exhaust gas passage between the blade valve 10 and the atmosphere opening port 3 to change the exhaust sound.

In the exhaust structure according to claim 3 of the present invention, a stopper 14 is provided immediately before the central shaft supporting portion 8 of the adjusting shaft 7, and the portion is expanded between the knob 6 and the rear portion of the central shaft supporting portion 8. Intervening the spring 15

In the exhaust structure according to claim 4 of the present invention, a sound absorbing material 17 such as glass wool is interposed between the muffler body 2 and the porous baffle tube 16 inside the muffler body 2, and at the rear end of the sound absorbing material 17. There is a cover plate 18 between the muffler body 2 and the baffle tube 16.
The outer peripheral end of the end cap 4 was detachably attached to the No. 8.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view of a motorcycle provided with an exhaust structure of the present invention, FIG. 2 is an enlarged vertical sectional view of an essential portion of the present invention, FIG. 3 is a view corresponding to FIG. 2 showing an operating state, and FIG. 4 is another embodiment. FIG. 3 is an enlarged vertical cross-sectional view illustrating an essential part corresponding to FIG. 2.

In FIG. 1, the exhaust gas discharged from the engine passes through an exhaust pipe 1 and a muffler body 2 and is exhausted to the atmosphere through an atmosphere opening port 3 at the tail end of the muffler body 2.

Referring to FIG. 2, in the engine exhaust structure of the present invention, a substantially bowl-shaped end cap 4 is attached to a cover plate 18 provided at the tail end of the muffler body 2 with bolts or the like so as to cover the tail end of the muffler body 2. Attach detachably. The end cap 4 is formed with an atmosphere opening port 3 of an appropriate size in an inclined portion 4a on the outer circumference in the circumferential direction at an appropriate interval in the circumferential direction.

Reference numeral 7 denotes an exhaust sound adjusting shaft, which has a threaded portion 5 at the front end thereof.
And a knob 6 is provided at the rear of the other end. This adjustment shaft 7
Is rotatably attached to the central shaft supporting portion 8 of the end cap 4. Specifically, the adjusting shaft 7 is integrally provided with a stopper 14 immediately in front thereof, and the knob 6 and the central shaft supporting portion are provided. 8 is a structure in which a spring 15 for expanding the portion is interposed between the rear portion and the rear portion. The stopper 14 may have, for example, a set ring structure, and the spring 15 may be any other elastic body (rubber body, disc spring) or the like as long as it is a member for expanding the space between the knob 6 and the central shaft supporting portion 8. Further, both sides of the central shaft supporting portion 8 may be rotatably attached by a set ring.

Further, a support shaft 9 which vertically penetrates the end cap 4 in the radial direction is fixed to the front portion of the end cap 4.
Further, a pair of semi-circular vane valves 10 are attached to the support shaft 9 on the center side.
Is rotatably supported by a shaft, and the outer peripheral side faces the inner wall of the baffle tube 16.

Further, a screw portion 5 is formed on the front portion of the adjusting shaft with a certain length, and a moving piece 11 is screwed and screwed to the screw portion 5. Further, a link 12 is swingably attached to the rear surface of the vane valve 10 at a symmetrical position about the support shaft 9, and the other end of the link 12 is connected to the moving piece 11. The connecting portion between the link 12 and the moving piece 11 is also swingably attached.

The present invention is a muffler body 2 as shown in FIG.
Even in an exhaust structure of an engine that discharges to the atmosphere through one or a plurality of tail pipes 13 protruding further rearward, the exhaust sound adjusting structure of FIG. 2 can be provided at the atmosphere opening port to obtain the present invention.

That is, an end cap 4 having an atmosphere opening 3 of an appropriate size on the outer circumference in the circumferential direction is attached to the tail end of the tail pipe 13 so as to cover the tail end of the muffler body 2, and a screw is attached to the front end. An adjusting shaft 7 having a portion 5 and a knob 6 at its rear end is rotatably attached to a central shaft supporting portion 8 of the end cap 4, and is attached to a supporting shaft 9 fixed to the front portion of the end cap 4. A pair of semicircular vane valves 10
Is rotatably supported, and the blade valve 10 and a moving piece 11 screwed to the screw portion 5 of the adjusting shaft 7 are connected by a link 12, and the knob 6 is operated as necessary to adjust the adjusting shaft. 7 is rotated to move the moving piece 11 back and forth, so that the vane valve 10 is tilted rearward about the support shaft 9 via the link 12 to make the area of the exhaust gas passage with the atmosphere opening port 3 variable. The exhaust noise can be adjusted variably.

Inside the muffler body 2, a sound absorbing material 17 such as glass wool is interposed between the muffler body 2 and the porous baffle tube 16 inside, and the muffler body 2 and the baffle tube are at the rear end of the sound absorbing material 17. The space between 16 is covered with a closing plate 18, and the outer peripheral end of the end cap 4 is detachably attached to the closing plate 18.

As described above in detail, the present invention has the above-mentioned structure. Therefore, when the adjusting shaft 7 supported by the end cap 4 is rotated by operating the knob 6, the moving piece 11 moves in the front-back direction with respect to the end cap 4. Since the blade valve 10 moves and is supported by the support shaft 9, the link valve 12 causes the blade valve 10 to have a shape in which the arcuate tip end portion is bent rearward as shown in FIGS. As a result, the area of the exhaust gas passage between the blade valve 10 and the atmosphere opening port 3 becomes variable, and the flow velocity and the exhaust pressure can be changed to change the exhaust sound. Therefore, the user can appropriately change the emitted engine exhaust sound according to his or her preference.

Moreover, the present invention is extremely simple because it is possible to adjust the engine exhaust sound to the user's preference steplessly by simply rotating the knob 6. Furthermore, the structure is simple and there is little risk of breakdown.

[0020]

According to the exhaust structure of the first aspect of the present invention, the muffler body 2 is provided at the tail end thereof with an end cap 4 formed with an atmosphere opening 3 of an appropriate size in the outer circumference in the circumferential direction of the muffler body 2. The adjustment shaft 7 is attached so as to cover the tail end, has a threaded portion 5 at the front end, and has a knob 6 at the rear end.
Is rotatably attached to the central shaft supporting portion 8 of the end cap 4, and a pair of semicircular vane valves 10 is rotatably supported on a supporting shaft 9 fixed to the front portion of the end cap 4. The vane valve 10 and a moving piece 11 screwed to the threaded portion 5 of the adjusting shaft 7 are connected by a link 12, and the knob 6 is operated to rotate the adjusting shaft 7 as necessary to rotate the moving piece. By moving 11 forward and backward, the vane valve 10 is tilted rearward about the support shaft 9 via a link 12 to make the exhaust gas passage area between the blade valve 10 and the atmosphere opening port 3 variable, thereby making the exhaust sound variable. Therefore, the user can appropriately change the emitted engine exhaust sound according to his / her preference. Moreover, the present invention is extremely simple because it is possible to adjust the engine exhaust sound to the user's preference steplessly by simply rotating the knob 6. Furthermore, the structure is simple and there is little risk of breakdown. Moreover, since the vane valve 10 has a tilted state in which the semicircular surface is arranged along the flow of the exhaust gas, the exhaust flow is smooth and the exhaust pressure is low even when the exhaust gas passage area with the atmosphere opening port 3 is narrowed. The impact can be kept to a minimum.

According to the exhaust structure of the second aspect of the present invention, the tail cap of the muffler body 2 is provided with an end cap 4 formed at the tail end of the tail pipe 13 with an atmosphere opening 3 of an appropriate size on the outer circumference in the circumferential direction. Attach it so that it covers the edges,
An adjustment shaft 7 having a screw portion 5 formed at the front end and a knob 6 provided at the rear end is rotatably attached to a central shaft supporting portion 8 of the end cap 4 and is fixed to the front portion of the end cap 4. A pair of semicircular vane valves 10 are rotatably supported on a shaft 9, and the vane valve 10 and a moving piece 11 screwed to a screw portion 5 of the adjusting shaft 7 are connected by a link 12. If necessary, the knob 6 is operated to rotate the adjustment shaft 7 to move the moving piece 11 back and forth, whereby the vane valve 10 is tilted rearward about the support shaft 9 via the link 12 and the atmosphere opening port 3 is provided. Since the exhaust gas passage area between and is made variable so that the exhaust sound is also variable, even in the exhaust structure of the engine which emits to the atmosphere via the tail pipe 13 or a plurality of tail pipes 13 protruding rearward from the muffler body 2. The present invention can be carried out. Can.

According to the exhaust structure of the third aspect of the present invention, the stopper 14 is provided immediately in front of the central shaft supporting portion 8 of the adjusting shaft 7 and the portion is expanded between the knob 6 and the rear portion of the central shaft supporting portion 8. Since the spring 15 for opening is interposed, the regulation in the axial direction is easy and the mounting is easy.

According to the fourth aspect of the present invention, the sound absorbing material 1 such as glass wool is provided between the muffler body 2 and the porous baffle tube 16 inside the muffler body 2.
7, the rear end of the sound absorbing material 17 and the space between the muffler body 2 and the baffle tube 16 are covered with a closing plate 18, and the outer peripheral end of the end cap 4 is detachably attached to the closing plate 18. The present invention can be implemented without significantly changing the muffler body. Further, since the end cap 4 of the present invention is detachably attached to the closing plate 18 with bolts, it is possible to easily replace parts in the muffler body.

[Brief description of drawings]

FIG. 1 is a schematic side view of a motorcycle having an exhaust structure of the present invention.

FIG. 2 is an enlarged vertical sectional view of an essential part of the present invention.

3 is a view corresponding to FIG. 2 showing the operating state of FIG.

FIG. 4 is an enlarged vertical sectional view of an essential part corresponding to FIG. 2 showing another embodiment.

[Explanation of symbols]

2 muffler body 3 Atmosphere opening 4 End cap 5 screw part 6 knobs 7 Adjustment axis 8 shaft support 9 spindles 10 blade valve 11 moving pieces 12 links 13 tail pipe 14 Stopper 15 spring 18 Plate

Claims (4)

[Claims] 1. In an exhaust structure of an engine for discharging exhaust gas discharged from an engine exhaust port to the atmosphere through an exhaust pipe 1 and a muffler body 2, a tail end of the muffler body 2 is appropriately sized in a circumferential outer circumference. Is attached to the muffler body 2 so as to cover the tail end of the muffler body 2, and the adjustment shaft 7 having a screw portion 5 at the front end and a knob 6 at the rear end is attached to the end cap 4. Cap 4
And a pair of semicircular vane valves 10 are rotatably supported on a spindle 9 fixed to the front part of the end cap 4 and are rotatably attached to the central shaft supporting portion 8. The link 12 is connected to the moving piece 11 screwed to the screw portion 5 of the adjusting shaft 7, and the knob 6 is operated to rotate the adjusting shaft 7 to move the moving piece 11 back and forth as necessary. As a result, the blade valve 10 is supported by the support shaft 9 via the link 12.
The exhaust sound variable structure of the engine characterized in that the exhaust sound is made variable by making the exhaust gas passage area between the exhaust gas and the atmosphere opening port 3 variable by rearwardly tilting. 2. An exhaust structure of an engine, wherein exhaust gas discharged from an engine exhaust port is released into the atmosphere through an exhaust pipe 1, a muffler body 2, and a tail pipe 13 protruding rearward from the muffler body 2.
At the tail end of 3, the atmosphere opening port 3 of appropriate size on the outer circumference in the circumferential direction
The end cap 4 formed with the end cap 4 is attached so as to cover the tail end of the muffler body 2, and the adjustment shaft 7 having the screw portion 5 at the front end and the knob 6 at the rear end is attached to the central shaft of the end cap 4. A pair of semicircular vane valves 10 are rotatably supported on a supporting part 8 and rotatably supported on a supporting shaft 9 fixed to the front part of the end cap 4. Moving piece 11 screwed to the screw portion 5 of 7
The link 6 is connected to the above and the knob 6 as necessary.
Is operated to rotate the adjustment shaft 7 to move the moving piece 11 back and forth, and the blade valve 1 is moved through the link 12.
An exhaust sound variable structure for an engine, characterized in that the exhaust sound is made variable by tilting 0 about the support shaft 9 rearward to make the area of the exhaust gas passage with the atmosphere opening port 3 variable. 3. A stopper 14 is provided immediately in front of the central shaft supporting portion 8 of the adjusting shaft 7, and a spring 15 for expanding the portion is provided between the knob 6 and the rear portion of the central shaft supporting portion 8. The exhaust sound variable structure for an engine according to claim 1 or 2. 4. A sound absorbing material 17, such as glass wool, is interposed between the muffler body 2 and the porous baffle tube 16 inside the muffler body 2, and the sound absorbing material 17 is at the rear end between the muffler body 2 and the baffle tube 16. Plate 18
The exhaust sound variable structure for an engine according to any one of claims 1 to 3, characterized in that the outer peripheral end of the end cap (4) is detachably attached to the closing plate (18).