WO2018173388A1 - Exhaust device for vehicle - Google Patents

Abstract

Provided is an exhaust device for a vehicle in which the detection accuracy of an oxygen sensor can be maintained even when the outer shell of a muffler has a water-draining hole. In this exhaust device for a vehicle (1), which has a muffler (30) for reducing the noise of discharging combustion gas produced by an internal combustion engine (13) of the vehicle 1, an oxygen sensor (43) is provided inside the muffler (30), and a water-draining hole (45) serving as a through-hole is provided in an outer shell (34) of the muffler (30). The muffler (30) is provided with an auxiliary chamber (54, 64) for holding air surrounding the water-draining hole (45). Viewed from the side of the vehicle body, the water-draining hole (45) is provided at the lowest end part (A) of the muffler (30). The auxiliary chamber (54, 64) is provided to the inner side or outer side of the muffler (30). The muffler also has a bulging part (55, 65) that bulges in the through direction of the water-draining hole (45), and a small-diameter communication channel (56, 66) allows the bulging part (55, 65) to communicate with the inner side or outer side of the muffler (30). The communication channel is placed to the vehicle-body-rearward side of the bulging part.

Description

Vehicle exhaust system

The present invention relates to an exhaust system of a vehicle, and more particularly to an exhaust system of a vehicle in which a catalyst device and an oxygen sensor for detecting an oxygen concentration of combustion gas are attached inside a muffler.

Conventionally, there is known an exhaust system of a vehicle in which a catalyst device for purifying combustion gas and an oxygen sensor for detecting the oxygen concentration in the muffler are disposed inside the muffler for reducing the exhaust noise of engine combustion gas. It is done.

Patent Document 1 discloses a configuration in which a water draining hole for discharging water generated in the muffler to the outside is provided on the outer shell of the muffler provided with a catalyst device and an oxygen sensor.

JP, 2016-160915, A

However, if a water draining hole communicating the inside and the outside of the muffler is provided in the outer shell of the muffler, it is conceivable that outside air intrudes into the interior of the muffler from the water draining hole to affect the sensor output of the oxygen sensor. Patent Document 1 has not considered such a subject.

An object of the present invention is to solve the problems of the prior art and to provide an exhaust system of a vehicle capable of maintaining detection accuracy by an oxygen sensor even when a water draining hole is provided in an outer shell of a muffler.

In order to achieve the above object, the present invention relates to an exhaust system of a vehicle having a muffler (30) for reducing exhaust noise of combustion gas produced by an internal combustion engine (13) of the vehicle (1). An oxygen sensor (43) is provided in the inside, a water draining hole (45) as a through hole is provided in the outer shell (34) of the muffler (30), and the water in the muffler (30) A first feature resides in that sub-chambers (54, 64) for holding air around the extraction hole (45) are provided.

The water draining hole (45) has a second feature in that it is provided at the lowermost end of the muffler (30) in a side view of the vehicle body.

A third feature is that the sub-chamber (54) is provided inside the muffler (30).

Further, the sub-chamber (54) communicates the inside of the bulging portion (55) with the bulging portion (55), the bulging portion (55) bulging in the penetrating direction of the water draining hole (45), A fourth feature lies in having a small diameter communication passage (56).

A fifth feature is that the sub-chamber (64) is provided outside the muffler (30).

Further, the sub-chamber (64) communicates a bulging portion (65) bulging in the penetration direction of the water draining hole (45), the bulging portion (65) and the outside of the muffler (30). A sixth feature resides in having a small diameter communication passage (66).

A seventh feature is that the communication passage (66) is disposed toward the vehicle body rear side of the bulging portion (65).

Further, the interior of the muffler (30) is divided into a plurality of rooms (31, 32, 33) by a plurality of partition walls (41, 42), and the water draining hole (45) corresponds to the oxygen sensor (43). The eighth feature resides in that the chamber (33) is provided in the chamber (31) farthest away in the combustion gas path from the chamber (33) provided.

A ninth feature is that the sub-chamber (54, 64) is formed by fixing a cover member (50, 60) to the outer shell (34) of the muffler (30).

According to the first feature, in the exhaust system of a vehicle having a muffler (30) for reducing the exhaust noise of combustion gas produced by the internal combustion engine (13) of the vehicle (1), the oxygen sensor inside the muffler (30) (43) is provided, and a drain hole (45) as a through hole is provided in the outer shell (34) of the muffler (30), and the drain hole (45) is provided in the muffler (30). Since the sub-chamber (54, 64) for holding the air around the) is provided, it prevents the outside air from staying inside the sub-chamber by staying inside the sub-chamber even if the outside air enters from the water drain hole. Can. Thereby, it is possible to prevent the outside air from invading the inside of the muffler from affecting the sensor output of the oxygen sensor.

According to the second feature, since the water draining hole (45) is provided at the lowermost end of the muffler (30) in a side view of the vehicle body, the water generated in each part in the muffler is collected by gravity By providing a drain hole at the position, the water discharge efficiency can be enhanced.

According to the third feature, since the sub chamber (54) is provided inside the muffler (30), it is possible to provide the sub chamber without affecting the appearance of the muffler. Also, the sub-chamber can be protected from the external force applied to the muffler.

According to the fourth feature, the sub-chamber (54) is a bulging portion (55) bulging in the penetration direction of the water draining hole (45), the bulging portion (55) and the muffler (30). Because the small diameter communication passage (56) which connects the inside of) with, it becomes easy to stay outside air inside the bulging part when outside air invades from the water drainage hole, outside air becomes water when the internal pressure of the muffler rises. It becomes easy to be discharged from the hole.

According to the fifth feature, since the sub chamber (64) is provided outside the muffler (30), the sub chamber can be provided without affecting the internal space of the muffler. Further, the drainage hole can be hidden from the outside, and the drainage hole can be protected from the external force applied to the muffler.

According to the sixth feature, the sub-chamber (64) is a bulging portion (65) bulging in the penetration direction of the water draining hole (45), the bulging portion (65) and the muffler (30). The small diameter communication passage (66) which communicates with the outside of the casing) makes it easy for the outside air to stay in the bulging part when the outside air enters from the communication passage, and also causes the communication passage when the internal pressure of the muffler rises. It becomes easy to be discharged from

According to the seventh feature, since the communication passage (56, 66) is disposed toward the vehicle body rear side of the bulging portion (55, 65), it acts from the vehicle body front side of the sub chamber It can be made insusceptible to the influence of internal pressure fluctuation and running wind.

According to the eighth feature, the interior of the muffler (30) is divided into a plurality of rooms (31, 32, 33) by a plurality of partition walls (41, 42), and the water draining hole (45) is Since the oxygen sensor (43) is provided in the chamber (31) farthest apart in the combustion gas path from the chamber (33) provided with the oxygen sensor (43), the water drain hole and the oxygen sensor are separated. Even when outside air intrudes from the hole, the influence on the sensor output of the oxygen sensor can be suppressed.

According to the ninth feature, since the sub-chamber (54, 64) is formed by fixing the cover member (50, 60) to the outer shell (34) of the muffler (30), the configuration is simple. It is possible to set up a sub-chamber.

FIG. 1 is a left side view of a motorcycle to which an exhaust system of a vehicle according to an embodiment of the present invention is applied. It is a partial cross section perspective view of a muffler. It is a perspective view of a covering member seen from the inside of a shell. It is a top view of a covering member. FIG. 5 is a cross-sectional view taken along line VV of FIG. 4; It is a perspective view of a muffler concerning a modification of this embodiment. It is a top view of a covering member. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 7; It is a perspective view of a muffler concerning a 2nd modification of this embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a left side view of a motorcycle 1 to which an exhaust system of a vehicle according to an embodiment of the present invention is applied. A steering stem (not shown) is pivotally supported by a head pipe 6 provided at the front end of the vehicle body frame 3. A pair of left and right front forks 11 rotatably supporting the front wheel WF is supported by a top bridge 5 and a bottom bridge 7 fixed to a steering stem. A steering handle 4 is fixed to the top of the top bridge 5, and a front fender 10 covering the top of the front wheel WF is attached to the front fork 11.

At a lower rear portion of the vehicle body frame 3, a pivot 23 pivotably supporting a swing arm 16 rotatably supporting the rear wheel WR is provided. The rear end portion of the swing arm 16 is suspended via a rear cushion 20 to a rear frame 22 extending upward from the rear of the pivot 23. The driving force of the engine 13 suspended by the vehicle body frame 3 is transmitted to the rear wheel WR via the drive chain 17.

A fuel tank 2 is disposed above the engine 13, and a front cowl 8 supporting a headlight 9 is attached to the front of the head pipe 6. A seat 21 and a rear cowl 19 are disposed above the rear frame 22, and a rear fender 18 is attached to the rear lower portion of the rear cowl 19.

The combustion gas of the parallel four-cylinder engine 13 is led to the muffler 30 formed by the expansion chamber through the exhaust pipe 12 and the collecting pipe 14 and discharged outward from the rear end of the muffler 30. Exhaust pipe 12, collecting pipe 14, and muffler 30 collectively constitute an exhaust system of the vehicle. In the outer shell of the muffler 30, a water draining hole 45 is formed as a through hole for discharging the water generated inside the muffler 30 outward. The drainage hole 45 is provided at the lowermost end A of the muffler 30.

FIG. 2 is a partial cross-sectional perspective view of the muffler 30. As shown in FIG. The interior of the muffler 30 covered with the metal shell 34 is divided into a first chamber 31, a second chamber 32 and a third chamber 33 by the first partition 41 and the second partition 42. An inlet pipe 35 connected to the collecting pipe 14 is connected to the front end of a catalyst device (catalyzer) 39 supported by the first partition 41 and the second partition 42. The rear end portion of the catalyst device 39 projects into the third chamber 33, and the sensor portion of the oxygen sensor 43 to which the wiring 44 is connected projects inside the third chamber 33.

The combustion gas having passed through the catalytic converter 39 is discharged outward from the rear end of the exhaust pipe 36 through a long exhaust path constituted by the first muffling pipe 40, the second muffling pipe 37 and the third muffling pipe 38. Ru.

Although water is generated inside the muffler 30 according to the state of the atmosphere and the operating state of the engine, in the present embodiment, water is formed at the lower end A (see FIG. 1) of the muffler 30 in a side view of the vehicle body. Since the removal holes 45 are provided, the moisture generated in the second chamber 32 and the third chamber 33 also gathers in the drainage holes 45 by gravity, and is efficiently discharged. In addition, notches 41a and 42a through which the water generated in the second chamber 32 and the third chamber 33 passes are provided at lowermost end portions of the first partition 41 and the second partition 42, respectively.

Here, even when the water draining hole 45 and the oxygen sensor 43 are spaced apart, if the internal pressure of the muffler 30 fluctuates and outside air enters the muffler internal from the water draining hole 45, the sensor output of the oxygen sensor 43 is detected. It is possible to affect. In order to cope with this problem, the present invention is characterized in that a covering member 50 covering the opening periphery of the water draining hole 45 is attached to the inner peripheral surface of the outer shell 34. According to this covering member 50, it is possible to prevent the outside air from entering the interior of the muffler 30 from the water draining hole 45, and to maintain the detection accuracy of the oxygen sensor 43.

FIG. 3 is a perspective view of the covering member 50 viewed from the inside of the outer shell 34. 4 is a plan view of the covering member 50, and FIG. 5 is a cross-sectional view taken along the line VV of FIG. The cover member 50 made of a metal plate or the like includes a flat flange portion 52 for fixing the cover member 50 to the outer shell 34 and a top plate portion 51 having a predetermined three-dimensional shape. In the present embodiment, the cover member 50 is fixed to the outer shell 34 by the three spot welds 53 applied to the flange portion 52.

By fixing the cover member 50 to the outer shell 34, the sub-chamber 54 for holding the air around the drainage hole 45 is formed inside the top plate portion 51. The sub chamber 54 has a bulging portion 55 that bulges in the penetration direction of the water drain hole 45 and a small diameter communication passage 56 that communicates with the bulging portion 55. According to this configuration, the bulging portion 55 can hold a predetermined amount of air, and the cross-sectional area of the communication passage 56 communicating with the interior of the muffler 30 is small. It becomes difficult to diffuse inside the muffler 30. In addition, since the outside air tends to stay in the bulging portion 55, the outside air is easily discharged from the water drain hole 45 when the internal pressure of the muffler 30 rises. Furthermore, since the communication passage 56 is disposed on the vehicle body rear side of the bulging portion 55, it becomes less susceptible to the internal pressure fluctuation that acts from the vehicle body front side of the covering member 50.

According to the above-described configuration, it is possible to provide the sub-chamber 54 that suppresses the entry of the outside air only by fixing the covering member 50 that covers the opening periphery of the drain hole 45. In addition, since the cover member 50 is attached to the inside of the muffler 30, the sub-chamber 54 can be provided without affecting the appearance of the muffler 30, and the sub-chamber 54 is protected from the external force applied to the muffler 30. can do.

FIG. 6 is a perspective view of a muffler 30 according to a modification of the present embodiment. This variation is characterized in that a covering member 60 which covers the periphery of the drain hole 45 is attached to the outside of the muffler 30. When the cover member 60 is provided on the outside of the muffler 30, the sub-chamber can be provided without affecting the internal space of the muffler 30. In addition, the drain hole 45 is concealed from the outside, and the drain hole 45 can be protected from the external force applied to the muffler 30. Furthermore, it is also conceivable to use the cover member 60 as a protector when the muffler 30 is in contact with the ground, or to use it as an accent on the design.

FIG. 7 is a plan view of the covering member 60. FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. The covering member 60 has the same basic shape as the covering member 50 shown in the first embodiment, and has a flat flange 62 for fixing the covering member 60 to the outer shell 34 and a predetermined three-dimensional shape. It comprises a top plate portion 61. The cover member 60 is fixed to the outer shell 34 by a TIG welded portion 63 provided at the outer edge of the flange portion 62.

By fixing the cover member 60 to the outer shell 34, a sub chamber 64 for holding the air around the drain hole 45 is formed inside the top plate portion 61. The sub chamber 64 has a bulging portion 65 which bulges in the penetrating direction of the water drain hole 45 and a small diameter communication passage 66 which communicates with the bulging portion 65. According to this configuration, the bulging portion 65 can hold a predetermined amount of air, and the outside air entering from the communication passage 66 does not easily reach the drainage hole 45, and the outside air does not easily enter the inside of the muffler 30. Further, since the communication passage 66 is disposed on the vehicle body rear side of the bulging portion 65, the influence of the traveling wind acting from the vehicle body front side of the cover member 60 is less likely to be exerted.

FIG. 9 is a perspective view of a muffler 30a according to a second modified example of the present embodiment. The same reference numerals as above indicate the same or equivalent parts. The present modification is characterized in that a reinforcing member 70 made of a thin metal plate member or the like is provided inside the outer shell 34 of the third chamber 33 of the muffler 30a. A relatively large pressure will be applied to the third chamber 33 to which the combustion gas is initially fed through the inlet pipe 35 and the catalyst device 39, but the reinforcing member 70 may be placed along the inner circumferential surface of the outer shell 34. By arranging, the rigidity around the third chamber 33 can be enhanced without affecting the appearance of the muffler 30a, and the occurrence of vibration, exhaust leak and the like due to exhaust pulsation of the combustion gas can be prevented. The material and shape of the reinforcing member 70 can be variously modified.

As described above, according to the exhaust system of the vehicle according to the present invention, the sub-chamber for holding the air around the drainage hole is provided around the drainage hole provided in the outer shell of the muffler. It is easy for the outside air which is going to intrude from the vent hole to stay in the sub chamber, and the diffusion to the inside of the muffler is suppressed. Thereby, it is possible to prevent the outside air from invading the inside of the muffler and affecting the sensor output of the oxygen sensor.

The shape of the vehicle, the shape and internal structure of the muffler, the size and position of the drainage hole, the structure and position of the oxygen sensor, the shape and material of the cover member, the shape of the sub chamber, the bulging portion and the communication passage The shape and the like are not limited to the above embodiment, and various modifications are possible. For example, the cover member may be fixed to the muffler shell by a fastening member or the like, or may be integrally formed with the muffler shell. The exhaust system of a vehicle according to the present invention is not limited to a motorcycle, and can be applied to various vehicles such as a three-wheeled vehicle and a four-wheeled vehicle.

DESCRIPTION OF SYMBOLS 1 ... Motorcycle (vehicle), 13 ... engine (internal combustion engine), 30 ... muffler, 34 ... outer shell, 43 ... oxygen sensor, 45 ... water drain hole, 50, 60 ... covering member, 52, 62 ... flange portion, 54, 64 ... auxiliary chamber, 55, 65 ... bulging portion, 56, 66 ... communication passage, 31, 32, 33 ... 1st, 2nd, 3rd chamber, 41, 42 ... 1st, 2nd partition, A ... bottom end of the muffler

Claims (9)

In an exhaust system of a vehicle having a muffler (30) for reducing exhaust noise of combustion gas produced by an internal combustion engine (13) of the vehicle (1),
An oxygen sensor (43) is provided inside the muffler (30),
The outer shell (34) of the muffler (30) is provided with a drain hole (45) as a through hole,
An exhaust system of a vehicle, wherein the muffler (30) is provided with an auxiliary chamber (54, 64) for holding air around the water draining hole (45). The exhaust system of a vehicle according to claim 1, wherein the drain hole (45) is provided at the lowermost end (A) of the muffler (30) in a side view of the vehicle body. The exhaust system of a vehicle according to claim 1 or 2, wherein the sub-chamber (54) is provided inside the muffler (30). The sub-chamber (54) has a bulging portion (55) bulging in the penetrating direction of the water draining hole (45), and a small diameter communicating the bulging portion (55) with the inside of the muffler (30). 4. The exhaust system of a vehicle according to claim 3, further comprising a communication passage (56). The exhaust system of a vehicle according to claim 1 or 2, wherein the sub-chamber (64) is provided outside the muffler (30). The sub-chamber (64) has a bulging portion (65) which bulges in the penetrating direction of the water draining hole (45), and a small diameter which communicates the bulging portion (65) with the outside of the muffler (30). 6. The exhaust system of a vehicle according to claim 5, further comprising a communication passage (66). The exhaust system of a vehicle according to claim 4 or 6, wherein the communication passage (56, 66) is disposed toward the vehicle body rear side of the bulging portion (55, 65). The interior of the muffler (30) is divided into a plurality of rooms (31, 32, 33) by a plurality of partition walls (41, 42),
The water draining hole (45) is provided in a chamber (31) which is most separated in the combustion gas path from the chamber (33) in which the oxygen sensor (43) is provided. The exhaust system of a vehicle according to any of the preceding claims. 9. A device according to any of the preceding claims, characterized in that the sub-chamber (54, 64) is formed by fixing a covering member (50, 60) to the shell (34) of the muffler (30). Vehicle exhaust system according to claim 1.

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