CN111902616A

CN111902616A - Exhaust muffler device

Info

Publication number: CN111902616A
Application number: CN201980022109.6A
Authority: CN
Inventors: 久保俊博; 仓泽侑史
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2018-03-27
Filing date: 2019-03-22
Publication date: 2020-11-06
Anticipated expiration: 2039-03-22
Also published as: DE112019001616T5; CN111902616B; JP6905637B2; WO2019188801A1; BR112020018984A2; JPWO2019188801A1

Abstract

The invention provides an exhaust muffler device. The exhaust muffler device (24) includes: an exhaust pipe (31) which forms a flow path of the exhaust gas and has a communication hole (45) penetrating through the pipe wall; a gas sensor (33) that is attached to the exhaust pipe (31) and detects the gas in the exhaust pipe (31); and an outer cylinder (34) attached to the exhaust pipe (31), forming a space around the exhaust pipe (31) that communicates with the communication hole (45), and having a drain hole (46) disposed at a position that does not overlap with the communication hole (45) when viewed from the bottom. Thus, even if the resonator is provided at the front of the muffler, the detection accuracy of the gas sensor can be ensured.

Description

Exhaust muffler device

Technical Field

The present invention relates to an exhaust muffler device, including: an exhaust pipe which forms a flow path of exhaust gas and has a communication hole penetrating through a pipe wall; a gas sensor mounted on the exhaust pipe for detecting gas in the exhaust pipe; and an outer cylinder attached to the exhaust pipe, and forming a space communicating with the communication hole around the exhaust pipe.

Background

Patent document 1 discloses an exhaust muffler device including a resonator at the rear of a muffler. In the resonator chamber, an opening for dewatering is formed below in the direction of gravity. Dew condensation water generated in the resonator chamber is discharged to the outside of the resonator chamber through the opening for dehydration.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-156326

Disclosure of Invention

Problems to be solved by the invention

A catalyst for purifying exhaust gas is disposed upstream of the muffler. An O2 sensor for detecting the action of the catalyst is disposed downstream of the catalyst. If the resonator is provided at the front of the muffler, outside air may enter the exhaust pipe through the water discharge hole of the resonator, and the detection accuracy of the O2 sensor may be affected.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an exhaust muffler device capable of ensuring detection accuracy of a gas sensor even if a resonator is provided at a front portion of a muffler.

Means for solving the problems

The 1 st aspect of the present invention provides an exhaust muffler device, including: an exhaust pipe which forms a flow path of exhaust gas and has a communication hole penetrating through a pipe wall; a gas sensor attached to the exhaust pipe and detecting a gas in the exhaust pipe; and an outer cylinder attached to the exhaust pipe, forming a space around the exhaust pipe to communicate with the communication hole, and having a drain hole arranged at a position not overlapping with the communication hole when viewed from above.

According to the second aspect of the invention, in the structure according to the first aspect of the invention, the gas sensor is disposed upstream of the communication hole, and a distance between the gas sensor and the drain hole is smaller than a distance between the gas sensor and the communication hole.

According to claim 3, in the configuration of claim 2, the gas sensor is disposed upstream of the outer cylinder along the exhaust pipe.

According to the 4 th aspect of the present invention, in the structure according to the 3 rd aspect, the outer cylinder has a front body formed in a conical shape having a diameter that increases from a front end along the exhaust pipe and further increases toward a downstream, and the front body is disposed rearward than footrests for receiving the feet of the rider when the front body is mounted on the saddle-ridden vehicle.

According to claim 5, in addition to the configuration of claim 4, when the gas sensor is mounted on the saddle-ride type vehicle, the gas sensor is disposed at a front side of the step.

According to the 6 th aspect, in addition to the 5 th aspect, a plurality of spaces are partitioned by 1 or more partitions in the outer cylinder, and 1 of the spaces is a resonator chamber.

According to claim 7, in the configuration of claim 6, the resonator chamber is disposed in the front body.

According to the 8 th aspect, in the 7 th aspect, the exhaust pipe penetrates the resonator chamber, and the communication hole opens to the resonator chamber.

According to the 9 th aspect, in addition to the configuration of the 8 th aspect, the exhaust muffler device further includes a catalyst disposed in the exhaust pipe upstream of the gas sensor.

According to a 10 th aspect of the present invention, in the structure according to the 9 th aspect, the plurality of communication holes are arranged at positions not overlapping with a straight line connecting center positions of the communication holes in a bottom view.

Effects of the invention

According to the aspect 1, the outside air entering from the drain hole is less likely to flow into the exhaust pipe, and the detection accuracy of the gas sensor is easily ensured. In addition, the number of members for preventing inflow of outside air can be reduced.

According to the aspect 2, since the drain hole is disposed on the upstream side of the communication hole in the exhaust gas flow direction, the inflow of the outside air can be effectively prevented by the labyrinth effect as compared with the case where the drain hole is disposed on the downstream side.

According to the aspect 3, the distance between the gas sensor and the communication hole can be secured, and inflow of outside air can be effectively prevented.

According to the aspect 4, since the outer cylinder is gradually expanded in diameter, it is possible to easily secure a space for the rider's feet and avoid interference with the outer cylinder.

According to the 5 th aspect, the space of the gas sensor can be easily secured.

According to the 6 th aspect, sound deadening can be effectively achieved based on the configuration of the resonator chamber.

According to the 7 th aspect, the resonator chamber can be arranged to avoid an increase in size of the outer cylinder.

According to the aspect 8, since the communication hole is formed in the pipe wall of the exhaust pipe and the air in the resonator chamber can be further introduced from the communication hole, the reverse flow can be prevented while the sound deadening effect is exerted.

According to the 9 th aspect, the gas sensor detects exhaust gas downstream of the catalyst, so the gas sensor can detect deterioration of the catalyst

According to the 10 th aspect, the drain hole is offset not only in the front-rear direction but also in the left-right direction with respect to the communication hole, and therefore, the inflow of the outside air into the exhaust pipe can be more reliably prevented.

Drawings

Fig. 1 is a side view schematically showing the entire configuration of a motorcycle as one specific example of a saddle-ride type vehicle.

Fig. 2 is an enlarged side view schematically showing the entire configuration of the exhaust muffler device.

Fig. 3 is an enlarged bottom view of the outer cylinder schematically showing the configuration of the resonator chamber.

Fig. 4 is an enlarged side view of the outer cylinder schematically showing the configuration of the resonator chamber according to another embodiment.

Fig. 5 is an enlarged side view of the outer cylinder schematically showing the structure of the resonator chamber according to another embodiment, corresponding to fig. 3.

Fig. 6 is an enlarged side view schematically showing the entire structure of the exhaust muffler device according to another embodiment, corresponding to fig. 2.

Description of the reference numerals

11 … straddle type vehicle (two-wheel motorcycle)

31 … exhaust pipe

32 … catalyst

33 … gas sensor (O2 sensor)

34 … external cylinder

34a … precursor

36 … foot pedal

37 … No. 1 baffle

38 … resonator chamber

39 … No. 2 baffle

42 … No. 3 baffle

45 … communication hole

46 … drainage hole

L1 … distance (sensor to drain hole)

L2 … distance (of sensor and communication hole)

Detailed Description

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Here, the upper, lower, front, rear, left, and right of the vehicle body are defined based on the line of sight of a rider riding on the motorcycle.

Fig. 1 schematically shows an overall configuration of a motorcycle according to an embodiment of the present invention. The motorcycle 11 includes a body frame 12. At the front end of the vehicle body frame 12, a front fork 14 is supported by the head pipe 13 so as to be steerable. The front wheel WF is supported by the front fork 14 so as to be rotatable about the axle 15. A handle 16 is coupled to the front fork 14 on the upper side of the head pipe 13. On the rear side of the vehicle body frame 12, a swing arm 18 is supported by the pivot frame 17 so as to be swingable about a support shaft 19 extending horizontally in the vehicle width direction. The rear wheel WR is supported at the rear end of the swing arm 18 so as to be rotatable about the axle 21.

The internal combustion engine 23 is mounted on the vehicle body frame 12 between the front wheels WF and the rear wheels WR. The internal combustion engine 23 generates power about the rotation axis Rx. The power of the internal combustion engine 23 is transmitted to the rear wheel WR via the power transmission device. In the present specification, description of the same structure as that of a known internal combustion engine may be omitted.

An exhaust muffler device 24 is connected to the internal combustion engine 23, and the exhaust muffler device 24 discharges the exhaust gas of the internal combustion engine 23 to the rear of the vehicle body while exhibiting a purifying function and a silencing function. The exhaust muffler device 24 includes: an exhaust pipe unit 25 connected to an exhaust path of the internal combustion engine 23 at an upstream end thereof and extending rearward through a lower portion of the internal combustion engine 23; and a muffler unit 26 connected to the downstream end of the exhaust pipe unit 25 below the swing arm 18 in front of the rear wheel WR, and having an exhaust port arranged at a position higher than the axle 21 and lateral to the rear wheel WR. The muffler unit 26 performs a sound deadening function of the internal combustion engine 23. The exhaust gas of the internal combustion engine 23 is discharged rearward from the exhaust port of the muffler unit 26.

A fuel tank 27 for storing fuel is mounted on the vehicle body frame 12 above the internal combustion engine 23. A passenger seat 28 is mounted on the vehicle body frame 12 behind the fuel tank 27. Fuel is supplied from the fuel tank 27 to a fuel injection device (not shown) of the internal combustion engine 23. When driving the motorcycle 11, the occupant sits astride the occupant seat 28.

As shown in fig. 2, the exhaust pipe unit 25 includes: an exhaust pipe 31 forming a flow path of exhaust gas; a catalyst 32 that is incorporated into the exhaust pipe 31 in a descending region descending from the internal combustion engine 23 and purifies exhaust gas; and an O2 sensor 33 attached to the exhaust pipe 31 at the tip of a horizontal region extending continuously in the horizontal direction from the descending region downstream, and detecting the oxygen concentration in the exhaust pipe 31. Based on the oxygen concentration detected by the O2 sensor 33, deterioration of the catalyst 32 can be determined.

An outer cylinder 34 is connected to the exhaust pipe 31, and the outer cylinder 34 forms a space around the exhaust pipe 31 in a rear upper region extending continuously rearward and upward from the horizontal region downstream. The outer cylinder 34 has: a front body 34a formed in a conical shape, which expands in diameter from the leading end along the exhaust pipe 31 and as it goes downstream; and a cylinder 34b that is coupled to the rear end of the precursor 34a to form a space continuous with the space in the precursor 34 a.

Brackets

35a, 35b for connecting the outer cylinder 34 to the vehicle body frame 12 are fixed to the front body 34a and the cylinder 34b, respectively. For example, welding is used for fixing. The front body 34a is formed from a single tube, so the bracket 35a can be simply welded. As shown in fig. 1, the front body 34a of the outer cylinder 34 is disposed rearward of the steps 36 for carrying the rider's feet, and the O2 sensor 33 is disposed forward of the steps 36. The O2 sensor 33 is disposed upstream of the outer cylinder 34 along the exhaust pipe 31.

The front body 34a is fixed at the front end around the exhaust pipe 31, and a 1 st partition plate 37 is disposed in the front body 34a at a position away from the front end toward the downstream. The 1 st partition 37 partitions a resonator chamber 38 in the front body 34 a. The exhaust pipe 31 penetrates the resonator chamber 38. A 2 nd partition plate 39 is disposed at a position separated from the distal end of the cylindrical body 34b in the cylindrical body 34 b. The 2 nd partition plate 39 partitions an expansion chamber 41 with the 1 st partition plate 37. The exhaust pipe 31 passes through the 1 st partition plate 37 and opens into the expansion chamber 41. Since the expansion chamber 41 is formed by the double pipe, the number of components of the exhaust muffler device 24 is reduced.

A 3 rd partition plate 42 is assembled in the cylinder 34b at the rear end of the cylinder 34 b. The 3 rd partition plate 42 partitions between itself and the 2 nd partition plate 39 to form an auxiliary expansion chamber 43 communicating with the expansion chamber 41. A gap for communicating the auxiliary expansion chamber 43 and the expansion chamber 41 is formed between the 2 nd partition plate 39 and the cylindrical body 34b of the outer cylinder 34. A discharge pipe 44 for connecting the outside air to the expansion chamber 41 is supported by the 2 nd partition 39 and the 3 rd partition 42.

In the resonator chamber 38, a plurality of communication holes 45 penetrating the pipe wall are formed in the exhaust pipe 31. Here, a total of 3 pairs of communication holes 45 are arranged in a pair above and below. The communication hole 45 communicates the circulation path in the exhaust pipe 31 and the resonator chamber 38 with each other. The exhaust gas is caused to flow in and out of the exhaust pipe 31 through the communication hole 45, whereby resonance is generated to realize sound attenuation. The O2 sensor 33 is disposed upstream of the communication hole 45.

In the front body 34a of the outer cylinder 34, the water discharge hole 46 is arranged at a position not overlapping the communication hole 45 in a bottom view from a viewpoint located at infinity in the gravitational direction. The distance L1 between the O2 sensor 33 and the water drain hole 46 is smaller than the distance L2 between the O2 sensor 33 and the communication hole 45. As shown in fig. 3, the communication holes 45 are arranged at equal intervals along a straight line 47 connecting the center positions of the communication holes 45, and the drain holes 46 are separated from the uppermost-stream communication hole 45 at an interval Dw equal to or greater than the interval Dc of the communication holes 45 in a bottom view.

Next, the operation of the present embodiment will be described. In the exhaust muffler device 24 of the present embodiment, the outer cylinder 34 forms the resonator chamber 38 communicating with the communication hole 45 of the exhaust pipe 31 around the exhaust pipe, and the water discharge hole 46 is disposed at a position not overlapping with the communication hole 45 in a bottom view. Therefore, the outside air entering through the water drain hole 46 is less likely to flow into the exhaust pipe 31, and the detection accuracy of the O2 sensor 33 is easily ensured. In addition, the number of members for preventing inflow of outside air can be reduced.

In the present embodiment, the O2 sensor 33 is disposed on the upstream side of the communication hole 45, and the distance L1 between the O2 sensor 33 and the water drain hole 46 is smaller than the distance L2 between the O2 sensor 33 and the communication hole 45. As described above, since the drain hole 46 is disposed on the upstream side of the communication hole 45 in the exhaust gas flow direction, the inflow of the outside air can be effectively prevented by the labyrinth effect as compared with the case where the drain hole 46 is disposed on the downstream side.

The O2 sensor 33 is disposed upstream of the outer cylinder 34 along the exhaust pipe 31. The distance L2 between the O2 sensor 33 and the communication hole 45 can be ensured, and inflow of outside air can be effectively prevented.

The outer cylinder 34 has a front body 34a formed in a conical shape having a diameter that increases from the front end along the exhaust pipe 31 and toward the downstream, and the front body 34a is disposed rearward of the steps 36 for receiving the rider's feet when the exhaust muffler device 24 is mounted on the motorcycle 11. Since the outer cylinder 34 is gradually expanded in diameter, a space for the rider's feet can be easily secured to avoid interference with the outer cylinder 34.

The O2 sensor 33 is disposed at the front of the pedal 36 when the exhaust muffler device 24 is mounted on the motorcycle 11. It is easy to secure the space of the O2 sensor 33.

In the outer cylinder 34, a plurality of spaces are partitioned by 1 or

more partition plates

37, 39, 42, and 1 of the spaces is a resonator chamber 38. Sound attenuation is effectively achieved based on the configuration of the resonator chamber 38.

In the exhaust muffler device 24 of the present embodiment, the resonator chamber 38 is disposed in the front body 34 a. With this arrangement, the resonator chamber 38 can be arranged to avoid an increase in size of the outer cylinder 34.

The exhaust pipe 31 penetrates the resonator chamber 38, and the communication hole 45 opens into the resonator chamber 38. The communicating hole 45 is formed in the pipe wall of the exhaust pipe 31, and the air in the resonator chamber 38 is further introduced from the communicating hole 45, so that the reverse flow can be prevented while the noise reduction effect is exerted.

The exhaust muffler device 24 of the present embodiment includes a catalyst 32 disposed in an exhaust pipe 31 upstream of an O2 sensor 33. The O2 sensor 33 detects the oxygen concentration downstream of the catalyst 32, so the O2 sensor 33 can detect degradation of the catalyst 32.

As shown in fig. 4, the lower communication hole 45 may be omitted in the above embodiment. The drain hole 46 is disposed at a position not overlapping with the straight line 47 connecting the center positions of the communication holes 45 in a bottom view, and the distance between the drain hole 46 and the communication holes 45 is further increased, so that the inflow of the outside air into the exhaust pipe 31 can be more reliably prevented. As shown in fig. 5, the communication hole 45 may be opened in the left-right direction perpendicular to the gravitational direction and may be disposed at a position offset from the drain hole 46 around the axis of the exhaust pipe 31. Since the drain hole 46 is disposed sufficiently apart from the virtual plane including the center position of the communication hole 45 in the circumferential direction of the exhaust pipe 31, the inflow of the outside air into the exhaust pipe 31 can be prevented satisfactorily. As shown in fig. 6, the O2 sensor 33 may be attached to the exhaust pipe 31 directly in front of the outer cylinder 34.

Claims

1. An exhaust muffler device, comprising:

an exhaust pipe (31) which forms a flow path of the exhaust gas and has a communication hole (45) penetrating through the pipe wall;

a gas sensor (33) attached to the exhaust pipe (31) and detecting a gas in the exhaust pipe (31); and

and an outer cylinder (34) attached to the exhaust pipe (31), wherein a space communicating with the communication hole (45) is formed around the exhaust pipe (31), and a drain hole (46) is disposed at a position not overlapping with the communication hole (45) in a bottom view.

2. The exhaust muffler device according to claim 1,

the gas sensor (33) is disposed upstream of the communication hole (45), and the distance (L1) between the gas sensor (33) and the drain hole (46) is smaller than the distance (L2) between the gas sensor (33) and the communication hole (45).

3. The exhaust muffler device according to claim 2,

the gas sensor (33) is disposed on the upstream side of the outer cylinder (34) along the exhaust pipe (31).

4. The exhaust muffler device according to claim 3,

the outer cylinder (34) has a front body (34a) formed in a conical shape that expands in diameter from the front end along the exhaust pipe (31) and that proceeds downstream, and the front body (34a) is disposed rearward of a step (36) for receiving the feet of a rider when mounted on the saddle-ridden vehicle (11).

5. The exhaust muffler device according to claim 4,

when mounted on a saddle-ride type vehicle (11), the gas sensor (33) is disposed at the front of the pedals (36).

6. The exhaust muffler device according to claim 5,

in the outer cylinder (34), a plurality of spaces are partitioned by 1 or more partition plates (37, 39, 42), and 1 of the spaces is a resonator chamber (38).

7. The exhaust muffler device according to claim 6,

the resonator chamber (38) is disposed within the precursor (34 a).

8. The exhaust muffler device according to claim 7,

the exhaust pipe (31) penetrates the resonator chamber (38), and the communication hole (45) opens in the resonator chamber (38).

9. The exhaust muffler device according to claim 8,

a catalyst (32) disposed in the exhaust pipe (31) is further provided upstream of the gas sensor (33).

10. The exhaust muffler device according to claim 9,

the plurality of communication holes (45) are arranged at positions where the drainage holes (46) do not overlap with a straight line (47) connecting the center positions of the communication holes (45) when viewed from the bottom.