Exhaust device

Abstract

Provided is an exhaust device capable of avoiding thermal influence on an exhaust sensor disposed in a space between two catalytic devices housed in an exhaust pipe. In an exhaust device (30) having an exhaust pipe (32) that houses a plurality of catalytic devices (C) that purify exhaust (G) of a power unit (P) of a vehicle (1), the exhaust pipe (32) includes a front-side exhaust pipe (32a) and a rear-side exhaust pipe (32c) that are separate from each other; and a connection portion (80) that connects the front-side exhaust pipe (32a) and the rear-side exhaust pipe (32c) to each other using a connection pipe (32b) that covers outer peripheral portions of the front-side exhaust pipe (32a) and the rear-side exhaust pipe (32c) at the same time, the front-side exhaust pipe (32a) and the rear-side exhaust pipe (32c) each housing the catalytic device (C), and an exhaust sensor (40) that detects components of the exhaust (G) is installed at the connection portion (80).

Description

Technical Field

[0001] This invention relates to exhaust devices, and more particularly to an exhaust device in which a catalytic converter is housed inside an exhaust pipe and an exhaust sensor is installed in the exhaust pipe. Background Technology

[0002] Previously, exhaust devices for purifying and silencing exhaust from internal combustion engines had the following structure: a catalytic converter was housed inside the exhaust pipe, and an exhaust sensor for detecting the composition of the exhaust was installed in a mounting hole located in the exhaust pipe.

[0003] Patent document 1 discloses an exhaust device in which an upstream catalytic converter and a downstream catalytic converter are housed inside the exhaust pipe, and an exhaust sensor is installed between the two catalytic converters.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-214904 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] However, the space sandwiched between two catalytic converters is susceptible to thermal effects from the catalytic converters, which become hot due to exhaust. There is still room for research in the construction of exhaust systems that can avoid the elongation of the exhaust pipe caused by heat and its impact on exhaust sensors.

[0009] The purpose of this invention is to solve the technical problems of the prior art and provide an exhaust device that can avoid the thermal impact on the exhaust sensor disposed in the space between two catalytic converters housed in the exhaust pipe.

[0010] Technical solutions for solving technical problems

[0011] To achieve the above objective, the exhaust device (30) of the present invention has an exhaust pipe (32) that houses multiple catalytic converters (C) for purifying the exhaust gas (G) of the power unit (P) of the vehicle (1). Its first feature is that the exhaust pipe (32) includes: a front exhaust pipe (32a) and a rear exhaust pipe (32c) that are separate from each other; a connecting part (80) that connects the front exhaust pipe (32a) and the rear exhaust pipe (32c) to each other by a connecting pipe (32b) that covers the outer periphery of both the front exhaust pipe (32a) and the rear exhaust pipe (32c), wherein the catalytic converters (C) are housed in the front exhaust pipe (32a) and the rear exhaust pipe (32c), and an exhaust sensor (40) for detecting the composition of the exhaust gas (G) is installed in the connecting part (80).

[0012] In addition, the second feature is that a cylindrical collar (60, 61, 62) is installed at the end of the catalytic device (C) inside the connecting pipe (32b).

[0013] Furthermore, a third feature is that at least one of the catalytic converter (C) housed in the front exhaust pipe (32a) and the catalytic converter (C) housed in the rear exhaust pipe (32c) has a space (71, 72) as a gap between itself and the connecting pipe (32b).

[0014] In addition, the fourth feature is that a protective component (37) is provided in front of the exhaust sensor (40) to protect the exhaust sensor (40), and the wiring harness (41) connected to the exhaust sensor (40) is located above the straight line (L) connecting the lowest point (A) of the front wheel (WF) to the lower part of the protective component (37) when the vehicle (1) is viewed from the side.

[0015] Furthermore, the fifth feature is that the collars (60, 61, 62) are mounted on the front end of the catalytic converter (C) housed in the rear exhaust pipe (32c).

[0016] In addition, the sixth feature is that one end of the collar (60, 61, 62) is formed into a gradually expanding diameter shape.

[0017] In addition, the seventh feature is that one end of the collar (60, 61, 62) is formed into a gradually narrowing shape.

[0018] Invention Effects

[0019] According to the first feature, in an exhaust device (30) having an exhaust pipe (32) that houses multiple catalytic converters (C) for the exhaust gas (G) of a power unit (P) for purifying a vehicle (1), the exhaust pipe (32) includes: a front exhaust pipe (32a) and a rear exhaust pipe (32c) that are separate from each other; a connecting part (80) that connects the front exhaust pipe (32a) and the rear exhaust pipe (32c) to each other by a connecting pipe (32b) that simultaneously covers the outer periphery of the front exhaust pipe (32a) and the rear exhaust pipe (32c), wherein the catalytic converters (C) are housed in the front exhaust pipe (32a) and the rear exhaust pipe (32c), and an exhaust gas sensor (40) for detecting the composition of the exhaust gas (G) is installed in the connecting part (80). Therefore, by connecting the front exhaust pipe and the rear exhaust pipe through the connecting pipe, it is possible to suppress the situation where the exhaust pipe elongates due to the heat of the catalytic converter. In addition, it can reduce the impact of the heat from the catalytic converter on the exhaust sensor.

[0020] According to the second feature, a cylindrical collar (60, 61, 62) is installed at the end of the catalytic converter (C) inside the connecting pipe (32b). Therefore, adjusting the exhaust flow through the collar can improve the detection accuracy of the exhaust sensor. In addition, adjusting the exhaust flow can also adjust the output of the power unit.

[0021] According to the third feature, at least one of the catalytic converter (C) housed in the front exhaust pipe (32a) and the catalytic converter (C) housed in the rear exhaust pipe (32c) has a space (71, 72) as a gap between it and the connecting pipe (32b) provided on its radially outer side. Therefore, by using the space to stir the exhaust, the detection accuracy of the exhaust sensor can be improved.

[0022] According to the fourth feature, a protective component (37) is provided in front of the exhaust sensor (40) to protect the exhaust sensor (40). The wiring harness (41) connected to the exhaust sensor (40) is located above the straight line (L) connecting the lowest point (A) of the front wheel (WF) to the lower part of the protective component (37) when viewed from the side of the vehicle body (1). Therefore, the wiring harness of the exhaust sensor can be protected from the influence of stones and other objects kicked up by the front wheel during vehicle operation.

[0023] According to the fifth feature, the collars (60, 61, 62) are installed at the front end of the catalytic converter (C) housed in the rear exhaust pipe (32c), thus enabling adjustment of exhaust flow downstream of the exhaust sensor.

[0024] According to the sixth feature, one end of the collar (60, 61, 62) is formed into a gradually expanding shape, thus allowing for arbitrary adjustment of the exhaust flow.

[0025] According to the seventh feature, one end of the collar (60, 61, 62) is formed into a gradually narrowing shape, so that the flow of exhaust gas can be adjusted arbitrarily. Attached Figure Description

[0026] Figure 1 This is a right-side view of a motorized two-wheeled vehicle that uses an exhaust device according to an embodiment of the present invention.

[0027] Figure 2 This is a magnified left-side view of a motorized two-wheeled vehicle.

[0028] Figure 3 It is a three-dimensional diagram showing the exhaust device and its surrounding structure.

[0029] Figure 4 This is a right-side view showing the exhaust system and its surrounding structure.

[0030] Figure 5 It is a cross-sectional view showing the exhaust device and its surrounding structure.

[0031] Figure 6 yes Figure 4 Sectional view along line IV-IV.

[0032] Figure 7 It is a cross-sectional view showing the structure of the connecting part.

[0033] Figure 8 This is a cross-sectional view showing the shape of the collar in a modified embodiment of this invention.

[0034] Figure 9 This is a cross-sectional view showing the shape of the collar in the second variation of this embodiment. Detailed Implementation

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 This is a right-side view of a motorized two-wheeled vehicle 1 that utilizes the exhaust device 30 according to an embodiment of the present invention. Additionally, Figure 2 This is a partially enlarged left-side view of the motorized two-wheeled vehicle 1. The motorized two-wheeled vehicle 1 is a straddle-type vehicle that transmits the driving force of a power unit P, which is integrally composed of an internal combustion engine and a transmission, to the rear wheel WR via a drive chain 17.

[0036] A head tube F1, which provides a rotatable axle support for a steering column (not shown), is provided at the front end of the pair of main frames F2 that constitute the vehicle frame F. An upper connecting plate 22 and a lower connecting plate 23, which support the pair of front forks 2, are respectively fixed at the upper and lower ends of the steering column.

[0037] The front wheel WF is rotatably supported by an axle at the lower end of the front fork 2. A front fender 3 is mounted on the front fork 2, covering the front wheel WF. A steering handle 21 supporting a pair of left and right rearview mirrors 8 is fixed on the upper part of the upper connecting plate 22. A front cover 5 supporting the headlight 4 and an instrument panel 6 are arranged in front of the upper connecting plate 22, and a pair of left and right front flashers 7 are arranged on the sides of the upper connecting plate 22.

[0038] A fuel tank 9 is mounted on the upper part of the main frame F2, and a seat 10 is mounted behind the fuel tank 9. A pivot frame F3 is fixed at a lower position on the main frame F2, which extends rearward and downward from the head tube F1. The pivot frame F3 supports the pivot 18, which pivotally supports the swing arm 16. A pair of upper rear frames F4 and lower rear frames F5 are connected to the rear of the main frame F2.

[0039] A pair of footrests 19 for the driver are mounted on the pivot frame F3. A brake pedal 23 is located near the right footrest 19 in the vehicle width direction, and a shift pedal 38 is located near the left footrest 19 in the vehicle width direction. A power unit P, equipped with an exhaust system 30, is suspended below the main frame F2 and in front of the pivot frame F3. The front of the power unit P is supported by an engine mount 22, and a radiator 20 is located above and in front of the engine mount 22.

[0040] The swing arm 16, which allows the rear wheel WR to rotate freely and is supported by the axle, is suspended from the upper rear frame F4 by a pair of left and right rear shock absorbers 15 at its rear position. An armrest 11 is provided behind the seat 10, and a taillight assembly 13 and a pair of left and right rear flashing lights 14 are supported on the rear fender 12 that covers the rear wheel WR.

[0041] The exhaust system 30 includes: a cylinder connecting pipe 31 connected to the power unit P; an exhaust pipe 32 connected to the rear of the cylinder connecting pipe 31; an ascender pipe 33 connected to the rear of the exhaust pipe 32 and extending upwards; and a muffler 34 connected to the rear of the ascender pipe 33. A muffler cover 34 is installed on the upper part of the muffler 34.

[0042] An exhaust sensor 40 for detecting the composition of exhaust gas from the power unit P is installed slightly forward of the center of the exhaust pipe 32. A wiring harness 41 transmitting the sensor signal extends from one end of the exhaust sensor 40 toward the vehicle body. A plate-shaped protective member 37 is provided in front of the exhaust sensor 40 to protect it. A second exhaust sensor 42 (see reference) is provided at the front end of the exhaust pipe 32. Figure 3 , Figure 5 A plate-shaped second protective component 36. A support bracket 38 for supporting the exhaust pipe 32 to the vehicle body is installed on the upper part of the exhaust pipe 32.

[0043] In this embodiment, the exhaust device 30 is configured such that the wiring harness 41 connected to the exhaust sensor 40 is positioned above, when viewed from the side of the motorized two-wheeled vehicle 1, the straight line L connecting the lowest point A of the front wheel WR to the lower part of the protective member 37. This protects the wiring harness 41 from stones or other objects kicked up by the front wheel WF during the movement of the motorized two-wheeled vehicle 1.

[0044] Figure 3 This is a perspective view showing the exhaust device 30 and its surrounding structure. The same reference numerals as described above denote the same or equivalent parts. A catalytic converter C (see reference numeral) housed within the exhaust pipe 32 is provided therein. Figure 4 , Figure 5 Multiple recesses 39 are held in designated positions. The exhaust sensor 40 is mounted on the left side of the exhaust pipe 32 in the vehicle width direction, slightly above the central axis of the exhaust pipe 32. The wiring harness 50 connected to the second exhaust sensor 42 is routed upwards towards the vehicle body.

[0045] Figure 4 This is a right-side view showing the exhaust device 30 and its surrounding structure. Additionally, Figure 5 This is a cross-sectional view showing the exhaust device 30 and its surrounding structure. Figure 6 yes Figure 4 The diagram shows a cross-sectional view along line IV-IV. The same reference numerals as described above denote the same or equivalent parts. Two catalytic converters C are housed in the exhaust pipe 32, one upstream and one downstream. The exhaust pipe 32 consists of a front exhaust pipe 32a, a rear exhaust pipe 32c, and a connecting pipe 32b connecting the front exhaust pipe 32a and the rear exhaust pipe 32c. The catalytic converters C are housed in the front exhaust pipe 32a and the rear exhaust pipe 32c, respectively.

[0046] The connecting pipe 32b forms a connecting portion 80, which covers the outer periphery of both the front exhaust pipe 32a and the rear exhaust pipe 32c, connecting them together. A feature of this embodiment is that an exhaust sensor 40 is installed in this connecting portion 80. Therefore, by connecting the front exhaust pipe 32a and the rear exhaust pipe 32c using the connecting pipe 32b, the thermal effects caused by the elongation of the exhaust pipes due to the heat of the catalytic converter C can be suppressed, and the impact of the heat of the catalytic converter C on the exhaust sensor 40 can be reduced.

[0047] Reference Figure 6 The recess 39 is provided to hold the catalytic converter C in a predetermined position after it has been housed in the exhaust pipe 32. Specifically, the catalytic converter C is held in the predetermined position by being pressed against the inner wall surface of the exhaust pipe 32 by the recessed portion. Therefore, special structures and components for holding the catalytic converter C in the predetermined position are not required, thus reducing production costs.

[0048] Figure 7 This is a cross-sectional view showing the structure of the connecting portion 80. The exhaust sensor 40 is mounted to the exhaust pipe 32 by screwing it into the boss 45 welded to the connecting pipe 32b. A feature of this embodiment is that, in the connecting portion 80, a first space portion 71, serving as a gap, is provided between the radially outer side of the catalytic converter C housed in the front exhaust pipe 32a and the connecting pipe 32b, and a second space portion 72, also serving as a gap, is provided between the radially outer side of the catalytic converter C housed in the rear exhaust pipe 32c and the connecting pipe 32b. Thus, by agitating the exhaust gas G using the first space portion 71 and the second space portion 72, the detection accuracy of the exhaust sensor 40 can be improved. The shape and arrangement of the first space portion 71 and the second space portion 72 can be varied, and it is also possible to configure only one of them.

[0049] Furthermore, in this embodiment, a cylindrical collar 60 is installed inside the connecting pipe 32b at the front end of the catalytic converter C housed in the rear exhaust pipe 32c. This allows for adjustment of the exhaust gas G flow using the collar 60, improving the detection accuracy of the exhaust sensor 40. Additionally, adjusting the exhaust gas G flow also allows for adjustment of the power unit P's output. It should be noted that the collar 60 can be installed not only at the front end of the downstream catalytic converter C, but also at the rear end of the upstream catalytic converter C, or at both the upstream and downstream catalytic converters C.

[0050] Figure 8 This is a cross-sectional view showing the shape of the collar 61 in a modified example of this embodiment. The collar 61 is formed with a shape that gradually increases in diameter as it moves upstream toward the flow path direction of the exhaust gas G. As a result, the flow of the exhaust gas G can be arbitrarily adjusted downstream of the exhaust gas sensor 40.

[0051] Figure 9 This is a cross-sectional view showing the shape of the collar 62 in the second variation of this embodiment. The collar 62 is formed with a shape that gradually narrows in diameter as it moves upstream toward the flow path direction of the exhaust gas G. As a result, the flow of the exhaust gas G can be arbitrarily adjusted downstream of the exhaust gas sensor 40.

[0052] As described above, according to the exhaust device 30 of the present invention, the exhaust pipe 32 includes a front exhaust pipe 32a and a rear exhaust pipe 32c that are separate from each other, and a connecting portion 80 that connects the front exhaust pipe 32a and the rear exhaust pipe 32c by a connecting pipe 32b that covers the outer periphery of both the front exhaust pipe 32a and the rear exhaust pipe 32c. A catalytic converter C is housed in both the front exhaust pipe 32a and the rear exhaust pipe 32c, and an exhaust sensor 40 is mounted in the connecting portion 80. Therefore, it is possible to suppress the elongation of the exhaust pipe 32 due to the heat of the catalytic converter C. Furthermore, it is possible to reduce the impact of the heat of the catalytic converter C on the exhaust sensor 40.

[0053] The form of the motorized two-wheeled vehicle, the number of cylinders in the internal combustion engine, the shape and structure of the exhaust system, the material and shape of the exhaust pipe, the spacing between the front and rear exhaust pipes, the shape of the connecting pipe, the shape and capacity of the space, and the shape and structure of the catalytic converter and exhaust sensor are not limited to the above-described embodiments and can be modified in various ways. The exhaust system of the present invention is not limited to motorized two-wheeled vehicles and can be applied to various vehicles such as three-wheeled vehicles and four-wheeled vehicles that use a power unit including an internal combustion engine as a drive source.

[0054] Explanation of reference numerals in the attached figures

[0055] 1: Motorized two-wheeled vehicle; 30: Exhaust system; 32: Exhaust pipe; 32a: Front exhaust pipe; 32b: Connecting pipe; 32c: Rear exhaust pipe; 37: Protective component; 40: Exhaust sensor; 41: Wiring harness; 60, 61, 62: Collar; 71: First space section (space section); 72: Second space section (space section); 80: Connecting part; P: Power unit; G: Exhaust; C: Catalytic converter; A: Lowest point of the front wheel; L: Straight line.

Claims

1. An exhaust device (30) having an exhaust pipe (32) for housing multiple catalytic converters (C) for purifying the exhaust gas (G) of a power unit (P) of a vehicle (1), characterized in that, The exhaust pipe (32) includes: a front exhaust pipe (32a) and a rear exhaust pipe (32c) that are separate from each other; and a connecting part (80) that connects the front exhaust pipe (32a) and the rear exhaust pipe (32c) to each other by means of a connecting pipe (32b) that covers the outer periphery of both the front exhaust pipe (32a) and the rear exhaust pipe (32c). The catalytic converter (C) is housed in the front exhaust pipe (32a) and the rear exhaust pipe (32c). An exhaust sensor (40) for detecting the composition of the exhaust gas (G) is installed at the connection part (80).

2. The exhaust device according to claim 1, characterized in that, A cylindrical collar (60, 61, 62) is installed at the end of the catalytic device (C) inside the connecting pipe (32b).

3. The exhaust device according to claim 1 or 2, characterized in that, At least one of the catalytic converter (C) housed in the front exhaust pipe (32a) and the catalytic converter (C) housed in the rear exhaust pipe (32c) has a space (71, 72) that serves as a gap between it and the connecting pipe (32b).

4. The exhaust device according to claim 1 or 2, characterized in that, A protective component (37) is provided in front of the exhaust sensor (40) to protect the exhaust sensor (40). The wiring harness (41) connected to the exhaust sensor (40) is positioned above the straight line (L) connecting the lowest point (A) of the front wheel (WF) to the lower part of the protective component (37) when viewed from the side of the vehicle (1).

5. The exhaust device according to claim 2, characterized in that, The collars (60, 61, 62) are installed at the front end of the catalytic converter (C) housed in the rear exhaust pipe (32c).

6. The exhaust device according to claim 2, characterized in that, One end of the collar (60, 61, 62) is formed into a gradually expanding diameter shape.

7. The exhaust device according to claim 2, characterized in that, One end of the collar (60, 61, 62) is formed into a gradually narrowing shape.

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