Exhaust device

Abstract

To provide an exhaust device which can maintain a temperature of a sensor at a proper temperature even if attaching the sensor to a combustion gas passage which is arranged in a muffler.SOLUTION: In an exhaust device (30) having a sensor (80) for detecting a prescribed component contained in a combustion gas (G), a boss (54) for supporting the sensor (80) is attached via a support member (53) attached to an outer shell member (47) which constitutes a passage of a combustion gas (G). The exhaust device comprises a catalyst device (42) for purifying the combustion gas (G), and the sensor (80) is arranged at a member which is connected to a downstream side of the catalyst device (42) and immediately thereafter in a flow passage of the combustion gas (G). Since the outer shell member (47) is contracted in diameter as progressing toward a downstream side of the flow passage of the combustion gas (G), the outer shell member is formed into a tapered pipe whose surface is inclined in a side face view of the sensor (80).SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an exhaust system, and more particularly to an exhaust system equipped with a sensor for detecting the concentration of a predetermined component contained in the combustion gas of an internal combustion engine. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known an exhaust system in which a sensor for detecting the concentration of a predetermined component contained in combustion gas of an internal combustion engine is disposed so that the detection portion is exposed within a passage of the combustion gas.

[0003] Patent Document 1 discloses a configuration in an exhaust system for a motorcycle, in which a cylindrical boss for supporting a cylindrical oxygen sensor is attached directly to an opening provided in a passage for combustion gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-214904 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the configuration of Patent Document 1, the boss supporting the sensor is attached directly to the combustion gas passage, so the temperature of the combustion gas passage is easily transmitted to the sensor via the boss. This creates the problem that if an attempt is made to place the sensor inside the muffler, where it is less exposed to the wind from driving, the temperature of the sensor is likely to become high.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an exhaust system which overcomes the above-mentioned problems of the conventional technology and is capable of suppressing a rise in temperature of a sensor even when the sensor is disposed inside a muffler. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a first feature of the present invention is that, in an exhaust device (30) having a sensor (80) for detecting a specific component contained in a combustion gas (G), a boss (54) for supporting the sensor (80) is attached via a support member (53) attached to an outer shell member (47) that defines a passage for the combustion gas (G).

[0008] A second feature is that the combustion gas (G) is purified by a catalytic device (42), and the sensor (80) is disposed in a member connected immediately after and downstream of the catalytic device (42) in the flow path of the combustion gas (G).

[0009] A third feature is that the outer shell member (47) is a tapered tube whose surface is inclined in a side view of the sensor (80) by decreasing in diameter toward the downstream side of the flow path of the combustion gas (G).

[0010] A fourth feature is that the exhaust device (30) is attached to the body of a saddle-type vehicle (1), the saddle-type vehicle (1) has a functional part (27) located in front of the sensor (80), and the functional part (27) covers at least a portion of the sensor (80) when viewed from the front of the vehicle body.

[0011] A fifth feature is that a wind receiving member (51) is provided around the sensor (80) and is inclined so that the rear side of the vehicle body is positioned more outward in the vehicle width direction than the front side of the vehicle body.

[0012] A sixth feature is that the sensor (80) is disposed on the inner side in the vehicle width direction of a side stand (24) attached to the body of the saddle riding type vehicle (1) in a side view of the vehicle body.

[0013] A seventh feature is that, by attaching the boss (54) via the support member (53), the boss (54) is disposed at a position spaced radially outward from the opening (48) formed in the outer shell member (47).

[0014] Furthermore, an eighth feature is that the boss (54) is attached to a first support member (52) which is attached to the support member (53). Effect of the Invention

[0015] According to the first feature, in an exhaust system (30) having a sensor (80) for detecting a specific component contained in a combustion gas (G), a boss (54) for supporting the sensor (80) is attached via a support member (53) attached to an outer shell member (47) forming a passage for the combustion gas (G), so that the temperature of the outer shell member is less likely to be transmitted to the boss and the sensor, compared to a configuration in which a boss is directly attached to the outer shell member forming the passage for the combustion gas. This makes it possible to prevent the temperature of the sensor from becoming too high, even when the sensor is disposed inside the muffler.

[0016] According to the second feature, a catalytic device (42) that purifies the combustion gas (G) is provided, and the sensor (80) is disposed in a member that is connected downstream and immediately after the catalytic device (42) in the flow path of the combustion gas (G). Therefore, by disposing the sensor immediately after the catalytic device, it is possible to improve the accuracy of detection of a specified component of the combustion gas.

[0017] According to the third feature, the outer shell member (47) is a tapered tube whose diameter decreases toward the downstream side of the flow path of the combustion gas (G) and whose surface of the sensor (80) is inclined in side view. Therefore, compared to a configuration in which the surface of the outer shell member is oriented horizontally, for example, the sensor can be disposed near the center of the outer shell member, thereby enabling space saving.

[0018] According to a fourth feature, the exhaust device (30) is attached to the body of a saddle-riding vehicle (1), the saddle-riding vehicle (1) has a functional part (27) located in front of the sensor (80), and the functional part (27) covers at least a part of the sensor (80) when viewed from the front of the vehicle body, so that it is possible to protect the sensor from stones or the like that may be thrown from the front while the saddle-riding vehicle is traveling.

[0019] According to the fifth feature, a wind-receiving member (51) is provided around the sensor (80) and is inclined so that the rear side of the vehicle body is positioned more outward in the vehicle width direction than the front side of the vehicle body. Therefore, by receiving the wind generated by the vehicle while traveling with the wind-receiving member, the cooling effect of the sensor can be further enhanced.

[0020] According to the sixth feature, the sensor (80) is disposed on the inner side in the vehicle width direction of the side stand (24) attached to the body of the saddle riding type vehicle (1) in a side view of the vehicle body, so that the sensor can be protected from stones or the like thrown from the side of the vehicle body.

[0021] According to the seventh feature, by attaching the boss (54) via the support member (53), the boss (54) is disposed at a position spaced radially outward from the opening (48) formed in the outer shell member (47). Therefore, since the boss does not come into direct contact with the opening provided in the outer shell member, heat from the outer shell member is less likely to be transferred to the sensor, and the temperature of the sensor can be prevented from becoming too high.

[0022] According to the eighth feature, since the boss (54) is attached to the first support member (52) which is attached to the support member (53), the temperature of the sensor can be further prevented from becoming too high. [Brief description of the drawings]

[0023] [Figure 1] 1 is a right side view of a motorcycle to which an exhaust device according to an embodiment of the present invention is applied. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a partially enlarged left side view of the motorcycle with exterior parts removed. [Figure 4] FIG. [Diagram 5] 4 is a cross-sectional view taken along line VV in FIG. 3. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 4. [Figure 8] FIG. 8 is a partially enlarged view of FIG. [Figure 9] 4 is a cross-sectional view showing the sensor attachment portion as viewed from the side of the sensor. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] A preferred embodiment of the present invention will be described in detail below with reference to the drawings. Fig. 1 is a right side view of a motorcycle 1 to which an exhaust device 30 according to one embodiment of the present invention is applied. Fig. 2 is a left side view of the motorcycle 1. The motorcycle 1 is a saddle-ride type vehicle that travels by transmitting the driving force of a power unit P, which is an integral configuration of an internal combustion engine and a transmission, to a rear wheel WR via a drive chain 18.

[0025] A head pipe F1 that rotatably supports a steering stem (not shown) is provided at the front end of a pair of left and right main frames F2 that constitute the body frame F. A top bridge 9 and a bottom bridge 5 that support a pair of left and right front forks 2 are fixed to the upper and lower ends, respectively, of the steering stem.

[0026] A front wheel WF is rotatably supported on the lower end of the front fork 2. A front fender 3 that covers the upper part of the front wheel WF is attached to the front fork 2. A pair of left and right steering handlebars 10 are attached to the upper part of the top bridge 9. A front cowl 6 that supports a headlight 4 is disposed in front of the head pipe F1. A windscreen 8 and a pair of left and right rearview mirrors 7 are attached to the upper part of the front cowl 6. A pair of left and right side cowls 23 are connected to the lower part of the front cowl 6, and an under cowl 22 that covers the lower part of the power unit P is connected to the lower end of the side cowl 23.

[0027] A fuel tank 11 is disposed on the upper part of the main frame F2. A pivot frame F3 supporting a pivot 21 that pivotally supports a swing arm 19 so that it can swing is connected to the rear end of the main frame F2, which extends rearward and downward from the head pipe F1. Step holders 28 supporting step bars 20 on which the rider places his / her feet are attached to positions near the bottom of the pivot frame F3. A side stand 24 that supports the vehicle body in a state inclined to the left is rotatably attached to the lower end of the pivot frame F3 on the left side in the vehicle width direction. A power unit P to which an exhaust device 30 is attached is suspended below the main frame F2 and in front of the pivot frame F3.

[0028] A swing arm 19 that rotatably supports the rear wheel WR is suspended from the main frame F2 at a position toward the front by the rear cushion 12. A rear frame F4 that extends rearward and upward and supports a seat 13 on which a rider sits and a rear cowl 15 in which a taillight unit 16 is embedded is fixed to the rear end of the main frame F2. In addition, a pair of left and right tandem step holders 14 and a rear fender 17 that covers the upper part of the rear wheel WR are attached to the rear frame F4.

[0029] The exhaust device 30 has a muffler 31 located below the step bar 20. A muffler protector 32 is attached to the right side of the muffler 31 in the vehicle width direction. A sensor attachment part 50 is provided on the left side of the muffler 31 in the vehicle width direction, to which a sensor 80 for detecting the concentration of a predetermined component contained in the combustion gas is attached. The sensor attachment part 50 is disposed at a position on the inside of the side stand 24 in the vehicle width direction, thereby making it possible to protect the sensor from stones and the like that may fly from the side of the vehicle body.

[0030] Fig. 3 is a partially enlarged left side view of the motorcycle 1 with exterior parts removed. Fig. 4 is a left side view of the exhaust device 30. The same reference numerals as those in the above sections indicate the same or equivalent parts. The exhaust device 30 is made up of four exhaust pipes 33 connected to the cylinder head 29 of the internal combustion engine, a collecting section 34 connected to the rear of the exhaust pipes 33, a catalyst storage section 35 connected to the rear of the collecting section 34, a muffler 31 connected to the rear of the catalyst collecting section 35, and an exhaust pipe 40 protruding from the rear of the muffler 31.

[0031] The sensor mounting portion 50, provided on the left side of the muffler 31 in the vehicle width direction, is composed of a wind receiving member 51 that receives wind from the front while the vehicle is traveling, and a first support member 52 that is circular when viewed from the front and faces through an opening provided in the wind receiving member 51.

[0032] A cylindrical oil filter 26 is attached to the front surface of the crankcase 25 that supports the cylinder head 29, and an oil pan 27 for storing oil is attached to the lower end of the crankcase 25. A sensor 80 for detecting the concentration of a predetermined component contained in the combustion gas G is attached to a sensor attachment portion 50 provided in the muffler 31. A harness 81 for outputting a sensor signal extends forward from the upper end of the substantially cylindrical sensor 80. The sensor 80 may be, for example, an O2 sensor or LAF sensor for detecting oxygen concentration, or a SO2 sensor for detecting nitrogen dioxide concentration.

[0033] A cylindrical catalytic converter 42 is housed in the catalyst storage section 35. An attachment hole 82 into which the sensor 80 is screwed is provided in a member connected immediately downstream of the catalytic converter 42. Inside the muffler 31, a first pipe 36 connected to the rear of the catalytic converter 42, a second pipe 37 having a punched pipe 38, and a third pipe 39 connected to the exhaust pipe 40 are arranged, and together with a number of partition walls (not shown), an expansion chamber for expanding the combustion gas G is formed.

[0034] Combustion gas G discharged from an exhaust port provided in the cylinder head 29 passes through an exhaust pipe 33, a collecting section 34, a catalyst housing section 35, the muffler 31, and an exhaust pipe 40, and is discharged to the rear of the vehicle body.

[0035] Fig. 5 is a cross-sectional view taken along line VV in Fig. 3. The same reference numerals as those mentioned above indicate the same or equivalent parts. The catalyst device 42 housed in the catalyst housing section 35 has a configuration in which a cylindrical honeycomb core 43 is housed in a cylindrical outer tube 44. The honeycomb core 43 is a metal foil made of overlapping flat and corrugated foils carrying a catalyst such as platinum, which is wound several times to form a honeycomb structure.

[0036] The catalytic converter 42 is housed in a heat insulating tube 46 that constitutes the catalyst housing 35, with a case member 45 wound around the outer side of the outer tube 44. A wind receiving member 51 made of a thin metal plate member is provided with a protruding portion 51a at its rear end toward the left side in the vehicle width direction, and is disposed at an angle so that the rear side of the vehicle body is positioned more outward in the vehicle width direction than the front side of the vehicle body. This makes it easier for the wind receiving member 51 to receive the wind generated by traveling, and improves the cooling effect of the sensor 80.

[0037] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 3. The same reference numerals as those mentioned above indicate the same or equivalent parts. The oil pan 27 attached to the lower end of the crankcase 25 is disposed with its downward protruding portion offset to the left in the vehicle width direction with respect to the center of the vehicle body. In a front view of the vehicle body, the four exhaust pipes 33 are arranged side by side along a sloping surface that slopes upward to the left in the figure on the right side of the oil pan 27 in the vehicle width direction. A collecting portion 34 connected to the rear of the exhaust pipes 33 curves to the left in the vehicle width direction behind the oil pan 27 and is connected to the front of the muffler 31.

[0038] When viewed from the front of the vehicle body, the sensor 80 is disposed at a position where it can be slightly seen from the inclined surface that slopes upward to the right in the figure on the left side in the vehicle width direction of the oil pan 27. This makes it possible to protect the sensor 80 from stones and the like flying from the front while ensuring the cooling effect of the wind caused by traveling by the wind receiving member 51.

[0039] Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 4. Fig. 8 is a partially enlarged view of Fig. 7, and Fig. 9 is a cross-sectional view showing the sensor mounting portion 50 as viewed from the side of the sensor 80. The same reference numerals as above indicate the same or equivalent parts. The sensor 80 is attached to a tapered tube 47, which serves as an outer shell member connected to the rear of the catalytic converter 42, and is disposed at a position immediately downstream of and immediately behind the catalytic converter 42. This improves the accuracy of detection of a predetermined component contained in the combustion gas G.

[0040] In this embodiment, the cylindrical boss 54 to which the sensor 80 is screwed is not directly attached to the tapered tube 47, but is attached to the first support member 52 via the second support member 53 attached to the tapered tube 47. With this configuration, the boss 54 does not directly contact the second support member 53, so that the temperature of the sensor 80 can be further prevented from becoming too high. In the axial direction of the sensor 80, the first support member 52 is fixed to the upper edge of the second support member 53, the boss 54 is attached to the first support member 52, and the wind receiving member 51 is fixed to the upper edge of the first support member 52. The periphery of the wind receiving member 51 is attached to an opening provided in the heat shield 49 that forms the outer shell of the muffler 31. Note that attaching the boss 54 via the second support member 53 is not limited to the case where the first support member 52 to which the boss 54 is attached is attached to the second support member 53 as in this embodiment, but also includes the case where the boss 54 is directly attached to the second support member 53.

[0041] In this embodiment, by attaching the boss 54 via the second support member 53, the boss 54 is disposed at a position spaced radially outward from the opening 48 formed in the tapered tube 47. As a result, the boss 54 does not come into direct contact with the edge of the opening 48 of the tapered tube 47, so that heat from the tapered tube 47 is less likely to be transmitted to the sensor 80, and a rise in temperature of the sensor 80 can be suppressed.

[0042] A connecting member 47a is attached to the upstream end of the tapered tube 47 for connecting to the outer tube 42 of the catalytic converter 42. The outer shell member is composed of the tapered tube 47 and the connecting member 47a. As shown in FIG. 9, the diameter of the tapered tube 47 decreases toward the downstream side, so that the surface of the sensor 80 is shaped to slope downward toward the rear in a side view of the sensor 80. This makes it possible to dispose the sensor 80 closer to the center of the tapered tube 47 and reduce the amount of protrusion of the sensor 80 upward in the figure, compared to a configuration in which the surface of the tapered member 47 is oriented in the horizontal direction in the figure.

[0043] As described above, according to the exhaust device 30 of the present invention, in the exhaust device 30 having the sensor 80 that detects a predetermined component contained in the combustion gas G, the boss 54 supporting the sensor 80 is attached to the first support member 52 via the second support member 53 attached to the tapered tube 47 that constitutes the passage of the combustion gas G, so that it is possible to make it difficult for the temperature of the tapered tube 47 to be transmitted to the boss 54 and the sensor 80, compared to a configuration in which the boss 54 supporting the sensor 80 is directly attached to the passage of the combustion gas G. This makes it possible to prevent the temperature of the sensor 80 from becoming too high, even when the sensor 80 is disposed inside the muffler 51.

[0044] The shape of the motorcycle, the structure of the exhaust system, the internal structure of the muffler, the shape of the oil pan, the shape and structure of the sensor, the number and arrangement of the sensors, the shape and structure of the wind receiving member and the first support member, the shape and structure of the second support member, the mounting position of the second support member, the shape and structure of the tapered tube, the shape and structure of the catalytic converter, etc. are not limited to the above-mentioned embodiments and can be modified in various ways. The exhaust system according to the present invention is not limited to motorcycles and can be applied to various vehicles such as saddle-type three-wheeled and four-wheeled vehicles, and three-wheeled and four-wheeled vehicles having a passenger compartment. [Explanation of symbols]

[0045] Reference Signs List 1...motorcycle (saddle-type vehicle), 24...side stand, 27...oil pan (functional part), 30...exhaust device, 31...muffler, 42...catalyst device, 47...outer shell member, 51...wind receiving member, 52...first support member, 53...second support member (support member), 54...boss, 80...sensor, G...combustion gas

Claims

1. In an exhaust system (30) having a sensor (80) for detecting a predetermined component contained in a combustion gas (G), The exhaust device includes a boss (54) for supporting the sensor (80) via a support member (53) attached to an outer shell member (47) that defines a passage for the combustion gas (G).

2. A catalytic converter (42) for purifying the combustion gas (G), 2. The exhaust system of claim 1, wherein the sensor (80) is disposed on a member connected immediately downstream of and to the catalytic device (42) in a flow path of the combustion gas (G).

3. 3. The exhaust device according to claim 1, wherein the outer shell member (47) is a tapered pipe whose diameter decreases toward a downstream side of the flow path of the combustion gas (G) so that the surface of the sensor (80) is inclined in a side view.

4. The exhaust device (30) is attached to a body of a saddle-type vehicle (1), The saddle-type vehicle (1) has a functional component (27) located in front of the sensor (80), The exhaust system according to claim 1 or 2, wherein the functional component (27) covers at least a portion of the sensor (80) when seen from the front of the vehicle body.

5. 5. The exhaust system according to claim 4, further comprising a wind receiving member (51) inclined so that a rear side of the vehicle body is positioned more outward in the vehicle width direction than a front side of the vehicle body, and disposed around the sensor (80).

6. 5. The exhaust system according to claim 4, wherein the sensor (80) is disposed on an inner side in a vehicle width direction of a side stand (24) attached to a body of the saddle riding type vehicle (1) when viewed from the side of the vehicle body.

7. 3. The exhaust device according to claim 1, wherein the boss is attached via the support member, so that the boss is disposed at a position spaced radially outward from an opening formed in the outer shell member.

8. 3. The exhaust system of claim 1 or 2, wherein the boss (54) is attached to a first support member (52) that is attached to the support member (53).

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