JP6866732B2 - Exhaust system for saddle-mounted vehicles - Google Patents

Description

The present invention relates to an exhaust device for a saddle-mounted vehicle provided with a catalyst device.

In the exhaust system of a saddle-mounted vehicle equipped with a 4-cycle engine, a chamber is known in which a chamber is provided between an exhaust pipe and a muffler. According to this configuration, the chamber can be provided with sound deadening performance by increasing the volume of the chamber. Therefore, the muffler can be miniaturized.

In addition, with the recent tightening of exhaust gas regulations, it is required to improve the exhaust gas purification performance of the exhaust system. Some saddle-mounted vehicles have a configuration in which a plurality of catalyst devices are housed in a chamber. By using a plurality of catalyst devices, the exhaust gas purification performance of the exhaust system can be improved. Further, by accommodating each catalyst device in the chamber, the degree of freedom of piping of the exhaust pipe can be increased.

Patent Document 1 below describes an exhaust device in which a plurality of catalyst devices are housed in a chamber.

Japanese Unexamined Patent Publication No. 2010-270702

However, by accommodating a plurality of catalyst devices in the chamber, the space in which the exhaust noise reduction effect is exerted becomes smaller in the chamber. As a result, the muffling performance of the chamber deteriorates. Therefore, it is necessary to increase the size of the muffler in order to enhance the effect of reducing the exhaust noise caused by the muffler. When the muffler becomes large, it becomes difficult to secure the bank angle and weight balance of the saddle-mounted vehicle, or it becomes difficult to improve the appearance.

In the exhaust device described in Patent Document 1, as shown in FIG. 8 of the document, the remaining space in the chamber accommodating portion after accommodating the first catalyst and the second catalyst in the chamber accommodating portion is small. Moreover, the remaining space is divided by the second catalyst. Therefore, it is considered that the effect of reducing the exhaust noise obtained by the residual space is low.

On the other hand, in order to improve the exhaust gas purification performance of the exhaust system, it is required to activate the catalyst at an early stage when the engine is started. Most of the exhaust systems in saddle-type vehicles employ a method of rapidly raising the temperature of the catalyst by applying high-temperature exhaust gas to the catalyst to activate the catalyst at an early stage. When such a method is adopted in a configuration including a plurality of catalyst devices, it is necessary to efficiently and evenly apply exhaust gas to each of the plurality of catalysts. However, it is not easy to realize a configuration in which exhaust gas is efficiently and evenly applied to each of a plurality of catalysts without complicating the structure of the exhaust system.

In the exhaust device described in Patent Document 1, as shown in FIG. 5 of the document, a path for directly reaching the first catalyst is formed by the exhaust pipe, and the exhaust directly reaches the second catalyst. The path to be made is formed by a bypass passage connected in the middle of the exhaust pipe. As described above, in the exhaust device described in Patent Document 1, the structure of the exhaust pipe is complicated because the exhaust is applied to each of the plurality of catalysts.

The present invention has been made in view of the above-mentioned problems, for example, and the subject of the present invention is to improve the sound deadening performance of the chamber and to improve the structure while having a configuration in which a plurality of catalyst devices are housed in the chamber. An object of the present invention is to provide an exhaust device for a saddle-type vehicle capable of early activation of a catalyst without complication.

In order to solve the above problems, the exhaust device of the saddle-type vehicle of the present invention includes an exhaust pipe attached to an engine provided in the saddle-type vehicle, a chamber connected to the downstream side of the exhaust pipe, and the like. A muffler connected to the chamber and a plurality of columnar catalyst devices provided in the chamber for purifying exhaust are provided, and the plurality of catalyst devices provide gaps in the left-right direction of the saddle-type vehicle. Arranged side by side with a gap, each inflow side end faces the front of the saddle-type vehicle, and each inflow side end is aligned in the front-rear direction of the saddle-type vehicle, and the chamber is the said. The inside of the chamber is divided in the front-rear direction of the saddle-mounted vehicle, and a plate-shaped partition portion forming an inflow chamber with the front wall of the chamber is provided, and the partition portion is an inflow of each of the plurality of catalyst devices. It has a plurality of insertion holes into which side ends are inserted, the exhaust pipe is opened in the inflow chamber, and the inflow end sides of the plurality of catalyst devices face each other through the plurality of insertion holes. The end surface of each of the inflow side end portions of the plurality of catalyst devices and the front surface of the partition portion are located in the same plane .

According to the present invention, it is possible to improve the sound deadening performance of the chamber and to activate the catalyst at an early stage without complicating the structure, while having a configuration in which a plurality of catalyst devices are housed in the chamber.

It is explanatory drawing which shows a part of the motorcycle which provided the exhaust system of the Example of this invention. It is explanatory drawing which looked at a part of the motorcycle in FIG. 1 from the lower side. It is a perspective view which shows the exhaust device of the Example of this invention. It is an external view which shows the chamber in the exhaust device of the Example of this invention. It is sectional drawing which shows the chamber seen from the arrow VV direction in FIG. It is sectional drawing which shows the chamber seen from the direction of arrow VI-VI in FIG. It is a perspective view which shows the catalyst device, the partition part and the support member provided in the chamber in the exhaust device of the Example of this invention. It is explanatory drawing which shows the modification of the exhaust device of the Example of this invention. It is explanatory drawing which shows the other modification of the exhaust device of the Example of this invention.

The exhaust device of the saddle-type vehicle according to the embodiment of the present invention includes an exhaust pipe attached to an engine provided in the saddle-type vehicle, a chamber connected to the downstream side of the exhaust pipe, and a muffler connected to the chamber. And a plurality of catalyst devices for purifying the exhaust gas.

Each of the plurality of catalyst devices is formed in a columnar shape. Further, a plurality of catalyst devices are provided in each chamber. In the chamber, a plurality of catalyst devices are arranged side by side with a gap in the left-right direction of the saddle-type vehicle, each inflow side end facing the front of the saddle-type vehicle, and each inflow side end. Are aligned in the front-rear direction of the saddle-mounted vehicle.

According to the exhaust device of the saddle-type vehicle according to the embodiment of the present invention, since the plurality of catalyst devices are arranged side by side with a gap in the left-right direction of the saddle-type vehicle, the catalyst devices in the chamber are arranged with each other. Exhaust gas after passing through each catalyst device can be passed through the gap, whereby the effect of reducing the exhaust noise of the chamber can be enhanced.

Further, since a plurality of catalyst devices are arranged side by side with a gap in the left-right direction of the saddle-mounted vehicle, the gap between the catalyst devices is used to cover the outer peripheral surface of each catalyst device in each catalyst device. The exhaust after passing through can be efficiently and evenly applied. As a result, the heat of the exhaust gas can be used to activate each catalyst device at an early stage. In addition, it is possible to prevent the activation of some of the catalyst devices among the plurality of catalyst devices from being delayed. Further, in order to evenly apply the exhaust gas to each catalyst device, it is not necessary to construct a complicated path for guiding the exhaust gas to each catalyst device, such as adding a bypass passage to the exhaust pipe.

Further, since the inflow side ends of the plurality of catalyst devices are aligned in the front-rear direction of the saddle-type vehicle, the exhaust gas flowing out from the exhaust pipe is sent to the front of each catalyst device in the chamber in each catalyst device. A space (inflow chamber) for flowing into the air can be easily secured.

Further, since the inflow side ends of the plurality of catalyst devices are aligned in the front-rear direction of the saddle-type vehicle, a large space can be easily secured behind each catalyst device in the chamber, and the chamber can be arranged. The muffling performance can be improved.

In addition, various sizes of columnar catalyst devices are available on the market, and it is possible to easily select a catalyst device suitable for the size of the chamber. This increases the degree of freedom in the layout of the catalyst device. Therefore, it is possible to easily set the layout of the catalyst device so that a large space for exhibiting a high exhaust noise reduction effect can be secured in the chamber. In addition, the cost of the exhaust system can be reduced by selecting an inexpensive catalyst device provided on the market.

FIG. 1 shows a part of a motorcycle 1 provided with an exhaust device according to an embodiment of the present invention. FIG. 2 is a view of a part of the motorcycle 1 in FIG. 1 as viewed from below. FIG. 3 shows an exhaust device 31 according to an embodiment of the present invention. The arrows drawn at the lower right of each of the drawings from FIGS. 1 to 7 are front (F), rear (B), left (L), right (R), and top as seen from the driver of the motorcycle 1. It points in the directions of (U) and bottom (D). When the directions are described in the following examples, the directions indicated by these arrows are followed.

In FIGS. 1 and 2, the body frame 2 of the motorcycle 1 includes a head pipe 3, a pair of main frames 4, and a pair of seat rails 5. The head pipe 3 is arranged on the upper side of the front portion of the motorcycle 1 as shown in FIG. 1, and is arranged on the middle portion in the left-right direction of the motorcycle 1 as shown in FIG. The pair of mainframes 4 are twin spar frames formed of, for example, an aluminum alloy, and each of them opens left and right from the head pipe 3 and extends rearward, and then bends downward near the middle portion in the front-rear direction of the motorcycle 1. It reaches the bottom of the motorcycle 1. The pair of seat rails 5 extend rearward from the rear upper side of the left and right mainframes 4, respectively.

Further, a swing arm 6 is rotatably supported on the lower rear side of the left and right main frames 4, and a rear wheel 7 is rotatably supported on the rear end side of the swing arm 6. Further, a rear suspension 8 is provided between the upper rear portion of the left and right main frames 4 and the swing arm 6. The upper end of the rear suspension 8 is connected to the brackets 9 provided on the left and right main frames 4, respectively, and the lower end of the rear suspension 8 is connected to the swing arm 6 via the rear suspension link 10. .. A side stand 11 is attached to the lower rear side of the main frame 4 on the left side. In the motorcycle 1 in FIG. 1 or 2, the steering shaft, front fork, front wheel, steering wheel, fuel tank, seat, cowl, etc. are not shown.

Further, for example, a parallel 4-cylinder 4-cycle engine 21 is provided between the left and right mainframes 4. The engine 21 includes a crankcase 22, a cylinder 23 provided on the crankcase 22, a cylinder head 24 provided on the cylinder 23, an oil pan 25 provided below the crankcase 22, and the like.

Further, the motorcycle 1 is provided with the exhaust device 31 according to the embodiment of the present invention. The exhaust device 31 is a device that discharges the exhaust gas from the engine 21 to the atmosphere, and has a function of purifying the exhaust gas and a function of reducing the exhaust noise. As shown in FIG. 3, the exhaust device 31 includes four exhaust pipes 33, 34, 35, 36, a pair of collecting pipes 37, 38, a chamber 41, and a pair of joint pipes 42, which correspond to the number of cylinders of the engine 21. It includes 43, a pair of mufflers 44, 45, two catalyst devices 46, 47, an exhaust gas sensor 48, and an exhaust valve 49.

As shown in FIG. 1, the inflow side ends of the four exhaust pipes 33, 34, 35, and 36 are connected to four exhaust ports arranged on the front surface of the cylinder head 24, respectively. The four exhaust pipes 33, 34, 35, and 36 extend downward from the exhaust port through the front of the cylinder 23 and the front of the crankcase 22, and then curve backward. As shown in FIG. 2, the outflow side ends (downstream side) of the four exhaust pipes 33, 34, 35, 36 are divided into two groups, and the collecting pipes 37 are combined into one for each group. It is connected to 38. That is, the outflow side ends of the two exhaust pipes 33 and 34 on the left side are connected to each other and connected to one collecting pipe 37 on the left side. Further, the outflow side ends of the two exhaust pipes 35 and 36 on the right side are connected to each other and connected to one collecting pipe 38 on the right side. Further, the oil pan 25 has a shape in which the lower portion thereof in the left-right direction protrudes downward. The outflow end side of the exhaust pipes 33, 34, 35, 36 and the two collecting pipes 37, 38 divided into two groups sandwich the downwardly protruding portion (convex portion) 25A of the oil pan 25. It is piped. Further, the outflow side ends of the two collecting pipes 37 and 38 are connected to the chamber 41, respectively.

The chamber 41 is arranged in the lower part of the middle portion in the front-rear direction of the motorcycle 1. Specifically, the front portion of the chamber 41 is located below the crankcase 22 and behind the oil pan 25. The front-rear middle portion of the chamber 41 is located below the pivot 12. The rear portion of the chamber 41 is located below the front portion of the swing arm 6, and the rear end portion of the chamber 41 reaches the position of the rear portion of the rear suspension link 10. Further, the chamber 41 is arranged in the middle portion in the left-right direction of the motorcycle 1.

The inflow side ends of the joint pipes 42 and 43 are connected to the chamber 41. The left joint pipe 42 extends from the chamber 41 to the left rear. The joint pipe 43 on the right side extends rearward to the right from the chamber 41. Further, the outflow side ends of the joint pipes 42 and 43 are connected to the mufflers 44 and 45, respectively. The mufflers 44 and 45 are arranged on the left and right sides of the rear portion of the motorcycle 1, respectively.

The two catalyst devices 46 and 47 are provided in the chamber 41, respectively, as shown in FIG. The exhaust gas sensor 48 is attached to the front portion of the chamber 41. The exhaust valve 49 is a valve for switching the exhaust flow rate, and is attached to the joint pipe 43 on the right side.

FIG. 4 shows the chamber 41 in the exhaust device 31. FIG. 5 shows a cross section of the chamber 41 as viewed from the direction of arrow VV in FIG. FIG. 6 generally shows a cross section of the chamber 41 as viewed from the direction of arrow VI-VI in FIG. FIG. 7 shows the catalyst devices 46 and 47, the partition portion 61, and the support member 63.

As shown in FIG. 4, the chamber 41 is formed in a box shape by four wall plates 51, 52, 53, 54 formed of metal plates. That is, the chamber 41 has a front lower wall plate 51 forming the lower front wall, a front upper wall plate 52 forming the upper front wall, a lower wall, a lower left wall, a lower right wall, and a lower rear wall forming the lower rear wall. It comprises a plate 53 and a rear upper wall plate 54 forming an upper wall, an upper left wall, an upper right wall and an upper rear wall. These wall plates 51, 52, 53, 54 are joined by welding, respectively.

Further, a pair of mounting brackets 55 are provided on the left and right portions on the upper surface side of the rear upper wall plate 54 (see FIG. 3). The chamber 41 is supported by these mounting brackets 55 at the lower part of the left and right mainframes 4 by a bridge portion 13 spanned between the mainframes 4.

Further, as shown in FIG. 6, a pair of collecting pipes are provided on the front left side and the front right side of the front wall of the chamber 41 formed by joining the front lower wall plate 51 and the front upper wall plate 52. A pair of inflow side connection holes 56 for connecting 37 and 38 are formed, respectively. Further, at the rear portion of the left wall of the chamber 41 formed by joining the rear lower wall plate 53 and the rear upper wall plate 54, a left joint pipe connecting hole 57 for connecting the left joint pipe 42 is provided. It is formed. Further, at the rear portion of the right wall of the chamber 41 formed by joining the rear lower wall plate 53 and the rear upper wall plate 54, a right joint pipe connecting hole 58 for connecting the right joint pipe 43 is provided. It is formed.

Further, the chamber 41 includes a partition portion 61 that divides the inside of the chamber 41 in the front-rear direction. The partition portion 61 is formed of metal in a plate shape. Further, the partition portion 61 is bent so that its edge portion extends rearward over the entire circumference by, for example, press working. The edge of the partition 61 is between the rear end of the front lower wall plate 51 and the front end of the rear lower wall plate 53, and the rear end of the front upper wall plate 52 and the rear end of the rear upper wall plate 54. It is sandwiched between the two, and is joined to each of the front lower wall plate 51, the rear lower wall plate 53, the front upper wall plate 52, and the rear upper wall plate 54 by welding. In the chamber 41, the partition portion 61 forms an inflow chamber R1 between the front wall of the chamber 41 and the partition portion 61, and an outflow chamber R2 is formed between the partition portion 61 and the rear wall of the chamber 41. ing. Further, as shown in FIG. 7, a pair of insertion holes 62 for inserting the inflow side end portions 46A and 47A of the two catalyst devices 46 and 47 are formed in the left portion and the right portion of the partition portion 61, respectively. ing.

As shown in FIG. 6, two catalyst devices 46 and 47 are provided in the front portion in the outflow chamber R2. Each catalyst device 46, 47 is a three-way catalyst that purifies exhaust gas. Each of the catalyst devices 46 and 47 is formed in a columnar shape, and one end side in the axial direction is the inflow side end portions 46A and 47A, and the other end side in the axial direction is the outflow side end portions 46B and 47B. Further, the two catalyst devices 46 and 47 are the same product and have the same size.

In the outflow chamber R2, the catalyst devices 46 and 47 are arranged in front of the intermediate position in the front-rear direction of the chamber 41, respectively. Further, the catalyst devices 46 and 47 are arranged side by side with a gap G1 in the left-right direction. Further, the catalyst devices 46 and 47 are arranged so that their respective axes are parallel to each other. Further, in the catalyst devices 46 and 47, the inflow side ends 46A and 47A face forward, and the inflow side ends 46A and 47A are aligned in the front-rear direction. Further, the catalyst devices 46 and 47 are arranged so that a gap G2 is formed between the outer peripheral surface thereof and the wall surface in the chamber 41.

The catalyst devices 46 and 47 are supported in the outflow chamber R2 by an insertion hole 62 and a support member 63 formed in the partition portion 61. That is, as shown in FIG. 7, the inflow side ends 46A and 47A of the catalyst devices 46 and 47 are inserted into the insertion holes 62 of the partition portion 61, respectively, and are fixed to the edges of the insertion holes 62 by welding or the like. Further, the outflow side end portions 46B and 47B of the catalyst devices 46 and 47 are inserted into the inner peripheral side of the ring-shaped support member 63 and fixed to the inner peripheral side edge of the support member 63 by welding or the like. .. Then, as shown in FIG. 6, the outer peripheral side of the support member 63 is fixed to the wall surface in the chamber 41 by welding or the like. The support member 63 is formed in a ring shape that is long in the left-right direction, and the outflow side ends 46B and 47B of the two catalyst devices 46 and 47 are left portions of one continuous space on the inner peripheral side of the support member 63. And are inserted in the right part respectively. In the outflow side end portion 46B of the catalyst device 46 on the left side, the outer peripheral surface of the left half of the outflow side end portion 46B is fixed to the inner peripheral surface of the left portion of the support member 63, and the outflow side end portion of the catalyst device 47 on the right side. In 47B, the outer peripheral surface of the right half of the outflow side end portion 47B is fixed to the inner peripheral surface of the right portion of the support member 63. Then, there is a gap between the intermediate portion on the inner peripheral side of the support member 63, that is, the outflow side ends 46B and 47B of the two catalyst devices 46 and 47. As a result, the gap G1 between the catalyst devices 46 and 47 communicates with the rear space S in the outflow chamber R2.

Further, the insertion holes 62 are formed in the partition portion 61 at positions separated from each other and away from the wall surface in the chamber 41. Further, the inner peripheral surface of the support member 63 is separated from the wall surface in the chamber 41. Therefore, since the two catalyst devices 46 and 47 are supported by the insertion hole 62 of the partition portion 61 and the support member 63 as described above, a gap G1 is provided between the two catalyst devices 46 and 47, and each of them has a gap G1. There is also a gap G2 between the outer peripheral surfaces of the catalyst devices 46 and 47 and the wall surface in the chamber 41.

Further, in the rear part of the outflow chamber R2, a space S is formed from the end faces of the outflow side ends 46B and 47B of the catalyst devices 46 and 47 to the vicinity of the rear wall surface in the chamber 41, and the space S is formed in the space S. , No object is placed that blocks or divides the space S. Further, the left joint pipe 42 is connected to the left joint pipe connection hole 57 formed on the rear left side of the outflow chamber R2, whereby the inside of the outflow chamber R2 communicates with the inside of the left joint pipe 42. .. Further, the right joint pipe 43 is connected to the right joint pipe connection hole 58 formed on the rear right side of the outflow chamber R2, whereby the inside of the outflow chamber R2 communicates with the inside of the right joint pipe 43.

On the other hand, in the inflow chamber R1, a pair of collecting pipes 37 and 38 are connected to the inflow side connecting holes 56 formed in the left portion and the right portion of the front wall of the chamber 41, respectively, and the collecting pipes 37, 38 is open in the inflow chamber R1. Further, in the inflow chamber R1, the end faces of the inflow side end portions 46A and 47A of the catalyst devices 46 and 47 face each other through the insertion hole 62 of the partition portion 61. Further, the end faces of the inflow side end portions 46A and 47A of the catalyst devices 46 and 47 and the front surface of the partition portion 61 are located in the same plane. Further, the end portions (outflow side end portions 37A, 38A) of the collecting pipes 37 and 38 that are open into the inflow chamber R1 are the inflow side end portions 46A of the catalyst device 46 facing the inflow chamber R1. The end face and the end face of the inflow side end portion 47A of the catalyst device 47 are oriented in the direction in which either one is located. That is, as shown in FIG. 6, the outflow side end 37A of the left collecting pipe 37 is gently bent to the right so as to face the direction in which the end surface of the inflow side end 46A of the left catalyst device 46 is located. .. Further, the outflow side end 38A of the right collecting pipe 38 is gently bent to the left so as to face the direction in which the end surface of the inflow side end 47A of the right catalyst device 47 is located. In this embodiment, since the axis of the collecting pipe 37 on the left side and the axis of the catalyst device 46 on the left side are not significantly deviated from each other, the bending angle of the outflow side end portion 37A of the collecting pipe 37 on the left side is small. Similarly, since the axis of the collecting pipe 38 on the right side and the axis of the catalyst device 47 on the right side are not significantly deviated from each other, the bending angle of the outflow side end 38A of the collecting pipe 38 on the right side is small.

Further, a hole for attaching the exhaust gas sensor 48 is formed in the right portion of the front upper wall plate 51 of the chamber 41, and the exhaust gas sensor 48 is attached to the hole. The exhaust gas sensor 48 detects the oxygen concentration of the exhaust gas flowing out from the two collecting pipes 37 and 38, respectively. The exhaust gas sensor 48 may be an O ₂ (oxygen) sensor or an A / F (air-fuel ratio) sensor. The detection result by the exhaust gas sensor 48 is used for fuel injection amount control and the like for causing the combustion of fuel in the engine 21 to be performed in the vicinity of the stoichiometric air-fuel ratio and effectively exerting the exhaust purification effect by the catalyst devices 46 and 47.

In the exhaust device 31 having such a configuration, the exhaust discharged from each exhaust port of the engine 21 circulates in the four exhaust pipes 33, 34, 35, 36, and then the two exhausts on the left side. The exhaust gas flowing through the pipes 33 and 34 merges with each other and flows through the collecting pipe 37 on the left side. Further, the exhaust gas flowing through the two exhaust pipes 35 and 36 on the right side merges with each other and flows through the collecting pipe 38 on the right side. Then, as shown in FIG. 6, the exhaust gas flowing through the two collecting pipes 37 and 38 flows into the inflow chamber R1 of the chamber 41. The exhaust gas that has flowed into the inflow chamber R1 subsequently flows into the catalyst devices 46 and 47 from the inflow side ends 46A and 47A of the catalyst devices 46 and 47, is purified in the catalyst devices 46 and 47, and is purified in the catalyst devices 46 and 47. , 47 outflow side ends 46B, 47B to the rear space S in the outflow chamber R2. The exhaust gas that has flowed out to the rear space S in the outflow chamber R2 is not only in the rear space S in the outflow chamber R2, but also in the gap G1 between the catalyst devices 46 and 47, and in the catalyst devices 46 and 47 and the chamber 41. The gap G2 between the wall surface and the wall surface is circulated. Exhaust noise is reduced by the exhaust gas flowing out from the catalyst devices 46 and 47 flowing through the rear space S, the gap G1 and the gap G2 in the outflow chamber R2. Further, when the exhaust gas flowing out from the catalyst devices 46 and 47 flows through the gap G1 and the gap G2, the exhaust gas hits the outer peripheral surface of the catalyst devices 46 and 47, and the temperature of the catalysts 46 and 47 rises due to the heat of the exhaust gas. To do. Then, the exhaust gas in the outflow chamber R2 flows into the joint pipes 42 and 43, sequentially circulates in the joint pipes 42 and 43 and in the mufflers 44 and 45, and is discharged to the atmosphere. Exhaust noise is further reduced by circulating the exhaust in the mufflers 44 and 45.

As described above, according to the exhaust device 31 of the embodiment of the present invention, since the two catalyst devices 46 and 47 are arranged side by side with a gap G1 in the left-right direction, the inside of each catalyst device 46 and 47 The exhaust gas after passing through the gap G1 can be circulated. Thereby, the effect of reducing the exhaust noise by the chamber 41 can be enhanced. Further, since a gap G2 is formed between the outer peripheral surfaces of the catalyst devices 46 and 47 and the wall surface in the chamber 41, the exhaust gas after passing through the catalyst devices 46 and 47 flows through the gap G2. This also makes it possible to enhance the effect of reducing the exhaust noise of the chamber 41.

Further, by circulating the exhaust gas after passing through the catalyst devices 46 and 47 through the gaps G1 and G2, the exhaust gas can be applied to the outer peripheral surfaces of the catalyst devices 46 and 47. As a result, the catalyst devices 46 and 47 can be activated at an early stage by utilizing the heat of the exhaust gas. Further, since the catalyst devices 46 and 47 are arranged in the common continuous outflow chamber R2, substantially the same amount of exhaust gas after passing through the catalyst devices 46 and 47 is substantially applied to the outer peripheral surfaces of the catalyst devices 46 and 47. It can be applied at the same time, and the catalyst devices 46 and 47 can be heated evenly. This makes it possible to prevent the activation of one of the catalyst devices 46 and 47 from being delayed. Further, early activation of each catalyst device 46, 47 is performed by a simple configuration in which two catalyst devices 46, 47 are arranged in the chamber 41, a gap G1 is formed between the two, and a gap G2 is formed around the two. Can be planned.

Further, according to the exhaust device 31 of the embodiment of the present invention, by arranging the catalyst devices 46 and 47 in front of the intermediate position of the chamber 41, a large space S can be secured in the rear portion in the chamber 41. The space S can be used to enhance the effect of reducing exhaust noise. Further, since the catalyst devices 46 and 47 are arranged so that the respective inflow side end portions 46A and 47A are aligned in the front-rear direction, the space S can be increased and the exhaust sound muffling performance can be improved.

Further, according to the exhaust device 31 of the embodiment of the present invention, the inflow chamber R1 is formed in the chamber 41 by dividing the chamber 41 by the partition portion 61, and the collecting pipes 37 and 38 are opened in the inflow chamber R1. The structure is such that the end faces of the inflow side ends 46A and 47A of the catalyst devices 46 and 47 face each other. As a result, the exhaust gas sent to the chamber 41 through the collecting pipes 37 and 38 can be evenly flowed into the catalyst devices 46 and 47, respectively.

Further, according to the exhaust device 31 of the embodiment of the present invention, the end faces of the inflow side end portions 46A and 47A of the catalyst devices 46 and 47 and the front surface of the partition portion 61 are positioned in the same plane. As a result, the exhaust gas can be smoothly flowed into the catalyst devices 46 and 47, and the flow of the exhaust gas in the catalyst devices 46 and 47 can be improved. Further, the exhaust gas can be evenly flowed into the respective catalyst devices 46 and 47, and the purification efficiency of the exhaust gas by the two catalyst devices 46 and 47 can be improved. For example, it is possible to prevent the exhaust gas purification effect of the two catalyst devices 46 and 47 from being insufficiently exhibited because the amount of exhaust gas flowing into one of the catalyst devices is small.

Further, according to the exhaust device 31 of the embodiment of the present invention, by opening the collecting pipes 37 and 38 into the inflow chamber R1, respectively, the exhaust gas sent through the collecting pipes 37 and 38 is introduced into the inflow chamber R1. Can be collected. Then, by detecting the oxygen concentration of the exhaust gas collected in the inflow chamber R1 with the exhaust gas sensor 48, it is possible to detect the average oxygen concentration of the exhaust gas flowing into the respective catalyst devices 46 and 47. Therefore, the accuracy of oxygen concentration detection for performing fuel injection amount control (air-fuel ratio control) can be improved, and the accuracy of fuel injection amount control can be improved. Therefore, the exhaust gas purification effect of each of the catalyst devices 46 and 47 can be surely exhibited. Further, a single exhaust gas sensor 48 may be provided, that is, it is not necessary to provide a plurality of exhaust gas sensors for each of the exhaust pipes 33, 34, 35, 36, or for each of the collecting pipes 37, 38. The cost can be reduced.

Further, according to the exhaust device 31 of the embodiment of the present invention, the outflow side ends 37A and 38A of the collecting pipes 37 and 38 face the directions in which the inflow side ends 46A and 47A of the catalyst devices 46 and 47 are located, respectively. Therefore, the exhaust gas that has flowed into the inflow chamber R1 through the collecting pipes 37 and 38 can be smoothly flowed into the catalyst devices 46 and 47.

Further, according to the exhaust device 31 of the embodiment of the present invention, the chamber 41 is arranged behind the oil pan 25, and the outflow end side of the exhaust pipes 33, 34, 35, 36 and the collecting pipes 37, 38 are the oil pan 25. Since the pipes are laid so as to sandwich the convex portion 25A of the above, the lengths of the exhaust pipes 33, 34, 35, 36 and the collecting pipes 37, 38 can be easily extended in order to realize the desired engine characteristics. it can.

Further, in the exhaust device 31 of the embodiment of the present invention, columnar catalyst devices 46 and 47 are adopted. As the columnar catalyst devices 46 and 47, products of various sizes are offered on the market, and the catalyst devices 46 and 47 suitable for the size of the chamber 41 can be easily selected. This increases the degree of freedom in the layout of the catalyst devices 46 and 47. Therefore, the gap G1, the gap G2, and the space S can be easily secured in the chamber 41. Further, by selecting an inexpensive catalyst device provided on the market as the catalyst devices 46 and 47, the cost of the exhaust device 31 can be reduced. Further, since the plurality of catalyst devices 46 and 47 are the same product and have the same size, the layout of the catalyst devices 46 and 47 can be further facilitated, and the cost of the exhaust device 31 can be further reduced.

In the above-described embodiment, the two catalyst devices 46 and 47 are arranged side by side with a gap in the left-right direction of the motorcycle 1, and the respective inflow side end portions 46A and 47A face the front of the motorcycle 1. And, they are aligned in the front-rear direction of the motorcycle 1. As described above, the arrangement of the catalyst devices 46 and 47 is determined based on the front-rear direction of the motorcycle 1 and the left-right direction of the motorcycle 1, but the motorcycle 1 which is the reference of the arrangement of the catalyst devices 46 and 47 The front-rear direction is not limited to the strict front-rear direction that penetrates the intermediate position in the vehicle width direction of the motorcycle 1. The front-rear direction of the motorcycle 1, which is the reference for the arrangement of the catalyst devices 46 and 47, is a direction inclined within a range of less than about -22.5 to less than about +22.5 degrees in the horizontal plane with respect to the above-mentioned strict front-rear direction. including. Further, the left-right direction of the motorcycle 1 which is the reference for the arrangement of the catalyst devices 46 and 47 is a direction orthogonal to the front-rear direction of the motorcycle 1 which is the reference for the arrangement of the catalyst devices 46 and 47 in the horizontal plane. For example, as shown in FIG. 8, the front-rear direction B of the chamber 41 is tilted in the horizontal plane within a range of less than about -22.5 to less than about +22.5 degrees with respect to the strict front-rear direction A of the motorcycle 1. If so, the arrangement of the catalyst devices 46 and 47 may be determined with reference to the front-rear direction B.

Further, in the above-described embodiment, the case where the catalyst devices 46 and 47 are arranged so that their axes are parallel to each other has been given as an example, but the present invention is not limited to this, and the catalyst is not limited to this, for example, as shown in FIG. The catalyst devices 46 and 47 are provided so that the inflow side ends of the devices 46 and 47 face the front of the saddle-mounted vehicle and the inflow-side ends of the devices 46 and 47 are aligned in the front-rear direction of the saddle-mounted vehicle. They may be tilted at different angles in the horizontal plane.

Further, in the above-described embodiment, cylindrical catalyst devices are used as the catalyst devices 46 and 47, but the “cylindrical” as used herein also includes an elliptical column.

Further, in the above-described embodiment, the case where the chamber 41 is arranged in the left-right intermediate portion of the motorcycle 1 is taken as an example, but the chamber 41 is arranged on the right side or the left side of the left-right intermediate portion of the motorcycle 1. May be good.

Further, the number of cylinders of the engine and the number of exhaust pipes may be 2 or more, and the number of collecting pipes may be 3 or more. Further, the number of joint pipes and the number of mufflers may be 1. Further, the exhaust pipe may be directly connected to the chamber without providing the collecting pipe. Further, the number of catalyst devices may be 3 or more.

Further, the present invention is not limited to motorcycles, but can be applied to other types of saddle-type vehicles such as motorcycles and buggies.

Further, the present invention can be appropriately modified within the scope of the claims and within a range not contrary to the gist or idea of the invention that can be read from the entire specification, and the exhaust device for a saddle-type vehicle accompanied by such a modification is also the present invention. It is included in the technical idea of the invention.

1 Motorcycle 21 Engine 25 Oil pan 25A Convex 31 Exhaust device 33, 34, 35, 36 Exhaust pipe 37, 38 Collective pipe 37A, 38A Outflow side end 41 Chamber 42, 43 Joint pipe 44, 45 Muffler 46, 47 Catalyst Equipment 46A, 47A Inflow side end 46B, 47B Outflow side end 48 Exhaust gas sensor 61 Partition 62 Insertion hole 63 Support member R1 Inflow chamber R2 Outflow chamber G1, G2 Gap S space

Claims (7)

The exhaust pipe attached to the engine installed in the saddle-type vehicle,
A chamber connected to the downstream side of the exhaust pipe and
With the muffler connected to the chamber,
Each of the chambers is provided with a plurality of columnar catalyst devices for purifying exhaust gas.
The plurality of catalyst devices are arranged side by side with a gap in the left-right direction of the saddle-type vehicle, the inflow side ends thereof face the front of the saddle-type vehicle, and the inflow side ends thereof. They are aligned in the front-rear direction of the saddle-mounted vehicle.
The chamber is provided with a plate-shaped partition that divides the inside of the chamber in the front-rear direction of the saddle-type vehicle and forms an inflow chamber with the front wall of the chamber.
The partition has a plurality of insertion holes for inserting the respective inflow side ends of the plurality of catalyst devices.
The exhaust pipe is open in the inflow chamber, and the inflow end sides of the plurality of catalyst devices face each other through the plurality of insertion holes.
An exhaust device for a saddle-type vehicle, characterized in that the end surface of each of the inflow side end portions of the plurality of catalyst devices and the front surface of the partition portion are located in the same plane. The saddle-type vehicle according to claim 1, wherein the plurality of catalyst devices are supported in the chamber so that a gap is formed between the outer peripheral surface of the catalyst device and the wall surface of the chamber. Exhaust system. With a plurality of the exhaust pipes
In the inflow chamber, the plurality of exhaust pipes or a plurality of collecting pipes in which the plurality of exhaust pipes divided into a plurality of groups are combined into one for each of the plurality of groups and connected to each other are opened. ,
The first or second aspect of the present invention, wherein the inflow chamber is provided with a single exhaust gas sensor for detecting the oxygen concentration of the exhaust gas flowing out from the plurality of exhaust pipes or the plurality of collecting pipes, respectively. Exhaust system for saddle-mounted vehicles. With a plurality of the exhaust pipes
In the inflow chamber, the plurality of exhaust pipes or a plurality of collecting pipes in which the plurality of exhaust pipes divided into a plurality of groups are combined into one for each of the plurality of groups and connected to each other are opened. ,
The end of the plurality of exhaust pipes or the plurality of collecting pipes that is open into the inflow chamber faces the direction in which the inflow side end of any of the plurality of catalyst devices is located. The exhaust device for a saddle-type vehicle according to claim 1 or 2, wherein the exhaust device is provided. With a plurality of the exhaust pipes
In the inflow chamber, the plurality of exhaust pipes or a plurality of collecting pipes in which the plurality of exhaust pipes divided into a plurality of groups are combined into one for each of the plurality of groups and connected to each other are opened. ,
The chamber is located behind the oil pan
The exhaust device for a saddle-type vehicle according to claim 1 or 2 , wherein the plurality of exhaust pipes or the plurality of collecting pipes are piped so as to sandwich a part of the oil pan. The saddle-type vehicle according to any one of claims 1 to 5 , wherein the plurality of catalyst devices are arranged in front of the intermediate position of the chamber in the front-rear direction of the saddle-type vehicle. Exhaust device. The exhaust device for a saddle-type vehicle according to any one of claims 1 to 6 , wherein the plurality of catalyst devices each have the same size.

Images