MX2007006344A

MX2007006344A - Catalyst arrangement structure for motorcycle .

Info

Publication number: MX2007006344A
Application number: MX2007006344A
Authority: MX
Inventors: Hideki Ikeda; Masaaki Yamaguchi; Yasuo Narazaki; Takuhei Kusano; Hiroshi Inokawa
Original assignee: Honda Motor Co Ltd
Priority date: 2006-05-31
Filing date: 2007-05-29
Publication date: 2008-12-12
Also published as: BRPI0702557A; JP2008008279A; TWI332544B; KR100864769B1; JP4693733B2; MY145188A; PE20080616A1; TW200745445A; BRPI0702557B1; KR20070115634A; AR060969A1; CN101082296A; CN101082296B

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst arrangement structure for a motorcycle for mounting a catalyst chamber with a compact configuration. ; SOLUTION: In exhaust passages 62 and 63 corresponding to an entrance of the catalyst chamber 80, the axis of a catalyst 85 is aligned in the passage direction of one exhaust passage 63, while the other exhaust passage 62 is opened within the longitudinal width of the catalyst 85. ; COPYRIGHT: (C)2008,JPO&INPIT.

Description

[Title of the Invention] A STRUCTURE OF THE DISPOSAL OF THE CATALYST OF A MOTORCYCLE [Technical Field]

[0001] The present invention relates to the structure of the catalyst arrangement of a motorcycle having a catalyst chamber in an intermediate portion of a motorcycle. an exhaust pipe that connects an exhaust port and a silencer. [Prior Art]

[0002] Generally, a motorcycle is known which forms a catalyst chamber in an intermediate portion of an exhaust pipe that connects an exhaust pipe and a silencer. In this type of motorcycle, in order to provide a sufficient purification function for the catalyst in the catalyst chamber, it is convenient to install the catalyst in a central position of the flow of an exhaust gas thus allowing the exhaust gas and the catalyst to be in contact with each other for a long time. However, when the catalyst is installed in the central position of the exhaust gas flow, the flow velocity of the exhaust gas is greater in the central position of the exhaust gas flow than the peripheral portion in the catalyst chamber and by therefore, the flow velocity of the exhaust gas flowing into the catalyst becomes excessively high in the central position in the catalyst chamber and due to this reason the purification time of the exhaust gas is reduced.

[0003] To avoid this phenomenon, in a conventional manner, the structure of the catalyst arrangement has been proposed in which a large capacity catalyst chamber is connected to the intermediate portion of the exhaust pipe which has an outlet and an inlet and extends linearly , the catalyst is located in the catalyst chamber with an axis thereof displaced from an axis of the catalyst chamber, a flow velocity of the exhaust gas flowing into the catalyst from the inlet is first reduced in the chamber and, subsequently, the exhaust gas is introduced into the catalyst and is sufficiently purified, and therefore, the exhaust gas is discharged through an outlet of the chamber (see patent document 1, for example). [Patent Document 1] JP-A-2002- 317627 [Presentation of the Invention] [Problems That the Invention Must Resolve]

[0004] However, in the conventional structure mentioned above, an axle of the exhaust pipe and the axle of the catalyst are displaced from each other and therefore, the catalyst chamber has a large size. In addition, the catalyst chamber is installed in a straight portion of the exhaust pipe and therefore, the exhaust pipe is elongated thereby avoiding the compact arrangement of the catalyst chamber.

[0005] Accordingly, an object of the invention is to provide a structure of the catalyst arrangement of a motorcycle that adapts a catalyst chamber in a compact manner. [Means to solve the problem]

[0006] In order to overcome the aforementioned disadvantages, the invention provides the structure of the catalyst arrangement of a motorcycle having a catalyst chamber in an intermediate portion of an exhaust pipe that connects an exhaust port of a cylinder head. and a silencer, where outside the exhaust ducts corresponding to an inlet and outlet of the catalyst chamber, one axis of a catalyst is aligned with the direction of the duct of an exhaust duct, and another exhaust duct is open within of a width in the direction of the catalyst length. According to the invention, outside the exhaust ports corresponding to the inlet and outlet of the catalyst chamber, the catalyst shaft is aligned with the direction of the duct of an exhaust duct, and another exhaust duct is open inside. of the width in the direction of the length of the catalyst and therefore, the catalyst chamber can be connected to an inclined tube constituting the exhaust pipe thereby accomplishing the compact arrangement of the catalyst chamber.

[0007] In the constitution mentioned above, it is preferable to arrange the catalyst along an axis of an exhaust duct, and to realize an opening formed in a side surface of the catalyst chamber constituting an opening of another exhaust duct in front of a side surface of the catalyst. Due to this constitution, the catalyst is placed along the axis of an exhaust duct and therefore, the catalyst chamber can have a miniature size. In addition, the opening formed in the lateral surface of the catalyst chamber faces the lateral surface of the catalyst and therefore the flow velocity of the exhaust gas entering the inner part of the catalyst from the surrounding area of the catalyst and passing through the catalyst can be suppressed.

[0008] Furthermore, in the constitution mentioned above, the opening formed in the lateral surface of the catalyst chamber may preferably be an opening that is directed towards the exhaust port. Due to this constitution, the temperature of the catalyst can easily reach an activation temperature due to the heat of the high temperature exhaust gas coming from the exhaust port, and at the same time, the water from the outside is hardly introduced into the opening formed in the lateral surface avoiding in this way that the catalyst is splashed with water.

[0009] Furthermore, in the constitution mentioned above, the catalyst can preferably be located in a recessed portion of the catalyst chamber. Due to this constitution, an additional fixing member becomes necessary to fix the catalyst and therefore, the manufacturing cost can be reduced.

[0010] Furthermore, in the aforementioned constitution, another exhaust duct can preferably be communicated with the catalyst chamber in an off-center position of a catalyst in the catalyst chamber. Due to this constitution, it is possible to allow the exhaust gas to pass through the catalyst after reducing the flow velocity of the exhaust gas in the inside the catalyst chamber, thus avoiding the generation of catalyst vibrations or a similar situation. [001 1] Furthermore, in the aforementioned constitution, a protruding portion that slopes to one side of the engine along a cylinder block of the engine and a crankcase can be preferably formed in the catalyst chamber, and another conduit Exhaust can be communicated preferably with the protruding potion. Due to this constitution, it is possible to place the protruding portion in a defined dead space between the cylinder block and the casing thus improving the efficiency of the arrangement of the protruding portion.

[0012] In addition, in the aforementioned constitution, another exhaust duct may preferably be formed in a form such that the exhaust duct is wrapped around the catalyst chamber and communicates with a lateral surface of the catalyst chamber. Due to this constitution, it is possible to allow the exhaust gas to flow smoothly.

[0013] Furthermore, in the constitution mentioned above, the catalyst chamber can preferably be located below the cylinder of a horizontal motor. Due to this constitution, by placing the catalyst chamber below the horizontal engine cylinder, it is possible to prevent the occurrence of a situation in which a lower base height of the vehicle is reduced due to the catalyst chamber or the occurrence of a situation in which the transverse angle of the vehicle is limited. [Advantages of the Invention]

[0014] According to the invention, outside the exhaust duct corresponding to the inlet and outlet of the catalyst chamber, the axis of the catalyst is aligned with the direction of the duct of an exhaust duct, and another exhaust duct is opens within the width in the direction of the length of the catalyst and in this way, the catalyst chamber can be connected to an inclined tube constituting the exhaust pipe thereby accomplishing the compact arrangement of the catalyst chamber. Further, by placing the catalyst along the axis of an exhaust duct, and by allowing the formation of an opening in a side surface of the catalyst chamber constituting an opening in another exhaust duct to face a surface side of the catalyst, the catalyst chamber may have a miniature size, and at the same time, the flow velocity of the exhaust gas entering the inner part of the catalyst from the surrounding area of the catalyst and passing through the catalyst may be suppressed. In addition, the opening formed in the lateral surface of the catalyst chamber is formed from the opening which is directed towards the exhaust port and therefore, the catalyst temperature can easily reach an activation temperature due to the heat of the gas of high temperature exhaust and, at the same time, the water from the outside hardly penetrates the opening formed in the lateral surface thus preventing the catalyst from splashing with water. In addition, the catalyst is placed in the recessed portion of the catalyst chamber and therefore, an additional fixing member to fix the catalyst is unnecessary, whereby the cost of the catalyst can be reduced. manufacture.

[0015] In addition, by allowing another exhaust conduit to communicate with the catalyst chamber in an off-center position of a catalyst in the catalyst chamber, it is possible to allow the exhaust gas to pass through the catalyst after reducing the velocity of exhaust gas flow in the inner part of the catalyst chamber, thus avoiding the generation of catalyst vibrations and similar situations. Further, by forming the protruding portion that slopes toward the engine side along the cylinder block and the engine crankcase in the catalyst chamber, and by allowing another exhaust conduit to communicate with the protruding portion, it is possible to Place the protruding portion in the dead space defined between the cylinder block and the crankcase. Further, by forming another exhaust duct in a form such that another exhaust pipe is wrapped around the catalyst chamber and communicating with a lateral surface of the catalyst chamber, it is possible to allow the exhaust gas to flow smoothly. Additionally, the catalyst chamber is located below the horizontal motor cylinder and therefore, it is possible to avoid the occurrence of a situation in which the lower base height of the vehicle is reduced due to the catalyst chamber or the occurrence of a situation in which the transverse angle of the vehicle is limited. [BEST MODE FOR CARRYING OUT THE INVENTION]

[0016] An embodiment of the invention is explained together with the illustrations that are attached below. Here, in the explanations, the descriptions of the directions as backwards and forwards, right and left or up and down indicate the directions with respect to the body of a vehicle. [First embodiment] Figure 1 shows a side view of a motorcycle according to a first embodiment. This motorcycle 1 includes a structure of the body of the vehicle 2, a pair of front right and left forks 3 with a rotating support in a lead tube 20 mounted on a front end of the body structure of the vehicle 2, a handle of direction 4 which is mounted in the upper end portions of the front forks 3, a front wheel 5 having a rotary support in the lower end portions of the front forks 3, a motor 6 having a support in the structure of the vehicle body 2 substantially in the center of the vehicle body a rear fork 7 having a support in the structure of the vehicle body 2 in a vertically rolling form, a rear wheel 8 having a rotating support in the portion of the rear end of the rear fork 7, a pair of right and left rear shock absorbers 9 which are placed between a rear portion of a rear fork 7 and the structure of the vehicle body 2, a fuel tank 10 having support in a rear portion above the structure of the vehicle body 2, a storage box 1 1 that has a support in the structure of the body of the vehicle 2, a seat 12 which is placed on the storage box 1 1, a hold bar 13 which is positioned behind the seat 12, and a cover of the body of the vehicle 14 made of a synthetic resin covering the structure of the vehicle body 2.

[0017] The vehicle body cover 14 includes a front cover 14A covering a front portion of the body structure of the vehicle 2, a pair of right and left leg shields 14B that cover the front portions of a driver's legs, a pair of right and left front side covers 14C that cover a front portion of the engine 6, an upper deck of the main frame 14D connecting the upper portions of the front side covers 14C, a pair of right and left rear side covers 14E covering a lower portion of the storage box 1 1, and a rear body cover 14F covering the remaining portions of the storage box 1 1 and the fuel tank 10 on both sides. Here, the leg guards 14B, the front side covers 14C and the upper cover of the main structure 14D are formed integrally with each other. In addition, a headlight 15 and screens 16 are placed on the front cover 14A, a rear headlight 17 is positioned at the rear end of the rear body cover 14F, and a front bumper 18 covering the front wheel 5 is placed on the rear wheel. the front fork 3.

[0018] The structure of the vehicle body 2 includes an arrival tube 20, a main structure 21 extending in the rear and lower direction from the arrival tube 20 in the center of the vehicle body. , a pair of right and left rear structures 22 that connect to the rear portions of the main structure 22 and extend in the back and oblique direction upper, a pair of right and left pivot plates 23 which are attached to the front portions of the respective rear structures 22, and a pair of support structures 24 connecting the intermediate portions of the respective pivot plates 23 and the rear structures respective 22. The storage box 1 1, the fuel tank 10, the cover of the vehicle body 14 and similar parts are mounted on the rear structure 22, and the seat 12 that can cover the storage box 12 and the tank of fuel 10 from above is mounted on the rear structure 22 in a manner that can open and close. In addition, the upper portions of the rear shock absorbers 9 are connected to a rear portion of the rear structure 22 in the form of brackets of the rear shock absorber 22A at a rear portion of the rear structure 22.

[0019] To the pivot plate 23, is connected the rear fork 7 that supports the rear wheel 8, a main leg 30 for parking the vehicle body in a vertical form, and a side leg 31 for parking the vehicle body in an inclined position. The rear fork 7 has a front end thereof with a pivotal support on both pivot plates 23 in the form of a pivot pin 7A, and has a support with a vertical rolling form using the pivot axis 7A as a pivot point. support for.

[0020] The main leg 30 has one end thereof with a pivoting support on both pivot plates 23 in the form of a pivot shaft 34 which passes through both pivot plates 23 at a position below the pivot pin 7A . The main leg 30, as shown in Figure 2, is constituted integrally by an insertion portion 30A in which the pivot shaft 34 passes through, a pair of portions of the right and left leg 30B extending from the insertion portion 30A, a portion of the plug 30C extending to a side of the center of the vehicle body from a portion of the leg 30B (the portion of the right leg in this embodiment), and a resting portion of the leg 30D extending from the portion of the left leg 30B. By using the pivot shaft 34 as a fulcrum, the main leg 30 can be rotated from a position in which the portion of the left leg 30B is directed rearwardly with respect to the vehicle body shown in Figure 1 ( corresponding to a stored position) to a position in which the portion of the left leg 30B is directed downward with respect to the vehicle body (corresponding to a stopping position of the vehicle).

[0021] The side leg 31 has a rotatable support on the left pivot plate 23 by the use of a bolt 35. Figure 1 shows a condition in which the side leg 31 is projected. Here, in Figure 1 and Figure 2, a pair of right and left main stirrups 36 are shown in which a driver sitting on the front portion of a seat 12 places his leg, a shift pedal 37 and a pedal of brake 38 manipulating the driver, and a pair of stirrups of the right and left rear seat 39 in which a person sitting in the back portion of the seat 12 places his leg.

[0022] On both sides of the intermediate portions of the main structures 21, as shown in Figure 1, a support is mounted suspended from the motor 40. The motor 6 has a supporting support suspended from the motor 40 and the pivot plate 23. The motor 6 is a horizontal single-cylinder motor (horizontal motor) which includes a crankcase 41, a block cylinder 42 that is connected to a front portion of the crankcase 41, a cylinder head 43 that is connected to a front portion of the cylinder block 42, and an upper cover 44 that is connected to a front portion of the cylinder head 43, where a cylinder inside the cylinder block 42 is placed horizontally.

[0023] With respect to this cylinder block 42, a piston is located inside a cylinder 42A in an alternative manner. In the crankcase 41, a crankshaft is housed which is connected to the aforementioned piston in the form of a connecting rod, a centrifugal clutch mechanism and a transmission in which the output shaft 6A of the motor 6 and the kickstarter 6B have a pivot support and, at the same time, constitutes a power transmission mechanism between the crankshaft and the output shaft 6A and similar parts. The transmission of power to the rear wheel 8 from the aforementioned outlet 6A is carried out by means of a chain power transmission mechanism 50. That is, the power of the engine 6 is transmitted to the rear wheel 8 in the form of chain sprockets 51, 52 which are respectively mounted on the aforementioned output shaft 6A and the rear wheel 8 and the transmission chain 53 which is wound around these chain sprockets 51, 52.

[0024] The cylinder head 43 includes an inlet port 43A that opens on an upper surface of the cylinder head 43 communicating to the same time with the inner part of the cylinder 42A, and an exhaust port 43B opening on a lower surface of the cylinder head 43 while communicating with the inner part of the cylinder head 42A. Between the cylinder head 43 and the main structures 21, a regulator body 55 and an air filter 56 are installed which constitute an input system of the motor 6. The regulator body 55 is connected to the input port 43A and the filter of air 56 is connected to the front portion (an ascending side of the regulator body 55). In addition, an exhaust unit 60 constituting an exhaust system of the engine 6 is connected to the exhaust port 43B.

[0025] The exhaust unit 60, as shown in Figure 2, includes an exhaust pipe 61, a catalyst chamber 80 and a silencer 90, where the exhaust pipe 61 constitutes an exhaust pipe connecting to the port. of exhaust 43B and silencer 90. Figure 3 (A) is a view of the upper plane showing the exhaust pipe 61 and the catalyst chamber 80 and, Figure 3 (B) is a side view showing the exhaust pipe. Exhaust 61 and the catalyst chamber 80.

[0026] The exhaust pipe 61, as shown in Figure 3 (A) and Figure 3 (B), includes a front exhaust pipe 62 that is formed from a pipe. inclined and a rear exhaust pipe 63 extending substantially horizontally. With respect to the front exhaust pipe 62, as shown in Figure 4 and Figure 5, a diameter of a distal end of an inclined metal tube 62A is extended, a gasket 64 placed further inside than the portion of extended diameter and a collar 65 is mounted on the extended diameter portion. The front exhaust pipe 62 is connected to the head of the cylinder 43 by placing the collar 65 in contact with the cylinder head 43 with a packing that is not shown in the drawing placed between them and adjusting the gasket 64 to the cylinder head 43 through the use of bolts, thus allowing the front exhaust pipe 62 is connected to the exhaust port 43B. As shown in Figure 2 and Figure 3B, to house the front exhaust pipe 62 within a width of the engine 6, the front exhaust pipe 62 extends from the exhaust port 43B, is inclined in the vicinity of the cylinder head 43, and has a rear end thereof open to one side of the vehicle body (right side) below the cylinder head 43, and connects the catalyst chamber 80 to one end of the opening. With respect to the rear exhaust pipe 63, an inclined portion 63A is formed which slopes behind the catalyst chamber 80. Due to this inclined portion 63A, the rear exhaust pipe 63 can be positioned avoiding a draining bolt 6D which is clamped below the crankcase 41 of the motor 6.

[0027] The catalyst chamber 80, as shown in Figure 3 (A) and Figure 3 (B) includes a cylindrical case 81 which has an approximately cylindrical shape. The cylindrical case 81 is formed by the union of an upper case 81A and a lower case 81 B which are vertically divided by means of welding. The cylindrical case 81 includes an opening portion of the side surface 82 that opens projecting from a side surface of the cylindrical case 81. The opening portion of the side surface 82 corresponds to an exhaust passage of an inlet and an outlet of the catalyst chamber 80, a rear end of the exhaust tube 62 is inserted into and attached to the opening portion of the 82 lateral surface by means of welding. In this state, the opening portion of the side surface 82 forms an opening directed to the exhaust port 43B of the motor 6.

[0028] In a portion of the rear end of the cylindrical case 81, a port of the opening 83 is formed which is opens while reducing the diameter of the same. The portion of the opening 83 corresponds to another exhaust duct from the inlet and outlet port of the catalyst chamber 80, is fixed to a small diameter portion of a guide cover 84 having an approximately conical shape from the inside of the box, a catalyst 85 is fixed to a large diameter portion of the guide cover 84, and the rear exhaust pipe 63 is inserted and welded to the inside of the small diameter portion of the guide cap 84. As the catalyst 85 and the rear exhaust pipe 63 are coaxially positioned by means of the guide cap 84, the catalyst 85 is placed along an axis of the exhaust duct in the rear exhaust pipe 63. In addition, an upper surface and a lower surface (the upper case 81 A and the lower case 8 B) of the cylindrical case 81 are partially recessed to the internal part of the cylindrical case 81 thus forming a pair of upper and lower recessed portions 81 C, 81 D integrally. These recessed portions 81 C, 81 D surround the catalyst 85 from top to bottom thus holding the catalyst 85.

[0029] The catalyst 85 removes hydrocarbons, carbon monoxide, nitrogen oxide and the like contained in the exhaust gas by means of of an oxidation reaction or a reduction reaction. This catalyst 85 adopts a three-dimensional honeycomb catalyst which is constituted by the application of platinum, palladium, rhodium or similar to a porous honeycomb structural body. The catalyst 85 is placed in the cylindrical case 81 with a predetermined opening between the catalyst 85 and the internal walls (a front wall and a side wall) of the cylindrical case 81, and the portion of the opening of the above-mentioned lateral surface 82 is open within a width of the catalyst 85 in the direction of the length of the catalyst 85 and is formed in a position in which the portion of the opening 82 faces a side surface of the catalyst 85. According to this, the gas exhaust that is discharged from the engine 6 enters the interior part of the catalyst chamber 80 after passing through the aforementioned exhaust pipe 62 and, as indicated by the arrow in Figure 3 (A), flows towards the side surface of the catalyst 85. Subsequently, the exhaust gas enters the interior part of the catalyst 85 after passing through the opening around the catalyst 85. Here, the hydrocarbons, monoxide d carbon, nitrogen oxide and the like are removed by the oxidation reaction and the reduction reaction and, subsequently, the exhaust gas passes through the guide cap 84 and flows into the inside of the rear exhaust pipe 63. Here, instead of the three-dimensional honeycomb catalyst, a thermal tube carrying platinum, palladium, rhodium or the like in a die-cut tube can be used as the catalyst 85.

[0030] According to the constitution of this embodiment, such as described above, to the opening portion of the side surface 82 of the catalyst chamber 80, the front exhaust pipe 62 is connected which it constitutes the inclined tube that slopes from the exhaust port 33B and opens on the side of the vehicle body below the head of the cylinder 43 and therefore the catalyst chamber 80, as shown in Figure 1, it is located in the vicinity of a position just below the cylinder 42A. Accordingly, the catalyst chamber 80 can be placed in a free space below the cylinder head 43 and cylinder block 42, thus preventing the occurrence of the situation in which the lowest base height of the vehicle is reduced due to the catalyst chamber 80 or the occurrence of the situation in which the transverse angle of the vehicle is limited due to the catalyst chamber 80.

[0031] The rear exhaust pipe 63 extends rearward after passing under the motor 6 and the center of the body of the vehicle and, subsequently, inclines obliquely and upwards with respect to the vehicle body in the rear portion of the engine 6 and, subsequently, has a portion of the rear end thereof connected with a silencer 90. In this case, the rear exhaust pipe 63 passes below the engine 6 within a width of the engine 6 and has the rear end thereof connected to the silencer 90 and for therefore, the inclination of the rear exhaust pipe 63 is small so that the resistance of the exhaust can be reduced. At the same time, it is possible to avoid the occurrence of the situation in which the lower base height of the vehicle is reduced due to the rear exhaust pipe 63 or the occurrence of the situation in which the transverse angle of the vehicle is limited by the pipe. rear exhaust 63.

[0032] The silencer 90, as shown in Figure 1 and Figure 2, it includes a cylindrical body 100, and the cylindrical body 100 is formed by a first portion of the muffler 91 that is positioned between the crankcase 41 and the rear wheel 8, a second portion of the muffler 92 extending projecting to one side (right side) of the rear wheel 8 and is positioned in this portion, and a connecting portion 93 integrally connecting these portions of the muffler 91, 92 with smooth curves.

[0033] Figure 6 (A) is a view of the plane of the muffler 90, and Figure 6 (B) is a side view of the muffler 90. The cylindrical body 100, as shown in Figure 6 (A) and Figure 6 (B), is formed by the vertical union of the boxes 100A, 100B that are vertically divided by welding. The reinforcements 101, 102 are respectively mounted on the front and rear portions of the upper case 100A of the cylindrical body 100 and the cylindrical body 100 has a support on the body structure of the vehicle 2 by means of these reinforcements 101, 102. , to the lower case 100B, a plug 103 is joined by welding in a position corresponding to a lower surface of the connecting portion 93. The plug 103 is in contact with a portion of the plug 30C of the main leg 30 when the main leg 30 is rotated toward the storage position thereby functioning as a plug for the main leg 30.

[0034] In the aforementioned constitution, the muffler 90 includes the first portion of the muffler 91 which is positioned between the crankcase 41 and the wheel rear 8, the second portion of the muffler 92 which is positioned projecting to the side (right side) of the rear wheel 8, and a connecting portion 93 that integrally connects these portions of the muffler 91, 92. Accordingly, a space capacity required for the muffler 90 can be distributed in a front side and a side side of the rear wheel 8. Accordingly, in comparison with the constitution in which the silencer is adapted with the same space capacity between the crankcase 41 and the rear wheel 8, it is not necessary to increase the base of the wheel thus realizing a miniature size of the vehicle.

[0035] Figure 7 (A) is a view of the plane showing the lower case 100B of the silencer 90 together with the peripheral constitution thereof, and Figure 7 (B) is a side view of the silencer 90 together with the peripheral constitution . In the lower case 100B, as shown in Figure 7 (A) and Figure 7 (B), a portion of the opening 1 10 is formed in a front end wall 100 (B) 1 obliquely in the direction of the front and down, as shown in Figure 8, a connecting pipe 120 of the cylindrical exhaust pipe is mounted obliquely in the portion of the opening 1 10, and the rear exhaust pipe 63 is connected to the connecting pipe 120 of the exhaust pipe. Due to this constitution, the rear exhaust pipe 63 and the connecting pipe 120 of the exhaust pipe communicate with each other. As shown in Figure 8, a plurality of open holes 120A are formed in a peripheral surface of the connection pipe 120 of the exhaust pipe, and at the same time, an opening formed in a rear end of the connection pipe 120 of the pipe Exhaust is closed by means of a plate 120B (see Figure 7 (A)). Due to this constitution, the exhaust gas discharged from the rear exhaust pipe 63 is discharged from the aforementioned plurality of open holes 120A and expands inside a chamber (an expansion chamber) R1 of the first portion of the muffler 91, and the exhaust gas in the inside the chamber flows into the second portion of the muffler 92.

[0036] The second portion of the muffler 92 is divided into three expansion chambers (a first expansion chamber R1A communicated with the expansion chamber R1, a second expansion chamber R2 , a third expansion chamber R3) by means of a first partition wall 130 and the second partition wall 131. As shown in Figure 7 (A), a first communication tube 132 communicating with the first chamber of expansion R1A is fixed to the first partition wall 130 in a penetrating manner, and the first communication tube 131 communicates with the second expansion chamber R2 through the third expansion chamber R3 and the second partition wall 131. A second communication tube 133 is fixed to the second partition wall 131 in a position in which the second communication tube 133 does not interfere with the first communication tube 132, to be more specific, in a position displaced towards the outside of the vehicle from the first communication tube 132 in a penetrating manner, and the second expansion chamber R2 and the third expansion chamber R3 communicate with each other due to this second communication tube 133.

[0037] In addition, to the second wall of division 131, a third tube is fixed communication 134 communicating with the third expansion chamber R3 in a penetrating manner in a position in which the third communication tube 134 does not interfere with the aforementioned first and second communication tubes 132, 133, ie in a position in which the third communication tube 134 is moved to the side of the vehicle body from the first communication tube 132. The third communication tube 134 traverses the second expansion chamber R2 and penetrates the rear end wall 100B2 of the lower case 100B. Because of this constitution, the third communication tube 134 functions as a back tube that discharges the exhaust gas inside the muffler 90 towards the outside of the muffler 90. The third communication tube 134, as shown in Figure 7 (B) , is inclined obliquely in the downward direction towards a rear side of the vehicle body and, at the same time, as shown in Figure 7 (A), the second partition wall 131 penetrates with the inclination that is inclined obliquely in the downward direction towards the side of the vehicle body, and as shown in Figure 9, penetrates a rear end wall 100B2 of the lower case 100B, and is fixed to the second partition wall 131 and the rear end wall 100B2 by welding. Due to this constitution, the rear tube is positioned obliquely as in the oblique external direction with respect to the body of the vehicle and therefore, the obstruction of the exhaust gas can be reduced because the spots on the rear portion of the body of the vehicle attributed to the exhaust gas are also reduced.

[0038] Due to the structure of the aforementioned silencer, the gas of The exhaust that is discharged from the engine 6 is purified by the catalyst chamber 80 which is placed in the intermediate portion of the exhaust pipe 61 and subsequently enters the interior part of the silencer 90. As indicated by an arrow in Figure 7 (A), the exhaust gas enters the interior of the expansion chamber R1 of the first portion of the silencer 91 and, subsequently, enters the first expansion chamber R1A in the interior part of the second portion of the muffler 92, and enters the second expansion chamber R2 after passing through the first communication tube 132. Subsequently, the exhaust gas reverses the flow direction thereof and enters the third expansion chamber R3 after passing to through the second communication tube 133. Subsequently, the exhaust gas reverses the direction of flow thereof and is discharged towards the exterior of the silencer 90 after passing through the third tube of communication 134. In this manner, the exhaust gas expands in the expansion chamber R1 of the first portion of the muffler 91 and, subsequently, the flow of the exhaust gas is reversed in the internal part of the second portion of the muffler 92 and , subsequently, the exhaust gas expands in the plurality of expansion chambers R2, R3. Accordingly, it is possible to secure the capabilities of the large muffler of the first portion of the muffler 91 and the second portion of the muffler 92 thereby reducing exhaust sound sufficiently.

[0039] In addition, a base shape of the second portion of the muffler 92 that is positioned on one side of the rear wheel 18, as shown in Figure 10 to Figure 13, is formed in a sloping inclined configuration. in the upwardly substantially oblique direction towards a right side of the vehicle body from the side of the vehicle body (rear wheel side 8) substantially along a right inclined surface LO of the vehicle body connecting the dots of ground contact of the front and rear wheels and the lower portion of the outer end of the main stirrup 36. Due to this constitution, the capacity of the second portion of the silencer 92 can be sufficiently guaranteed while avoiding the occurrence of the situation in which the transverse angle of the vehicle is limited by the second portion of the muffler 92 or the occurrence of the situation in which the lowest base height of the vehicle is reduced.

[0040] In this embodiment, the portion of the opening of the side surface 82 that constitutes one of the exhaust conduits corresponding to the inlet and outlet of the catalyst chamber 80 is formed in the side wall of the chamber of the catalyst. catalyst 80. Accordingly, the front exhaust pipe 62 constituting the inclined pipe extending from the exhaust port 43B and inclined can be connected to the aforementioned opening portion of the side surface 82 and therefore , compared to the structure of the catalyst arrangement presenting the catalyst chamber in the straight line portion of the exhaust pipe, the catalyst chamber 80 can be placed in a compact manner. In addition, the degree of freedom in the arrangement in the catalyst chamber 80 and the degree of freedom in the design of the exhaust pipe can be improved. In this way, according to the constitution of this embodiment, the catalyst chamber 80 can be placed in a compact manner in the space below the cylinder 42A, that is, in the space below the block of the cylinder 42 and the head of the cylinder 43, as well as in the space facing the crankcase 41.

[0041] In addition, the portion of the aforementioned side surface opening 82 is positioned in such a way that it faces the side surface of the catalyst 85 and therefore, the catalyst chamber 80 can be placed near the cylinder head 43 (near the front side of the engine) whereby it is possible to easily install the catalyst chamber 80 in the space below the cylinder 42A. In addition, the exhaust gas from the engine 6 passes through the catalyst 85 after turning around the periphery of the catalyst 85 and therefore, the flow velocity of the exhaust gas passing through the catalyst can be suppressed. In addition, the catalyst 85 is positioned along the axis of the exhaust duct of the rear exhaust pipe 63 and therefore, the catalyst chamber 80 can have a miniature size.

[0042] In addition, the opening portion of the side surface 82 of the catalyst chamber 80 opens toward the exhaust port 43B and therefore, the temperature of the catalyst 85 easily reaches the activation temperature due to the heat of the catalyst. high temperature exhaust gas from the exhaust port 43B, whereby, at the moment of driving a cold engine, the catalyst 85 can be activated in a relatively short period of time immediately after starting the engine 6 and at the same time , the water from the outside hardly penetrates inside the portion of the opening of the lateral surface 82, thus preventing the catalyst 85 from splashing with water. In addition, according to the constitution of this embodiment, the recessed portions 81 C, 81 D are formed by lowering the upper portion and the lower portion of the cylindrical housing 81 of the catalyst chamber 80 and the catalyst 85 is supported by these recessed portions 81 C, 81 D and therefore not an additional fixing member is necessary to fix the catalyst 85, whereby the production cost can be reduced. In addition, the catalyst chamber 80 is formed by vertically joining two boxes 81 A, 81 B and therefore, the catalyst 85 can be held by joining the boxes 81 A, 81 B thereby facilitating the assembly of the catalyst 85.

[0043] , in this embodiment, the muffler 90 includes the first portion of the muffler 91 which is positioned between the engine 6 and the rear wheel 8, the second portion of the muffler 92 which is positioned projecting to the side (right side) of the wheel rear 8, and the connecting portion 93 integrally connecting these portions of the muffler 91, 92 and therefore, the necessary capacity for the muffler 90 can be dispersed to the front side and the side side of the rear wheel 8, thus not It is necessary to lengthen the base of the wheel thus making a miniature size of the vehicle. In addition, the rear exhaust pipe 63 passes below the center of the vehicle body, is inclined obliquely in the upper direction with respect to the vehicle body at a rear portion of the engine 6, and is connected to the first portion. of the silencer 91. Accordingly, the inclination of the exhaust pipe is not increased and therefore, the exhaust pipe can be easily formed, high accuracy can be guaranteed easily and the exhaust resistance can be reduced.

[0044] In addition, the aforementioned silencer 90 is formed by vertically joining the upper case 100A and the lower case 100B and therefore, the manufacture and assembly of the silencer 90 are facilitated thereby improving productivity. In addition, the rear exhaust pipe 63 is inserted into the connecting portion of the first portion of the muffler 91 in the oblique upper direction from the front lower side and therefore, the inclination of the rear exhaust pipe 63 is not large, whereby the resistance of the exhaust can be reduced and, at the same time, the rear exhaust pipe 63 can be connected to the first portion of the muffler 91 in a position in which the rear exhaust pipe 63 does not interfere with the welding cords ( connecting line) of the upper and lower boxes 100A, 00B. In addition, the plug 103 of the main leg 30 is positioned in the connecting portion 93 connecting the first portion of the muffler 91 and the second portion of the muffler 92 and therefore, the plug 103 can also function as a reinforcing member that It reinforces the connection between the aforementioned muffler portions 91, 92. Additionally, the rear tube is positioned in the second portion of the muffler 92 in such a state that the rear tube is directed in the oblique downward direction as well as in the outward direction oblique and, therefore, the complications of the exhaust gas can be reduced thereby reducing the spots in the rear portion of the vehicle body attributed to the exhaust gas.

[0045] (Second embodiment) Figure 14 is a side view showing a catalyst chamber 180 according to a second embodiment together with a motor 6. Furthermore, Figure 15 (A) is a view of the plane of an exhaust pipe 161 and the chamber of the catalyst 180, Figure 15 (B) is a side view of the exhaust pipe 161 and the catalyst chamber 180, Figure 16 is a view of the exhaust pipe 161 and the catalyst chamber 180 as seen from one side front, and Figure 17 is a longitudinal sectional view of the exhaust pipe 161 and the catalyst chamber 180. Here, in the second embodiment, the identical parts to the parts of the first embodiment are given the same numbers and their repeated explanation is omitted. As shown in Figure 14, the engine 6 is a horizontal single-cylinder engine (horizontal engine) that includes a crankcase 41, a cylinder block 42 that is connected to a front portion of the crankcase 41, a cylinder head. 43 which is connected to a front portion of the cylinder block 42, and an upper cover 44 which is connected to a front portion of the cylinder head 43, where a cylinder is placed horizontally on the inside of the cylinder block 42. [0046 ] An exhaust unit 60 constituting an engine exhaust system 6 includes an exhaust pipe 161, a catalyst chamber 180 and a silencer 190 described later. The exhaust pipe 161 includes a front exhaust pipe 162 that connects the engine 6 and the catalyst chamber 180, and a rear exhaust pipe 163 that connects the catalyst chamber 180 and the muffler 90. The front exhaust pipe 162 is an inclined tube that is inclined from such that it fits within a width of the motor 6. To be more specific, as shown in Figure 14 and Figure 16, the front exhaust pipe 162 extends downwardly from an exhaust opening of the cylinder head. 43 on a front right side of the catalyst chamber 180, extends backward as it is tilted and winds around the catalyst chamber 180 to a left side of the catalyst chamber 180, and opens to one side of the body of the catalyst. vehicle (right side) below the cylinder block 42. The catalyst chamber 180 is connected to an open end of the exhaust pipe 162.

[0047] The rear exhaust pipe 163 extends, as shown in Figure 14 towards back down from the crankcase 41 from a rear end of the catalyst chamber 180. The rear exhaust pipe 163 changes, as shown in Figure 15 (B), a transverse shape thereof from a perfect circular shape to a shape elliptical elongated laterally and, later, returns to the transverse form from the elliptical shape elongated laterally to the perfect circular shape again. In addition, these transverse shapes have substantially the same cross-sectional area. The reason why the transverse shape of the rear exhaust pipe 163 changes in this way is as follows. As shown in Figure 14, a lower surface of the crankcase 41 includes a front sloped surface 41 A that is inclined back and down from a connecting portion between the crankcase 41 and the cylinder block 42, a horizontal surface 41 B extending backward from a lower end of the front inclined surface 41 A in a manner substantially horizontal, and a rear inclined surface 41 C that slopes back and up from a rear end of the horizontal surface 41 B. Under this constitution, when the rear exhaust pipe 163 is formed to have a perfect circular cross-sectional shape to along the entire length, in order to ensure a sufficient cross-sectional area of the rear exhaust pipe 163, the case may arise that the rear exhaust pipe 163 is placed in a position below a horizontal surface 4 B which constitutes a lower surface of the crankcase 41 and lower than a minimum total height which is the objective of the rear exhaust pipe 163.

[0048] In view of the foregoing, in the rear exhaust pipe 163 of this embodiment, to change the height of the pipe rear exhaust 163 (a diameter of the rear exhaust pipe 163 in the vertical direction of the vehicle body) along the front inclined surface 41 A, the horizontal surface 41 B and rear inclined surface 41 C, that is, along the inclination of a lower surface of the crankcase 41, the transverse shape of the rear exhaust pipe 163 changes from the perfect circular shape to the laterally elongated elongated shape and, subsequently, of the elliptical shape elongated laterally to the perfect circular shape once again ensuring in this way the sufficient minimum base height while maintaining the substantially uniform exhaust resistance of the rear exhaust pipe 163.

[0049] Next , the catalyst chamber 180 is explained in detail. The catalyst chamber 180, as shown in Figure 14, is positioned below the cylinder block 42 of the engine 6 and the crankcase 41. The camera of Catalyst 180 includes a portion of the catalyst shell 180A that houses a catalyst 85 therein and a protruding portion 180B projecting to the engine 6 side (upper side of the vehicle body) from the portion of the catalyst shell 180A along the cylinder block 42 and the crankcase 41. As shown in Figure 15 (A) and Figure 15 (B), the catalyst chamber 180 includes a cylindrical case 181 that is integrally formed by the accommodated portion of the catalyst 180A and the protruding portion 180B, and the cylindrical case 181 is formed by joining a left case 181 A and a right case 181 B which are respectively formed in a substantially bowl configuration with each other.

[0050] On a side surface of the protruding portion 180B of the cylindrical case 181, ie, on an upper portion of a side surface of the left case 181 A, as shown in Figure 16, a portion of the opening of the side surface 182 that opens in the width direction of the vehicle body (leftward direction of the vehicle body). The opening portion of the side surface 182 corresponds to an exhaust duct that constitutes either an inlet and an outlet of the catalyst chamber 80, and a rear end of the front exhaust pipe 62 is inserted and attached to the portion of the opening of the side surface 182 by means of a weld.

[0051] In a portion of the rear end of the accommodated portion of the catalyst 180A of the cylindrical case 181, as shown in Figure 17, a portion of the opening 183 that opens in the backward direction. The opening portion 183 corresponds to an exhaust duct constituting another of the inlet and outlet of the catalyst chamber 80. The rear exhaust pipe 63 is attached to the portion of the opening 183 by means of a weld in a state in which a front end of the rear exhaust pipe 63 is inserted into the interior of the case 181, and the catalyst 85 is fixed to the front end portion from the interior of the case 181. Due to this constitution , a catalyst shaft 85 is aligned with the direction of the duct of the rear exhaust pipe 163 and therefore, the catalyst 85 and the rear exhaust pipe 63 are placed coaxially whereby the catalyst 85 is located throughout of an exhaust duct shaft of the rear exhaust pipe 163 and, at the same time, the front exhaust pipe 162 can be opened within a width of the catalyst 85 in the direction of the length.

[0052] Here, the constitution that discharges an exhaust gas from a motor to a catalyst in the internal part of the chamber of a catalyst has the possibility of generating vibrations of the catalyst or something similar. On the contrary, this embodiment, as described above, forms the protruding portion 180B which is inclined from the accommodated portion of the catalyst 180A of the catalyst chamber 180, and connects the front exhaust pipe 162 to the portion of the opening of the lateral surface 182 of the protruding portion 180B and therefore, the exhaust conduit from the engine 6 communicates with the catalyst chamber in a position that is off-center from the catalyst 85.

[0053] Accordingly, the exhaust gas from the engine 6, as indicated by a wavy arrow G in Figure 16, is not discharged to the catalyst 85 but rather discharges to an inner wall 180B1 of the protruding portion 180B of the catalyst chamber 180, collides on the inner wall 180B1 and, subsequently, flows towards the catalyst 85 and passes through the catalyst 85. Accordingly, the flow velocity of the exhaust gas is reduced due to the gas shock from the catalyst. leakage in the inner wall 180B1 and, at the same time, due to the expansion of the exhaust gas in the inner part of the protruding portion 180B and, subsequently, the exhaust gas passes through the catalyst 85. According to this, it is it is possible to suppress with certainty the flow velocity of the exhaust gas passing through the catalyst 85 thus avoiding the aforementioned generation of vibrations.

[0054] Figure 18 (A) is a plan view of a silencer 190 and Figure 18B is a side view of the muffler 190. The muffler 190 includes a cylindrical body 200 that is formed by vertically joining the boxes 200A, 200B that are divided in two vertically. The cylindrical body 200 is formed by a first portion of the muffler 191 which is positioned between the crankcase 41 and the rear wheel 8, a second portion of the muffler 192 extending to one side (right side) of the rear wheel 8 in the form of projection and is positioned on the side of the rear wheel 8, and a connecting portion 193 connecting these portions of the muffler 191, 192 along a light curve line. The silencer 190, in the same manner as the first embodiment, is configured in such a way that the capacity required by the muffler 190 is dispersed towards the front and the rear wheel side 8. Accordingly, compared to the constitution in which a muffler with the same capacity is available between the crankcase 41 and the rear wheel 8, it is not It is necessary to lengthen the base of the wheel and therefore, the vehicle can have a miniature size.

[0055] Figure 19 (A) is a plan view of a lower case 200B of the silencer 190 in which the peripheral constitution of the lower case 200B is also shown., and Figure 19 (B) is a side view of the lower case 200B and the peripheral constitution. A connecting pipe of the cylindrical exhaust pipe 120 is mounted on a front portion of the lower case 200B in a state in which the connection pipe 120 opens obliquely in the direction towards the front and downwards. A rear exhaust pipe 163 is connected to the connecting pipe of the exhaust pipe 120. An exhaust gas that is discharged from the rear exhaust pipe 163 is discharged from a plurality of holes in the opening 20A and expands inside the exhaust pipe. a first expansion chamber (chamber) R1 of the first portion of the silencer 191 and the exhaust gas in the interior of the expansion chamber R1 is flowed to the second portion of the silencer 192. The second portion of the silencer 192 is divided in three expansion chambers (a first expansion chamber R1A communicating with the expansion chamber R1, a second expansion chamber R2, a third expansion chamber R3) through a first partition wall 130 and a second partition wall. division 131. A first communication tube 132, a second communication tube 133 and a third communication tube 134 which also it functions as a back tube are fixed to the respective expansion chambers R1A, R2 and R3.

[0056] Due to the aforementioned structure, the exhaust gas discharged from the engine 6 is purified by the catalyst chamber 180 and, subsequently, enters the internal part of the silencer 190. Then, as indicated in Figure 19 (A) and (B), the exhaust gas enters the expansion chamber R1 of the first portion of the silencer 191 and, subsequently, enters the first expansion chamber R1A in the interior part of the second portion of the silencer 192 and , then, it enters the second expansion chamber R2 through the first communication tube 132. Then, the exhaust gas reverses a flow thereof and enters the third expansion chamber R3 through the second communication tube 133 and, therefore, it changes the direction of flow thereof and is discharged to the outside of the muffler 190 through the third communication tube 134. In this embodiment, as shown in Figure 19 (A), and the Figure 19 (B ), as a plurality (three in this embodiment) of communication tubes 132, 133, 134 fixed to the second partition wall 131 are positioned longitudinally, the space of the arrangement for these communication tubes 132, 133, 134 may narrowing in width and the degree of freedom can be improved with respect to the shape of the silencer 190.

[0057] In this embodiment, the exhaust pipe is connected to the lateral surface of the protruding portion 180B of the catalyst chamber 180. front 162 that corresponds to an exhaust duct. Agree with this, In addition to the beneficial effects acquired by the first embodiment, the exhaust conduit from the engine 6 communicates with the catalyst chamber 180 in the off-center position from the catalyst 85 in the catalyst chamber 180 and is therefore possible allowing the exhaust gas to flow to the catalyst 85 after reducing the flow velocity of the exhaust gas in the interior of the catalyst chamber 180. Accordingly, generation of vibrations of the catalyst 85 or a similar situation can be prevented. .

[0058] In addition, the aforementioned protruding portion 180B is inclined towards the motor side 6 along the cylinder block 42 and the crankcase 41 and therefore, the protruding portion 180B can be placed in a dead space defined between the block of the cylinder 42 and the crankcase 41, thereby improving the efficiency of the arrangement of the protruding portion 180B. In addition, the exhaust pipe 162 is connected to the catalyst chamber 180 after wrapping around a periphery of the catalyst chamber 180 thereby softening the flow of the exhaust gas.

[0059] Although the invention has been explained in conjunction with one embodiment of the present, it is apparent that the invention is not limited to this embodiment. For example, catalyst chambers 80, 180 can be formed with a tube-forming product. Furthermore, in the respective aforementioned embodiments, the explanation is made with respect to a case in which the exhaust gas from the engine 6 is introduced from the opening portions of the lateral surface 82, 182 of the catalyst chamber. 80, catalyst 85 is passed into the interior of the catalyst chamber 80 and discharged from the portions of the opening 83, 183 at the rear end of the catalyst chambers 80, 180. However, the exhaust gas can be caused to flow in the opposite direction. That is, the exhaust gas from the engine 6 can be introduced into the catalyst chamber 80, 180 from the opening portions 83, 183 of the catalyst chambers 80, 180, passed through the catalyst 85, and discharge from the opening portion of the side surface 82. Further, in the aforementioned embodiment, the explanation is made with respect to a case in which the invention is applied to the motorcycle in which the motor of a single horizontal cylinder is mounted in which the cylinder is placed horizontally. However, the invention is not limited to this embodiment and can be broadly applied to the motorcycle on which a vertical motor is mounted where the cylinder is installed vertically or an engine with multiple cylinders therein. [Brief Description of the Illustrations]

[0060] [Figure 1] A side view of a motorcycle according to a first embodiment. [Figure 2] A view of the upper plane showing the body structure of a motorcycle vehicle together with the peripheral constitution. [Figure 3] (A) is a view of the plane of an exhaust pipe and a catalyst chamber, and (B) is a side view of the exhaust pipe and catalyst chamber. [Figure 4] A view showing a front exhaust pipe along with the catalyst chamber. [Figure 5] A transverse view taken along a line V - V in Figure 4. [Figure 6] (A) is a view of the plane of a muffler, and (B) is a side view of the muffler. [Fig. 7] (A) is a view of the plane showing a lower case of the muffler together with the peripheral constitution, and (B) is a side view of the lower case of the muffler together with the peripheral constitution. [Figure 8] A view showing a pipe connecting the exhaust pipe together with the peripheral constitution. [Figure 9] A view showing a third communication tube together with the peripheral constitution. [Figure 10] A cross-sectional view taken along a line X-X in Figure 7 (B). [Figure 1 1] A cross-sectional view taken along a line XI-XI in Figure 7 (B). [Figure 12] A cross-sectional view taken along a line XII-XII in Figure 7 (B). [Figure 13] A transverse view taken along a line XIII -XIII in Figure 7 (B). [Figure 14] A side view showing a catalyst chamber according to a second embodiment together with a motor. [Figure 15] (A) is a view of the plane of an exhaust pipe and a catalyst chamber, and (B) is a side view of the exhaust pipe and the catalyst chamber. [Figure 16] A view of the exhaust pipe and the catalyst chamber displayed from a front side.

[Figure 17] A cross-sectional view taken along a line XVII -XVII in Figure 15 (A). [Figure 18] (A) is a view of the plane of a silencer, and (B) is a side view of the silencer. [Fig. 19] (A) is a view of the plane showing a lower case of the muffler together with the peripheral constitution, and (B) is a side view of the lower case of the muffler together with the peripheral constitution. [Description of Reference Numbers and Signs]

[0061] 1: motorcycle 2: vehicle body 6: engine (horizontal motor) 30: main leg 31: side leg 42A: cylinder 43A: input port 43B: exhaust port 60 : exhaust unit 61, 161: exhaust pipe 62, 162: front exhaust pipe 63, 163: rear exhaust pipe 80, 180: catalyst chamber 82, 182: portion of the opening of the side surface 83, 183: opening portion 85: catalyst 90, 190: muffler 91, 191: first muffler portion 92, 192: second muffler portion 93, 193: connecting portion 103: plug 180A: accommodated portion of catalyst 180B: protruding portion LO: inclined surface to the right of the vehicle body R1, R1A, R2, R3: expansion chamber.

Claims

CLAIMS [Claim 1] A catalyst arrangement structure of a motorcycle having a catalyst chamber in an intermediate portion of an exhaust pipe that connects an exhaust port of a cylinder head and a muffler, where outside of the ducts of exhaust corresponding to an inlet and outlet of the catalyst chamber, one axis of a catalyst is aligned with the direction of the duct of an exhaust duct, and another exhaust duct is open within a width in the direction of the length of the catalyst. [
Claim 2] A structure of the catalyst arrangement of a motorcycle according to claim 1, wherein the catalyst is positioned along an axis of an exhaust duct, and an opening formed in a side surface of the chamber of the catalyst constituting an opening of another exhaust duct is facing a side surface of the catalyst. [
Claim 3] A structure of the catalyst arrangement of a motorcycle according to claim 2, wherein the opening formed in the lateral surface of the catalyst chamber is an opening that is directed towards the exhaust port. [
Claim 4] A structure of the catalyst arrangement of a motorcycle according to any of claims 1 to 3, wherein the catalyst is placed in a recessed portion of the catalyst chamber.
[Claim 5] A structure of the catalyst arrangement of a motorcycle according to claim 1, wherein another exhaust conduit communicates with the catalyst chamber in an off-center position from a catalyst in the catalyst chamber.
[Claim 6] A structure of the catalyst arrangement of a motorcycle according to claim 5, wherein a protruding portion that slopes towards an engine along a cylinder block of the engine and a crankcase is formed in the chamber of the catalyst, and another exhaust conduit communicates with the protruding portion.
[Claim 7] A structure of the catalyst arrangement of a motorcycle according to claim 5 or claim 6, wherein another exhaust conduit is formed within a configuration that is wrapped around a periphery of the catalyst chamber and communicates with a side surface of the catalyst chamber.
[Claim 8] A structure of the catalyst arrangement of a motorcycle according to any of claims 1 to 7, wherein the catalyst chamber is positioned below a cylinder of a horizontal motor. The rear seat bracket 39 is shown in a condition such that the rear seat bracket 39 is bent to one side of the vehicle body. [Designation of the Document] Summary [Summary] [Problem] Offer the structure of the catalyst arrangement of a motorcycle that presents a catalyst chamber in a compact manner. [Resolution Media] Outside the exhaust ducts 62, 63 corresponding to an inlet and outlet of a catalyst chamber 80, an axis of a catalyst 85 is aligned with the duct direction of an exhaust duct 63, and another Exhaust duct 62 opens within a width in the direction of the length of the catalyst 85. [Selected Illustration] Figure 3.