Title of Invention

AN INTAKE SYSTEM FOR A POWER UNIT SWING TYPE SCOOTER VEHICLE

Abstract

[Object] To provide an intake system for a scooter-type vehicle in which an intake chamber of the intake system is provided on a transmission case of a unit swing type power unit, which system is capable of preventing permeation of water droplets or dust splashed up or flied up by a rear wheel into an intake port of the intake chamber. [Solving Means] An intake system for a power unit swing type scooter-type vehicle in which a rear wheel 12 is supported on the rear portion of a power unit composed of an engine and a transmission case and the power unit is swingably supported by a vehicular body, characterized in that an air cleaner 41 is arranged on the transmission case of the power unit, and an intake chamber 31 is connected to the air cleaner 41; and the air cleaner 41 is offset to one side from a center line C of the vehicular body, and an intake port 34 of the intake chamber 31 is arranged opposite to the air cleaner 41 with respect to the center line C of the vehicular body.

Full Text

[Detailed Description of the Invention] [0001] [Technical Filed of the Invention] The present invention relates to an intake system for a power unit swing type scooter-type vehicle, which intake system includes an intake chamber and an air cleaner both supported by a power unit. [0002] [Related Art] Japanese Utility Model Laid-open No. Sho 64-22692 discloses a power unit swing type scooter-type vehicle in which a rear wheel is supported on the rear portion of a power unit including a transmission case integrated with an engine and the power unit is swingably supported by a vehicular body, wherein an air cleaner and an intake chamber are supported on the transmission case of the power unit. [0003] The outline of the above technique will be described with reference to Fig. 7. Fig. 7 is a plan view illustrating the intake system disclosed in the above document. In this figure, parts shown in the figure of the above document are arranged inversely on the right and left sides for a clearer understanding of the following description of the present invention. The drawing should be viewed in the orientation of symbols. The front, rear, left and right sides, which are respectively denoted by symbols Fr, Rr, L and R in the figure, are based on the direction viewed by the driver. On the left side of a rear wheel 101 is arranged an air cleaner 102 including a main body 102b, a cover 102a, and an element 102c interposed therebetween. In front of the rear wheel 101 is arranged an intake chamber 105 with its intake port 106 opened in front of the rear wheel 101 and also substantially on the center line of the vehicular body. The inside of the air cleaner 102 is partitioned, by means of the element 102c, into an outer dirty side 102d and an inner clean side 102e. A connecting pipe 104 having a specific length extends rearward from one side of the intake chamber 105 and is connected to the outer dirty side 102d of the air cleaner 102. The inner clean side 102e is connected to a carburetor (not shown) constituting a fuel supply system via a connecting tube 103. In the figure, reference numeral 107 denotes a rear cushion unit. The inner wall portion of the main body 102b is in part curved largely outward to form a recess 102f for containing the rear cushion unit 107. [0004] [Problems to be Solved by the Invention] In the above-described related art intake system, outside air flows as shown by arrows of Fig. 7. To be more specific, outside air is introduced in the intake chamber 105 from the intake port 106 opened in the front surface of the intake chamber 105, passing through the connecting pipe 104, and flows in the dirty side 102d, i.e., outer chamber of the air cleaner 102. Then, the air passes through the element 102c, and flows in the clean side 102e. The air thus cleaned is sucked in the carburetor via the connecting tube 103. The above related art intake system, however, has a problem. Since the intake chamber 105 is arranged with its intake port 106 located on the center line of the vehicular body and also in front of the rear wheel 101, the intake port 106 is liable to be affected by the rear wheel during running of the vehicle. Upon running of the vehicle in the rain, rain water may be splashed by the rear wheel up to the intake port 106, giving rise to an inconvenience that dirty water droplets may permeate in the intake chamber 105 through the intake port 106. Even upon running of the vehicle in fine weather, since the intake port of the intake chamber 105 is positioned on the extension of the rear wheel, dust flied up by the rear wheel is liable to permeate in the intake chamber 105 through the intake port, giving rise to an inconvenience that the service life of the element 102c is shortened. [0005] The related art system has another problem. Since the intake chamber 105 is arranged apart in front of the rear wheel 101 and is connected to the air cleaner 102 via the connecting pipe 104, the longitudinal length of the entire intake system becomes large. This is disadvantageous in terms of space layout in the case of arranging the intake system on the power unit which includes the engine and carburetor and supports the rear wheel via the rear cushion unit interposed between the body and the power unit. Also since the intake chamber 105 is connected to the air cleaner 102 via the connecting pipe 104, the number of assembling steps is increased as well as the number of parts is increased. [0006] The present invention has been made to solve the above problems in arrangement of an intake system on a transmission case of a power unit. An object of the present invention is to provide an intake system for a scooter-type vehicle in which an intake chamber of the intake system is arranged on a transmission case of a power unit and in front of a rear wheel, which is capable of preventing permeation of water droplets or dust splashed up or flied up by the rear wheel into the intake chamber to thereby allowing suction of air less mixed with water droplets or dust; arranging the intake system in a limited small space while allowing effective air intake at a high efficiency, which is advantageous in terms of space layout in the case of arranging the intake system on the transmission case of the power unit; and reducing the number of assembling steps as well as the number of parts. [0007] [Means for Solving the Problems] To achieve the above object, according to an invention described in claim 1, there is provided an intake system for a power unit swing type scooter-type vehicle in which a rear wheel is supported on the rear portion of a power unit composed of an engine and a transmission case and the power unit is swingably supported by a vehicular body, characterized in that an air cleaner is arranged on the transmission case of the power unit, and an intake chamber is connected to the air cleaner; and the air cleaner is offset to one side from a center line of the vehicular body, and an intake port of the intake chamber is arranged opposite to the air cleaner with respect to the center line of the vehicular body. [0008] With this configuration, since the air cleaner is offset to one side from the center line of the vehicular body and the intake port of the intake chamber is arranged opposite to the air cleaner with respect to the center line of the body, the intake port is largely apart from the rear wheel by means of which water droplets are splashed up or dust is flied up, with a result that outside air less mixed with water droplets or dust can be introduced in the intake chamber from the intake port. Also since the intake port of the intake chamber is not required to be arranged apart in front of the rear wheel, the longitudinal length of the entire intake system can be reduced, leading to miniaturization of the intake system. Further, since the intake chamber is directly connected to the air cleaner, it is possible to eliminate the necessity of provision of any connecting pipe, and hence to reduce the number of assembling steps as well as the number of parts. [0009] According to an invention described in claim 2, in addition to the configuration of the invention described in claim 1, the air cleaner includes right and left cases dividedly arranged right and left in the width direction of the vehicular body with an element put therebetween, wherein an inner space and an outer space, which are partitioned from each other by the element and right and left cases, are taken as a dirty side and a clean side, respectively. With this configuration, since the inner and outer sides of the air cleaner in the width direction of the vehicular body are taken as the dirty side and the clean side, respectively, it is possible to eliminate the necessity of adopting the related art configuration in which the connecting tube is unreasonably bent outward from the inner clean side to be connected to the front carburetor, and to connect the outer clean side to the front carburetor on the same side. Accordingly, it is possible to arrange the air cleaner and the intake chamber near the central portion in the width direction of the vehicular body while suppressing the dimension of the air cleaner in the width direction by suppressing the amount of the entire air cleaner swelled outward in the width direction of the vehicular body. [0010] According to an invention described in claim 3, in addition to the configuration of the invention described in claim 1, the intake chamber is supported by the transmission case integrated with the engine, and a fender for the rear wheel is formed integrally with the intake chamber. With this configuration, since the fender for the rear wheel is formed integrally with the intake chamber, it is possible to reduce the number of assembling steps as well as the number of parts. [Brief Description of the Drawings] [Fig. 1] A side view showing the appearance of a scdbter-type vehicle including an intake system of the present invention. [Fig. 2] A plan view of Fig. 1. [Fig. 3] A side view showing the appearance of the intake system. [Fig. 4] A plan view of essential portions of the intake system, with parts partially cutaway. [Fig. 5] An exploded plan view of the intake system, wherein an air cleaner is shown in a cross-sectional plan view. [Fig. 6] A plan view showing a positional relationship between a rear wheel and the intake system, wherein the air cleaner is shown in a cross-sectional plan view and the flow of air is shown by arrows. [Fig. 7] A cross-sectional plan view schematically illustrating a related art intake system. [0011] [Mode for Carrying Out the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the drawings should be viewed in the orientation of symbols. Fig. 1 is a side view showing the appearance of a scooter-type vehicle including an intake system of the present invention; Fig. 2 is a plan view of the scooter- type vehicle shown in Fig. 1; Fig. 3 is a side view showing the appearance of the intake system; Fig. 4 is a plan view of essential portions of the intake system, with parts partially cutaway; Fig. 5 is an exploded perspective view of the intake system, wherein the air cleaner is shown in a cross-sectional plan view; and Fig. 6 is a plan view showing a positional relationship between a rear wheel and the intake system, wherein the air cleaner is shown in a cross-sectional plan view and also the flow of air is shown by arrows. In these figures, the front, rear, left, and right sides, which are denoted by symbols Fr, Rr, L, and R respectively, are based on the direction viewed by the driver. In Fig. 6, symbol C denotes the center line of the vehicular body. [0012] Referring to Figs. 1 and 2, there is shown a motorcycle 1 representative of a scooter-type vehicle to which the present invention is applied. A head pipe 2a is mounted to the front end of a frame 2. A front fork 4 for supporting a front wheel 3 is steerably supported by the head pipe 2a. A steering shaft 4a extends upward from the head pipe 2a, and a steering handlebar 5 is provided on the upper end of the steering shaft 4a. The frame 2 has a front half 2b extending at a low level. In addition, the front half 2b and later portions of the frame 2 are each composed of right and left members. A fuel tank 6 is arranged between the right and left members of the front half 2b. The frame 2 includes the front half 2b, a seat post 2c, and a rear portion 2d. The seat post 2c is sharply raised from the rear end of the front half 2b and extends rearward, obliquely upward, and the rear portion 2d extends rearward, slowly obliquely upward from the upper end of the seat post 2c. A seat 7 is arranged over both the seat post 2c and the rear portion 2d. Brackets 2f are provided on the lower surfaces of the right and left members of a curved portion 2e which is the boundary between the seat post 2c and the rear portion 2d, and the upper portion of the front half of a power unit 9 is pivotably supported by the brackets 2f via links 8. [0013] The power unit 9 includes at its front portion an engine 10 tilting forward, upward. A transmission case 11 serving as a crank case extends rearward from the rear end of the engine 10, and supports at its rear portion a rear wheel 12 as a drive wheel. Bosses lla, which project upward from the transmission case 11 at positions directly after the engine 10, are pivotably supported by the links 8, so that the unit swing type power unit 9 is swingably supported by the frame 2. Bosses lib are provided on the rear portion of the transmission case 11 of the power unit 9 in such a manner as to project upward therefrom, and rear cushion units 13 are interposed between the rear half of the rear portion 2d of the frame 2 and the bosses lib. An exhaust pipe 14 projecting downward from the engine 10 extends rearward on the right side of the motorcycle. The rear end of the exhaust pipe 14 is connected to the upstream side of a muffler 15 which extends rearward from the power unit 9. The exhaust system including the muffler 15 is supported by the power unit 9 including the engine via a muffler stay. [0014] The outer surface of the frame 2 is covered with a front cover 16, a floor 17, a seat post cover 18, and a rear cover 19 arranged in this order from the front of the body. The appearance of the body is constituted by these covers. In the figure, reference numeral 20 denotes an oil tank arranged in the rear of the rear portion 2d of the frame 2; 21 is a rear carrier; 22 is the rear half of a rear fender; 23 is a front fender; 24 is a battery arranged in the front cover 16; 25 is a headlamp; and 26 is one of right and left rear view mirror. [0015] An intake system 30 of the present invention will be described below. As shown by the appearance view of Fig. 1, the intake system 30 is mounted on and supported by the transmission case 11 of the power unit 9 in such a manner as to be swingable therewith. Figs. 3 to 6 show the details of the intake system 30. The intake system 30 is composed of an intake chamber 31 and an air cleaner 41. Fig. 5 shows the intake system 30 in a state in which the intake chamber 31 and the air cleaner 41 are disassembled from each other. In this figure, right and left cases of the air cleaner 41, which are disassembled from each other, are shown in a cross-sectional plan view. Fig. 4 is a cross-sectional plan view showing essential portions of the intake system 30 in a state in which the intake chamber 31 and the air cleaner 41 are assembled with each other. Fig. 6 is a plan view showing a positional relationship between the intake system 30 in the state in which the intake chamber 31 and the air cleaner 41 are assembled with each other and the rear wheel 12 and the vehicular body, with parts shown in a cross-sectional plan view. [0016] The intake chamber 31 is elongated longer in the width direction of the vehicular body. As shown in Figs. 5 and 6, the intake chamber 31 includes an intermediate portion 32 having a large capacity, and a pipe-like suction portion 33 which extends rightward from the intermediate portion 32. The suction portion 33 extends rightward, forward from the intermediate portion 32 in a state being curved in an approximately L-shape in a plan view and it has, at its right end, an intake port 34. A resonator 35 for reducing noise caused by air intake is provided on the suction portion 33. A pipe-like outlet 36, slightly projecting leftward, is integrally formed on the left side of the intermediate portion 32. [0017] A front half 37 of the rear fender is integrally formed on the intermediate portion 32 of the above intake chamber 31 in such a manner as to extend downward, forward therefrom. As shown in Fig. 3, the front portion of the intake chamber 31, for example, the lower end portion of an inverse triangle shaped stay 38 suspended downward from the pipe-like suction portion 33 is fastened by means of a bolt on a boss lie provided on the engine constituting part of the power unit 9 at a position opposed to the transmission case 11, to be thus mounted on and supported by the power unit 9. In this way, the intake chamber 31 is arranged on the transmission case 11 in such a manner as to cross the transmission case 11. Fig. 6 shows the state in which the intake chamber 31 is mounted on the power unit 9. In this state, the intermediate portion 32 is positioned over the front half of the rear wheel 12, and the upper surface of the front half of the rear wheel 12 is covered with the rear fender front half 37 additionally provided on the intermediate portion 32. [0018] The suction portion 33 extending rightward from the intermediate portion 32 extends rightward apart from a center line C of the vehicle, and as shown in Fig. 2, the intake port 34, i.e., the leading end of the suction portion 33 is opened in the right surface of the cover constituting the appearance of the vehicular body at a distance from the right surface of the rear wheel 12. That is to say, the intake port 34 of the intake chamber 31 is arranged opposite to the air cleaner 41 (which will be described later) with respect to the center line C of the vehicular body. The air cleaner 41 is elongated slightly longer in the longitudinal direction, and it is divided right and left in the width direction of the vehicular body into cases 42 and 43. [0019] The outer case 42 on the left side, which constitutes a cover, is short in dimension in the width direction of the vehicular body. The inner case 43 on the right side, which constitutes a main body, is longer than the outer case 42 on the left side in dimension in the width direction of the vehicular body. The inner case 43 has an opening edge portion 43a opened outward (on the left side) in the width direction of the vehicular body, and the outer case 42 has a butting edge portion 42 which has a groove 42a to be engaged with the opening edge portion 43a of the inner case 43. A cylindrical portion 44 projects inward from a central portion of the outer case 42, and a projection 45 to be fitted in the cylindrical portion 44 is provided on the inner case 43 at a position corresponding to that of the cylindrical portion 44. The outer case 42 is assembled with the inner case 43 as shown in Fig. 4 and is then connected thereto with a small screw 46. For exchange of an element 47 to be described later, the outer case 42 is disassembled from the inner case 43 by removal of the small screw 46. [0020] An element 47, typically an air filter, is removably fixed between the right and left cases 43 and 42 by holding the peripheral portion of the element 47 with the cases 43 and 42 and also holding appropriate positions of the element 47 with a plurality of ribs 43b and a plurality of ribs 42b respectively provided on the cases 43 and 42. The inside of the air cleaner 41 thus assembled is partitioned into a dirty side 48 (outer cover side) outside the element 47 and a clean side 49 (inner cover side) inside the element 47. An inlet pipe 50 formed of an arcuate pipe or the like is inserted in the front half of the inner case 43 in a state in which a connecting port 50a at the front end of the inlet pipe 50 is exposed from the outer surface of the inner front half of the inner case 43. The inner case 43 has a plurality of mounting stays 51 provided at the lower end portion thereof as shown in Fig. 3, and is mounted on and supported by a plurality of mounting bosses lid provided on the above transmission case 11 via the mounting stays 51. The front portion of the inner case 43 has a stay 43f projecting upward therefrom. The stay 43f is connected by means of a small screw to a boss 32a provided on the intermediate portion 32, at a position on the air cleaner 41 side, of the intake chamber 31 arranged on the inner side of the vehicular body (on the side of the center line of the vehicular body). [0021] Since the transmission case 11 is arranged on the left side of the rear wheel 12 with a distance put therebetween, the air cleaner 41 is also arranged on the left side of the rear wheel 12 with a distance put therebetween as shown in Fig. 6. A leading end 36a of the outlet 36 of the intake chamber 31 is fitted in and connected to the connecting port 50a, so that the intake chamber 31 is communicated to the inner case 43 of the air cleaner 41, that is, the dirty side 48 inside the element 47. The front end surface of the outer case 42 of the air cleaner 41 has a clean air outflow port 52 communicated to the clean side 47. An upstream end 53a of a connecting tube 53 having a downstream end connected to a carburetor 55 is connected to the outflow port 52 for supplying a clean air to the carburetor. Actually, the outflow port 52 is formed in a lid plate 54 provided in such a manner as to close the front end opening portion of the cases 42 and 43, and the upstream end 53a of the connecting tube 53 is fitted in and connected to the outflow port 52. [0022] The inner case 43 has a rear half 43c and a front half 43d. The rear half 43c has a larger width in the width direction of the vehicular body. The intermediate portion of the front half 43d is curved outward in a plan view to form a recess 43e for vertically containing part of the rear cushion 13 arranged close to the left side of the rear wheel 12. The inlet pipe 50 arranged in the front half of the inner case 42 is formed into an arcuate shape curved outward in accordance with the recess 43e. [0023] Fig. 6 also shows an air intake state of the intake system 30. Referring to Fig. 6, the intake chamber 31 is arranged in such a manner as to cross the front half of the rear wheel 12. To be more specific, the intake chamber 31 is offset largely from the center line C of the vehicular body on the side opposed to the air cleaner 41 side, and the intake port 34 through which outside air is introduced is opened in the right surface of the right body cover at a position separated largely from the right surface of the rear wheel 12. This prevents permeation of water drops or dust, splashed up or flied up by the rear wheel 12, into the intake chamber 31 through the intake port 34. [0024] As shown in Fig. 6, outside air less mixed with water drops or dust splashed up or flied up by the rear wheel 12 is sucked from the intake port 34 as shown by an arrow "1", passing through the intermediate portion 32 as shown by an arrow "2", and flows in the dirty side 48 of the air cleaner 41 as shown by an arrow "3". The air is then filtered in the element 47 as shown by an arrow "4", and flows in the clean side 49. The air thus cleaned flows in the upstream side of the connecting tube 53 as shown by an arrow "5", being sucked in the carburetor 55 and mixed with a fuel, and is supplied into an intake port of the engine as shown by an arrow "6". [0025] Since the air cleaner 41 is configured such that the dirty side 48 is located on the inner side, that is, on the rear wheel 12 side and the clean side 49 is located on the outer side, that is, on the left outer side in the width direction of the vehicular body, it is possible to eliminate the necessity of adopting the related art configuration in which the connecting tube is unreasonably bent outward from the inner clean side to be connected to the front carburetor so that the air cleaner is swelled outward with the entire width thereof extended. According to the present invention, the clean side 49 can be connected to the front carburetor 55 on the same side, and accordingly it is possible to suppress the amount of the entire air cleaner 41 swelled outward in the width direction of the vehicular body. This is effective to arrange the air cleaner and the intake chamber near the central portion in the width direction of the vehicular body while suppressing the dimension of the air cleaner in the width direction of the vehicular body. As a result, it is possible to suppress the projecting amount of the air cleaner 41 in the direction of the vehicular body while arranging the rear cushion unit 13 between the air cleaner 41 and the rear wheel 12 with a sufficient gap kept between the rear cushion unit 13 and the air cleaner 41, and hence to make small the dimension of the air cleaner 41 as a whole in the direction of the vehicular body. [0026] Since the intake chamber 31 is arranged such that the intake port 34 is located opposite to the air cleaner 41 with respect to the center line C of the vehicular body, it is possible to eliminate the necessity of arranging the intake port 34 in front of the rear wheel 12 and hence to suppress the longitudinal dimension of the intake chamber 31. This is advantageous in terms of space layout because the intake chamber 31 does not largely occupy the limited space on the transmission case on which auxiliaries of the engine must be mounted. In this way, the intake system of the present invention can be miniaturized as a whole while allowing effective air intake at a high efficiency. [0027] Since the outlet 36 constituting the connecting portion of the intake chamber 31 is directly connected to the connecting port 50a of the inlet pipe of the air cleaner 41, it is possible to eliminate the necessity of adopting the related art configuration in which a connecting duct member must be additionally provided for connecting the intake chamber 31 to the air cleaner 41, and hence to reduce the number of assembling steps as well as the number of parts. In addition, since the intake chamber 31 is formed integrally with the rear fender 37 for the rear wheel 12, it is possible to reduce the number of assembling steps as well as the number of parts, and also to eliminate the necessity of provision of a rear fender supporting stay. [0028] [Effects of the Invention] The present invention having the above configuration exhibits the following effects: According to the invention described in claim 1, an air cleaner is arranged on a transmission case of a unit swing type power unit including an engine and the transmission case, and an intake chamber is connected to the air cleaner; and the air cleaner is offset to one side from a center line of the vehicular body, and an intake port of the intake chamber is arranged opposite to the air cleaner with respect to the center line of the vehicular body. Accordingly, the intake port of the intake chamber is arranged largely apart from a rear wheel, so that it is possible to suppress permeation of water droplets or dust splashed up or flied up by the rear wheel into the intake port, and hence to preventing permeation of water droplets or dust into the intake chamber. As a result, it is possible to prevent early blocking or contamination of the element resulting from water droplets or dust, and hence to improve the service life and durability of the element. Also since outside air is less mixed with water droplets or dust, it is possible to realize effective air intake at a high efficiency. [0029] Since the intake chamber is arranged such that the intake port is located opposite to the air cleaner with respect to the center line of the vehicular body, it is possible to eliminate the necessity of arranging the intake port largely apart in front of the rear wheel and hence to suppress the longitudinal dimension of the intake chamber. This is advantageous in terms of space layout as compared with the related art system because the intake chamber does not largely occupy a limited space on the transmission case on which auxiliaries of the engine must be mounted. In this way, the intake system of the present invention can be miniaturized as a whole while allowing effective air intake at a high efficiency. Since the intake chamber is directly connected to the air cleaner, it is possible to eliminate the necessity of adopting the related art configuration in which a connecting duct member must be additionally provided for connecting the intake chamber to the air cleaner, and hence to reduce the number of assembling steps as well as the number of parts. [0030] According to the invention described in claim 2, in addition to the configuration of the invention described in claim 1, the air cleaner includes right and left cases dividedly arranged right and left in the width direction of the vehicular body with an element put therebetween, wherein an inner space and an outer space, which are partitioned from each other by the element and right and left cases, are taken as a dirty side and a clean side, respectively. Accordingly, it is possible to eliminate the necessity of adopting the related art configuration in which the clean side is arranged on the inner side and the connecting tube is unreasonably bent outward from the inner clean side to be connected to the front carburetor so that the air cleaner is swelled outward with the entire width thereof extended. That is to say, according to the present invention, the outer clean side can be connected to the carburetor or the like constituting the front fuel supply apparatus on the same side. Thus, it is possible to suppress the amount of the entire air cleaner swelled outward in the width direction of the vehicular body. This is effective to arrange the air cleaner and the intake chamber near the central portion in the width direction of the vehicular body while suppressing the dimension of the air cleaner in the width direction of the vehicular body. [0031] According to the invention described in claim 3, in addition to the configuration of the invention described in claim 1, the intake chamber is supported by the transmission case integrated with the engine, and a fender for the rear wheel is formed integrally with the intake chamber. Accordingly, it is possible to reduce the number of assembling steps as well as the number of parts. Also since it is not required to provide any rear fender supporting stay, it is possible to further reduce the number of assembling steps. [Explanation of Symbols] 1: scooter-type vehicle, 9: power unit, 10: engine, 11: transmission case, 12: rear wheel, 30: intake system, 31: intake chamber, 34: intake port, 37: rear wheel fender, 41: air cleaner, 42, 43: divided cases of air cleaner, 48: dirty side, 49: clean side, C: center line of vehicular body WE CLAIM : 1. An intake system for a power unit swing type scooter type vehicle in which a rear wheel is supported on the rear portion of a power unit composed of an engine and a transmission case and said power unit is swingably supported by a vehicular body, characterized in that an air cleaner is arranged on said transmission case of said power unit, and an intake chamber is connected to said air cleaner; and said air cleaner is offset to one side from a center line of the vehicular body, and an intake port of said intake chamber is arranged opposite to said air cleaner with respect to the center line of the vehicular body. 2. An intake system for a scooter-type vehicle as claimed in claim 1, wherein said air cleaner compr [right and left cases dividedly arranged right and left in the width direction of the vehicular body with an element put therebetween, wherein an inner space and an outer space, which are partitioned from each other by said element and right and left cases, are taken as a dirty side and a clean side, respectively. 3. An intake system for a scooter-type vehicle as claimed in claim 1, wherein said intake chamber is supported by said transmission case integrated with said engine, and a fender for the rear wheel is formed integrally with said intake chamber. 4. An intake system for a scooter-type vehicle as claimed in claim 1, wherein said intake chamber is arranged across a front half of a rear wheel. 5. An intake system for a power unit swing type scooter-type vehicle substantially as herein described with reference to the accompanying drawings.

Documents:

3565-del-1998-abstract.pdf

3565-del-1998-claims.pdf

3565-del-1998-correspondence-others.pdf

3565-del-1998-correspondence-po.pdf

3565-del-1998-description (complete).pdf

3565-del-1998-drawings.pdf

3565-del-1998-form-1.pdf

3565-del-1998-form-13.pdf

3565-del-1998-form-19.pdf

3565-del-1998-form-2.pdf

3565-del-1998-form-3.pdf

3565-del-1998-form-4.pdf

3565-del-1998-form-6.pdf

3565-del-1998-gpa.pdf

3565-del-1998-petition-137.pdf

3565-del-1998-petition-138.pdf

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