WO2003035459A1

WO2003035459A1 - Fixing structure of fuel cock in motorcycle

Info

Publication number: WO2003035459A1
Application number: PCT/JP2001/009213
Authority: WO
Inventors: Dai Hiwatashi; Yasuhiro Takada
Original assignee: Honda Giken Kogyo Kabushiki Kaisha
Priority date: 2001-10-19
Filing date: 2001-10-19
Publication date: 2003-05-01
Also published as: KR20040052228A; BR0117157B1; JP3811481B2; CN1291885C; TW526152B; BR0117157A; JPWO2003035459A1; AR033183A1; KR100556038B1; CN1558850A

Abstract

A motorcycle comprising an engine disposed below a main frame extending upward from a head pipe and suspended from a body frame having the main frame, and an air cleaner and a carburetor disposed above the engine, wherein a fuel cock operating with the negative intake pressure of the engine is provided on a fuel supply line coupling the carburetor and a fuel tank disposed below a passenger seat supported at the rear part of the body fame. The fuel cock (90) provided on the fuel supply line (88) extending downward from the fuel tank and coupled with the carburetor (38) is fixed to an intake pipe (39) connecting the carburetor (38) with the engine (E). A negative pressure take-out pipe between an intake system and the fuel cock is thereby shortened and the number of parts can be decreased by eliminating the need for a part dedicated to venting of air from the fuel supply line.

Description

Description Fuel cock mounting structure for motorcycles Field of the Invention

The present invention provides a vehicle body frame provided with a main frame extending downward from a head pipe, wherein an engine disposed below the main frame is suspended, and an air cleaner and a carburetor are disposed above the engine. In the middle of a fuel supply pipe connecting the fuel tank and the carburetor disposed below the riding seat supported at the rear of the vehicle, a negative pressure-operated fuel cock operated by negative pressure of the intake air of the engine is provided. In particular, it relates to improvement of fuel cock mounting structure. Conventionally, such a motorcycle is known, for example, from Japanese Patent Publication No. 7-106711, and includes a fuel tank disposed below a rider's seat, A negative pressure-operated fuel cock provided between a carburetor and a carburetor disposed below and forward is disposed below the fuel tank and attached to the fuel tank.

However, in the above conventional apparatus, the fuel cock is arranged at a position separated from the carburetor, and accordingly, the negative pressure extraction pipe for extracting the negative pressure from the intake device including the carburetor and guiding the negative pressure to the fuel cock becomes longer. Not only that, the length of the portion of the fuel supply line connecting the carburetor and the fuel cock increases, and when air is mixed into the fuel supply line due to the stoppage of fuel supply from the fuel tank, It takes time to exchange air and fuel in the fuel supply line at the time of refueling, and a relief valve for air release is required.

The present invention has been made in view of the above circumstances, and has been made to reduce the length of a negative pressure extraction pipe between an intake device and a fuel cock, and to eliminate the need for a dedicated part for bleeding air from a fuel supply pipe. It is an object of the present invention to provide a fuel cock mounting structure for a motorcycle that can reduce the number of points.

Disclosure of the invention

In order to achieve the above object, the present invention extends backward from a head pipe. An engine disposed below the main frame is suspended from a body frame including a main frame, an air cleaner and a carburetor are disposed above the engine, and disposed below a riding seat supported by a rear portion of the body frame. A motorcycle provided with a negative-pressure-operated fuel cock operated by negative pressure of the intake air of the engine in the middle of the fuel tank to be connected and the fuel supply line connecting the carburetor, A first feature is that the fuel cock, which is provided in the middle of a fuel supply pipe extending and connected to the carburetor, is attached to an intake pipe connecting the carburetor and an engine.

According to the configuration of the first feature, the fuel cock can be brought close to the carburetor, the length of the negative pressure take-out line for guiding the negative pressure from the intake device to the fuel cock can be shortened, and the fuel The length of the supply line connecting the carburetor and the fuel cock can be shortened. In addition, the fuel supply system connecting the fuel tank and the carburetor is provided with 15 pipes at the front, so even if air is mixed into the pipe section due to the stoppage of fuel supply from the fuel tank, it will not Even if the work of bleeding air from the pipe section is omitted, the entire fuel supply pipe can be quickly filled with fuel, and parts such as a relief valve for bleeding air are not required, and the number of parts can be reduced. Finally, fuel can be quickly supplied to the carburetor.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the fuel cock is attached to an attachment step provided integrally with the intake pipe. However, the fuel cock is attached to the intake pipe of the intake device, so that the degree of freedom in arranging the fuel cock can be increased as compared with the case where the fuel cock is attached to the fuel tank.

Further, according to the third aspect of the present invention, in addition to the configuration of the first aspect, the fuel cock is disposed on a side opposite to the carburetor across the main frame. In addition, the fuel supply pipe and the negative pressure take-out pipe can be easily piped.

BRIEF DESCRIPTION OF THE FIGURES

1 to 6 show an embodiment of the present invention. FIG. 1 is a side view of a motorcycle, FIG. 2 is a left side view of the motorcycle near an engine, and FIG. 3 is a motorcycle near an engine. Right side view of the car, Fig. 4 is a view taken in the direction of arrow 4 in Fig. 2 without the main frame, Fig. 5 is an enlarged sectional view taken along line 5-5 in Fig. 3, and Fig. 6 is an enlarged view taken along line 6-6 in Fig. It is sectional drawing.

BEST MODE FOR CARRYING OUT THE INVENTION

First, in FIG. 1, a body frame F of the motorcycle includes a head pipe 12 for supporting the front fork 11 so as to be steerable, a main frame 13 extending rearward and downward from the head pipe 12, and a main frame 1. 3 and a pair of left and right lyaframes 14 connected to the rear and extending upward. The front wheel WF is rotatably supported at the lower end of the front fork 11, and the upper end of the front fork 11 is provided. The steering handle 15 is connected to.

Referring to FIGS. 2 and 3 together, hanger plates 16 are fixed to both sides of the intermediate portion of the main frame 13, and pivot plates 17 are attached to both sides of the rear of the main frame 13. Is fixed.

An engine E having a cylinder axis C 1 inclined forward is disposed below the main frame 13. The engine E is supported by the hanger plate 16 and the pivot plate 17 so that the vehicle body is Suspended on frame F. On both sides of the engine E, footsteps 18 for occupants to put their feet on are provided.

The pivot plate 17 is provided with a cylindrical support shaft 20, and front ends of a pair of left and right lyaforks 21... Are supported on both ends of the support shaft 20 so as to be able to swing up and down. Rear fork 2 1 ... The rear wheel WR is supported between the rear ends.

The upper part of the rear wheel WR is covered by a lender fender 24 attached to the lya frame 14. A fuel tank 25 supported by the lya frame 14 is arranged above the lender fender 24. Is done. A tandem seat 26, which is a riding seat, is arranged so as to cover the fuel tank 25, and a lya cushion unit 27 is provided between the lya frame 14 and the lya forks 2 1 ... Each is provided.

The body frame F is covered with a body cover 30 made of synthetic resin. The body cover — 30 is a pair of left and right main frame side covers 31 that cover both sides of the main frame 13, and occupant legs. A pair of left and right leder shields 3 2… that are fastened to the front of both main frame side covers 3 1… The front top cover 33 connected to the two red shields 3 2 ... and the head pipe 12 are covered from the rear side while covering the eve 12 from the front side, and the main frame 13 is covered from the upper side. The upper cover 3 4 connected to the front top cover 3 3, the under force par 3 5 connected to the lower part of the two main frame side covers 3 1… and the rear of the body frame F together with most of the fuel tank 25 And a pair of right and left lya side covers 36 to cover each other.

Referring also to FIG. 4, an intake device 40 including an air cleaner 37, a carburetor 38 and an intake pipe 39 is arranged above the engine E.

At the top of the air cleaner 37, a pair of mounting plates 37a, 37a sandwiching the main frame 13 from both sides are provided on the body, and both mounting plates 37a, 37a are provided. It is fastened to both sides of the main frame 13 by ports 41, 41. That is, the vacuum cleaner 37 is fixed to the main frame 13.

The upstream end of the carburetor 38 located above the cylinder head 42 in the engine E is directly connected to the air cleaner 37, and the intake pipe whose upstream end is connected to the downstream end of the carburetor 38 39 is formed in a substantially C-shape, and the downstream end of the intake pipe 39 is connected to the intake port 43 arranged at the upper part of the cylinder head 42 so that the downstream end of the cylinder 39 is connected to the cylinder head 42. Connected to upper side wall.

An upstream end of an exhaust pipe 45 is connected to a lower side wall of the cylinder head 42 so as to be continuous with an exhaust port 44 arranged below the cylinder head 42. The exhaust pipe 45 extends rearward from the cylinder head 42 and is connected to an exhaust muffler 46 (see FIG. 1) arranged on the right side of the rear wheel WR.

The exhaust port 44 of the cylinder head 42 of the engine E is supplied with secondary air for exhaust, and the secondary air control for controlling the supply of the secondary air to the exhaust port 44 A valve 48 is arranged between the carburetor 38 and the carburetor 38 attached to the upper part of the crankcase 49 of the engine E, and between the engine E and the main frame 13.

In FIG. 5, the secondary air control valve 48 includes a diaphragm actuator 52, an on-off valve 53 driven to close by the diaphragm actuator 52, and an exhaust port 4 of the engine E. It is composed of a reed valve 54 that allows only air flow to the 4 side. The diaphragm actuator 52 includes a casing 55, a diaphragm 56 whose peripheral edge is sandwiched by the casing 55, and a metal rod 57 having one end connected to the center of the diaphragm 56. And

The casing 55 includes a body 58, and a cover 59 that is fastened to the pod 58 by hermetically sandwiching the periphery of the diaphragm 56 therebetween. A negative pressure chamber 60 facing one side of the diaphragm 56 is formed between the diaphragm 56 and the atmospheric pressure chamber 61 between the body 58 and the diaphragm 56. At the center of the cover 59, a connecting pipe portion 63 having a throttle hole 62 at its tip is continuously provided, and a negative pressure outlet pipe communicating with the negative pressure chamber 60 through the throttle hole 62 is provided. 6 is connected to a connection pipe section 63, and the negative pressure extraction pipe line 64 is connected to an intake pipe 39 of the suction device 40 as shown in FIG. As a result, the negative pressure in the intake pipe 39 acts on the negative pressure chamber 60.

The rod 57 is supported by the body 58 so as to be movable in the axial direction, and one end of the rod 57 is directly connected to the center of the diaphragm 56 on the atmospheric pressure chamber 61 side. In Kuchiyue 52, when the negative pressure in the intake pipe 39 increases, the diaphragm 56 flexes in the direction of decreasing the volume of the negative pressure chamber 60, and the rod 57 moves upward in FIG. Will work.

The on-off valve 53 includes a valve housing 67, a valve element 68 fixed to the other end of the rod 57, and a return spring 69 provided between the valve housing 67 and the valve element 68. .

The valve housing 67 includes the body 58 and a suction cover 70 that is hermetically fastened to the body 58. The body 58 has an air flow passage 71 and an air flow passage. A communication hole 72 for communicating the passage 71 with the atmospheric pressure chamber 61; a valve hole 73 communicating with the rod 57 through the upstream end of the air passage 71; and the air passage 7 A valve seat 74 having the valve hole 73 opened in the center on the opposite side to 1 and a support cylinder 75 partially inserted coaxially into the valve hole 73 are provided. A rod 57 coaxially penetrating 73 is fitted in the support cylinder 75 so as to be slidable in the axial direction. A valve chamber 76 is formed between the body 58 and the suction cover 70. The suction cover 70 has a connection pipe portion 77 connected to the valve chamber 76 in the body, and the downstream end of the pipe line 78 is connected to the connection pipe 77. The upstream end of the conduit 78 is connected to a secondary air cleaner 79, and an air introduction conduit 80 connected to the upstream end of the secondary air cleaner 79 is connected to the main frame 13 near the head pipe 12. It is extended forward along. Moreover, the secondary air cleaner 79 is disposed on the opposite side of the carburetor 38 with respect to the center line C2 passing through the center of the main frame 13 in the width direction.

The valve seat 74 is formed in the body 58 so as to face the valve chamber 76, and the valve body 68 accommodated in the valve chamber 76 so as to be able to be seated on the valve seat 74 is provided with a rod 57 other than the rod 57. It is fixed at the end.

The return spring 69 has a coil shape surrounding the support cylindrical portion 75, and the direction in which the valve element 68 is separated from the valve seat 74, that is, the diaphragm 5 of the diaphragm actuator 52. The spring 6 is provided between the body 58 and the valve element 68 by exerting a spring force in a direction of bending the element 6 toward the atmospheric pressure chamber 61.

The reed valve 54 is supported by a disc-shaped valve support plate 82 having a valve hole 81 at the center so as to be able to open and close the valve hole 81. The plate 82 is hermetically sandwiched between the body 58 and the third cover 83 fastened to the pod 58 so that the valve hole 81 communicates with the downstream end of the air flow passage 71. You. A valve chamber 84 for accommodating the reed valve 54 is formed between the third cover 83 and the valve holding plate 82, and is connected to the third cover 83 so as to communicate with the valve chamber 84. The upstream end of the secondary air supply line 86 is connected to the connection tube 85 provided integrally. The downstream end of the secondary air supply pipe 86 is connected to a lower portion of the cylinder head 42 so as to communicate with the exhaust port 44 of the cylinder head 42 of the engine E.

In addition, most of the secondary air supply line 86 is arranged on the opposite side of the carburetor 38 with respect to the center line C2 passing through the center of the main frame 13 in the width direction.

Such a secondary air control valve 48 is fixed to the main frame 13 of the body frame F. That is, a stay 87 is fastened to the side surface of the main frame 13, and a support flange 58 a provided integrally with the body 58 so as to contact the stay 87 from below is provided on the stay 87. Will be concluded. A fuel tank 25 disposed below the tandem seat 26 and a carburetor 38 disposed before and below the fuel tank 25 include a fuel supply line 8 extending forward and downward from the fuel tank 25. In the middle of the fuel supply line 88, a negative pressure-operated fuel cock 90 that operates with the intake negative pressure of the engine E is provided.

In FIG. 6, a fuel cock 90 includes a casing 91, a diaphragm 92 having a peripheral portion sandwiched by the casing 91, a valve body 93 fixed to a central portion of the diaphragm 92, and a casing. 9 and a return spring 94 provided between the diaphragm 92.

The casing 91 includes a body 95 and a cover 96 which is airtightly sandwiched between the peripheral portions of the diaphragm 92 and is connected to the pod 95 by caulking. A negative pressure chamber 97 facing one surface of the diaphragm 92 is formed between 6 and the diaphragm 92. In addition, a spring support plate 98 is in contact with the inner surface of the force par 95 in the negative pressure chamber 97, and the return spring 94 is provided with a diaphragm 92 on the side of increasing the volume of the negative pressure chamber 97. It is contracted between the diaphragm 92 and the spring receiving plate 98 so as to exert a spring force in a bending direction.

The cover 96 is provided with a connecting pipe portion 99 communicating with the negative pressure chamber 97 on the body, and a negative pressure is applied between the connecting pipe portion 99 and the intake pipe 39 of the intake device 40. Connected at the take-out line 100. That is, the negative pressure in the intake pipe 39 is introduced into the negative pressure chamber 97.

A valve chamber 101 is formed between the diaphragm 92 and the body 95, and a valve seat in which the valve body 93 fixed to the center of the diaphragm 92 is seated in the body 95. 102 and a valve hole 103 having a downstream end opened at the center of the valve seat 102. Moreover, of the fuel supply line 88, a line portion 88a connecting the fuel tank 25 and the fuel cock 90 is connected to the body 95 so as to communicate with the valve hole 103, and the fuel line Of the 88, a pipe portion 8b connecting between the carburetor 38 and the fuel cock 90 is connected to the body 95 so as to communicate with the valve chamber 101.

By the way, the intake pipe 39 is provided with a mounting stay 39 a that protrudes toward the fuel cock 90 side, and the support plate 104 fastened to the mounting stay 39 a has the above-mentioned structure. A flange 95 a provided integrally with the body 95 of the fuel cock 90 is fastened. That is, the fuel cock 90 is attached to the intake pipe 39. Like this When installed in the pipe 39, the fuel cock 90 is disposed below the main frame 13 and beside the secondary air control valve 48, and is opposite to the carburetor 38 with the main frame 13 interposed therebetween. Placed on the side.

A bleed air supply line 105 for guiding bleed air to the carburetor 38 is provided between the air cleaner 37 and the carburetor 38.In the middle of the bleed air supply line 105, A lead air air cleaner 106 is provided so as to be disposed above the secondary air cleaner 79.

Next, the operation of this embodiment will be described. The cylinder axis C 1 is tilted forward to control the supply of the secondary air for exhaust to the exhaust port 44 of the engine E disposed below the main frame 13. A secondary air control valve 48 is provided between the carburetor 38 of the intake device 40 located above the engine E and the cello 50 attached to the upper part of the engine E, and the engine E and the main It is located between frames 13 and 13. Therefore, the secondary air control valve 48 is effectively activated in the space created between the engine E and the main frame 13 with the cylinder axis C1 tilted forward, and between the carburetor 38 and Serumo 50. Can be arranged. In addition, since the secondary air control valve 48 is located near the engine E, the secondary air supply line 8 6 connecting the secondary air control valve 48 and the exhaust port 44 of the engine E Can be shortened.

A secondary air cleaner 79 connected upstream from the secondary air control valve 48 is disposed on the opposite side of the carburetor 38 with respect to a center line C 2 passing through the center of the main frame 13 in the width direction. The carburetor 38 and the secondary air cleaner 79 are arranged at positions offset in the width direction of the body frame F, and the carburetor 38 and the secondary air cleaner 79 are disposed in a narrow space between the engine E and the main frame 13. The secondary air cleaner 79 can be effectively arranged.

Further, most of the secondary air supply line 86 is disposed on the opposite side of the carburetor 38 with respect to the center line C2 passing through the center of the main frame 13 in the width direction. And the secondary air supply pipe 86 can be placed closer to the main frame 13 to be compactly arranged.

Further, a negative pressure-operated fuel is provided in the middle of a fuel supply line 88 to the carburetor 48. A cock 90 is disposed below the main frame 13 and beside the secondary air control valve 48, and is connected between the carburetor 38 and the starter motor 50. Since the fuel cock 90 is disposed on the side, the fuel cock 90 can be brought close to the carburetor 38, and the negative pressure extraction pipe 10 that guides the negative pressure from the intake device 40 to the fuel cock 90 0 can be shortened.

Also, since the fuel cock 90 is disposed on the opposite side of the carburetor 38 with the main frame 13 therebetween, the piping of the fuel supply line 88 and the negative pressure extraction line 100 is facilitated. This comes out.

In addition, since a fuel cock 90 is provided in the middle of the fuel supply line 88 extending from the fuel tank 25 to the front and connected to the gas ridging device 38, the fuel supply from the fuel tank 25 is stopped. Therefore, even if air enters the pipe section 8 8b connecting the gas-riding device 38 and the fuel cock 90 in the fuel supply pipe 88, the pipe section 8 8 Even if the operation of bleeding air from b is omitted, fuel can be quickly filled in the pipeline section 8 8 b, and the number of parts can be reduced by eliminating the need for parts such as relief valves for air bleeding, and vaporizing. The fuel can be quickly supplied to the container 38.

Further, since the fuel cock 90 is attached to the intake pipe 39 of the intake device 40, the arrangement of the fuel cock 90 is different from that in which the fuel cock 90 is attached to the fuel tank 25. The above degree of freedom can be increased.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible.

Claims

The scope of the claims

1. An engine (E) disposed below the main frame (13) is suspended from a body frame (F) having a main frame (13) extending downward from the bed pipe (12), and an air cleaner ( 37) and a carburetor (38) are arranged above the engine (E), and a fuel tank (25) and a fuel tank (25) arranged below a rider seat (26) supported at the rear of the body frame (F). In a motorcycle, a negative pressure-operated fuel cock (90) that operates by a negative intake air pressure of the engine (E) is provided in the middle of a fuel supply pipe (88) connecting the carburetor (38). The fuel cock (90), which extends downward from the fuel tank (25) and is interposed in the middle of a fuel supply pipe (88) connected to the carburetor (38), is connected to the carburetor (38). And the intake pipe (39) that connects between the engine and the engine (E). Features A fuel cock mounting structure for motorcycles.

2. The fuel cock mounting structure for a motorcycle according to claim 1, wherein the fuel cock (90) is mounted on a mounting stay (39a) provided integrally with the intake pipe (39).

3. The fuel cock mounting structure for a motorcycle according to claim 1, wherein the fuel cock (90) is arranged on the opposite side of the carburetor (38) with the main frame (13) interposed therebetween. .