JP3463384B2 - Vehicle engine intake system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine intake system for a vehicle, which has a structure for mounting a carburetor air vent pipe of a motorcycle using traveling wind supercharging. 2. Description of the Related Art A carburetor of a vehicle such as a motorcycle is configured to atomize fuel during intake to form an air-fuel mixture and supply the air-fuel mixture to an engine. For stable supply of fuel, the carburetor is provided with a fuel storage chamber provided with a float (referred to as a float chamber), and the float and the float valve keep the fuel oil level constant. The outside air is introduced into the float chamber by an air vent pipe to maintain the pressure of the float chamber at atmospheric pressure. Usually, the outside air introduced through the air vent pipe is maintained at a constant pressure (at a constant atmospheric pressure). Therefore, the open end of the air vent pipe for introducing outside air is provided at a position which is not affected by the traveling wind. [0003] On the other hand, in a vehicle engine, an air inlet for an air cleaner is opened in the front of the vehicle so that the pressure of the traveling wind applied to the front is positively introduced into the intake of the carburetor to increase the charging efficiency. Some use the traveling wind supercharging (see Japanese Utility Model Laid-Open No. 63-121190).
In the case of this type of engine, there is a proposal to arrange the air vent pipe in front of the vehicle, apply the same pressure to the float chamber of the carburetor as in the cleaner box, and maintain a setting balance of the carburetor (for example, Japanese Utility Model Application Laid-Open No. HEI 3-103). No. 87856, Japanese Utility Model Laid-Open No. 3-95059).
In the proposals of these publications, the air vent pipe faces the air intake to the air cleaner. [0004] However, when the traveling wind supercharging is used, the setting of the carburetor changes if the direction of the tip of the air vent pipe is not constant with respect to the traveling wind flow. Therefore, it is necessary to fix the air vent pipe so that the direction of the tip is parallel to the traveling wind. [0005] On the other hand, Japanese Utility Model Application Laid-Open No. 3-87856 has been disclosed.
In Japanese Unexamined Utility Model Publication No. Hei 3-95059, the air vent pipe is fixed only at the position where the air vent pipe is retracted from the air intake port to the air cleaner. There is a high possibility that the orientation will vary and tilt will occur. Also,
If the tip of the air vent pipe is made to have high rigidity, or if the tip of the air vent pipe is simply fixed by using a separate bracket, the formation of the air vent pipe mounting portion becomes complicated and the assembling property is poor. There is a problem. SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and has a relatively simple shape for mounting an air vent pipe and can be easily assembled. It is an object of the present invention to provide an engine intake device for a vehicle that can be securely fixed without variation. Means for Solving the Problems The invention according to claim 1 is:
An engine intake of a vehicle in which intake air is introduced into a carburetor through an intake passage formed of an air intake pipe and an air cleaner box from an intake intake opening in front of a fairing of the vehicle, and outside air is introduced into an air vent pipe into a float chamber of the carburetor. A soft resin molded product made of a rubber composition, wherein an opening edge portion protruding rearward from an intake opening of the fairing in a cylindrical shape and a tip end of an air intake pipe forming the intake passage are provided. In addition to the joint pipe formed by the above, a raised portion protruding from the axial center part to the rear end part of the joint pipe toward the central axis side is provided to form a mounting part for attaching the tip of the air vent pipe. It is characterized by doing. According to the first aspect of the present invention, the tip of the air vent pipe is attached and fixed to the joint pipe connecting the edge of the fairing opening and the tip of the intake passage. If the attachment part is made integral with the joint pipe, molding can be facilitated. Further, if the joint pipe is made of a soft resin molded product such as rubber, the fairing opening edge and the tip of the intake passage can be connected with good airtightness. Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 4 are explanatory diagrams of an engine intake device for a motorcycle according to an embodiment of the present invention. FIGS. 1A and 1B are schematic front and side views of the motorcycle.
FIG. 2 is an explanatory view of the overall configuration of the intake device, FIG. 3 is an explanatory view of assembling a main part of the intake device, FIG. 4 (a), and FIG.
FIG. 4B is a sectional view taken along the line A, and FIG.
It is sectional drawing along a line. The present embodiment is directed to a fairing 1 of a motorcycle.
0 Intake air is introduced into the carburetor 16 through the air intake pipe (corresponding to a part of the intake passage) 14 from the intake intake ports 10b and 10b opened to the front, and the air vent pipe 1 is introduced into the float chamber 16a of the carburetor 16.
8, the opening edge 12a of the fairing 10 and the tip 14a of the air intake pipe 14 are connected to the joint pipe 2
0 and connected to the joint pipe 20 at the tip end of the air vent pipe 18 (corresponding to the mounting portion) 2
2 is provided. As shown in FIG. 1, the motorcycle of the embodiment has an elliptical shape or an oval shape having a vertically long outer shape when viewed from the front. A fairing (also referred to as a cowling) 10 is provided around the engine 8. On the front surface of the fairing 10, a shield surface 10a of the headlamp is formed at a position protruding most forward.
Are provided, and at the same time, a pair of left and right intake openings 10b and 10b are opened immediately beside the shield surface 10a. In addition, the opening position of the air intake can be set as appropriate, and can be provided, for example, at the lower side of the shield surface 10a denoted by reference numeral 10b2. The fairing 10
The opening portions (openings) 12 of the intake ports 10b, 10b are formed such that an opening edge 12a surrounding the intake ports 10b, 10b projects cylindrically rearward. The fairing opening edge 12a and the end 14a of the air intake pipe 14 are connected by a joint pipe 20. The joint pipe 20 is provided with a mounting pipe 22 at the end of the air vent pipe 18. The outer peripheral surface shape of the rear end of the opening edge portion 12a has a rectangular shape, and is substantially the same as the inner peripheral surface shape of the distal end of the joint pipe 20. Along the axial direction of the joint pipe 20 from the central portion 20a to the rear end portion 20b, as shown in the cross-sectional shape of FIG. 3 and FIG. First, a bulged portion 24 having a rectangular cross section in which the mounting pipe 22 is fitted is formed so as to protrude toward the central axis of the joint pipe 20. The mounting pipe 22
As shown in FIG. 4, the whole is a tubular body, and a tapered portion (or funnel-shaped portion) 22a having a forwardly expanding end is formed at the front end.
Are formed along a straight line except for the tapered portion 22a. The raised portion 24 of the air vent pipe 18 has a through hole 26 in which the mounting pipe 22 is fitted in parallel with the axial direction of the joint pipe 20.
Are drilled. The inner peripheral surface shape of the through hole 26 is formed in a shape adapted to the outer peripheral surface shape of the mounting pipe 22, and along the axial direction of the joint pipe 20, the length of the raised portion 24 is larger than the length of the raised portion 24. Since the length of the mounting pipe 22 is long, the rear end 22 b of the mounting pipe 22 protrudes from the rear end face of the joint pipe 20. The rear end 22b
The end of the vent pipe 18 is externally fitted to and fixed to the fitting pipe 2 so that
The two become one. The tip 1 of the air intake pipe 14
Reference numeral 4a denotes a pipe having a certain length in the flow direction of the intake air having the same outer peripheral surface shape as the inner peripheral surface shape of the joint pipe 20. The air intake pipe 14 is formed in a duct having a rectangular cross section after the certain length, and is connected to the air cleaner box 30 via the chamber 28 on the way. Reaches the carburetor 16 and forms one embodiment of the intake passage of the present invention. In the middle of the air vent pipe 18, an air cleaner 32 is provided. The joint pipe 20 can be made of an elastic body made of a rubber composition.
The material is ethylene propylene rubber (EPDM). The air intake pipe 14 may be formed of a resin or metal molded product, and is preferably formed of polypropylene (PP). The mounting pipe 22 can be made of a resin molded product or metal, and can be made of STKM 11A.
The mounting pipe 22 has a tip 22a formed in a tapered shape so as not to be pulled backward. Further, the tapered tip shape regulates the direction of the pipe and also serves as positioning. In addition, the outer diameter of the mounting pipe 22 is formed to be slightly larger than the inner diameter of the through hole 26 so as not to come off. The joint pipe 20
In addition to forming the through hole 26 integrally, the mounting pipe 22 may be insert-molded (baked). Further, if the pipe 22 is bonded or insert-molded to the joint pipe 20, it is possible to fix the pipe 22 more securely. The inside diameter of the attachment pipe 22 on the joint pipe 20 side to be inserted is the air vent pipe 1
The diameter of the pipe 8 is made smaller to prevent the pipe from coming off.
Further, a step-out or the like of the air vent pipe 18 is formed on the outer periphery on the rear end side of the mounting pipe 22. Next, the operation of the embodiment will be described. The air taken in through the opening 10 a of the cowling 10 passes through the join pipe 20 and the air intake pipe 14, is introduced into the air cleaner 30, is mixed with gasoline by the carburetor 16, and the air-fuel mixture is supplied to the engine 8. Also,
The joint pipe 20 includes an air vent pipe 18.
A mounting pipe 22 for mounting is fixed, and one end of the air vent pipe 18 is connected to the mounting pipe 22. The other end (rear end) of the air vent pipe 18 is connected to the upper space of the float chamber 16a of the carburetor 16, and in the middle of the air vent pipe 18,
A filter 32 is provided, and the air in the opening 10b is introduced into the float chamber 16a through the air vent pipe 18. The joint pipe 20 has a relatively simple shape as shown in FIG. 4, and can be easily assembled because only the air vent pipe 18 is attached and the pipe 22 is inserted. In addition, since the tip of the air vent pipe 18 can be securely fixed without tilting without variation,
The traveling wind pressure can be reliably introduced into the carburetor 16 float chamber 16a, and the setting balance of the carburetor 16 can be maintained. Further, by joining the cowling 10 and the air intake pipe 14 with a joint pipe 20 made of rubber or the like, the airtightness is maintained and the assembling property is improved. Since the shape of the joint pipe 20 is not complicated, it is relatively easy to form the attachment portion for the air vent 18. Also, the joint pipe 20 can be integrally molded in the axial direction, and is easy to manufacture. The present invention is not limited to the above-described embodiment. For example, as shown in a modified example of FIG.
The joint pipe 34 can be formed so as to be covered by the distal end 14a of the air intake pipe 14 including a. In this case, the vent pipe 18 once goes out of the intake pipe 14 and connects to the float chamber of the carburetor 16. As described above, according to the present invention, the mounting portion of the air vent pipe has a relatively simple shape and can be easily assembled. In addition, since the tip of the air vent pipe can be securely fixed without variation, the setting balance of the carburetor can be maintained.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A and 1B are a schematic front view and a side view of a motorcycle according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of the overall configuration of the intake device of FIG. 1; FIG. 3 is an explanatory view for assembling main parts of the intake device of FIG. 1; FIG. 4A is a cross-sectional view taken along line AA of FIG. 2;
(B) is sectional drawing along the BB line | wire of (a). FIGS. 5 (a) and 5 (b) are a main part sectional view and a main part perspective view for explaining a modification of the embodiment. DESCRIPTION OF SYMBOLS 10 Fairing 10b, 10b Intake port 12 Opening 12a Opening edge 14 Air intake pipe (corresponding to part of intake passage) 14a Tip end of air intake pipe 16 Carburetor 16a Float chamber 18 Air vent pipe 20 , 34 Joint pipe 22 Mounting pipe (mounting part) 24, 34a Rising part 26 Through hole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-200828 (JP, A) JP-A-3-87856 (JP, U) JP-A-3-95059 (JP, U) JP-A-3-95056 1250 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02M 5/08 F02M 17/34 F02M 35/10 F02M 35/16

Claims (1)

(57) [Claims] [Claim 1] An air intake pipe and an air cleaner box are formed through an intake opening opened in front of a fairing of a vehicle.
In the engine intake system for a vehicle, in which intake air is introduced into a carburetor through an intake passage made of gas and air is introduced into a float chamber of the carburetor by an air vent pipe , a cylindrical shape is formed rearward from an intake intake of the fairing.
Air inlet forming the intake passage and an opening edge protruding into the air inlet
The tip of the take pipe is made of a soft resin
While connecting with a joint pipe formed of shaped products ,
From the axial center to the rear end of this joint pipe,
A protruding portion protruding toward the central shaft side to form a mounting portion for mounting a tip of the air vent pipe.