JP2847499B2 - Saddle-type vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a straddle-type vehicle such as a four-wheeled vehicle, and more particularly, to an arrangement structure of an intake duct connected to an engine of the vehicle.

[0002]

2. Description of the Related Art In general, a straddle-type vehicle has front wheels (steering wheels) mounted on the front left and right sides of a frame (body frame) via suspension devices (struts, etc.) and is provided at the center of the frame. The left and right rear wheels (drive wheels) are mounted on a swing arm swingably supported by a pivot shaft and suspended by a load-carrying cushion unit, and the steering shaft supported by the front of the frame is turned by a steering wheel. The front two wheels are steered by moving the vehicle, and the vehicle is driven by driving the rear wheels by an engine mounted in the center of the frame.

[0003] A fuel tank, a seat, a carrier and the like are mounted on the upper portion of the frame from the front. A driver straddles the seat, grasps the steering wheel, and places his feet on steps mounted on the left and right sides of the lower portion of the frame. Board. In addition, covers for covering the inside of the vehicle body and covering the front and rear wheels are also attached to the frame. A document that discloses this type of straddle-type vehicle is disclosed, for example, in Japanese Patent Application Laid-Open No. 1-223089.

The covers include a front fender that covers the front wheel portion, a tank cover that covers the fuel tank, a rear fender that covers the rear wheel portion, and side covers that cover left and right side portions of the frame. In these covers, adjacent covers are appropriately integrated or conversely subdivided in consideration of productivity and assemblability.

On the other hand, the frame of the straddle-type vehicle is usually formed of a welding assembly such as a pipe, and generally includes left and right main upper members, left and right main lower members, and left and right main upper members. A plurality of side members connecting the main lower members at predetermined positions in the front-rear direction, a plurality of cross members connecting the left and right main upper members and the left and right main lower members at a plurality of positions in the front-rear direction, and a left and right main upper The vehicle includes left and right seat rails extending rearward from the members, and left and right rear members extending obliquely from the middle of the rear side members toward the middle of the seat rails.

[0006] Fuel supply to an engine mounted in the central portion of the vehicle body (the central portion of the frame) mixes the outside air sucked through an intake duct and an air cleaner with fuel measured by a carburetor or a fuel injection valve. The air-fuel mixture is charged into the combustion chamber through an intake port and an intake valve.

[0007] On the other hand, saddle-ride type vehicles are frequently used for running on uneven terrain, so that the lower half of the vehicle body is often exposed to dust and muddy water during traveling as compared with automobiles and the like, and various measures have been taken for that purpose. It has been subjected. For example, in the engine intake system of a straddle-type vehicle, a relatively long intake duct (for example, a snorkel-type intake duct) extending from the air cleaner to the upper part of the vehicle body from the viewpoint of preventing dust and muddy water from being mixed into the intake air. And the open end (air intake) of the intake duct is arranged above the vehicle body (for example, the front upper part) where the air is clean. Documents showing conventional examples of such an intake device include, for example, Japanese Utility Model Publication No. 2-13739, Japanese Utility Model Publication No. 5-3429, and Japanese Patent Publication No. Hei 6-76073.
No. Gazette.

If the cross-sectional shape of the intake duct is long, the intake pulsation is likely to occur. Since the intake pulsation is a compression wave of air, the fuel supply amount in the carburetor is not sufficient. In some cases, it becomes difficult to maintain an appropriate air-fuel ratio. In order to prevent this intake pulsation, it is necessary to provide a chamber in the middle of the intake duct or to change the sectional shape of the intake duct. On the other hand, as a structure for mounting an intake duct in a conventional straddle-type vehicle, a structure is adopted in which an intake duct is disposed in a place hard to be seen from the outside of a vehicle body, or a cover covers the intake duct.

[0009]

However, in such a conventional intake duct mounting structure for a straddle-type vehicle, it is difficult to provide a sufficient capacity chamber in the intake duct due to space limitations inside the vehicle body. There is a problem that. In addition, even when the chamber is provided, the appearance design parts such as the cover are provided separately from the intake duct, so that the number of parts is increased and the production cost is increased.

[0010] The present invention has been made in view of such technical problems, and an object of the present invention is to reduce the restrictions on the space inside the vehicle body and to provide a cover for covering the intake duct. An object of the present invention is to provide a saddle-ride type vehicle that is not required, and can simplify the structure and reduce the cost by reducing the number of parts.

[0011]

According to a first aspect of the present invention, there is provided a saddle-ride type vehicle comprising: a front fender provided at a front portion of a vehicle body; and a rear fender provided at a rear portion of the vehicle body. An engine mounted in the center of the vehicle body, an air cleaner mounted behind the engine and connected to the engine, a fuel tank mounted above the engine, and a seat mounted behind the fuel tank When,
An intake duct extending from the air cleaner to a front upper portion of the vehicle body through a side of an engine and having a front end opening located inside the front fender, wherein the intake duct comprises:
It has a cylindrical duct portion extending from the front end opening and a chamber portion having a vertically elongated box-shaped cross section whose cross-sectional area is expanded from the duct portion, and a front fender, a rear fender and a fuel are formed by an outer surface of the chamber portion itself. It is characterized in that a part of the side of the vehicle body surrounded by the tank is formed.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a concave portion is formed on a lower surface of the chamber portion, and a cross-sectional reduction portion is formed at an intermediate position in the front-rear direction of the chamber portion. By making it possible to access the equipment inside the vehicle body through the recess, and by forming a front expansion part and a rear expansion part before and after the reduced section, the maintenance and inspection of the equipment inside the vehicle body is further performed. An object of the present invention is to provide a straddle-type vehicle that can be easily performed.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals indicate the same or corresponding parts throughout the drawings. FIG. 1 is a left side view of an embodiment of a straddle-type vehicle to which the present invention is applied, and FIG.
1 is a plan view of a saddle-ride type vehicle. 1 and 2,
Frame (body frame) 1 consisting of a pipe welded structure
The engine 11 is mounted in the center of the
Left and right front wheels (steering wheels) 12 and 12 are suspended on both sides of a front portion of the vehicle 10, and left and right rear wheels (normally driving wheels) 13 and 13 are suspended on a rear portion of the frame 10.

A vertically extending steering shaft 14 is supported at the front of the frame 10, and a bar handle 15 is fixed to the upper end of the steering shaft 14. A tie rod (not shown) leading to the front wheels 12, 12 is connected. The left and right front wheels 12 are independently suspended on both sides of the front portion of the frame 10.

The left and right rear wheels 13, 13 are suspended by a swing arm 16 and a load carrying cushion unit 17, and are driven by the engine 11 through a transmission mechanism (not shown) such as a drive shaft or a drive chain in the illustrated example. Is done. This transmission mechanism is connected to a differential gear (not shown) that drives the left and right rear wheels 13, 13.

A front carrier 18, a fuel tank 19, a seat 20, and a rear carrier 21 are mounted on the upper portion of the frame 10 from the front, and footboards (steps) 22 are mounted on both lower sides of the frame 10. The frame 10 includes a front fender 23, a tank cover 24, a rear fender 25, and the like.
Covers made of molded articles such as plastic are detachably attached. The driver straddles the seat 20,
The driver puts his foot on the footboard 22 and grips the bar handle 15 (specifically, the grip portion) to drive.

1 and 2, a carburetor 27 is connected to an intake port of the engine 11 mounted on the center of the vehicle body. The carburetor 27 has an intake duct (downstream intake duct) 2.
The air cleaner 29 is connected via the air cleaner 8. Further, a long intake duct (upstream intake duct) 30 extending to the upper front part of the vehicle body is connected to the entrance of the air cleaner 29. The distal end opening 31 of the upstream intake duct 30 forms an air intake.

The air intake port 31 is disposed so as to open rearward in a region where the air inside the front upper part of the vehicle body is relatively clean, and in the example shown in the figure, a fuel tank attached to the front upper part of the vehicle body frame 10 is provided. The front fender 23 is located at the front side of the front 19. Thus, a saddle-ride type including the engine 11 mounted in the center of the vehicle body, the air cleaner 29 connected to the engine via the carburetor 27, and the long intake duct 30 extending from the air cleaner to the upper front part of the vehicle body. A vehicle is configured.

FIG. 3 is a side view of the long upstream intake duct 30 when the vehicle is mounted on the vehicle. FIG. 4 is a plan view of the intake duct 30 shown in FIG. 3 when the vehicle is mounted on the vehicle. 3 and 4, in the straddle-type vehicle according to the embodiment of the present invention, the intake duct (upstream intake duct) 30 has a change (expanded change) in the flow path cross section in the middle of the intake duct 30. 32 is provided, and a part of the side surface of the vehicle body is formed by the surface of the chamber 32 itself. Further, the chamber portion 32 is provided with a cross-sectional reduction portion 33 for enabling access to accessories inside the vehicle body such as a vaporizer. Further, in the chamber portion 32, a front expansion portion 45 and a rear expansion portion 46 having different cross sections are formed before and after the cross section reduction portion 33.

FIG. 5 is a sectional view taken along line 5-5 in FIG. 3, FIG. 6 is a sectional view taken along line 6-6 in FIG. 3, and FIG. FIG. 8 is a cross-sectional view of the cross-section reduced portion 33 taken along a line 7-7 in FIG. 3, and FIG. 8 is a cross-sectional view of the rear expanded portion 46 taken along a line 8-8 in FIG. 3 and 4, the upstream intake duct 30 of the present embodiment has a long snorkel shape as a whole, and a relatively long upstream portion 30A and a relatively short upstream portion 30A at a position A near the air cleaner 29 in the middle thereof. It is divided into a downstream portion 30B, and the ends of the two portions 30A and 30B are fitted to each other and connected to each other by a sheet metal clamp, or in some cases fixed by welding or brazing, so that an airtight state is obtained. It has a structure that is integrally connected.

3 to 8, a chamber portion 32 is formed in the middle of the intake duct 30 (in this embodiment, the upstream portion 30A) for changing the cross section of the flow path of the intake duct. In the illustrated example, the duct portion of the intake duct 30 has a cylindrical shape with a substantially circular cross section as shown in FIG. 5, and the chamber portion 32 has a box-shaped cross sectional shape as shown in FIGS. I have. The cross-sectional area of the chamber portion 32 is several times the cross-sectional area of the cylindrical duct portion (for example, about twice to about 10 times).
About twice).

As shown in FIG. 3, the chamber section 32 is provided for enabling access to these components when operating functional components such as the carburetor 27 provided inside the vehicle body. A reduced cross section 33 is formed, and by forming the reduced cross section 33, a front expansion section 45 and a rear expansion section 46 having different cross sections as shown in FIGS. 6 and 8 are formed before and after that. 3 and 4, a drain 35 capped with a plug member such as a rubber crow mouth (one-way valve) is provided at a relatively low range of the long intake duct 30 extending to the upper front part of the vehicle body. I have.

An opening end (small) 37 for connecting a breather tube 36 of a transmission case of the engine 11 is formed at a position of the intake duct 30 near the air cleaner 29. That is, in the present embodiment, the inside of the transmission case of the engine 11 is communicated with the inside of the intake duct 30 to absorb pressure fluctuations in the transmission case.

FIG. 9 is a longitudinal sectional view taken along line 9-9 in FIG. 1, FIG. 10 is a longitudinal sectional view taken along line 10-10 in FIG. 1, and FIG. FIG. 12 is a longitudinal sectional view taken along line 11-11. 1, 2, 9, and 10, a box-shaped space 38 that is open frontward is formed on the lower surface of the front fender 23 at the upper front of the vehicle body, and the long intake duct 30 extends into the space 38. And the intake duct 3
The front end opening (air intake port) 31 of 0 is opened backward in this space 38.

The space 38 includes the front fender 23
, A dustproof bottom plate 39 and dustproof side plates 40 and 40 fixed to the frame 10, and a front end face of the fuel tank 19. The intake duct 30 is disposed such that a front end opening (air intake port) 31 faces the front end face of the fuel tank 19 in the space 38. In FIG. 9, reference numeral 42 denotes a strut-type cushion unit for front wheel suspension, and reference numeral 43 denotes a mud plate for preventing muddy water or dust rolled up by the front wheel 12 from entering the vehicle body.

The intake duct 30 is shown in FIGS.
As shown in FIG. 11, the surface of the chamber portion 32 (the outer surface when the vehicle is mounted) 34 itself is assembled so as to form a part of the vehicle body side surface (the outer surface of the vehicle body).
That is, with the intake duct 30 mounted on the vehicle, the surface 34 of the chamber 32 forms an outer surface that is substantially continuous with the surfaces of the adjacent front fender 23, tank cover 24, and rear fender 25.
2 itself is used as an external design member. In FIG. 11, reference numeral 44 denotes a side cover attached to a position symmetrical with respect to the chamber 32 of the intake duct 30.

According to the embodiment described above, in a straddle-type vehicle provided with a long intake duct 30 extending from the air cleaner 29 to the upper front part of the vehicle body, the cross section of the flow passage is changed in the middle of the intake duct 30. The chamber portion 32 is provided to prevent the pulsation of the intake air,
Since a part of the vehicle body side surface (outer surface) is formed by the surface of the body 2 itself, a good appearance design can be ensured without providing a cover for covering the intake duct 30.
Restrictions on the space inside the vehicle body can be reduced, the cross-sectional area of the chamber portion 32 can be sufficiently ensured, and the structure can be simplified and the cost can be reduced by reducing the number of parts.

The vaporizer 27 is provided in the chamber 32.
The provision of a reduced cross section 33 to allow access to the equipment inside the vehicle body, such as the intake duct, which is inferior in detachability compared to a simple cover, makes it easy to perform maintenance and inspection of the equipment even if it is an exterior part. It can be carried out. Further, since the cross-section reducing portion 33 is provided in the chamber portion 32, the expansion portions 45 and 46 having different cross-sections are formed before and after the cross-section reducing portion 33, so that the pulsation of the intake air can be more easily and effectively prevented.

[0029]

As is apparent from the above description, according to the invention of claim 1, the front fender provided at the front of the vehicle body and the rear fender provided at the rear of the vehicle body. An engine mounted in the center of the vehicle body, an air cleaner mounted behind the engine and connected to the engine, a fuel tank mounted above the engine, and a seat mounted behind the fuel tank When,
An intake duct extending from the air cleaner to a front upper portion of the vehicle body through a side of an engine and having a front end opening located inside the front fender, wherein the intake duct comprises:
It has a cylindrical duct portion extending from the front end opening and a chamber portion having a vertically elongated box-shaped cross section whose cross-sectional area is expanded from the duct portion, and a front fender, a rear fender and a fuel are formed by an outer surface of the chamber portion itself. The structure that forms a part of the side of the vehicle body surrounded by the tank can reduce the restrictions on the space inside the vehicle body, eliminating the need for covers to cover the intake duct and reducing the number of parts In addition to the simplification of the structure and the cost reduction, the side wall of the vehicle body is formed by the chamber itself, so that the vertical dimension of the chamber can be easily increased and the intake pulsation can be prevented. It is possible to easily provide a chamber part with sufficient capacity,
A straddle-type vehicle capable of forming a chamber having an excellent function as a cover by enlarging the size of the chamber in the up-down direction and the front-rear direction to cover the inside of the vehicle body over a wide range.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, a concave portion is formed on the lower surface of the chamber portion, and a cross-sectional reduction portion is formed in the front-back direction of the chamber portion. In addition, in addition to the effect of the above-mentioned claim 1, in addition to the effect of claim 1, it is possible to access to the equipment inside the vehicle body through the concave portion, and to form a front extension portion and a rear extension portion before and after the cross-section reduction portion. The recess on the lower surface allows easy access to equipment inside the vehicle body even when the side of the vehicle body is formed in the chamber, and specially designed front and rear extensions that are effective in preventing pulsation A straddle-type vehicle that can be formed without the need for a simple member and that can easily perform maintenance and inspection of equipment inside the vehicle body is provided.

[Brief description of the drawings]

FIG. 1 is a left side view of an embodiment of a saddle-ride type vehicle to which the present invention is applied.

FIG. 2 is a plan view of the straddle-type vehicle shown in FIG.

FIG. 3 is a side view of the upstream intake duct in FIG. 1 in a state of being mounted on a vehicle.

FIG. 4 is a plan view of the intake duct of FIG. 3 in a state of being mounted on a vehicle.

FIG. 5 is a sectional view of the cylindrical duct section taken along line 5-5 in FIG. 3;

FIG. 6 is a sectional view of the front extension taken along line 6-6 in FIG. 3;

FIG. 7 is a cross-sectional view of the cross-sectional reduction portion along line 7-7 in FIG.

FIG. 8 is a cross-sectional view of the rear extension along line 8-8 in FIG. 3;

FIG. 9 is a longitudinal sectional view taken along line 9-9 in FIG. 1;

FIG. 10 is a longitudinal sectional view taken along line 10-10 in FIG. 1;

FIG. 11 is a longitudinal sectional view taken along line 11-11 in FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Body frame 11 Engine 12 Front wheel 13 Rear wheel 15 Handle 19 Fuel tank 20 Seat 23 Front fender 24 Tank cover 25 Rear fender 27 Vaporizer 28 Downstream intake duct 29 Air cleaner 30 Upstream intake duct 31 Air intake 32 Chamber part 33 Cross section reduction Part 34 Surface of chamber part 38 Space 39 Dustproof bottom plate 40 Dustproof side plate 41 Front end face of fuel tank 43 Mudproof plate 44 Side cover 45 Front extension part 46 Rear extension part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02M 35/10 F02M 35/10 301R

Claims (2)

(57) [Claims] A front fender provided at a front portion of the vehicle body; a rear fender provided at a rear portion of the vehicle body;
An engine mounted in the center of the vehicle body, an air cleaner mounted behind the engine and connected to the engine, a fuel tank mounted above the engine, and a seat mounted behind the fuel tank; An intake duct extending from the air cleaner to a front upper portion of the vehicle body through a side of an engine and having a tip opening located inside the front fender, wherein the intake duct is a cylindrical duct extending from the tip opening. Section and a chamber part having a vertically long box-shaped cross section whose cross-sectional area is expanded from the duct part. The outer surface of the chamber part itself includes a front fender, a rear fender, and a fuel tank. A straddle-type vehicle characterized by forming a part. 2. A recess is formed in the lower surface of the chamber portion, and a cross-section reduction portion is formed in the middle of the chamber portion in the front-rear direction, thereby enabling access to equipment inside the vehicle body through the recess. The straddle-type vehicle according to claim 1, wherein a front extension portion and a rear extension portion are formed before and after the cross-section reduction portion.