JPS61139576A - Saddling type car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention A0 Objective of the Invention (1) Industrial Application Field The present invention comprises a head pipe, a main tube extending rearward from the head pipe, and a main tube extending rearward downward from the head pipe. The present invention relates to a straddle-type vehicle in which an engine is mounted at the bottom of a body frame that includes a down tube.

(2) Conventional technology A straddle-type vehicle, such as a three-wheeled buggy, may travel in a flood control area, and if the opening of the breather tube is at a relatively low position, flood control may leak from the breather tube into the engine. Penetration and deterioration of lubricating oil. Therefore, in the past, as disclosed in, for example, Japanese Utility Model Application Publication No. 51-39711, a breather tube extending from the engine crankcase was communicated with the body frame, and the upper part of the body frame was opened to the atmosphere. .

(3) Problems to be Solved by the Invention However, in the above-mentioned prior art, the breather tube is connected to a cross member connecting a pair of center pipes extending downward from the main tube, and the upper part of the center pipe is connected to the atmosphere. Since the opening is provided, it is difficult to effectively transfer heat from the engine body to the opening and the tip of the breather tube. For this reason, to prevent the opening and the tip of the breather tube from freezing during the coldest months,
It was necessary to cover it with body structural parts such as air cleaners and side covers.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a straddle-type vehicle that prevents water from entering the breather tube and from freezing.

B1 Structure of the Invention (1) Means for Solving the Problems According to the present invention, the engine is arranged with its cylinder section along the down tube, and the breather tube extending from the head cover of the engine is arranged along the down tube. The downtube communicates with the inside of the tube, and has an opening open to the atmosphere at the upper end of the downtube.

(2) Brie extending from the head cover of the working engine
'The tube communicates with the inside of the down tube, and the upper end of the down tube is provided with an opening open to the atmosphere, so that the intrusion of salt water etc. into the breather tube is prevented as much as possible. Moreover, since the breather tube and the down tube are close to the cylinder section of the engine, it is possible to remove ice at the opening and the tip of the breather tube by heat radiation from the cylinder section.

(3) Embodiment Below, an embodiment of the present invention will be described with reference to the drawings. First, in FIGS. 1 and 2, a body frame 2 of a straddle-type vehicle 1 has a single front wheel A pair of left and right rear wheels Wr and Wr' are supported at the rear of f-1, and an engine E is mounted in the center of the vehicle body frame. Also each wheel W
Very low pressure tires, commonly called balloon tires, are mounted on f+' Wr and Wr'.

The front wheel Wf is pivotally supported by a front fork 3 that is steerably supported at the front end of the vehicle body frame 2, and both rear wheels Wr, Wr
' is a lug 4 (third lug) provided at the rear end of the body frame 2
(see figure). Furthermore, a fuel tank 5 disposed above the engine E and a saddle 6 continuing to the rear end of the fuel tank 5 are mounted on the upper part of the vehicle body frame 2.

The structure of the vehicle body frame 2 will be explained with reference to FIG. 3. A main tube 8 is welded to the upper part of the head pipe 7 that supports the front fork 3, and a down tube 9 is welded to the lower part of the head pipe 7. The main tube 8 extends backward and downward from the head pipe 7 at a gentle slope.
The down tube 9 extends rearward and downward from the head pipe 7 at a steep slope. A pair of left and right engine support bones 10.1'O are welded to the rear ends of both tubes 8 and 9. A pair of saddle support bones 11.11 for supporting the saddle 6 are welded to the upper portions of both engine support bones 10 and 10 in a substantially horizontal state, and further between the saddle support bones ii and it and the engine support bones 10 and 10. A reinforcing bone 12.12 is welded to.

The engine E is mounted at the bottom of the vehicle body frame 2. That is, the engine E is attached to the vehicle body frame 2 by fixing the crankcase 16 with the oil pan 20 at the bottom to the bracket 13 provided at the bottom of the down tube 9 and the brackets 14 and 15 provided to the engine support frame 10. It will be installed. In addition, the engine E is arranged such that the cylinder portion 17 extending upward from the crankcase 16 is close to and substantially parallel to the down tube 9.

An air cleaner 21 is supported near the joint between the engine support frame 10 and the saddle support frame 11, and this air cleaner 21 is connected to the cylinder section 17 of the engine E via an intake pipe 23 equipped with a carburetor 22. Cylinder part 1
An exhaust pipe 24 extends from 7.

A lug 4 is provided at the rear end of the engine support frame 10, and the driving force of the engine E is transmitted via a chain transmission device 25 to the rear wheels Wr, Wr' supported by the lug 4.

A breather tube 26 extends from the upper part of the cylinder section 17 of the engine E, that is, from the head cover 19, and this breather tube 26 extends upward and is connected to a connecting pipe 27 provided on the down tube 9.

In FIG. 4, an opening 2 is formed on the upper wall of the upper end of the down tube 9 at a position above the upper surface of each wheel Wf, Wr, Wr'.
8 is provided. On the other hand, substantially triangular reinforcing plates 29.29 are welded from both sides to the connecting portion of the main tube 8 and down tube 9 to the head vibe 7, and the opening 28 is located between both reinforcing plates 29.29. It is provided on the down tube 9 facing toward the front. Furthermore, both reinforcing plates 29, 29 are provided with air suction ports 30, 30, respectively.

In FIG. 5, the rear end, that is, the lower end of the down tube 9 is closed by a closing member 32 having a connecting pipe portion 31 with a small diameter. Moreover, the crank case 16 is connected to the connecting pipe portion 31.
A return tube 33 leading to the lower part of is connected.

Referring again to FIG. 3, the inlet of the air cleaner 21 is connected to the conduit 3.
4 to the rear end of the main tube 8. Further, a suction hole 35 is provided in the front part of the main tube 8 facing between both reinforcing plates 29 and 29.

Next, to explain the operation of this embodiment, the breather tube 26 is connected from the navel cover 19 at the upper part of the engine E to the down tube 9, and is connected to each wheel Wf, WrXWr.
' Since the opening 28 that opens to the atmosphere is provided at the upper end of the down tube 9 which is higher than the top surface of the down tube, it is opened to the atmosphere at a higher position than the conventional one.
It is possible to prevent tide water from entering as much as possible when driving in a tide water area. Moreover, the opening 28 has reinforcing plates 29 on both sides.
．． 29, the intrusion of dust is also prevented as much as possible.

In addition, the opening 28 is blocked off from both sides by reinforcing plates 29 and 29, and the tip of the breather tube 26 is open toward the inside of the down tube 9, so snow and ice do not get inside the down tube 9. Breather tube 26
It is possible to prevent not only the tip of the opening 28 from freezing as much as possible, but also the opening 28 from freezing. Further, the opening 28 and the breather tube 26 are located close to the cylinder section 17 of the engine E, and can prevent ice from forming due to heat radiation from the cylinder section 17.

Furthermore, the gas guided into the down tube 9 from the breather tube 26 contains a lubricating oil mist, which is lower in temperature than the down tube 9 than the engine E.
Heat is removed inside the tube, and the liquid collides with the inner surface of the down tube 9 to promote liquefaction.It is sufficiently liquefied as it descends along the inner wall of the down tube 9, and then flows from the return tube 33 through the crankcase 16 to the oil pan 20. be returned to.

Therefore, it is possible to reduce the amount of lubricating oil consumed.

Effects of the C0 Invention As described above, according to the present invention, the engine is arranged with its cylinder section along the down tube, and the breather tube extending from the head cover of the engine is communicated with the inside of the down tube. Since the upper end of the tube is provided with an opening that is open to the atmosphere, it is possible to prevent salt water from entering the breather tube as much as possible, and the opening and the tip of the breather tube can be used to dissipate heat from the engine cylinder. Freezing can be prevented by placing it close to the area that can be heated.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a plan view of a straddle-type vehicle, FIG. 2 is a side view of FIG. 1, FIG. 3 is an enlarged side view of main parts, and FIG. 3 is an enlarged sectional view taken along the line rv-Lrv in FIG. 3, and FIG. 5 is an enlarged sectional view of the V section in FIG. ■...Saddle type vehicle, 2...Vehicle frame, 7...
Head pipe, 8... Main tube, 9... Down tube, 17... Cylinder part, 19... Head cover, 26... Breather tube, 28... Opening E... Engine patent 1986-13957G (4) Procedures (Hoshosho (Method)

Claims (1)

[Claims] At the lower part of the vehicle body frame, which includes a head pipe, a main tube extending rearward from the head pipe, and a down tube extending rearward downward from the head pipe,
In a straddle-type vehicle equipped with an engine, the engine is arranged with its cylinder section along the down tube, and a breather tube extending from the head cover of the engine is communicated with the down tube,
A straddle-type vehicle characterized by having an opening open to the atmosphere at the upper end of the downtube.