JPH0783136A - Fuel supplying device for vertical gasoline engine - Google Patents

Abstract

PURPOSE:To suppress vapor lock by supporting a fuel supplying pump while interposing the fuel supplying pipe between a fuel leading pipe which is protruded from a carburetor and a fuel discharging pipe which is protruded from the fuel supplying pump while arranging the fuel supplying pump just under the carburetor. CONSTITUTION:A carburetor 3 is installed on a cylinder head 2 while assembling the cylinder head 2 on the upper part of a cylinder block 1. A fuel supplying pipe 7 is interposed between a fuel leading pipe 4 which is protruded from the carburetor 3 and a fuel discharging pipe 6 which is protruded from a fuel supplying pump 5. In this case, the fuel supplying pump 5 is arranged just under the carburetor 3. The fuel supplying pipe 7 is interposed and supported between the fuel leading pipe 4 and the fuel discharging pipe 6. On the other hand, the input part 12 of the fuel supplying pump 5 installed on the crank chamber wall 8 of the cylinder block 1 is forced to abut on the pump interlocking cam 11 of a balancer shaft 10 which is mounted in a crank chamber 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for a vertical gasoline engine, and more particularly to a system capable of suppressing vapor lock in the fuel supply pipe and reducing the number of parts.

[0002]

2. Description of the Related Art As a conventional fuel supply device for a vertical gasoline engine, there is one having the following basic structure as in the present invention. That is, the cylinder head is assembled on the upper part of the cylinder block, the carburetor is attached to the cylinder head, and the fuel supply pipe is interposed between the fuel introduction pipe protruding from the carburetor and the fuel discharge pipe protruding from the fuel supply pump. Then there is one configured.

In the fuel cell having such a basic structure, the fuel from the fuel tank is supplied to the carburetor through the fuel supply pipe by the pumping force of the fuel supply pump.

By the way, in this type, conventionally, the fuel supply pump has been mounted either side by side with the carburetor on the cylinder head, or obliquely below the carburetor on the crank chamber wall of the cylinder block. . In the former case, the fuel supply pipe is installed horizontally. In the latter case, the distance between the carburetor and the fuel supply pump becomes long, so the fuel supply pipe is
Along the wall surface of the cylinder block, it has a complicated bent shape that avoids various parts such as a governor lever, and is supported by a support tool such as a clamp on the cylinder block.

[0005]

The above-mentioned conventional techniques have the following problems. When the fuel supply pipe is installed horizontally, the vapor generated inside does not come off due to the levitation force.
It is easy to collect inside. Also, when the fuel supply pipe has a complicated bent shape, the pipeline shape is complicated and the pipeline dimension is long, so the pipeline resistance increases, and the vapor generated inside is difficult to come off, It is easy to collect inside. As described above, in all of the conventional ones, vapor easily accumulates in the fuel supply pipe, which causes vapor lock.

Since the fuel supply pipe having a complicated bent shape is long and heavy, a supporting tool such as a clamp is required, which causes a large number of parts.

An object of the present invention is to provide a fuel supply device for a vertical gasoline engine, which can suppress vapor lock in the fuel pumping pipe and reduce the number of parts.

[0008]

[Means for Solving the Problems]

(First Invention) As shown in FIG. 1, a first invention is to mount a cylinder head 2 on an upper portion of a cylinder block 1,
A carburetor 3 is attached to the cylinder head 2, and a fuel supply pipe 7 is interposed between a fuel introduction pipe 4 protruding from the carburetor 3 and a fuel discharge pipe 6 protruding from the fuel supply pump 5. The fuel supply device for a vertical gasoline engine is characterized by the following.

That is, as illustrated in FIG. 1, the fuel supply pump 5 is attached to the cylinder block 1 immediately below the carburetor 3, and the fuel introduction pipe 4 of the carburetor 3 and the fuel discharge pipe 6 of the fuel supply pump 5 are connected. The fuel supply pipe 7 interposed therebetween is supported.

(Second Invention) As shown in FIG. 1, the second invention is a balancer in which, in the first invention, the fuel supply pump 5 is attached to the crank chamber wall 8 of the cylinder block 1 and installed in the crank chamber 9. A pump interlocking cam 11 is provided on the shaft 10, and the input portion 12 of the fuel supply pump 5 is brought into contact with the pump interlocking cam 11.

[0011]

[Operation and effect of the invention]

(First Invention) The first invention has the following actions and effects, as illustrated in FIG. The fuel supply pipe 7 is oriented vertically. Also, the distance between the carburetor 3 and the fuel supply pump 5 becomes shorter,
Since the total length of the fuel supply pipe 7 becomes short, the conduit resistance becomes small. Therefore, the vapor generated in the fuel supply pipe 7 quickly floats and escapes to the carburetor 3 side, and the vapor lock in the fuel supply pipe 7 is suppressed.

Since the overall length of the fuel supply pipe 7 is shortened and the weight thereof is reduced, it is possible to support it only by the fuel introduction pipe 4 of the carburetor 3 and the fuel discharge pipe 6 of the fuel supply pump 5, and to support a clamp or the like. Since no tools are needed,
The number of parts is reduced.

(Second Invention) As shown in FIG. 1, the second invention has the following actions and effects in addition to the above-mentioned items. Since the balancer shaft 10 is also used as the cam shaft of the pump interlocking cam 11, a dedicated cam shaft is not required, so that the number of parts is reduced and the engine is made compact.

[0014]

Embodiments of the present invention will be described with reference to the drawings.
1 to 3 are views for explaining an embodiment of the present invention. The engine of this embodiment is a diagram for explaining a vertical overhead cam type water-cooled two-cylinder gasoline engine.

The structure of this engine is as follows. That is, as shown in FIG. 2, the cylinder head 2 is assembled to the upper portion of the cylinder block 1, the head cover 13 is assembled to the upper portion thereof, and the gear case 14 and the belt case 15 are assembled to the front side portion of the cylinder block 1. . A cooling fan 1 is provided on the front side of the belt case 15.
6 is attached, and a radiator 17 is arranged on the front side thereof. The upper portion of the cylinder block 1 is configured as a cylinder portion 18, and the lower portion is configured as a crank chamber 9. As shown in FIG. 3, a crankshaft 19 is installed in the center of the crank chamber 9, and two secondary balancer shafts 10 parallel to the crankshaft 19 are provided on both sides of the crankshaft 19.
・ 10 is installed.

The structure of the fuel supply system for this engine is as follows. That is, as shown in FIG. 2, the single carburetor 3 is attached to the front-rear center of the left side wall of the cylinder head 2. As shown in FIG. 1, the carburetor 3 is attached to the cylinder head 2 via only an insulator 36. The engine is not provided with an intake manifold, and the pair of intake ports (not shown) in the cylinder head 2 are integrally formed as a V-shaped branch passage with the start ends thereof joined together. Carburetor 3
A fuel supply pipe 7 is interposed between the fuel introduction pipe 4 protruding from the fuel supply pipe 5 and the fuel discharge pipe 6 protruding from the fuel supply pump 5.

In this embodiment, in order to suppress vapor lock in the fuel supply pipe 7 and reduce the number of parts, the fuel supply device has the following structure. That is, as shown in FIGS. 1 and 2, the fuel supply pump 5 is attached to the cylinder block 1 directly below the carburetor 3. Then, as shown in FIG. 2, the fuel introduction pipe 4 is projected downward from the front side of the carburetor 3, and the upper end of the fuel supply pipe 7 is fitted to the lower end of the fuel supply pipe 7. The fuel supply pipe 5 is fitted in a fuel discharge pipe 6 projecting from the fuel supply pump 5, and the fuel introduction pipe 4 of the carburetor 3 and the fuel discharge pipe 6 of the fuel supply pump 5
And, the fuel supply pipe 7 interposed between them is supported.

According to this structure, the fuel supply pipe 7 is oriented vertically. Further, the distance between the carburetor 3 and the fuel supply pump 5 becomes short, and the fuel supply pipe 7
Since the total length of the pipe becomes shorter, the pipe resistance becomes smaller. Therefore, the vapor generated in the fuel supply pipe 7 quickly floats and escapes to the carburetor 3 side, and the vapor lock in the fuel supply pipe 7 is suppressed. Further, since the total length of the fuel supply pipe 7 is shortened and the weight thereof is reduced, it can be supported only by the fuel introduction pipe 4 of the carburetor 3 and the fuel discharge pipe 6 of the fuel supply pump 5, and a support tool such as a clamp. Is unnecessary, the number of parts is reduced.

Further, in this embodiment, as shown in FIG. 3, a pump interlocking cam 11 is provided in the center portion of the left balancer shaft 10 in the front-rear direction, and as shown in FIG. The input part 12 of the supply pump 5 is abutted. Therefore, the balancer shaft 10 is also used as the cam shaft of the pump interlocking cam 11, and a dedicated cam shaft is not required, so that the number of parts can be reduced and the engine can be made compact.

Further, in this embodiment, as shown in FIG. 3, a bearing boss 21 is provided so as to project from the center portion in the left-right direction of the front side wall of the crank chamber 9 toward the front thereof, and the tip end portion of the crank shaft 19 is provided there. Is inserted, and the crank gear 22 is externally fitted and fixed thereto. Further, balancer gears 23, 23 are externally fitted and fixed to the front portions of both balancer shafts 10, 10, and these are meshed with the crank gear 22, respectively. Crank gear 22 and both balancer gears 23, 23
Are accommodated in the gear case 14, and both balancer shafts 10 and
Each tip of 10 is borne by bearings 24, 24 provided on the gear case 14. A governor weight 25 is attached to the rear surface of the left balancer gear 23, and a governor sleeve 26 is externally fitted to the balancer shaft 10 behind the balancer shaft 25 so as to be slidable back and forth.

According to such a structure, the governor weight 25 is integrated with the secondary balancer shaft 10 and is rotatably linked with the crankshaft 19 at its double speed, and the response sensitivity of the governor weight 25 is enhanced. can do.
Therefore, on the side of the bearing boss 21 of the crankshaft 19,
Using the dead space located on the rear side of the balancer gear 23, the governor weight 25 and the governor sleeve 26 can be arranged without difficulty. Further, since the balancer shaft 10 and the balancer gear 23 also serve as the guide shaft of the governor sleeve 26 and the support body of the governor weight 25, the dedicated parts thereof are not required, the number of parts is reduced, and the engine can be made compact.

Further, in this embodiment, as shown in FIG. 3, a gear case 14 is provided with a lubricating oil pump 27, and an input shaft 28 thereof is connected to the tip of the left balancer shaft 10 via an Oldham joint 29. The interlocking structure is simplified.

Further, in this embodiment, as shown in FIG. 2, a pair of spark plugs 30, 30, an air cleaner 31,
Carburetor 3, fuel supply pump 5, speed control lever 32,
The governor lever 33, the oil level gauge 34, and the oil element 35 are gathered on the left side of the engine so that the engine can be easily maintained.

Although the contents of the embodiment of the present invention are as described above, the present invention is not limited to the contents of the above embodiment. Although the above embodiment has described the vertical overhead cam type water-cooled two-cylinder gasoline engine, the present invention can be applied to a vertical gasoline engine. Therefore, it can be applied to various types of engines such as an overhead valve engine, an air-cooled engine, a liquid-cooled engine, a single-cylinder engine, and a multi-cylinder engine having two or more cylinders.

[Brief description of drawings]

FIG. 1 is a partially longitudinal front view of a main part of an engine according to an embodiment of the present invention.

2 is a side view of the engine of FIG. 1. FIG.

3 is a cross-sectional plan view of the engine of FIG.

[Explanation of symbols]

1 ... Cylinder block, 2 ... Cylinder head, 3 ... Carburetor, 4 ... Fuel introduction pipe, 5 ... Fuel supply pump, 6 ...
Fuel discharge pipe, 7 ... Fuel supply pipe, 8 ... Crank chamber wall,
9 ... Crank chamber, 10 ... Balancer shaft, 11 ... Pump interlocking cam, 12 ... Input part.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Inoue 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Co., Ltd.

Claims (2)

[Claims] 1. A cylinder head (2) is attached to an upper part of a cylinder block (1), a carburetor (3) is attached to the cylinder head (2), and a fuel introduction pipe (4) protruding from the carburetor (3). A fuel supply system for a vertical gasoline engine, comprising a fuel supply pipe (7) between a fuel discharge pipe (6) protruding from a fuel supply pump (5), and a carburetor (3) Cylinder block (1) immediately below
A fuel supply pump (5) is attached to the fuel supply pipe (4) of the carburetor (3) and a fuel discharge pipe (6) of the fuel supply pump (5).
A fuel supply device for a vertical gasoline engine, characterized in that a fuel supply pipe (7) interposed therebetween is supported. 2. The fuel supply device for a vertical gasoline engine according to claim 1, wherein the fuel supply pump (5) is attached to the crank chamber wall (8) of the cylinder block (1), and the fuel is supplied in the crank chamber (9). A vertical type characterized in that a pump interlocking cam (11) is provided on an installed balancer shaft (10), and the input part (12) of the fuel supply pump (5) is brought into contact with the pump interlocking cam (11). Fuel supply device for gasoline engine.