JPS636435Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a float device installed in a carburetor for supplying an air-fuel mixture to an internal combustion engine.

In a float device for a carburetor, fuel pumped from a fuel source is introduced into a float chamber through a fuel inlet, and the fuel inlet is linked to a float that moves up and down in response to rises and falls in the fuel liquid level in the float chamber. It is opened and closed by a valve member. Therefore, the fuel in the float is guided to the fuel nozzle of the carburetor through a fuel guide passage whose one end is open to the float chamber, and is supplied from the nozzle to the engine depending on the operating state of the engine. At about the same time, the valve member is operated to replenish the float chamber with fuel, thereby ensuring a stable supply of fuel from the nozzle to the engine.

By the way, when the opening to the float chamber, which is one end of the fuel guide passage, is located at a position offset from the center of the float chamber to one side, the carburetor is tilted so that the side is upward. Then, smooth flow of fuel from the float chamber to the fuel guide passage may be blocked. Therefore, in order to enable stable fuel supply to the engine regardless of the inclination of the carburetor, the one end of the fuel guide passage must be connected to the center of the bottom of the float chamber. It is necessary to open the float chamber at a certain point.

However, in a float device in which a float chamber is provided in the lower part of the carburetor main body, the fuel guide passage is connected to the float chamber so that the one end of the fuel guide passage is opened to the float chamber at the bottom central portion of the float chamber. If the outer side of the float chamber is detoured from below, the length of the fuel guide passage becomes large, which has the drawback of deteriorating the operational response performance of the engine.

Therefore, an object of the present invention is to provide a float device that enables stable fuel supply to an internal combustion engine regardless of the inclination of the carburetor and does not cause a decrease in the operational response performance of the engine. .

In the present invention, a shaft member is disposed in the center of a float chamber formed in the lower part of the carburetor body, and passes through the float in the vertical direction to allow vertical movement of the float disposed in the float chamber. a member extending along its longitudinal axis and having a lower end open near the bottom of the float chamber at a side of the shaft member;
Further, a fuel guide passage is formed whose upper end is open to the outside of the float chamber so as to communicate with a fuel nozzle provided in the carburetor body, and an air vent passage is formed in the shaft member parallel to the guide passage. , one end of the air vent passage is open to the upper part of the float chamber near the upper end of the shaft member, and the other end is opened to the atmosphere at the lower end of the shaft member.

According to the present invention, since the air vent passage opens into the float chamber at the center of the float chamber, even if the carburetor is tilted in either direction when the fuel level is relatively high, Fuel does not flow into the air vent passage, and clogging of the air vent passage can be prevented;
Fuel can be smoothly supplied through the fuel guide passage.

The features of the present invention will become clearer from the following description of the illustrated embodiments.

The float device 10 according to the present invention is provided at the lower part of the main body of the carburetor 12, as shown in FIG. In the illustrated example, the carburetor 12 is a conventionally well-known rotary throttle valve type carburetor which includes a generally cylindrical rotary throttle valve within the carburetor body, although the details thereof are omitted.

Float device 10 includes a housing 16 coupled to the carburetor body and cooperating with a lower surface of the body to define a float chamber 14 in the lower portion of the carburetor body;
a float 18 disposed within the float chamber 14;
A valve member 20 is included. Although not shown, the housing 16 is provided with a mouthpiece 22 connected to a conventionally well-known fuel pump, and a fuel inlet 24 of the mouthpiece.
Fuel is introduced into the float chamber 14 through the. The base 22 is provided with a guide portion 26 for receiving the valve member 20 movably toward and away from the inlet 24 . The valve member 20 allows fuel to flow into the float chamber 14 through the side of the valve member 20 when its tip is separated from the opening edge of the inlet 24 .

In the illustrated example, a toggle mechanism is used as the coupling mechanism 30 for operating the valve member 20 by the movement of the float 18, which moves up and down in accordance with the rise and fall of the fuel level 28 in the float chamber 14.

The toggle mechanism 30 includes first and second arm members 32 and 34 disposed above the float 18, and one end of the first arm member 32 is swingably supported by the housing 16 via a pivot 36. ing. One end of a second arm member 34 is pivotally attached to the other end of the first arm member 32 via a pin 38 . The pivot portions of both arm members 32 and 34 abut against the upper surface of the float 18 so as to move together with the float. Second arm member 34
The other end is pivotally connected to the upper end of a connecting member 42 via a pin 40, and the lower end of the connecting member is supported by the housing 16 via a pivot 44. A connecting member 42 that is swingable around a pivot 44
engages with the valve member 20 at its intermediate portion in order to move the valve member 20 toward or away from the inlet 24 by its rocking motion.

In the toggle mechanism 30, the buoyant force that the float 18 receives acts as a pushing up force on the pivot joints of both arm members 32 and 34 that contact the upper surface of the float, and this acting force is applied when the first arm member 32 Since it is swingable around the pivot 36, the connecting member 42 is rotated clockwise in the figure around the pivot 44. Further, when the float 18 moves downward due to the lowering of the liquid level, the pivot portions of both arm members 32 and 34 act on the weight of the toggle mechanism 30 and the valve member 20 as the float 18 lowers. The connecting member 42 is moved downward by the fuel hydraulic pressure, and the connecting member 42 is rotated counterclockwise in the figure around the pivot shaft 44. Therefore, in response to the vertical movement of the float 18 as the fuel level 28 changes, the valve member 20 operates to open and close the inlet 24 in order to maintain the fuel level at approximately a prescribed level. be done.

As shown in the figure, an eccentric shaft consisting of, for example, a crank pin 36 is used as the pivot so that the pivot 36 supporting the one end of the first arm member 32 can be displaced in the lateral direction, and the tip thereof is connected to the arm member. By using a screw member 46 that is screwed into the housing 16 from the outside so as to be able to come into contact with the connecting portion with the housing 36, the displacement of the pivot shaft 36 to the left in the figure can be adjusted by operating the screw member 46. This allows the valve member 20 to
The level of the float 18 when the float 18 is in the closed position, ie the specified liquid level, can be adjusted.

As the above-mentioned connection mechanism, a conventionally well-known float arm mechanism or the like can be used instead of the toggle mechanism, but it is possible to adjust the above-mentioned specified liquid level, to reliably open and close the valve member,
Further, in order to prevent large fluctuations in the liquid level, it is desirable to use the toggle mechanism.

The float 18 used in the float device 10 of the present invention has a cylindrical shape as a whole, and has a hollow portion 18a that penetrates in the vertical direction along its axial direction. A shaft member 48 is disposed at the center of the float chamber 14 and extends vertically through the hollow portion 18a to allow the float 18 to move as described above.

The shaft member 48 is supported by a plug 50 made of an elastic material and press-fitted into an opening 16a formed at the bottom of the housing 16. A passage 52 is formed in the shaft member 48 and extends along the longitudinal direction of the shaft member, and the lower end of the passage opens near the center bottom of the float chamber 14 at the lower end side of the shaft member. The upper end of the passage 52 opens to the outside of the float chamber 14 to communicate with a fuel nozzle (not shown) provided in the carburetor body. Therefore, the passage 52
acts as a fuel guide passage for guiding the fuel in the float chamber to the fuel nozzle.

In the illustrated example, in order to form an air vent passage 54 on the outer periphery of the shaft member 48 in cooperation with the shaft member 48, the housing 16 is integrally connected to the bottom of the housing 16 at intervals on the circumferential surface of the shaft member 48. A cylindrical portion 56 is formed which extends into the cylindrical portion. The upper end of the passage 54 opens to the upper part of the float chamber 14 near the upper end of the shaft member 48 . The lower end of the passage 54 is
Communication with the float chamber 14 is blocked by the plug 50, and, as shown in FIG. 2, it is opened to the outside air through a groove 58 formed in the plug 50. Therefore, the air vent passage 54
Since the upper part of the float chamber 14 communicates with the atmosphere through the fuel guide passage 52, the fuel in the float chamber is smoothly guided to the nozzle through the fuel guide passage 52.

The air vent passage 54 described above can be provided inside the shaft member 48 so that the passage is substantially parallel to the fuel guide passage 52, and the cylindrical portion 56 can be formed integrally with the shaft member 48. I can do it.

In the float device 10, the fuel guide passage 52
extends linearly through the center of the float chamber, and its lower end opens into the float chamber 14 near the center bottom of the float chamber. Therefore, the guide passage 52 connects the nozzle with the center bottom of the float chamber 14 Connect with the shortest distance. Therefore, fuel level 28
Since the opening of the guide passage to the float chamber is always immersed in fuel no matter which direction the carburetor is tilted as in the conventional case when the Since it is reliably guided to the nozzle and moreover is guided to the nozzle over the shortest distance, the operational responsiveness of the engine is improved.

Furthermore, since the opening of the air vent passage 54 to the float chamber 14 is located in the center of the float chamber, the air vent passage 54 can be tilted in either direction when the fuel level is relatively high. Since fuel does not easily flow into the air vent passage 54, clogging of the air vent passage 54 can be prevented, and smooth fuel supply can be achieved.

Instead of the air vent passage, an air vent hole similar to the conventional one may be provided.

According to the present invention, as described above, a shaft member is disposed in the center of the float chamber and passes through the float in the vertical direction to allow vertical movement of the float disposed in the float chamber. extending along its longitudinal axis and having a lower end open near the bottom of the float chamber at the side of the shaft member, and an upper end communicating with the outside of the float chamber to a fuel nozzle provided in the carburetor body. By forming a fuel guide passage that opens to the bottom, the vicinity of the center bottom of the float chamber 14 and the nozzle can be connected through the shortest distance, thereby ensuring that the fuel in the float chamber is supplied regardless of the inclination of the carburetor. Moreover, it can be quickly supplied to the internal combustion engine, and the operational response of the engine can be improved and its operation can be maintained properly.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a float device according to the present invention, and FIG. 2 is a sectional view taken along line 2--2 shown in FIG. 12: Carburetor, 14: Float chamber, 18: Float, 20: Valve member, 24: Fuel inlet, 28:
Fuel level, 48: shaft member, 52: fuel guide passage, 54: air vent passage.

Claims (1)

[Scope of utility model registration request] A float device in which a float is provided in the float chamber for operating a valve member in response to changes in the fuel liquid level in the float chamber to open and close a fuel inlet into the float chamber provided at the lower part of the carburetor main body. A shaft member is disposed in the center of the float chamber and extends vertically through the float to allow the float to move up and down. A fuel guide passage is formed at a side of the shaft member to open near the bottom of the float chamber, and whose upper end opens to the outside of the float chamber to communicate with a fuel nozzle provided in the carburetor body, and An air vent passage is formed in the shaft member in parallel with the fuel guide passage, one end of the air vent passage is open to the upper part of the float chamber near the upper end of the shaft member, and the other end is formed in the shaft member. A float device for a vaporizer that opens to the atmosphere at the lower end of the