JPS6243059B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a float device for maintaining a constant fuel level in a float chamber of a carburetor. Conventionally, a synthetic resin molded product in which a floating body and a control arm for opening and closing a fuel inlet valve in a float chamber are integrally molded is used as a float for a carburetor. Since such floats undergo some dimensional changes due to temperature changes or immersion in fuel, it is common practice to set the dimensions in consideration of dimensional changes at the time of design. By the way, the composition of gasoline used as a fuel differs depending on the product and the country of production, so even if the above-mentioned dimensional changes are taken into consideration, errors are likely to occur and the operation may become unstable. Moreover, in recent years, in order to save on gasoline, it has been considered to use fuel in which about 20% alcohol is mixed into gasoline, so-called gas holes, and it is thought that the above-mentioned problems will become even more pronounced.

From this point of view, an object of the present invention is to improve the part that is likely to cause malfunction when the synthetic resin float undergoes dimensional changes, that is, the pin insertion hole for pivotally supporting the control arm on the vessel frame. It is something to do.

The present invention will be explained below with reference to illustrated embodiments. In the figure, 1 indicates a float type vaporizer. vaporizer 1
The intake body 2 is formed by die-casting a light alloy, and a saucer 3 is removably fixed to the lower surface of the intake body 2, and a float chamber 4 is formed inside the intake body 2.
Reference numeral 5 denotes a fuel inflow passage, to the upper end of which a fuel pipe (not shown) is connected, and to the lower end a fuel inflow valve 6 is formed. The inflow valve 6 is composed of a valve port 6a formed at the lower end of the inflow path 5 and a valve body 6b seated on the valve port.The valve body 6b opens the valve port 6a by gravity and is opened by a float 7 to be described later. It is then lifted upward and operated to close the valve port 6a. The float 7 consists of a control arm 7a and a floating body 7b.
It is pivotably supported by a pin 9 between the protrusions 8, 8. And those 7a and 7b are synthetic resin,
For example, it is integrally molded from polypropylene. The above configuration is not significantly different from conventionally known carburetors.

An insertion hole 11 for the pin 9 is provided at the base end of the control arm 7a, and the width thereof is made smaller than the dimension between the protrusions 8, 8, so that it will not come into contact with the protrusions 8, 8 even if it expands due to being immersed in fuel. There is no. Further, a collar 12 made of metal, for example brass, is press-fitted into the pin insertion hole 11 and fixed thereto. The collar 12 has an inner diameter slightly larger than that of the pin 9, and is machined to be slightly shorter than the dimensions of the protrusions 8, 8. 13 is an air vent.

In the above configuration, when fuel is supplied to the inflow passage 5, if the liquid level in the float chamber 4 is low, the float 7 is lowered and the inflow valve 6 is opened, and the float chamber 4 is
Introduce fuel into the tank. When the float 7 rises accordingly and the fuel level reaches a predetermined height, the inflow valve 6 is closed to cut off the inflow of fuel. Thus, while the engine is operating, the liquid level in the float chamber 4 is constantly adjusted to a predetermined level.

As explained above, this invention provides a vaporizer in which a floating body and a control arm are integrally formed of synthetic resin, in which the pin hole formed in the control arm is formed to have a larger diameter than the outer diameter of the pin. A metal collar is then press-fitted into the float, and a pin is inserted through the collar to pivot the float to the intake cylinder, so there is a risk that it will immerse in gasoline or other fuel in the float chamber and swell. Also, the protrusion that supports the pin is formed integrally with the metal intake cylinder, and a metal collar is press-fitted into the pin insertion hole of the control arm, so the size of the gap between the pin and the collar varies. There is no. Therefore, since there is no need to provide an excessively large gap between the two in advance to account for the amount of deformation, the operation of the fuel inlet valve can be maintained with high precision. Additionally, since the axial movement of the control arm is restricted by the collar, the size of the space between the protrusions that support it can be significantly reduced compared to when this function is provided to the control arm itself. It becomes possible. Therefore, even if the control arm swells, it will not touch the protrusions and cause unstable operation. Furthermore, the float can be manufactured using the same method as conventional methods, except for the collar, which is molded from synthetic resin, and the increase in manufacturing costs can be kept to a minimum. Even when gasoline fuel or fuel containing alcohol is used, it has an effect that does not cause any inconvenience.

[Brief explanation of the drawing]

The drawings show an example of the embodiment of the present invention, and FIG. 1 is a sectional view of a carburetor, and FIG. 2 is a sectional view thereof. 4...Float chamber, 6...Fuel inflow valve, 7...
Float, 9...pin, 12...color.

Claims (1)

[Claims] 1 A float consisting of a floating body and a control arm protruding from the floating body is integrally formed of synthetic resin, and this float is swingably connected to the lower surface of the intake cylinder with a pin inserted through the control arm, and the Therefore, in a carburetor configured to open and close a fuel inlet valve, a metal collar is press-fitted into the base end of the control arm, and a pin is inserted through this collar to be pivotally supported on the intake cylinder. The base end of the control arm is supported between two protrusions cast integrally with the intake cylinder, and the length of the metal collar is approximately equal to the dimension between the protrusions. A float device for a vaporizer whose end is slightly narrower than the metal collar.