JPH0156262B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a float valve device for a carburetor of an internal combustion engine.

[Prior Art] In a float type carburetor, when the fuel reaches the reference oil level, the float pushes the valve body against the fuel inlet, suppresses excess fuel from flowing into the float chamber, and keeps the float chamber always positioned. Hold fuel. However, so that the inflow valve is completely closed due to the position of the fuel,
A large float is required to provide a large closing force to the inlet valve.

The applicant is Japanese Patent Application No. 59-2646.
(Refer to Publication No. 11553), they applied a toggle mechanism to amplify the buoyancy of the float and transmit it to the inflow valve. According to the float valve device for a carburetor according to this application, a large valve closing force is applied to the inflow valve with a small float, and stable operation of the inflow valve against vibrations of the engine can be obtained. However, this is not preferable because the direction of action of the valve closing force is inclined with respect to the central axis (movement direction) of the inflow valve.

[Problems to be Solved by the Invention] The object of the present invention is to provide a carburetor whose performance is improved by applying the valve-closing force from the float to the inflow valve coaxially at the position where the inflow valve engages with the valve seat. An object of the present invention is to provide a float valve device.

[Means for Solving the Problem] In order to achieve the above object, the present invention has a conical shape connected to the fuel inlet deep inside the horizontal valve chamber formed on one side wall of the housing housing the float. A valve seat is formed, the base end of the lever is tiltably supported by a support shaft on the side wall of the housing opposite to the valve chamber, the tip of the lever is brought into contact with a float, and the lever is housed in the middle part of the lever and the valve chamber. The lever is connected to the inflow valve by a link, and the supporting shaft of the lever is disposed above the inflow valve so that the link becomes horizontal at the position where the inflow valve engages with the valve seat.

[Function] The lever 9 is supported by the support shaft 10 so as to be pushed up by the float 8 above the inflow valve 5 on the opposite side wall of the housing 1 to the inflow valve 5.
The link 15 connecting the intermediate portion of the lever 9 and the inflow valve 5 is horizontal in the closed state when the inflow valve 5 engages with the valve seat 7, so the link 15 is applied from the float 8 via the lever 9 to the link 15. The valve closing force is applied to the inflow valve 5
is transmitted in the direction of the central axis. The attitude of the inflow valve 5 is very stable, and the inflow valve 5 moves parallel to the conical valve seat 7 without tilting, so that the inflow valve 5 is smoothly engaged with the center of the valve seat 7, and the fuel inlet 4 is completely closed. Even if the carburetor is subjected to vibrations, the valve remains stably closed.

[Embodiments of the Invention] As shown in FIG. 1, a float chamber for accommodating a float 8 is formed inside a housing 1 coupled to the bottom of a carburetor body 2 having an intake passage (not shown). The float chamber is opened to the atmosphere via an air passage 3 formed in the carburetor body 2. A horizontal cylindrical valve chamber 6 is formed in one side wall of the housing 1, and a conical valve seat 7 is formed deep inside the valve chamber 6. Valve seat 7 communicates with fuel inlet 4 .

The valve chamber 6 of the housing 1 and the valve chamber 6 of the opposite side wall
The proximal end of the lever 9 is tiltably supported by a support shaft 10 at a portion higher than that (in the illustrated embodiment, higher by a height s). The tip of the lever 9 is bent slightly upward and comes into contact with the center of the upper surface of the float 8. A link 15 is connected to the intermediate portion of the lever 9 and the inflow valve 5. The inflow valve 5 movably fitted into the valve chamber 6 has a triangular or quadrangular cross section, has a fuel passage formed between it and the inner peripheral surface of the cylindrical valve chamber 6, and has a valve seat at its tip. A conical portion engageable with 7 is formed.

An important feature of the present invention is that when the inflow valve 5 is in the closed state engaged with the conical valve seat 7, the link 15 is horizontal, that is, the link 15 and the central axis of the inflow valve 5 are aligned. The position of the support shaft 10 of the lever 9 is set in advance so that it is aligned in a straight line when viewed from the side.

As shown in FIG. 2, the lever 9 is actually a plate-shaped member made of synthetic resin, and the tip end 12 is bifurcated. A support shaft 10 is inserted through a cylindrical portion 11 at the base end of the lever 9, and both ends of the support shaft 10 are fixed to the wall of the housing 1. A cylindrical portion 13 parallel to the cylindrical portion 11 is formed at the intermediate portion of the lever 9. The link 15 is made by bending both ends of the wire at right angles to form the shaft part 1.
5a and 15b are formed. The shaft portion 15a is inserted into the cylindrical portion 13 of the lever 9, and the shaft portion 15b is inserted into the horizontal hole 14 provided at the base end of the inflow valve 5.

Next, the operation of the float valve device for a carburetor according to the present invention will be explained. When the fuel in the float chamber of the housing 1 is at a specified oil level H, the lever 9 is pushed up by the float 8 using the support shaft 10 as a fulcrum, and the inflow valve 5 is pushed to the right by the link 15.
The conical tip of the inflow valve 5 is engaged with the conical valve seat 7, and the fuel inlet 4 is closed. When the tip 12 of the lever 9 is pushed up, the link 15 is aligned horizontally, that is, parallel to the central axis of the inflow valve 5, so that the inflow valve 5 does not tilt in the valve chamber 6 and moves toward the center of the conical valve seat 7. Smoothly engaged. Even if the carburetor is subjected to vertical vibrations, the inflow valve 5 is maintained horizontally within the valve chamber 6 by the link 15, so that a stable closed state is maintained.

The fuel in the float chamber is sucked into the intake passage of the carburetor main body 2 through a fuel passage (not shown). When the float 8 descends as the fuel oil level decreases, the lever 9 rotates clockwise around the support shaft 10.
Link 15 moves to the left. Therefore, the inflow valve 5 is separated from the valve seat 7 by the link 15,
Fuel inlet 4 opens. Fuel in the fuel tank is replenished into the housing 1 through the fuel inlet 4 and the valve chamber 6 by a fuel pump (not shown).

When the fuel oil level rises, the lever 9 rotates counterclockwise about the support shaft 10, the link 15 moves to the right, and the inflow valve 5 is pressed against the valve seat 7. When the inflow valve 5 engages with the valve seat 7, the link 15 becomes horizontal and is aligned with the central axis of the inflow valve 5, so that the direction of action of the valve closing force of the link 15 and the direction of movement of the inflow valve 5 coincide. In this way, the fuel in the housing 1 is always maintained at approximately the specified oil level.

[Effects of the Invention] As described above, the present invention forms a conical valve seat connected to the fuel inlet deep inside the horizontal valve chamber formed on one side wall of the housing that accommodates the float. The base end of the lever is tiltably supported by a support shaft on the side wall opposite to the chamber, the tip of the lever is in contact with a float, and the intermediate part of the lever and the inflow valve housed in the valve chamber are connected by a link to prevent inflow. The lever's spindle is placed above the inflow valve so that the link is horizontal at the position where the valve engages the valve seat, so the force transmitted from the float to the link is increased by the lever. In addition, in the closed state where the inflow valve engages with the valve seat, the link connecting the lever and the inflow valve is in a horizontal state, and the direction of the force that the link pushes against the inflow valve is aligned with the central axis of the inflow valve. Since they match, the posture of the inflow valve in the valve chamber is very stable, the operation is smooth, and a stable valve closed state can be obtained against vibrations of the carburetor.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a float valve device for a carburetor according to the present invention, and FIG. 2 is a plan sectional view taken along the first line AA. 1: Housing, 4: Fuel inlet, 5: Inflow valve,
6: Valve seat, 8: Float, 9: Lever, 12: Tip, 15: Link.

Claims (1)

[Claims] 1. A conical valve seat connected to the fuel inlet is formed deep inside a horizontal valve chamber formed on one side wall of the housing that accommodates the float, and the base end of the lever is placed on the opposite side wall of the housing from the valve chamber. The lever is tiltably supported by a support shaft, the tip of the lever touches the float, the middle part of the lever and the inflow valve housed in the valve chamber are connected by a link, and the link is made at the position where the inflow valve engages with the valve seat. A float valve device for a carburetor, characterized in that the lever shaft is located above the inflow valve so that the valve is horizontal.