JPH0139885Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a sliding throttle valve type carburetor that has a stable air-fuel ratio during idling and low speeds and does not cause exhaust gas pollution. The present invention relates to a sliding throttle valve type carburetor having a sliding throttle valve type.

Conventional sliding throttle valve carburetor (e.g.
It is disclosed in Publication No. 12606. ),
A sliding throttle valve carburetor has been proposed in which a synthetic resin coating is formed on the outer periphery of a cylindrical sliding throttle valve. In this case, since the sliding part between the carburetor body and the sliding throttle valve becomes a circular sliding surface, it is difficult to attach the sealing member, and the cylindricity of the circular sealing member and the cylindrical shape of the carburetor body It is difficult to accurately form the cylindricity of the shaped sliding surface, and it is not possible to ensure sufficient sealing performance of the sealing member. Therefore, when the engine is idling or operating at low speed when the throttle valve is fully closed, intake air may flow into the engine through the cylindrical sliding surface, making the air-fuel ratio between air and fuel unstable and causing exhaust gas pollution. There was a drawback.

The present invention was developed in view of these conventional drawbacks, and its purpose is to stabilize the air-fuel ratio characteristics during engine idling and low-speed operation when the sliding throttle valve is fully closed, and to eliminate exhaust gas pollution. An object of the present invention is to provide a sliding throttle valve type carburetor that can be used.

One embodiment of the present invention will be described with reference to FIGS. 1 to 3. A float 8 is used to connect a fuel port 3 that injects fuel into an intake passage 2 that passes through the carburetor body 1 and communicates with the engine. Fuel is supplied from the fuel chamber 9 where the oil level is maintained. A sliding throttle valve 4, which is a plate-like member that controls opening and closing of the intake passage near the fuel port 3, is fitted into a sliding groove 5 provided in the carburetor body so that it can slide up and down with respect to the carburetor body. The sliding throttle valve has a flat sliding surface 6.
is located. The sliding throttle valve is provided with a semi-cylindrical ventilary formation 10 in which a needle 11 is inserted into the fuel port 3.
A wire 12 operated by a throttle (not shown) is fixed. A spring 13 is installed between the lid 14 and the sliding throttle valve, and presses the sliding throttle valve downward.

The sliding throttle valve is attached in an inverted U-shape to the flat sliding surface on the engine side, and slides together with the sliding throttle valve, and as it moves upward, it surrounds the intake passage. A synthetic resin hollow pipe member 7 is attached so as to be open. The synthetic resin hollow pipe member 7 includes a resin containing a filler of tetrafluoroethylene resin or difluoridated molybdenum, a metal O-ring, and synthetic rubber. Alternatively, a synthetic resin coating may be formed on the flat sliding surface of the sliding throttle valve without attaching a sealing member.

To explain how it works, when the sliding throttle valve is close to fully closed and the engine is idling or operating at low speed, when air flowing in from the direction shown by the arrow tries to pass through the sliding part of the sliding throttle valve, it forms an inverted U-shape. It is sealed with a synthetic resin hollow pipe member to prevent passage. In addition, when the sliding throttle valve moves up and down, it slides with the sliding throttle valve and is a sealing member installed in an inverted U shape, so there is no sealing member installed on the lower side, so the intake air Damage caused by sliding between the channel opening end and the sealing member is prevented. In addition, since the sealing member is placed on the flat sliding surface of the sliding throttle valve on the engine side,
The sealing surface is brought into close contact with the fluid force caused by the intake air flowing in the direction of the arrow, improving sealing performance.

The sliding throttle valve is provided with a flat sliding surface, and a sealing member that slides together with the sliding throttle valve and has airtightness is disposed on the flat sliding surface. Compared to forming a synthetic resin coating on the outer periphery of the dynamic throttle valve, it is easier to improve the processing accuracy, and the flatness of the sliding groove 5 of the carburetor body is improved.
It is only necessary to control the flatness of the flat sliding surface of the sliding throttle valve. Furthermore, since the sliding throttle valve is shaped like a flat plate rather than a cylinder, the air is rapidly squeezed and a large amount of gasoline is sucked out, resulting in a significant improvement in response, especially in the medium and low speed range. be.

As described above in detail, the present invention has a main body 1 of a vaporizer.
The carburetor body is equipped with an intake passage 2 that passes through the interior and communicates with the engine, and a fuel port 3 that injects fuel into the intake passage, and a sliding throttle valve 4 that controls opening and closing of the intake passage near the fuel opening. In a sliding throttle valve type carburetor that is slidably arranged on the carburetor body, the sliding throttle valve is mounted in an inverted U shape on the flat sliding surface 6 of the sliding throttle valve that comes into contact with the sliding groove 5 provided in the carburetor body. , sliding with the sliding throttle valve;
In addition, the air-tight sealing member is arranged to surround or open the intake passage with the upward movement, so that the air-fuel ratio characteristics are stabilized when the sliding throttle valve is fully closed, the engine is idling, and the engine is running at low speeds. , it was possible to provide a sliding throttle valve type carburetor that can eliminate exhaust gas pollution.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the sliding throttle valve type carburetor of the present invention, FIG. 2 is a partial sectional view taken along line A-A in FIG. 1, and FIG. It is a front view of the sliding throttle valve seen from BB of FIG. 1... Carburetor body, 2... Intake path, 3... Fuel port, 4... Sliding throttle valve, 5... Sliding groove, 6... Flat sliding surface, 7... Synthetic resin hollow pipe parts.

Claims (1)

[Claims for Utility Model Registration] (1) An intake passage 2 that penetrates the inside of the carburetor body 1 and communicates with the engine, and a fuel port 3 that injects fuel into the intake passage, In a sliding throttle valve type carburetor in which a sliding throttle valve 4 for controlling opening and closing of the intake passage is slidably disposed on the carburetor body, a flat plate of the sliding throttle valve comes into contact with a sliding groove 5 provided in the carburetor body. an airtight seal attached to the sliding surface 6 in an inverted U shape, sliding together with the sliding throttle valve, and surrounding or opening the intake passage as the sliding throttle valve moves upward; A sliding throttle valve type carburetor made up of arranged parts. (2) The sliding throttle valve type carburetor according to claim 1, wherein the sealing member is a hollow pipe member 7 made of synthetic resin. (3) The sliding throttle valve type carburetor according to claim 1, wherein the sealing member is a synthetic resin film formed on the flat sliding surface of the sliding throttle valve. (4) The sliding throttle valve type carburetor according to claim 1, wherein the sealing member is arranged on a flat sliding surface of the sliding throttle valve on the engine side. (5) The sliding throttle valve type carburetor according to claim 1, wherein the sliding throttle valve is made of a plate-like member.