JPS61106956A - Manual choke carburetor - Google Patents

Abstract

PURPOSE:To surely perform starting operation, by providing a stopper, longitudinally moved in accordance with a temperature, oppositely facing to the lever of a manual choke valve. CONSTITUTION:When an engine is started, a carburetor 1 closes a choke valve 2, provided in the upstream of a throttle valve 4, by pulling a wire 8 to turn a lever 9 of the choke valve 2. A protrusive part 9a of the lever 9 is adapted to a stopper 16 in a lever 14 providing a return spring 15, and an opening of the choke valve is restricted. The carburetor arranges within a turning range of the lever 14 a piston 21 longitudinally moved by was extending and contracting in accordance with a peripheral temperature of the engine. The piston 21 retreats to a position fully closing the choke valve when the engine is at a low temperature while protrudes to a position opening the choke valve when the engine is at a high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a manual choke carburetor for supplying air-fuel mixture to a gasoline engine. It concerns a choke vaporizer.

The carburetor is used to limit the amount of intake air when starting the engine.
Manually operate the choke valve.

It is well known to open and close the valve either semi-automatically or automatically, with the choke valve closed when the temperature is cold and the choke valve opened as the temperature rises.

By the way, in carburetors for general-purpose engines equipped with a manual choke mechanism in which the choke valve is closed by pulling a choke wire connected to a choke lever fixed to the choke valve shaft, there is a special starting function in addition to the choke valve. Since there is no auxiliary device and the throttle valve and choke valve must be operated completely separately for starting and warming up, it is necessary to operate according to a predetermined sequence and a high degree of skill is required. Ru. Especially when starting, pull the choke wire and close the choke valve.
After the valve is closed, the driver must open the 11-' valve appropriately.
It is common to perform choke operations according to this order.

Therefore, even though there is no need to operate the choke when I is open, the choke wire is often pulled to start the engine, and for this reason fuel is sucked into the suction pipe unnecessarily, resulting in poor starting. The problem was that repeated attempts to start the engine by pulling the choke wire caused fuel to be sucked into the intake pipe each time, making it impossible to start.

Particularly in the case of small boat engines (outboard motors), if the engine cannot be started at sea, human life may be at risk. As a countermeasure, an air hole is installed in the choke valve to prevent the mixture from becoming too rich even when the valve is closed when the valve is warm, but there is a concern that it will impair starting performance when the valve is cold. It is difficult to provide air holes of appropriate size.

The present invention solves these problems and automatically adjusts the closing position of the choke valve according to the temperature even if the choke wire is pulled during startup.

Therefore, it is an object of the present invention to provide a manual choke carburetor that can ensure starting and subsequent engine rotation in both cold and warm conditions.

The present invention includes a rotatable lever provided with a stopper that regulates the closed position of the choke valve, and a temperature compensator having a piston and a temperature-sensitive material that contacts the lever.

The piston has a structure in which the position of the stopper is changed by rotating the reno (-) as the temperature changes. □ Embodiment An embodiment of the present invention is shown in the drawings. I will explain based on =.

Choke valve 2. A float chamber 6 is provided below a main body 5 having an intake passage 1 extending in the horizontal direction, in which a venturi 3 and a throttle valve 4 are arranged in this order.

A choke lever 9 to which a choke wire 8 is connected is fixed to the choke valve shaft 7, and a throttle lever 12 to which an accelerator wire 11 is connected is fixed to the throttle valve shaft 10, and the choke valve 2 and throttle valve 4 are They do not have mechanical interlocking means and operate independently of each other through separate opening and closing operations.

A support shaft 13 is fixedly protruded above the choke valve shaft 7 and parallel to the choke valve shaft 7 on the upper part of the main body 5, and a lever 14 is rotatably supported on this support shaft 13. Spring 15 is attached.

One end of the return spring 15 engages with the lever 14 to apply a rotational force in one direction. The lever 14 is formed in a U-shape, and its legs 14a and 14b at both ends are attached to the support shaft 13 to be stably supported, and a pin-shaped stop collar 16 is protruded from an extension of one leg 14a. There is. This stopper 16 is adapted to come into contact with the protrusion 9a of the choke lever 9.

A temperature compensator 17 is attached to the side of the main body 5 and extends in a direction parallel to the intake path l. This temperature compensator 17 has a support cylinder 22 in which a piston 21 is fitted, fixedly protruding from the open end side of a housing 20 which encloses a temperature sensitive material i1g made of thermowax and is closed with an elastic film 19 at the open end. configured 2
A support tube 22 is attached to a mounting flange 24 protruding from the side of the main body 5.
It is attached to the main body 5 so that its position can be adjusted by threading it with a screw 23 on the outer peripheral surface and fixing it in a predetermined position with a locking nut 25. Further, the tip end surface of the piston 21 is bent so as to be in contact with the lever 14 between the support shaft 13 and the stopper 16.

In this embodiment configured in this way, when the temperature-sensitive substance 18 is assimilated and contracted when it is cold, the piston 21 is pushed into the support tube 22 by the lever 14 which rotates by the elastic force of the return spring 15, and therefore the piston 21 is pushed into the support tube 22. 16 moves the choke lever 8 to a position where it can be rotated until the choke valve 2 is fully closed (
(See Figure 1), as the temperature rises, the temperature-sensitive substance 18
becomes a fluid state and expands, pushing out the piston 21 in contact with the proximal end of the elastic membrane ILIC from the support cylinder 22, rotating the lever 14, and moving the position of the stopper 16. Therefore, when the choke wire 8 is pulled to close the choke valve 2 when starting the engine, the choke lever 9 hits the stopper 16 to prevent further closing of the valve. The engine will now be started (see Figure 3).

Here, by appropriately selecting the temperature characteristics of the temperature-sensitive substance 18 and the ratio of the displacement of the stopper 16 to the stroke of the piston 21, the i position of the stopper 16 can be set to be thicker than the stroke of the piston 21 (and a small temperature compensation choke valve 2 depending on the temperature.
The valve closing position can be adjusted as desired.

For example, when the ambient temperature is about 10° C. or lower, the choke valve 2 can be fully closed, and at about 40° C., the choke valve 2 can be adjusted to a closed position about 25 degrees from the fully closed position.

Therefore, it is possible to automatically create a valve closing position that guarantees an appropriate tC intake air amount depending on the temperature.

According to the present invention, the position of the stopper that regulates the closing position of the choke valve is changed by the temperature compensator in accordance with temperature changes. Even if the engine is pulled, the choke valve can be set to the closed position according to the temperature. This eliminates starting failures and ensures reliable starting without over-enriching the air-fuel mixture even when the engine is warm. By opening appropriately, engine rotation can be maintained stably.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention when it is cold;
FIG. 2 is a side view, FIG. 3 is a front view at warm temperature, and FIG. 4 is a longitudinal sectional view of the temperature compensator. 2...Choke valve, 4...Choke valve, 5
...Body, 7...Choke valve shaft, 9.
..... Choke rack A -, 14 ..... lever, 15 .... return spring, 16 ..... stopper, 17 ..... temperature compensator, IB...Temperature-sensitive substance, 21...Piston. ] with one continuation li tE tj,j (/':j-Ti(
) March 27, 1985 [1 Showa 59 (T Special revision application 227079.2 Name of the invention Manual choke carburetor 3 Relationship with the person making the amendment A'1 Patent applicant 11 Tokyo Parts Co., Ltd. 5 guns [11ffi12Q
Name (Name) Co., Ltd. '41 Nippon Vaporizer Manufacturing Co., Ltd. 4
Agent (〒10/I) 11 Locations 3 T Kyobashi, Chuo, Tokyo [No. 15 March (Takegashi Building) 5 Supplement 1 Order Roy 1 Sent on February 26, 1985 6 Drawings subject to amendment 7 Amendment Amend the content drawing as shown in the attached sheet.

Claims (4)

[Claims] (1) A rotatable lever provided with a stopper that regulates the closed position of a choke valve, a piston in contact with the lever, and a temperature compensator having a temperature-sensitive substance, the piston changing as the temperature changes. A manual choke carburetor, characterized in that the lever is rotated to change the position of the stopper. (2) The manual chalk vaporizer according to claim (1), wherein the temperature-sensitive substance is thermowax. (3) The manual choke carburetor according to claim (1), wherein the lever and the temperature compensator are associated with each other such that the displacement of the stopper is greater than the stroke of the piston. (4) The manual choke carburetor according to claim (1), in which the choke valve and the throttle valve are not mechanically interlocked.