JPS6135723Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a check valve device for an accelerator pump.

In the conventional acceleration fuel system, as shown in FIG. 1, when the acceleration pump is not operating, the engine's intake negative pressure acts into the pump chamber 1 through the acceleration fuel nozzle 2 to prevent fuel from being sucked out. Therefore, a check valve 4 is installed on the fuel passage 3 leading from the pump chamber 1 of the acceleration pump A to the acceleration fuel nozzle 2. It is always biased in the direction of closing the fuel passage 3. Therefore, when the acceleration pump A is operated, the spring 5 acts as a resistance, resulting in a large operating load, resulting in a decrease in the discharge amount of the acceleration fuel and a delay in the injection of the acceleration fuel.

If the spring 5 is changed to a weaker one in order to solve the above drawback, the check valve 4 will open due to the engine's intake negative pressure even when the accelerator pump A is not operating, sucking out fuel from the accelerator pump, resulting in engine malfunction. .

The purpose of the present invention is to eliminate the above-mentioned drawbacks. A hole 8 is provided in the valve seat surface 7 of the check valve 4a, and the upper end opening 3b is located in the center of the hole 8 on the same plane as the valve seat surface 7. A protruding cylinder 4'a is provided upright to form a gap between the hole 8 and the inner circumferential surface of the notch 8, and connects the hole 8 to the pump chamber 1 of the acceleration pump. The base end side of a is connected to the accelerating fuel nozzle 2.

According to the above configuration, when the acceleration pump A is activated in response to the opening operation of the throttle valve, the pressurized fuel is ejected from the gap 3a between the protruding cylinder 4'a and the inner peripheral surface of the hole 8, The discharge pressure is applied to a wide area of the check valve 4a to push up the check valve 4a and open the opening 3b. When the opening 3b opens, the pressurized fuel flows into the protruding tube 4'a, and is injected into the intake passage 6 from the accelerating fuel nozzle 2.

In this way, since the outflow side opening 3a is provided around the inflow side opening 3b, when the acceleration pump A is operated, the discharge valve acts on a wide area of the check valve 4a.
The check valve 4a can be opened reliably.

In addition, according to the present invention, since the check valve does not require a spring like the conventional one, there is no large resistance when the accelerator pump operates, and fuel for acceleration is quickly supplied, improving the performance of the accelerator pump. It can be done, and its practical value is great.

In addition, the accelerating fuel nozzle was generally installed in the air intake passage on the side of the air cleaner from the throttle valve of the carburetor, but by using the check valve device of the present invention, the accelerating fuel nozzle can be installed closer to the throttle valve than the throttle valve of the carburetor. It can be installed in the intake passage on the engine side, and accelerating fuel can be quickly supplied to the engine.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing the acceleration system of a conventional carburetor, FIG. 2 is a first embodiment of the acceleration system of the carburetor of the present invention, and A is a sectional view showing the entire carburetor of the present invention.
B is a cross-sectional view showing the main part of the present invention, C is a plan view, and FIG. 3 is a cross-sectional view showing a second embodiment of the main part of the acceleration system of the carburetor of the present invention. A...acceleration pump, 1...pump chamber, 2...acceleration fuel nozzle, 3...fuel passage, 4a...check valve, 7...valve seat surface, 8...hole.

Claims (1)

[Scope of utility model registration request] A hole is provided in the valve seat surface of the check valve, and a protruding cylinder is erected in the center of the hole so that the upper end opening is located on the same plane as the valve seat surface and a gap is formed between the hole and the inner peripheral surface of the hole. A check valve device for an acceleration pump, characterized in that the hole is connected to a pump chamber of the acceleration pump, and the proximal end side of the protruding cylinder is connected to an acceleration fuel nozzle.