JPH01280671A - Vaporized gasoline control device for carburetor - Google Patents

Abstract

PURPOSE:To perform simple and proper control of discharge of steam gasoline, by a method wherein a spring formed by a shape memory alloy is used for the working of a valve body movably situated between opening parts on the inner vent side and the canister side of a discharge passage for vaporized gasoline. CONSTITUTION:A fuel level in a float chamber 1 is held at a normally specified value by means of a float 2. A pipe 3 for an inner vent has the one end 4 opened on the upper stream side of a suction pipe 5 and the other end opened to a gas chamber 7 on a fuel oil level. In this case, when, during running of an internal combustion engine, the temperature of the interior of a float chamber 1 is increased along with the increase in a temperature in an engine room, a spring 8 formed by a shape memory alloy is worked in a direction, in which it is shortened, at a set temperature to decrease a spring force. Thereby, a valve body 6 is energized through the force of a balance spring 16 and is seated to an opening part 14 of the pipe 3 for an inner vent to open an opening part 9 on the canister side. As a result, steam gasoline generated in the float chamber 1 is guided out to a canister passage 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a mechanism for controlling evaporated gasoline generated from a vaporizer float chamber, and particularly to a evaporated gasoline control device with a reliable and simple structure.

[Conventional technology]

In conventional devices, when the key switch is turned on, the solenoid valve is turned on, closing the opening on the canister side and when the engine is stopped, the solenoid valve is turned off and the canister side is opened. According to this, when the float chamber is at a high temperature such as during high-speed operation during idling, evaporated gasoline is released into the atmosphere through the inner vent, which is a problem that occurs regardless of the temperature inside the float chamber. Related devices of this type include Utility Model Publication No. 61-1.4608.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into consideration the simplification of the structure, and there is a problem in making the carburetor more compact.

Further, control using a solenoid valve is performed regardless of the temperature inside the float chamber, and is insufficient as a control device for evaporated gasoline.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a vaporized gasoline control device for a vaporizer that is simple in structure and reliable.

[Means to solve the problem]

The above object is achieved by operating the valve body for controlling evaporation gas using a shape memory alloy whose shape changes based on temperature detection.

[Effect]

The evaporated gasoline control valve body uses the spring force of a shape memory alloy spring to close the opening on the canister side when the temperature is low and there is little evaporated gasoline, and when the engine is stopped after high-speed operation or when the engine is at high temperature during idling. When flow 1 - room temperature - H, the valve body is operated by a shape memory alloy whose shape is memorized at a certain temperature to open the canister side.

According to the present invention, the flow is maintained regardless of whether the engine is ON or OFF.
1 - It is possible to reliably capture the room temperature and perform control operations.

Moreover, an actuating device such as a solenoid valve diaphragm is not required, and the control actuating device can be built into the float chamber, resulting in a small, simple structure, and highly reliable vaporized gasoline control device.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a conventional technique in which evaporated gasoline is controlled using a solenoid valve.

The curved surface of the fuel inside the float chamber 1 is always kept constant by the 77 piece 2. 3 is a pipe for inner vent 1~, one end of which is 4
opens upstream of the intake pipe 5, and the other end opens into the air chamber 7 above the oil level. The passage 9 has one end 11 communicating with a charcoal canister or the like (not shown), and the other end communicating with an airtight 7 similar to the inner hem 1 to the vibe 3.

Next, the operation will be explained.

When the engine is stopped, no current flows through the solenoid valve 13 and the valve body 6 closes the inner vent opening 14 and opens the canister side opening 10 due to the force of the spring 15, and the evaporation generated in the float chamber 1 is removed. Gasoline is led to the canister via passage 9. When the engine is operated, a current flows through the electromagnetic valve 13 and the valve body 6 overcomes the spring 5 due to electromagnetic force to close the side port 14 to the inner vent 1.

Next, an embodiment of the present invention is shown in FIG. 2 and a detailed view of part P. This is explained by:

First, the structure will be explained.

The basic passage configuration is the same as the conventional technology product, but the valve body 6
is not connected to the electromagnetic button t, but is fixed by a shape memory alloy spring 8 between the canister side opening 9 and the air chamber 7 communicating with the pipe 3 to the inner vent 1.・Next, the operation will be explained.

When the internal temperature of the float chamber is low, such as when the engine is stopped, the canister side part 1'' is closed by the spring force of the shape memory alloy spring 8.

Next, when the temperature inside the float chamber rises due to the rise in temperature in the engine room and during operation, the spring 8, whose shape has been memorized at a constant temperature, works in the direction of becoming shorter at cent temperature, causing the spring force to weaken. When the temperature inside the float chamber 1 decreases, the spring 8
The valve body 6 overcomes the balance spring 15 and presses the valve body 6 toward the canister opening 9 side.

〔Effect of the invention〕

According to the present invention, evaporated gasoline is reliably controlled by the temperature inside the float chamber, and parts such as a solenoid valve and diaphragm are not required, so that an evaporated gasoline control device with reliable operation and simple structure can be obtained. , reliability and small size of the vaporizer.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the prior art, FIG. 2 is a sectional view showing an embodiment of the present invention, and FIG. 3 is an enlarged view of part P.

Claims (1)

[Claims] 1. A vaporized gasoline discharge passage is provided in the air chamber of the carburetor float chamber, and the passage is provided with a passage to the inner vent side and a passage to the canister side facing each other, and a passage is provided between the opening on the inner vent side and the opening on the canister side. In a vaporized gasoline control device for a vaporizer, in which the valve element moves in the axial direction to alternately close the openings, the valve element has a shape that changes depending on a certain temperature when the valve element is operated. A vaporized gasoline control device for a vaporizer characterized by using a memory alloy spring.