JPH0669544U - Flow control valve - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the valve from sticking with adhesive components and not opening. [Structure] The inflow port 12 is connected to the upper part of a fuel tank of an automobile, and the exhaust port 13 is connected to a canister. Electromagnetic solenoid 2
When the fuel vapor pressure applied to the pressure chamber 20 is equal to or higher than the set pressure in the normal state where the fuel cell 1 is not energized, the rubber valve body 16 moves upward against the spring 19 and separates from the valve seat 14 to evaporate fuel vapor. Control the flow rate of. Solenoid valve 21 at the time of diagnostic check
When the current is applied to the plunger 24, the plunger 24 is attracted to the stator 22 and rises together with the rod 25. The upper end of the rod 25 pushes the valve element 16 upward to forcibly open the valve and release the valve sticking.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a flow control valve.

[0002]

[Prior art]

 In an automobile, as shown in FIG. 5, a canister 2 having a built-in activated carbon (adsorbent) that adsorbs evaporated fuel (evaporation) from a fuel tank 1 and an evaporation passage 3 that communicates with the fuel tank 1 are provided with fuel. A diaphragm-type flow rate control valve 4 that opens and closes according to the internal pressure of the tank 1 to control the evaporation flow rate is inserted. An electromagnetic valve 10 that is normally closed and opens during a diagnostic check is provided in parallel with the flow control valve 4.

Normally, the solenoid valve 10 is closed. When the tank internal pressure exceeds a certain set pressure, the diaphragm 5 rises against the spring 7, the valve body 6 moves upward, and the flow control valve 4 opens. When the tank internal pressure is less than a certain value, the valve body 6 is pushed by the spring 7 and descends, and the flow control valve 4 is closed. The upper side of the diaphragm 5 is an atmospheric pressure chamber. And the tank internal pressure is applied to the lower side.

Reference numeral 8 is an inlet of the flow control valve 4, and 9 is an outlet, which communicate with the upper portion of the fuel tank 1 and the tank port of the canister 2, respectively. The solenoid valve 10 opens at the time of a diagnostic check and guides a negative pressure to the fuel tank 1. That is, the solenoid valve 10 is opened during the diagnostic check and acts as a bypass passage for the flow control valve 4.

As a flow rate control valve (also called a pressure control valve) 4, a diaphragm type on-off valve described in Japanese Utility Model Laid-Open No. 55-100774 is used, and as a solenoid valve 10, a solenoid valve 10 is disclosed in Japanese Patent Laid-Open No. 62-62. Those described in Japanese Patent No. 75182 are known.

[0006]

[Problems to be solved by the device]

 In the above-mentioned conventional technique, the valve element 6 is fixed to the valve seat by the adhesive component contained in the valve element 6 or the valve is similarly fixed by the adhesive component in the fluid being attached to the valve element 6 or the valve seat. However, there is a problem in that the flow valve 4, which is operated with a relatively small pressure such as the internal pressure of the fuel tank, does not operate. In other words, the sticking of the valve sometimes made it impossible to control the minute pressure.

Therefore, an object of the present invention is to provide a flow control valve capable of solving such a problem.

[0008]

[Means for Solving the Problems]

 To achieve the above object, the flow control valve of the present invention comprises a spring (19) for abutting a valve body (16) provided on a rubber diaphragm (15) against a valve seat (14), and the spring (19) when energized. An electromagnetic solenoid (21) having a plunger (24) for biasing the valve body (16) away from the valve seat (14) against the (19). When energized, the valve body (16) is separated from the valve seat (14) according to the pressure applied to the diaphragm (15) to control the flow rate.

[0009]

[Action]

 When the pressure applied to the diaphragm exceeds a certain level when the electromagnetic solenoid is de-energized, the valve element moves away from the valve seat against the spring, and the valve opens at an opening corresponding to the pressure to control the flow rate.

When the electromagnetic solenoid is energized, the plunger pulls the valve element away from the valve seat by the electromagnetic force, so the valve is forcibly opened even if the valve is stuck.

[0011]

【Example】

 1 to 3 show a first embodiment of the present invention, in which 11 is a valve body, 12 is an inlet, 13 is an outlet, 14 is an annular valve seat, 15 is a rubber diaphragm, and a valve body 16 is provided at the center. Are integrally molded.

Reference numeral 17 is a cover for hermetically fixing the outer edge of the diaphragm 15 to the valve body 11, 18 is a shell abutting on the upper surface of the diaphragm 15, and 19 is a compression spring mounted between the shell 18 and the cover 17. Then, the valve element 16 is urged downward so as to contact the valve seat 14.

Reference numeral 20 is a pressure chamber provided below the diaphragm 15 and communicates with the inflow port 12. Reference numeral 21 is an electromagnetic solenoid, and 22 is a stator, which is fixed to the valve body 11 via a disc 23. The stator 22 has a cylindrical shape, and a rod (thin portion) 25 of a plunger 24 is inserted through a vertical through hole in the center of the stator 22. The upper end of the rod 25 engages with the lower end of the central portion of the valve body 16. .

Reference numeral 26 denotes a spring having a weak force for urging the plunger 24 upward. The spring 26 has a weaker force than the spring 19 and is set to, for example, about the mass of the plunger 24.

Reference numeral 27 is a communication passage that guides the fluid from the valve seat 14 to the discharge port, and 28 is an air damper chamber provided above the electromagnetic solenoid 21 and communicates with the communication passage 27. Next, the operation of the first embodiment having such a configuration will be described.

When the electromagnetic solenoid 21 is not energized, the plunger 24 and the rod 25 are at the lower position as shown in FIG. Then, according to the internal pressure of the fuel tank applied to the pressure chamber 20 from the inflow port 12, the valve body 16 moves upward against the spring 19 and separates from the valve seat 14 to open the valve. Thus, the evaporation from the fuel tank flows through the communication passage 27 and the discharge port 13 to the canister (not shown) and is adsorbed by the activated carbon.

The air damper chamber 28 prevents the pulsation of the evaporated fuel pressure flowing to the discharge port and improves the controllability of the valve. During the diagnostic check, the electromagnetic solenoid 21 is energized, the plunger 24 is attracted to the stator 22 by the electromagnetic force, and the valve body 16 is separated from the valve seat 14 against the spring 19 together with the rod 25.

Therefore, even if the valve is fixed by the sticky substance, it is forcibly opened by the electromagnetic force. FIG. 4 shows a second embodiment of the present invention. Instead of the rod 25 integrated with the plunger 24 in the first embodiment, a rod 25A having an upper end caulked and fixed to the center of the valve body 16 is provided. The lower end is in contact with the upper end of the plunger 24.

When the electromagnetic solenoid 21 is not energized and the fuel vapor pressure from the inflow port 12 is below a certain level, the valve body 16 closely contacts the valve seat 14 and the lower end of the rod 25A as shown in FIG. The size of the rod 25A is determined by the length of the rod 25A that contacts the upper end of the plunger 24.

In this embodiment as well, when the electromagnetic solenoid 21 is energized during the diagnostic check, the plunger 24 is attracted to the stator 22 by the electromagnetic force, the rod 25A moves up, and the valve body 16 is forced to open. The valve is opened apart from the seat 14.

Therefore, both valves for the evaporation flow rate control and the diagnostic check can be integrated between the fuel tank and the canister, and the valve sticking can be eliminated.

[0022]

[Effect of device]

 Since the flow control valve of the present invention is configured as described above, the adhesion of the valve can be forcibly opened by the electromagnetic force, so that the valve is not stuck and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of the present invention.

FIG. 2 is a different aspect of the same longitudinal sectional view.

FIG. 3 is a further different aspect of the same vertical sectional view.

FIG. 4 is a vertical sectional view of a second embodiment of the present invention.

FIG. 5 is a schematic view of a prior art flow control valve provided between a fuel tank and a canister of an automobile.

[Explanation of symbols]

 14 Valve seat 15 Diaphragm 16 Valve body 19 Spring 21 Electromagnetic solenoid 24 Plunger

Claims (1)

[Scope of utility model registration request] 1. A spring for contacting a valve element provided on a rubber diaphragm with a valve seat, and an electromagnetic solenoid having a plunger for biasing the valve element against the spring when energized to separate the valve element from the valve seat. A flow rate control valve that is provided and controls the flow rate by separating the valve body from the valve seat according to the pressure applied to the diaphragm when the electromagnetic solenoid is not energized.