In-tube solenoid gas valve

Abstract

A newly designed solenoid gas valve which including a solenoid assembly and inlet & outlet fittings is installed inside a tube. The adoption of in-line inlet and outlet configuration simplifies the procedures required for connecting the pipes and the gas flow is controlled by opening and closing the valve in a piping system. The opening and closing of the valve is operated by the pressure difference with an aid of the magnetic field. A compression spring is attached to the support cylindrical body and held against the inlet end fitting while a moving solenoid assembly is located inside the support cylindrical body. The moving solenoid assembly that consists of a stop, a flange, a sleeve and an electrical coil, is held by a second compression spring that is attached to the inside of the support cylindrical body. A small moving magnetic rod, slides inside the sleeve of the solenoid assembly. The movement of the small magnetic rod is not affected by that of the entire solenoid assembly which would reduce the stroke (the distance traveled), hence, reduce the electric power requirement. Acted by a third compression spring, the magnetic rod seals the gas outlet through the bleed orifice on the flange of the solenoid assembly. Initially, the solenoid assembly closes the outlet passage solely by the act of the first compression spring since the pressure is in equalization inside the cylindrical body. To allow the gas pass through the valve, an electrical coil is energized to create a magnetic field that causes the magnetic rod to open the bleed orifice, permitting gas flowing and generating pressure difference between the front and the back side chambers. These two chambers are separated by an o-ring on the flange of the solenoid assembly. As soon as the chamber pressure difference exceeds the spring force, the outlet passage opens. When the magnetic field ceases, the magnetic rod moves back to seal the orifice and at the same time, the pressure in the front side chamber builds up to reach a pressure equalization, the compression spring causes the solenoid assembly to close off the outlet passage.

Description

BACKGROUND OF THE INVENTION [0001] The configuration of piping systems is complex in alternative fuel vehicles. The fuel, either natural gas or hydrogen, is normally stored in a high pressure tank, controlled by solenoid gas valves when it is in operation. Generally, the space in a vehicle is limited; hence a small size of valves and piping systems is desired. In addition, having an in-line inlet and outlet ports would simplify the arrangement of piping systems. [0002] Valves are used to control the flow rate of the fuel under a specified inlet pressure. Because of the inlet pressure restrictions and temperature variations, it is difficult to design an appropriate valve that meets all the requirements for the piping systems. Solenoids of a reasonable size can typically produce a pulling force that is approximately only 1 / 100 of the force necessary to unseat a valve that is being forced shut by the high-pressure gases. To overcome this, most of the gas valves adopt a two-stage proces...

AI Technical Summary

Benefits of technology

[0006] It is the object of the present invention to provide an in-tube solenoid gas valve of the above mentioned general types which avoid the disadvantages of and improve the performance of the prior art.

[0007] It is also the object of the present invention to provide a solenoid gas valve which has intrinsic ability to reduce the opening stroke (distance) of a magnetic rod to either alleviate the electrical power required or to reduce the size of the valve. The movement of solenoid assembly is caused by the spring force and gas pressure; therefore, the opening distance of said solenoid assembly is not limited by magnitude of magnetic force generated by electrical power via electrical coil. So that, the present invention can reasonably increase gas flow rate.

[0012] Hence, in the current design, described hereafter, the stroke of the movement of magnetic rod is not affected by the required stroke of that of the solenoid assembly. The stroke of the magnetic rod is minimized and the stroke of the solenoid assembly is maximized to result in a reduction of the electrical coil size and an increase in maximum flow rate under the same conditions of the same inlet pressure and the same power supply.

[0013] When the solenoid gas valve is designed in accordance with the present invention, it avoids the disadvantages of the prior art and provide for the above-specified advantages.

Problems solved by technology

The configuration of piping systems is complex in alternative fuel vehicles.

Because of the inlet pressure restrictions and temperature variations, it is difficult to design an appropriate valve that meets all the requirements for the piping systems.

This becomes problematic if the pressure of the inlet is increased.

An increase in number of turns in a coil also increases the size of the solenoid assembly, which is undesirable.

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