Field of the Solenoid Valve Invention

The present invention generally relates to control solenoid valve and, more particularly, relates to a control solenoid valve capable of reducing the energy consumption thereof.

BACKGROUND OF THE INVENTION

As is well known in the art, control valves have frequently been used to control and supply a working fluid, such as air, to a working device. Typically, these control valves employ a moveable valve spool disposed in a valve housing. The valve housing includes a plurality of fluid passages that are selectively interconnected in response to movement of the valve spool so as to control the flow of the fluid and, thus, the output of the control valve.

Conventional control valves often employ a solenoid valve mounted thereto for actuating the valve spool. The solenoid valve is controlled via an electrical input signal between a first position, where the solenoid valve is de-energized so as to close a fluid passage between an input pilot pressure and an output controlling pressure, and a second position, where the solenoid is energized via the electrical input so as to open a passageway between the input pilot pressure and the output controlling pressure.

It should be readily appreciated to one skilled in the art that in order to apply a constant controlling pressure, the electrical control signal must continue to energize the solenoid valve. That is, in order for a conventional control valve to maintain the spool in a predetermined position, it is necessary to maintain a constant control pressure upon one side of the spool. Therefore, in order to maintain this constant control pressure on the spool, it is necessary to maintain the solenoid valve in an opened and, thus, energized state. Moreover, it is necessary to employ full line fluid pressure to actuate the spool into the predetermined positions. Therefore, it should be understood that if it is preferred that the control valve be in this predetermined position for fluid output, electrical energy consumption to drive compressors to supply full line pressure will increase.

Accordingly, there exists a need in the relevant art to provide a control valve capable of producing an output of working fluid to be used with a conventional working device that is capable of minimizing the energy consumed during actuation. Furthermore, there exists a need in the relevant art to provide a control valve that maintains the position of a control element at a pressure less than full line pressure. Still further, there exists a need in the relevant art to overcome the disadvantages of the prior art.

SUMMARY OF THE INVENTION

A control valve system having an advantageous construction is provided. The control valve system includes a slidable valve positionable in a first position, where fluid communication is established between the inlet and the first output; a second position, where fluid communication is established between the inlet and the second output; and a third position, where fluid communication is prevented between the inlet and the first or second output. A solenoid valve assembly is coupled in fluid communication with the inlet and is positionable in an actuated position, where fluid communication is established with the inlet to move the valve from the first position to the second position, and a deactuated position. A feedback passage extends between the first output and the valve so as to position the valve in the third position in response to fluid pressure within the first output.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a control valve system according to a first embodiment of the present invention illustrated in a normal operation mode where the solenoid valve assembly is energized;

FIG. 2 is a cross-sectional view illustrating the control valve system of FIG. 1 wherein the solenoid valve assembly is de-energized;

FIG. 3 is a cross-sectional view illustrating the control valve system of FIG. 1 being maintained in a predetermined position while the solenoid valve assembly remains de-energized and the valve spool is in an equilibrium position;

FIG. 4 is a circuit diagram illustrating the control valve system according to the first embodiment of the present invention;

FIG. 5 is a cross-sectional view of a control valve system according to a second embodiment of the present invention illustrated in an initial position where the first and second solenoid valve assemblies are de-energized and the piston is stationary;

FIG. 6 is a cross-sectional view illustrating the control valve system of FIG. 5 wherein the first solenoid valve assembly is energized and the second solenoid valve assembly is de-energized;

FIG. 7 is a cross-sectional view illustrating the control valve system of FIG. 5 wherein the first and second solenoid valve assemblies are de-energized and the piston continues to extend;

FIG. 8 is a cross-sectional view illustrating the control valve system of FIG. 5 wherein the first solenoid valve assembly is de-energized and the second solenoid valve assembly is energized;

FIG. 9 is a cross-sectional view illustrating the control valve system of FIG. 5 wherein the first and second solenoid valve assemblies are de-energized and the piston continues to retract;

FIG. 10 is a cross-sectional view illustrating the control valve system of FIG. 5 wherein the first and second solenoid valve assemblies are de-energized and the piston is stationary;

FIG. 11 is a circuit diagram illustrating the control valve system according to the second embodiment of the present invention;

FIG. 12 is a circuit diagram of a control valve system according to a third embodiment of the present invention illustrated in an initial position where the solenoid valve assembly is de-energized and the piston is stationary;

FIG. 13 is a schematic diagram illustrating the feedback passage being disposed externally from the housing; and

FIG. 14 is a schematic diagram illustrating the feedback passage being disposed internally in the housing.

The description of the solenoid valve invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.