KR101829321B1 - Two-step open type poppet valve and its control method - Google Patents

Abstract

A two-stage openable poppet valve and a control method thereof are disclosed. The two-stage openable poppet valve includes: a valve housing having an inlet through which a fluid is introduced and an outlet through which the fluid is discharged; and a valve stem being opened/closed while being raised by the pressure of pilot gas inside the valve housing and lowered by a return spring. Further, the poppet valve includes a valve control means provided in the valve housing and configured to, when the valve stem rises, stop the valve stem at a predetermined position for a predetermined period of time and then allow the valve stem to be completely raised by releasing a rise limit of the valve stem.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a two-step open type poppet valve,

The present invention relates to, for example, a two-stage open-type poppet valve applied to a liquid rocket and a control method thereof.

Particularly, when the outlet of the poppet valve is opened, the opening degree of the liquid rocket engine is reduced in the initial stage of ignition and startup, and the opening degree of the liquid rocket engine is normally expanded after the startup of the liquid rocket engine. Stage open-type poppet valve and a control method thereof, which are capable of eliminating adverse effects of engine starting characteristics due to an unnecessarily large amount of oxidant being injected at the initial stage of ignition and start-up.

Generally, a liquid rocket is a flight device that mixes a liquid fuel and an oxidizer in a combustion chamber, and ejects the exhaust gas through a nozzle to obtain propulsive force based on the action-reaction principle. Such liquid rockets are preferred over solid rockets because they have the advantage of easily controlling the amount of combustion through valves and pumps.

In order to regulate the amount of combustion of the liquid rocket, a flow control valve is required to regulate the flow rate of the fuel and the oxidant supplied from the combustion chamber. A typical poppet valve is mainly used as the flow control valve. The poppet valve has a structure in which an opening / closing member, such as a poppet, is reciprocably disposed in a flow path of a valve, and the opening degree is adjusted while selectively opening and closing the flow channel by the movement of the poppet.

FIG. 1 is a front sectional view of a conventional poppet valve, and FIG. 2 is a sectional view of a conventional poppet valve after opening. According to these figures, a conventional poppet valve 10 includes a valve housing 20, And a valve stem (30).

The valve housing 20 has a chamber 21 in which the valve stem 30 can be lifted and lowered and a pilot gas injection port 22 through which a pilot gas is injected is provided at an upper portion of the chamber 21 have. An oxidant inlet 23 through which the oxidant flows into the lower portion of the chamber 21 is provided, and an oxidant outlet 24 through which the oxidant introduced into the chamber 21 is discharged is provided on the other side. In addition, a spring mounting portion 25 is vertically provided in the chamber 21.

The valve stem 30 is provided with a piston 31 at an upper end in the figure and a valve portion 32 for selectively opening and closing the oxidant outlet 24 at the lower end of the valve stem 30.

A return spring 40 is provided in the spring mounting portion 25 to exert an elastic force to push the valve portion 32 of the valve stem 30 toward the oxidant outlet 24.

1, the valve portion 32 of the valve stem 30 is brought into close contact with the oxidizing agent discharge port 24 by the elastic force of the return spring 40, so that the oxidizing agent discharge port 24, When the pilot gas is injected into the pilot gas injection port 22, the injection pressure is applied to the bottom surface of the piston 31, and the valve stem 30 is moved upward.

Thus, as the valve portion 32 is separated from the oxidant discharge port 24, the oxidant discharge port 24 is fully opened so that the oxidant is discharged and supplied to the liquid rocket engine.

However, in the conventional poppet valve 10 described above, the valve stem 30 rises to the top dead center in one step and the oxidant outlet 24 is completely opened, so that even when the liquid rocket engine is in the initial stage of ignition and starting, Liquid rocket engine.

In addition, a relatively small amount of oxidizing agent may be supplied at the initial stage of ignition and startup of the liquid rocket engine, unlike at the time of starting the engine, but the oxidizing agent is excessively supplied unnecessarily.

1. Registration patent publication No. 10-0589765 (motor-driven liquid rocket flow control valve using two-stage sliding member)

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the opening degree of the poppet valve at the opening of the oxidant outlet and at the initial stage of ignition and starting of the liquid rocket engine and to normally expand the opening degree after the starting of the liquid rocket engine is completed Stage open type poppet valve in which an adverse influence of an engine starting characteristic due to an unnecessarily large amount of an oxidant injected at the initial stage of ignition and start-up can be solved.

Another object of the present invention is to provide a control method of the two-stage open type poppet valve.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

The above object is achieved by a valve device comprising: a valve housing having an inlet through which a fluid flows and an outlet through which fluid is discharged; And a valve stem which is moved upward by the pressure of the pilot gas in the valve housing and descends by the return spring and opens and closes the discharge port. The valve stem is provided in the valve housing, And then valve control means for releasing the upward restriction of the valve stem to be fully lifted, can be achieved by the two-stage open poppet valve.

Also, the above-mentioned object is achieved by a two-stage open type poppet valve for controlling an amount of an oxidant input to a liquid rocket, comprising: a valve housing provided with an inlet through which the oxidant flows, an outlet through which the oxidant is discharged, A valve stem provided in the valve housing so as to be able to move up and down, a piston at an upper end thereof, and a valve stem at a lower end thereof for selectively opening and closing the outlet; A return spring exerting an elastic force to push the valve stem toward the discharge port while being installed in the spring mounting portion; And a valve control means provided in the valve housing for stopping the valve stem at a predetermined position for a predetermined time when the valve stem rises, and then releasing the upward restriction of the valve stem so that the valve stem is fully lifted. .

The valve control means includes a lower case communicating with the valve housing, a case consisting of an upper case integrally connected by the lower case and a hollow connection portion, a piston sealing the upper portion of the upper case, A cover provided with a pilot gas exhaust port; A valve stopper installed inside the connection portion so as to be slidable upward and downward to limit the upward movement of the valve stem; A stopper spring supported by the cover and exerting an elastic force to push the valve stopper downward; And a connection pipe for interconnecting the pilot gas discharge port and the space below the valve stem piston portion of the valve housing.

And a length variable adapter detachably coupled to a lower portion of the valve stopper to make the length of the valve stopper longer or shorter.

And an airtight piston tightly coupled to the valve stopper and having an outer circumferential surface closely contacting the inner circumferential surface of the upper case.

And an orifice provided inside the valve housing side of the connecting pipe for reducing a diameter of a part of the inner diameter of the connecting pipe.

The above object is also achieved by a pilot gas control method for controlling opening of a two-stage open-type poppet valve as described above, comprising: a pilot gas supplying step for causing a pilot gas to flow through the valve control means; A valve stem lifting step for lifting the valve stem by the pressure of the supplied pilot gas; A valve lift-restricting step of restricting an upward movement of the valve stem by a valve stopper positioned on the ascending path during the lifting of the valve stem, thereby partially opening the outlet; A pilot gas interruption step of stopping the injection of the pilot gas; And a valve fully lifting step for lifting the valve stem up to the top dead center by pushing up the valve stopper by a discharge output of the oxidant discharged through the outlet port, Can be achieved by the opening control method of Fig.

The present invention adopts a two-stage opening system in which the degree of opening of the oxidant outlet is reduced at the initial stage of ignition and startup of the liquid rocket engine by the improved poppet valve, and the opening degree is normally expanded after the start of the liquid rocket engine is completed And it has an advantage that an adverse influence of an engine starting characteristic due to an unnecessarily large amount of oxidant being injected at the initial stage of ignition and startup can be solved.

1 is a cross-sectional view of a conventional poppet valve, in which the oxidant outlet is closed
2 is a cross-sectional view of a conventional poppet valve, in which the oxidant outlet is open
3 is a perspective view of a poppet valve according to the present invention.
4 is a cross-sectional view of a poppet valve according to the present invention, in which the oxidant outlet is closed
FIG. 5 is a sectional view of a poppet valve according to the present invention, in which the oxidant outlet is partially opened
6 is a cross-sectional view of a poppet valve according to the present invention, in which the oxidant outlet is fully opened

In order to fully understand the structure and effects of the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms and various modifications may be made. It will be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

In this specification, when an element is referred to as being on another element, it may be directly formed on another element, or a third element may be interposed therebetween. Further, in the drawings, the thickness of the components is exaggerated for an effective description of the technical content. The same reference numerals denote the same elements throughout the specification.

Embodiments described herein will be described with reference to cross-sectional views and / or plan views that are ideal illustrations of the present invention. In the drawings, the thicknesses of the films and regions are exaggerated for an effective description of the technical content. Thus, the regions illustrated in the figures have schematic attributes, and the shapes of the regions illustrated in the figures are intended to illustrate specific types of regions of the elements and are not intended to limit the scope of the invention. Although the terms first, second, third, etc. in the various embodiments of the present disclosure are used to describe various components, these components should not be limited by these terms. These terms have only been used to distinguish one component from another. The embodiments described and exemplified herein also include their complementary embodiments.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms "comprises" and / or "comprising" used in the specification do not exclude the presence or addition of one or more other elements.

FIG. 3 is a perspective view of the poppet valve according to the present invention, FIG. 4 is a sectional view of the poppet valve according to the present invention, and FIG. 5 is a sectional view of the poppet valve according to the present invention, FIG. 6 is a sectional view of a poppet valve according to the present invention, in which the oxidant outlet is fully opened. FIG.

According to these drawings, the poppet valve 100 according to the present invention is used, for example, for supplying or shutting off the oxidizing agent to the engine of the liquid rocket. The valve housing 110, the valve stem 120, (130).

The valve housing 110 serves as a housing for the valve stem 120. A chamber 111 for installing the valve stem 120 may be provided in the valve stem 110, An inflow port 112 through which the oxidant flows into the lower portion and a discharge port 113 through which the oxidant is discharged and a spring mounting portion 114 may be provided.

The valve stem 120 serves to open and close the discharge port 113. The valve stem 120 is installed in the valve housing 110 so as to be able to move up and down and includes a piston 121 at an upper end thereof, And a valve portion 122 for selectively opening and closing the discharge port 113 may be provided.

The valve control means 130 is provided in the valve housing 110 to stop the valve stem 120 at a predetermined position for a predetermined time when the valve stem 120 is lifted, It can be constructed by mixing mechanical and fluid pressure systems.

Specifically, the valve control means 130 may include a case 131, a cover 132, a valve stopper 133, a stopper spring 134, and a connecting pipe 135.

The case 131 may include a lower case 131a communicating with the valve housing 110 and an upper case 131b connected to the lower case 131a by a hollow connection part 131c.

Here, the lower case 131a may be screwed into the valve housing 110. For example, a female screw may be formed on the inner circumferential surface of the lower case 131a, and a male screw may be formed on the outer circumferential surface of the upper end of the valve housing 110 so that the female screw and the male screw are engaged. This joint must be designed to take into account the confidentiality of the joint.

In addition, a communication port 131d communicating with the outside (atmospheric pressure) may be formed on one side of the lower case 131a to smoothly move the valve stem 120 up and down.

The cover 132 serves to seal the opened upper portion of the upper case 131b and includes a pilot gas injection port 132a for injecting the pilot gas into the upper case 131b, A pilot gas discharge port 132b for discharging the pilot gas in the pilot pipe 131b to the connecting pipe 135 may be provided.

The valve stopper 133 is for restricting the lifting position of the valve stem 120 and may be installed in the connection portion 131c so as to be slidable up and down.

Here, the valve stopper 133 may be provided with a variable-length adapter 133a to vary the length thereof. The valve stopper 133 can control the stop position of the valve stem 120 in accordance with the length of the valve stopper 133. Replacing the valve stopper 133 itself is troublesome, This can be realized by the removable length variable adapter 133a.

That is, after the variable length adapters 133a having different lengths are provided, if necessary, the variable length adapters 133a are fastened to the valve stoppers 133 to easily attach the variable length adapters 133a to the valve stoppers 133 without disassembling the valve stoppers 133 The length can be varied. Various methods such as a screw method or a forced fitting method can be applied to the joining method.

Also, a hermetic piston 133b may be coupled to the valve stopper 133 to block pilot gas from entering the valve housing 110. The outer circumferential surface of the airtight piston 133b is closely attached to the inner circumferential surface of the upper case 131b so that the upper case 131b and the valve housing 110 can be shut off.

The stopper spring 134 exerts an elastic force to push the valve stopper 133 downward while being supported by the cover 132 so that the valve stopper 133 is always urged downward .

The connection pipe 135 serves to supply the pilot gas in the upper case 131b to the valve housing 110. The pilot gas exhaust port 132b and the valve stem 110 of the valve housing 110 120) are connected to each other. Accordingly, the pilot gas in the upper case 131b is press-fed to the lower side of the piston portion 121 of the valve stem 120 through the connecting pipe 135, so that the valve stem 120 is lifted by the pressure force .

Here, an orifice 135a may be provided in the valve housing 110 of the connection pipe 135, that is, inside the outlet side from which the pilot gas is discharged, in which the diameter of the connection pipe is reduced. This orifice 135a causes a pressure difference between the lower space of the piston 121 of the valve stem 120 and the upper space of the upper case 131b so that the pistons 121 The pilot gas in the lower space of the upper case 131b is rapidly discharged into the upper space of the upper case 131b in a relatively low pressure state to thereby smooth the rise of the valve stem 120. [

Hereinafter, the operation of the present invention will be described (see Figs. 4 to 6). The control method of the poppet valve according to the present invention will be described with reference to an operation explanation.

4, when the discharge port 113 is closed, since the pilot gas is not supplied, the valve stem 120 is subjected to a downward force which is dominated by the elastic force of the return spring 115 . Therefore, since the valve portion 122 of the valve stem 120 is closely attached to the discharge port 113 to block the discharge port 113, the oxidizing agent is not supplied to the liquid rocket engine.

5, when the pilot gas is injected into the pilot gas injection port 132a, the injected pilot gas flows through the upper case 131b, the pilot gas discharge port 132b, and the connection pipe 135 And is sent to the space below the piston 121 of the valve stem 120. Accordingly, since the piston 121 is lifted by the force of the pilot gas, the entire stem 120 is lifted up.

In this process, that is, in the course of the valve stem 120 being lifted up, it is stopped at a predetermined position as it hits the valve stopper 133 provided on the rising stem. Therefore, the discharge port 113 will be opened small so that the amount of the oxidizing agent discharged through it becomes small. This can solve the existing problems that adversely affect the engine startup characteristics when applied to the ignition and startup of a liquid rocket engine that does not require a large supply of oxidizer.

6, when the supply of the pilot gas is interrupted, the force lifted from the valve stem 120 is extinguished, and the inside of the upper case 131b is also atmospheric pressure The valve stem 120 receives only the elastic force of the return spring 115 and the valve stopper 133 receives only the elastic force of the stopper spring 134.

The valve stem 120 receives the elastic force of the stopper spring 134 from the point stopped by the valve stopper 133 and pushes the valve stopper 133 by the discharge output of the oxidant discharged through the discharge port 113 And rise to the top point. Thereby, the discharge port 113 is opened at the maximum, and a large amount of the oxidizing agent is supplied for the operation of the liquid rocket engine.

At this time, the orifice 135a provided in the connecting pipe 135 causes a pressure difference between the space below the piston 121 of the valve stem 120 and the space above the upper case 131b, The pilot gas in the lower space of the piston 121 which is in the relatively high pressure state during the decompression process is quickly discharged to the space above the upper case 131b in the relatively low pressure state to smoothly raise the valve stem 120 do.

As described above, by the poppet valve, the opening degree of the oxidant outlet is reduced in the initial stage of ignition and startup of the liquid rocket engine, and the opening degree of the liquid rocket engine is normally increased after the startup of the liquid rocket engine. This has an advantage that an adverse effect of the engine starting characteristics due to the unnecessarily large amount of oxidant being injected at the initial stage of ignition and startup can be solved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the present invention. It is obvious that the modification or improvement is possible.

It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

100: Poppet valve 110: Valve housing
111: chamber 112: inlet
113: outlet 114: spring mounting portion
115: return spring 120: valve stem
121: piston portion 122: valve portion
130: valve control means 131: case
132: Cover 133: Valve stopper
133a: variable length adapter 134: stopper spring
135: connecting pipe

Claims (7)

A valve housing having an inlet through which the fluid flows and an outlet through which the fluid is discharged; A valve stem which is raised by the pressure of the pilot gas in the valve housing and which is opened and closed by the return spring while being lowered by the return spring,
Further comprising a valve control means provided in the valve housing for stopping the valve stem at a predetermined position for a predetermined time when the valve stem rises,
The valve control means includes a lower case communicating with the valve housing, a case consisting of an upper case integrally connected by the lower case and a hollow connection portion, a case sealing the open upper portion of the upper case, A valve stopper for restricting the upward movement of the valve stem, a stopper spring for exerting an elastic force to push the valve stopper downward while being supported by the cover, And a connection pipe interconnecting the pilot gas discharge port and the space below the valve stem piston portion of the valve housing.
As a two-stage open-type poppet valve for controlling the amount of oxidant input to the liquid rocket,
A valve housing having an inlet through which the oxidant flows, an outlet through which the oxidant is discharged, and a spring mounting portion;
A valve stem provided in the valve housing so as to be able to move up and down, a piston at an upper end thereof, and a valve stem at a lower end thereof for selectively opening and closing the outlet;
A return spring exerting an elastic force to push the valve stem toward the discharge port while being installed in the spring mounting portion; And
And a valve control means provided in the valve housing for allowing the valve stem to stop at a predetermined position for a predetermined time when the valve stem rises,
The valve control means includes a lower case communicating with the valve housing, a case made of an upper case integrally connected by the lower case and a hollow connection portion, a case sealing the open upper portion of the upper case, A valve stopper for restricting the upward movement of the valve stem, a stopper spring for exerting an elastic force to push the valve stopper downward while being supported by the cover, And a connection pipe interconnecting the pilot gas discharge port and the space below the valve stem piston portion of the valve housing.
delete 3. The method of claim 2,
Further comprising a length variable adapter detachably coupled to a lower portion of the valve stopper to increase or decrease the length of the valve stopper.
3. The method of claim 2,
And an airtight piston tightly coupled to the valve stopper and having an outer circumferential surface closely contacting the inner circumferential surface of the upper case.
3. The method of claim 2,
Further comprising an orifice provided within the valve housing side of the connecting pipe for diametrically dimensioning a portion of the inner diameter of the connecting pipe.
A two-stage open type poppet valve opening control method according to any one of claims 2 and 4,
A pilot gas supply step for allowing the pilot gas to flow through the valve control means;
A valve stem lifting step for lifting the valve stem by the pressure of the supplied pilot gas;
A valve lift-restricting step of restricting an upward movement of the valve stem by a valve stopper positioned on the ascending path during the lifting of the valve stem, thereby partially opening the outlet;
A pilot gas interruption step of stopping the injection of the pilot gas; And
And a valve lifting step of lifting the valve stem to a top dead center by pushing up the valve stopper by a discharge output of the oxidant discharged through the outlet, thereby allowing the outlet to be fully opened. Opening degree control method.

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