A pilot-operated solenoid valve

Abstract

The present invention discloses a pilot-operated solenoid valve, which includes an electromagnet assembly, an armature, a main valve body, an end cover, a main valve spool, a pilot valve spool, a pilot valve body, a push rod, a nozzle, an inlet, an outlet, a spring, an O-ring and a screw. An O-ring is provided for sealing between the pilot valve body and the push rod. There is a nozzle on the pilot valve body. The back pressure chamber of the main valve spool can be communicated with the external environment through the nozzle in the valve open state. An O-ring is used for sealing between the pilot valve body and the main valve body. The technical solution of the present invention has the characteristics of large diameter, high working pressure, environmental friendliness and convenient installation.

Description

Technical Field

[0001] The present invention relates to a pilot-operated solenoid valve, particularly a pilot-operated solenoid valve for fuel supply during the startup process of a liquid oxygen kerosene rocket engine. Background Art

[0002] During the startup process of existing rocket engines, when fuel enters the thrust chamber, generally there are two schemes as described in the book "High-Pressure Gas-Pump Liquid Oxygen Kerosene Engine" published by National Defense Industry Press in 2005 with Academician Zhang Guitian as the author:

[0003] Two-position three-way solenoid valve + pneumatic control valve scheme, as Figure 1 , mainly composed of a pneumatic control valve 1, a cylinder 2, a two-position three-way solenoid valve 3, a gas pipeline 4, a fuel inlet 5, a fuel outlet 6, a gas inlet 7, and a gas discharge port 8: This scheme requires setting up a control gas line, and at the same time, a two-position three-way solenoid valve is also needed to control the opening and closing of the gas. When it is necessary to open the pneumatic control valve, the two-position three-way solenoid valve is energized to open and introduce gas into the cylinder of the pneumatic control valve, and the pneumatic control valve will open accordingly, and the fuel enters through the inlet. When it is necessary to close the pneumatic control valve, the two-position three-way solenoid valve is de-energized to close and discharge the gas introduced into the cylinder of the pneumatic control valve from the discharge port, and the pneumatic control valve will close accordingly. The main disadvantage of this scheme is that the engine ignition process control program is complex, and there are many pipeline connections, increasing the weight of the engine;

[0004] Check valve scheme, as Figure 2 , mainly composed of a housing 1, springs 2 and 4, a sealing seat 3, a valve core 5, a discharge port 6, an outlet 7, and an inlet 8: Before the engine starts, under the action of the forces of springs 2 and 4, the valve core is in the closed position. When the fuel pressure at the valve inlet increases, the force of the fuel pressure acting on the valve core overcomes the spring force and pushes the valve core away from the sealing seat, and the fuel enters the thrust chamber. When the engine shuts down, as the inlet pressure decreases, the spring force will cause the valve core to reset to the closed position. The main disadvantage of this scheme is that the opening pressure of the check valve is a fixed value, and if the parameters do not match during the system debugging stage, it cannot be adjusted on-site. Summary of the Invention

[0005] The present invention provides a pilot-operated solenoid valve, especially for the process of fuel entering the thrust chamber during the startup process of a liquid oxygen kerosene rocket engine, which has the characteristics of large diameter, high pressure, environmental friendliness, and convenient installation;

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A pilot-operated solenoid valve consists of an electromagnet assembly (1), an armature (2), a main valve body (3), an end cover (4), a main valve spool (5), a pilot valve spool (6), a pilot valve body (7), a push rod (8), a nozzle (9), an upper seal seat (10), a lower seal seat (11), a valve inlet (12), a valve outlet (13), springs (15, 18), O-rings (14, 17, 19) and screws (16, 20). The push rod (8) is threadedly connected to the armature (2). The armature (2) is installed inside the electromagnet assembly (1). The pilot valve spool (6) is installed inside the pilot valve body (7). The pilot valve body (7) is connected to the electromagnet assembly (1) and the main valve body (3) by screws. The main valve spool (5) is installed inside the main valve body (3). The end cover (4) is connected to the main valve body (3) by screws. A nozzle is provided at the discharge port of the pilot valve body (7). The pilot valve body (7) is sealed with the push rod (8) and the main valve body (3) by O-rings;

[0008] Preferably, the pilot valve body (7) is provided with an upper seal seat (10) which forms a sealing relationship with the pilot valve spool (6) in the valve closed state. The main valve body (3) is provided with a lower seal seat (11) which forms a sealing relationship with the pilot valve spool (6) in the valve open state. The main valve body (3) is provided with a valve inlet (12) and a valve outlet (13). The valve inlet (12) and the valve outlet (13) are vertically arranged;

[0009] The back pressure chamber (21) of the main valve spool (5) is communicated with the valve inlet (12) through the lower seal seat (11) in the valve closed state. At this time, the back pressure chamber (21) is filled with fuel. When the valve is opened by energization, the armature (2) pushes the pilot valve spool (6) to move downward and separate from the upper seal seat (10) until the pilot valve spool (6) contacts the lower seal seat (11). At this time, the main valve spool (5) moves to the right under the action of the medium pressure and opens (see Figure 4 ), and the back pressure chamber (21) is communicated with the external environment through the pilot valve spool (6) (see Figure 5 ), the upper seal seat (10) and the nozzle (9), and the fuel in the back pressure chamber is collected through the nozzle pipe (9) and discharged outside the rocket engine. During the fuel discharge process, the rocket engine will not be polluted;

[0010] During the start-up ignition process of the liquid oxygen-kerosene rocket engine, when the kerosene pressure reaches a predetermined value, the pilot-operated solenoid valve is energized to open the valve and supply fuel to the thrust chamber. After the engine starts, the pilot-operated solenoid valve is de-energized to close the valve;

[0011] The advantages of the present invention compared with the prior art are as follows:

[0012] A pilot-operated solenoid valve of the present invention serves as a fuel supply control component during the startup process of a liquid oxygen / kerosene engine. It meets the working conditions of large diameter and high working pressure, simplifies the engine system, and is of great significance for improving the reliability and reducing the weight of the engine. The pilot valve body is sealed with the push rod and the main valve body using O-ring seals. The pilot valve body is provided with a nozzle, to which a pipeline can be connected to collect the kerosene during the valve opening process and discharge it outside the rocket engine, without causing pollution to the engine, ensuring environmental friendliness during the valve opening process. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 FIG. is a schematic application diagram of a prior art pneumatic control valve and a two-position three-way solenoid valve;

[0014] Figure 2 FIG. is a structure of a common check valve in the prior art;

[0015] Figure 3 FIG. is a sectional view of the pilot-operated solenoid valve when the valve of the embodiment of the present invention is in the closed state;

[0016] Figure 4 FIG. is a sectional view of the pilot-operated solenoid valve when the valve of the embodiment of the present invention is in the open state;

[0017] Figure 5 FIG. is the structure of the pilot valve spool. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] A pilot-operated solenoid valve of the present invention is composed of an electromagnet assembly 1, an armature 2, a main valve body 3, an end cover 4, a main valve spool 5, a pilot valve spool 6, a pilot valve body 7, a push rod 8, a nozzle 9, an upper seal seat 10, a lower seal seat 11, a valve inlet 12, a valve outlet 13, springs 15 and 18, O-ring seals 14, 17, 19, and screws 16 and 20. The push rod 8 is threadedly connected to the armature 2. The armature 2 is installed inside the electromagnet assembly 1. The pilot valve spool 6 is installed inside the pilot valve body 7. The pilot valve body 7 is connected to the electromagnet assembly 1 and the main valve body 3 by screws. The main valve spool 5 is installed inside the main valve body 3. The end cover 4 is connected to the main valve body 3 by screws. A nozzle 9 is provided at the discharge port of the pilot valve body 7. The pilot valve body 7 is sealed with the push rod 8 and the main valve body 3 using O-ring seals 14 and 19;

[0019] The pilot valve body 7 is provided with an upper seal seat 10, which forms a sealing relationship with the pilot valve spool 6 when the valve is in the closed state. The main valve body 3 is provided with a lower seal seat 11, which forms a sealing relationship with the pilot valve spool 6 when the valve is in the open state. The main valve body 3 is provided with a valve inlet 12 and a valve outlet 13, and the valve inlet 12 and the valve outlet 13 are vertically arranged;

[0020] The back pressure chamber 21 of the main valve core 5 is connected to the valve inlet 12 through the lower sealing seat 11 when the valve is closed. At this time, the back pressure chamber 21 is filled with fuel. When the valve is powered on to open, the armature 2 pushes the pilot valve core 6 to move downward and separate from the upper sealing seat 10 until the pilot valve core 6 contacts the lower sealing seat 11. At this time, the main valve core 5 moves to the right under the action of the medium pressure and opens (see Figure 4 ), the back pressure chamber 21 passes through the pilot valve core 6 (see Figure 5 ), the upper sealing seat 10 and the nozzle 9 are connected to the external environment, and the fuel in the back pressure chamber is collected and discharged to the outside of the rocket engine through the nozzle pipe 9. During the fuel discharge process, no pollution is generated to the rocket engine;

[0021] During the startup and ignition process of the liquid oxygen-kerosene rocket engine, when the kerosene pressure reaches a predetermined value, the pilot solenoid valve is opened to supply kerosene to the thrust chamber;

[0022] Working principle: Figure 3 , the valve is in the closed state, that is, the main valve core 5 is in contact with the main valve body 3 and sealed. At this time, the pilot valve core 6 is in contact with the upper sealing seat 10 and sealed, the lower sealing seat 11 is open, the back pressure chamber 21 of the main valve core 5 is connected to the valve inlet, which is a high-pressure state, and the valve outlet is a low-pressure state. The main valve core 5 is in the closed state under the action of the medium force and the spring force;

[0023] When the main valve core 5 needs to be opened, the solenoid assembly 1 is energized. At this time, the armature 2 is acted upon by the electromagnetic force and moves downward, driving the push rod 8 to push the pilot valve core 6, causing the pilot valve core 6 to move downward and separate from the upper sealing seat 10 until the pilot valve core 6 contacts and seals the lower sealing seat 11. The lower sealing seat 11 is closed and the upper sealing seat 10 is opened. Figure 4 As shown, the back-pressure chamber 21 of the main valve core 5 is connected to the external environment through the take-over nozzle 9 and is in a low-pressure state. Under the force of the inlet medium, the main valve core 5 moves to the right, overcoming the spring force and maintaining the open state. The pilot valve body 7, the push rod 8, and the main valve body 3 are sealed with an O-ring. During the rightward opening of the main valve core 5, the medium in the back-pressure chamber 21 is squeezed out and discharged through the take-over nozzle 9. A pipeline can be connected at the take-over nozzle 9 for collection and discharge.

[0024] The above description is only a specific embodiment of the present invention, but the protection of the present invention is not limited thereto. Any insubstantial improvements made by those skilled in the art without changing the principle should also be considered within the scope of protection of the present invention.

[0025] The contents not described in detail in the specification of the present invention belong to the prior art known to those skilled in the art.

Claims

1. A pilot-operated solenoid valve, characterized in that: The invention comprises an electromagnet assembly (1), an armature (2), a main valve body (3), an end cover (4), a main valve core (5), a pilot valve core (6), a pilot valve body (7), a push rod (8), a nozzle (9), an upper sealing seat (10), a lower sealing seat (11), a valve inlet (12), a valve outlet (13), springs (15, 18), O-rings (14, 17, 19) and screws (16, 20), wherein the push rod (8) is connected to the armature (2) by a thread, the armature (2) is installed in the electromagnet assembly (1), the pilot valve core (6) is installed in the pilot valve body (7), and the pilot valve core (6) is installed in the pilot valve body (7). The valve body (7) is connected to the electromagnet assembly (1) and the main valve body (3) via the screws (20), the main valve core (5) is installed in the main valve body (3), the end cover (4) is connected to the main valve body (3) via the screws (16), the end cover (4) is sealed to the main valve body (3) and the main valve core (5) by the O-ring (17), the nozzle (9) is provided at the discharge port of the pilot valve body (7), and the pilot valve body (7) is sealed to the push rod (8) and the main valve body (3) by the O-rings (14, 19); The pilot valve body (7) is provided with the upper sealing seat (10), which forms a sealing relationship with the pilot valve core (6) in the valve closed state; the main valve body (3) is provided with the lower sealing seat (11), which forms a sealing relationship with the pilot valve core (6) in the valve open state; the main valve body (3) is provided with the valve inlet (12) and the valve outlet (13); the valve inlet (12) and the valve outlet (13) are vertically arranged; the back pressure chamber (21) of the main valve core (5) is communicated with the valve inlet (12) through the lower sealing seat (11) in the valve closed state, and is communicated with the external environment through the upper sealing seat (10) and the take-over nozzle (9) in the valve open state.

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