Pilot operated pressure control valve

Abstract

This invention belongs to the field of fuel control and relates to a pilot-operated constant pressure valve. It includes a housing, cover, pressure regulating spring, stop seat, return spring, bushing, valve, nozzle, and pilot valve. It can maintain a constant output pressure in systems with varying operating conditions, improving the valve's anti-interference capability and providing a more stable constant pressure fuel output. It solves the problem of outlet constant pressure deviation caused by changes in inlet fuel pressure, outlet fuel consumption flow rate, and other conditions, making the system more stable and reliable.

Description

Technical Field

[0001] This invention belongs to the field of fuel control and relates to a pilot-operated constant pressure valve. Background Technology

[0002] Constant pressure valves are commonly used in fuel control systems to regulate fuel pressure and supply it to electro-hydraulic switching elements and actuators. Under certain circumstances, significant deviations in the constant pressure can lead to poor control accuracy or even malfunction. Conventional constant pressure valves experience deviations in outlet constant pressure when conditions such as inlet fuel pressure and outlet fuel consumption flow change, affecting system stability. Summary of the Invention

[0003] Purpose of the invention

[0004] This type of pilot-operated constant pressure valve was designed to improve the anti-interference capability of the constant pressure valve and output a more stable constant pressure fuel.

[0005] The purpose of this invention is to develop a constant pressure valve that outputs constant pressure in systems with varying operating conditions.

[0006] Technical solution

[0007] This invention is achieved through the following technical solution:

[0008] A pilot-operated constant pressure valve includes a housing, a cover, a pressure regulating spring, a stop seat, a return spring, a bushing, a valve, an oil nozzle, and a pilot valve.

[0009] A bushing is installed within the housing, containing a valve. A stop seat is mounted on the left side of the bushing, and a return spring is installed between the stop seat and the valve. A cover is installed on the left side of the stop seat, containing a pressure regulating spring. A pilot valve is connected to the right side of the pressure regulating spring. An oil nozzle 8 is located between the oil return hole K1 on the cover and the oil return passage Y1. During initial installation, the valve is in the right stop position under the action of the return spring, and the pilot valve is in the right stop position under the action of the pressure regulating spring. High-pressure fuel enters the P3 chamber through the inlet hole K4 on the valve. The fuel in the P3 chamber enters the P2 chamber through the narrow hole K3, and also goes directly from the constant pressure oil outlet passage Y3 to the components that consume constant pressure oil.

[0010] Furthermore, in the initial state, cavity P2 is a dead space, and its pressure is equal to that of cavity P3.

[0011] Furthermore, when the pressure in chamber P3 rises above the set pressure of the constant pressure oil, the pilot valve opens, and the pressure in chamber P2 drops. At this time, the forces on both ends of the valve are unbalanced, and the valve moves to the left.

[0012] Furthermore, as the valve moves to the left, the opening area of ​​K4 gradually decreases, and therefore, the pressure of P3 also decreases. Until a certain position, when the pressure of P3 is basically equal to the set pressure value of the constant pressure oil, the pilot valve closes under the action of the pressure regulating spring, and the pressure of P2 chamber becomes equal to the pressure of P3 chamber again, while the valve position remains unchanged.

[0013] Furthermore, when the pressure in chamber P3 decreases, the pressure in chamber P2 has not yet decreased. The valve moves to the right, and the opening area of ​​the inlet orifice K4 increases, causing the pressure in chamber P3 to rise to the set pressure value.

[0014] Furthermore, in the valve, the set pressure of the constant pressure oil is directly proportional to the pressure of the regulating spring.

[0015] Furthermore, the function of the return spring is to provide a small force to return the valve to its original position when the valve stops working or when the valve needs to move to the right.

[0016] Furthermore, the pilot-operated constant pressure valve can keep the output constant pressure oil pressure basically stable at the set value.

[0017] Technical effect

[0018] The improved anti-interference capability of the constant pressure valve results in a more stable constant pressure fuel output, solving the problem of outlet constant pressure deviation caused by changes in inlet fuel pressure, outlet fuel consumption flow rate, and other conditions, thus making the system more reliable. Attached Figure Description

[0019] Figure 1 A schematic diagram of the pilot-operated constant pressure valve described in this invention.

[0020] Figure 2 Bushing 2D diagram

[0021] Figure 3 Two-dimensional diagram of the valve

[0022] Figure 4 2D diagram of pilot valve

[0023] Among them, 1-shell, 2-cover, 3-pressure regulating spring, 4-stop seat, 5-return spring, 6-bushing, 7-valve, 8-oil nozzle, 9-pilot valve, K1-oil return hole, K2-pilot valve hole, K3-slender hole, K4-inlet type hole, K5-pressure relief type hole, P1-pressure chamber 1, P1-pressure chamber 2, P1-pressure chamber 3, Y1-oil return circuit, Y2-inlet high-pressure fuel circuit, Y3-constant pressure oil outlet circuit. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments. The following description represents only a portion of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] Examples of embodiments of the present invention Figure 1 As shown: A bushing (6) is installed in the housing (1), a valve (7) is installed in the bushing, a stop seat (4) is installed on the left side of the bushing, a return spring (5) is installed between the stop seat and the valve, a cover (2) is on the left side of the stop seat, a pressure regulating spring (3) is installed inside the cover, a pilot valve (9) is connected to the right side of the pressure regulating spring, and an oil nozzle (8) is installed between the oil return hole (K1) of the cover and the oil return passage (Y1). During initial installation, the valve is in the right stop position under the action of the return spring, and the pilot valve is in the right stop position under the action of the pressure regulating spring. The inlet high-pressure fuel enters the P3 chamber through the inlet hole (K4) on the valve. The fuel in the P3 chamber enters the P2 chamber through the narrow hole (K3) on one hand, and directly from the constant pressure oil outlet passage (Y3) to the various components that consume constant pressure oil on the other hand. Initially, chamber P2 is a dead chamber, and its pressure equals that of chamber P3. When the pressure in chamber P3 rises above the set pressure of the constant pressure oil, the pilot valve opens, and the pressure in chamber P2 decreases. At this time, the forces on both ends of the valve are unbalanced, and the valve moves to the left. As the valve moves to the left, the opening area of ​​K4 gradually decreases, thus the pressure in P3 also decreases until it reaches a position where the pressure in P3 is approximately equal to the set pressure of the constant pressure oil. At this point, the pilot valve closes under the action of the pressure regulating spring, and the pressure in chamber P2 becomes equal to that in chamber P3 again, while the valve position remains unchanged. Similarly, when the pressure in P3 decreases, the pressure in chamber P2 has not yet decreased, and the valve moves to the right, increasing the opening area of ​​the inlet orifice K4, causing the pressure in chamber P3 to rise to the set pressure value. In this valve, the set pressure of the constant pressure oil is only related to the pressure regulating spring (3), while the function of the return spring (5) is to provide a little force to return the valve when the valve stops working or when the valve needs to move to the right. Its stiffness and pre-compression amount are very small, and its influence on the valve can generally be ignored in the working process.

[0026] Several components (1-housing, 2-cover, 3-pressure regulating spring, 4-stop seat, 5-return spring, 6-bulb, 7-valve, 8-oil nozzle, 9-pilot valve).

[0027] like Figure 1As shown, the pilot valve is located on the left side of the constant pressure valve, the constant pressure oil is output on the right side, and the fuel is supplied after the constant pressure oil passes through a narrow orifice on the left side. When the outlet constant pressure oil pressure is less than the set pressure value, the pilot valve closes, the fuel pressure on both sides of the constant pressure valve is equal, and the valve position remains unchanged. When the inlet pressure suddenly increases and the outlet pressure exceeds the set value, the fuel on the left side of the constant pressure valve opens the pilot valve, reducing the pressure before the pilot valve. Due to the narrow orifice design, the constant pressure oil can be kept stable for a short time, causing the constant pressure valve to move to the left. The inlet throttling orifice decreases, further reducing the constant pressure oil pressure. When the constant pressure oil pressure equals the set value, and the valve stabilizes at a certain position, the pilot valve closes, the pressure on both sides of the constant pressure valve is balanced again, and the valve stabilizes at this position. The set pressure of the constant pressure valve is only related to the pressure regulating spring; the return spring has very low stiffness and its influence on the valve position can be ignored in the calculation.

[0028] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein. The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A pilot operated pressure retaining valve characterized by, Includes housing, cover, pressure regulating spring, stop seat, return spring, bushing, valve, nozzle, and pilot valve. A bushing is installed in the housing, and a valve is installed in the bushing. A stop seat is installed on the left side of the bushing, and a return spring is installed between the stop seat and the valve. A cover is installed on the left side of the stop seat, and a pressure regulating spring is installed inside the cover. A pilot valve is connected to the right side of the pressure regulating spring. An oil nozzle is installed between the oil return hole K1 of the cover and the oil return passage Y1. During initial installation, the valve is in the right stop position under the action of the return spring, and the pilot valve is in the right stop position under the action of the pressure regulating spring. The inlet high-pressure fuel enters the P3 chamber through the inlet hole K4 on the valve. The fuel in the P3 chamber enters the P2 chamber through the narrow hole K3, and also goes directly from the constant pressure oil outlet passage Y3 to the various components that consume constant pressure oil. In the initial state, P Chamber 2 is a dead chamber, and its pressure is equal to that of chamber P3. When the pressure in chamber P3 rises above the set pressure of the constant pressure oil, the pilot valve opens, and the pressure in chamber P2 drops. At this time, the forces on both ends of the valve are unbalanced, and the valve moves to the left. As the valve moves to the left, the opening area of ​​K4 gradually decreases, so the pressure in P3 also decreases until it reaches a certain position where the pressure in P3 is basically equal to the set pressure of the constant pressure oil. At this point, the pilot valve closes under the action of the pressure regulating spring, and the pressure in chamber P2 is equal to that in chamber P3 again, while the valve position remains unchanged. When the pressure in P3 drops, the pressure in chamber P2 has not yet dropped, so the valve moves to the right, and the opening area of ​​the inlet orifice K4 increases, causing the pressure in chamber P3 to rise to the set pressure value.

2. A pilot operated pressure control valve according to claim 1, wherein In the valve, the set pressure of the constant pressure oil is directly proportional to the pressure of the pressure regulating spring.

3. A pilot operated pressure control valve according to claim 1 wherein, The function of the return spring is to provide a small force to return the valve to its original position when the valve stops working or when the valve needs to move to the right.

4. A pilot operated pressure control valve according to claim 1 wherein, Pilot-operated constant pressure valves can keep the output constant pressure oil pressure basically stable at the set value.

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