Stepping motor driven continuously adjustable micro nozzle based on hydraulic follow-up mechanism

Abstract

The invention relates to the technical field of hydraulic devices, and particularly discloses a stepping motor driven continuously adjustable micro nozzle based on a hydraulic follow-up mechanism, which comprises a lower valve body, a cone valve core, an upper valve body, a control valve core, an integrated stepping motor and a connecting accessory. Through the high-precision micro-step adjusting capacity of the stepping motor, the control valve element is driven to conduct accurate feeding and retreating linear motion, so that different flow channels in the cone valve element are opened, the hydraulic pressure difference of the upper cavity and the lower cavity is formed, and therefore the following valve element is pushed to follow the motion of the control valve element; the purpose of changing the throttling face between the valve element of the cone valve and the lower section cavity of the valve body is achieved, high-precision adjustment and control over the flow of media flowing through the nozzle hole are achieved, and the cone valve has the advantages of being continuously adjustable, quick in response, high in stability, capable of saving energy and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic devices, and particularly to a stepping motor-driven continuously adjustable micro-nozzle based on a hydraulic servo mechanism. Background Art

[0002] A ramjet engine is a combustion mode that mainly uses oxygen in the air. It utilizes the oxygen in the air to chemically react with the carried fuel to form thrust. With its characteristics of high speed and high efficiency, it has a wide range of applications in the military and aerospace fields. However, during the operation of a ramjet engine, it faces many technical challenges. One of the most critical issues is how to improve the fuel mixing and combustion efficiency in the combustion chamber. In a supersonic combustion chamber, the airflow velocity can reach kilometers per second, while the residence time of fuel in it is only on the order of milliseconds. Such extreme operating conditions make the fuel mixing and combustion processes extremely complex. The short residence time of fuel in the combustion chamber results in incomplete combustion reactions before being carried out by the high-speed airflow, leading to insufficient fuel mixing and incomplete combustion. This uneven combustion phenomenon not only reduces the combustion efficiency but may also cause local overheating, seriously affecting the structural integrity and lifespan of the engine. Therefore, in order to more precisely regulate and control the combustion process, there is an urgent need for a self-regulating injection scheme for supersonic combustion chambers that can adapt to changes in fuel flow rate and mixing requirements under various operating conditions.

[0003] However, the existing injectors on the market have the following problems:

[0004] 1. Fixed nozzles cannot independently achieve injection regulation and are difficult to meet the requirements of multi-nozzle collaborative injection;

[0005] 2. Piezoelectric injectors only have two states: open and closed, and cannot continuously adjust the flow rate. Even when using the PWM method to continuously adjust the flow rate, there are also problems of low regulation accuracy;

[0006] 3. The flow rate regulation range of the pintle injector is too large and it is difficult to achieve high-resolution regulation of small flow rates. Summary of the Invention

[0007] The purpose of the present invention is to provide a stepping motor-driven continuously adjustable micro-nozzle based on a hydraulic servo mechanism to solve the problems existing in the above-mentioned prior art.

[0008] To achieve the above purpose, the present invention provides a stepping motor-driven continuously adjustable micro-nozzle based on a hydraulic servo mechanism, including:

[0009] Valve body, an upper cavity, a middle cavity and a lower cavity are arranged inside the valve body, and the valve body comprises a lower valve body and an upper valve body; an oil injection hole is arranged on the side wall of the lower valve body, and the oil injection hole communicates with the middle cavity; an oil discharge hole is arranged on the side wall of the upper valve body, and the oil discharge hole communicates with the upper cavity; a circular nozzle hole is arranged at the bottom end of the lower valve body, and the circular nozzle hole communicates with the lower cavity;

[0010] Cone valve spool, the top end of the cone valve spool is arranged inside the upper cavity, and the side wall of the top end of the cone valve spool is in sliding fit with the inner wall of the upper cavity; the conical surface at the bottom of the cone valve spool and the lower cavity of the valve body cooperate to form a throttling surface for regulating the flow rate;

[0011] Control spool, a cylindrical hole is arranged at the top end of the cone valve spool, the bottom end of the control spool is inserted into the cylindrical hole and forms an inner wall hydraulic cavity; an oil return flow channel is arranged inside the control spool, and the oil return flow channel communicates with the oil discharge hole; two groups of communicating flow channels are arranged at the top of the cone valve spool, one group of the communicating flow channels is used for communicating the middle cavity with the upper cavity, and the other group of the communicating flow channels is used for communicating the upper cavity with the inner wall hydraulic cavity, and the port communicating with the middle cavity in the inner wall hydraulic cavity is located above the port communicating with the upper cavity;

[0012] Motor, the motor is installed at the top of the valve body, and the motor is used for driving the control spool to perform linear motion;

[0013] Connection accessory, the connection accessory is installed on the valve body and the motor.

[0014] Preferably, a baffle layer is arranged inside the lower valve body, and the baffle layer is located between the upper cavity and the middle cavity; a circular hole adapted to the cone valve spool is arranged in the middle of the baffle layer; a plurality of damping holes for communicating the upper cavity with the middle cavity are arranged on the baffle layer.

[0015] Preferably, the diameter of the circular nozzle hole is smaller than the diameter of the lower cavity, the diameter of the lower cavity is smaller than the diameter of the middle cavity, and the diameter of the middle cavity is the same as the diameter of the upper cavity.

[0016] Preferably, a circular flange is arranged at the bottom end of the upper valve body, a circular groove for embedding the circular flange is arranged at the top end of the lower valve body, and the diameter of the circular groove is larger than the diameter of the upper cavity.

[0017] Preferably, the cone valve spool consists of a cylindrical head, a cylindrical rod portion, a conical rod portion, and a conical portion. The cylindrical rod portion is adapted to the circular hole in the middle of the baffle layer, and the diameter of the cylindrical rod portion is greater than the diameter of the control spool. The communication flow channel is arranged in the cylindrical head. The diameter of the conical rod portion is not less than the diameter of the lower cavity section. The conical portion extends into the lower cavity section of the valve body, and the cone angle of the conical portion is not greater than 2°.

[0018] Preferably, a dynamic seal ring is sleeved on the top of the control spool. A seal ring groove is formed on the inner wall of the upper valve body, and the dynamic seal ring is installed in the seal ring groove.

[0019] Preferably, the control spool is composed of multiple sections of cylinders. A threaded hole is formed on the top surface of the cylinder at the uppermost part of the control spool, and the control spool is connected to the outer extension shaft of the motor through the threaded hole. The diameter of the cylinder at the lowermost part of the control spool is the same as the diameter of the cylindrical hole.

[0020] Preferably, the motor is an integrated stepping motor, and the control accuracy of the integrated stepping motor is not less than 0.006 mm.

[0021] Preferably, the oil injection hole and the oil discharge hole are arranged oppositely, and internal threads are processed on both the oil injection hole and the oil discharge hole.

[0022] Preferably, the lower valve body, the cone valve spool, the upper valve body, and the control spool are all made of metal materials, and the metal materials are cast iron, stainless steel, or alloy steel. The dynamic seal ring is made of non-metal materials or metal materials. The non-metal materials are rubber or polytetrafluoroethylene, and the metal materials are aluminum or copper.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] The continuously adjustable micro-nozzle driven by a stepping motor based on a hydraulic servo mechanism provided by the present invention drives the control spool to perform precise feeding and retracting linear motions through the high-precision micro-step adjustment ability of the motor, thereby opening different flow channels on the cone valve spool, and further forming a hydraulic pressure difference between the upper cavity section and the middle cavity section. Thereby, it promotes the cone valve spool to complete the follow-up of the movement of the control spool, achieving the purpose of changing the opening degree of the throttling surface formed by the cone valve spool and the lower cavity section of the valve body, so as to realize the high-precision adjustment and control of the flow rate of the medium flowing through the circular nozzle hole. In addition, the present invention can also continuously adjust the flow rate under complex working conditions where different fuel injection speeds are required, achieving the effects of small flow rate adjustment and continuous flow rate adjustment and control, and improving the fuel mixing and combustion efficiency in the combustion chamber of a ramjet engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0026] Figure 1 is an axonometric view of the stepping motor-driven continuously adjustable micro-nozzle based on a hydraulic follow-up mechanism of the present invention;

[0027] Figure 2 is Figure 1 the sectional axonometric view of the A-A section of;

[0028] Figure 3 is Figure 1 the sectional front view of the A-A section of;

[0029] Figure 4 is the axonometric view of the lower valve body;

[0030] Figure 5 is Figure 4 the sectional axonometric view of the B-B section of;

[0031] Figure 6 is the axonometric view of the cone valve spool;

[0032] Figure 7 is Figure 6 the sectional axonometric view of the C-C section and D-D section of;

[0033] Figure 8 is the axonometric view of the upper valve body;

[0034] Figure 9 is Figure 8 the sectional axonometric view of the E-E section of;

[0035] Figure 10 is the axonometric view of the control spool;

[0036] Figure 11 is Figure 10 the sectional axonometric view of the F-F section of;

[0037] Figure 12 is the axonometric view of the integrated stepping motor;

[0038] In the figure: 1. Lower valve body; 2. Cone valve spool; 3. Upper valve body; 4. Control spool; 5. Integrated stepping motor; 6. Connection accessory. Detailed implementation manners

[0039] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0040] As Figures 1 to 12 shown, the present invention provides a stepping motor-driven continuously adjustable micro-nozzle based on a hydraulic follow-up mechanism, including:

[0041] A valve body, with an upper cavity, a middle cavity and a lower cavity opened inside the valve body. The valve body includes a lower valve body 1 and an upper valve body 3; an oil injection hole is opened on the side wall of the lower valve body 1, and the oil injection hole communicates with the middle cavity; an oil discharge hole is opened on the side wall of the upper valve body 3, and the oil discharge hole communicates with the upper cavity; a circular nozzle hole is opened at the bottom end of the lower valve body 1, and the diameter of the circular nozzle hole is 0.3 - 0.5 mm to ensure good atomization characteristics, and the circular nozzle hole communicates with the lower cavity;

[0042] A conical valve spool 2, the top end of the conical valve spool 2 is arranged in the upper cavity, and the side wall of the top end of the conical valve spool 2 is slidably matched with the inner wall of the upper cavity; the conical surface at the bottom of the conical valve spool 2 cooperates with the lower cavity of the valve body to form a throttle surface for regulating the flow rate. By moving the conical valve spool 2 up and down, the size of the throttle surface can be changed, so as to realize continuous flow regulation;

[0043] A control spool 4, a cylindrical hole is opened at the top end of the conical valve spool 2, and the bottom end of the control spool 4 is inserted into the cylindrical hole to form an inner wall hydraulic cavity; an oil return flow channel is opened inside the control spool 4, and the oil return flow channel communicates with the oil discharge hole; two groups of communication channels are opened at the top of the conical valve spool 2. One group of communication channels is used to communicate the middle cavity with the upper cavity, and the other group of communication channels is used to communicate the upper cavity with the inner wall hydraulic cavity. And the port in the inner wall hydraulic cavity communicating with the middle cavity is located above the port communicating with the upper cavity to prevent the two groups of communication channels from opening simultaneously when the control spool 4 moves, which affects the hydraulic follow-up effect and further loses the accuracy of the nozzle during continuous flow regulation;

[0044] A motor, the motor is installed on the top of the valve body, and the motor is used to drive the control spool 4 to perform linear motion. The motor is an integrated stepping motor 5;

[0045] A connecting accessory 6, the connecting accessory 6 is installed on the valve body and the motor.

[0046] As Figure 3As shown, when the integrated stepper motor 5 drives and controls the control spool 4 to move downward, the communication flow passage connecting the middle cavity and the upper cavity on the left side of the poppet valve spool 2 opens, and high-pressure hydraulic oil enters the upper cavity. At this time, the pressures in the upper cavity and the middle cavity are balanced. However, since the force-receiving area at the upper end of the poppet valve spool 2 is larger than that at the lower end, the hydraulic pressure received at the upper end of the poppet valve spool 2 is greater than that at the lower end. The hydraulic pressure causes the poppet valve spool 2 to move downward until the left flow passage is completely closed. When the control spool 4 moves upward, the communication flow passage connecting the upper cavity and the inner wall hydraulic cavity on the right side opens, and the oil in the upper cavity flows back into the fuel tank, forming a low-pressure area. At this time, since the pressure in the lower cavity of the poppet valve spool 2 is higher than that in the upper cavity, the hydraulic pressure pushes the poppet valve spool 2 upward until the valve port is closed. In this way, the opening degree between the conical part of the poppet valve spool 2 and the lower cavity of the valve body is continuously changed to achieve continuous and precise regulation of the flow rate of the medium in the valve.

[0047] In a further optimized solution, a baffle layer is provided inside the lower valve body 1. The baffle layer is located between the upper cavity and the middle cavity. A circular hole adapted to the poppet valve spool 2 is provided in the middle of the baffle layer, so that the poppet valve spool 2 is coaxial with the nozzle hole. A plurality of damping holes for communicating the upper cavity and the middle cavity are provided on the baffle layer to prevent the pressure pulsation and pressure shock caused when filling the fluid medium from the oil inlet hole from affecting the hydraulic servo structure.

[0048] In a further optimized solution, the diameter of the circular nozzle hole is smaller than the diameter of the lower cavity, the diameter of the lower cavity is smaller than the diameter of the middle cavity, and the diameter of the middle cavity is the same as the diameter of the upper cavity.

[0049] In a further optimized solution, a circular flange is provided at the bottom end of the upper valve body 3, and a circular groove for embedding the circular flange is provided at the top end of the lower valve body 1. The diameter of the circular groove is larger than the diameter of the upper cavity, thereby improving the accuracy of the connection and positioning between the upper valve body 3 and the lower valve body 1 and the sealing performance of the fluid medium in the cavity.

[0050] In a further optimized solution, the poppet valve spool 2 is composed of a cylindrical head, a cylindrical rod portion, a conical rod portion, and a conical portion. The cylindrical rod portion is adapted to the circular hole in the middle of the baffle layer, and the diameter of the cylindrical rod portion is larger than the diameter of the control spool 4. The communication flow passage is arranged inside the cylindrical head. The diameter of the conical rod portion is not less than the diameter of the lower cavity to achieve the closure of the throttling surface. The conical portion extends into the lower cavity of the valve body, and the cone angle of the conical portion is not greater than 2° to ensure sufficient accuracy during the continuous flow rate adjustment of the nozzle.

[0051] In a further optimized solution, a dynamic sealing ring is sleeved on the top of the control spool 4, and a sealing ring groove is provided on the inner wall of the upper valve body 3. The dynamic sealing ring is installed in the sealing ring groove.

[0052] For a further optimized solution, the control valve spool 4 is composed of multiple cylindrical sections. A threaded hole is provided on the top surface of the cylindrical section at the uppermost part of the control valve spool 4, and the control valve spool 4 is connected to the extended shaft of the motor through the threaded hole; the diameter of the cylindrical section at the lowermost part of the control valve spool 4 is the same as the diameter of the cylindrical hole.

[0053] For a further optimized solution, the control precision of the integrated stepper motor 5 is not less than 0.006 mm.

[0054] For a further optimized solution, the oil injection hole and the oil drain hole are arranged opposite to each other, and internal threads are processed on both the oil injection hole and the oil drain hole.

[0055] For a further optimized solution, the lower valve body 1, the poppet valve spool 2, the upper valve body 3 and the control valve spool 4 are all made of metal materials, and the metal materials are cast iron, stainless steel or alloy steel; the dynamic sealing ring is made of non-metal materials or metal materials, the non-metal materials are rubber or polytetrafluoroethylene, and the metal materials are aluminum or copper.

[0056] For a further optimized solution, the outer shapes of the lower valve body 1 and the upper valve body 3 are both cube-shaped. Bolt through holes are provided at the four corners of the cube of the lower valve body 1, the upper valve body 3 and the integrated stepper motor 5. The bolt through holes at the corresponding four corners of the three components need to have the same diameter and be coaxial, and are connected and fixed together using the bolts of the connecting accessory 6.

[0057] For a further optimized solution, the number of two groups of communicating flow channels in the cylindrical head of the poppet valve spool 2 is the same. The number of each group of communicating flow channels is increased and is circularly arrayed with the center of the upper end face of the poppet valve spool 2 as the center, so that the distance between each communicating flow channel is 45°. In this way, the flow-through area can be increased and the hydraulic response speed can be improved.

[0058] The stepper motor-driven continuously adjustable micro-nozzle based on the hydraulic servo mechanism provided by the present invention combines the advantages of motor drive and hydraulic control. By driving and controlling the valve spool by the motor, the opening degree of the conical throttling surface is accurately changed by the hydraulic servo structure, which can achieve high-precision fuel injection and has the advantages of continuous adjustability, fast response, high stability and energy saving. It is applicable to the scenario of micro-flow high-precision control, and can be used in industrial occasions such as efficient fuel injection in the combustion chamber of aero-engines, precision drip irrigation and chemical reagent transportation, and can achieve high-precision flow regulation in a small flow range.

[0059] The above is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A stepping motor-driven continuously adjustable micro-nozzle based on a hydraulic servo mechanism, characterized in that, Comprising: A valve body, an upper cavity, a middle cavity and a lower cavity are formed inside the valve body. The valve body includes a lower valve body (1) and an upper valve body (3); an oil injection hole is formed in the side wall of the lower valve body (1), and the oil injection hole communicates with the middle cavity; an oil discharge hole is formed in the side wall of the upper valve body (3), and the oil discharge hole communicates with the upper cavity; a circular nozzle hole is formed at the bottom end of the lower valve body (1), and the circular nozzle hole communicates with the lower cavity. A poppet valve spool (2), the top end of the poppet valve spool (2) is arranged in the upper cavity, and the side wall of the top end of the poppet valve spool (2) is slidably matched with the inner wall of the upper cavity; the conical surface at the bottom of the poppet valve spool (2) and the lower cavity of the valve body cooperate to form a throttling surface for regulating the flow rate. A control spool (4), a cylindrical hole is formed at the top end of the poppet valve spool (2), and the bottom end of the control spool (4) is inserted into the cylindrical hole to form an inner wall hydraulic cavity; an oil return flow channel is formed inside the control spool (4), and the oil return flow channel communicates with the oil discharge hole; two groups of communication channels are formed at the top of the poppet valve spool (2), one group of the communication channels is used to communicate the middle cavity with the upper cavity, and the other group of the communication channels is used to communicate the upper cavity with the inner wall hydraulic cavity, and the port in the inner wall hydraulic cavity communicating with the middle cavity is located above the port communicating with the upper cavity. A motor, the motor is installed on the top of the valve body, and the motor is used to drive the control spool (4) to perform a linear motion. A connecting accessory (6), the connecting accessory (6) is installed on the valve body and the motor.

2. The continuously adjustable micro-nozzle driven by a stepping motor based on a hydraulic servo mechanism according to claim 1, wherein A baffle layer is arranged inside the lower valve body (1), and the baffle layer is located between the upper cavity and the middle cavity; a circular hole adapted to the poppet valve spool (2) is formed in the middle of the baffle layer; a plurality of damping holes for communicating the upper cavity with the middle cavity are formed in the baffle layer.

3. The continuously adjustable micro-nozzle driven by a stepping motor based on a hydraulic servo mechanism according to claim 1, characterized in that The diameter of the circular nozzle hole is smaller than the diameter of the lower cavity, the diameter of the lower cavity is smaller than the diameter of the middle cavity, and the diameter of the middle cavity is the same as the diameter of the upper cavity.

4. The continuously adjustable micro-nozzle driven by a stepper motor based on a hydraulic servo mechanism according to claim 3, wherein A circular flange is arranged at the bottom end of the upper valve body (3), and a circular groove for embedding the circular flange is formed at the top end of the lower valve body (1), and the diameter of the circular groove is larger than the diameter of the upper cavity.

5. The continuously adjustable micro-nozzle driven by a stepping motor based on a hydraulic servo mechanism according to claim 2, characterized in that The poppet valve spool (2) is composed of a cylindrical head, a cylindrical rod part, a conical rod part and a conical part. The cylindrical rod part is adapted to the circular hole in the middle of the baffle layer, and the diameter of the cylindrical rod part is larger than the diameter of the control spool (4); the communication channels are arranged in the cylindrical head, the diameter of the conical rod part is not less than the diameter of the lower cavity, the conical part extends into the lower cavity of the valve body, and the cone angle of the conical part is not greater than 2°.

6. The continuously adjustable micro-nozzle driven by a stepper motor based on a hydraulic servo mechanism according to claim 1, wherein A dynamic seal ring is sleeved on the top of the control spool (4), and a seal ring groove is formed on the inner wall of the upper valve body (3), and the dynamic seal ring is installed in the seal ring groove.

7. The continuously adjustable micro-nozzle driven by a stepper motor based on a hydraulic servo mechanism according to claim 1, wherein The control spool (4) consists of multiple cylindrical sections. A threaded hole is provided on the top surface of the cylinder at the uppermost part of the control spool (4), and the control spool (4) is connected to the extension shaft of the motor through the threaded hole; the diameter of the cylinder at the lowermost part of the control spool (4) is the same as the diameter of the cylindrical hole.

8. The continuously adjustable micro-nozzle driven by a stepper motor based on a hydraulic servo mechanism according to claim 1, characterized in that, The motor is an integrated stepping motor (5), and the control precision of the integrated stepping motor (5) is not less than 0.006 mm.

9. The continuously adjustable micro-nozzle driven by a stepping motor based on a hydraulic servo mechanism according to claim 1, characterized in that, The oil injection hole and the oil drain hole are arranged oppositely, and internal threads are machined on both the oil injection hole and the oil drain hole.

10. The continuously adjustable micro-nozzle driven by a stepper motor based on a hydraulic servo mechanism according to claim 6, characterized in that, The lower valve body (1), the cone valve spool (2), the upper valve body (3) and the control spool (4) are all made of metal materials, and the metal materials are cast iron, stainless steel or alloy steel; the dynamic sealing ring is made of non-metallic materials or metal materials, the non-metallic materials are rubber or polytetrafluoroethylene, and the metal materials are aluminum or copper.

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