Superimposed adjustable differential pressure reducing valve

Abstract

The application discloses a superimposed adjustable differential pressure reducing valve, aiming at solving the problems of the existing fixed differential pressure reducing valve, such as non-adjustable pressure difference, poor dynamic and static performance matching, and limited application scenarios. The reducing valve comprises a valve body, a pressure stabilizing and adjusting assembly arranged in the valve body, a sliding valve spool, a throttling assembly, a pressure compensation spring and a shuttle valve assembly; the pressure stabilizing and adjusting assembly adjusts the pre-tightening force of the pressure compensation spring through a pressure stabilizing valve spool in threaded cooperation with a sliding valve sleeve, realizes continuous adjustment of the pressure difference, and locks the position after adjustment through a locking nut; the throttling hole of the throttling assembly and the damping hole of the shuttle valve feedback loop are both matched through simulation optimization, and the shuttle valve assembly is compatible with bidirectional load port pressure feedback and external pressure regulating port control pressure input. The application realizes a pressure difference adjustment range of 0.5-1.5 MPa, and the maximum flow rate reaches 61.74 L / min, while high-precision fixed-difference control and high operation stability are taken into account, and the application can be widely applied to hydraulic control systems in the fields of aerospace, automobiles, engineering machinery and the like.

Description

Technical Field

[0001] This invention relates to the field of pressure reducing valve technology, and in particular to a superimposed adjustable differential pressure reducing valve. Background Technology

[0002] Pressure reducing valves are widely used pressure control valves in the fluid transmission field. They are mainly used to maintain a stable pressure difference between the supply port pressure and the load port pressure. Pressure reducing valves are widely used in industries such as aerospace, automotive, shipbuilding, and construction machinery. Their performance directly affects the performance of pressure control systems, providing strong guarantees for the reliability, safety, and stability of the systems.

[0003] The invention patent with publication number CN119321498A (hereinafter referred to as prior art 1) discloses a superimposed differential pressure reducing valve. This solution makes the valve suitable for high flow conditions by setting a large-diameter oil supply channel; by setting a damping structure on the valve core, the control accuracy and operating stability of the pressure reducing valve under high pressure conditions are improved, providing a feasible technical solution for the technological development of high pressure and high flow pressure reducing valves.

[0004] In practical engineering applications, it was found that this solution still has room for optimization: First, the solution is a fixed differential structure, with the differential pressure fixed by the pre-compression of the return spring, which cannot be continuously adjusted according to the control requirements of different working conditions, thus limiting its adaptability to hydraulic systems in multiple scenarios; Second, its damping structure and throttling structure are not precisely parameterized and matched, making it difficult to simultaneously ensure the static control accuracy and dynamic response performance of the valve components; Third, its shuttle valve assembly only supports pressure feedback from two load ports and does not support the access of external control pressure, which cannot meet the usage requirements of special working conditions such as remote pressure regulation and multi-system linkage.

[0005] Therefore, achieving continuous adjustable differential pressure, while simultaneously optimizing the parameters of the damping orifice and throttling orifice to balance the control accuracy, response speed, and operational stability of the valve, and expanding the applicable operating conditions of the product, are urgent technical problems to be solved.

[0006] It should be noted that the above technical information is the result of the applicant's inventive analysis. This explanation is only intended to enhance the understanding of the general background technology of this application by those skilled in the art, and should not be regarded as an admission or implication in any form that the following technical information constitutes prior art known to those skilled in the art. Summary of the Invention

[0007] To address the shortcomings in the aforementioned background technology, this invention proposes a superimposed adjustable differential pressure reducing valve. The technical problem to be solved is: how to achieve continuous adjustable differential pressure, while simultaneously optimizing the parameters of the damping orifice and the throttling orifice to balance the control accuracy, response speed, and operational stability of the valve, and expand the applicable operating conditions of the product.

[0008] The technical solution of this invention is as follows:

[0009] Core technical solution: A superimposed adjustable differential pressure reducing valve, including a valve body, wherein the valve body is provided with a pressure inlet P in, a pressure outlet P out, a first load port A and a second load port B, the valve body is provided with a spool valve core as a pressure sensitive element, a pressure compensation spring and a shuttle valve assembly, the two oil inlets of the shuttle valve assembly are respectively connected to the first load port A and the second load port B, and also includes a pressure regulating component;

[0010] The pressure regulating assembly includes a pressure regulating valve core, a spool valve sleeve, and a locking nut. The spool valve sleeve is fixedly installed in the valve body. The pressure regulating valve core is threadedly connected to the spool valve sleeve. The two ends of the pressure compensation spring abut against the pressure regulating valve core and the spool valve core, respectively. Rotating the pressure regulating valve core can adjust its relative displacement with the spool valve sleeve to change the preload of the pressure compensation spring. The locking nut is sleeved on the outer circumference of the pressure regulating valve core and is used to lock the relative position of the pressure regulating valve core and the spool valve sleeve after adjustment.

[0011] The spool valve core is slidably disposed within the spool valve sleeve. The spool valve core cooperates with the throttling valve core fixed in the valve body to form a throttling assembly. The throttling valve core has at least two throttling holes circumferentially opened on it. The axial movement of the spool valve core can change the flow area of ​​the throttling holes to achieve the regulation of outlet pressure and flow rate.

[0012] The oil outlet of the shuttle valve assembly is connected to the spring cavity where the pressure compensation spring is located through a damping hole, and the spring cavity is connected to the pressure outlet P. The shuttle valve assembly is also provided with a control flow channel connected to the external pressure regulating port Y, which is used to connect to an external control pressure higher than the pressure of the first load port A and the second load port B, so as to achieve constant differential regulation.

[0013] The beneficial effects of the above core technical solutions are as follows:

[0014] The innovative threaded adjustment pressure regulating component allows for continuous adjustment of the preload of the pressure compensation spring by rotating the pressure regulating valve core, enabling flexible adjustment of the pressure differential of the pressure reducing valve and adapting to the differential control requirements of different working conditions. After adjustment, the position is locked by tightening the lock nut to ensure the long-term stability of the pressure differential setting value, thus solving the problems of fixed pressure differential and insufficient adaptability of traditional differential pressure reducing valves.

[0015] The division of labor among the three core functional components of the pressure reducing valve is clearly defined: the spool valve core serves as the sensing element to detect the load pressure and its changes, driving the spool valve core to move axially; the pressure compensation spring serves as the reference load element to determine the differential pressure adjustment value and support online adjustment; and the throttling assembly composed of the spool valve core and the throttling valve core serves as the regulating element, achieving precise adjustment of outlet pressure and flow rate by changing the throttling area. The three components work together to ensure the stability and accuracy of differential control, making the flow rate through the actuator independent of the load pressure.

[0016] The shuttle valve assembly is compatible with bidirectional load pressure feedback from the first load port A and the second load port B, as well as external control pressure input from the external pressure regulating port Y. It can automatically select the highest pressure for feedback, which is suitable for the normal working conditions of bidirectional actuators and can also meet the special needs of remote pressure regulation and multi-system linkage, greatly expanding the applicable scenarios of the product.

[0017] The damping orifice is located between the oil outlet of the shuttle valve and the spring cavity, which can effectively buffer load pressure fluctuations and suppress valve core vibration, providing a core guarantee for the stable operation of the valve.

[0018] Based on the above technical solutions, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the differential pressure adjustment range of the pressure compensation spring is 0.5-1.5MPa.

[0019] Further beneficial effects of this technical solution are: it clarifies the optimal pressure adjustment range of the pressure compensation spring, which can cover the constant differential control requirements of conventional hydraulic systems from 0.5 to 1.5 MPa; the spring stiffness and adjustment stroke are well matched; the adjustment linearity is good; and the control accuracy is high.

[0020] Based on the above technical solution, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the number of throttling orifices is 4, the 4 throttling orifices are evenly distributed along the circumference of the throttling valve core, the diameter of the throttling orifice is 3.2mm, and the initial coverage of the spool valve core relative to the throttling orifice is 2.34mm.

[0021] Further beneficial effects of this technical solution are as follows: The throttling orifice parameters verified by AMEsim simulation, and the 4-hole circumferentially evenly distributed structure can ensure uniform force on the spool valve core and avoid movement jamming; the matching design of 3.2mm orifice diameter and 2.34mm initial cover can maintain stable load pressure difference and flow rate during operation. According to the test, under this parameter, when the load inlet pressure is 1.1MPa, the load flow rate can be stabilized at 41.3L / min, while effectively reducing the risk of throttling orifice blockage and improving the valve's anti-pollution ability and service life.

[0022] Based on the above technical solutions, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the diameter of the damping orifice is 0.4 mm and the length is 0.38 mm.

[0023] Further beneficial effects of this technical solution are as follows: The damping orifice parameter, verified by AMEsim simulation and repeated experiments, perfectly balances the static control accuracy and dynamic response performance of the valve. It avoids insufficient damping, large internal leakage, and large opening and closing errors caused by excessively large or short damping orifice size, and also avoids slow valve core response, large pressure overshoot, and easy blockage caused by excessively small or long damping orifice size. According to the test, the flow rate of the pressure reducing valve can be stabilized at 49.35 L / min under this parameter, and the inlet pressure fluctuation can be controlled within 1.568 MPa, demonstrating excellent synergy between dynamic and static performance.

[0024] Based on the above technical solutions, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the shuttle valve assembly includes a shuttle valve body, a shuttle valve sleeve, and a steel ball. The shuttle valve sleeve is fixedly installed in the shuttle valve body, and the steel ball is movably disposed in the inner cavity of the shuttle valve sleeve, for selecting the highest pressure among the first load port A, the second load port B, and the external pressure regulating port Y to be introduced into the damping orifice.

[0025] Further beneficial effects of this technical solution are: the steel ball shuttle valve has a fast response speed and good sealing performance, and can realize seamless switching between two load pressures and one external control pressure, ensuring the timeliness and accuracy of the highest pressure feedback, and further improving the accuracy of differential control.

[0026] Based on the above technical solutions, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, O-rings are provided between the spool valve sleeve and the valve body, between the pressure regulating valve core and the spool valve sleeve, between the spool valve core and the spool valve sleeve, and between the shuttle valve body and the valve body. A sealing retainer is also provided between the mating surfaces of the spool valve core and the spool valve sleeve.

[0027] Further beneficial effects of this technical solution are: the layered design of the multi-seal structure can effectively eliminate internal and external leakage of valve components, ensure the stability of pressure control, and adapt to the use requirements of high-pressure conditions, thereby improving the safety performance and service life of valve components.

[0028] Based on the above technical solutions, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the main flow channel of the valve body is a high-flow-rate, low-pressure-loss flow channel optimized by CFD simulation, and the maximum flow rate of the pressure reducing valve is 61.74 L / min.

[0029] Further beneficial effects of this technical solution are as follows: The high-flow-rate, low-pressure-loss flow channel, optimized through CFD simulation iteration, determines the optimal channel size parameters by calculating and optimizing the flow field distribution of the main channel and auxiliary channels under different pressures and flow rates, achieving a maximum flow rate of 61.74 L / min, which can meet the usage requirements of high-flow-rate hydraulic systems and expand the application range of the product.

[0030] Based on the above technical solution, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the end of the pressure stabilizing valve core facing the pressure compensation spring is provided with a spring seat one, and the end of the slide valve core facing the pressure compensation spring is provided with a spring seat two. The two ends of the pressure compensation spring are respectively limited and installed in the spring seat one and the spring seat two by spring washers.

[0031] Further beneficial effects of this technical solution are: the design of double spring seats with spring washers can reliably limit the radial and axial movement of the pressure compensation spring, avoid the spring from shifting or becoming unstable during operation, ensure the linear output of the spring force, and improve the accuracy and repeatability of differential pressure regulation.

[0032] Based on the above technical solutions, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the internal thread of the locking nut is matched with the external thread of the pressure regulating valve core. In the locked state, the end face of the locking nut is in close contact with the end face of the slide valve sleeve; the end of the pressure regulating valve core is also provided with a steel wire retaining ring for preventing the locking nut from coming out.

[0033] Further beneficial effects of this technical solution are: the end-face contact locking structure ensures reliable locking and effectively prevents the pressure regulating valve core from loosening due to vibration during operation, thus ensuring the long-term stability of the differential pressure setting value; the steel wire retaining ring can limit the lock nut from coming out, preventing parts loss and improving the convenience of valve maintenance.

[0034] Based on the above technical solutions, as a preferred technical solution for the superimposed adjustable differential pressure reducing valve, the throttle valve core is fixedly installed in the slide valve sleeve by a retaining ring, and the end of the shuttle valve body is provided with a plug for blocking the process flow channel.

[0035] Further beneficial effects of this technical solution are: the throttling valve core fixed by the retaining ring is installed stably, which can ensure the fitting accuracy with the slide valve core; the plug structure can block the process flow channel, which not only facilitates the processing and manufacturing of the valve body flow channel, but also facilitates subsequent maintenance and cleaning.

[0036] The overall beneficial effects of this invention are as follows: The superimposed adjustable differential pressure reducing valve provided by this invention breaks through the structural limitations of traditional constant differential pressure reducing valves, realizes continuous online adjustment of differential pressure, and greatly improves the product's adaptability to different working conditions; the flow channel, damping orifice, and throttling orifice structures optimized by CFD and AMEsim multiphysics simulation simultaneously take into account large flow capacity, high-precision constant differential control, and high-stability operation; the integrated multi-functional shuttle valve assembly is compatible with bidirectional load feedback and remote pressure regulation, and can be widely used in hydraulic control systems in aerospace, automotive, shipbuilding, and engineering machinery fields, possessing strong engineering application value and market promotion prospects. Attached Figure Description

[0037] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a cross-sectional view of the overall structure of the superimposed adjustable differential pressure reducing valve described in this invention;

[0039] Figure 2 This is a perspective view of the superimposed adjustable differential pressure reducing valve described in this invention;

[0040] Figure 3 This is a schematic diagram of the damping orifice described in this invention;

[0041] Figure 4 This is a schematic diagram of the throttling orifice described in this invention;

[0042] Figure 5 This is a CFD simulation analysis cloud diagram of the main flow channel of the pressure reducing valve described in this invention;

[0043] Figure 6 The flow-pressure simulation characteristic curve of the damping orifice design described in this invention is shown.

[0044] Figure 7 The flow-pressure simulation characteristic curve of the orifice design described in this invention is shown.

[0045] Figure 8 This is a schematic diagram of the hydraulic circuit of the superimposed adjustable differential pressure reducing valve described in this invention.

[0046] Explanation of icon numbers:

[0047] 1-Pressure stabilizing valve core, 2-Steel wire retaining ring, 3-Locking nut, 4-Slide valve sleeve, 5-First O-ring, 6-Spring seat one, 7-Pressure compensation spring, 8-Spring washer, 9-Retaining ring, 10-Second O-ring, 11-Third O-ring, 12-Sealing retaining ring, 13-Throttle valve core, 14-Slide valve core, 15-Spring seat two, 16-Fourth O-ring, 17-Fifth O-ring, 18-Plug, 19-Sixth O-ring, 20-Shuttle valve body, 21-Seventh O-ring, 22-Steel ball, 23-Shuttle valve sleeve, 24-Eighth O-ring, P in - Pressure inlet, P out - Pressure outlet, A-First load port, B-Second load port, T-Return oil port, Y-External pressure regulating port. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the core concept of the present invention and the following embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​illustrated in these embodiments should be interpreted as merely exemplary and not as limiting.

[0050] It should be noted that, in the description of this application, unless otherwise stated, "several" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "axial," "radial," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0051] Furthermore, the terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well.

[0052] It should also be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0053] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0054] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0055] General Implementation Examples

[0056] This embodiment discloses a superimposed adjustable differential pressure reducing valve, such as... Figure 1 , Figure 2 and Figure 8 As shown, the valve body includes a pressure inlet Pin, a pressure outlet Pout, a first load port A, a second load port B, a return port T, and an external pressure regulating port Y. From left to right, the valve body contains a pressure regulating component, a spool valve component, a throttling component, and a shuttle valve component, which are coaxially arranged. The whole structure adopts a stacked structure design and can be stacked with hydraulic valves such as proportional directional valves and relief valves to meet the integration requirements of standardized hydraulic systems.

[0057] 1. Structure and assembly relationship of each component

[0058] The core components of the pressure reducing valve in this embodiment include: a pressure regulating valve core 1, a wire retaining ring 2, a locking nut 3, a spool valve sleeve 4, a first O-ring 5, a second O-ring 10, a third O-ring 11, a fourth O-ring 16, a fifth O-ring 17, a sixth O-ring 19, a seventh O-ring 21, an eighth O-ring 24, a spring seat 1 6, a pressure compensation spring 7, a spring washer 8, a retaining ring 9, a sealing retaining ring 12, a throttle valve core 13, a spool valve core 14, a second spring seat 15, a plug 18, a shuttle valve body 20, a steel ball 22, and a shuttle valve sleeve 23. The assembly relationship of each part is as follows:

[0059] Pressure regulating component: The spool valve sleeve 4 is fixedly installed in the central mounting hole of the valve body by interference fit. The inner wall of the left end of the spool valve sleeve 4 is provided with internal thread, and the outer wall of the right end of the pressure regulating valve core 1 is provided with matching external thread. The pressure regulating valve core 1 and the spool valve sleeve 4 are coaxially connected by threads. Rotating the pressure regulating valve core 1 can precisely adjust its axial displacement relative to the spool valve sleeve 4. A spring mounting groove is opened on the right end face of the pressure regulating valve core 1. The spring seat 1 6 and the spring washer 8 are installed in the mounting groove in sequence. The left end of the pressure compensation spring 7 abuts against the spring washer 8, and the right end of the pressure compensation spring 7 abuts against the left end face of the spool valve core 14 through the spring seat 2 15. In this embodiment, the differential pressure adjustment range of the pressure compensation spring 7 is 0.5-1.5MPa. By rotating the pressure regulating valve core 1 to change the pre-compression of the spring, the set differential pressure of the pressure reducing valve can be continuously adjusted. The locking nut 3 is fitted onto the outer circumference of the left end of the pressure regulating valve core 1. The internal thread of the locking nut 3 mates with the external thread of the pressure regulating valve core 1. After the differential pressure adjustment is completed, tightening the locking nut 3 so that its right end face tightly abuts against the left end face of the spool valve sleeve 4 locks the axial position of the pressure regulating valve core 1, preventing the differential pressure setting value from shifting. The wire retaining ring 2 is fitted into the annular groove at the left end of the pressure regulating valve core 1 to prevent the locking nut 3 from coming out and to avoid loss of parts.

[0060] Spool valve assembly: The spool valve core 14 is coaxially slidably disposed in the inner hole of the right end of the spool valve sleeve 4. The fitting clearance between the spool valve core 14 and the spool valve sleeve 4 is 0.008-0.012mm, ensuring smooth sliding of the valve core without excessive internal leakage. The spool valve core 14 is the pressure-sensitive element of the pressure reducing valve, used to sense changes in load pressure and generate axial displacement, realizing closed-loop adjustment of the throttling flow area.

[0061] Sealing structure: The outer wall of the slide valve sleeve 4 is provided with multiple annular grooves along the axial direction. The first O-ring 5, the second O-ring 10, the third O-ring 11, the fourth O-ring 16, and the fifth O-ring 17 are respectively installed in the annular grooves to achieve static sealing between the slide valve sleeve 4 and the valve body; an O-ring is provided between the mating surface of the pressure stabilizing valve core 1 and the slide valve sleeve 4 to achieve dynamic sealing during reciprocating motion; a sixth O-ring and a sealing retainer 12 are provided between the mating surface of the slide valve core 14 and the slide valve sleeve 4 to achieve dynamic sealing and prevent internal leakage; a seventh O-ring 21 and an eighth O-ring 24 are provided between the mating surface of the shuttle valve body 20 and the valve body to achieve static sealing; a plug 18 is provided at the end of the shuttle valve body 20, and a sixth O-ring 19 is provided between the plug 18 and the shuttle valve body 20 to block the process flow channel and facilitate processing and maintenance.

[0062] Throttling assembly: includes a throttling valve core 13 and a spool valve core 14. The throttling valve core 13 is fixedly installed in the inner hole of the right end of the spool valve sleeve 4 by a retaining ring 9, located on the right side of the spool valve core 14. The throttling valve core 13 and the spool valve sleeve 4 are interference-fitted to ensure the stability of the installation position. Four throttling orifices are evenly opened circumferentially on the throttling valve core 13, with a diameter of 3.2mm. The initial coverage of the right end face of the spool valve core 14 relative to the throttling orifice is 2.34mm. When the spool valve core 14 moves left and right along the axial direction, the flow area of ​​the throttling orifice can be changed, thereby achieving precise regulation of the outlet pressure and flow rate.

[0063] The shuttle valve assembly includes a shuttle valve body 20, a shuttle valve sleeve 23, and a steel ball 22. The shuttle valve body 20 is fixedly mounted on the right end of the valve body using hexagonal socket screws. The shuttle valve sleeve 23 is interference-fitted into the inner bore of the shuttle valve body 20. The steel ball 22 is movably disposed within the inner cavity of the shuttle valve sleeve 23, with its diameter clearance fitting to the inner bore of the shuttle valve sleeve 23 to ensure smooth rolling and reliable sealing. The shuttle valve body 20 has two oil inlets, which are connected to the first load port A and the second load port B respectively through flow channels inside the valve body. The shuttle valve body 20 also has a control flow channel, which is connected to the external pressure regulating port Y for connecting to external control pressure. The right end of the shuttle valve sleeve 23 is provided with an oil outlet. The oil outlet is connected to the spring cavity where the pressure compensation spring 7 is located through a damping hole. The spring cavity is connected to the pressure outlet P through the flow channel inside the valve body. In this embodiment, the damping hole is opened on the flow channel between the shuttle valve oil outlet and the spring cavity. The diameter of the damping hole is dr=0.4mm and the length is lr=0.38mm.

[0064] Flow channel design: The main flow channel of the valve body is a high-flow-rate, low-pressure-loss flow channel optimized by CFD simulation. By calculating and iteratively optimizing the flow field distribution of the main flow channel and auxiliary flow channel of the pressure reducing valve under different pressures and flow rates, the relevant dimensional parameters of each flow channel of the pressure reducing valve were determined. Based on the parameters, each flow channel of the pressure reducing valve was manufactured and processed. Finally, through flow capacity testing, the maximum flow capacity of the pressure reducing valve of 61.74 L / min was achieved.

[0065] 2. Core Design Simulation Verification

[0066] Damping orifice simulation optimization: AMEsim simulation analysis clearly shows that the size and length of the damping orifice directly affect the valve's dynamic and static performance. An orifice that is too large or too short will result in insufficient damping, large internal leakage, and large opening and closing errors, affecting the valve's static performance. An orifice that is too small or too long will result in slower valve core response time, large pressure overshoot, and is also prone to clogging, affecting the valve's dynamic performance. Based on hydraulic pressure empirical values ​​and repeated simulation calculations, such as... Figure 1 and Figure 3 As shown, the optimal parameters for the damping orifice were finally determined to be 0.4 mm in diameter and 0.38 mm in length. Simulation verification confirmed this. Figure 6 As shown, under these parameters, the flow rate of the pressure reducing valve can be stabilized at 49.35 L / min, and the inlet pressure can be stabilized at 1.568 MPa, achieving an optimal balance between dynamic and static performance.

[0067] Orifice Simulation Optimization: AMEsim simulation analysis clearly shows that the size, number, and initial coverage area of ​​the orifices directly affect the load differential pressure and flow control effect of the pressure reducing valve. Through multiple rounds of simulation iterations, such as... Figure 1 and Figure 4 As shown, the optimal parameters were finally determined to be 4 throttling orifices with a diameter of 3.2 mm and an initial coverage of 2.34 mm. Simulation verification confirmed this. Figure 7 As shown, under these parameters, when the load inlet pressure is 1.1 MPa, the load flow rate can be stabilized at 41.3 L / min, demonstrating excellent constant-difference control accuracy.

[0068] 3. Working Principle

[0069] The hydraulic principle of the superimposed adjustable differential pressure reducing valve in this embodiment is as follows: Figure 8 As shown, the core working principle is as follows:

[0070] Differential pressure setting steps: Rotate the pressure regulating valve core 1 and adjust its axial position through threaded transmission to change the pre-compression of the pressure compensation spring 7, thereby setting the target differential pressure of the pressure reducing valve; after adjustment, tighten the locking nut 3 to lock the position of the pressure regulating valve core 1 and ensure the stability of the differential pressure setting value.

[0071] Forward load differential control (right end of proportional directional valve energized): Hydraulic medium enters the valve from pressure inlet P, flows through the main channel of spool valve sleeve 4 and the throttling orifice of the throttling component, and then flows out from pressure outlet P. It then flows through the proportional directional valve to the first load port A, driving the actuator to move forward. At this time, the pressure oil at the first load port A is divided into two paths: one path enters the actuator to drive the load, and the other path enters the left inlet of the shuttle valve assembly through the internal flow channel of the valve body, pushing the steel ball 22 to move to the right, blocking the control flow channel between the right inlet and the external pressure regulating port Y; the pressure oil at port A enters the spring chamber through the shuttle valve outlet and damping orifice, and then flows back to pressure outlet P through the flow channel. At this time, the difference between the pressure at pressure outlet P and the pressure in the spring chamber (i.e., the load pressure at port A) is balanced by the spring force of the pressure compensation spring 7. When the load pressure at port A increases, the pressure in the spring chamber increases synchronously, pushing the spool valve core 14 to the left, reducing the flow area of ​​the throttling orifice, and causing the pressure at pressure outlet P to decrease until the pressure difference between P and port A returns to the set value. When the load pressure at port A decreases, the pressure in the spring chamber decreases synchronously, and the pressure compensation spring 7 pushes the spool valve core 14 to the right, increasing the flow area of ​​the throttling orifice, and causing the pressure at pressure outlet P to increase until the pressure difference returns to the set value. This achieves constant pressure difference control between P and port A, ensuring that the flow rate through the proportional directional valve is independent of the load pressure, and achieving stable flow control.

[0072] Reverse load differential control (proportional directional valve energized on the left): Hydraulic medium flows in from pressure inlet P, out through pressure outlet P, and through the proportional directional valve to the second load port B, driving the actuator to reverse. At this time, the pressure oil at port B enters the right inlet of the shuttle valve assembly through the valve body flow channel, pushing the steel ball 22 to the left, blocking the control flow channel between the left inlet and the external pressure regulating port Y; the pressure oil at port B enters the spring chamber through the shuttle valve outlet and damping orifice, and the pressure reducing valve will automatically maintain the pressure difference between the pressure outlet P and port B at the set value, realizing the differential control of reverse load, adapting to the usage requirements of bidirectional actuators.

[0073] External pressure regulation differential control: When the control pressure connected to the external pressure regulating port Y is higher than the load pressure of ports A and B, the external control pressure will push the steel ball 22 to block the oil inlet of the load port on both sides. The external control pressure enters the spring chamber through the damping hole. The pressure reducing valve will automatically maintain the pressure difference between the pressure outlet P and the external control pressure at the set value, realizing differential regulation for special working conditions such as remote pressure regulation and multi-system linkage control.

[0074] 4. Performance parameters

[0075] The core performance parameters of the pressure reducing valve in this embodiment are as follows:

[0076] Rated working pressure: 31.5 MPa;

[0077] Maximum flow rate: 61.74 L / min;

[0078] Differential pressure adjustment range: 0.5-1.5MPa;

[0079] Differential pressure control accuracy: ≤±0.05MPa;

[0080] Pressure overshoot: ≤5%;

[0081] Response time: ≤15ms;

[0082] Applicable medium: Hydraulic oil (ISO VG46);

[0083] Operating temperature: -40℃ to 120℃.

[0084] Example 1

[0085] The difference between this sub-example and the general example is that the throttle valve core 13 has two throttle orifices, which are symmetrically distributed circumferentially along the throttle valve core. The diameter of the throttle orifices is 4mm, and the initial coverage of the spool valve core 14 relative to the throttle orifices is 2mm. The throttle orifice parameters of this sub-example are suitable for small to medium flow conditions, with a flow rate up to 30L / min, which can meet the constant-differential control requirements of small hydraulic systems and precision control circuits. The remaining structure, assembly relationship, working principle, and performance testing methods are consistent with the general example.

[0086] Example 2

[0087] The difference between this embodiment and the general embodiment is that the damping orifice is located inside the spool valve core 14, with both ends connected to the spring cavity and the pressure outlet P, respectively. The diameter of the damping orifice is 0.35 mm and its length is 0.4 mm. This damping orifice configuration further enhances the damping effect of the spool valve core movement, suppresses high-frequency vibration of the valve core, reduces pressure shock, and improves the operational stability of the pressure reducing valve under conditions of sudden high-pressure changes and frequent load reversals. The remaining structure, assembly relationships, and working principles are consistent with the general embodiment.

[0088] Example 3

[0089] The difference between this embodiment and the general embodiment is that the pressure compensation spring 7 has a wire diameter of 1.5mm, an effective number of coils of 10, and a differential pressure adjustment range of 1-2MPa. It is suitable for the constant differential control requirements under high differential pressure conditions and can be adapted to the application scenarios of high pressure heavy-duty hydraulic systems. The rest of the structure, assembly relationship, and working principle are the same as those in the general embodiment.

[0090] Example 4

[0091] The difference between this embodiment and the general embodiment is that the main flow channel of the valve body has been further optimized by CFD simulation, the flow channel diameter has been increased, the rounded transition at the bend of the flow channel has been optimized, and the local resistance coefficient of the flow channel has been reduced. The maximum flow rate of the pressure reducing valve can reach 80L / min, which is suitable for the hydraulic system conditions of engineering machinery and metallurgical equipment with ultra-large flow. The rest of the structure, assembly relationship and working principle are the same as those of the general embodiment.

[0092] All aspects not detailed in this invention are conventional technical means known to those skilled in the art.

[0093] The above content shows and describes the basic principles, main features, and beneficial effects of the present invention. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, or improvements 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 superimposed adjustable differential pressure reducing valve, comprising a valve body, wherein the valve body is provided with a pressure inlet Pin, a pressure outlet Pout, a first load port A, and a second load port B; the valve body is provided with a spool valve core as a pressure-sensitive element, a pressure compensation spring, and a shuttle valve assembly; the two oil inlets of the shuttle valve assembly are respectively connected to the first load port A and the second load port B, characterized in that, It also includes a pressure regulating component, which includes a pressure regulating valve core, a spool valve sleeve, and a locking nut. The spool valve sleeve is fixedly installed in the valve body. The pressure regulating valve core is threadedly connected to the spool valve sleeve. The two ends of the pressure compensation spring abut against the pressure regulating valve core and the spool valve core, respectively. Rotating the pressure regulating valve core can adjust its relative displacement with the spool valve sleeve to change the preload of the pressure compensation spring. The locking nut is sleeved on the outer circumference of the pressure regulating valve core and is used to lock the relative position of the pressure regulating valve core and the spool valve sleeve after adjustment. The spool valve core is slidably disposed within the spool valve sleeve. The spool valve core cooperates with the throttling valve core fixed in the valve body to form a throttling assembly. The throttling valve core has at least two throttling holes circumferentially opened on it. The axial movement of the spool valve core can change the flow area of ​​the throttling holes to achieve the regulation of outlet pressure and flow rate. The oil outlet of the shuttle valve assembly is connected to the spring cavity where the pressure compensation spring is located through the damping hole, and the spring cavity is connected to the pressure outlet P. The shuttle valve assembly is also provided with a control flow channel connected to the external pressure regulating port Y, which is used to connect to an external control pressure higher than the pressure of the first load port A and the second load port B, so as to achieve constant differential regulation.

2. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The differential pressure adjustment range of the pressure compensation spring is 0.5-1.5 MPa.

3. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The number of throttling orifices is 4, and the 4 throttling orifices are evenly distributed along the circumference of the throttling valve core. The diameter of the throttling orifice is 3.2 mm, and the initial coverage of the spool valve core relative to the throttling orifice is 2.34 mm.

4. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The damping orifice has a diameter of 0.4 mm and a length of 0.38 mm.

5. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The shuttle valve assembly includes a shuttle valve body, a shuttle valve sleeve, and a steel ball. The shuttle valve sleeve is fixedly installed in the shuttle valve body, and the steel ball is movably disposed in the inner cavity of the shuttle valve sleeve, used to select the highest pressure among the first load port A, the second load port B, and the external pressure regulating port Y to be introduced into the damping orifice.

6. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, O-rings are provided between the spool valve sleeve and the valve body, between the pressure regulating valve core and the spool valve sleeve, between the spool valve core and the spool valve sleeve, and between the shuttle valve body and the valve body. A sealing ring is also provided between the mating surfaces of the spool valve core and the spool valve sleeve.

7. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The main flow channel of the valve body is a high-flow-rate, low-pressure-loss flow channel optimized by CFD simulation, and the maximum flow rate of the pressure reducing valve is 61.74 L / min.

8. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The pressure stabilizing valve core has a spring seat one at one end facing the pressure compensation spring, and the slide valve core has a spring seat two at one end facing the pressure compensation spring. The two ends of the pressure compensation spring are respectively limited and installed in the spring seat one and the spring seat two by spring washers.

9. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The internal thread of the locking nut mates with the external thread of the pressure regulating valve core. In the locked state, the end face of the locking nut is in close contact with the end face of the spool valve sleeve. The end of the pressure regulating valve core is also provided with a wire retaining ring to prevent the locking nut from coming out.

10. The superimposed adjustable differential pressure reducing valve according to claim 1, characterized in that, The throttling valve core is fixedly installed inside the slide valve sleeve by a retaining ring, and the end of the shuttle valve body is provided with a plug for blocking the process flow channel.

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