Balance valve with pilot ratio self-adaptively adjusted based on flow change and working method

Abstract

The application relates to the hydraulic technology field, and relates to a balance valve based on flow change self-adaptive adjustment of a pilot ratio and a working method. The balance valve comprises a valve body (1) and a balance valve assembly (2). A main hole (11) is formed in the valve body (1). A load port (13) and an oil inlet (12) in communication with the main hole (11) are also formed in the valve body (1). The balance valve assembly (2) is arranged in the main hole (11) and realizes the on / off of the load port (13) and the oil inlet (12). A pilot oil hole (14) is also formed in the valve body (1). A pilot oil working hole (142) in communication with the inner end of the main hole (11) is formed in the middle of the pilot oil hole (14). The inner end of the balance valve assembly (2) is provided with a pilot control surface (26). The balance valve further comprises a flow sensing structure and a differential adjustment module (3). The application has the advantages of ingenious design, simple structure, low cost and good operation effect.

Description

Technical Field

[0001] This invention relates to the field of hydraulic technology, and in particular to improvements on pilot control balance valves and their operating methods. Background Technology

[0002] Currently, most balancing valves have a fixed pilot ratio, commonly 3:1, 4.5:1, and 10:1. A larger pilot ratio results in high opening sensitivity, allowing the valve to open with relatively low control pressure. However, even slight fluctuations in control pressure can lead to frequent, repeated opening and closing of the valve, causing vibration and poor stability in the end-effector, thus affecting the safety of the main unit. Conversely, a smaller pilot ratio requires higher control pressure to open the valve, resulting in higher system energy consumption. In practical applications, the main unit needs to select an appropriate pilot ratio to balance system stability and energy consumption. A very small number of balancing valves with special requirements may have an adjustable pilot ratio, but these are fixed values. Changing them requires stopping the machine, disassembling and replacing parts, or adjusting the corresponding screw, which is cumbersome in actual operation. Figure 11 As shown, the pilot oil acts on the inner end of the valve core of the balance valve 2 through the pilot oil passage 142 in the pilot oil hole 14, forming a control state with a fixed pilot ratio.

[0003] To achieve a variable pilot ratio, the existing patent technology "CN 108223493A, titled: A balancing valve with a variable pilot ratio" aims to "use a low pilot ratio under conditions requiring high system stability and a high pilot ratio under steady-state conditions, thereby reducing system energy consumption." This patent provides a balancing valve with a variable pilot ratio. It uses a stepped pilot control valve block, changing the pilot ratio by altering the number of steps the pilot control oil acts on. This results in a step change during switching, which is detrimental to the stable operation of the actuator. Furthermore, it requires high precision and sealing between different steps, leading to high manufacturing costs. Additionally, the pilot ratio in this document is manually controlled according to different stages of equipment use, and cannot automatically match the actual operating conditions of the system.

[0004] Therefore, how to automatically match the system operating conditions and automatically adjust the pilot ratio according to the system operating conditions has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the above-mentioned technical problems, this invention provides a balancing valve and its operating method that can automatically adjust the pilot ratio based on the real-time flow rate of the valve components, thereby improving system operational stability and reducing energy consumption.

[0006] The technical solution of the present invention is as follows: it includes a valve body (1) and a balance valve assembly (2). A main hole (11) is provided on the valve body (1). A load port (13) and an oil inlet (12) communicating with the main hole (11) are also provided on the valve body (1). The balance valve assembly (2) is located in the main hole (11) to realize the opening / closing of the load port (13) and the oil inlet (12). A pilot oil hole (14) is also provided on the valve body (1). A pilot oil working channel (142) communicating with the inner end of the main hole (11) is provided in the middle of the pilot oil hole (14). The inner end of the balance valve assembly (2) has a pilot control surface (26).

[0007] It also includes a flow sensing structure and a differential control module (3);

[0008] The differential adjustment module (3) includes a differential adjustment module mounting hole (30) that penetrates the pilot oil hole (14) vertically. A differential spring A (32), a differential valve core (31) and a differential spring B (33) are provided in the differential adjustment module mounting hole (30). A ring groove (311) is provided in the middle of the differential valve core (31). Differential cavity A and differential cavity B are formed on both sides of the differential valve core (31).

[0009] The flow sensing structure includes a flow sensing module (132) disposed in the load port (13). The flow sensing module (132) has a small hole (1321). An oil passage A (130) communicating with the differential cavity A is provided at the upper part of the flow sensing module (132), and an oil passage B (131) communicating with the differential cavity B is provided at the lower part of the flow sensing module (132).

[0010] Furthermore, the width of the annular groove (311) opened on the differential valve core (31) is adapted to the diameter of the pilot oil passage (141) in the pilot oil hole (14).

[0011] Furthermore, in the initial state, the annular groove (311) and the pilot oil passage (141) form the minimum flow area.

[0012] Furthermore, when the pressure difference between the differential chamber A and the differential chamber B increases, the differential valve core (31) moves, thereby increasing the flow area between the annular groove (311) and the pilot oil passage (141).

[0013] Furthermore, the differential adjustment module (3) also includes an adjustment mechanism (34) for realizing the left and right extreme positions of the differential valve core (31). The adjustment mechanism (34) includes a stepped surface (342) provided in the differential cavity B and an adjustment rod (341) provided in the differential cavity A.

[0014] Furthermore, the flow sensing module (132) is connected to the load port (13) via an external thread structure.

[0015] Furthermore, a damper (143) is provided at the outlet of the pilot oil passage.

[0016] The present invention relates to a working method of a balance valve based on adaptive adjustment of pilot ratio according to flow rate change. The load port (13) is connected to the working cylinder, the oil inlet (12) is connected to the hydraulic control valve, and the pilot oil hole (14) is connected to the pilot control valve or the oil return chamber of the working cylinder.

[0017] Follow these steps:

[0018] 1) When the pressure of the pilot control valve or the oil return chamber of the working cylinder reaches the set value, the pilot oil flows through the pilot oil working channel (142) and acts on the pilot control surface (26) to drive the balance valve core (21) to move, and connect the load port (13) and the oil inlet (12).

[0019] 2) The upper and lower pressure difference of the flow sensing module (132) in the load port (13) will be generated, which will be reflected to the differential chamber A and differential chamber B through oil passage A (130) and oil passage B (131) respectively. In the initial stage of operation, the flow rate is small and the pressure difference is also small. The differential valve core basically does not move and the pilot ratio is low. The initial stage of operation has good stability.

[0020] 3) As the flow rate increases, the resulting pressure difference drives the differential valve core (31) to move. The pilot oil flows through the channel (141) and widens. The damper (143) enhances its throttling effect. The pressure acting on the pilot control surface (26) gradually increases, and the pilot ratio gradually increases. The valve opening degree increases, the pressure loss decreases, and energy saving is achieved.

[0021] This invention combines the operating status of hydraulic oil flow at the load port with the flow sensing module installed in the load port and the differential adjustment module installed in the pilot oil flow channel to obtain flow changes and convert the flow changes into "pressure difference"; then, the "pressure difference" is used as the basis for adjusting the pilot oil working pressure. This invention makes full use of fluid characteristics and realizes dynamic adjustment of the pilot ratio during operation. In the initial stage of system operation, due to the small flow and small pressure difference, the differential valve core hardly moves, and the pilot ratio is low; the initial stage of operation is stable. As the flow increases, the pressure difference drives the differential valve core to move, the pilot oil flow channel widens, the damper (143) throttling effect is enhanced, the pressure acting on the pilot control surface gradually increases, the pilot ratio gradually increases, the valve opening degree increases, the pressure loss decreases, and energy saving is achieved. Ultimately, the stability of the system during operation is improved, and the operating energy consumption is reduced. This invention has an ingenious concept, simple structure, low cost, and good operating effect. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the present invention.

[0023] Figure 2 yes Figure 1 Top view,

[0024] Figure 3 yes Figure 2 Sectional view AA

[0025] Figure 4 yes Figure 2 BB section view,

[0026] Figure 5 This is a schematic diagram of the differential valve core in this invention.

[0027] Figure 6 yes Figure 5 The right view,

[0028] Figure 7 This is a schematic diagram of the flow sensing module in this invention.

[0029] Figure 8 yes Figure 7 The left view;

[0030] Figure 9 yes Figure 3 Enlarged view of a section at point M.

[0031] Figure 10 This is a schematic diagram of the working principle of the present invention;

[0032] Figure 11 This is a structural schematic diagram of the background technology of this invention.

[0033] In the diagram, 1 is the valve body, 11 is the main port, 12 is the oil inlet, 13 is the load port, 130 is oil passage A, 131 is oil passage B, 132 is the flow sensing module, and 1321 is the small orifice.

[0034] 14 is the pilot oil hole, 141 is the pilot oil passage, 142 is the pilot oil working passage, and 143 is the damper.

[0035] 2 is the balance valve assembly, 21 is the balance valve core, 221 is the check valve spring seat, 222 is the check valve seat, 23 is the valve sleeve, 24 is the balance valve main spring, 241 is the main spring seat, 251 is the adjusting screw, 252 is the adjusting nut, and 26 is the pilot control surface.

[0036] 3 is the differential adjustment module, 30 is the differential adjustment module mounting hole, 31 is the differential valve core, 311 is the annular groove, 312 is the sealing groove, 313 is the end groove, 32 is the differential spring A, 33 is the differential spring B, 34 is the adjustment mechanism, 341 is the adjustment rod, and 342 is the stepped surface.

[0037] Figure 3 , 9 The dashed arrows in 10 indicate the direction of the working hydraulic oil flow, while the dotted arrows indicate the direction of the pilot oil flow. Detailed Implementation

[0038] The technical solution of the present invention is as follows Figure 1-10 As shown: It includes a valve body 1 and a balance valve assembly 2. A main hole 11 is provided on the valve body 1. A load port 13 and an oil inlet 12 communicating with the main hole 11 are also provided on the valve body 1. The balance valve assembly 2 is located in the main hole 11 and realizes the opening or closing of the load port 13 and the oil inlet 12. A pilot oil hole 14 is also provided on the valve body 1. A pilot oil working channel 142 communicating with the inner end of the main hole 11 is provided in the middle of the pilot oil hole 14. The inner end of the balance valve assembly 2 has a pilot control surface 26.

[0039] The balance valve assembly 2 includes a balance valve core 21, a one-way valve spring seat 221, a one-way valve seat 222, a valve sleeve 23, a balance valve main spring 24, a main spring seat 241, an adjusting screw 251, and an adjusting nut 252, etc. Since the balance valve assembly 2 is a conventional technology in this field, its specific structure will not be described in detail in this case.

[0040] The core innovation of this invention is that the valve body 1 also includes a flow sensing structure and a differential adjustment module 3;

[0041] The differential adjustment module 3 includes a differential adjustment module mounting hole 30 that penetrates the pilot oil hole 14 vertically. A differential spring A32, a differential valve core 31, and a differential spring B33 are provided in the differential adjustment module mounting hole 30. A ring groove 311 is provided in the middle of the differential valve core 31, and differential chamber A and differential chamber B are formed on both sides of the differential valve core 31.

[0042] The flow sensing structure includes a flow sensing module 132 disposed in the load port 13. The flow sensing module 132 has a small hole 1321. An oil passage A130 communicating with the differential cavity A is provided at the upper part of the flow sensing module 132, and an oil passage B131 communicating with the differential cavity B is provided at the lower part of the flow sensing module 132.

[0043] Furthermore, the width of the annular groove 311 opened on the differential valve core 31 is adapted to the diameter of the pilot oil passage 141 in the pilot oil hole 14.

[0044] In the initial state, the annular groove 311 and the pilot oil passage 141 form the minimum flow area δ1 (e.g. Figure 9(As shown). That is, when designing the width and initial position of the annular groove 311, a certain gap is left to ensure the flow of pilot oil. Of course, regarding the depth of the differential adjustment module mounting hole 30, those skilled in the art can understand, based on the technical task set by this invention, that a certain space needs to be designed to allow the differential valve core 31 to move left and right, so as to change the flow area. For example, as the flow rate at the load port 13 increases, when a large pressure difference is formed above and below the flow sensing module 132, the upper pressure is reflected to the differential chamber A (as shown). Figure 3 The lower pressure is reflected to the differential chamber B via oil passage B131. Figure 4 This will drive the differential valve core 31 to move to the right side of the diagram, gradually increasing the flow area of ​​the pilot oil until the maximum flow area δ2 is reached (e.g., Figure 10 (As shown); this invention enables the pilot ratio to be adaptively adjusted as the operating conditions change. That is, when the pressure difference between differential chamber A and differential chamber B increases, the differential valve core 31 moves, thereby increasing the flow area between the annular groove 311 and the pilot oil passage 141.

[0045] Furthermore, the differential adjustment module 3 also includes an adjustment mechanism 34 for realizing the left and right extreme positions of the differential valve core 31. The adjustment mechanism 34 includes a stepped surface 342 disposed in the differential cavity B and an adjustment rod 341 disposed in the differential cavity A. This enables the adjustment of the initial position of the differential valve core 31 and the limiting of its maximum extreme position. The purpose of adjusting the left and right extreme positions of the differential valve core 31 is to adjust and control the maximum and minimum pilot ratios in specific situations according to actual operating needs.

[0046] Furthermore, the flow sensing module 132 is connected to the load port 13 via an external thread structure. The distance between oil passage A130 and oil passage B131 can be designed to be greater than the thickness of the flow sensing module 132. This facilitates the installation of the flow sensing module 132 and also allows for adjustment of the installation height of the flow sensing module 132, enabling the adjustment of various pilot ratios and flow rates.

[0047] Furthermore, a damper 143 is provided at the outlet of the pilot oil passage. The pilot oil passage 141 and the damper 143 form a liquid bridge. That is, the pressure acting on the pilot control surface 26 depends on the relationship between the flow areas of the pilot oil passage 141 and the damper 143. When the pressure of the pilot oil hole 14 is constant, the larger the flow area of ​​the pilot oil passage 141 relative to the flow area of ​​the damper 143, the greater the pressure acting on the pilot control surface 26 and the greater the pilot ratio; the smaller the flow area of ​​the pilot oil passage 141 relative to the flow area of ​​the damper 143, the smaller the pressure acting on the pilot control surface 26 and the smaller the pilot ratio.

[0048] The present invention relates to a method for operating a balance valve based on adaptive adjustment of pilot ratio according to flow rate changes. The load port 13 is connected to the working cylinder, the oil inlet 12 is connected to the hydraulic control valve, and the pilot oil hole 14 is connected to the pilot control valve or the oil return chamber of the working cylinder.

[0049] Follow these steps:

[0050] 1) When the pressure in the return oil chamber of the pilot control valve or working cylinder reaches the set value, the pilot oil flows through the pilot oil working channel 142 to trigger the pilot control surface 26 to drive the balance valve core 21 to move, connecting the load port 13 and the oil inlet 12.

[0051] 2) A pressure difference will be generated between the upper and lower parts of the flow sensing module 132 in the load port 13, which will be reflected to the differential chamber A and differential chamber B through oil passage A130 and oil passage B131 respectively. In the initial stage of operation, the flow rate is small and the pressure difference is also small. The differential valve core hardly moves and the pilot ratio is low. The operation stability is good in the initial stage.

[0052] 3) As the flow rate increases, the resulting pressure difference drives the differential valve core 31 to move. The pilot oil flows through a wider channel, and the pressure acting on the pilot control surface 26 of the balance valve core 21 gradually increases, thus gradually increasing the pilot ratio and achieving energy saving.

[0053] The change in the cross-sectional area of ​​the pilot oil passage in this invention causes a change in the pressure of the pilot oil acting on the pilot control surface 26 of the balance valve core 21. Specifically, the smaller the cross-sectional area δ, the lower the pilot oil pressure acting on the pilot control surface 26, and the smaller the pilot ratio; conversely, the larger the cross-sectional area δ, the higher the pilot oil pressure acting on the pilot control surface 26, and the larger the pilot ratio. This allows for adaptive adjustment of the pilot ratio based on the flow rate. Specifically, at low flow rates, the pilot ratio is small, preventing slight fluctuations in the pilot oil from causing erroneous opening or vibration of the balance valve; at high flow rates, the pilot ratio is large, reducing the required pilot oil pressure and lowering energy consumption. Furthermore, the smooth change in the pilot ratio during operation is beneficial for the stable operation of the actuator.

[0054] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A balance valve that adaptively adjusts the pilot ratio based on flow rate changes, comprising a valve body (1) and a balance valve assembly (2), wherein a main hole (11) is provided on the valve body (1), and a load port (13) and an oil inlet (12) communicating with the main hole (11) are also provided on the valve body (1), the balance valve assembly (2) is disposed in the main hole (11) to realize the opening and closing of the load port (13) and the oil inlet (12), and a pilot oil hole (14) is also provided on the valve body (1), wherein a pilot oil working channel (142) communicating with the inner end of the main hole (11) is provided in the middle of the pilot oil hole (14); the inner end of the balance valve assembly (2) has a pilot control surface (26). Its features are, It also includes a flow sensing structure and a differential control module (3); The differential adjustment module (3) includes a differential adjustment module mounting hole (30) that penetrates the pilot oil hole (14) vertically. A differential spring A (32), a differential valve core (31) and a differential spring B (33) are provided in the differential adjustment module mounting hole (30). A ring groove (311) is provided in the middle of the differential valve core (31). Differential cavity A and differential cavity B are formed on both sides of the differential valve core (31). The flow sensing structure includes a flow sensing module (132) disposed in the load port (13). The flow sensing module (132) has a small hole (1321). An oil passage A (130) communicating with the differential cavity A is provided at the upper part of the flow sensing module (132), and an oil passage B (131) communicating with the differential cavity B is provided at the lower part of the flow sensing module (132).

2. The balancing valve based on adaptive adjustment of pilot ratio according to flow rate change as described in claim 1, characterized in that, The width of the annular groove (311) on the differential valve core (31) is adapted to the diameter of the pilot oil passage (141) in the pilot oil hole (14).

3. The balancing valve based on adaptive adjustment of pilot ratio according to flow rate change as described in claim 2, characterized in that, In its initial state, the annular groove (311) forms the minimum flow area with the pilot oil passage (141).

4. The balancing valve based on adaptive adjustment of pilot ratio according to flow rate change as described in claim 3, characterized in that, When the pressure difference between the differential chamber A and the differential chamber B increases, the differential valve core (31) moves, thereby increasing the flow area between the annular groove (311) and the pilot oil passage (141).

5. The balancing valve based on adaptive adjustment of pilot ratio according to flow rate change as described in claim 1, characterized in that, The differential adjustment module (3) further includes an adjustment mechanism (34) for realizing the left and right extreme positions of the differential valve core (31). The adjustment mechanism (34) includes a stepped surface (342) provided in the differential cavity B and an adjustment rod (341) provided in the differential cavity A.

6. The balancing valve based on adaptive adjustment of pilot ratio according to flow rate change as described in claim 1, characterized in that, The flow sensing module (132) is connected to the load port (13) via an external thread structure.

7. The balancing valve based on adaptive adjustment of pilot ratio according to flow rate change as described in claim 2, characterized in that, A damper (143) is also provided at the outlet of the pilot oil passage (141).

8. A method for operating a balance valve based on adaptive adjustment of pilot ratio according to claim 1, wherein the load port (13) is connected to the working cylinder, the oil inlet (12) is connected to the hydraulic control valve, and the pilot oil hole (14) is connected to the pilot control valve or the oil return chamber of the working cylinder; Its features are, Follow these steps: 1) When the pressure of the pilot control valve or the oil return chamber of the working cylinder reaches the set value, the pilot oil flows through the pilot oil working channel (142) and acts on the pilot control surface (26) to drive the balance valve core (21) to move, and connect the load port (13) and the oil inlet (12). 2) The pressure difference between the upper and lower parts of the flow sensing module (132) in the load port (13) will be reflected to the differential chamber A and differential chamber B through oil passage A (130) and oil passage B (131) respectively. In the initial stage of operation, the flow rate is small and the pressure difference is also small. The differential valve core basically does not move and the pilot ratio is low. The operation stability is good in the initial stage. 3) As the flow rate increases, the resulting pressure difference drives the differential valve core (31) to move, the pilot oil passage (141) widens, the damper (143) throttling effect is enhanced, the pressure acting on the pilot control surface (26) gradually increases, the pilot ratio gradually increases; the valve opening degree increases, the pressure loss decreases, and energy saving is achieved.

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