Overflow pilot valve and hydraulic control system and control method

Abstract

This invention discloses an overflow pilot valve, a hydraulic control system, and a control method. The overflow pilot valve includes: a first inlet channel, a second inlet channel, an overflow valve, an outlet channel, a first control device, and a second control device. The overflow valve includes an overflow port, a first inlet port, and a second inlet port. The overflow valve is connected to the first inlet channel through the first inlet port and to the second inlet channel through the second inlet port. When the pressure difference between the first inlet port and the second inlet port is greater than a preset value, the overflow port and the first inlet port are connected. The outlet channel includes a third inlet port, which is connected to the first inlet port. The first control device controls the connection between the first inlet channel and the first and third inlet ports, and the second control device controls the connection between the second inlet channel and the second inlet port. The overflow pilot valve of this invention can control the flow rate of the output liquid, thereby controlling the travel speed of the main valve core.

Description

Technical Field

[0001] This invention relates to the technical field of hydraulic valves, specifically to an overflow pilot valve and a hydraulic control system and control method. Background Technology

[0002] A hydraulic valve assembly is a control mechanism in a hydraulic control system used to manipulate other valves or components. In related technologies, the movement and position of the main valve spool are controlled by opening and closing the hydraulic valve assembly. However, the hydraulic valve assembly in these technologies cannot control the flow rate and pressure of the fluid input to the main valve assembly, resulting in an inability to control the travel speed of the main valve spool. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, this invention proposes an overflow pilot valve that can control the flow rate of the output liquid, thereby controlling the travel speed of the main valve core.

[0005] This invention also provides a hydraulic control system having the overflow pilot valve described in the above embodiments.

[0006] The overflow pilot valve of this invention includes: a first inlet channel and a second inlet channel; an overflow valve, the overflow valve including an overflow port, a first inlet port and a second inlet port, the overflow valve being connected to the first inlet channel through the first inlet port and to the second inlet channel through the second inlet port, wherein when the pressure difference between the first inlet port and the second inlet port is greater than a preset value, the overflow port and the first inlet port are connected to each other, so that the overflow valve is in an overflow state; an outlet channel, the outlet channel including a third inlet port, the third inlet port being connected to the first inlet port; and a first control device and a second control device, the first control device being used to control the first inlet channel to be connected to the first inlet port and the third inlet port, and the second control device being used to control the second inlet channel to be connected to the second inlet port.

[0007] In this embodiment of the invention, the overflow pilot valve utilizes a first control device and a second control device to control the opening and closing of the first and second inlet channels and the overflow valve, respectively, to regulate the pressure difference between the first and second inlet ports. This allows the overflow valve to overflow liquid in the overflow state, reducing the flow rate and pressure of the liquid output from the outlet channel. In the non-overflow state, the overflow valve does not overflow liquid, ensuring that all liquid entering the overflow valve through the first inlet port is discharged from the outlet channel. This results in a larger flow rate and pressure of the liquid discharged from the outlet channel, thereby achieving the goal of controlling the flow rate and pressure of the liquid output from the outlet channel. Thus, the problem of being unable to control the travel speed of the main valve core is solved.

[0008] Therefore, the overflow pilot valve of this embodiment of the invention can control the flow rate of the output liquid, thereby realizing the control of the travel speed of the main valve core.

[0009] In some embodiments, the overflow valve further includes: a first valve body and a first slider. The first valve body includes a first chamber, a first inlet, a second inlet, and an overflow port. The first slider is disposed in the first chamber and includes an annular protrusion that is adapted to the inner wall surface of the first chamber. The annular protrusion is located between the first inlet and the second inlet in the direction of the central axis of the first chamber. The first slider is movable along the central axis of the first chamber to allow the annular protrusion to move between a first position and a second position relative to each other in the direction of the central axis of the first chamber. When the annular protrusion is located in the second position, the overflow valve is in the overflow state.

[0010] In some embodiments, the inner wall surface of the first chamber includes a first segment, a second segment, and a first annular surface. The first segment and the second segment are opposite to each other in the direction of the central axis of the first chamber. The radial dimension of the first segment is smaller than that of the second segment. The inner end of the first annular surface is connected to the first segment, and the outer end of the first annular surface is connected to the second segment. The surface of the annular protrusion can abut against the first annular surface. The overflow valve also includes a first elastic element. One end of the first elastic element abuts against the first slider, and the other end of the first elastic element abuts against the second segment.

[0011] In some embodiments, the first control device includes a second valve body, a second slider, and a second elastic element. The second valve body includes a second chamber. The inner wall surface of the second chamber includes a third segment, a fourth segment, and a second annular surface that are opposite each other along the central axis of the second chamber. The radial dimension of the third segment is smaller than that of the fourth segment. The inner end of the second annular surface is connected to the third segment, and the outer end of the second annular surface is connected to the fourth segment. A fourth liquid inlet is provided on the fourth segment, and the fourth liquid inlet is connected to the first liquid inlet channel. A first liquid outlet and a second liquid outlet are provided on the third segment. The first liquid outlet is connected to the first liquid inlet, and the second liquid outlet is connected to the third liquid inlet. The second slider is disposed in the second chamber and is movable along the central axis of the second chamber. One end of the second slider can abut against the second annular surface. One end of the second elastic element abuts against the inner wall surface of the second chamber, and the other end of the second elastic element abuts against the other end of the second slider.

[0012] In some embodiments, the second valve body further includes: a third slider and a first pusher block, the third slider being movable along the central axis of the second valve body, the third slider defining a first balance chamber between itself and the inner wall surface of the second valve body, the inner wall surface of the first balance chamber being provided with a fifth liquid inlet, the fourth segment including a third liquid outlet communicating with the fifth liquid inlet, one end of the first pusher block contacting the second slider, and the other end of the first pusher block contacting the third slider.

[0013] In some embodiments, the first control device further includes: a first push rod, which passes through the second valve body and contacts the third slider.

[0014] In some embodiments, the second control device includes a third valve body, a fourth slider, and a third elastic element. The third valve body includes a third chamber. The inner wall of the third chamber includes a fifth segment, a sixth segment, and a third annular surface that are opposite each other along the central axis of the third chamber. The radial dimension of the fifth segment is smaller than that of the sixth segment. The inner end of the third annular surface is connected to the fifth segment, and the outer end of the third annular surface is connected to the sixth segment. A sixth liquid inlet is provided on the sixth segment, and the sixth liquid inlet is connected to the second liquid inlet channel. A fourth liquid outlet is provided on the fifth segment, and the fourth liquid outlet is connected to the second liquid inlet. The fourth slider is disposed in the third chamber and is movable along the central axis of the third chamber. One end of the fourth slider can abut against the third annular surface. One end of the third elastic element abuts against the inner wall of the third chamber, and the other end of the third elastic element abuts against the other end of the fourth slider.

[0015] In some embodiments, the third valve body further includes a fifth slider and a second pusher. The fifth slider is movable along the central axis of the third valve body. A second balance chamber is defined between the fifth slider and the inner wall surface of the third valve body. A seventh liquid inlet is provided on the inner wall surface of the second balance chamber. The sixth segment includes a fifth liquid outlet. The seventh liquid inlet communicates with the fifth liquid outlet. One end of the second pusher contacts the fourth slider, and the other end of the second pusher contacts the fifth slider. The second control device further includes a second push rod, which passes through the third valve body and contacts the fifth slider.

[0016] The hydraulic control system of this invention includes: an overflow pilot valve, wherein the overflow pilot valve is the overflow pilot valve described in any of the above embodiments, and the outlet channel further includes a sixth outlet; a main valve assembly, wherein the main valve assembly includes an eighth inlet, and the eighth inlet is connected to the sixth outlet.

[0017] The hydraulic control method of this invention includes: when the first inlet channel is connected to the first inlet port and the third inlet port, and the second inlet channel is disconnected from the second inlet port, the overflow valve is in the overflow state, so that the main valve assembly is in a first state; when the first inlet channel is connected to the first inlet port and the third inlet port, and the second inlet channel is connected to the second inlet port, so that the main valve assembly is in a second state; wherein, the valve core movement speed of the main valve assembly in the first state is less than the valve core movement speed of the main valve assembly in the second state. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overflow pilot valve and main valve assembly according to an embodiment of the present invention.

[0019] Figure label:

[0020] 100-type overflow pilot valve;

[0021] First liquid inlet channel 11; Second liquid inlet channel 12;

[0022] Overflow valve 2; First valve body 21; First inlet 211; Second inlet 212; First slider 22; Annular protrusion 221; First chamber 23; First section 231; Second section 232; First annular surface 233; First elastic element 24;

[0023] Liquid outlet channel 3; third liquid inlet 31; sixth liquid outlet 32;

[0024] First control device 4; second valve body 41; second slider 42; second elastic element 43; second chamber 44; third section 441; first outlet 4411; second outlet 4412; fourth section 442; fourth inlet 4421; third outlet 4422; second annular surface 443; first balance chamber 45; fifth inlet 451; third slider 46; first push block 47; first push rod 48;

[0025] Second control device 5; Third valve body 51; Fourth slider 52; Third elastic element 53; Third chamber 54; Fifth section 541; Fourth outlet 5411; Sixth section 542; Sixth inlet 5421; Fifth outlet 5422; Third annular surface 543; Second balance chamber 55; Seventh inlet 551; Fifth slider 56; Second push block 57; Second push rod 58;

[0026] Main valve assembly 200; eighth inlet 201; valve core 202. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] The overflow pilot valve 100 of the present invention is described below with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the overflow pilot valve 100 of this embodiment includes a first inlet channel 11, a second inlet channel 12, an overflow valve 2, an outlet channel 3, a first control device 4, and a second control device 5. The outlet channel 3 is the liquid output channel of the overflow pilot valve 100 of this embodiment, and is adapted to be connected to the main valve assembly to control the operation of the main valve assembly.

[0030] The overflow valve 2 includes an overflow port (not shown in the figure), a first inlet port 211, and a second inlet port 212. The overflow valve 2 can be connected to the first inlet channel 11 through the first inlet port 211, and the overflow valve 2 can be connected to the second inlet channel 12 through the second inlet port 212. In other words, the first inlet port 211 and the first inlet channel 11 can be connected or disconnected; the second inlet port 212 and the second inlet channel 12 can be connected or disconnected.

[0031] When the pressure difference between the first inlet 211 and the second inlet 212 is greater than a preset value, the overflow valve 2 is in an overflow state and the overflow port is connected to the first inlet 211. In other words, when the overflow valve 2 is in an overflow state, the overflow port and the first inlet 211 are connected. The outlet channel 3 includes a third inlet 31, which is connected to the first inlet 211.

[0032] The first control device 4 is used to control the first liquid inlet channel 11 to connect with the first liquid inlet 211 and the third liquid inlet 31, and the second control device 5 is used to control the second liquid inlet channel 12 to connect with the second liquid inlet 212.

[0033] The implementation process of the overflow pilot valve 100 of the present invention is described below with reference to the accompanying drawings.

[0034] When the required flow rate and pressure of the liquid output from the liquid outlet channel 3 are low, the first control device 4 controls the first liquid inlet channel 11 to connect with the first liquid inlet 211 and the third liquid inlet 31, allowing the liquid to flow from the first liquid inlet 211 into the overflow valve 2. The second control device 5 controls the second liquid inlet channel 12 to disconnect from the second liquid inlet 212, preventing the liquid from entering the second liquid inlet 212 through the second liquid inlet channel 12. This increases the pressure difference between the first liquid inlet 211 and the second liquid inlet 212 of the overflow valve 2 to a preset value, i.e., the overflow state, causing some of the liquid entering the overflow valve 2 to be discharged from the overflow port, thus reducing the flow rate and pressure of the liquid discharged from the third liquid inlet 31.

[0035] When the required flow rate and pressure of the liquid output from the liquid outlet channel 3 are high, the first control device 4 controls the first inlet channel 11 to connect with the first inlet port 211 and the third inlet port 31, allowing the liquid to flow from the first inlet port 211 into the overflow valve 2. The second control device 5 controls the second inlet channel 12 to connect with the second inlet port 212, allowing the liquid to enter the second inlet port 212 through the second inlet channel 12, making the pressure difference between the first inlet port 211 and the second inlet port 212 of the overflow valve 2 less than a preset value, i.e., a non-overflow state. As a result, all the liquid entering the overflow valve 2 through the first inlet port 211 is discharged from the third inlet port 31, thus making the flow rate and pressure of the liquid discharged from the liquid outlet channel 3 higher.

[0036] The first control device 4 controls the first liquid inlet channel 11 to disconnect from the first liquid inlet 211 and the third liquid inlet 31, so that the liquid outlet channel 3 stops outputting liquid.

[0037] In this embodiment of the invention, the overflow pilot valve 100 utilizes the first control device 4 and the second control device 5 to control the opening and closing of the first inlet channel 11 and the second inlet channel 12 with the overflow valve 2, adjusting the pressure difference between the first inlet port 211 and the second inlet port 212. This causes the overflow valve 2 to overflow liquid in the overflow state, reducing the flow rate and pressure of the liquid output from the outlet channel 3. In the non-overflow state, the overflow valve 2 does not overflow liquid, ensuring that all liquid entering the overflow valve 2 through the first inlet port 211 is discharged from the outlet channel 3. This results in a larger flow rate and pressure of the liquid discharged from the outlet channel 3, thereby achieving the goal of controlling the flow rate and pressure of the liquid output from the outlet channel 3. Thus, the problem of being unable to control the travel speed of the main valve core is solved.

[0038] The overflow pilot valve 100 of this embodiment of the invention can control the flow rate of the output liquid, thereby realizing the control of the travel speed of the main valve core.

[0039] It should be noted that the preset value needs to be determined based on the specific flow requirements of the main valve assembly, and is not limited here.

[0040] To make the solution easier to understand, the overflow pilot valve 100 of the present invention will be further described below with the central axis direction of the first chamber 23, the central axis direction of the second chamber 44, and the central axis direction of the third chamber 54 being consistent with the up and down direction.

[0041] In some embodiments, such as Figure 1 As shown, the overflow valve 2 further includes a first valve body 21 and a first slider 22. The first valve body 21 includes a first chamber 23, a first inlet 211, a second inlet 212, and an overflow port. The first slider 22 is disposed in the first chamber 23 and includes an annular protrusion 221. The annular protrusion 221 is adapted to the inner wall surface of the first chamber 23 and is located between the first inlet 211 and the second inlet 212 in the vertical direction of the first chamber 23. The first slider 22 is movable in the vertical direction of the first chamber 23 so that the annular protrusion 221 moves between a first position and a second position relative to each other in the direction of the central axis of the first chamber 23. One end of the first elastic member abuts against the first slider 22, and the other end of the first elastic member abuts against the inner wall surface of the first chamber 23. When the annular protrusion 221 is in the second position, the overflow valve 2 is in an overflow state.

[0042] When the required flow rate and pressure of the liquid output from the liquid outlet channel 3 are low, liquid flows into the overflow valve 2 from the first inlet 211. The first slider 22 moves downward under pressure, causing the liquid entering the first chamber 23 from the first inlet 211 to flow out from the overflow port. This reduces the flow rate and pressure of the liquid output from the liquid outlet channel 3.

[0043] When the required flow rate and pressure of the liquid output from the liquid outlet channel 3 are large, the liquid flows into the overflow valve 2 from the first inlet 211. The liquid enters the second inlet 212 through the second inlet channel 12, which balances the pressure on the first slider 22. The first slider 22 does not move, so the liquid cannot flow out from the overflow port. As a result, all the liquid that enters the overflow valve 2 through the first inlet 211 is discharged from the third inlet 31, thus achieving a large flow rate and pressure of the liquid discharged from the liquid outlet channel.

[0044] Therefore, the pressure difference between the first inlet 211 and the second inlet 212 is used to control the movement of the first slider 22, thereby controlling the state of the overflow valve 2, which is convenient to operate.

[0045] Specifically, the inner wall surface of the first chamber 23 includes a first segment 231, a second segment 232, and a first annular surface 233. The first segment 231 and the second segment 232 are opposite each other along the central axis of the first chamber 23. The radial dimension of the first segment 231 is smaller than that of the second segment 232. The inner end of the first annular surface 233 is connected to the first segment 231, and the outer end of the first annular surface 233 is connected to the second segment 232. The surface of the annular protrusion 221 can abut against the first annular surface 233. The upper end of the first elastic member abuts against the lower end of the first slider 22, and the lower end of the first elastic member abuts against the second segment 232. The first slider 22 is affected by the elastic force of the first elastic member. When the first slider 22 is not subjected to liquid pressure, the upper end of the first slider 22 abuts against the first annular surface 233.

[0046] In other words, when the pressure difference between the first inlet 211 and the second inlet 212 is large, the first slider 22 moves downward against the elastic force of the first elastic element, allowing the liquid entering from the first inlet 211 to flow out through the overflow port, thereby reducing the flow rate and pressure of the liquid output from the outlet channel 3. When the pressure difference between the first inlet 211 and the second inlet 212 is small, the first slider 22 cannot move downward against the elastic force of the first elastic element, and the first slider 22 remains against the first annular surface 233, preventing the liquid entering from the first inlet 211 from flowing out through the overflow port.

[0047] In some embodiments, such as Figure 1As shown, the first control device 4 includes a second valve body 41, a second slider 42, and a second elastic element 43. The second valve body 41 includes a second chamber 44. The inner wall surface of the second chamber 44 includes a third segment 441, a fourth segment 442, and a second annular surface 443 that are opposite each other in the vertical direction of the second chamber 44. The radial dimension of the third segment 441 is smaller than the radial dimension of the fourth segment 442, wherein the third segment 441 is located above the fourth segment 442.

[0048] The inner end of the second annular surface 443 is connected to the third segment 441, and the outer end of the second annular surface 443 is connected to the fourth segment 442. The fourth segment 442 is provided with a fourth liquid inlet 4421, which is connected to the first liquid inlet channel 11. The third segment 441 is provided with a first liquid outlet 4411 and a second liquid outlet 4412, which are connected to the first liquid inlet 211 and the second liquid outlet 4412 are connected to the third liquid inlet 31.

[0049] The second slider 42 is disposed in the second chamber 44. The second slider 42 is movable along the central axis of the second chamber 44. One end of the second slider 42 can abut against the second annular surface 443. One end of the second elastic member 43 abuts against the inner wall surface of the second chamber 44, and the other end of the second elastic member 43 abuts against the other end of the second slider 42.

[0050] When the second slider 42 is only subjected to the upward elastic force of the second elastic element 43, the second slider 42 abuts against the second annular surface 443. The liquid entering the second chamber 44 from the fourth inlet 4421 is blocked by the second slider 42 and cannot enter the first outlet 4411. When the second slider 42 is moved downward by other external forces, the second slider 42 separates from the second annular surface 443 and is no longer in contact. The liquid entering the second chamber 44 from the fourth inlet 4421 is not blocked by the second slider 42, and can thus enter the overflow valve 2 through the first outlet 4411 and the outlet channel 3 through the second outlet 4412. Therefore, the first control device 4 can realize the connection and disconnection of the first inlet channel 11 with the first inlet 211 and the third inlet 31, and the operation is simple.

[0051] Specifically, the second valve body 41 further includes a third slider 46 and a first push block 47. The third slider 46 is movable in the vertical direction, and a first balance chamber 45 is defined between the third slider 46 and the inner wall surface of the second valve body 41.

[0052] The inner wall of the first balance chamber 45 is provided with a fifth liquid inlet 451. The fourth section 442 includes a third liquid outlet 4422, which is connected to the fifth liquid inlet 451. One end of the first push block 47 is in contact with the second slider 42, and the other end of the first push block 47 is in contact with the third slider 46.

[0053] In other words, the connection between the third outlet 4422 and the fifth inlet 451 allows the oil to directly enter the first balance chamber 45. After the oil enters the first balance chamber 45, the third slider 46 is pressurized, balancing the third slider 46 with the second slider 42. This allows the first pusher 47 to push the second slider 42 downward with only a small downward force, making it easier for the operator to control the second slider 42 downward by controlling the third slider 46, thus reducing the difficulty of use.

[0054] In some embodiments, such as Figure 1 As shown, the first control device 4 further includes a first push rod 48, which passes through the second valve body 41 and contacts the third slider 46, thereby facilitating the movement of the third slider 46 using the first push rod 48, thereby further improving the practicality of the first control device 4.

[0055] In some embodiments, the second control device 5 includes a third valve body 51, a fourth slider 52, and a third elastic element 53. The third valve body 51 includes a third chamber 54. The inner wall surface of the third chamber 54 includes a fifth segment 541, a sixth segment 542, and a third annular surface 543 that are opposite each other in the vertical direction. The radial dimension of the fifth segment 541 is smaller than the radial dimension of the sixth segment 542. The inner end of the third annular surface 543 is connected to the fifth segment 541, wherein the fifth segment 541 is located above the sixth segment 542. The outer end of the third annular surface 543 is connected to the sixth segment 542. A sixth liquid inlet 5421 is provided on the sixth segment 542, which communicates with the second liquid inlet channel 12. A fourth liquid outlet 5411 is provided on the fifth segment 541, which communicates with the second liquid inlet 212.

[0056] The fourth slider 52 is located inside the third chamber 54. The fourth slider 52 is movable in the vertical direction, and one end of the fourth slider 52 can abut against the third annular surface 543. One end of the third elastic member 53 abuts against the inner wall surface of the third chamber 54, and the other end of the third elastic member 53 abuts against the other end of the fourth slider 52.

[0057] When the fourth slider 52 is only subjected to the upward elastic force of the third elastic element 53, the fourth slider 52 abuts against the third annular surface 543. The liquid entering the third chamber 54 from the sixth inlet 5421 is blocked by the fourth slider 52 and cannot enter the fourth outlet 5411. When the fourth slider 52 is moved downward by other external forces, the fourth slider 52 separates from the third annular surface 543 and no longer contacts it. The liquid entering the third chamber 54 from the sixth inlet 5421 is not blocked by the fourth slider 52 and can thus enter the overflow valve 2 through the fourth outlet 5411. Therefore, the second control device 5 can realize the connection and disconnection of the second inlet channel 12 and the second inlet 212, and the operation is simple.

[0058] In some embodiments, such as Figure 1 As shown, the third valve body 51 further includes a fifth slider 56 and a second pusher 57. The fifth slider 56 is movable in the vertical direction, and a second balance chamber 55 is defined between the fifth slider 56 and the inner wall surface of the third valve body 51.

[0059] The inner wall of the second balance chamber 55 is provided with a seventh liquid inlet 551, and the sixth section 542 includes a fifth liquid outlet 5422. The seventh liquid inlet 551 is connected to the fifth liquid outlet 5422. One end of the second push block 57 is in contact with the fourth slider 52, and the other end of the second push block 57 is in contact with the fifth slider 56.

[0060] In other words, the connection between the seventh inlet 551 and the fifth outlet 5422 allows the oil to directly enter the second balance chamber 55. After the oil enters the second balance chamber 55, the fifth slider 56 is subjected to downward pressure, thereby balancing the fifth slider 56 with the fourth slider 52. Consequently, the second pusher 57 only needs to be subjected to a small downward force to push the fourth slider 52 downward, making it easier for the operator to control the fourth slider 52 downward by controlling the fifth slider 56, thus reducing the difficulty of use.

[0061] In some embodiments, the second control device 5 further includes a second push rod 58, which passes through the third valve body 51 and contacts the fifth slider 56, thereby facilitating the movement of the fifth slider 56 using the second push rod 58, thereby further improving the practicality of the second control device 5.

[0062] The hydraulic control system of an embodiment of the present invention is described below with reference to the accompanying drawings.

[0063] The hydraulic control system of this invention includes an overflow pilot valve 100 and a main valve assembly 200. The overflow pilot valve 100 is the overflow pilot valve 100 in any of the above embodiments. The outlet channel 3 further includes a sixth outlet 32. The main valve assembly 200 includes an eighth inlet 201, which is connected to the sixth outlet 32.

[0064] Specifically, the main valve assembly 200 includes a cylinder and a valve core 202, with the valve core 202 movably disposed within the cylinder. When the liquid outlet channel 3 outputs a large flow of liquid to the main valve assembly 200, the valve core 202 moves at a faster speed; when the liquid outlet channel 3 outputs a small flow of liquid to the main valve assembly 200, the valve core 202 moves at a slower speed.

[0065] The overflow pilot valve 100 of the hydraulic control system in this embodiment of the invention can adjust the flow rate and pressure of the liquid output from the sixth outlet 32, thereby controlling the moving speed of the main valve core.

[0066] The hydraulic control method of the present invention is described below with reference to the accompanying drawings.

[0067] The hydraulic control method of this invention includes: when the first inlet channel is connected to the first inlet port and the third inlet port, and the second inlet channel is disconnected from the second inlet port, the overflow valve is in an overflow state, so that the main valve assembly is in a first state.

[0068] When the first liquid inlet channel is connected to the first liquid inlet and the third liquid inlet, and the second liquid inlet channel is connected to the second liquid inlet, the main valve assembly is in the second state.

[0069] In this case, the valve core movement speed of the main valve assembly in the first state is less than that of the valve core movement speed of the main valve assembly in the second state.

[0070] When the main valve assembly is in the first state, the first control device 4 controls the first liquid inlet channel 11 to connect with the first liquid inlet 211 and the third liquid inlet 31, so that liquid flows from the first liquid inlet 211 into the overflow valve 2. The second control device 5 controls the second liquid inlet channel 12 to disconnect from the second liquid inlet 212, so that liquid cannot enter the second liquid inlet 212 through the second liquid inlet channel 12, and increases the pressure difference between the first liquid inlet 211 and the second liquid inlet 212 of the overflow valve 2 to a preset value, i.e., the overflow state, so that part of the liquid entering the overflow valve 2 is discharged from the overflow port, thereby reducing the liquid flow rate and pressure discharged from the third liquid inlet 31.

[0071] When the main valve assembly is in the second state, the first control device 4 controls the first inlet channel 11 to connect with the first inlet port 211 and the third inlet port 31, so that liquid flows from the first inlet port 211 into the overflow valve 2. The second control device 5 controls the second inlet channel 12 to connect with the second inlet port 212, so that liquid enters the second inlet port 212 through the second inlet channel 12, making the pressure difference between the first inlet port 211 and the second inlet port 212 of the overflow valve 2 less than a preset value, i.e., a non-overflow state. As a result, all liquid entering the overflow valve 2 through the first inlet port 211 is discharged from the third inlet port 31, thus making the flow rate and pressure of the liquid discharged from the outlet channel 3 larger.

[0072] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0073] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0074] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0075] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0076] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0077] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A spill port pilot valve characterized by, include: First liquid inlet channel and second liquid inlet channel; An overflow valve is provided, comprising an overflow port, a first inlet port, and a second inlet port. The overflow valve is connected to a first inlet channel via the first inlet port and to a second inlet channel via the second inlet port. When the pressure difference between the first inlet port and the second inlet port is greater than a preset value, the overflow port and the first inlet port are connected to each other, so that the overflow valve is in an overflow state. A liquid outlet channel, the liquid outlet channel including a third liquid inlet, the third liquid inlet being connected to the first liquid inlet; and A first control device and a second control device, wherein the first control device is used to control the first liquid inlet channel to communicate with the first liquid inlet and the third liquid inlet, and the second control device is used to control the second liquid inlet channel to communicate with the second liquid inlet.

2. The overflow pilot valve according to claim 1, characterized in that, The overflow valve further includes: a first valve body and a first slider, the first valve body including a first chamber, a first inlet, a second inlet, and the overflow port. The first slider is disposed in the first chamber. The first slider includes an annular protrusion that is adapted to the inner wall surface of the first chamber. The annular protrusion is located between the first liquid inlet and the second liquid inlet in the direction of the central axis of the first chamber. The first slider is movable along the direction of the central axis of the first chamber so that the annular protrusion moves between a first position and a second position relative to each other in the direction of the central axis of the first chamber. When the annular protrusion is located in the second position, the overflow valve is in the overflow state.

3. The overflow pilot valve according to claim 2, characterized in that, The inner wall of the first chamber includes a first segment, a second segment, and a first annular surface. The first segment and the second segment are opposite each other along the central axis of the first chamber. The radial dimension of the first segment is smaller than that of the second segment. The inner end of the first annular surface is connected to the first segment, and the outer end of the first annular surface is connected to the second segment. The surface of the annular protrusion can abut against the first annular surface. The overflow valve further includes a first elastic element, one end of which abuts against the first slider, and the other end of which abuts against the second segment.

4. The overflow pilot valve according to any one of claims 1-3, characterized in that, The first control device includes a second valve body, a second slider, and a second elastic element. The second valve body includes a second chamber. The inner wall of the second chamber includes a third segment, a fourth segment, and a second annular surface opposite to each other along the central axis of the second chamber. The radial dimension of the third segment is smaller than that of the fourth segment. The inner end of the second annular surface is connected to the third segment, and the outer end of the second annular surface is connected to the fourth segment. A fourth liquid inlet is provided on the fourth segment, and the fourth liquid inlet communicates with the first liquid inlet channel. A first liquid outlet and a second liquid outlet are provided on the third segment. The first liquid outlet communicates with the first liquid inlet, and the second liquid outlet communicates with the third liquid inlet. The second slider is disposed in the second cavity. The second slider is movable along the central axis of the second cavity, and one end of the second slider can abut against the second annular surface. One end of the second elastic member abuts against the inner wall surface of the second cavity, and the other end of the second elastic member abuts against the other end of the second slider.

5. The overflow pilot valve according to claim 4, characterized in that, The second valve body further includes: a third slider and a first push block, wherein the third slider is movable along the central axis of the second valve body, and a first balance chamber is defined between the third slider and the inner wall surface of the second valve body. The inner wall of the first balance chamber is provided with a fifth liquid inlet, and the fourth section includes a third liquid outlet, which is connected to the fifth liquid inlet. One end of the first push block is in contact with the second slider, and the other end of the first push block is in contact with the third slider.

6. The overflow pilot valve according to claim 5, characterized in that, The first control device further includes: a first push rod, which passes through the second valve body and is in contact with the third slider.

7. The overflow pilot valve according to any one of claims 1-3, characterized in that, The second control device includes a third valve body, a fourth slider, and a third elastic element. The third valve body includes a third chamber. The inner wall of the third chamber includes a fifth segment, a sixth segment, and a third annular surface that are opposite each other along the central axis of the third chamber. The radial dimension of the fifth segment is smaller than that of the sixth segment. The inner end of the third annular surface is connected to the fifth segment, and the outer end of the third annular surface is connected to the sixth segment. A sixth liquid inlet is provided on the sixth segment, which communicates with the second liquid inlet channel. A fourth liquid outlet is provided on the fifth segment, which communicates with the second liquid inlet. The fourth slider is disposed in the third chamber. The fourth slider is movable along the central axis of the third chamber, and one end of the fourth slider can abut against the third annular surface. One end of the third elastic member abuts against the inner wall surface of the third chamber, and the other end of the third elastic member abuts against the other end of the fourth slider.

8. The overflow pilot valve according to claim 7, characterized in that, The third valve body further includes a fifth slider and a second pusher. The fifth slider is movable along the central axis of the third valve body, and a second balance chamber is defined between the fifth slider and the inner wall surface of the third valve body. The inner wall of the second balance chamber is provided with a seventh liquid inlet, and the sixth section includes a fifth liquid outlet. The seventh liquid inlet is connected to the fifth liquid outlet. One end of the second push block contacts the fourth slider, and the other end of the second push block contacts the fifth slider; The second control device further includes a second push rod, which passes through the third valve body and contacts the fifth slider.

9. A hydraulic control system, characterized in that, include: An overflow pilot valve, wherein the overflow pilot valve is the overflow pilot valve according to any one of claims 1-8, and the liquid outlet channel further includes a sixth liquid outlet; The main valve assembly includes an eighth liquid inlet, which is connected to the sixth liquid outlet.

10. A hydraulic control method, characterized in that, The hydraulic control system according to claim 9 includes: When the first liquid inlet channel is connected to the first liquid inlet and the third liquid inlet, and the second liquid inlet channel is disconnected from the second liquid inlet, the overflow valve is in the overflow state, so that the main valve assembly is in the first state; When the first liquid inlet channel is connected to the first liquid inlet and the third liquid inlet, and the second liquid inlet channel is connected to the second liquid inlet, the main valve assembly is in a second state. Wherein, the valve core movement rate of the main valve assembly in the first state is less than the valve core movement rate of the main valve assembly in the second state.

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