Flow dynamic shutoff valve, flow recycling system and control method

Abstract

This invention discloses a dynamic flow shut-off valve, a flow regeneration and utilization system, and a control method. The dynamic flow shut-off valve includes: a hydraulically controlled pilot valve, a spool valve, a first control port Pi1 and a second control port Pi2, an inlet port P1, and an outlet port P2. The control oil output through the first and second control ports Pi1 and Pi2 controls the hydraulic pressure difference between the spool valve in the left and right working positions, thus controlling the valve orifice area. Based on the valve orifice area, the flow rate of the spool valve oil from the inlet port P1 to the outlet port P2 is controlled. Advantages: During boom descent and other actuators performing combined actions, the dynamic flow shut-off valve allows more flow to be directed to other actuators, accelerating their operation and improving work efficiency. Furthermore, the first valve core of the boom independently controls the return oil and back pressure of the boom's large chamber, no longer controlling the inlet oil of the boom's small chamber, avoiding the defects of single-valve core inlet and return valve orifice linkage control, and increasing control flexibility.

Description

Technical Field

[0001] This invention relates to a dynamic flow shut-off valve, a flow regeneration and utilization system, and a control method, belonging to the field of hydraulic technology. Background Technology

[0002] Large and medium-sized excavators have heavy booms with significant potential energy after lifting. Therefore, boom descent can be achieved entirely through this potential energy and the regenerative flow from the large boom chamber, eliminating the need for a hydraulic pump. However, due to the boom's weight, the back pressure in the large boom chamber is high during descent to prevent stalling. Excess high-pressure hydraulic fluid returns directly to the tank after being throttled by the boom valve, resulting in significant throttling losses and energy waste. This leads to increased system fluid temperature, reduced component lifespan, and increased power consumption for engine fan cooling. Furthermore, in actual excavator operation, the boom frequently interacts with other actuators such as the stick. Under current technology, the hydraulic fluid in the large boom chamber cannot be directly regenerated for use in these actuators during boom descent. The stick's flow needs to be pumped from the tank, increasing engine power consumption. Moreover, during multi-actuator interactions, insufficient flow can cause cylinder cavitation, reduced speed, and decreased operating efficiency in other actuators like the stick.

[0003] Therefore, when the boom is lowered, dynamically cutting off the flow supply from the pump to the boom according to the actual working conditions, and directly regenerating the flow in the boom cavity to other actuators such as the stick, reducing the return oil flow in the boom cavity and the output flow of the pump, reducing throttling losses, improving the excavator's handling performance, and increasing operating efficiency have always been the key points for energy conservation, emission reduction and efficiency improvement in excavators. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a flow dynamic shut-off valve, a flow regeneration and utilization system and a control method.

[0005] To solve the above-mentioned technical problems, the present invention provides a flow dynamic shut-off valve, comprising: a hydraulic pilot valve, a slide valve, a first control port Pi1 and a second control port Pi2, an inlet port P1 and an outlet port P2;

[0006] The first control port Pi1 is connected to the left working position control port of the slide valve and the upper working position control port of the hydraulic pilot valve; the second control port Pi2 is connected to the oil inlet of the hydraulic pilot valve.

[0007] The oil inlet P1 is connected to the oil inlet of the slide valve; the oil outlet P2 is connected to the oil outlet of the slide valve.

[0008] The first control port Pi1 is connected to the boom lowering pilot oil pipe, and the second control port Pi2 is connected to the pilot oil pipes of other actuators.

[0009] The control oil output through the first control port Pi1 and the second control port Pi2 controls the hydraulic pressure difference between the left and right working positions of the slide valve, controls the valve port area, and controls the flow rate of the slide valve oil from the inlet P1 to the outlet P2 according to the valve port area.

[0010] Furthermore, the switching method of the slide valve adopts hydraulic differential pressure proportional switching.

[0011] A flow regeneration and utilization system, comprising:

[0012] First pump, second pump, pilot pump, engine, oil tank, boom cylinder, boom first valve core, boom second valve core, boom third valve core, boom fourth valve core, first to ninth pilot valves, flow dynamic shut-off valve, other actuator first valve core, other actuator second valve core, regeneration check valve, supply pipeline connecting actuator cylinders and various hydraulic valves;

[0013] The first pump, the second pump, and the pilot pump are connected to the engine and draw hydraulic oil from the oil tank;

[0014] The oil output from the first pump flows through the first pump supply pipeline to the flow dynamic shut-off valve, the first valve core of the boom, the fourth valve core of the boom, and the second valve core of other actuators respectively.

[0015] The oil output from the second pump flows through the second supply pipeline to the second boom valve core, the third boom valve core, and the first valve core of other actuators respectively;

[0016] The oil output by the pilot pump flows to the first to ninth pilot valves respectively through the third supply pipeline;

[0017] The first pilot valve is connected to the right working position control port of the second valve core of the boom through the first pilot oil pipe, and controls the confluence of the first pump and the second pump when the boom is lifted;

[0018] The second pilot valve is connected to the left working position control port of the first valve core of the boom via the second pilot oil pipe to control the boom lifting.

[0019] The third pilot valve is connected to the right working position control port of the first valve core of the boom via the third pilot oil pipe, controlling the boom descent return oil and back pressure;

[0020] The fourth pilot valve is connected to the left working position control port of the third valve core of the boom through the fourth pilot oil pipe, and controls the regenerative flow from the large chamber to other actuators when the boom descends;

[0021] The fifth pilot valve is connected to the right working position control port of the fourth valve core of the boom through the fifth pilot oil pipe, and controls the return oil and back pressure of the boom descent;

[0022] The sixth pilot valve is connected to the left working position control port of the first valve core of other actuators through the sixth pilot oil pipe;

[0023] The seventh pilot valve is connected to the right working position control port of the first valve core of other actuators through the seventh pilot oil pipe;

[0024] The eighth pilot valve is connected to the left working position control port of the second valve core of other actuators through the eighth pilot oil pipe;

[0025] The ninth pilot valve is connected to the right working position control port of the second valve core of other actuators through the ninth pilot oil pipe;

[0026] The flow dynamic shut-off valve is connected in series with the boom first valve core via an oil pipe and controls the first pump to supply oil to the boom first valve core.

[0027] Furthermore, the other actuators include a stick.

[0028] Furthermore, it also includes: other actuator cylinders, which are connected to other actuators.

[0029] Furthermore, it also includes: pressure sensors, operating handles, and controllers;

[0030] Pressure sensors are used to detect and identify operating conditions;

[0031] The control handle is used to issue operating command signals for lowering the boom and swinging the stick outward;

[0032] The controller receives the output signals from the pressure sensor and the handle, processes and analyzes them, and sends command control signals to the first to ninth pilot valves. Each pilot valve outputs the corresponding pilot pressure according to the input command signal and connects the corresponding working position of the valve core.

[0033] An excavator includes the aforementioned flow regeneration system.

[0034] A control method for a flow regeneration and utilization system includes:

[0035] During the combined action of boom descent and stick outward swing, oil enters the small chamber of the stick cylinder and returns oil to the large chamber. The flow dynamic shut-off valve dynamically cuts off the oil supply from the first pump to the first valve core of the boom according to the actual working conditions, further cutting off the oil supply to the small chamber of the boom. The large chamber of the boom cylinder returns oil through the first valve core and the fourth valve core of the boom, and is regenerated to the stick through the third valve core of the boom.

[0036] Furthermore, the process of the combined action of boom lowering and stick swing includes:

[0037] When the operating handle sends an operating command signal for lowering the boom and swinging the stick outward, it is transmitted to the controller. The controller analyzes and processes the operating command and sends command control signals to the first to ninth pilot valves. Each pilot valve outputs the corresponding pilot pressure according to the input command signal and connects the corresponding working position of the valve core.

[0038] After receiving the command signal, the pilot pressure output by the seventh and eighth pilot valves respectively causes the first valve core of the stick to enter the right working position and the second valve core of the stick to enter the left working position, thereby connecting the supply lines of the second and first pumps to the small chamber of the stick cylinder. At the same time, the oil in the large chamber of the stick cylinder returns to the oil tank through the right working position of the first valve core of the stick and the left working position of the second valve core of the stick.

[0039] The third and fifth pilot valves, upon receiving the received operation command, output pilot pressures that cause the first and fourth boom valve spools to enter the right working position, respectively. This connects the oil pipe of the first boom valve spool to the outlet P2 of the flow dynamic shut-off valve. Simultaneously, the oil in the large boom chamber returns to the oil tank through the right working position of the first and fourth boom valve spools. Furthermore, when the pressure in the small boom chamber is lower than the opening pressure of the replenishing check valve, the replenishing check valve replenishes oil to the small boom chamber.

[0040] After receiving the operation command, the fourth pilot valve outputs pilot pressure, which causes the third valve core of the boom to enter the left working position, connecting the boom large chamber with the supply line before the regeneration check valve. When the back pressure of the return oil in the boom large chamber is greater than the pressure of the supply line of the second pump, the regeneration check valve opens, allowing the flow in the boom large chamber to return to the supply line of the second pump through the third boom valve core and the regeneration check valve, and flow to the small chamber of the stick cylinder, increasing the flow supply to the small chamber of the stick.

[0041] After receiving the command control signal, the flow dynamic shut-off valve performs logic control based on the boom outward swing pilot pressure and boom descent pilot pressure output by the eighth pilot valve and the third pilot valve.

[0042] Furthermore, the flow dynamic shut-off valve is logically controlled based on the boom outward swing pilot pressure and boom descent pilot pressure output by the eighth pilot valve and the third pilot valve, including:

[0043] The boom descent pilot pressure output by the third pilot valve connects the upper working position of the hydraulic pilot valve, causing the pilot pressure of the boom swinging outward to act on the right working position control port of the slide valve.

[0044] When the boom lifting pilot pressure is greater than the stick swing pilot pressure, the boom small chamber needs a flow supply. Under the action of the pilot pressure difference, the left working position of the slide valve is connected, so that the working oil output by the first pump flows to the boom small chamber through the flow dynamic shut-off valve and the right working position of the boom first valve core.

[0045] When the boom lifting pilot pressure is less than the stick swing pilot pressure, the boom chamber does not require the flow supply of the first pump. Under the action of the pilot pressure difference, the right working position of the slide valve is connected, and the oil supply from the first pump to the first valve core of the boom is cut off by the slide valve, so that more oil output from the first pump flows to the stick chamber.

[0046] The beneficial effects achieved by this invention are as follows:

[0047] This invention proposes a dynamic flow shut-off valve. During the combined action of boom descent and stick outward swing, the dynamic flow shut-off valve can proportionally shut off the oil supply from the first pump to the first valve core of the boom without impact. This not only allows more flow to the stick, accelerating the stick outward swing speed and improving operating efficiency, but also enables the first valve core of the boom to independently control the return oil and back pressure of the boom's large chamber, no longer controlling the oil inlet of the boom's small chamber. This avoids the defects of single valve core inlet and return valve port linkage control and increases the control flexibility of the system.

[0048] A flow regeneration system is proposed. During boom descent, the boom's inlet, return, and regeneration valves are independently controlled, improving system flexibility. Furthermore, during combined boom descent and other actuator actions such as the stick, the flow generated during boom descent can be directly regenerated and reused in the stick and other actuators, reducing the return flow during boom descent and minimizing throttling losses. Simultaneously, it increases the flow supply to the stick and other actuators, reduces pump output flow, accelerates actuator operation, and improves operational efficiency. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the flow regeneration hydraulic system according to the first embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram of a flow dynamic shut-off valve in the system;

[0051] Figure 3 This is a logic control method for a flow regeneration and utilization system.

[0052] 11 First pump; 12 Second pump; 13 Pilot pump; 14 Engine; 15 Fuel tank; 21 Boom cylinder; 22 Small chamber of boom cylinder; 23 Large chamber of boom cylinder; 31 First valve core of boom; 32 Second valve core of boom; 33 Third valve core of boom; 34 Fourth valve core of boom; 41~49 Pilot valve; 51 Flow dynamic shut-off valve; 52 Hydraulic pilot valve; 53 Spool valve; 54 Cone valve; 61 Stick cylinder; 62 Small chamber of stick cylinder; 63 Large chamber of stick cylinder; 7 Controller; 8 Operating handle; 91 First valve core of stick; 92 Second valve core of stick; 100 Regeneration check valve; 200 Replenishment check valve. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0054] This invention proposes a flow regeneration and utilization system for use in excavators, the schematic diagram of which is attached. Figure 1 As shown: Includes: a first pump 11; a second pump 12; a pilot pump 13; an engine 14; an oil tank 15; a boom cylinder 21; a first boom valve 31; a second boom valve 32; a third boom valve 33; a fourth boom valve 34; first to ninth pilot valves 41-49; a flow dynamic shut-off valve 51; a stick cylinder 61; a controller 7; an operating handle 8; a first stick valve 91; a second stick valve 92; a regeneration check valve 100; pressure sensors 103-104 for detecting and identifying working conditions; and supply lines connecting the actuator cylinders and various hydraulic valves.

[0055] The first pump 11, the second pump 12, and the pilot pump 13 are connected to the engine 14 and draw hydraulic oil from the oil tank 15. The oil output from the first pump 11 flows through the first pump supply line 101 to the flow dynamic shut-off valve 51, the first boom valve 31, the fourth boom valve 34, and the second stick valve 92, respectively. The oil output from the second pump 12 flows through the second supply line 102 to the second boom valve 32, the third boom valve 33, and the first stick valve 91, respectively. The oil output from the pilot pump 13 flows through the third supply line 103 to the first to ninth pilot valves 41 to 49, respectively.

[0056] The first pilot valve 41 is connected to the right working position control port 301 of the second valve core 32 of the boom via the first pilot oil pipe 401, controlling the confluence of the first pump 11 and the second pump 12 when the boom is raised; the second pilot valve 42 is connected to the left working position control port 302 of the first valve core of the boom via the second pilot oil pipe 402, controlling the boom raising; the third pilot valve 43 is connected to the right working position control port 303 of the first valve core 31 of the boom via the third pilot oil pipe 403, controlling the return oil and back pressure when the boom is lowered; the fourth pilot valve 44 is connected to the left working position control port 304 of the third valve core 33 of the boom via the fourth pilot oil pipe 404, controlling the regeneration flow from the large chamber to other actuators when the boom is lowered; the fifth pilot valve 45 is connected to the right working position control port 305 of the fourth valve core 34 of the boom via the fifth pilot oil pipe 405, controlling the return oil and back pressure when the boom is lowered. The sixth pilot valve 46 is connected to the left working position control port 306 of the first valve core of the boom via the sixth pilot oil pipe 406; the seventh pilot valve 47 is connected to the right working position control port 307 of the first valve core of the boom via the seventh pilot oil pipe 407; the eighth pilot valve 48 is connected to the left working position control port 308 of the second valve core of the boom via the eighth pilot oil pipe 408; the ninth pilot valve 49 is connected to the right working position control port 309 of the second valve core of the boom via the ninth pilot oil pipe 409; the flow dynamic shut-off valve 51 is connected in series with the first valve core of the boom via the oil pipe 501 and controls the oil supply of the first pump to the first valve core of the boom.

[0057] The flow dynamic shut-off valve 51 specifically includes: a hydraulically controlled pilot valve 52, a spool valve 53, control ports Pi1 and Pi2, an inlet port P1, and an outlet port P2. The upper working position control port Pi1 of the hydraulically controlled pilot valve 52 is connected to a pilot oil pipe 502, and is connected to the left working position control port of the spool valve 53 via a pilot oil pipe 503. It is also connected to the right working position control port of the first boom valve core 31 via a pilot oil pipe 504. The oil supply port Pi2 of the pilot valve 52 is connected to the left working position control port 308 of the second boom valve core 92 via a pilot oil pipe 408. The inlet port P1 of the spool valve 52 is connected to the first pump supply line 101, and the outlet port P2 of the spool valve 52 is connected to the inlet port of the first boom valve core 31 via an oil pipe 501.

[0058] The boom first valve core 31, boom second valve core 32, boom third valve core 33, and boom fourth valve core 34 are connected to the large chamber 23 of the boom cylinder via hydraulic lines 203 and to the small chamber 22 of the boom cylinder via hydraulic lines 202. The stick valve cores 91-92 are connected to the small chamber 62 of the stick cylinder via hydraulic lines 602 and to the large chamber 63 of the stick cylinder via hydraulic lines 603. The output signals from the first to ninth pilot valves 41-49, pressure sensors, handles, etc., all need to be processed and analyzed by the controller before being output.

[0059] In this flow regeneration system, the boom first valve core 31 and the flow dynamic shut-off valve 51 work together to form the following functions: when the boom is lowered, the right working position of the boom first valve core is connected, and the oil in the boom large chamber 23 returns to the oil tank through the right working position of the boom first valve core 31. At the same time, the flow dynamic shut-off valve 51 cuts off the oil supply from the first pump 11 to the boom first valve core according to the actual working conditions, so that the first boom valve core 31 only controls the return oil flow and back pressure of the boom large chamber 23.

[0060] The boom second valve core 32 and boom first valve core 31 cooperate to form the following functional structure: when the boom is lifted, the left working position of the boom first valve core is connected and the right working position of the boom second valve core is connected, so that the first pump 11 and the second pump 12 respectively supply oil to the boom large chamber 23, realizing the function of dual pump confluence and rapid boom lifting.

[0061] The third boom valve core 33, in conjunction with the regeneration check valve 100, has the following functions: when the boom is lowered, the third boom valve core operates in the left position, connecting the oil in the boom large chamber 23 with the second pump supply line 102. When the pressure in the boom large chamber 23 is higher than the pressure in the supply line 102, the regeneration check valve 100 opens, allowing the oil in the boom large chamber 23 to flow to the second supply line 102, and further to the boom stick and other actuators.

[0062] The boom fourth valve core 34, in conjunction with the oil replenishment valve 200, has the following functions: when the boom is lowered, the right working position of the boom fourth valve core 34 is connected, independently adjusting the return oil and back pressure of the boom large chamber 23, and replenishing oil to the boom small chamber 22 through the oil replenishment valve 200.

[0063] The flow dynamic shut-off valve 51 has the following structural functions: During the combined action of boom descent and stick outward swing, the upper working position of the hydraulic pilot valve 52 is connected, allowing the right working position control port of the slide valve 53 to connect with the left working position control port 308 of the second stick valve core 92 through the pilot oil pipe 408. When the pilot pressure output by the pilot valve 43 is greater than the output pilot pressure of the pilot valve 48, the slide valve 53 remains connected in the left working position, allowing the pump's output flow to flow to the first boom valve core 31. When the pressure in the pilot oil pipe 403 is less than that in the pilot oil pipe 408, the slide valve 52 can automatically achieve a non-impact proportional closure of the boom oil inlet according to the pilot pressure difference, allowing more of the first pump's flow to flow to the stick small chamber, accelerating the stick outward swing speed.

[0064] like Figure 1-3 As shown, a control method for a flow regeneration and utilization system includes:

[0065] The oil output from the first pump 11 flows through the first pump supply pipeline 101 to the flow dynamic shut-off valve 51, the first boom valve core 31, the fourth boom valve core 34, and the second stick valve core 92, respectively. The flow dynamic shut-off valve 51, the first boom valve core 31, and the fourth boom valve core 34 control the flow supply from the first pump 11 to the boom cylinder 21. The second stick valve core 92 controls the flow supply from the first pump 11 to the stick cylinder 61.

[0066] The oil output from the second pump 12 flows through the second pump supply pipeline 102 to the boom second valve core 32, boom third valve core 33, and stick first valve core 91, respectively. The boom second valve core 32 controls the flow rate supplied by the second pump 12 to the boom cylinder 21, while the boom third valve core 33 controls the flow rate regeneration from the boom large chamber 23 to the stick and other actuators. The stick first valve core 91 controls the oil supply from the second pump to the stick cylinder 61.

[0067] The oil output from pilot pump 13 flows through pilot supply line 103 to pilot valves 41-49 and pilot valve 52. Each pilot valve is connected to the control port of its corresponding control valve core via a pilot oil pipe. Specifically: the boom lifting control port 302 of the first boom valve core 31 is connected to pilot valve 42 via pilot oil pipe 402, and the boom lowering control port 303 is connected to pilot valve 43 via pilot oil pipe 403. The boom lifting control port 301 of the second boom valve core is connected to pilot valve 41 via pilot oil pipe 401. The flow regeneration control port 304 of the third boom valve core 33 is connected to pilot valve 44 via pilot oil pipe 404. The boom lowering control port 305 of the fourth boom valve core 34 is connected to pilot valve 45 via pilot oil pipe 405. The upper working position control port of the pilot valve 52 is connected to the pilot oil pipe 403 that controls the lowering of the boom, and the oil inlet is connected to the pilot oil pipe 408 that controls the outward swing of the stick.

[0068] In this embodiment, during the combined action of boom lowering and stick swinging, oil enters the small chamber 62 of the stick cylinder and returns oil to the large chamber 63. The flow dynamic shut-off valve 51 dynamically cuts off the oil supply from the first pump 11 to the first valve core 31 of the boom according to the actual working conditions, and further cuts off the oil supply to the small chamber 22 of the boom. The large chamber 23 of the boom cylinder returns oil through the first valve core 31 and the fourth valve core 34 of the boom, and regenerates it to other actuators through the third valve core 33 of the boom.

[0069] Specifically, when the operating handle 8 sends an operating command signal for lowering the boom and swinging the stick outward, it is transmitted to the controller 7. After analyzing and processing the operating command, the controller sends command control signals to the first to ninth pilot valves 41 to 49. Each pilot valve outputs the corresponding pilot pressure according to the input command signal and connects the corresponding working position of the valve core.

[0070] The pilot pressures output by the seventh pilot valve 47 and the eighth pilot valve 48 after receiving the command signal respectively cause the first valve core 91 of the stick to enter the right working position and the second valve core 92 of the stick to enter the left working position. Furthermore, the second pump supply line 102 and the first pump supply line 101 are connected to the small chamber 62 of the stick cylinder. At the same time, the oil in the large chamber 63 of the stick cylinder returns to the oil tank through the right working position of the first valve core 91 of the stick and the left working position of the second valve core 92 of the stick.

[0071] Furthermore, the pilot pressure output by the pilot valves 43 and 45 after receiving the received operation command causes the first valve core 31 and the fourth valve core 34 of the boom to enter the right working position, respectively, so that the oil inlet pipe 501 of the first control valve 31 of the boom is connected to the outlet P2 of the flow dynamic shut-off valve 51. At the same time, the oil in the large chamber 23 of the boom returns to the oil tank 15 through the right working position of the first valve core 31 and the fourth valve core 34 of the boom. When the pressure in the small chamber of the boom is lower than the opening pressure of the oil replenishment check valve 200, the oil replenishment check valve 200 replenishes oil to the small chamber 22 of the boom.

[0072] Furthermore, the pilot pressure output by the fourth pilot valve 44 after receiving the operation command causes the third valve core 33 of the boom to enter the left working position. This further connects the boom large chamber 23 with the pre-valve supply line 104 of the regeneration check valve 104. When the back pressure of the return oil in the boom large chamber 23 is greater than the pressure in the second pump supply line 102, the regeneration check valve 100 opens, allowing the flow in the boom large chamber 23 to return to the second pump supply line 102 through the third boom valve core 33 and the regeneration check valve 100, and further flow to the stick cylinder small chamber 62. This increases the flow supply to the stick cylinder small chamber 62, accelerates the outward swing speed of the stick cylinder, and improves the operating efficiency. At the same time, it reduces the working circulation of the oil and the output flow of the second pump 12, thus reducing the power consumption of the pump.

[0073] After receiving the command control signal, the flow dynamic shut-off valve 51 performs the following operations based on the boom outward swing pilot pressure and boom descent pilot pressure output by the eighth pilot valve 48 and the third pilot valve 43: Figure 3The logic control is as shown. Specifically, the boom descent pilot pressure output by the third pilot valve 43 connects the upper working position of the second pilot valve 52, further causing the boom outward swing pilot pressure to act on the right working position control port of the spool valve 53. When the boom lifting pilot pressure is greater than the boom outward swing pilot pressure, the boom descent speed is faster, and the boom cavity requires flow supply. Under the action of the pilot pressure difference, the left working position of the spool valve 53 is connected, allowing the working oil output by the first pump 11 to flow to the boom cavity through the flow dynamic shut-off valve 51 and the right working position of the first boom valve core. When the boom lifting pilot pressure is less than the boom outward swing pilot pressure, the boom descent is slower and can rely entirely on potential energy for descent. The cavity does not require flow supply from the first pump. Under the action of the pilot pressure difference, the right working position of the spool valve 53 is connected, and the oil supply from the first pump 11 to the first boom valve core is cut off by the spool valve 53, causing more oil output by the first pump to flow to the boom cavity, thus accelerating the boom outward swing speed. Improve work efficiency.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A flow dynamic shut-off valve, characterized in that, include: Hydraulic pilot valve (52), slide valve (53), first control port Pi1 and second control port Pi2, inlet port P1 and outlet port P2; The first control port Pi1 is connected to the left working position control port of the slide valve (53) and the upper working position control port of the hydraulic pilot valve (52); the second control port Pi2 is connected to the oil inlet of the hydraulic pilot valve (52). The oil inlet P1 is connected to the oil inlet of the slide valve (53); the oil outlet P2 is connected to the oil outlet of the slide valve (53); The first control port Pi1 is connected to the boom lowering pilot oil pipe, and the second control port Pi2 is connected to the pilot oil pipes of other actuators. The control oil output from the first control port Pi1 and the second control port Pi2 controls the hydraulic pressure difference of the slide valve (53) in the left working position and the right working position, controls the valve port area of ​​the slide valve (53), and controls the flow rate of the oil in the slide valve (53) from the inlet port P1 to the outlet port P2 according to the valve port area.

2. The flow dynamic shut-off valve according to claim 1, characterized in that, The switching method of the slide valve (53) adopts hydraulic differential pressure ratio switching.

3. A flow regeneration and utilization system, characterized in that, include: First pump (11), second pump (12), pilot pump (13), engine (14), oil tank (15), boom cylinder (21), boom first valve core (31), boom second valve core (32), boom third valve core (33), boom fourth valve core (34), first to ninth pilot valves (41 to 49), flow dynamic shut-off valve (51) as described in any one of claims 1-2, other actuator first valve core, other actuator second valve core, regeneration check valve (100), supply pipeline connecting actuator cylinder and each hydraulic valve; The first pump (11), the second pump (12), and the pilot pump (13) are connected to the engine (14) and draw out the hydraulic oil from the oil tank (15); The oil output by the first pump (11) flows through the first pump supply pipeline (101) to the flow dynamic shut-off valve (51), the first valve core of the boom (31), the fourth valve core of the boom (34), and the second valve core of other actuators respectively. The oil output by the second pump (12) flows through the second pump supply pipeline (102) to the second valve core (32) of the boom, the third valve core (33) of the boom, and the first valve core of other actuators respectively; The oil output by the pilot pump (13) flows through the third pump supply pipeline (103) to the first to ninth pilot valves (41 to 49). The first pilot valve (41) is connected to the right working position control port (301) of the second valve core (32) of the boom through the first pilot oil pipe (401) to control the confluence of the first pump (11) and the second pump (12) when the boom is lifted; The second pilot valve (42) is connected to the left working position control port (302) of the first valve core (31) of the boom via the second pilot oil pipe (402) to control the boom lifting; The third pilot valve (43) is connected to the right working position control port (303) of the first valve core (31) of the boom via the third pilot oil pipe (403) to control the boom descent return oil and back pressure; The fourth pilot valve (44) is connected to the left working position control port (304) of the third valve core (33) of the boom through the fourth pilot oil pipe (404) to control the regeneration flow from the large chamber to other actuators when the boom descends; The fifth pilot valve (45) is connected to the right working position control port (305) of the fourth valve core (34) of the boom via the fifth pilot oil pipe (405) to control the return oil and back pressure of the boom descent; The sixth pilot valve (46) is connected to the left working position control port (306) of the first valve core of other actuators via the sixth pilot oil pipe (406); The seventh pilot valve (47) is connected to the right working position control port (307) of the first valve core of other actuators via the seventh pilot oil pipe (407); The eighth pilot valve (48) is connected to the left working position control port (308) of the second valve core of other actuators via the eighth pilot oil pipe (408); The ninth pilot valve (49) is connected to the right working position control port (309) of the second valve core of other actuators via the ninth pilot oil pipe (409); The flow dynamic shut-off valve (51) is connected in series with the boom first valve core (31) through the oil pipe (501) and controls the first pump (11) to supply oil to the boom first valve core (31).

4. The flow regeneration and utilization system according to claim 3, characterized in that, The other actuators include the boom.

5. The flow regeneration and utilization system according to claim 4, characterized in that, Also includes: Other actuator cylinders (61) are connected to other actuators.

6. The flow regeneration and utilization system according to claim 5, characterized in that, Also includes: Pressure sensor, operating handle (8) and controller (7); Pressure sensors are used to detect and identify operating conditions; The operating handle (8) is used to issue operating command signals for lowering the boom and swinging the stick outward; The controller (7) is used to receive the output signals from the pressure sensor and the handle, process and analyze them, and then send command control signals to the first to ninth pilot valves (41 to 49). Each pilot valve outputs the corresponding pilot pressure according to the input command control signal and connects the corresponding working position of the valve core.

7. An excavator, characterized in that, Includes the flow regeneration and utilization system according to any one of claims 3-6.

8. A control method for the flow regeneration and utilization system according to claim 6, characterized in that, include: When the boom lowers and the stick swings outwards in a combined action, oil enters the small chamber (62) of the stick cylinder and returns oil to the large chamber (63). The flow dynamic shut-off valve (51) dynamically shuts off the oil supply from the first pump (11) to the first valve core (31) of the boom according to the actual working conditions, and further shuts off the oil supply from the small chamber (22) of the boom. The large chamber (23) of the boom returns oil through the first valve core (31) and the fourth valve core (34) of the boom, and is regenerated to the stick through the third valve core (33) of the boom.

9. The control method according to claim 8, characterized in that, The process of the combined action of boom lowering and stick swing includes: When the operating handle (8) sends the operating command signal for boom lowering and stick swinging outward, it is transmitted to the controller (7). The controller analyzes and processes the operating command signal and sends the command control signal to the first to ninth pilot valves (41 to 49). Each pilot valve outputs the corresponding pilot pressure according to the input command control signal and connects the corresponding working position of the valve core. After receiving the command control signal, the pilot pressure output by the seventh pilot valve (47) and the eighth pilot valve (48) respectively causes the first valve core (91) of the stick to enter the right working position and the second valve core (92) of the stick to enter the left working position, so that the second pump supply line (102) and the first pump supply line (101) are connected to the small chamber (62) of the stick cylinder. At the same time, the oil in the large chamber (63) of the stick cylinder returns to the oil tank through the right working position of the first valve core (91) of the stick and the left working position of the second valve core (92). After receiving the command control signal, the pilot pressure output by the third pilot valve (43) and the fifth pilot valve (45) respectively causes the first valve core (31) and the fourth valve core (34) of the boom to enter the right working position, so that the oil pipe (501) of the first valve core (31) of the boom is connected to the outlet P2 of the flow dynamic shut-off valve (51). At the same time, the oil in the large chamber (23) of the boom returns to the oil tank (15) through the right working position of the first valve core (31) and the fourth valve core (34) of the boom. When the pressure in the small chamber of the boom is lower than the opening pressure of the oil replenishment check valve (200), the oil replenishment check valve (200) replenishes oil to the small chamber (22) of the boom. After receiving the command control signal, the fourth pilot valve (44) outputs pilot pressure, which causes the boom third valve core (33) to enter the left working position, so that the boom large chamber (23) is connected to the valve front supply line (104) of the regeneration check valve (100). When the return oil back pressure of the boom large chamber (23) is greater than the pressure of the second pump supply line (102), the regeneration check valve (100) opens, so that the flow in the boom large chamber (23) returns to the second pump supply line (102) through the boom third valve core (33) and the regeneration check valve (100), and flows to the stick cylinder small chamber (62), increasing the flow supply to the stick cylinder small chamber (62). After receiving the command control signal, the flow dynamic shut-off valve (51) performs logic control based on the boom swing pilot pressure and boom descent pilot pressure output by the eighth pilot valve (48) and the third pilot valve (43).

10. The control method according to claim 9, characterized in that, The flow dynamic shut-off valve (51) is logically controlled based on the boom swing pilot pressure and boom descent pilot pressure output by the eighth pilot valve (48) and the third pilot valve (43), including: The boom descent pilot pressure output by the third pilot valve (43) connects the upper working position of the hydraulic pilot valve (52), so that the pilot pressure of the boom swinging outward acts on the right working position control port of the slide valve (53). When the boom lifting pilot pressure is greater than the stick swing pilot pressure, the boom small cavity needs flow supply. Under the action of the pilot pressure difference, the left working position of the slide valve (53) is connected, so that the working oil output by the first pump (11) flows to the boom small cavity through the flow dynamic shut-off valve (51) and the right working position of the boom first valve core. When the boom lifting pilot pressure is less than the stick swing pilot pressure, the boom small chamber does not need the flow supply of the first pump (11). Under the action of the pilot pressure difference, the right working position of the slide valve (53) is connected, and the oil supply from the first pump (11) to the first valve core of the boom is cut off by the slide valve (53), so that more oil output from the first pump flows to the stick cylinder small chamber.

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