Secondary pilot pressure random reconstruction system for unloading oil way of core-opening multi-way valve

Abstract

The invention discloses an open-core multi-way valve unloading oil way secondary pilot pressure random reconstruction system which comprises a multi-way valve and an unloading valve set, and the multi-way valve comprises a plurality of reversing valves, proportional valves and pressure reducing valves; the unloading valve group comprises an active unloading valve, an electromagnetic valve and a pressure reducing valve in the multi-way valve; according to the system, an active unloading valve of a special structure is connected to the tail end of an unloading oil way in series, the active unloading valve is in a conducting state under the normal condition, a back containing cavity of the active unloading valve is communicated with an oil return cavity, hydraulic oil in the back containing cavity has no pressure, the active unloading valve is opened, and the active unloading valve is in a nearly-flat zero-pressure conducting state; the multi-way valve hydraulic system is in nearly zero-pressure unloading; under the condition that electric signals are input, communication between the back containing cavity of the active unloading valve and the oil return cavity is disconnected, pressure is built in the back containing cavity, the valve element moves towards the closed state and stops moving after balance, pilot pressure is built in the whole hydraulic system, and the energy level state capable of recovering operation is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to a multi-way valve, in particular to a secondary pilot pressure random reconstruction system of an unloading oil circuit of an open core multi-way valve. BACKGROUND

[0002] The multi-way valve constituting an open core hydraulic system usually has a logic structure with a hydraulic oil unloading function in the middle position, which nearly zero pressure unloads the hydraulic oil to the oil return tank. This design has defects. Once each circuit returns to the middle position, the energy of the hydraulic system is in a low energy state. Without external mechanical action, there is no other way to restore the system to a working state, i.e. a high energy state.

[0003] In order to solve this problem, the usual method is to connect a back pressure valve in series on the middle unloading circuit, so that the unloading return pressure of the hydraulic system changes from nearly zero pressure to a pressure that can start the hydraulic system, usually several MPa. In this way, the entire hydraulic system cannot be unloaded at nearly zero pressure when not working, but is unloaded at a pressure of several MPa, so-called pressure unloading. As a result, it brings heat and non-normal energy consumption and inefficient consumption of resources. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a secondary pilot pressure random reconstruction system of an unloading oil circuit of an open core multi-way valve.

[0005] To solve the above technical problems, the technical scheme of the present application is: a secondary pilot pressure random reconstruction system of an unloading oil circuit of an open core multi-way valve, characterized in that: it comprises a multi-way valve arranged on a main oil circuit and an unloading valve group arranged at the end of an unloading oil circuit of the multi-way valve; the multi-way valve comprises a plurality of directional valves, a proportional valve for controlling the action of the directional valves, and a pressure reducing valve arranged between the main oil circuit and the proportional valve; The unloading valve group comprises an active unloading valve, a solenoid valve, and a pressure reducing valve in the multi-way valve; the active unloading valve comprises an oil inlet P3, a working port A3, and a return port T3, the oil inlet P3 is connected to the end of the unloading oil circuit of the multi-way valve, the return port T3 is connected to the oil return tank, the active unloading valve is provided with a back cavity, the working port A3 is in communication with the back cavity, and the oil inlet P3 is also in communication with the back cavity through a throttle; the solenoid valve comprises an oil inlet P2, a working port A2, and a return port T2, the return port T2 is connected to the oil return tank, the working port A2 is in communication with the working port A3, and the pressure reducing valve comprises a working port A1 and an oil inlet P1, the working port A1 is in communication with the oil inlet P2, and the oil inlet P1 is connected to the system pressure oil circuit; When the electromagnetic valve is not powered, the oil passage between the working port A2 and the oil return port T2 is communicated, the back cavity is communicated with the oil return tank through the working port A3, the working port A2 and the oil return port T2, the back cavity can be unloaded through the electromagnetic valve, at this time the active unloading valve is fully opened, the oil passage between the oil inlet port P3 and the oil return port T3 is fully communicated for zero pressure unloading; When the electromagnetic valve is powered, the oil passage between the working port A2 and the oil inlet port P2 is connected, and the constant pressure oil liquid after pressure reduction through the pressure reducing valve establishes back pressure in the back cavity, the active unloading valve gradually partially closes, and the oil passage between the oil inlet port P3 and the oil return port T3 is partially connected for low pressure unloading.

[0006] As a preferred technical solution, the unloading valve group is connected to the end of the middle unloading oil passage or the end of the pressure oil passage of the multi-way valve.

[0007] As a preferred technical solution, the active unloading valve comprises a valve body one, the oil inlet port P3 is arranged at the head end of the valve body one, the oil return port T3 is arranged at the side of the valve body one, a valve core one is slidably arranged in the valve body one, the valve core one can communicate or cut off the oil passage between the oil inlet port P3 and the oil return port T3 by sliding along the valve body one, and the back cavity is arranged at the tail end of the valve core one.

[0008] As a preferred technical solution, the electromagnetic valve is a two-position three-way electromagnetic valve or a two-position four-way electromagnetic valve.

[0009] As a preferred technical solution, the active unloading valve and the two-position three-way electromagnetic valve are separately arranged, the two-position three-way electromagnetic valve comprises an oil inlet port P2, a working port A2 and an oil return port T2, the two-position three-way electromagnetic valve further comprises a valve body two, the valve body two is further provided with an oil port A communicated with the working port A2, an oil port B communicated with the oil return port T2 and an oil port C communicated with the oil inlet port P2, and a valve core two is slidably arranged in the valve body two, the valve core two slides to alternately connect and disconnect the oil passage between the oil port A and the oil port B and the oil passage between the oil port A and the oil port C. Or the active unloading valve and the two-position three-way electromagnetic valve are integrated, the two-position three-way electromagnetic valve comprises a valve body two, the valve body two is inserted and fixed in the valve body one, and the head of the valve body two is sealingly inserted into the back cavity of the valve core one, the valve body two is provided with an oil port B communicated with the oil return port T2 and an oil port C communicated with the oil inlet port P2, a valve core two is slidably arranged in the valve body two, the valve core two is provided with an oil port A communicated with the working port A2, the valve core two slides to alternately connect and disconnect the oil passage between the oil port A and the oil port B and the oil passage between the oil port A and the oil port C, and the working port A2 is arranged in the valve body two and communicated with the back cavity.

[0010] As a preferred technical scheme, the two-position four-way electromagnetic valve comprises an oil inlet P2, a working port A2, an oil return port T2 and an oil return port T4, the oil return port T4 is connected to an oil return tank, the two-position four-way electromagnetic valve comprises a valve body two, the valve body two is further provided with an oil port A in communication with the working port A2, an oil port B in communication with the oil return port T2, an oil port C in communication with the oil inlet P2, and an oil port D in communication with the oil return port T4, and a valve core two is slidably arranged in the valve body two, and the valve core two alternately opens and closes the oil paths between the oil port A and the oil port B, the oil path between the oil port A and the oil port C, and the oil path between the oil port C and the oil port D.

[0011] As a preferred technical scheme, the throttle port is arranged on the valve core one to communicate the oil inlet P3 and the back cavity inside the active unloading valve.

[0012] As a preferred technical scheme, the throttle port is arranged on the valve core one to communicate the oil inlet P3 and the back cavity inside the active unloading valve.

[0013] As a preferred technical scheme, the pressure reducing valve is an overflow pressure reducing valve, the working port A1 is provided with one end of the valve body three, the oil inlet P1 and the oil return port T1 are arranged on the side of the valve body three, and the oil inlet P1 is close to the working port A1, the valve body three is slidably arranged with a valve core three, the head end of the valve core three corresponds to the working port A1, and the valve core three can switch the oil paths between the oil inlet P1 and the working port A1 or the oil paths between the oil inlet P1 and the oil return port T1 by sliding in the valve body three.

[0014] As a preferred technical scheme, the pressure reducing valve and the electromagnetic valve are further provided with an overflow valve.

[0015] The beneficial effects of the present application are as follows: the system is connected with a special structure of active unloading valve at the end of unloading oil way, the active unloading valve is in the conducting state under normal conditions, the back cavity of the active unloading valve is connected with the oil return cavity, the hydraulic oil in the back cavity has no pressure, the active unloading valve is opened, the active unloading valve is in the near zero pressure conducting state, and the multi-way valve hydraulic system is in the near zero pressure unloading; under the condition of electric signal input, the active unloading valve is in the unloading state, and part of the oil continues to enter the back cavity of the active unloading valve through the throttle, at this time, the oil after pressure reduction enters the back cavity, the pressure is established in the back cavity of the active unloading valve, the spool moves to the closed state, stops moving after balancing, the pilot pressure of the whole hydraulic system is established, and the energy state capable of recovering operation is obtained; if no work is needed, the electric signal is cancelled, the back cavity of the active unloading valve is connected with the oil return cavity, the hydraulic oil in the back cavity has no pressure, the active unloading valve is opened, the active unloading valve is in the near zero pressure conducting state, and the hydraulic system is in the near zero pressure unloading. BRIEF DESCRIPTION OF DRAWINGS

[0016] The following drawings are only intended to illustrate and explain the present application, and do not limit the scope of the present application. Among them: Figure 1 is the system principle diagram of the embodiment one of the present application; Figure 2 is the principle diagram of the unloading valve group of the embodiment one of the present application; Figure 3 is the structure diagram of the unloading valve group of the embodiment one of the present application; Figure 4 is the structure diagram of the active unloading valve of the embodiment one of the present application; Figure 5 is the structure diagram of the pressure reducing valve of the embodiment one of the present application; Figure 6 is a structure principle diagram of the two-position three-way electromagnetic valve of the embodiment one of the present application; Figure 7 is another structure principle diagram of the two-position three-way electromagnetic valve of the embodiment one of the present application; Figure 8 is the structure diagram of the active unloading valve of the embodiment two of the present application; Figure 9 is the principle diagram of the unloading valve group of the embodiment two of the present application; Figure 10 is the structure diagram of the unloading valve group of the embodiment three of the present application; Figure 11 is the structure diagram of the unloading valve group of the embodiment four of the present application; Figure 12 is Figure 11 is the enlarged view of A in the figure; Figure 13 is the structure diagram of the unloading valve group of the embodiment five of the present application; Figure 14 is the principle diagram of the unloading valve group of the embodiment six of the present application; Figure 15 is the principle diagram of the unloading valve group of the embodiment seven of the present application; Figure 16 is the principle diagram of the unloading valve group of the embodiment eight of the present application; Figure 17 is the system principle diagram of the embodiment nine of the present application; Figure 18 is the principle diagram of the unloading valve group of the embodiment nine of the present application;Figure 19 This is a schematic diagram of the unloading valve assembly in Embodiment 10 of the present invention; Figure 20 This is a schematic diagram of the unloading valve assembly in Embodiment Eleven of the present invention; Figure 21 This is a schematic diagram of the unloading valve assembly of Embodiment Twelve of the present invention; Figure 22 This is a structural diagram of the unloading valve assembly of Embodiment Twelve of the present invention; Figure 23 yes Figure 22 Enlarged view of point B in the middle; Figure 24 This is a schematic diagram of the unloading valve assembly according to Embodiment Thirteen of the present invention; Figure 25 This is a schematic diagram of the unloading valve assembly in Embodiment Fourteen of the present invention; Figure 26 This is a schematic diagram of the unloading valve assembly of Embodiment 15 of the present invention; Figure 27 This is a schematic diagram of the unloading valve assembly of Embodiment Sixteen of the present invention; Figure 28 This is a schematic diagram of the unloading valve assembly of Embodiment Seventeen of the present invention; Figure 29 This is a schematic diagram of the unloading valve assembly of Embodiment 18 of the present invention; Figure 30 This is a schematic diagram of the unloading valve assembly of Embodiment Nineteen of the present invention; In the diagram: 100 - Directional control valve; 200 - Proportional valve; 300 - Pressure reducing valve; 301 - Valve body three; 302 - Valve core three; 303 - Spring two; 400 - Active unloading valve; 401 - Valve body one; 402 - Valve core one; 403 - Back cavity; 404 - Throttling port; 405 - Spring one; 500 - Solenoid valve; 501 - Valve body two; 502 - Port A; 503 - Port B; 504 - Valve core two; 505 - Port C; 507 - Oil passage two; 506 - Oil passage one; 508 - Oil passage three; 509 - Port D; 600 - Relief valve. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the following detailed description, only certain exemplary embodiments of the invention are described by way of illustration. Undoubtedly, those skilled in the art will recognize that various modifications can be made to the described embodiments without departing from the spirit and scope of the invention. Therefore, the drawings and description are illustrative in nature and not intended to limit the scope of the claims.

[0018] Example 1: As Figure 1 and Figure 2 As shown, the open-heart multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system includes a multi-way valve installed on the main oil circuit and an unloading valve group located at the end of the unloading oil circuit in the middle position of the multi-way valve.

[0019] The multi-way valve comprises several reversing valves 100, a proportional valve 200 for controlling the action of the reversing valves 100, and a pressure reducing valve 300 arranged between the main oil circuit and the proportional valve 200. The multi-way valve is a multi-way valve with an open center system commonly used in the prior art, and the structural principle is described in detail in Figure 1 The pressure reducing valve 300 is connected to the multi-way valve system pressure oil circuit, and can provide pilot oil for the proportional valve 200, and provide energy for the switching of the reversing valve 100.

[0020] Referring to Figure 2 and Figure 3 The unloading valve group comprises an active unloading valve 400, a solenoid valve 500, and a pressure reducing valve 300 in the multi-way valve. In this embodiment, the solenoid valve 500 is a two-position three-way solenoid valve, the active unloading valve 400 is arranged separately from the two-position three-way solenoid valve, and is fixed on the valve seat of the multi-way valve. The pressure reducing valve 300 is an overflow pressure reducing valve.

[0021] Referring to Figure 3 The active unloading valve comprises an oil inlet P3, a working port A3, and an oil return port T3. The oil inlet P3 of the active unloading valve 400 is connected to the end of the neutral unloading oil circuit of the multi-way valve. The oil return port T3 of the active unloading valve 400 is connected to the oil return tank. The two-position three-way solenoid valve comprises an oil inlet P2, a working port A2, and an oil return port T2. The working port A3 of the active unloading valve 400 is connected to the working port A2 of the two-position three-way solenoid valve. The oil return port T2 of the two-position three-way solenoid valve is connected to the oil return tank. The pressure reducing valve comprises a working port A1, an oil inlet P1, and an oil return port T1. The working port A1 is in communication with the oil inlet P2. The oil inlet P1 is connected to the system pressure oil circuit. The oil return port T1 is connected to the oil return tank. When the solenoid valve 500 is not powered, the oil circuit between the working port A2 and the oil return port T2 is in communication, the back cavity is communicated with the oil return tank through the working port A3, the working port A2, and the oil return port T2, the back cavity can be unloaded by the solenoid valve 500, at this time, the active unloading valve is fully opened, and the oil circuit between the oil inlet P3 and the oil return port T3 is fully communicated for zero-pressure unloading. When the solenoid valve 500 is powered, the oil circuit between the working port A2 and the oil inlet P2 is connected, and the constant-pressure oil liquid after pressure reduction by the pressure reducing valve 300 establishes back pressure in the back cavity. The active unloading valve is gradually partially closed, and the oil circuit between the oil inlet P3 and the oil return port T3 is partially communicated for low-pressure unloading.

[0022] Referring to Figure 4The active unloading valve 400 comprises a valve body 401, the oil inlet P3 is arranged at one end of the valve body 401, the oil return port T3 and the working port A3 are arranged at the side of the valve body 401, and the oil return port T3 is close to the side of the oil inlet P3, a valve core 402 is slidably arranged in the valve body 401, the head end of the valve core 402 corresponds to the oil inlet P3, the valve core 402 can communicate or cut off the oil path between the oil inlet P3 and the oil return port T3 by sliding along the valve body 401, the tail end of the valve core 402 is provided with a back cavity 403 which communicates with the working port A3, a spring 405 for controlling the sliding of the valve core 402 is arranged in the back cavity 403, and the two ends of the spring 405 abut against the valve core 402 and the valve body 401 respectively, a throttle port 404 which communicates the oil inlet P3 with the back cavity 403 is further arranged on the valve body 401, and the throttle port 404 is arranged on the valve core 402 to communicate the oil inlet P3 with the back cavity 403 in the active unloading valve 400. Of course, the spring can also not be arranged in the back cavity 403, which is also within the protection scope of the patent.

[0023] Referring to Figure 4 The two-position three-way electromagnetic valve and the active unloading valve 400 are arranged separately. The two-position three-way electromagnetic valve comprises an oil inlet P2, a working port A2 and an oil return port T2, and further comprises a valve body 501, an oil port A502 which communicates with the working port A2, an oil port B503 which communicates with the oil return port T2, and an oil port C505 which communicates with the oil inlet P2 are further arranged on the valve body 501, and a valve core 504 is slidably arranged in the valve body 501, the valve core 504 alternately opens and closes the oil path between the oil port A502 and the oil port B503 and the oil path between the oil port A502 and the oil port C505, when the two-position three-way electromagnetic valve is not powered, the working port A2 communicates with the oil return port T2, and the working port A2 is disconnected with the oil inlet P2; when the two-position three-way electromagnetic valve is powered, the working port A2 communicates with the oil inlet P2, and the working port A2 is disconnected with the oil return port T2.

[0024] When the two-position three-way electromagnetic valve is powered, the oil path of the working port A2 to the oil return port T2 is disconnected, and two structure forms can be realized: one is shown in Figure 6 When the electromagnetic valve 500 is in the right position, the oil in the working port A2 cannot flow to the oil return port T2, and the working port A2 communicates with the oil inlet P2; the other is shown in Figure 7 When the electromagnetic valve 500 is in the right position, the working port A2 is disconnected with the oil return port T2, and the working port A2 communicates with the oil inlet P2.

[0025] At this time, the pressure established by the whole system is the system pressure of the hydraulic system, which is very high. In fact, such high pressure is not needed at this time, and such high pressure will generate heat, energy, system resource consumption and other energy waste. To solve this problem, the hydraulic oil through pressure when the active unloading valve 400 is closed can be set. The method is to connect a pressure reducing valve 300, i.e. a pressure limiting valve, to the back cavity 403 of the active unloading valve 400.

[0026] Referring to Figure 5 , the pressure reducing valve 300 is an overflow pressure reducing valve, which comprises a valve body three 301, the working port A1 is provided at one end of the valve body three 301, the oil inlet port P1 and the oil return port T1 are arranged on the side of the valve body three 301, and the oil inlet port P1 is close to the working port A1, a valve core three 302 is slidably arranged in the valve body three 301, the head end of the valve core three 302 corresponds to the working port A1, a spring two 303 is arranged in the tail end valve cavity of the valve core three 302, and the valve core three 302 can switch the oil passage between the oil inlet port P1 and the working port A1 or the oil passage between the oil inlet port P1 and the oil return port T1 along the valve body three 301. A throttle port is arranged in the valve core three 302, the oil inlet port P1 and the working port A1 are kept in communication, as the pressure of the oil inlet port P1 continuously rises, the pressure acting on the working port A1 also rises, the force on the cross-sectional area of the valve core three 302 is also increased, the valve core three 302 continuously overcomes the spring force and gradually moves up, and the area of the throttle port 404 on the valve core three 302 gradually decreases. When it rises to a certain pressure value, the valve core three 302 moves up to realize the communication between the working port A1 and the oil return port T1, and the throttle port of the oil inlet port P1 to the working port A1 becomes smaller, so that the pressure of the oil inlet port P1 will not rise with the rise of the pressure of the oil inlet port P1, and the overload overflow is realized, and the working port A1 is in a constant pressure state. The two-way flow is the feature of the overflow pressure reducing valve, which retains the characteristics of converting high-pressure oil into low-pressure oil and the function of the overflow valve. If the pressure reducing valve 300 is not set, the system pressure will directly act on the oil inlet port P2 of the two-position three-way electromagnetic valve, and the pressure at this time is relatively high.

[0027] The working principle of the embodiment is as follows: When the two-position three-way electromagnetic valve is not powered, referring to Figure 2When the two-position three-way electromagnetic valve is in the left position, the working port A2 is in communication with the oil return port T2, and the working port A2 is disconnected from the oil inlet port P2. The back cavity 403 is in communication with the oil return tank through the working port A3, the working port A2 and the oil return port T2. When the oil inlet port P3 is filled with oil, part of the hydraulic oil in the oil inlet port P3 flows to the back cavity 403 and the working port A3 through the throttle port 404 of the valve core one 402, and is unloaded through the two-position three-way electromagnetic valve. No pressure can be established in the back cavity 403. When the pressure in the oil inlet port P3 is high, the valve core one 402 is pushed upward against the elastic force of the spring one 405 (when there is no spring one 405, the elastic force of the spring one 405 does not need to be overcome), and the oil passage between the oil inlet port P3 and the oil return port T3 is opened through the valve core one 402. Hydraulic oil flows from the oil inlet port P3 to the oil return port T3 for unloading. At this time, the active unloading valve 400 is in a nearly zero-pressure conduction state, and the hydraulic system is nearly zero-pressure unloaded. When the two-position three-way electromagnetic valve is energized, referring to Figure 2 When the two-position three-way electromagnetic valve is in the right position, the working port A2 is in communication with the oil inlet port P2, and the working port A2 is disconnected from the oil return port T2. The back cavity 403 is in communication with the working port A1 through the working port A3, the working port A2 and the oil inlet port P2. The oil after pressure reduction in the pressure reducing valve 300 enters the oil inlet port P2. At this time, the working port A3 is in a back pressure state. After the oil inlet port P3 is filled with oil, part of the hydraulic oil in the oil inlet port P3 flows to the back cavity 403 through the throttle port 404 of the valve core one 402. At this time, the oil inlet port P2 is in communication with the working port A2, so that back pressure is formed on the working port A3. The active unloading valve is unloaded at the same time, and part of the oil continues to enter the back cavity 403 of the active unloading valve through the throttle port. At this time, the oil after pressure reduction enters the back cavity 403, so that the pressure in the back cavity 403 is accumulated. Under the spring force of the spring one 405 and the pressure difference (due to the area difference), the back cavity 403 can push the valve core one 402 downward, so that the valve core one 402 moves in the closing direction. When the unloading force and the force in the back cavity 403 are equal, the pressure on both sides tends to be balanced, and the valve core stops moving. At this time, the pilot pressure of the entire hydraulic system is established.

[0028] The system is connected with a special structure of active unloading valve at the end of the middle unloading oil path. When each hydraulic sub-circuit is not working, the T port of two-position three-way electromagnetic valve connected with the active unloading valve is in the conductive state, at this time the valve core one 402 of the active unloading valve is in the open state under the action of oil in the P3 port oil path, so that the multi-way valve is in the nearly zero pressure unloading. When any hydraulic sub-circuit is working, the control signal is input into the two-position three-way electromagnetic valve, so that the oil path connected with the pressure reducing valve 300 and the control end of the active unloading valve is in the conductive state, and the control end of the active unloading valve is under the pressure control of the pressure reducing valve 300. The pressure after the pressure reducing limits the total pressure of the oil source unloading valve control cavity. Since the oil after pressure reduction enters the back cavity of the active unloading valve, and the oil in the P3 port oil path enters the back cavity of the active unloading valve through the throttle port of the active unloading valve, the two oils together establish back pressure in the back cavity, so that the valve core one 402 of the active unloading valve gradually closes, and the throttle pressure of the valve port of the valve core one 402 of the active unloading valve gradually increases. When the throttle pressure increases to a certain extent, the pressure controlled by the back cavity of the active unloading valve will balance with the throttle pressure formed by the valve core one 402 of the active unloading valve on the P3 oil path, and the valve core stops moving. The valve core one 402 of the active unloading valve is unloaded under the balanced pressure, forming a low pressure unloading system controlled by the pilot pressure reducing valve 300, so that the whole hydraulic system establishes a pilot pressure and a low pressure operation system, and has the ability to restore the operating potential state. If it is not needed to work, the electric signal will be cancelled, the back cavity of the active unloading valve is in the release state, the hydraulic oil of the back cavity has no pressure, the active unloading valve is opened, and the active unloading valve is in the nearly zero pressure conductive state, and the hydraulic system is nearly zero pressure unloading.

[0029] The end of the middle unloading oil path and the end of the pressure oil path both belong to the unloading oil path end of the multi-way valve. In embodiment one, the end of the middle unloading oil path belongs to one kind of unloading oil path end, and the end of the pressure oil path in embodiment nine belongs to another kind of unloading oil path end.

[0030] Embodiment two: the structure of this embodiment is basically the same as that of embodiment one, and the difference mainly lies in that the throttle port 404 of the active unloading valve 400 is located differently. In embodiment one, the liquid resistance valve internal connection structure is that a small diameter throttle port 404 is processed inside the valve core one 402 of the active unloading valve 400. In embodiment two, the liquid resistance valve external connection structure refers to that the throttle port 404 is arranged on the valve seat outside the valve body one 401 to communicate the oil inlet P3 and the back cavity outside the active unloading valve 400. The throttle port 404 can be directly cast or processed with a small diameter oil path on the valve seat, and at this time the working principle is basically the same as that of embodiment one. Figure 8 and Figure 9 The throttle port 404 can be directly cast or processed with a small diameter oil path on the valve seat, and at this time the working principle is basically the same as that of embodiment one.

[0031] Embodiment three: the structure of this embodiment is basically the same as that of embodiment one, the difference mainly lies in the structure of the active unloading valve. See Figure 10 In this embodiment, the structure of the valve body one 401 is cancelled, the valve core one 402 is directly slidably installed on the valve seat of the multi-way valve, and the spring one 405 is installed between the valve core one 402 and the valve body. The working principle at this time is the same as that of embodiment one. Of course, the spring one 405 can also not be arranged in the back cavity 403, which is also within the protection scope of this patent, and the working principle at this time is the same as that of embodiment one.

[0032] Embodiment four: the structure of this embodiment is basically the same as that of embodiment one, the difference mainly lies in that the two-position three-way electromagnetic valve and the active unloading valve 400 are fixed in one body to form an integrated structure, and the two-position three-way electromagnetic valve is arranged at the tail end of the active unloading valve 400. Among them, the structure of the active unloading valve 400 is basically the same as that in embodiment one, only the different structures are described here.

[0033] See Figure 11 and Figure 12 , the two-position three-way electromagnetic valve includes a valve body two 501, the valve body two 501 is inserted and fixed in the valve body one 401, and the head of the valve body two 501 is sealingly inserted into the back cavity 403 of the valve core one, and the two ends of the spring one 405 are respectively abutted between the valve core one 402 and the valve body two 501.

[0034] The tail end inner periphery of the valve body one 401 is provided with a threaded segment one, the valve body two 501 is inserted into the tail end interior of the valve body one 401, and the valve body two 501 is connected with the threaded segment one. Further, see Figure 11 , the tail end of the valve body one is provided with a tail seat one, the tail end outer periphery of the valve body one is connected with the tail seat one through threads, the threaded segment one is arranged at the tail end inner periphery of the tail seat one, the outer periphery of the tail seat one is further provided with a threaded segment two connected to the valve seat of the multi-way valve, the head of the valve body two is sealingly inserted into the tail end interior of the valve body one 401, the middle part of the valve body two is sealingly inserted into the tail seat one, and the tail end of the valve body two is connected to the threaded segment one through a tail seat two, the tail seat two and the tail end of the valve body two are connected through threads, which constitutes an integrated threaded plug-in structure.

[0035] The two-position three-way electromagnetic valve is provided with an oil inlet P2, a working port A2 and an oil return port T2, the valve body two 501 is provided with an oil port B503 in communication with the oil return port T2 and an oil port C505 in communication with the oil inlet P2, the valve core two 504 is slidably arranged in the valve body two 501, the valve core two 504 is provided with an oil port A502 in communication with the working port A2, the valve core two 504 is slidably arranged to alternatively open and close the oil passage between the oil port A502 and the oil port B503 and the oil passage between the oil port A502 and the oil port C505, and the working port A2 is arranged in the valve body two 501 and in communication with the back cavity 403.

[0036] The valve core two 504 is further provided with an oil channel one 506 in communication with the oil port A502 and the oil port B503, the valve body one 401 is provided with an oil channel two 507 in communication with the oil port B503 and the oil return port T2, and the valve body one 401 is provided with an oil channel three 508 in communication with the oil port C505 and the working port P2.

[0037] The working principle of the embodiment is as follows: When the two-position three-way electromagnetic valve is not powered, referring to Figure 2 The two-position three-way electromagnetic valve is in the left position, at this time, the oil passage between the oil port A502 and the oil port B503 is connected, the oil passage between the oil port A502 and the oil port C505 is disconnected, when the oil inlet P3 is filled with oil, part of the hydraulic oil of the oil inlet P3 flows to the back cavity 403 through the throttle port 404, and then flows into the oil return tank through the oil port A502, the oil port B503 and the oil return port T2 in sequence to be unloaded, and the pressure in the back cavity 403 cannot be established, when the pressure at the oil inlet is large, the spring one 405 is pushed upward to open the valve core one 402 (when there is no spring one 405, the elastic force of the spring one 405 does not need to be overcome), the oil passage between the oil inlet P3 and the oil return port T3 is connected, the hydraulic oil flows to the oil return port T3 through the oil inlet P3 to be unloaded, at this time, the active unloading valve 400 is in a nearly zero-pressure conduction state, and the hydraulic system is nearly zero-pressure unloaded. When the two-position three-way electromagnetic valve is powered, referring to Figure 2When the two three-way electromagnetic valves are in the right position, the oil passage from the oil port A 502 to the oil port B 503 is disconnected, the oil passage between the oil port A 502 and the oil port C 505 is connected, and after the oil inlet P3 is filled with oil, the active unloading valve is in the unloading state, part of the hydraulic oil in the oil inlet P3 flows to the back cavity 403 through the throttle hole 404 of the valve core 1 402, and because the oil passage between the oil port A 502 and the oil port B 503 is disconnected and the oil passage between the oil port A 502 and the oil port C 505 is connected, the pressure oil in the back cavity 403 cannot be unloaded through the oil return port T3 at this time, and the pressure oil after pressure reduction enters the working port A2 through the oil port C 505 and the oil port A 502, and the hydraulic oil accumulates to establish pressure in the back cavity 403, and under the spring force of the spring 1 405 and the pressure difference (caused by the area difference), the back cavity 403 can push the valve core 1 402 downward, so that the valve core 1 402 moves in the closing direction, and when the unloading force is equal to the force in the back cavity 403, the two sides are balanced, and the valve core stops moving, and at this time, the pilot pressure of the entire hydraulic system is established.

[0038] Example five: the structure of this embodiment is basically the same as that of example four, and the difference mainly lies in the position of the throttle hole 404 of the active unloading valve 400. In example four, the liquid resistance valve internal connection structure is that a small-diameter throttle hole 404 is processed inside the valve core 1 402 of the active unloading valve 400. In example five, the liquid resistance valve external connection structure refers to that the throttle hole 404 is arranged on the valve seat outside the valve body 1 401 to connect the oil inlet P3 and the back cavity outside the active unloading valve 400, and the throttle hole 404 can be directly cast or processed with a small-diameter oil passage on the valve seat, and at this time, the working principle is basically the same as that of example four. Figure 13

[0039] Example six: the structure of this embodiment is basically the same as that of example one, and the difference mainly lies in the different pressure reducing valve 300. In example one, a kind of overflow pressure reducing valve, namely a bidirectional pressure reducing valve 300, is adopted, and the principle is that a valve body and a pilot oil passage (which can be simply understood as a direct-acting overflow valve) are composed, when the oil inlet pressure is less than the set pressure, the pilot oil passage is not connected, and no overflow is generated. When the oil inlet pressure is greater than the set pressure, the pilot oil passage is opened, so that a pressure difference is formed in the valve body, and under the action of the pressure difference, the valve core is opened, and overflow is generated. The overflow pressure reducing valve not only has the function of reducing high-pressure oil to the low-pressure oil required by the pilot pressure oil, but also has the function of the overflow valve. In example six, a conventional pressure reducing valve 300 in the prior art is adopted, and the principle diagram is shown in Figure 14 ​The principle is: the oil inlet pressure is reduced to the required outlet pressure (usually low pressure), and the low pressure outlet pressure is kept stable, at this time the working principle is basically the same as that of example one.

[0040] Example seven: the structure of this example is basically the same as that of other examples, the main difference is that the throttle port 404 of the active unloading valve 400 is an overflow valve and the pressure reducing valve 300 is a conventional pressure reducing valve 300, the principle diagram is shown in Figure 15 , at this time the working principle is basically the same as that of example one.

[0041] Example eight: the structure of this example is basically the same as that of other examples, the main difference is that an overflow valve 600 is arranged between the pressure reducing valve 300 and the two-position three-way electromagnetic valve, the conventional pressure reducing valve 300 is used in cooperation with the overflow valve 600, so that the system not only has the function of reducing pressure, but also has the function of overflow, the principle diagram is shown in Figure 16 , at this time the working principle is basically the same as that of example one.

[0042] Example nine: the difference between this example and example one is that the oil inlet port P3 of the active unloading valve 400 is connected to the end of the pressure oil circuit of the multi-way valve, as shown in Figure 17 and Figure 18 . This example uses the end of the pressure oil circuit to replace the middle unloading oil circuit end of example one, and arranges the unloading valve group at the end of the pressure oil circuit, which solves the same technical problem, and the working principle at this time is the same as that of example one, which will not be described here.

[0043] Example ten: the structure of this example is basically the same as that of example nine, the main difference is that the throttle port in this example is arranged outside the active unloading valve, as shown in Figure 19 .

[0044] Example eleven: the structure of this example is basically the same as that of example nine, the main difference is that, as shown in Figure 20 , the end of the middle unloading oil circuit is connected to the return oil circuit of the active unloading valve, and a throttle port is arranged on the oil circuit, so that the middle oil circuit can be unloaded at a smaller pressure.

[0045] When the electromagnetic valve 500 is not powered, the active unloading valve is in a nearly zero pressure conduction state, and the hydraulic system is unloaded at a nearly zero pressure; when there is a signal input, the electromagnetic valve 500 is powered, the active unloading valve is gradually closed, and at the same time the middle unloading oil circuit is unloaded through the throttle port, so that the whole system establishes pressure and runs at low pressure, which meets the ability state that can recover operation. The working principle is basically the same as that of example six.

[0046] Embodiment twelve: the structure of the electromagnetic valve 500 in this embodiment is different from that in embodiment one. In this embodiment, the electromagnetic valve 500 is a two-position four-way electromagnetic valve 500. See Figures 21 to 23 .

[0047] The two-position four-way electromagnetic valve 500 includes an oil inlet P2, a working port A2, an oil return port T2, and an oil return port T4 connected to an oil return tank. The two-position four-way electromagnetic valve 500 includes a valve body two 501, which is further provided with an oil port A502 in communication with the working port A2, an oil port B503 in communication with the oil return port T2, an oil port C505 in communication with the oil inlet P2, and an oil port D509 in communication with the oil return port T4. A spool two 504 is slidably arranged in the valve body two. The spool two alternately slides to open and close the oil path between the oil port A502 and the oil port B503, the oil path between the oil port A502 and the oil port C505, and the oil path between the oil port C505 and the oil port D509. When the two-position four-way electromagnetic valve 500 is not powered, the working port A2 is in communication with the oil return port T2, the working port A2 is disconnected from the oil inlet P2, and the oil inlet P2 is in communication with the oil return port T4. When the two-position four-way electromagnetic valve 500 is powered, the working port A2 is in communication with the oil inlet P2, the working port A2 is disconnected from the oil return port T2, and the oil inlet P2 is disconnected from the oil return port T4.

[0048] The working principle of this embodiment is basically the same as that of embodiment one, and will not be repeated here. The difference is that when the two-position four-way electromagnetic valve 500 is not powered, the working port A2 is in communication with the oil return port T2, the working port A2 is disconnected from the oil inlet P2, and the oil inlet P2 is in communication with the oil return port T4. When the two-position four-way electromagnetic valve 500 is powered, the working port A2 is in communication with the oil inlet P2, the working port A2 is disconnected from the oil return port T2, and the oil inlet P2 is disconnected from the oil return port T4.

[0049] Embodiment thirteen: this embodiment is to replace the two-position three-way electromagnetic valve in embodiment six with a two-position four-way electromagnetic valve 500. The oil inlet P3 of the active unloading valve 400 is connected to the end of the pressure oil path of the multi-way valve. See Figure 24 .

[0050] Embodiment fourteen: this embodiment is to replace the two-position three-way electromagnetic valve in embodiment seven with a two-position four-way electromagnetic valve 500. The throttle in this embodiment is arranged outside the active unloading valve. See Figure 25 .

[0051] Embodiment fifteen: this embodiment is to replace the two-position three-way electromagnetic valve in embodiment eight with a two-position four-way electromagnetic valve 500. The end of the mid-position unloading oil path is connected to the oil return path of the active unloading valve, and a throttle is arranged on the oil path. See Figure 26 .

[0052] Example Sixteen: This example is similar to Example Five, except that this example uses a two-position, four-way solenoid valve 500, as shown in Fig. 5. Figure 27 .

[0053] Example Seventeen: This example is similar to Example Six, except that this example uses a two-position, four-way solenoid valve 500, as shown in Fig. 5. Figure 28 .

[0054] Example Eighteen: This example is similar to Example Seven, except that this example uses a two-position, four-way solenoid valve 500, as shown in Fig. 5. Figure 29 .

[0055] Example Nineteen: This example is similar to Example Eight, except that this example uses a two-position, four-way solenoid valve 500, as shown in Fig. 5. Figure 30 .

[0056] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims.

Claims

1. A random reconstruction system for the secondary pilot pressure of an open-type multi-way valve unloading oil circuit, characterized in that: It includes a multi-way valve installed on the main oil line and an unloading valve group located at the end of the unloading oil line of the multi-way valve. The multi-way valve includes several directional valves, a proportional valve that controls the operation of the directional valves, and a pressure reducing valve located between the main oil line and the proportional valve. The unloading valve assembly includes an active unloading valve, a solenoid valve, and a pressure reducing valve in a multi-way valve. The active unloading valve includes an inlet P3, a working port A3, and a return port T3. The inlet P3 is connected to the end of the unloading oil circuit of the multi-way valve, and the return port T3 is connected to the return oil tank. The active unloading valve has a back cavity, and the working port A3 communicates with the back cavity. The inlet P3 is also connected to the back cavity through a throttling port. The solenoid valve includes an inlet P2, a working port A2, and a return port T2. The return port T2 is connected to the return oil tank, and the working port A2 communicates with the working port A3. The pressure reducing valve includes a working port A1 and an inlet P1. The working port A1 communicates with the inlet P2, and the inlet P1 is connected to the system pressure oil circuit. When the solenoid valve is not energized, the oil circuit between the working port A2 and the return port T2 is connected, and the back cavity is connected to the return oil tank through the working port A3, the working port A2, and the return port T2. The back cavity can be unloaded through the solenoid valve. At this time, the active unloading valve is fully opened, and the oil circuit between the inlet port P3 and the return port T3 is fully connected for zero-pressure unloading. When the solenoid valve is energized, the oil circuit between the working port A2 and the oil inlet P2 is connected. The constant pressure oil after being depressurized by the pressure reducing valve establishes back pressure in the back cavity. The active unloading valve gradually closes partially, and the oil circuit between the oil inlet P3 and the oil return port T3 is partially connected to perform low-pressure unloading.

2. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 1, characterized in that: The unloading valve assembly is connected to the end of the unloading oil circuit or the end of the pressure oil circuit of the multi-way valve.

3. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 1, characterized in that: The active unloading valve includes a valve body, an oil inlet P3 located at the head end of the valve body, an oil return port T3 located at the side of the valve body, a valve core slidably disposed inside the valve body, the valve core slidably sliding along the valve body to connect or disconnect the oil passage between the oil inlet P3 and the oil return port T3, and a back cavity located at the tail end of the valve core.

4. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 3, characterized in that: The solenoid valve is a two-position three-way solenoid valve or a two-position four-way solenoid valve.

5. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 4, characterized in that: The active unloading valve and the two-position three-way solenoid valve are separately configured. The two-position three-way solenoid valve includes an oil inlet P2, a working port A2, and an oil return port T2. The two-position three-way solenoid valve also includes a valve body two. The valve body two is also provided with an oil port A connected to the working port A2, an oil port B connected to the oil return port T2, and an oil port C connected to the oil inlet P2. A valve core two is slidably provided inside the valve body two. The valve core two slidably alternately opens and closes the oil passage between oil port A and oil port B, and the oil passage between oil port A and oil port C. Alternatively, the active unloading valve and the two-position three-way solenoid valve may be integrated into one unit. The two-position three-way solenoid valve includes a valve body two. The valve body two is inserted and fixed inside the valve body one, and the head of the valve body two is sealed and inserted into the back cavity inside the valve core one. The valve body two is provided with an oil port B communicating with the oil return port T2 and an oil port C communicating with the oil inlet port P2. A valve core two is slidably provided inside the valve body two. The valve core two is provided with an oil port A communicating with the working port A2. The valve core two slides alternately to open and close the oil passage between oil port A and oil port B, and the oil passage between oil port A and oil port C. The working port A2 is located inside the valve body two and communicates with the back cavity.

6. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 4, characterized in that: The two-position four-way solenoid valve includes an inlet port P2, a working port A2, a return port T2, and a return port T4. The return port T4 is connected to the return oil tank. The two-position four-way solenoid valve includes a valve body two. The valve body two is also provided with an oil port A connected to the working port A2, an oil port B connected to the return port T2, an oil port C connected to the inlet port P2, and an oil port D connected to the return port T4. A valve core two is slidably provided inside the valve body two. The valve core two slidably alternately opens and closes the oil passage between oil port A and oil port B, the oil passage between oil port A and oil port C, and the oil passage between oil port C and oil port D.

7. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 3, characterized in that: The throttling port is located on the valve core and connects the oil inlet P3 with the back cavity inside the active unloading valve.

8. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 3, characterized in that: The throttling port is located on the valve seat outside the valve body, connecting the oil inlet P3 to the back cavity outside the active unloading valve.

9. The open-core multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 1, characterized in that: The pressure reducing valve is an overflow pressure reducing valve, which includes a valve body three. The working port A1 is located at one end of the valve body three. The oil inlet P1 and the oil return port T1 are located on the side of the valve body three, with the oil inlet P1 close to the working port A1. A valve core three is slidably provided inside the valve body three. The head end of the valve core three corresponds to the working port A1. The valve core three can slide along the inside of the valve body three to switch between the oil circuit between the oil inlet P1 and the working port A1 or the oil circuit between the oil inlet P1 and the oil return port T1.

10. The open-heart multi-way valve unloading oil circuit secondary pilot pressure random reconstruction system as described in claim 1, characterized in that: An overflow valve is also provided between the pressure reducing valve and the solenoid valve.

Images