WO2023035583A1 - 液压控制系统及作业机械 - Google Patents

液压控制系统及作业机械 Download PDF

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Publication number
WO2023035583A1
WO2023035583A1 PCT/CN2022/081262 CN2022081262W WO2023035583A1 WO 2023035583 A1 WO2023035583 A1 WO 2023035583A1 CN 2022081262 W CN2022081262 W CN 2022081262W WO 2023035583 A1 WO2023035583 A1 WO 2023035583A1
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WO
WIPO (PCT)
Prior art keywords
valve
communicates
oil
control
reversing
Prior art date
Application number
PCT/CN2022/081262
Other languages
English (en)
French (fr)
Inventor
刘玉湘
何勤求
赵汗青
Original Assignee
湖南三一华源机械有限公司
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Application filed by 湖南三一华源机械有限公司 filed Critical 湖南三一华源机械有限公司
Publication of WO2023035583A1 publication Critical patent/WO2023035583A1/zh

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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/76—Graders, bulldozers, or the like with scraper plates or ploughshare-like elements; Levelling scarifying devices
    • E02F3/80—Component parts
    • E02F3/84—Drives or control devices therefor, e.g. hydraulic drive systems
    • E02F3/841—Devices for controlling and guiding the whole machine, e.g. by feeler elements and reference lines placed exteriorly of the machine
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/02—Installations or systems with accumulators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/08—Servomotor systems without provision for follow-up action; Circuits therefor with only one servomotor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/16—Servomotor systems without provision for follow-up action; Circuits therefor with two or more servomotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure

Definitions

  • the application belongs to the technical field of hydraulic control, and relates to a hydraulic control system and a working machine.
  • the working state of the lifting cylinder is controlled through two sets of hydraulic oil circuits, one of which controls the lifting cylinder to normally drive the lifting of the blade, and the other set of hydraulic oil circuits uses additional pressure oil
  • the source controls the oil pressure of the rod chamber of the lifting cylinder to offset part of the self-weight of the blade.
  • the application provides a hydraulic control system and a working machine, which are used to solve or improve the technical problem that related control schemes cannot realize the adjustment of the working mode and floating mode of the lifting cylinder and affect the working efficiency of the motor grader.
  • the application provides a hydraulic control system, including: a hydraulic pump, an oil tank, a lift control valve, a lift cylinder, and a floating control valve group; the lift control valve is used to control the optional rod chamber and rodless chamber of the lift cylinder The telescopic end of the lifting cylinder is used to connect with the working mechanism; the floating control valve group includes a pressure reducing valve and a control valve; the hydraulic pump passes through the pressure reducing valve in turn.
  • the pressure valve and the control valve communicate with the lift cylinder; when the control valve is in the first state, the rod chamber of the lift cylinder communicates with the pressure reducing valve, and the rodless cavity of the lift cylinder The chamber communicates with the oil tank, and when the control valve is in the second state, the oil circuit where the floating control valve group is located is cut off.
  • the rodless chamber of the lifting cylinder communicates with the pressure reducing valve
  • the rod chamber of the lifting cylinder communicates with the pressure reducing valve
  • the floating control valve group is used to control the rod chamber and the rodless chamber of the lifting cylinder to communicate with the oil tank respectively.
  • the control valve includes a first reversing valve, a first on-off valve and a second on-off valve; the oil inlet of the first reversing valve communicates with the decompression valve , one of the working oil ports of the first reversing valve communicates with the rod chamber of the lifting cylinder through the first switch valve, and the other working oil port of the first reversing valve communicates with the rod chamber of the lifting cylinder through the second
  • the on-off valve communicates with the rodless cavity of the lift cylinder, and the oil return port of the first reversing valve communicates with the oil tank.
  • the first reversing valve is an electromagnetic reversing valve
  • the pressure reducing valve is a proportional electromagnetic pressure reducing valve
  • At least one of them is an electromagnetic switch valve
  • the pressure reducing valve has a first port, a second port and a third port; the second port can be selectively communicated with the first port or the third port;
  • the first port communicates with the hydraulic pump, the second port communicates with the oil inlet of the first reversing valve, and the third port communicates with the oil tank.
  • the first reversing valve includes a neutral conduction state, a first reversing state and a second reversing state; when the first reversing valve is in the neutral position
  • the oil inlet port of the first reversing valve communicates with the two working oil ports of the first reversing valve respectively, and the rod chamber of the lifting oil cylinder is connected with the rodless chamber of the lifting oil cylinder.
  • the first reversing valve when the first reversing valve is in the first reversing state, the first on-off valve communicates with the second on-off valve, and the second port of the decompression valve communicates with the The first port of the pressure reducing valve is connected, and the oil tank is connected with the rod cavity of the lifting cylinder through the pressure reducing valve, the first reversing valve and the first switching valve in sequence, and the lifting cylinder
  • the rodless cavity communicates with the oil tank; when the first reversing valve is in the second reversing state, the first on-off valve communicates with the second on-off valve, and the second port of the decompression valve communicates with the The first port is connected, the oil tank is connected with the rodless chamber of the lifting cylinder through the pressure reducing valve, the first reversing valve and the second switching valve in turn, and the rod chamber of the lifting cylinder is communicate with the fuel tank.
  • a hydraulic control system provided according to the present application further includes: an accumulator; the accumulator can be selectively communicated with the rodless cavity of the lifting cylinder.
  • a hydraulic control system provided by the present application, it further includes: a first pressure sensor and a third switch valve; the first pressure sensor is used to detect the oil pressure of the accumulator; the accumulator passes through the The third on-off valve communicates with the rodless cavity of the lift cylinder; the first pressure sensor communicates with the third on-off valve so that the third on-off valve can be controlled according to the oil pressure of the accumulator The state of communication between the accumulator and the lift cylinder.
  • the third switch valve is an electromagnetic switch valve.
  • the lifting control valve has a first conduction state, a second conduction state, a third conduction state and a fourth conduction state; when the lift control valve is in the first In the conduction state, the rod chamber and the rodless chamber of the lifting cylinder are respectively cut off from the hydraulic pump and the oil tank, and the control valves corresponding to the floating control valve group are in the first state, the third state and Any one of the fourth state; when the lift control valve is in the second conduction state or the third conduction state, one of the rod chamber and the rodless chamber of the lift cylinder is in the same state as the The hydraulic pump is connected, and the other of the rod chamber and the rodless chamber is connected with the oil tank, and the control valve corresponding to the floating control valve group is in the second state; when the lift control valve is in the first state In the case of the four-conduction state, the rod chamber and the rodless chamber of the lifting cylinder communicate with the oil tank respectively, and the control valve corresponding to the floating control valve group is
  • the lifting control valve includes a second reversing valve and a differential pressure valve; selectively communicate with the hydraulic pump or the oil tank; a first valve lock is provided on the oil path between one of the working oil ports of the second reversing valve and the rodless chamber of the lift cylinder, and the A second valve lock is provided on the oil path between the other working oil port of the second reversing valve and the rod cavity of the lift cylinder; one end of the differential pressure valve is connected to the hydraulic pressure in the second reversing valve.
  • the lock opening oil circuit is connected, and the other end is respectively connected with the first valve lock and the second valve lock; the differential pressure valve is used to synchronously control the first valve according to the oil pressure on the second reversing valve The conduction state of the lock and the second valve lock.
  • a hydraulic control system provided by the present application, it also includes: a control module and a second pressure sensor; the second pressure sensor is used to detect the oil pressure of the hydraulic lock opening oil circuit in the lift control valve, and the second The pressure sensor is in communication connection with the control module; the control module is in communication connection with the floating control valve group.
  • the hydraulic pump is a variable displacement pump
  • the floating control valve group communicates with the first end of the shuttle valve, the second end of the shuttle valve communicates with the lifting control valve, and the The third end communicates with the feedback oil port of the variable displacement pump;
  • the two sets of the hydraulic control systems are respectively used to drive and control the working mechanisms arranged on the left and right sides of the working machine; the two sets of the hydraulic control systems share one of the Variable displacement pump; the shuttle valve includes a first shuttle valve, a second shuttle valve and a third shuttle valve; two sets of floating control valve groups of the hydraulic control system are respectively connected to the first end and the second The lift control valve of one of the two sets of hydraulic control systems communicates with the first end of the second shuttle valve, and the lift control valve of the other of the two sets of hydraulic control systems communicates with the first end of the third shuttle valve.
  • the second end of the shuttle valve communicates; the third end of the first shuttle valve communicates with the second end of the second shuttle valve; the third end of the second shuttle valve communicates with the first end of the third shuttle valve One end is connected, and the third end of the third shuttle valve is connected with the feedback oil port of the variable displacement pump.
  • the present application also provides a working machine, including the above-mentioned hydraulic control system.
  • the working machine is a grader, and the working mechanism of the grader is a blade.
  • the application provides a hydraulic control system and working machinery.
  • the hydraulic control system includes a hydraulic pump, an oil tank, a lifting control valve, a floating control valve group, and a lifting oil cylinder.
  • the power provided by the same hydraulic pump passes through the lifting control valve and the floating control valve respectively.
  • the valve group controls the working conditions of the lifting cylinder; not only can the lifting control valve control the lifting cylinder to perform normal lifting movement to meet the operating needs of the operating mechanism under normal working conditions, but also control the lifting cylinder through the floating control valve group It is in a light-load floating state, which can reduce the labor intensity of the operator and improve the operation efficiency and effect.
  • the hydraulic control system shown in this application has a simple structure and low cost, and can independently control the lifting cylinder to work in the working mode and the light-load floating mode, so as to ensure the reliability of the operation of the working machine.
  • Fig. 1 is the structural representation of the hydraulic control system that the application provides;
  • Fig. 2 is a schematic structural diagram of the control module provided by the present application being connected to each sensing component and executing component;
  • Fig. 3 is a schematic structural view of the lift control valve provided by the present application.
  • Fig. 4 is the structural representation that two sets of hydraulic control systems provided by the application are connected;
  • Fig. 5 is a schematic flow chart of the initial accumulator pressure adjustment of the accumulator provided by the present application
  • Fig. 6 is a schematic flow chart of the self-weight floating mode of the control operation mechanism provided by the present application.
  • Fig. 7 is a schematic flow chart of the control operation mechanism provided by the present application in the light-load floating mode
  • Fig. 8 is a schematic flow diagram of the control operation mechanism provided by the present application in the heavy-load floating mode
  • control module control module
  • 13 shuttle valve
  • 131 first shuttle valve
  • this embodiment provides a hydraulic control system, including: a hydraulic pump 2, a fuel tank 1, a lift control valve 4 and a lift cylinder 6; the hydraulic pump 2 and the fuel tank 1 communicate with the lift cylinder 6 through the lift control valve 4 , the telescoping end of lifting cylinder 6 is used for being connected with operating mechanism.
  • the lift control valve 4 is used to control the rod cavity and the rodless cavity of the lift cylinder 6 to selectively communicate with the hydraulic pump 2 or the oil tank 1 .
  • the lift control valve 4 controls the rod cavity of the lift cylinder 6 to communicate with the hydraulic pump 2, the rodless cavity of the lift cylinder 6 communicates with the oil tank 1, so that the lift cylinder 6 can control the working mechanism to rise;
  • the lift control valve 4 When the rodless chamber of the control lifting cylinder 6 is connected with the hydraulic pump 2, the rod chamber of the lifting cylinder 6 is connected with the oil tank 1, and the lifting cylinder 6 is used to control the lowering of the working mechanism; the lifting control valve 4 can also control the rod chamber of the lifting cylinder 6 and the rodless cavity are cut off with the hydraulic pump 2 and the oil tank 1 respectively.
  • the hydraulic control system is also provided with a floating control valve group 5; the floating control valve group 5 includes a pressure reducing valve 52 and a control valve; the hydraulic pump 2 communicates with the lifting cylinder 6 through the pressure reducing valve 52 and the control valve in sequence.
  • the control valve is used to control the rod chamber and the rodless chamber of the lifting cylinder 6 to be selectively communicated with the pressure reducing valve 52 or the oil tank 1; when the control valve is in the first state, the rod chamber and the pressure reducing chamber of the lifting cylinder 6 The pressure valve 52 is connected, and the rodless cavity of the lifting cylinder 6 is connected with the oil tank 1.
  • the control valve is in the second state, the oil circuit where the floating control valve group 5 is located is cut off.
  • the lifting control valve 4 and floating control valve group 5 can be used to pair the lifting cylinders respectively. 6 to control the operating conditions; because when the control valve is in the second state, the oil circuit where the floating control valve group is located is cut off, the hydraulic control system can control the lifting cylinder 6 to perform lifting movement through the lifting control valve 4, so as to meet the operating mechanism. Under normal working conditions, when the lifting control valve 4 is in the cut-off state, the hydraulic control system can fill the rod chamber of the lifting cylinder 6 with hydraulic oil through the floating control valve group 5 to offset part of the self-weight of the working mechanism. Therefore, the lifting cylinder 6 is controlled to be in the light-load floating state, so that the system has lower energy consumption when operating in the light-load floating mode, and the operating efficiency and effect are improved.
  • the hydraulic control system shown in this embodiment has a simple structure and low cost. It can independently control the lifting cylinder to work in the working mode and the light-load floating mode without additional pressure oil source. It is not only simple in structure and low in cost, but also easy to arrange.
  • the control valve shown in this embodiment can be understood as an on-off valve or a combination valve composed of an on-off valve and other types of valves, which is used to control the conduction or connection of the oil circuit between the decompression valve 52 and the rod cavity of the lifting cylinder 6. due.
  • control valve shown in this embodiment also has a third state and a fourth state.
  • the control valve is in the third state, since the rodless cavity of the lifting cylinder 6 communicates with the pressure reducing valve 52, and the rod cavity of the lifting cylinder 6 communicates with the oil tank 1, the hydraulic oil output by the hydraulic pump 2 passes through the pressure reducing valve 52. After the decompression treatment, it is sent to the rodless chamber of the lifting cylinder 6, and the rod chamber of the lifting cylinder 6 returns oil to the oil tank 1, so that the oil pressure in the rodless chamber of the lifting cylinder 6 increases to control the operating mechanism to work under heavy load. floating mode.
  • the lifting control valve 4 When the lifting control valve 4 is in the cut-off state, by switching the control valve to the fourth state, the rod cavity and the rodless cavity of the lifting cylinder 6 can be communicated with the oil tank 1 respectively, so that the working mechanism can be controlled by the lifting cylinder 6 to work in Self-weight floating mode.
  • the hydraulic control system shown in this embodiment is also provided with a filter 3; the hydraulic pump 2 communicates with the lift control valve 4 through the filter 3.
  • the filter 3 is used to filter the oil in the hydraulic system to ensure the cleanliness of the oil entering the hydraulic system.
  • the filter 3 includes a filter unit and a bypass valve, the bypass valve is connected in parallel with the filter unit, and the bypass valve is used to open when the filter element of the filter unit is blocked to prevent damage to the filter element.
  • the control valve includes a first reversing valve 51, a first switching valve 53 and a second switching valve 54; the oil inlet of the first reversing valve 51 communicates with the pressure reducing valve, and the first reversing valve 51 One of the working oil ports of the first reversing valve 51 communicates with the rod chamber of the lifting cylinder 6 through the first switch valve 53, and the other working oil port of the first reversing valve 51 communicates with the rodless chamber of the lifting cylinder 6 through the second switching valve 54.
  • the oil return port of the first reversing valve 51 communicates with the oil tank 1 .
  • the first reversing valve 51 is a three-position, four-way electromagnetic reversing valve.
  • the pressure reducing valve 52 is a proportional pressure reducing valve, and the proportional pressure reducing valve is preferably a proportional electromagnetic pressure reducing valve.
  • At least one of the first on-off valve 53 and the second on-off valve 54 is an electromagnetic on-off valve.
  • the decompression valve has a first port, a second port and a third port; the second port can be selectively communicated with the first port or the third port; the first port is communicated with the hydraulic pump, and the second port is communicated with the second port
  • the oil inlet port of a reversing valve 51 is connected, and the third port is connected with the oil tank 1 .
  • the first reversing valve 51 has a neutral conduction state, a first reversing state and a second reversing state.
  • the oil inlet port of the first reversing valve 51 is connected with the two working oil ports of the first reversing valve 51 respectively, and the first switching valve 53 and the The second switching valve 54 conducts, and the second port of the control pressure reducing valve 52 communicates with the third port, so that the rod chamber and the rodless chamber of the lifting cylinder 6 can be connected with the oil tank 1 respectively, so that the lifting cylinder 6 can be in the position of Floating state to realize the self-weight floating work of the operating mechanism.
  • the pump 2 can pump the hydraulic oil in the oil tank 1 to the rod cavity of the lifting cylinder 6 through the pressure reducing valve 52, the first reversing valve 51 and the first switch valve 53 in sequence, and the rodless cavity of the lifting cylinder 6 is pumped to the oil tank. 1 returns the oil, so that the oil pressure in the rod chamber of the lifting cylinder 6 is strengthened, to offset the part of the dead weight of the operating mechanism, and realize the light-load floating work of the operating mechanism.
  • the pump 2 can pump the hydraulic oil in the oil tank 1 to the rodless chamber of the lifting cylinder 6 through the pressure reducing valve 52, the first reversing valve 51 and the second switching valve 54 in sequence, and the rod chamber of the lifting cylinder 6 is pumped to the oil tank 1.
  • the oil return makes the oil pressure of the rodless chamber of the lifting cylinder 6 strengthen, so as to increase the ground pressing force of the operating mechanism and realize the heavy-duty floating work of the operating mechanism.
  • the hydraulic control system is also provided with an accumulator 7; the accumulator 7 can be selectively communicated with the rodless cavity of the lifting cylinder 6.
  • the working mechanism is in the normal working mode. When leveling the hard road surface, the working mechanism will be greatly impacted.
  • the accumulator 7 By connecting the accumulator 7 with the rodless chamber of the lifting cylinder 6, the accumulator 7 can be used to absorb
  • the hydraulic oil in the rodless cavity of the lifting cylinder 6 is used to reduce the impact load of the operating mechanism, realize buffering, floating and obstacle avoidance, and improve the service life of the operating mechanism.
  • the hydraulic control system is also provided with a first pressure sensor 11 and a third switching valve 8; the first pressure sensor 11 is used to detect the oil pressure of the accumulator 7; The rodless cavity of 6 is communicated; the first pressure sensor 11 is connected with the third switch valve 8 in communication, so that the third switch valve 8 can control the communication state of the accumulator 7 and the lifting cylinder 6 according to the oil pressure of the accumulator 7 .
  • the first pressure sensor 11 is communicatively connected with the control module 100
  • the control module 100 is communicatively connected with the third switch valve 8 .
  • the third on-off valve 8 shown in this embodiment is preferably an electromagnetic on-off valve.
  • the control module 100 may be a well-known human-computer interaction module in the art.
  • the human-computer interaction module not only has a certain logic operation capability, but also can accept user parameter instruction input, and can also display data in real time.
  • the human-computer interaction module may be a touch screen controller or an intelligent display screen with logic judgment capability.
  • the hydraulic pump 2 shown in the present embodiment can sequentially pass through the floating control valve group 5 and the third switching valve 8 to
  • the accumulator 7 is filled with hydraulic oil.
  • the control module 100 controls the initial pressure of the accumulator 7 by controlling the opening and closing of the third on-off valve 8 according to the pressure signal fed back by the first pressure sensor 11, so as to realize different initial accumulator pressures for the accumulator 7 In order to adjust the response threshold to the impact load, reduce the impact load and work precision, and improve the adaptability of the work machine to different hardness road surfaces.
  • the operator can match the corresponding initial pressure to the accumulator 7 according to the specific construction road conditions.
  • the accumulator 7 can be controlled to maintain a relatively large initial pressure, increase the response threshold of the operating mechanism to the impact load, ensure that the operating mechanism has greater ground pressure, reduce the impact and improve the level of operation degree; for roads with large impact, the accumulator 7 can be controlled to maintain a relatively small initial pressure, reduce the response threshold of the operating mechanism to the impact load, and ensure that the operating mechanism has a smaller ground pressing force to reduce the pressure to a greater extent. shock.
  • the lifting control valve 4 shown in this embodiment has a first conduction state, a second conduction state, a third conduction state and a fourth conduction state.
  • the lift control valve 4 When the lift control valve 4 is in the first conduction state, the rod cavity and the rodless cavity of the lift cylinder 6 are cut off from the hydraulic pump 2 and the oil tank 1 respectively. Since neither the rod chamber nor the rod chamber of the lifting cylinder 6 can be fed with hydraulic oil through the lifting control valve 4, the lifting control valve 4 is in the cut-off state. At this time, the control valve corresponding to the controllable floating control valve group 5 is in the first state. , any one of the third state and the fourth state, so that the lifting cylinder 6 operates in the floating mode.
  • the lifting cylinder 6 When the control valve is in the first state, the lifting cylinder 6 can be controlled to be in the light-load floating mode; when the control valve is in the third state, the lifting cylinder 6 can be controlled to be in the heavy-load floating mode; when the control valve is in the fourth state, it can be Control the lifting oil cylinder 6 to be the self-weight floating mode.
  • the lifting control valve 4 When the lifting control valve 4 is in the second conduction state or the third conduction state, one of the rod chamber and the rodless chamber of the lifting cylinder 6 communicates with the hydraulic pump 2, and the rod chamber and the rodless chamber communicate with each other. The other one communicates with the oil tank 1. At this time, the lifting control valve 4 can control the telescopic end of the lifting cylinder 6 to perform a normal lifting action, and the lifting control valve 4 controls the lifting cylinder 6 to be in the working mode. In order to prevent the working mode and the floating mode of the lifting cylinder 6 from interfering with each other and avoid oil circuit conflicts, this embodiment can control the control valve corresponding to the floating control valve group 5 to be in the second state, so that the oil circuit where the floating control valve group is located is cut off .
  • the lift control valve 4 When the lift control valve 4 is in the fourth conduction state, the rod chamber and the rodless chamber of the lift cylinder 6 communicate with the oil tank 1 respectively, and the control valve corresponding to the float control valve group 5 is in the second state. Since the lifting control valve 4 controls the rod cavity and the rodless cavity of the lifting cylinder 6 to communicate with the fuel tank 1 respectively, and the oil circuit where the floating control valve group is located is cut off, the lifting cylinder 6 can be controlled to be in the self-weight floating mode.
  • the lift control valve 4 includes a second reversing valve 41; the second reversing valve 41 includes a manual reversing valve; the valve stem of the second reversing valve 41 has a first station, a second station, a third station position and the fourth position.
  • the hydraulic lock in the second reversing valve 41 is opened and the oil circuit is closed, so that the rod of the lifting cylinder 6
  • the cavity and the rodless cavity are cut off with the hydraulic pump 2 and the oil tank 1 respectively.
  • the hydraulic lock inside the second reversing valve 41 is opened, so that the second reversing valve 41 can control the hydraulic pump 2 to communicate with the rodless cavity of the lifting cylinder 6 , and the oil tank 1 communicates with the rod cavity of the lifting cylinder 6.
  • the extension of the telescopic end of the lifting cylinder 6 can be controlled by the second reversing valve 41 to control the lowering of the working mechanism.
  • the hydraulic lock inside the second reversing valve 41 is opened, so that the second reversing valve 41 is used to control the rod chamber of the hydraulic pump 2 and the lifting cylinder 6 Communication, and the oil tank 1 communicates with the rodless cavity of the lifting cylinder 6.
  • the telescoping end of the lifting cylinder 6 can be controlled to retract through the second reversing valve 41 to control the working mechanism to rise.
  • the second reversing valve 41 When the second reversing valve 41 is in the fourth position, the hydraulic lock inside the second reversing valve 41 is opened, and the second reversing valve 41 can control the rod chamber and the rodless chamber of the lifting cylinder 6 to connect with the fuel tank respectively. 1 is connected, and the rod cavity and the rodless cavity of the lifting cylinder 6 are respectively cut off from the hydraulic pump 2.
  • the second reversing valve 41 can control the operating mechanism to work in the self-weight floating mode, so that the operating mechanism floats with the road surface under the action of self-weight, and realizes self-weight floating obstacle avoidance.
  • the second reversing valve 41 is a manual reversing valve
  • the manual switching of the above four stations can be realized, so as to realize the mechanical interlocking between the self-weight floating mode and the working mode of the system through the limit of the handle, and improve the fault tolerance of the system .
  • the lifting control valve 4 shown in this embodiment also includes a differential pressure valve 42; a first valve lock 9 is provided on the oil path between one of the working oil ports of the second reversing valve 41 and the rodless cavity of the lifting cylinder 6, A second valve lock 10 is arranged on the oil path between another working oil port of the second reversing valve 41 and the rod chamber of the lift cylinder 6; Open the oil circuit to communicate, and the other end communicates with the first valve lock 9 and the second valve lock 10 respectively; the differential pressure valve 42 is used to synchronously control the first valve lock 9 and the second valve lock according to the oil pressure on the second reversing valve 41 10 on-state.
  • the second reversing valve 41 has a first oil port, a second oil port, a third oil port, a fourth oil port, a fifth oil port, a sixth oil port and a seventh oil port .
  • the first oil port, the second oil port, the third oil port, the fourth oil port, the fifth oil port, the sixth oil port and the seventh oil port are numbered "A", "B", “C”, “D”, “E”, “F", "G” for identification.
  • the second reversing valve 41 shown in Figure 3 is a reversing valve with three switching stations, and the second reversing valve 41 can realize the first station, the second station and the third station shown in the above-mentioned embodiments. Mutual switching between stations.
  • the second reversing valve 41 can also be selected as a reversing valve with four switching stations including the fourth station shown in the above embodiments. In this way, when the second reversing valve 41 is in the fourth position, by controlling the rod chamber and the rodless chamber of the lifting cylinder 6 to communicate with the oil tank 1 respectively, the working mechanism can also be made to work in the self-weight floating mode, so that the motor grader Realize self-weight floating obstacle avoidance during operation.
  • Both the first oil port and the second oil port of the second reversing valve 41 shown in this embodiment are used as working oil ports, and the first oil port of the second reversing valve 41 passes through the connection between the second valve lock 10 and the lifting cylinder 6 .
  • the rod cavity is communicated; the second oil port of the second reversing valve 41 communicates with the rodless chamber of the lift cylinder 6 through the first valve lock 9; the third oil port of the second reversing valve 41 is used as an oil inlet, and is connected with the The hydraulic pump 2 is connected; the fourth oil port of the second reversing valve 41 is used as an oil return port and communicated with the oil tank 1; the fifth oil port and the sixth oil port of the second reversing valve 41 are in a normally connected state.
  • the seventh oil port of the second reversing valve 41 shown in this embodiment is respectively connected to one end and the pilot end of the differential pressure valve 42, and the other end of the differential pressure valve 42 is connected to the sixth oil port of the second reversing valve 41. connected.
  • the sixth oil port of the second reversing valve 41 can selectively communicate with any one of the first oil port and the second oil port of the second reversing valve 41, and the sixth oil port of the second reversing valve 41
  • the port is connected to the first oil port
  • the second oil port of the second reversing valve 41 is connected to the fourth oil port
  • the sixth oil port of the second reversing valve 41 communicates with the fourth oil port.
  • the differential pressure valve 42 is in the state of being in the position because hydraulic oil is not fed into the leading end of the second reversing valve 41.
  • the hydraulic control system shown in this embodiment is also provided with a control module 100 and a second pressure sensor 12; Oil pressure, the second pressure sensor 12 is in communication connection with the control module 100 , and the control module 100 is in communication connection with the floating control valve group 5 .
  • the detection end of the second pressure sensor 12 shown in this embodiment is set at the sixth oil port of the second reversing valve 41 .
  • the second pressure sensor 12 shown in this embodiment is used to detect the oil pressure of the hydraulic lock opening oil circuit inside the lift control valve 4 . Because when the second reversing valve 41 is in the first position, the hydraulic lock inside the second reversing valve 41 is closed, and the differential pressure valve 42 is in the cut-off state, so that the sixth oil port of the second reversing valve 41 does not establish oil.
  • the control module 100 can realize the pressure signal of the second reversing valve 41 according to the pressure signal fed back by the second pressure sensor 12 .
  • the conduction state of the reversing valve 41 can be identified, and the conduction state of the floating control valve group 5 can be interlocked and controlled according to the conduction state of the second reversing valve 41 .
  • the working state of the lifting control valve 4 can be determined, so that based on the actual working state of the lifting control valve 4, the floating control valve group 5 can be matched to the corresponding working state. state, to selectively control the lifting cylinder 6 to work in the working state, buffer floating state, light-load floating state or self-weight floating state, thereby reducing the labor intensity of the operator and improving the operating efficiency and effect of the operating machine.
  • This embodiment is based on the interlocking control of the lifting control valve 4 and the floating control valve group 5, which can realize the interlocking between the working mode and the floating mode of the lifting cylinder, avoiding the disorder of the hydraulic system and improving the fault tolerance of the system.
  • the system shown in this embodiment is also provided with a shuttle valve 13;
  • the hydraulic pump 2 shown in the example is preferably a variable displacement pump.
  • the first end of the shuttle valve 13 is connected to the floating control valve group 5, the second end of the shuttle valve 13 is connected to the lifting control valve 4, and the third end of the shuttle valve 13 is connected to the feedback oil port of the variable pump. connected.
  • the first end of the shuttle valve shown in this embodiment is specifically communicated with the oil inlet port of the first reversing valve 51
  • the second end of the shuttle valve is specifically communicated with the fifth oil port of the second reversing valve 41 .
  • multiple sets of hydraulic control systems can be provided in this embodiment, and multiple sets of hydraulic control systems are connected to the multiple operating mechanisms in a one-to-one correspondence.
  • the hydraulic control system shown in this embodiment has two sets, which are respectively used to drive and control the working mechanisms located on the left and right sides of the working machine; the two sets of hydraulic control systems share a variable pump.
  • the shuttle valve 13 shown in this embodiment specifically includes a first shuttle valve 131, a second shuttle valve 132 and a third shuttle valve 133;
  • the floating control valve group 5 of the hydraulic control system communicates with the first end and the second end of the first shuttle valve 131 respectively, and the lift control valve 4 of one of the two hydraulic control systems communicates with the first end of the second shuttle valve 132.
  • the lifting control valve 4 of the other of the two sets of hydraulic control systems communicates with the second end of the third shuttle valve 133; the third end of the first shuttle valve 131 communicates with the second end of the second shuttle valve 132; the second end of the second shuttle valve 132 communicates; The third end of the second shuttle valve 132 communicates with the first end of the third shuttle valve 133, and the third end of the third shuttle valve 133 communicates with the feedback oil port of the variable displacement pump.
  • this embodiment is based on two sets of hydraulic control systems, which can simultaneously drive and control the operating mechanisms on the left and right sides of the operating machine, and each operating mechanism can realize the interlocking of the working mode and the floating mode in terms of control logic .
  • the hydraulic control system shown in this embodiment can respectively realize the control of the four floating modes of the operating mechanism, namely buffer floating, light-load floating, self-weight floating and heavy-load floating.
  • Figure 8 is a specific description.
  • the response threshold of the operating mechanism to the impact load can be increased by controlling the accumulator to maintain a relatively large initial pressure, while for roads with large impacts, By controlling the accumulator to maintain a relatively small initial pressure, the response threshold of the operating mechanism to the impact load can be reduced, so that the operating mechanism can adapt to different road conditions by adjusting the initial pressure of the accumulator.
  • the initial pressure of the pre-adjustment is set to be P3.
  • the intelligent display screen is used to perform corresponding control. The control steps are as follows:
  • the smart display prompts the operator to return the operating handle of the lift control valve to the neutral position, so that the lift control valve is in a cut-off state.
  • the smart display screen receives the operator’s input of the target value P3 for oil pressure regulation of the accumulator, controls the opening of the proportional pressure reducing valve, so that the oil pressure of the accumulator gradually approaches the target value P3, and controls the first
  • the upper position of the reversing valve is energized, so that the first reversing valve is in the second reversing state, and at the same time, the second on-off valve and the third on-off valve are opened, so that the hydraulic pump can charge hydraulic oil into the accumulator, and the accumulator
  • the oil pressure in the accumulator increases gradually; here, the smart display compares the pressure value P4 fed back by the first pressure sensor with P3, and when P3 is equal to P4, it indicates that the initial oil pressure of the accumulator reaches P3, and then the control Close the third on-off valve; then, close the second on-off valve, the first reversing valve and the proportional pressure reducing valve in sequence to complete the adjustment of the initial pressure of the accumulator.
  • the first on-off valve is controlled to be disconnected from the second on-off valve, the first reversing valve is de-energized, and the proportional decompression valve is de-energized.
  • the intelligent display screen select the control operation of the self-weight floating mode for the hydraulic control system; the intelligent display screen judges the conduction state of the second reversing valve based on the pressure value P fed back by the second pressure sensor.
  • the smart display screen controls the opening of the first on-off valve and the second on-off valve, and the first reversing valve and the proportional pressure reducing valve are powered off.
  • the rod cavity and the rodless cavity of the lifting cylinder are respectively connected with the oil tank, which can make the operating mechanism float with the road surface under the action of its own weight, and realize the floating obstacle avoidance of its own weight.
  • the smart display screen controls the first on-off valve to disconnect from the second on-off valve. The system does not enter the self-weight floating mode.
  • the smart display screen judges the conduction state of the second reversing valve according to the pressure signal fed back by the second pressure sensor. , to execute the self-weight floating mode command, otherwise not to execute.
  • the smart display detects that the second reversing valve enters the first reversing position or the second reversing position, the smart display will control the system to exit the self-weight floating mode.
  • this embodiment can prevent the system from starting the self-weight floating mode and the working mode at the same time, realize the interlocking of the control logic between the self-weight floating mode and the working mode, avoid causing the hydraulic system to be disordered, and improve the fault tolerance of the system.
  • the first on-off valve is controlled to be disconnected from the second on-off valve, the first reversing valve is de-energized, and the proportional decompression valve is de-energized.
  • the smart display is used for the operator to input the pressure target value of the rod cavity of the lifting cylinder; the smart display is based on the second pressure sensor feedback
  • the pressure value P is used to judge the conduction state of the second reversing valve.
  • the smart display screen controls the opening of the first on-off valve and the second on-off valve, and controls the lower position of the first reversing valve to be energized, so that the first reversing valve
  • the valve switches to the first reversing state
  • the hydraulic pump supplies oil to the rod cavity of the lifting cylinder
  • the hydraulic oil in the rodless cavity of the lifting cylinder returns to the oil tank
  • the opening of the proportional pressure reducing valve is adjusted to make the lifting cylinder
  • the oil pressure in the rod cavity reaches the target value
  • the oil pressure in the rod cavity of the lifting cylinder can offset part of the self-weight of the operating mechanism, so that the ground pressure of the operating mechanism can be adjusted steplessly within the range from 0 to the self-weight of the operating mechanism, realizing light load float.
  • the working mechanism When the working machine is working on a soft road surface, under the action of the working mechanism's own weight, the working mechanism will press deeper and deeper, resulting in excessive load and affecting the working efficiency and effect.
  • the operator can adjust the proportional decompression according to the construction road conditions. Valve, so that the operating mechanism has a suitable ground pressure to improve the operating efficiency and the leveling effect on the road surface.
  • the smart display screen controls the disconnection between the first on-off valve and the second on-off valve. open, and control the first reversing valve to be powered off, the proportional pressure reducing valve to be powered off, and the system exits the light-load floating mode.
  • the smart display screen controls the first on-off valve to disconnect from the second on-off valve. And control the power off of the first reversing valve and the power off of the proportional pressure reducing valve, so that the system does not enter the light-load floating mode.
  • the smart display screen judges the conduction state of the second reversing valve according to the pressure signal fed back by the second pressure sensor. , execute the light-load floating mode command, otherwise not execute.
  • the smart display detects that the second reversing valve enters the first reversing position or the second reversing position, the smart display will control the system to exit the light-load floating mode. Therefore, this embodiment can prevent the system from turning on the light-load floating mode and the working mode at the same time, realize the control logic interlock between the light-load floating mode and the working mode, avoid causing the hydraulic system to be disordered, and improve the fault tolerance of the system .
  • the first on-off valve is controlled to be disconnected from the second on-off valve, the first reversing valve is de-energized, and the proportional decompression valve is de-energized.
  • the smart display is used for the operator to input the pressure target value of the rodless chamber of the lifting cylinder; the smart display is based on the feedback from the second pressure sensor The pressure value P is used to judge the conduction state of the second reversing valve.
  • the smart display screen controls the opening of the first on-off valve and the second on-off valve, and controls the upper position of the first reversing valve to be energized, so that the first reversing valve
  • the valve switches to the second reversing state, the hydraulic pump supplies oil to the rodless chamber of the lifting cylinder, and the hydraulic oil in the rod chamber of the lifting cylinder returns to the oil tank, and the opening of the proportional pressure reducing valve is adjusted to make the lifting cylinder
  • the oil pressure in the rodless cavity reaches the target value, which can increase the ground pressing force of the operating mechanism and realize heavy-load floating.
  • the ice layer on the road surface cannot be crushed, and the deicing effect is poor.
  • the operator can adjust the proportional pressure reducing valve according to the condition of the construction road surface, adjust the appropriate ground pressure of the blade, and lift the Operating efficiency and deicing effect.
  • the smart display screen controls the disconnection between the first on-off valve and the second on-off valve. Open, and control the power off of the first reversing valve, power off of the proportional pressure reducing valve, and the system exits the heavy load floating mode.
  • the smart display screen controls the first on-off valve to disconnect from the second on-off valve. And control the power off of the first reversing valve and the power off of the proportional pressure reducing valve, so that the system does not enter the heavy-load floating mode.
  • the smart display screen judges the conduction state of the second reversing valve according to the pressure signal fed back by the second pressure sensor. , execute the overloaded floating mode command, otherwise not execute.
  • the smart display detects that the second reversing valve enters the first reversing position or the second reversing position, the smart display will control the system to exit the heavy-load floating mode. Therefore, this embodiment can prevent the system from starting the heavy-load floating mode and the working mode at the same time, realize the interlocking of the control logic between the heavy-load floating mode and the working mode, avoid causing the hydraulic system to be disordered, and improve the fault tolerance of the system .
  • the present application also provides a work machine, including the above-mentioned hydraulic control system.
  • the above working machine includes the above hydraulic control system, the above working machine has all the beneficial effects brought by the above hydraulic control system.
  • the above-mentioned working machine can be a grader, and the above-mentioned working mechanism can be a blade in the grader.

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Abstract

公开了一种液压控制系统，包括：液压泵（2）、油箱（1）、升降控制阀（4）及升降油缸（6）；液压泵（2）与油箱（1）通过升降控制阀（4）与升降油缸（6）连通，升降油缸（6）的伸缩端用于与作业机构连接；还包括浮动控制阀组（5）；浮动控制阀组（5）包括减压阀（52）与控制阀；液压泵（2）依次通过减压阀（52）及控制阀与升降油缸（6）连通；在控制阀处于第一状态的情况下，升降油缸的有杆腔与减压阀（52）连通，升降油缸的无杆腔与油箱（1）连通，在控制阀处于第二状态的情况下，浮动控制阀组所在的油路截止；可单独控制升降油缸工作于工作模式与轻载浮动模式，确保了作业机械运行的可靠性；还公开了包括该液压控制系统的作业机械。

Description

液压控制系统及作业机械
本申请要求于2021年09月09日提交的申请号为202122179928.9、发明名称为“液压控制系统及作业机械”的中国专利申请的优先权，其通过引用方式全部并入本文。
技术领域
本申请属于液压控制技术领域，涉及一种液压控制系统及作业机械。
背景技术
在进行平地施工的过程中，通过两套液压油路对升降油缸的工作状态进行控制，其中一套液压油路控制升降油缸正常地驱动铲刀的升降，另一套液压油路采用额外压力油源对升降油缸的有杆腔的油压进行控制，以抵消部分铲刀自重。但是，上述控制方案无法实现升降油缸的工作模式与浮动模式的调整，影响平地机的工作效率。
发明内容
本申请提供一种液压控制系统及作业机械，用以解决或者改善相关控制方案无法实现升降油缸的工作模式与浮动模式的调整，影响平地机的工作效率的技术问题。
本申请提供一种液压控制系统，包括：液压泵、油箱、升降控制阀、升降油缸及浮动控制阀组；所述升降控制阀用于控制所述升降油缸的有杆腔与无杆腔可选择性地与所述液压泵或所述油箱连通，所述升降油缸的伸缩端用于与作业机构连接；所述浮动控制阀组包括减压阀与控制阀；所述液压泵依次通过所述减压阀及所述控制阀与所述升降油缸连通；在所述控制阀处于第一状态的情况下，所述升降油缸的有杆腔与所述减压阀连通，所述升降油缸的无杆腔与所述油箱连通，在所述控制阀处于第二状态的情况下，所述浮动控制阀组所在的油路截止。
根据本申请提供的一种液压控制系统，在所述控制阀处于第三状态的情况下，所述升降油缸的无杆腔与所述减压阀连通，所述升降油缸的有杆腔与所述油箱连通；和/或，在所述控制阀处于第四状态的情况下，所述浮动控制阀组用于控制所述升降油缸的有杆腔与无杆腔分别与所述油箱连通。
根据本申请提供的一种液压控制系统，所述控制阀包括第一换向阀、 第一开关阀及第二开关阀；所述第一换向阀的进油口与所述减压阀连通，所述第一换向阀的其中一个工作油口通过所述第一开关阀与所述升降油缸的有杆腔连通，所述第一换向阀的另一个工作油口通过所述第二开关阀与所述升降油缸的无杆腔连通，所述第一换向阀的回油口与所述油箱连通。
根据本申请提供的一种液压控制系统，所述第一换向阀为电磁换向阀；所述减压阀为比例电磁减压阀；所述第一开关阀及所述第二开关阀中的至少一者为电磁开关阀；所述减压阀具有第一端口、第二端口及第三端口；所述第二端口可选择性地与所述第一端口或所述第三端口连通；所述第一端口与所述液压泵连通，所述第二端口与所述第一换向阀的进油口连通，所述第三端口与所述油箱连通。
根据本申请提供的一种液压控制系统，所述第一换向阀包括中位导通状态、第一换向状态及第二换向状态；在所述第一换向阀处于所述中位导通状态时，所述第一换向阀的进油口分别与所述第一换向阀的两个工作油口连通，所述升降油缸的有杆腔与所述升降油缸的无杆腔分别与所述油箱连通；在所述第一换向阀处于第一换向状态时，所述第一开关阀与所述第二开关阀连通，所述减压阀的第二端口与所述减压阀的第一端口连通，所述油箱依次通过所述减压阀、所述第一换向阀及所述第一开关阀与所述升降油缸的有杆腔连通，且所述升降油缸的无杆腔与所述油箱连通；在第一换向阀处于第二换向状态时，所述第一开关阀与所述第二开关阀连通，所述减压阀的第二端口与所述第一端口连通，所述油箱依次通过所述减压阀、所述第一换向阀及所述第二开关阀与所述升降油缸的无杆腔连通，所述升降油缸的有杆腔与所述油箱连通。
根据本申请提供的一种液压控制系统，还包括：蓄能器；所述蓄能器可选择性地与所述升降油缸的无杆腔连通。
根据本申请提供的一种液压控制系统，还包括：第一压力传感器与第三开关阀；所述第一压力传感器用于检测所述蓄能器的油压；所述蓄能器通过所述第三开关阀与所述升降油缸的无杆腔连通；所述第一压力传感器与所述第三开关阀通讯连接，以使得所述第三开关阀能够根据所述蓄能器的油压控制所述蓄能器与所述升降油缸的连通状态。
根据本申请提供的一种液压控制系统，所述第三开关阀为电磁开关阀。
根据本申请提供的一种液压控制系统，所述升降控制阀具有第一导通状态、第二导通状态、第三导通状态及第四导通状态；在所述升降控制阀处于第一导通状态的情况下，所述升降油缸的有杆腔与无杆腔分别与所述液压泵及所述油箱截止，所述浮动控制阀组对应的控制阀处于第一状态、 第三状态及第四状态中的任一种；在所述升降控制阀处于第二导通状态或第三导通状态的情况下，所述升降油缸的有杆腔与无杆腔中的一者与所述液压泵连通，以及所述有杆腔与所述无杆腔中的另一者与所述油箱连通，所述浮动控制阀组对应的控制阀处于第二状态；在所述升降控制阀处于第四导通状态的情况下，所述升降油缸的有杆腔与无杆腔分别与所述油箱连通，所述浮动控制阀组对应的控制阀处于第二状态。
根据本申请提供的一种液压控制系统，所述升降控制阀包括第二换向阀与压差阀；所述第二换向阀用于控制所述升降油缸的有杆腔与无杆腔可选择性地与所述液压泵或所述油箱连通；所述第二换向阀的其中一个工作油口与所述升降油缸的无杆腔之间的油路上设有第一阀锁，所述第二换向阀的另一个工作油口与所述升降油缸的有杆腔之间的油路上设有第二阀锁；所述压差阀的一端与所述第二换向阀内的液压锁开启油路连通，另一端分别与所述第一阀锁及所述第二阀锁连通；所述压差阀用于根据所述第二换向阀上油压同步控制所述第一阀锁与所述第二阀锁的导通状态。
根据本申请提供的一种液压控制系统，还包括：控制模块与第二压力传感器；所述第二压力传感器用于检测所述升降控制阀内液压锁开启油路的油压，所述第二压力传感器与所述控制模块通讯连接；所述控制模块与所述浮动控制阀组通讯连接。
根据本申请提供的一种液压控制系统，所述液压泵为变量泵；
在所述液压控制系统设为一套的情况下，所述浮动控制阀组与梭阀的第一端连通，所述梭阀的第二端与所述升降控制阀连通，所述梭阀的第三端与所述变量泵的反馈油口连通；
在所述液压控制系统设为两套的情况下，两套所述液压控制系统分别用于驱动控制设于作业机械左、右两侧的作业机构；两套所述液压控制系统共用一个所述变量泵；所述梭阀包括第一梭阀、第二梭阀及第三梭阀；两套所述液压控制系统的浮动控制阀组分别与所述第一梭阀的第一端与第二端连通，两套所述液压控制系统中一者的升降控制阀与所述第二梭阀的第一端连通，两套所述液压控制系统中另一者的升降控制阀与所述第三梭阀的第二端连通；所述第一梭阀的第三端与所述第二梭阀的第二端连通；所述第二梭阀的第三端与所述第三梭阀的第一端连通，所述第三梭阀的第三端与所述变量泵的反馈油口连通。
本申请还提供一种作业机械，包括如上所述的液压控制系统。
根据本申请提供的作业机械，所述作业机械为平地机，所述平地机的作业机构为铲刀。
本申请提供的一种液压控制系统及作业机械，液压控制系统包括液压泵、油箱、升降控制阀、浮动控制阀组及升降油缸，同一个液压泵提供的动力，分别通过升降控制阀与浮动控制阀组对升降油缸的作业工况进行控制；不仅可通过升降控制阀控制升降油缸正常地进行升降运动，以满足作业机构在正常工况下的作业需求，还可通过浮动控制阀组控制升降油缸处于轻载浮动状态，可以减小操作者劳动强度，提升作业效率与作业效果。由此可见，本申请所示的液压控制系统结构简单，成本低廉，可单独控制升降油缸工作于工作模式与轻载浮动模式，确保作业机械运行的可靠性。
附图说明
为了更清楚地说明本申请或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作一简单地介绍，显而易见地，下面描述中的附图是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是本申请提供的液压控制系统的结构示意图；
图2是本申请提供的控制模块分别与各个传感部件及执行部件相连接的结构示意图；
图3是本申请提供的升降控制阀的结构示意图；
图4是本申请提供的两套液压控制系统相连接的结构示意图；
图5是本申请提供的蓄能器初始蓄能压力调节的流程示意图；
图6是本申请提供的控制作业机构为自重浮动模式的流程示意图；
图7是本申请提供的控制作业机构为轻载浮动模式的流程示意图；
图8是本申请提供的控制作业机构为重载浮动模式的流程示意图；
附图标记：
1：油箱；           2：液压泵；          3：过滤器；
4：升降控制阀；     5：浮动控制阀组；    6：升降油缸；
7：蓄能器；         8：第三开关阀；      9：第一阀锁；
10：第二阀锁；      11：第一压力传感器； 12：第二压力传感器；
41：第二换向阀；    42：压差阀；         51：第一换向阀；
52：减压阀；        53：第一开关阀；     54：第二开关阀；
100：控制模块；     13：梭阀；           131：第一梭阀；
132：第二梭阀；     133：第三梭阀。
具体实施方式
为使本申请的目的、技术方案和优点更加清楚，下面将结合本申请中的附图，对本申请中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
下面结合图1-图8描述本申请的液压控制系统及作业机械。
如图1所示，本实施例提供一种液压控制系统，包括：液压泵2、油箱1、升降控制阀4及升降油缸6；液压泵2与油箱1通过升降控制阀4与升降油缸6连通，升降油缸6的伸缩端用于与作业机构连接。
其中，升降控制阀4用于控制升降油缸6的有杆腔与无杆腔可选择性地与液压泵2或油箱1连通。例如：在升降控制阀4控制升降油缸6的有杆腔与液压泵2连通时，升降油缸6的无杆腔与油箱1连通，如此可通过升降油缸6控制作业机构上升；在升降控制阀4控制升降油缸6的无杆腔与液压泵2连通时，升降油缸6的有杆腔与油箱1连通，通过升降油缸6控制作业机构下降；升降控制阀4也可控制升降油缸6的有杆腔与无杆腔分别与液压泵2及油箱1截止。
液压控制系统还设置有浮动控制阀组5；浮动控制阀组5包括减压阀52与控制阀；液压泵2依次通过减压阀52及控制阀与升降油缸6连通。控制阀用于控制升降油缸6的有杆腔与无杆腔可选择性地与减压阀52或油箱1连通；在控制阀处于第一状态的情况下，升降油缸6的有杆腔与减压阀52连通，升降油缸6的无杆腔与油箱1连通，在控制阀处于第二状态的情况下，浮动控制阀组5所在的油路截止。
通过设置液压泵2、油箱1、升降控制阀4、浮动控制阀组5及升降油缸6，可基于同一个液压泵2提供的动力，分别通过升降控制阀4与浮动控制阀组5对升降油缸6的作业工况进行控制；由于在控制阀处于第二状态时，浮动控制阀组所在的油路截止，液压控制系统可通过升降控制阀4控制升降油缸6进行升降运动，以满足作业机构在正常工况下的作业需求，而在升降控制阀4处于截止状态时，液压控制系统可通过浮动控制阀组5向升降油缸6的有杆腔充入液压油，以抵消作业机构的部分自重，从而控制升降油缸6处于轻载浮动状态，使得系统在轻载浮动模式作业时具有较低的能耗，提升作业效率与作业效果。
本实施例所示的液压控制系统结构简单，成本低廉，可单独控制升降油缸工作于工作模式与轻载浮动模式，无需额外压力油源，不仅结构简单、成本低廉，而且便于布置。
本实施例所示的控制阀可以理解为开关阀或开关阀与其它类型的阀构成的组合阀，以用于控制减压阀52与升降油缸6的有杆腔之间油路的导通或截止。
进一步地，本实施例所示的控制阀还具有第三状态与第四状态。在控制阀处于第三状态时，由于升降油缸6的无杆腔与减压阀52连通，升降油缸6的有杆腔与油箱1连通，液压泵2输出的液压油在经过减压阀52的减压处理后输送至升降油缸6的无杆腔，升降油缸6的有杆腔向油箱1回油，使得升降油缸6的无杆腔内的油压增大，以控制作业机构工作于重载浮动模式。
在升降控制阀4处于截止状态时，通过将控制阀切换至第四状态，可使得升降油缸6的有杆腔与无杆腔分别与油箱1连通，从而可通过升降油缸6控制作业机构工作于自重浮动模式。
本实施例所示的液压控制系还设置有过滤器3；液压泵2通过过滤器3与升降控制阀4连通。在此，过滤器3用于过滤液压系统的油液，确保进入液压系统的油液的清洁度。过滤器3包括过滤单元与旁通阀，旁通阀与过滤单元并联，旁通阀用于在过滤单元的滤芯出现堵塞时开启，防止对滤芯造成损伤。
如图1所示，控制阀包括第一换向阀51、第一开关阀53及第二开关阀54；第一换向阀51的进油口与减压阀连通，第一换向阀51的其中一个工作油口通过第一开关阀53与升降油缸6的有杆腔连通，第一换向阀51的另一个工作油口通过第二开关阀54与升降油缸6的无杆腔连通，第一换向阀51的回油口与油箱1连通。
其中，第一换向阀51为三位四通电磁换向阀。减压阀52为比例减压阀，比例减压阀优选为比例电磁减压阀。第一开关阀53及第二开关阀54中的至少一者为电磁开关阀。
与此同时，减压阀具有第一端口、第二端口及第三端口；第二端口可选择性地与第一端口或第三端口连通；第一端口与液压泵连通，第二端口与第一换向阀51的进油口连通，第三端口与油箱1连通。
具体而言，第一换向阀51具有中位导通状态、第一换向状态及第二换向状态。
在第一换向阀51处于中位导通状态时，第一换向阀51的进油口分别与第一换向阀51的两个工作油口导通，通过控制第一开关阀53与第二开关阀54导通，以及控制减压阀52的第二端口与第三端口连通，可使得升降油缸6的有杆腔与无杆腔分别与油箱1导通，可使得升降油缸6处于浮 动状态，以实现作业机构的自重浮动工作。
在第一换向阀51处于第一换向状态的情况下，通过控制第一开关阀53与第二开关阀54导通，以及控制减压阀52的第二端口与第一端口连通，液压泵2可将油箱1中的液压油依次通过减压阀52、第一换向阀51及第一开关阀53泵送至升降油缸6的有杆腔，且升降油缸6的无杆腔向油箱1回油，使得升降油缸6的有杆腔内的油压增强，以抵消作业机构的部分自重，实现作业机构的轻载浮动工作。
在第一换向阀51处于第二换向状态的情况下，通过控制第一开关阀53与第二开关阀54导通，以及控制减压阀52的第二端口与第一端口连通，液压泵2可将油箱1中的液压油依次通过减压阀52、第一换向阀51及第二开关阀54泵送至升降油缸6的无杆腔，升降油缸6的有杆腔向油箱1回油，使得升降油缸6的无杆腔的油压增强，以增大作业机构的压地力，实现作业机构的重载浮动工作。
为了便于控制作业机构进行缓冲浮动工作，液压控制系统还设置有蓄能器7；蓄能器7可选择性地与升降油缸6的无杆腔连通。
作业机构处于正常的作业模式，在对硬质路面等进行平地施工时，作业机构会受到很大冲击，通过将蓄能器7与升降油缸6的无杆腔连通，可利用蓄能器7吸收升降油缸6的无杆腔内的液压油，以减小作业机构的冲击载荷，实现缓冲浮动避障，提高作业机构的使用寿命。
进一步地，液压控制系统还设置有第一压力传感器11与第三开关阀8；第一压力传感器11用于检测蓄能器7的油压；蓄能器7通过第三开关阀8与升降油缸6的无杆腔连通；第一压力传感器11与第三开关阀8通讯连接，以使得第三开关阀8能够根据蓄能器7的油压控制蓄能器7与升降油缸6的连通状态。
如图1与图2所示，本实施例将第一压力传感器11与控制模块100通讯连接，并将控制模块100与第三开关阀8通讯连接。本实施例所示的第三开关阀8优选为电磁开关阀。控制模块100可以为本领域公知的人机交互模块，该人机交互模块不仅具有一定的逻辑运算能力，而且可以接受用户的参数指令输入，还可以实时进行数据显示。其中，人机交互模块可以为触摸屏控制器或具有逻辑判断能力的智能显示屏。
由此，在控制阀处于第四状态，以及减压阀的第一端口与第二端口连通时，本实施例所示的液压泵2可依次通过浮动控制阀组5及第三开关阀8向蓄能器7充注液压油。控制模块100依据第一压力传感器11所反馈的压力信号，通过控制第三开关阀8的开启与断开，来控制蓄能器7的初始 压力，实现对蓄能器7的不同初始蓄能压力的控制，从而调节对冲击载荷的响应阀值，兼顾减小冲击载荷与作业精度，提高了作业机械对不同硬度路面的适应性。
在实际操作中，操作者可以根据具体施工路面情况，对蓄能器7匹配相应的初始压力。对于冲击小的路面，可以控制蓄能器7保持相对较大的初始压力，增大作业机构对冲击载荷的响应阀值，保证作业机构有更大的压地力，减小冲击的同时提升作业平整度；对于冲击大的路面，可以控制蓄能器7保持相对较小的初始压力，降低作业机构对冲击载荷的响应阀值，保证作业机构有更小的压地力，以更大程度地减小冲击。
基于上述方案，本实施例所示的升降控制阀4具有第一导通状态、第二导通状态、第三导通状态及第四导通状态。
在升降控制阀4处于第一导通状态的情况下，升降油缸6的有杆腔与无杆腔分别与液压泵2及油箱1截止。由于升降油缸6的有杆腔与无杆腔均不能通过升降控制阀4通入液压油，升降控制阀4处于截止状态，此时，可控制浮动控制阀组5对应的控制阀处于第一状态、第三状态及第四状态中的任一种，以使得升降油缸6运行于浮动模式。在控制阀处于第一状态时，可控制升降油缸6为轻载浮动模式，在控制阀处于第三状态时，可控制升降油缸6为重载浮动模式，在控制阀处于第四状态时，可控制升降油缸6工为自重浮动模式。
在升降控制阀4处于第二导通状态或第三导通状态的情况下，升降油缸6的有杆腔与无杆腔中的一者与液压泵2连通，以及有杆腔与无杆腔中的另一者与油箱1连通。此时，升降控制阀4可控制升降油缸6的伸缩端进行正常地升降动作，升降控制阀4控制升降油缸6处于工作模式。为了防止升降油缸6的工作模式与浮动模式相互干扰，避免造成油路冲突，本实施例可控制浮动控制阀组5对应的控制阀处于第二状态，以使得浮动控制阀组所在的油路截止。
在升降控制阀4处于第四导通状态的情况下，升降油缸6的有杆腔与无杆腔分别与油箱1连通，浮动控制阀组5对应的控制阀处于第二状态。由于升降控制阀4控制升降油缸6的有杆腔与无杆腔分别与油箱1连通，且浮动控制阀组所在的油路截止，则可控制升降油缸6为自重浮动模式。
进一步地，升降控制阀4包括第二换向阀41；第二换向阀41包括手动换向阀；第二换向阀41的阀杆具有第一工位、第二工位、第三工位及第四工位。
在第二换向阀41处于第一工位(第二换向阀41处于中位)的情况下， 第二换向阀41内的液压锁开启油路闭合，以使得升降油缸6的有杆腔与无杆腔分别与液压泵2及油箱1截止。
在第二换向阀41处于第二工位的情况下，第二换向阀41内部的液压锁开启，以使得第二换向阀41可控制液压泵2与升降油缸6的无杆腔连通，以及油箱1与升降油缸6的有杆腔连通。此时，本实施例可通过第二换向阀41控制升降油缸6的伸缩端伸出，以控制作业机构下降。
在第二换向阀41处于第三工位的情况下，第二换向阀41内部的液压锁开启，以使得第二换向阀41用于控制液压泵2与升降油缸6的有杆腔连通，以及油箱1与升降油缸6的无杆腔连通。此时，本实施例可通过第二换向阀41控制升降油缸6的伸缩端回缩，以控制作业机构上升。
在第二换向阀41处于第四工位的情况下，第二换向阀41内部的液压锁开启，第二换向阀41可控制升降油缸6的有杆腔与无杆腔分别与油箱1连通，以及升降油缸6的有杆腔与无杆腔分别与液压泵2截止。第二换向阀41在此工况下，可控制作业机构工作于自重浮动模式，以使得作业机构在自重作用下随路面浮动，实现自重浮动避障。
在第二换向阀41为手动换向阀的情况下，可实现上述四个工位的手动切换，以通过手柄限位来实现系统的自重浮动模式与作业模式机械互锁，提高系统容错能力。
本实施例所示的升降控制阀4还包括压差阀42；第二换向阀41的其中一个工作油口与升降油缸6的无杆腔之间的油路上设有第一阀锁9，第二换向阀41的另一个工作油口与升降油缸6的有杆腔之间的油路上设有第二阀锁10；压差阀42的一端与第二换向阀41内的液压锁开启油路连通，另一端分别与第一阀锁9及第二阀锁10连通；压差阀42用于根据第二换向阀41上油压同步控制第一阀锁9与第二阀锁10的导通状态。
如图1与图3所示，第二换向阀41具有第一油口、第二油口、第三油口、第四油口、第五油口、第六油口及第七油口。其中，第一油口、第二油口、第三油口、第四油口、第五油口、第六油口及第七油口一一对应地以编号“A”、“B”、“C”、“D”、“E”、“F”、“G”进行标识。
图3所示的第二换向阀41为具有三个切换工位的换向阀，该第二换向阀41能够实现上述实施例所示的第一工位、第二工位及第三工位之间的相互切换。第二换向阀41也可选择包括上述实施例所示的第四工位的四个切换工位的换向阀。如此，在第二换向阀41处于第四工位时，通过控制升降油缸6的有杆腔与无杆腔分别与油箱1连通，同样可使得作业机构工作于自重浮动模式，以使得平地机在作业时实现自重浮动避障。
本实施例所示的第二换向阀41的第一油口与第二油口均作为工作油口，第二换向阀41的第一油口通过第二阀锁10与升降油缸6的有杆腔连通；第二换向阀41的第二油口通过第一阀锁9与升降油缸6的无杆腔连通；第二换向阀41的第三油口作为进油口，并与液压泵2连通；第二换向阀41的第四油口作为回油口，并与油箱1连通；第二换向阀41的第五油口与第六油口处于常通状态。
本实施例所示的第二换向阀41的第七油口分别与压差阀42的一端及先导端导通，压差阀42的另一端与第二换向阀41的第六油口连通。第二换向阀41的第六油口可选择性地与第二换向阀41的第一油口及第二油口中的任一者导通，在第二换向阀41的第六油口与第一油口导通时，第二换向阀41的第二油口与第四油口导通，而在第二换向阀41的第六油口与第二油口导通时，第二换向阀41的第一油口与第四油口导通。
第二换向阀41处于第一工位的情况下，第二换向阀41的第三油口与第七油口处于截止状态，压差阀42因其先导端没有通入液压油而处于截止状态，使得第一阀锁9与第二阀锁10均处于截止状态，即第二换向阀41与升降油缸6之间的油路不导通；而在第二换向阀41处于用于控制作业机构上升的第三工位或处于用于控制作业机构下降的第二工位时，由于第二换向阀41的第三油口与第七油口处于导通状态，压差阀42因其先导端通入有液压油而处于导通状态，使得第一阀锁9与第二阀锁10在油压的作用下处于导通状态，即第二换向阀41与升降油缸6之间的油路导通。
如图1与图2所示，本实施例所示的液压控制系统还设置有控制模块100与第二压力传感器12；第二压力传感器12用于检测升降控制阀4内液压锁开启油路的油压，第二压力传感器12与控制模块100通讯连接，控制模块100与浮动控制阀组5通讯连接。其中，本实施例所示的第二压力传感器12的检测端设于第二换向阀41的第六油口。
具体地，本实施例所示的第二压力传感器12用于检测升降控制阀4内部的液压锁开启油路的油压。由于在第二换向阀41处于第一工位时，第二换向阀41内部的液压锁关闭，压差阀42处于截止状态，使得第二换向阀41的第六油口没有建立油压，此时可通过第二压力传感器12检测到第二换向阀41内液压锁开启油路的油压小于P2，而在第二换向阀41处于第二工位、第三工位或第四工位时，第二换向阀41内液压锁开启油路的油压大于P1，且P1＞P2，则控制模块100可根据第二压力传感器12所反馈的压力信号，实现对第二换向阀41的导通状态的识别，并可根据第二换向阀41的导通状态对浮动控制阀组5的导通状态进行互锁控制。
本实施例基于第二压力传感器12反馈的压力信号，可对升降控制阀4的工作状态进行判定，从而基于升降控制阀4的实际工作状态，可相应地对浮动控制阀组5匹配相应的工作状态，以有选择地控制升降油缸6工作于作业状态、缓冲浮动状态、轻载浮动状态或自重浮动状态，进而降低了操作者的劳动强度，提升了作业机械的作业效率与作业效果。
本实施例基于对升降控制阀4与浮动控制阀组5的互锁控制，可实现升降油缸的工作模式与浮动模式的互锁，避免造成液压系统紊乱，提高了系统容错能力。
如图1所示，为了满足升降油缸在工作模式或浮动模式下的油压分配，确保液压控制系统运行的稳定性与可靠性，本实施例所示的系统还设有梭阀13；本实施例所示的液压泵2优选为变量泵。在此，本实施例设置梭阀13的第一端与浮动控制阀组5连通，梭阀13的第二端与升降控制阀4连通，梭阀13的第三端与变量泵的反馈油口连通。
其中，本实施例所示的梭阀的第一端具体与第一换向阀51的进油口连通，梭阀的第二端具体与第二换向阀41的第五油口连通。
进一步地，在对作业机械上的多个作业机构进行驱动控制的情况下，本实施例所示的液压控制系统可设置多套，多套液压控制系统与多个作业机构一一对应地连接。
如图4所示，本实施例所示的液压控制系统设有两套，分别用于驱动控制设于作业机械左、右两侧的作业机构；两套液压控制系统共用一个变量泵。
为了确保两套液压控制系统均能满足对相应的升降油缸6的控制需求，本实施例所示的梭阀13具体包括第一梭阀131、第二梭阀132及第三梭阀133；两套液压控制系统的浮动控制阀组5分别与第一梭阀131的第一端与第二端连通，两套液压控制系统中一者的升降控制阀4与第二梭阀132的第一端连通，两套液压控制系统中另一者的升降控制阀4与第三梭阀133的第二端连通；第一梭阀131的第三端与第二梭阀132的第二端连通；第二梭阀132的第三端与第三梭阀133的第一端连通，第三梭阀133的第三端与变量泵的反馈油口连通。如此，本实施例基于两套液压控制系统，可实现同时对作业机械左、右两侧的作业机构的驱动控制，且每个作业机构均可实现工作模式与浮动模式在控制逻辑上的互锁。
由上可知，基于上述方案，本实施例所示的液压控制系统可分别实现对作业机构的缓冲浮动、轻载浮动、自重浮动及重载浮动这四种浮动模式的控制，下面结合图5至图8进行具体说明。
在对作业机构执行缓冲浮动控制时，由于对于冲击小的路面，通过控制蓄能器保持相对较大的初始压力，可增大作业机构对冲击载荷的响应阀值，而对于冲击大的路面，通过控制蓄能器保持相对较小的初始压力，可降低作业机构对冲击载荷的响应阀值，从而可通过调节蓄能器的初始压力，以使得作业机构能够适应于不同的路面作业工况。
如图5所示，在进行蓄能器的初始压力的调控时，设定预调控的初始压力为P3，本实施例以智能显示屏执行相应的控制，其控制步骤如下：
首先，智能显示屏提示操作者将升降控制阀的操作手柄回中位，以使得升降控制阀处于截止状态。
接着，智能显示屏接收操作者对蓄能器执行油压调控的目标值P3的输入，控制比例减压阀的开度，以使得蓄能器的油压逐渐靠近目标值P3，并控制第一换向阀上位得电，以使得第一换向阀处于第二换向状态，同时，开启第二开关阀、第三开关阀，如此可使得液压泵向蓄能器内充注液压油，蓄能器内的油压逐渐增大；在此，智能显示屏将第一压力传感器反馈的压力值P4与P3进行比较，在P3等于P4时，表明蓄能器的初始油压达到P3，则控制关闭第三开关阀；接着，依次关闭第二开关阀、第一换向阀及比例减压阀，完成对蓄能器的初始压力的调节。
如图6所示，在对作业机构执行自重浮动控制时，操作步骤如下所示：
首先，在开机时，控制第一开关阀与第二开关阀断开，第一换向阀断电，比例减压阀断电。
然后，在智能显示屏上选择对液压控制系统执行自重浮动模式的控制操作；智能显示屏基于第二压力传感器反馈的压力值P，对第二换向阀的导通状态进行判断。
在压力值P小于P2时，可判断第二换向阀处于中位，智能显示屏控制开启第一开关阀与第二开关阀，第一换向阀与比例减压阀断电，此时，升降油缸的有杆腔与无杆腔分别与油箱连通，可使得作业机构在自重作用下随路面浮动，实现自重浮动避障。在对第二压力传感器反馈的信号进行继续监测的过程中，若出现压力值P大于P1，则表明第二换向阀不处于中位，智能显示屏控制第一开关阀与第二开关阀断开，系统退出自重浮动模式。
在对第二压力传感器反馈的信号进行初始监测时，若出现压力值P大于P1，则表明第二换向阀不处于中位，智能显示屏控制第一开关阀与第二开关阀断开，系统不进入自重浮动模式。
在整个控制流程中，在系统进入自重浮动模式之前，智能显示屏根据第二压力传感器反馈的压力信号，对第二换向阀的导通状态进行判断，在 第二换向阀处于中位时，执行自重浮动模式命令，否则不执行。当系统处于自重浮动模式的情况下，在智能显示屏监测到第二换向阀进入第一换向工位或第二换向工位时，智能显示屏会控制系统退出自重浮动模式。由此，本实施例可防止系统同时开启自重浮动模式与作业模式，实现自重浮动模式与作业模式之间的控制逻辑上的互锁，避免导致造成液压系统紊乱，提高了系统的容错能力。
如图7所示，在对作业机构执行轻载浮动控制时，操作步骤如下所示：
首先，在开机时，控制第一开关阀与第二开关阀断开，第一换向阀断电，比例减压阀断电。
然后，在智能显示屏上选择对液压控制系统执行轻载浮动模式的控制操作，智能显示屏用于供操作者输入升降油缸的有杆腔的压力目标值；智能显示屏基于第二压力传感器反馈的压力值P，对第二换向阀的导通状态进行判断。
在压力值P小于P2时，可判断第二换向阀处于中位，智能显示屏控制开启第一开关阀与第二开关阀，控制第一换向阀下位得电，以使得第一换向阀切换至第一换向状态，液压泵向升降油缸的有杆腔供油，升降油缸的无杆腔的液压油返回至油箱，并通过调节比例减压阀的开度，以使得升降油缸的有杆腔的油压达到目标值，升降油缸的有杆腔内的油压可以抵消作业机构的部分自重，从而实现作业机构的压地力在0至作业机构的自重区间内无级调节，实现轻载浮动。由于作业机械在软路面施工时，在作业机构的自重的作用下，作业机构会越压越深，导致负载过大，影响作业效率及作业效果，操作者可以根据施工路面情况，调节比例减压阀，以使得作业机构具有合适的压地力，以提升作业效率及对路面的平整效果。
在对第二压力传感器反馈的信号进行继续监测的过程中，若出现压力值P大于P1，则表明第二换向阀不处于中位，智能显示屏控制第一开关阀与第二开关阀断开，并控制第一换向阀断电、比例减压阀断电，系统退出轻载浮动模式。
在对第二压力传感器反馈的信号进行初始监测时，若出现压力值P大于P1，则表明第二换向阀不处于中位，智能显示屏控制第一开关阀与第二开关阀断开，并控制第一换向阀断电、比例减压阀断电，系统不进入轻载浮动模式。
在整个控制流程中，在系统进入轻载浮动模式之前，智能显示屏根据第二压力传感器反馈的压力信号，对第二换向阀的导通状态进行判断，在第二换向阀处于中位时，执行轻载浮动模式命令，否则不执行。当系统处 于轻载浮动模式的情况下，在智能显示屏监测到第二换向阀进入第一换向工位或第二换向工位时，智能显示屏会控制系统退出轻载浮动模式。由此，本实施例可防止系统同时开启轻载浮动模式与作业模式，实现轻载浮动模式与作业模式之间的控制逻辑上的互锁，避免导致造成液压系统紊乱，提高了系统的容错能力。
如图8所示，在对作业机构执行重载浮动控制时，操作步骤如下所示：
首先，在开机时，控制第一开关阀与第二开关阀断开，第一换向阀断电，比例减压阀断电。
然后，在智能显示屏上选择对液压控制系统执行重载浮动模式的控制操作，智能显示屏用于供操作者输入升降油缸的无杆腔的压力目标值；智能显示屏基于第二压力传感器反馈的压力值P，对第二换向阀的导通状态进行判断。
在压力值P小于P2时，可判断第二换向阀处于中位，智能显示屏控制开启第一开关阀与第二开关阀，控制第一换向阀上位得电，以使得第一换向阀切换至第二换向状态，液压泵向升降油缸的无杆腔供油，升降油缸的有杆腔的液压油返回至油箱，并通过调节比例减压阀的开度，以使得升降油缸的无杆腔的油压达到目标值，可以增加作业机构的压地力，实现重载浮动。在除冰作业时，在作业机构的自重的作用下，无法压碎路面冰层，除冰效果差，操作者可以根据施工路面情况，调节比例减压阀，调节合适的铲刀压地力，提升作业效率及除冰效果。
在对第二压力传感器反馈的信号进行继续监测的过程中，若出现压力值P大于P1，则表明第二换向阀不处于中位，智能显示屏控制第一开关阀与第二开关阀断开，并控制第一换向阀断电、比例减压阀断电，系统退出重载浮动模式。
在对第二压力传感器反馈的信号进行初始监测时，若出现压力值P大于P1，则表明第二换向阀不处于中位，智能显示屏控制第一开关阀与第二开关阀断开，并控制第一换向阀断电、比例减压阀断电，系统不进入重载浮动模式。
在整个控制流程中，在系统进入重载浮动模式之前，智能显示屏根据第二压力传感器反馈的压力信号，对第二换向阀的导通状态进行判断，在第二换向阀处于中位时，执行重载浮动模式命令，否则不执行。当系统处于重载浮动模式的情况下，在智能显示屏监测到第二换向阀进入第一换向工位或第二换向工位时，智能显示屏会控制系统退出重载浮动模式。由此，本实施例可防止系统同时开启重载浮动模式与作业模式，实现重载浮动模 式与作业模式之间的控制逻辑上的互锁，避免导致造成液压系统紊乱，提高了系统的容错能力。
优选地，本申请还提供一种作业机械，包括上述液压控制系统。
由于上述作业机械包括上述液压控制系统，因此上述作业机械具有上述液压控制系统所带来的所有有益效果。
在此应指出的是，上述作业机械可以为平地机，上述作业机构可以为平地机中的铲刀。
最后应说明的是：以上实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的精神和范围。

Claims (13)

  1. 一种液压控制系统，包括：液压泵、油箱、升降控制阀、升降油缸及浮动控制阀组；所述升降控制阀用于控制所述升降油缸的有杆腔与无杆腔可选择性地与所述液压泵或所述油箱连通，所述升降油缸的伸缩端用于与作业机构连接；所述浮动控制阀组包括减压阀与控制阀；所述液压泵依次通过所述减压阀及所述控制阀与所述升降油缸连通；在所述控制阀处于第一状态的情况下，所述升降油缸的有杆腔与所述减压阀连通，所述升降油缸的无杆腔与所述油箱连通，在所述控制阀处于第二状态的情况下，所述浮动控制阀组所在的油路截止。
  2. 根据权利要求1所述的液压控制系统，其中，
    在所述控制阀处于第三状态的情况下，所述升降油缸的无杆腔与所述减压阀连通，所述升降油缸的有杆腔与所述油箱连通；和/或，在所述控制阀处于第四状态的情况下，所述浮动控制阀组用于控制所述升降油缸的有杆腔与无杆腔分别与所述油箱连通。
  3. 根据权利要求2所述的液压控制系统，其中，
    所述控制阀包括第一换向阀、第一开关阀及第二开关阀；
    所述第一换向阀的进油口与所述减压阀连通，所述第一换向阀的其中一个工作油口通过所述第一开关阀与所述升降油缸的有杆腔连通，所述第一换向阀的另一个工作油口通过所述第二开关阀与所述升降油缸的无杆腔连通，所述第一换向阀的回油口与所述油箱连通。
  4. 根据权利要求3所述的液压控制系统，其中，
    所述第一换向阀为电磁换向阀；所述减压阀为比例电磁减压阀；所述第一开关阀及所述第二开关阀中的至少一者为电磁开关阀；
    所述减压阀具有第一端口、第二端口及第三端口；所述减压阀的第二端口可选择性地与所述减压阀的第一端口或所述减压阀的第三端口连通；所述减压阀的第一端口与所述液压泵连通，所述减压阀的第二端口与所述第一换向阀的进油口连通，所述减压阀的第三端口与所述油箱连通。
  5. 根据权利要求3所述的液压控制系统，其中，所述第一换向阀包括中位导通状态、第一换向状态及第二换向状态；
    在所述第一换向阀处于所述中位导通状态时，所述第一换向阀的进油口分别与所述第一换向阀的两个工作油口连通，所述升降油缸的有杆腔与所述升降油缸的无杆腔分别与所述油箱连通；
    在所述第一换向阀处于第一换向状态时，所述第一开关阀与所述第二 开关阀连通，所述减压阀的第二端口与所述减压阀的第一端口连通，所述油箱依次通过所述减压阀、所述第一换向阀及所述第一开关阀与所述升降油缸的有杆腔连通，且所述升降油缸的无杆腔与所述油箱连通；
    在第一换向阀处于第二换向状态时，所述第一开关阀与所述第二开关阀连通，所述减压阀的第二端口与所述第一端口连通，所述油箱依次通过所述减压阀、所述第一换向阀及所述第二开关阀与所述升降油缸的无杆腔连通，所述升降油缸的有杆腔与所述油箱连通。
  6. 根据权利要求1所述的液压控制系统，其中，
    还包括：蓄能器；
    所述蓄能器可选择性地与所述升降油缸的无杆腔连通；
    还包括：第一压力传感器与第三开关阀；
    所述第一压力传感器用于检测所述蓄能器的油压；所述蓄能器通过所述第三开关阀与所述升降油缸的无杆腔连通；
    所述第一压力传感器与所述第三开关阀通讯连接，以使得所述第三开关阀能够根据所述蓄能器的油压控制所述蓄能器与所述升降油缸的连通状态。
  7. 根据权利要求6所述的液压控制系统.其中，所述第三开关阀为电磁开关阀。
  8. 根据权利要求2至7任一所述的液压控制系统，其中，
    所述升降控制阀具有第一导通状态、第二导通状态、第三导通状态及第四导通状态；
    在所述升降控制阀处于第一导通状态的情况下，所述升降油缸的有杆腔与所述液压泵截止，所述升降油缸的无杆腔与所述油箱截止，所述浮动控制阀组对应的控制阀处于第一状态、第三状态及第四状态中的任一种；
    在所述升降控制阀处于第二导通状态或第三导通状态的情况下，所述升降油缸的有杆腔与无杆腔中的一者与所述液压泵连通，以及所述有杆腔与所述无杆腔中的另一者与所述油箱连通，所述浮动控制阀组对应的控制阀处于第二状态；
    在所述升降控制阀处于第四导通状态的情况下，所述升降油缸的有杆腔与无杆腔分别与所述油箱连通，所述浮动控制阀组对应的控制阀处于第二状态。
  9. 根据权利要求8所述的液压控制系统，其中，
    所述升降控制阀包括第二换向阀与压差阀；
    所述第二换向阀的其中一个工作油口与所述升降油缸的无杆腔之间的 油路上设有第一阀锁，所述第二换向阀的另一个工作油口与所述升降油缸的有杆腔之间的油路上设有第二阀锁；
    所述压差阀的一端与所述第二换向阀内的液压锁开启油路连通，另一端分别与所述第一阀锁及所述第二阀锁连通；所述压差阀用于根据所述第二换向阀上油压同步控制所述第一阀锁与所述第二阀锁的导通状态。
  10. 根据权利要求1至7任一所述的液压控制系统，其中，
    还包括：控制模块与第二压力传感器；
    所述第二压力传感器用于检测所述升降控制阀内液压锁开启油路的油压，所述第二压力传感器与所述控制模块通讯连接，所述控制模块与所述浮动控制阀组通讯连接。
  11. 根据权利要求1至7任一所述的液压控制系统，其中，
    所述液压泵为变量泵；
    在所述液压控制系统设为一套的情况下，所述浮动控制阀组与梭阀的第一端连通，所述梭阀的第二端与所述升降控制阀连通，所述梭阀的第三端与所述变量泵的反馈油口连通；
    在所述液压控制系统设为两套的情况下，两套所述液压控制系统分别用于驱动控制设于作业机械左、右两侧的作业机构；两套所述液压控制系统共用一个所述变量泵；所述梭阀包括第一梭阀、第二梭阀及第三梭阀；两套所述液压控制系统的浮动控制阀组分别与所述第一梭阀的第一端与第二端连通，两套所述液压控制系统中一者的升降控制阀与所述第二梭阀的第一端连通，两套所述液压控制系统中另一者的升降控制阀与所述第三梭阀的第二端连通；所述第一梭阀的第三端与所述第二梭阀的第二端连通；所述第二梭阀的第三端与所述第三梭阀的第一端连通，所述第三梭阀的第三端与所述变量泵的反馈油口连通。
  12. 一种作业机械，包括如权利要求1至11任一所述的液压控制系统。
  13. 根据权利要求12所述的作业机械，其中，所述作业机械为平地机，所述平地机的作业机构为铲刀。
PCT/CN2022/081262 2021-09-09 2022-03-16 液压控制系统及作业机械 WO2023035583A1 (zh)

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