Hydraulic control system and working machine

Abstract

The present application relates to the technical field of engineering machinery, and provides a hydraulic control system and a working machine, the hydraulic control system comprising a hydraulic device for driving the working device of the working machine to act, a main valve for controlling the hydraulic device, a pilot pump, a hand valve, an electric control valve, a pressure detection element for detecting the oil pressure of the hand valve, an input module for setting the opening degree of the electric control valve, and a controller, the hand valve being communicated with the pilot oil port of the pilot pump and the main valve; the electric control valve being communicated with the pilot oil port of the pilot pump and the main valve; the controller being in communication connection with the electric control valve, the pressure detection element and the input module, and the controller controlling the opening degree of the electric control valve according to the detection signal of the pressure detection element and / or the input signal of the input module. The hand valve, the solenoid valve, the pressure detection element and the input module can realize the separate manual control, the separate electric control and the manual and electric common control of the main valve, and the linear input of the electric control valve can be adjusted in advance of the hand valve through the direct communication of the electric control valve with the pilot oil port of the pilot pump and the main valve.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of construction machinery, and in particular to a hydraulic control system and a working machine. BACKGROUND

[0002] With the continuous development of construction machinery, the application of electric control technology in construction machinery is becoming more and more widespread. For example, the electric control main valve of the excavator gradually replaces the hydraulic control main valve. The working conditions of the excavator are diverse, and the speed of mutual cooperation of the boom, stick and bucket is different under each working condition. Therefore, the control system of the excavator needs to cope with different working conditions. The driver often needs the fast response of the excavator to meet the needs of special working conditions, such as the continuous switching of a certain action in the soil screening working condition and the ground leveling working condition, and achieves the purpose of completing the work through response impact, thereby increasing the operation difficulty of the driver.

[0003] In the prior art, in order to reduce the operation difficulty of the driver and improve the production efficiency, the boom control main valve, the bucket control main valve, the stick control main valve and the rotary control main valve are all connected in parallel on the working oil circuit of the plunger variable pump, and the pilot oil pump is connected to the pilot hydraulic control ends of the above-mentioned control main valves and the operating handle. Proportional solenoid valves are arranged on the oil circuit between the pilot hydraulic control ends of the control main valves and the operating handle, so that the inlet and outlet oil circuits of the proportional solenoid valves are respectively connected to the pilot hydraulic control ends of the above-mentioned control main valves and the working oil ports of the operating handle. Then, the opening of the proportional solenoid valve is controlled by the controller, so that the proportional solenoid valve can adapt to different working conditions.

[0004] However, since the proportional solenoid valve is arranged on the oil circuit between the pilot hydraulic control end of the main valve and the operating handle, the linear input of the proportional solenoid valve cannot be adjusted before the handle, and the main valve cannot be controlled by the proportional solenoid valve only without the operation of the pilot handle. SUMMARY

[0005] The present application provides a hydraulic control system and a working machine to solve the defect that the proportional solenoid valve is arranged on the oil circuit between the pilot hydraulic control end of the main valve and the operating handle, so that the linear input of the proportional solenoid valve cannot be adjusted before the handle, and the main valve cannot be controlled by the proportional solenoid valve only without the operation of the pilot handle.

[0006] The present application provides a hydraulic control system, comprising:

[0007] a hydraulic device for driving the working device of the working machine to act;

[0008] a main valve for controlling the hydraulic device;

[0009] a pilot pump, an oil inlet of the pilot pump being communicated with an oil tank;

[0010] a hand valve, an inlet of the hand valve being communicated with an outlet of the pilot pump, an outlet of the hand valve being communicated with a pilot oil port of the main valve;

[0011] an electric control valve, an inlet of the electric control valve being communicated with the outlet of the pilot pump, an outlet of the electric control valve being communicated with the pilot oil port of the main valve;

[0012] a pressure detecting element for detecting an outlet pressure of the hand valve;

[0013] an input module for setting an opening degree of the electric control valve;

[0014] a controller, which is communicatively connected with the electric control valve, the pressure detecting element and the input module, and controls the opening degree of the electric control valve according to a detection signal of the pressure detecting element and / or an input signal of the input module.

[0015] According to the hydraulic control system provided by the present application, the hydraulic control system further comprises:

[0016] a pressure reducing valve, which is arranged between the hand valve and the pilot oil port of the main valve, and has an output pressure less than a pressure at which a spool of the main valve is switched to a working position.

[0017] According to the hydraulic control system provided by the present application, the hydraulic control system further comprises:

[0018] a relief valve, which is connected with a return port of the electric control valve, and has a return port connected with the oil tank, and has a set pressure greater than or equal to the output pressure of the pressure reducing valve;

[0019] wherein, when the pressure of the pilot oil return of the main valve is less than the output pressure of the pressure reducing valve, the pilot oil return flows back to the oil tank through the pressure reducing valve and the hand valve;

[0020] when the pressure of the pilot oil return of the main valve is greater than or equal to the output pressure of the pressure reducing valve, the pilot oil return flows back to the oil tank through the electric control valve and the relief valve.

[0021] According to the hydraulic control system provided by the present application, the hand valve comprises a first hand valve and a second hand valve, the electric control valve comprises a first electric control valve and a second electric control valve, an inlet of the first hand valve and an inlet of the first electric control valve are both communicated with the outlet of the pilot pump, an outlet of the first hand valve and an outlet of the first electric control valve are both communicated with a first pilot oil port of the main valve; an outlet of the second hand valve and an outlet of the second electric control valve are both communicated with a second pilot oil port of the main valve.

[0022] According to the hydraulic control system provided by the application, the pressure detection element comprises a first pressure detection element and a second pressure detection element, the first pressure detection element is used for detecting the oil outlet pressure of the first hand valve, and the second pressure detection element is used for detecting the oil outlet pressure of the second hand valve.

[0023] The controller controls the opening degree of the first electric control valve according to the detection signal of the first pressure detection element and / or the input signal of the input module.

[0024] The controller controls the opening degree of the second electric control valve according to the detection signal of the second pressure detection element and / or the input signal of the input module.

[0025] According to the hydraulic control system provided by the application, the pressure reduction valve comprises:

[0026] The first pressure reduction valve is arranged between the first hand valve and the first pilot oil port of the main valve, and the output pressure of the first pressure reduction valve is less than the pressure at which the spool of the main valve is switched to the first working position.

[0027] The second pressure reduction valve is arranged between the second hand valve and the second pilot oil port of the main valve, and the output pressure of the second pressure reduction valve is less than the pressure at which the spool of the main valve is switched to the second working position.

[0028] According to the hydraulic control system provided by the application, the pressure reduction valve comprises:

[0029] The first overflow valve is connected with the oil return port of the first electric control valve, the oil return port of the first overflow valve is connected with the oil tank, and the set pressure of the first overflow valve is greater than the output pressure of the first pressure reduction valve.

[0030] The second overflow valve is connected with the oil return port of the second electric control valve, the oil return port of the second overflow valve is connected with the oil tank, and the set pressure of the second overflow valve is greater than the output pressure of the second pressure reduction valve.

[0031] According to the hydraulic control system provided by the application, the hydraulic device is one of a boom cylinder, a stick cylinder, a bucket cylinder and a swing motor.

[0032] The hydraulic control system provided by the application comprises a hydraulic device, a main valve, a pilot pump, a hand valve and an electric control valve.

[0033] The application further provides a working machine comprising the hydraulic control system according to any one of the above.

[0034] The hydraulic control system and the working machine provided by the application are characterized in that the hydraulic control system comprises a hydraulic device, a main valve, a pilot pump, a hand valve and an electric control valve, the hydraulic device is used to drive a working device of the working machine to act to realize corresponding work, the main valve is used to control the hydraulic device to drive the working device of the working machine to act, an oil inlet of the pilot pump is communicated with an oil tank, an oil inlet of the hand valve is communicated with an oil outlet of the pilot pump, an oil outlet of the hand valve is communicated with a pilot oil inlet of the main valve, the pilot oil supplied to the main valve can be regulated and controlled through the hand valve, thereby realizing manual control of the main valve, an oil inlet of the electric control valve is communicated with the oil outlet of the pilot pump, and an oil outlet of the electric control valve is communicated with the pilot oil inlet of the main valve, the pilot oil supplied to the main valve can be regulated and controlled through the electric control valve, thereby realizing electric control of the main valve.

[0035] The hydraulic control system further comprises a pressure detection element, an input module and a controller, the pressure detection element is used to detect an oil outlet pressure of the hand valve, the input module is used to set an opening degree of the electric control valve, the controller is in communication connection with the electric control valve, the pressure detection element and the input module respectively, and the controller controls the opening degree of the electric control valve according to a detection signal of the pressure detection element and / or an input signal of the input module, that is, the electric control valve can achieve linear input in different modes according to the pilot signal output by the hand valve, and the electric control valve can also achieve linear input in different modes according to the input signal of the input module.

[0036] In this way, the hand valve can be used to realize separate manual control of the main valve, the electric control valve can be used to realize separate electric control of the main valve, the initial pressure output by the hand valve to the main valve is controlled to move the valve core of the main valve by a certain distance, then the oil outlet pressure of the hand valve is detected by the pressure detection element to control the electric control valve to output the pilot oil to the main valve to regulate and control the main valve, so that the valve core of the main valve can respond quickly, and the main valve can be quickly switched to the working position, that is, the hand valve and the electric control valve can be used to realize common control of the main valve.

[0037] In addition, the linear input of the electric control valve can be adjusted prior to the hand valve by directly connecting the electric control valve with the pilot port of the pilot pump and the main valve, and the operation intention can be judged in real time by the pressure detecting element and the electric control valve can be linearly optimized.

[0038] The hydraulic control system further comprises a pressure reducing valve arranged between the hand valve and the pilot port of the main valve, and the output pressure of the pressure reducing valve is less than the pressure at which the spool of the main valve is switched to the working position. In this way, when the main valve is regulated, the operator can output an initial pressure to the main valve through the hand valve, so that the spool of the main valve is moved by a certain distance, and when the electric control valve is used to regulate the main valve, the spool of the main valve can quickly respond, so that the main valve can be quickly switched to the working position.

[0039] The hydraulic control system further comprises an overflow valve connected with the oil return port of the electric control valve, and the oil return port of the overflow valve is connected with the oil tank, and the set pressure of the overflow valve is greater than or equal to the output pressure of the pressure reducing valve. When the pressure of the pilot oil return of the main valve is less than the output pressure of the pressure reducing valve, the pilot oil return flows back to the oil tank through the pressure reducing valve and the hand valve; when the pressure of the pilot oil return of the main valve is greater than or equal to the output pressure of the pressure reducing valve, the pilot oil return flows back to the oil tank through the electric control valve and the overflow valve. In this way, the pilot oil can be returned at a constant pressure by the cooperation of the pressure reducing valve and the overflow valve. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative effort.

[0041] Figure 1 is a structural schematic diagram of the hydraulic control system provided by the present application.

[0042] Reference signs:

[0043] 1, oil tank; 2, engine; 3, main pump;

[0044] 4, pilot pump; 5, main valve; 6, hydraulic device;

[0045] 7, first hand valve; 8, second hand valve; 9, first electric control valve;

[0046] 10, second electric control valve; 11, first pressure reducing valve; 12, second pressure reducing valve;

[0047] 13, first overflow valve; 14, second overflow valve; 15, first pressure detecting element;

[0048] 16 second pressure detecting element; 17 third overflow valve. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0050] The hydraulic control system and the working machine of the present application will be described below. Figure 1 The hydraulic control system and the working machine of the present application will be described below.

[0051] The hydraulic control system provided by the present application can include a hydraulic device 6, a main valve 5, a pilot pump 4, a hand valve and an electric control valve.

[0052] The hydraulic device 6 can be used to drive the working device of the working machine to act, so as to realize corresponding work.

[0053] The main valve 5 can be used to control the hydraulic device 6, so that the hydraulic device 6 drives the working device of the working machine to act.

[0054] The oil inlet of the pilot pump 4 can be communicated with the oil tank 1, the oil inlet of the hand valve can be communicated with the oil outlet of the pilot pump 4, and the oil outlet of the hand valve can be communicated with the pilot oil inlet of the main valve 5. In this way, the pilot oil supplied to the main valve 5 can be regulated through the hand valve, so that manual control of the main valve 5 can be realized. The oil inlet of the electric control valve can be communicated with the oil outlet of the pilot pump 4, and the oil outlet of the electric control valve can be communicated with the pilot oil inlet of the main valve 5. In this way, the pilot oil supplied to the main valve 5 can be regulated through the electric control valve, so that electric control of the main valve 5 can be realized.

[0055] In addition, the hydraulic control system can further include a pressure detecting element, an input module and a controller.

[0056] The pressure detecting element can be used to detect the oil outlet pressure of the hand valve, the input module can be used to set the opening degree of the electric control valve, and the controller can be in communication connection with the electric control valve, the pressure detecting element and the input module respectively. The controller can control the opening degree of the electric control valve according to the detection signal of the pressure detecting element and / or the input signal of the input module, that is, the electric control valve can achieve linear input in different modes according to the pilot signal output by the hand valve, and the electric control valve can also achieve linear input in different modes according to the input signal of the input module.

[0057] Here, the electric control valve can be a solenoid valve.

[0058] In this way, the hand valve, the solenoid valve, the pressure detecting element and the input module can realize the separate manual control of the main valve 5, the separate electric control of the main valve 5, and the manual and electric common control of the main valve 5, and the linear input of the electric control valve can be adjusted in advance of the hand valve through the direct connection of the electric control valve with the pilot port of the pilot pump 4 and the main valve 5, and the operation intention can be judged in real time through the pressure detecting element and the electric control valve can be linearly optimized.

[0059] In the optional embodiment of the present application, the hand valve can include a first hand valve 7 and a second hand valve 8, the electric control valve can include a first electric control valve 9 and a second electric control valve 10, the oil inlet of the first hand valve 7 and the oil inlet of the first electric control valve 9 can be communicated with the oil outlet of the pilot pump 4, and the oil outlet of the first hand valve 7 and the oil outlet of the first electric control valve 9 can be communicated with the first pilot port of the main valve 5; the oil inlet of the second hand valve 8 and the oil inlet of the second electric control valve 10 can be communicated with the oil outlet of the pilot pump 4, and the oil outlet of the second hand valve 8 and the oil outlet of the second electric control valve 10 can be communicated with the second pilot port of the main valve 5. In this way, the first hand valve 7 and the first electric control valve 9 can control the spool of the main valve 5 to switch to the first working position, and the second hand valve 8 and the second electric control valve 10 can control the spool of the main valve 5 to switch to the second working position.

[0060] In addition, the pressure detecting element can include a first pressure detecting element 15 and a second pressure detecting element 16, the first pressure detecting element 15 can be used to detect the oil outlet pressure of the first hand valve 7, and the second pressure detecting element 16 can be used to detect the oil outlet pressure of the second hand valve 8.

[0061] The controller can control the opening degree of the first electric control valve 9 according to the detection signal of the first pressure detecting element 15 and / or the input signal of the input module.

[0062] The controller can control the opening degree of the second electric control valve 10 according to the detection signal of the second pressure detecting element 16 and / or the input signal of the input module.

[0063] Here, the input module can be a human-machine interface, specifically, the input module can be a touch screen arranged in the cab of the engineering machinery.

[0064] The first pressure detecting element 15 and the second pressure detecting element 16 can both be pressure sensors.

[0065] In an optional embodiment of the present invention, the hydraulic control system may further include a pressure reducing valve, which may be disposed between the pilot port of the hand valve and the main valve 5, and the output pressure of the pressure reducing valve may be less than the pressure required for the valve core of the main valve 5 to switch to the working position. Thus, when regulating the main valve 5, the operator can first supply an initial pressure to the main valve 5 through the hand valve, causing the valve core of the main valve 5 to move a certain distance, so that when the electronically controlled valve regulates the main valve 5, the valve core of the main valve 5 can respond quickly, enabling the main valve 5 to quickly switch to the working position.

[0066] In an optional embodiment, the pressure reducing valve may include a first pressure reducing valve 11 and a second pressure reducing valve 12. The first pressure reducing valve 11 may be disposed between the first pilot port of the first hand valve 7 and the first pilot port of the main valve 5, and the second pressure reducing valve 12 may be disposed between the second hand valve 8 and the second pilot port of the main valve 5.

[0067] Furthermore, the output pressure of the first pressure reducing valve 11 can be less than the pressure required for the valve core of the main valve 5 to switch to the first working position. In this way, when the main valve 5 is controlled, the operator can first output an initial pressure to the main valve 5 through the first manual valve 7, so that the valve core of the main valve 5 moves a certain distance. This allows the valve core of the main valve 5 to respond quickly when the first solenoid valve 9 controls the main valve 5, enabling the main valve 5 to switch to the first working position quickly.

[0068] The output pressure of the second pressure reducing valve 12 can be less than the pressure required for the valve core of the main valve 5 to switch to the second working position. In this way, when the main valve 5 is controlled, the operator can first output an initial pressure to the main valve 5 through the second hand valve 8 to make the valve core of the main valve 5 move a certain distance, so that when the second solenoid valve 10 controls the main valve 5, the valve core of the main valve 5 can respond quickly, so that the main valve 5 can quickly switch to the second working position.

[0069] In an optional embodiment of the present invention, the hydraulic control system may further include a relief valve, which may be connected to the return port of the electrically controlled valve, and the return port of the relief valve may be connected to the oil tank 1 to facilitate oil return.

[0070] In addition, the set pressure of the relief valve can be greater than or equal to the output pressure of the pressure reducing valve. When the pilot oil return pressure of the main valve 5 is less than the output pressure of the pressure reducing valve, the pilot oil return can flow back to the oil tank 1 through the pressure reducing valve and the manual valve; when the pilot oil return pressure of the main valve 5 is greater than or equal to the output pressure of the pressure reducing valve, the pilot oil return can flow back to the oil tank 1 through the solenoid valve and the relief valve. In this way, by cooperating with the pressure reducing valve and the relief valve, constant pressure return of the pilot oil can be achieved.

[0071] It should be noted that when the pilot oil returns through the pressure reducing valve, the pilot oil return can flow back to the hand valve through the gap between the valve core and the valve body of the pressure reducing valve, and then flow back to the oil tank 1 through the return port of the hand valve.

[0072] In an optional embodiment, the overflow valve can include a first overflow valve 13 and a second overflow valve 14.

[0073] The first overflow valve 13 can be connected with the return port of the first electric control valve 9, the return port of the first overflow valve 13 can be connected with the oil tank 1, and the set pressure of the first overflow valve 13 is greater than the output pressure of the first pressure reducing valve 11. In this way, when the pressure of the pilot oil return of the first pilot oil port of the main valve 5 is less than the output pressure of the first pressure reducing valve 11, the pilot oil return of the first pilot oil port can flow back to the oil tank 1 through the first pressure reducing valve 11 and the first hand valve 7; when the pressure of the pilot oil return of the first pilot oil port of the main valve 5 is greater than or equal to the output pressure of the first pressure reducing valve 11, the pilot oil return of the first pilot oil port can flow back to the oil tank 1 through the first electric control valve 9 and the first overflow valve 13.

[0074] The second overflow valve 14 can be connected with the return port of the second electric control valve 10, the return port of the second overflow valve 14 can be connected with the oil tank 1, and the set pressure of the second overflow valve 14 is greater than the output pressure of the second pressure reducing valve 12. In this way, when the pressure of the pilot oil return of the second pilot oil port of the main valve 5 is less than the output pressure of the second pressure reducing valve 12, the pilot oil return of the second pilot oil port can flow back to the oil tank 1 through the second pressure reducing valve 12 and the second hand valve 8; when the pressure of the pilot oil return of the second pilot oil port of the main valve 5 is greater than or equal to the output pressure of the second pressure reducing valve 12, the pilot oil return of the second pilot oil port can flow back to the oil tank 1 through the second electric control valve 10 and the second overflow valve 14.

[0075] In an optional embodiment of the present application, the hydraulic device 6 can be provided with a first working oil port and a second working oil port, and the main valve 5 can be provided with a first oil port and a second oil port, the first oil port can be in communication with the first working oil port, and the second oil port can be in communication with the second working oil port.

[0076] When the valve core of the main valve 5 is in the first working position, the oil inlet of the main valve 5 can be in communication with the first oil port, and the oil return port of the main valve 5 can be in communication with the second oil port, so that the hydraulic oil can flow into the hydraulic device 6 through the first working oil port, and the hydraulic device 6 can perform the first action.

[0077] When the valve core of the main valve 5 is in the second working position, the oil inlet of the main valve 5 can be in communication with the second oil port, and the oil return port of the main valve 5 can be in communication with the first oil port, so that the hydraulic oil can flow into the hydraulic device 6 through the second working oil port, and the hydraulic device 6 can perform the second action.

[0078] In an optional embodiment, the hydraulic control system can further comprise a main pump 3 for providing hydraulic oil for the hydraulic device 6, and an engine 2 for controlling the main pump 3.

[0079] Specifically, the oil inlet of the main pump 3 is communicated with the oil outlet of the oil tank 1, and the oil outlet of the main pump 3 is communicated with the oil inlet of the main valve 5.

[0080] In an optional embodiment, a third overflow valve 17 is further arranged on the pipeline between the oil outlet of the main pump 3 and the oil inlet of the main valve 5, so as to avoid over-high oil supply pressure.

[0081] The working mode of the hydraulic device 6 is as follows:

[0082] The main pump 3 outputs hydraulic oil to the oil inlet of the main valve 5, the hydraulic oil enters the hydraulic device 6 through the first oil port of the main valve 5 and the first working oil port of the hydraulic device 6, so as to realize the first action of the hydraulic device 6; the hydraulic oil in the hydraulic device 6 returns to the oil tank 1 through the second working oil port and the second oil port of the main valve 5 to the oil return port of the main valve 5.

[0083] The main pump 3 outputs hydraulic oil to the oil inlet of the main valve 5, the hydraulic oil enters the hydraulic device 6 through the second oil port of the main valve 5 and the second working oil port of the hydraulic device 6, so as to realize the second action of the hydraulic device 6; the hydraulic oil in the hydraulic device 6 returns to the oil tank 1 through the first working oil port and the first oil port of the main valve 5 to the oil return port of the main valve 5.

[0084] The control mode of the main valve 5 is as follows:

[0085] The process of switching the main valve 5 to the first working position (manual control and electric control are matched) is as follows:

[0086] The hydraulic pilot oil enters the first hand valve 7 from the pilot pump 4, and the operator can dial the first hand valve 7 to output the hydraulic pilot oil, so that the hydraulic pilot oil enters the main valve 5 through the first pressure reducing valve 11 and the first pilot oil port of the main valve 5, and pushes the valve core of the main valve 5 to move a distance (initial distance); at the same time, the first pressure detecting element 15 detects the pressure of the hydraulic pilot oil output by the first hand valve 7, and transmits the detection signal to the controller, and the controller controls the first electric control valve 9 to open and continue to output the hydraulic pilot oil to the first pilot oil port of the main valve 5 according to the detection signal of the first pressure detecting element 15, that is, the hydraulic pilot oil continues to push the valve core of the main valve 5 to move, so that the main valve 5 is switched to the first working position.

[0087] At this time, the pilot oil return of the main valve 5 flows out from the second pilot oil port of the main valve 5, part of which flows back to the oil tank 1 through the second pressure reducing valve 12 and the oil return port of the second hand valve 8; the other part flows back to the oil tank 1 through the second electric control valve 10 and the second overflow valve 14.

[0088] Specifically, when the pressure of the pilot oil return is less than the output pressure of the second pressure reducing valve 12, the pilot oil return flows back to the tank 1 through the second pressure reducing valve 12 and the second hand valve 8; when the pressure of the pilot oil return is greater than or equal to the output pressure of the second pressure reducing valve 12, the pilot oil return flows back to the tank 1 through the second electric control valve 10 and the second overflow valve 14.

[0089] The process of switching the main valve 5 to the second working position (the hand control and electric control cooperation mode) is as follows:

[0090] The hydraulic pilot oil enters the second hand valve 8 from the pilot pump 4, and the operator can dial the second hand valve 8 to output the hydraulic pilot oil, so that the hydraulic pilot oil passes through the second pressure reducing valve 12 and enters the main valve 5 through the second pilot oil port of the main valve 5, and pushes the valve core of the main valve 5 to move a distance (the initial distance). At the same time, the second pressure detecting element 16 detects the pressure of the hydraulic pilot oil output by the second hand valve 8, and transmits the detection signal to the controller. The controller controls the second electric control valve 10 to open and continue to output the hydraulic pilot oil to the second pilot oil port of the main valve 5 according to the detection signal of the second pressure detecting element 16, that is, the hydraulic pilot oil continues to push the valve core of the main valve 5 to move, so that the main valve 5 is switched to the second working position.

[0091] At this time, the pilot oil return of the main valve 5 flows out from the first pilot oil port of the main valve 5, part of which flows back to the tank 1 through the first pressure reducing valve 11 and the return port of the first hand valve 7; the other part flows back to the tank 1 through the first electric control valve 9 and the first overflow valve 13.

[0092] Specifically, when the pressure of the pilot oil return is less than the output pressure of the first pressure reducing valve 11, the pilot oil return flows back to the tank 1 through the first pressure reducing valve 11 and the first hand valve 7; when the pressure of the pilot oil return is greater than or equal to the output pressure of the first pressure reducing valve 11, the pilot oil return flows back to the tank 1 through the first electric control valve 9 and the first overflow valve 13.

[0093] The process of switching the main valve 5 to the first working position (the hand control mode) is as follows:

[0094] The hydraulic pilot oil enters the first hand valve 7 from the pilot pump 4, and the operator dials the first hand valve 7 to output the hydraulic pilot oil, so that the hydraulic pilot oil passes through the first pressure reducing valve 11 and enters the main valve 5 through the first pilot oil port of the main valve 5, and pushes the valve core of the main valve 5 to move to the first working position.

[0095] The process of switching the main valve 5 to the second working position (the hand control mode) is as follows:

[0096] The hydraulic pilot oil enters the second hand valve 8 from the pilot pump 4, and the operator dials the second hand valve 8 to output the hydraulic pilot oil, so that the hydraulic pilot oil passes through the second pressure reducing valve 12 and enters the main valve 5 through the second pilot oil port of the main valve 5, and pushes the valve core of the main valve 5 to move to the second working position.

[0097] It should be noted that in this state, the operator can control the first electric control valve 9 and / or the second electric control valve 10 to remain in the closed state through the input module, so that the hydraulic pilot oil can only pass through the first hand valve 7 or the second hand valve 8.

[0098] For example, the input module can include a control switch, which can be used to control the first electric control valve 9 and / or the second electric control valve 10 to be powered on or powered off. Here, the control switch can be in communication connection with the controller.

[0099] Process of switching the main valve 5 to the first working position (electric control mode):

[0100] The hydraulic pilot oil enters the first electric control valve 9 from the pilot pump 4, and the operator controls the first electric control valve 9 to output the hydraulic pilot oil through the input module, so that the hydraulic pilot oil enters the main valve 5 through the first pilot oil port of the main valve 5, and pushes the spool of the main valve 5 to move to the first working position.

[0101] Process of switching the main valve 5 to the second working position (electric control mode):

[0102] The hydraulic pilot oil enters the second electric control valve 10 from the pilot pump 4, and the operator controls the second electric control valve 10 to output the hydraulic pilot oil through the input module, so that the hydraulic pilot oil enters the main valve 5 through the second pilot oil port of the main valve 5, and pushes the spool of the main valve 5 to move to the second working position.

[0103] In this way, separate hand control, separate electric control, and joint adjustment of hand control and electric control of the main valve 5 can be achieved.

[0104] In an optional embodiment of the present application, the hydraulic device 6 described above can be one of a boom cylinder, a stick cylinder, a bucket cylinder, and a swing motor.

[0105] Specifically, the hydraulic device 6 is a boom cylinder, the first working oil port is in communication with a rodless chamber of the boom cylinder, and the second working oil port is in communication with a rod chamber of the boom cylinder.

[0106] When the spool of the main valve 5 is located at the first working position, hydraulic oil can flow into the rodless chamber of the boom cylinder through the first working oil port, and the hydraulic oil in the rod chamber of the boom cylinder can return to the oil tank 1 through the second working oil port and the return port of the main valve 5. In this way, the extension action of the boom cylinder can be achieved.

[0107] When the spool of the main valve 5 is located at the second working position, hydraulic oil can flow into the rod chamber of the boom cylinder through the second working oil port, and the hydraulic oil in the rodless chamber of the boom cylinder can return to the oil tank 1 through the first working oil port and the return port of the main valve 5. In this way, the contraction action of the boom cylinder can be achieved.

[0108] In this way, the rotation of the boom can be achieved to realize the lifting of the bucket.

[0109] The hydraulic device 6 is a bucket cylinder, the first working oil port is communicated with a rodless chamber of the bucket cylinder, and the second working oil port is communicated with a rod chamber of the bucket cylinder.

[0110] When the spool of the main valve 5 is located at the first working position, hydraulic oil can flow into the rodless chamber of the bucket cylinder through the first working oil port, and the hydraulic oil in the rod chamber of the bucket cylinder can flow back to the oil tank 1 through the second working oil port and the oil return port of the main valve 5. In this way, the elongation action of the bucket cylinder can be realized.

[0111] When the spool of the main valve 5 is located at the second working position, hydraulic oil can flow into the rod chamber of the bucket cylinder through the second working oil port, and the hydraulic oil in the rodless chamber of the bucket cylinder can flow back to the oil tank 1 through the first working oil port and the oil return port of the main valve 5. In this way, the contraction action of the bucket cylinder can be realized.

[0112] In this way, the rotation of the bucket can be realized to realize the forward and backward actions of the bucket.

[0113] The hydraulic device 6 is a bucket cylinder, the first working oil port is communicated with a rodless chamber of the bucket cylinder, and the second working oil port is communicated with a rod chamber of the bucket cylinder.

[0114] When the spool of the main valve 5 is located at the first working position, hydraulic oil can flow into the rodless chamber of the bucket cylinder through the first working oil port, and the hydraulic oil in the rod chamber of the bucket cylinder can flow back to the oil tank 1 through the second working oil port and the oil return port of the main valve 5. In this way, the elongation action of the bucket cylinder can be realized.

[0115] When the spool of the main valve 5 is located at the second working position, hydraulic oil can flow into the rod chamber of the bucket cylinder through the second working oil port, and the hydraulic oil in the rodless chamber of the bucket cylinder can flow back to the oil tank 1 through the first working oil port and the oil return port of the main valve 5. In this way, the contraction action of the bucket cylinder can be realized.

[0116] In this way, the rotation of the bucket can be realized to realize the forward and backward actions of the bucket.

[0117] The hydraulic device 6 can be a rotary motor, and the first working oil port and the second working oil port can be two oil ports of the rotary motor, where the two oil ports refer to an oil inlet and an oil outlet of the rotary motor.

[0118] When the spool of the main valve 5 is located at the first working position, hydraulic oil can flow into the rotary motor through the first working oil port, and flow back to the oil tank 1 through the second working oil port of the rotary motor and the oil return port of the main valve 5. In this way, the forward rotation of the rotary motor can be realized.

[0119] When the spool of the main valve 5 is in the second working position, hydraulic oil can flow into the swing motor through the second working oil port, and return to the oil tank 1 through the first working oil port of the swing motor and the oil return port of the main valve 5. In this way, the reverse rotation of the swing motor can be realized.

[0120] The work machine provided by the present application will be described below, and the work machine described below can be referred to in correspondence with the hydraulic control system described above.

[0121] The work machine provided by the present application can include the hydraulic control system according to any one of the above.

[0122] The work machine provided by the present application achieves the same beneficial effects as the hydraulic control system provided by the present application, and thus will not be described here.

[0123] It should be noted that the work machine described above can be an excavator or other engineering machinery.

[0124] In optional embodiments, the work machine can include four hydraulic devices 6, which are the boom cylinder, the stick cylinder, the bucket cylinder, and the swing motor.

[0125] Among them, the valves in the hydraulic control system can all be four-way valves, for example, the main valve can be a four-way valve to control the four hydraulic devices 6 respectively; the first hand valve and the second hand valve can both be four-way valves, and the first electric control valve and the second electric control valve can both be four-way valves to control the four main valves respectively.

[0126] The device embodiments described above are only schematic, and the units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., they can be located in one place, or distributed on multiple network units. Some or all of the modules can be selected to achieve the purpose of the present embodiment scheme according to actual needs. Those skilled in the art can understand and implement it without creative labor.

[0127] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A hydraulic control system characterized by, Comprise: Hydraulic device for driving the working device of the working machine; Main valve for controlling the hydraulic device; Pilot pump, the oil inlet of the pilot pump is communicated with the oil tank; Hand valve, the oil inlet of the hand valve is communicated with the oil outlet of the pilot pump, and the oil outlet of the hand valve is communicated with the pilot oil inlet of the main valve; Electric control valve, the oil inlet of the electric control valve is communicated with the oil outlet of the pilot pump, and the oil outlet of the electric control valve is communicated with the pilot oil inlet of the main valve; Pressure detection element for detecting the oil outlet pressure of the hand valve; Input module for setting the opening degree of the electric control valve; Controller, which is connected with the electric control valve, the pressure detection element and the input module, controls the opening degree of the electric control valve according to the detection signal of the pressure detection element and / or the input signal of the input module; Further comprising: a pressure reducing valve is arranged between the hand valve and the pilot oil inlet of the main valve, and the output pressure of the pressure reducing valve is less than the pressure when the spool of the main valve switches to the working position.

2. The hydraulic control system of claim 1, wherein, Further comprising: Overflow valve, the overflow valve is connected with the oil return port of the electric control valve, the oil return port of the overflow valve is connected with the oil tank, and the set pressure of the overflow valve is greater than or equal to the output pressure of the pressure reducing valve; Wherein, when the pressure of the pilot oil return of the main valve is less than the output pressure of the pressure reducing valve, the pilot oil return flows back to the oil tank through the pressure reducing valve and the hand valve; When the pressure of the pilot oil return of the main valve is greater than or equal to the output pressure of the pressure reducing valve, the pilot oil return flows back to the oil tank through the electric control valve and the overflow valve.

3. The hydraulic control system of claim 2, wherein, The hand valve comprises a first hand valve and a second hand valve, and the electric control valve comprises a first electric control valve and a second electric control valve, the oil inlets of the first hand valve and the first electric control valve are communicated with the oil outlet of the pilot pump, and the oil outlets of the first hand valve and the first electric control valve are communicated with the first pilot oil inlet of the main valve; the oil outlets of the second hand valve and the second electric control valve are communicated with the second pilot oil inlet of the main valve.

4. The hydraulic control system of claim 3, wherein, The pressure detection element comprises a first pressure detection element and a second pressure detection element, the first pressure detection element is used for detecting the oil outlet pressure of the first hand valve, and the second pressure detection element is used for detecting the oil outlet pressure of the second hand valve; Wherein, the controller controls the opening degree of the first electric control valve according to the detection signal of the first pressure detection element and / or the input signal of the input module; The controller controls the opening degree of the second electric control valve according to the detection signal of the second pressure detection element and / or the input signal of the input module.

5. The hydraulic control system of claim 3, wherein, The pressure reducing valve comprises: A first pressure reducing valve is arranged between the first hand valve and the first pilot oil inlet of the main valve, and the output pressure of the first pressure reducing valve is less than the pressure when the spool of the main valve switches to the first working position; A second pressure reducing valve is arranged between the second hand valve and the second pilot oil inlet of the main valve, and the output pressure of the second pressure reducing valve is less than the pressure when the spool of the main valve switches to the second working position.

6. The hydraulic control system of claim 5, wherein, The overflow valve comprises: A first overflow valve is connected to the oil return port of the first electric control valve, the oil return port of the first overflow valve is connected to the oil tank, and the set pressure of the first overflow valve is greater than the output pressure of the first pressure reducing valve. A second overflow valve is connected to the oil return port of the second electric control valve, the oil return port of the second overflow valve is connected to the oil tank, and the set pressure of the second overflow valve is greater than the output pressure of the second pressure reducing valve.

7. The hydraulic control system of claim 1, wherein, The hydraulic device is one of a boom cylinder, a stick cylinder, a bucket cylinder and a swing motor.

8. The hydraulic control system according to any one of claims 1 to 7, characterized in that, The hydraulic device is provided with a first working oil port and a second working oil port, the main valve is provided with a first oil port and a second oil port, the first oil port is in communication with the first working oil port, the second oil port is in communication with the second working oil port, when the spool of the main valve is in a first working position, the oil inlet of the main valve is in communication with the first oil port, and the oil return port of the main valve is in communication with the second oil port; when the spool of the main valve is in a second working position, the oil inlet of the main valve is in communication with the second oil port, and the oil return port of the main valve is in communication with the first oil port.

9. A work machine characterized by, The hydraulic control system as claimed in any one of claims 1-8.

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