Hydraulic control system and control method for wheeled excavators

Abstract

This invention discloses a hydraulic control system and method for a wheeled excavator, comprising a control module, an accumulator, a power module, a display module, and a detection module. The control module is connected to the excavator's pilot oil source via a control oil circuit. The accumulator is connected to the control module and controls the charging and discharging of hydraulic oil, enabling the recovery of braking energy during excavator braking and the release of braking energy during acceleration. One end of the power module is mechanically connected to the excavator's gearbox, and the other end is connected via a pipeline to the excavator's main control valve, forming a closed loop with the main control valve's output oil circuit. The power module and the control module are connected via a pipeline. The display module is integrated into a display screen in the excavator's cab, used to display the charging pressure of the control module in real time and monitor the charging and discharging process. The detection module is connected to the control module, power module, excavator throttle pedal, and excavator braking equipment, used to detect the magnitude of all pressures.

Description

Technical Field

[0001] This invention relates to the field of excavator technology, and in particular to a hydraulic control system and control method for a wheeled excavator. Background Technology

[0002] Traditional wheeled hydraulic excavators and tracked hydraulic excavators operate on similar principles, both using a diesel engine to drive the main pump and a main valve to control various movements. Due to the complex operating conditions of excavators, the hydraulic system incorporates various control components such as throttle valves and relief valves. Combined with inherent leakage and pressure loss issues in hydraulic systems, this results in a significant reduction in the actual power delivered to the actuators.

[0003] Wheeled excavators are gaining popularity due to their flexibility in relocation and ability to avoid damaging road surfaces. Similar to many mobile machines, they frequently involve acceleration, deceleration, uphill and downhill driving, especially during frequent acceleration and deceleration, where a significant amount of energy is lost as heat during deceleration. Summary of the Invention

[0004] To address some or all of the technical problems existing in the prior art, the present invention provides a hydraulic control system and control method for a wheeled excavator, which can realize the recovery and utilization of braking energy, so that the wheeled excavator can recover some energy when braking and release the recovered energy when accelerating, thereby reducing energy consumption.

[0005] The technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a hydraulic control system for a wheeled excavator, comprising:

[0007] The control module is connected to the excavator's pilot oil source via a control oil circuit;

[0008] An accumulator, connected to the control module, is used to control the charging and discharging process of the hydraulic oil in the accumulator, so that braking energy is recovered when the excavator brakes and braking energy is released when it accelerates again;

[0009] The power module has one end mechanically connected to the excavator's gearbox and the other end connected to the excavator's main control valve via a pipeline, forming a closed loop with the main control valve's output oil circuit. The power module and the control module are connected via a pipeline.

[0010] The display module is integrated into the display screen inside the excavator's cab and is used to display the filling pressure of the control module in real time and monitor the filling and discharging process in real time.

[0011] The detection module is connected to the control module, the power module, the excavator throttle pedal, and the excavator braking equipment. The detection module is used to detect the pressure of the excavator throttle pedal, the gearbox speed, the front and rear axle braking pressure, and the fluid pressure on the control module.

[0012] Furthermore, in the aforementioned hydraulic control system for a wheeled excavator, the control module includes:

[0013] The first proportional valve has its first port connected to the excavator's pilot oil source via a control oil circuit, and its third port connected to the return oil port of the throttle pedal.

[0014] The first directional valve has a first port connected to the second port of the first proportional valve, the second port of the first directional valve is connected to the accumulator via a hydraulic line, and the third port of the first directional valve is connected to one end of the power module via a hydraulic line.

[0015] The second proportional valve has its first port connected to the control oil circuit of the first proportional valve, which is connected to the pilot oil source of the excavator. The third port of the second proportional valve is connected to the return port of the accelerator pedal, which is connected to the third port of the first proportional valve.

[0016] The second directional valve has a first port connected to the second port of the second proportional valve, a second port connected to the hydraulic line of the first directional valve connected to the accumulator, and a third port connected to the other end of the power module.

[0017] A safety valve, one end of which is connected to the second port of the second proportional valve, and the second port of the safety valve is connected to the hydraulic oil circuit of the first directional valve connected to the accumulator.

[0018] Furthermore, in the aforementioned hydraulic control system for a wheeled excavator, the power module includes:

[0019] A travel motor, which is fixedly connected to the gearbox on the excavator;

[0020] The relief valve includes a first relief valve and a second relief valve connected in sequence. The oil inlet of the first relief valve is connected to the third interface of the second directional valve on the control module, and the oil outlet of the second relief valve is connected to the third interface of the first directional valve on the control module.

[0021] A balance valve, the two ends of which are connected to the two ends of the walking motor;

[0022] A first one-way valve is disposed on the pipeline connecting the two ends of the walking motor to the balance valve;

[0023] The second check valve is provided in two parts, which are located on the pipeline between the first relief valve and the second relief valve and the balance valve that are connected in sequence.

[0024] Furthermore, in the aforementioned hydraulic control system for a wheeled excavator, the detection module includes a gearbox speed sensor, which is located between the gearbox and the travel motor.

[0025] Furthermore, in the aforementioned hydraulic control system for a wheeled excavator, the detection module includes a first pressure sensor, which is connected to the second interface of the second directional valve on the control module.

[0026] Furthermore, in the aforementioned hydraulic control system for a wheeled excavator, the detection module includes a second pressure sensor and a third pressure sensor. The second pressure sensor is located on the secondary oil circuit connected to the excavator's throttle pedal, and the third pressure sensor is located on the excavator's brake pedal.

[0027] Furthermore, in the aforementioned hydraulic control system for wheeled excavators, a knob for controlling the filling and discharging of hydraulic oil in the control module and a button for adjusting the filling and discharging mode of the hydraulic oil in the control module are provided below the display screen of the display module.

[0028] Furthermore, in the aforementioned hydraulic control system for wheeled excavators, a reminder device and an alarm device are also provided on the display module for reminding and alarming about the charging and discharging of hydraulic oil in the accumulator.

[0029] Secondly, the present invention also provides a hydraulic control method for a wheeled excavator using the aforementioned hydraulic control system, comprising:

[0030] An energy accumulator is installed on the excavator's control module to recover energy when the excavator brakes and release energy when it accelerates.

[0031] The system acquires the brake pedal pressure and accelerator pedal pressure of the excavator and inputs the acquired pressure into the control module to control the charging and discharging process of the accumulator.

[0032] During the accumulator discharge process, the current of the excavator's main pump and the engine speed are reduced, thereby reducing the engine's power output.

[0033] Furthermore, the aforementioned hydraulic control method for wheeled excavators also includes a knob for controlling the filling and discharging of hydraulic oil in the control module and a button for adjusting the filling and discharging mode of the control module, located below the excavator's display screen.

[0034] The main advantages of the technical solution of this invention are as follows:

[0035] The hydraulic control system for wheeled excavators of this invention enables the recovery and utilization of braking energy. This allows the wheeled excavator to recover some energy during braking and release it during acceleration, thereby reducing energy consumption. Specifically, by adding components such as an accumulator, control valve, and sensors to the wheeled excavator, the system detects the brake pedal pressure and accelerator pedal pressure, and controls the energization and de-energization of the proportional valve to realize the charging and discharging process of the accumulator. Adjusting the discharging speed control knob controls the proportional valve current, thus regulating the accumulator's discharging speed. During the accumulator discharging process, the main pump proportional valve current and engine speed are reduced to decrease engine power output, achieving energy savings. The charging pressure is displayed on the instrument panel, and the charging and discharging process is monitored in real time, ensuring the safety of the accumulator and the safe and stable operation of the entire system. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and constitute a part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0037] Figure 1 This is an overall structural diagram of the hydraulic control system of a wheeled excavator according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the control module in a hydraulic control system for a wheeled excavator according to an embodiment of the present invention;

[0039] Figure 3 This is a schematic diagram of the power module in the hydraulic control system of a wheeled excavator according to an embodiment of the present invention;

[0040] Figure 4 This is a control structure diagram corresponding to working condition two in the hydraulic control method for a wheeled excavator provided in an embodiment of the present invention;

[0041] Figure 5 This is a control structure diagram corresponding to working condition three in the hydraulic control method for a wheeled excavator provided in an embodiment of the present invention;

[0042] Figure 6 This is a schematic flowchart of a hydraulic control method for a wheeled excavator provided in an embodiment of the present invention;

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. Hydraulic oil tank; 2. Engine; 3. Main pump; 4. Main control valve; 5. Throttle pedal pressure sensor; 6. Travel control valve; 7. Throttle pedal; 8. Pilot oil source; 9. Brake oil source; 10. Brake pedal; 11. Front axle brake pressure sensor; 12. Rear axle brake pressure sensor; 13. Central slewing body; 14. Front axle brake; 15. Rear axle brake; 16. Control module; 17. Accumulator; 18. Filling pressure sensor; 19. Power module; 20. Gearbox; 21. Gearbox speed sensor;

[0045] 161. First proportional valve; 162. Second proportional valve; 163. First directional valve; 164. Second directional valve; 165. Safety valve;

[0046] 191. Travel motor; 192. Overflow valve; 193. Second check valve; 194. Balance valve; 195. Oil replenishment valve; 196. First check valve. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0049] As attached Figure 1-6 As shown in the figure, this embodiment of the invention provides a hydraulic control system for a wheeled excavator. The system mainly includes: a control module 16, an accumulator 17, a power module 19, a display module, and a detection module, wherein:

[0050] The control module 16 is connected to the excavator's pilot oil source 8 via a control oil circuit. The accumulator 17 is connected to the control module 16 and is used to control the charging and discharging process of the accumulator 17 under the control of the control module 16, so that braking energy is recovered when the excavator brakes and released when it accelerates again. One end of the power module 19 is mechanically connected to the excavator's gearbox 20, and the other end of the power module 19 is connected to the excavator's main control valve 4 via a pipeline, forming a closed loop with the output oil circuit of the main control valve 4. The power module 19 and the control module 16 are connected via a pipeline. The display module is integrated on the display screen in the excavator's cab and is used to display the charging pressure of the control module 16 in real time and monitor the charging and discharging process in real time. The detection module is connected to the control module 16, the power module 19, the excavator's throttle pedal 7, and the excavator's braking equipment. The detection module is used to detect the magnitude of all pressures, such as the pressure of the excavator's throttle pedal 7, the speed of the gearbox 20, the pressure of the front and rear axle brakes 15, and the magnitude of the charging pressure on the control module 16.

[0051] Therefore, the hydraulic control system for the wheeled excavator of the present invention, by adding components such as an accumulator 17, a control module 16, and sensors to the wheeled excavator, detects the pressure of the brake pedal 10 and the accelerator pedal 7, and controls the on / off state of the proportional valve to realize the charging and discharging process of the accumulator 17; by adjusting the discharging speed control knob, the current of the proportional valve can be controlled to regulate the discharging speed of the accumulator 17; during the discharging process of the accumulator 17, the power output of the engine 2 is reduced by decreasing the current of the proportional valve of the main pump 3 and the speed of the engine 2, thereby achieving energy saving; and by displaying the charging pressure on the instrument and monitoring the charging and discharging process in real time, the safety of the accumulator 17 and the safe and stable operation of the entire system are ensured.

[0052] Specifically, in the hydraulic control system of the wheeled excavator of the present invention, the control module 16 includes: a first proportional valve 161, a first directional valve 163, a second proportional valve 162, a second directional valve 164, and a safety valve 165, wherein:

[0053] The first port of the first proportional valve 161 is connected to the excavator pilot oil source 8 via a control oil circuit, and the third port of the first proportional valve 161 is connected to the return port of the throttle pedal 7. The first port of the first directional valve 163 is connected to the second port of the first proportional valve 161, and the second port of the first directional valve 163 is connected to the accumulator 17 via a hydraulic line. The third port of the first directional valve 163 is connected to one end of the power module 19 via a hydraulic line. The first port of the second proportional valve 162 is connected to the control oil circuit of the first proportional valve 161, which is connected to the excavator pilot oil source 8, and the third port of the second proportional valve 162 is connected to the return port of the throttle pedal 7. The third port of the first proportional valve 161 is connected to the return port of the accelerator pedal for oil return; the first port of the second directional valve 164 is connected to the second port of the second proportional valve 162, the second port of the second directional valve 164 is connected to the hydraulic line of the accumulator 17 connected to the second port of the first directional valve 163, and the third port of the second directional valve 164 is connected to the other end of the power module 19; one end of the safety valve 165 is connected to the second port of the second proportional valve 162, that is, to the return port of the second proportional valve 162, and the second port of the safety valve 165 is connected to the hydraulic line of the accumulator 17 connected to the second port of the first directional valve 163.

[0054] Therefore, the control module 16 can control the charging and discharging of the accumulator 17 according to the different motion states and working conditions of the excavator. By reducing the current of the excavator's main pump proportional valve and the speed of the engine 2, the power output of the engine 2 can be reduced, thereby achieving the purpose of energy saving.

[0055] Specifically, in the hydraulic control system of the wheeled excavator of the present invention, the power module 19 mainly includes: a travel motor 191, an overflow valve 192, a balance valve 194, a replenishing valve 195, and a second check valve 193, wherein:

[0056] The travel motor 191 is fixedly connected to the gearbox 20 on the excavator; the overflow valve 192 includes a first overflow valve and a second overflow valve connected in sequence, the oil inlet of the first overflow valve is connected to the third interface of the second directional valve 164 on the control module 16, and the oil outlet of the second overflow valve is connected to the third interface of the first directional valve 163 on the control module 16; the two ends of the balance valve 194 are connected to the two ends of the travel motor 191; two first check valves 196 are arranged in parallel on the balance valve 194 and connected in sequence, and the first check valves 196 are arranged on the pipeline connecting the two ends of the travel motor 191 to the balance valve 194; the number of second check valves 193 is set to two, and the two second check valves 193 are arranged on the pipeline between the first overflow valve, the second overflow valve and the balance valve 194 connected in sequence.

[0057] Therefore, through the power module 19, combined with the control module 16 mentioned above, the charging and discharging of the accumulator 17 can be adjusted based on the magnitude of the data detected by each detection module and whether the magnitude of the data detected by the detection module reaches the preset rated value range. At the same time, combined with the display module, the energy recovery rate is improved, thereby reducing energy loss.

[0058] Specifically, in the hydraulic control system of the wheeled excavator of the present invention, in addition to the above-mentioned structures and components, it also includes: a hydraulic oil tank 1, a travel control valve 6, a brake oil source 9, a central slewing body 13, a front axle brake 14, and a rear axle brake 15. The connection method of the above-mentioned components is as follows: Figure 1 As shown.

[0059] In this embodiment, in order to further adapt to the operating conditions of the excavator, the control module 16, power module 19, detection unit and display unit of the present invention are connected to the control equipment or control unit on the excavator, for further data detection and energy recovery through feedback adjustment.

[0060] Specifically, in the hydraulic control system of the wheeled excavator of the present invention, the detection module includes a gearbox speed sensor 21, which is disposed between the gearbox 20 and the travel motor 191.

[0061] With this configuration, the speed of the gearbox 20 can be detected by the gearbox speed sensor 21, and the output power of the excavator main pump 3 can be adjusted according to the detected speed, thereby reducing energy consumption and preventing overspeed damage to the transmission system, ensuring the safe and stable operation of the entire system.

[0062] Specifically, in the hydraulic control system of the wheeled excavator of the present invention, the detection module includes a first pressure sensor 18, which is connected to the second interface of the second directional valve 164 on the control module 16 and to the first directional valve 163.

[0063] With this configuration, the pressure inside the accumulator 17 can be detected by the first pressure sensor. Combined with the function of the safety valve 165, the safe and stable operation of the accumulator 17 can be ensured, as well as the safe and stable operation of the entire control system. The pressure of the accumulator 17 is fed back to the controller, and the controller outputs a signal to adjust the current of the proportional valve of the excavator's main pump 3 and the speed of the engine 2, so as to reduce the output power of the engine 2 and achieve the purpose of energy saving.

[0064] In some optional implementations of this embodiment, the first pressure sensor may be a filling pressure sensor 18, used to detect the filling pressure of the accumulator and connected to the control equipment of the excavator.

[0065] Specifically, in the hydraulic control system of the wheeled excavator of the present invention, the detection module includes a second pressure sensor and a third pressure sensor. The second pressure sensor is installed on the secondary oil circuit connected to the excavator throttle pedal 7, and the third pressure sensor is installed on the excavator brake pedal 10.

[0066] With this configuration, the pressure of the excavator throttle pedal 7 and the pressure of the excavator brake pedal 10 can be detected by the second pressure sensor and the third pressure sensor, respectively. By detecting the pressure of the throttle pedal 7 and the brake pedal 10, the proportional valve in the control module 16 can be switched on and off, which can further control the charging and discharging process of the accumulator 17.

[0067] In some optional implementations of this embodiment, the second pressure sensor may be an accelerator pedal pressure sensor 5, and the third pressure sensor may be a front axle brake pressure sensor 11 and a rear axle brake pressure sensor 12, which are used to detect the pressure of the accelerator pedal and the front and rear axle brake pressures, respectively, and are connected to the control equipment of the excavator. The control module provides feedback to adjust the charging and discharging of the accumulator 17, the speed of the engine 2, and the current value of the main pump 3.

[0068] In the hydraulic control system of the wheeled excavator of the present invention, a knob for controlling the charging and discharging of hydraulic oil in the control module 16 and a button for adjusting the charging and discharging mode of the control module 16 are provided below the display screen of the display module. The display module is also equipped with a reminder device and an alarm device for reminding and alarming about the charging and discharging of hydraulic oil in the accumulator 17.

[0069] In some optional implementations of this embodiment, the reminder device is set as an indicator light, displaying different colors according to different working conditions; for example, the indicator light for filling is set to flash red, the indicator light for filling is set to yellow, and the indicator light for filling is set to green, etc., and the corresponding filling process is set to the indicator light flashing, while the completion and completion actions are set to the indicator light remaining constantly on. The alarm device is set as a buzzer, used to alarm for different speeds of hydraulic oil filling and discharging and filling and discharging thresholds. At the same time, in order to better play the alarm and reminder role, the indicator light and the hydraulic oil dispenser can be used in sync.

[0070] Specifically, to better control the filling and discharging of the fluid, making the filling and discharging more precise, while ensuring the safety of the accumulator 17 and the safe and stable operation of the entire control system, and reducing energy loss, a hydraulic hybrid control panel is installed in the excavator cab. This panel includes a filling and discharging combination switch, which can be set to C (fill), F (discharge), OFF (off), and AUTO (automatic) modes. In the C, F, and OFF modes, the user can fill and discharge the fluid as needed, instantly increasing travel power under extreme conditions, such as climbing hills or getting out of trouble. In AUTO mode, the system automatically fills and discharges the fluid based on signals from the brake pedal 10 and accelerator pedal 7. A discharging speed control knob is also provided on the panel for manual control of the discharging speed. A filling indicator light on the panel provides visual reminders to the driver based on its color and flashing.

[0071] Based on actual working conditions and possible working situations, the following explanations are provided regarding the liquid filling indicator light in some optional implementations of this embodiment:

[0072] The filling indicator light is off. The fill / discharge combination switch is in the OFF position. The filling indicator light is solid red. When the filling pressure is low or the filling process is complete, the filling pressure Pc < P1. The filling indicator light is yellow and the volume is constant. Filling fluid, P1 ≤ filling pressure < P2 The filling indicator light flashes red. Filling with liquid The liquid filling indicator light flashes red and is accompanied by a buzzer. Fluid filling failure The filling indicator light is green and the volume is constant. Filling is complete, and the filling pressure Pc ≥ P2 The filling indicator light flashes green. Fluid is being discharged

[0073] Secondly, the present invention also provides a hydraulic control method for a wheeled excavator that applies the above-mentioned hydraulic control system for wheeled excavators, such as... Figure 6 As shown, it includes:

[0074] An accumulator 17 is installed on the control module 16 of the excavator to recover energy when the excavator brakes and release energy when it accelerates. The pressure of the excavator brake pedal 10 and the pressure of the accelerator pedal 7 are acquired and transmitted to the controller. The controller transmits the corresponding pressure signals to the control module 16 to control the charging and discharging process of the accumulator 17. During the discharging process of the accumulator 17, the current of the main pump 3 and the speed of the engine 2 on the excavator are reduced, thereby reducing the power output of the engine 2.

[0075] Specifically, the hydraulic control method for a wheeled excavator of the present invention also includes a knob for controlling the filling and discharging of hydraulic oil in the control module 16 and a button for adjusting the filling and discharging mode of the control module 16, located below the excavator's display screen.

[0076] In some optional implementations of this embodiment, the pressure of the excavator's brake pedal 10 and accelerator pedal 7 can be obtained by detecting pressure sensors.

[0077] Specifically, in the hydraulic control method for wheeled excavators of the present invention, a control knob for adjusting the discharge speed of the accumulator 17 is provided on the control panel of the excavator. By adjusting the discharge speed control knob, the magnitude of the proportional valve current can be controlled to adjust the discharge speed of the accumulator 17.

[0078] Specifically, addressing the problems of low energy utilization efficiency in existing technologies, which result in significant power reduction and energy loss as heat during frequent acceleration and deceleration of traditional wheeled excavators, this application proposes a hydraulic control system and method for wheeled excavators. The principle is as follows: By adding components such as an accumulator 17, a control module 16, and sensors to the wheeled excavator, the pressure of the brake pedal 10 and the accelerator pedal 7 are detected. The proportional valve on the control module 16 is energized and de-energized to realize the charging and discharging process of the accumulator 17. The current of the proportional valve can be controlled by adjusting the discharging speed control knob to regulate the discharging speed of the accumulator 17. During the discharging process of the accumulator 17, the power output of the engine 2 is reduced by decreasing the current of the proportional valve in the main pump 3 and the speed of the engine 2, achieving energy saving. The charging pressure is displayed on the instrument panel, and the charging and discharging process is monitored in real time to ensure the safety of the accumulator 17 and the safe and stable operation of the entire system, thereby reducing energy consumption.

[0079] To make the principle of the hydraulic control system and control method for the wheeled excavator in this application clearer, the following explanations are provided for different working conditions during the actual operation of the excavator, along with their respective logic block diagrams:

[0080] Operating Condition 1: When traveling at a constant speed, neither the first proportional valve 161 nor the second proportional valve 162 is energized, and the energy recovery system does not work.

[0081] Operating Condition 2: First, select the AUTO mode for the filling / discharging fluid combination switch;

[0082] like Figure 1-5 As shown, when the wheeled excavator is moving forward, oil enters through port A and returns through port B. When the accelerator pedal 7 is released and the brake pedal 10 is lightly pressed, the vehicle begins to decelerate when the brake pressure Pz ≥ P3. The controller detects the brake pressure signal, and the brake light illuminates. At this time, under the influence of vehicle inertia, the travel motor 191 is in pump mode, and high pressure appears in MB. When the filling pressure is determined to be < P2, the second proportional valve 162 is energized, the filling red light flashes, and pressurized oil flows from the travel motor 191MB to port A2 of the second reversing valve 164 in the control module 16, starting the filling process. When the filling pressure Pc ≥ P2, the second proportional valve 162 is de-energized, the red light turns green, and the filling stops; or when the brake pedal 10 is released, the filling stops. The specific control flow diagram is shown below. Figure 4As shown; when the wheeled excavator is traveling backwards, oil enters through port B and returns through port A; when the accelerator pedal 7 is released and the brake pedal 10 is lightly pressed, the vehicle begins to decelerate when the brake pressure Pz ≥ P3; the excavator's controller detects the brake pressure signal, and the brake light illuminates; at this time, under the vehicle's inertia, the travel motor 191 is in pump mode, and high pressure appears on MA; when the filling pressure is judged to be < P2, the first proportional valve 161 is energized, the filling red light flashes, and pressurized oil flows from the travel motor 191MA to the filling control valve A1 port, starting the filling process; when the filling pressure Pc ≥ P2, the first proportional valve 161 is de-energized, the red light turns green, and the filling process stops; or when the brake pedal 10 is released, the filling process stops.

[0083] Operating Condition 3: First, select AUTO mode for the filling / discharging combination switch; adjust the discharging speed control knob to the appropriate position;

[0084] When the wheeled excavator starts moving forward, pressing the accelerator pedal 7 triggers the controller to detect that the throttle pressure Py ≥ P4 and the filling pressure Pc ≥ P5. The first proportional valve 161 is energized, the filling green light flashes, and fluid discharge begins. Based on the filling pressure, the excavator's controller actively reduces the current of the main pump 3 proportional valve and the engine speed 2, decreasing the output power of the main pump 3 and reducing energy consumption. When the fluid discharge reaches the filling pressure < P2, the first proportional valve 161 is de-energized, the green light turns red, and fluid discharge stops. Alternatively, releasing the accelerator pedal 7 stops fluid discharge. The specific control flow diagram is shown below. Figure 5 As shown. When the wheeled excavator starts moving backward, pressing the accelerator pedal 7 causes the controller to detect that the throttle pressure Py ≥ P4 and the filling pressure Pc ≥ P5. The second proportional valve 162 is energized, the filling green light flashes, and fluid discharge begins. Based on the filling pressure, the controller actively reduces the current of the main pump 3 proportional valve and the engine speed 2, resulting in a decrease in the output power of the main pump 3 and reduced energy consumption. When the fluid discharge reaches the filling pressure < P2, the second proportional valve 162 is de-energized, the green light turns red, and fluid discharge stops. Alternatively, fluid discharge stops when the accelerator pedal 7 is released.

[0085] Operating Condition 4: When driving downhill, if the excavator gearbox speed sensor 21 detects that N≥n1, the proportional valve for filling should always be de-energized, and the accumulator 17 should be prohibited from releasing fluid to avoid overspeed damage to the transmission system.

[0086] Operating Condition 5: The filling and discharging process can be manually controlled.

[0087] During normal driving, turn the filler / drainage switch to C. The first proportional valve 161 is energized and begins filling. When the filling pressure Pc ≥ P2, the first proportional valve 161 is de-energized, and the filling ends. When driving again, turn the filler / drainage switch to F. The first proportional valve 161 is energized and begins draining. When the filling pressure Pc < P1, the first proportional valve 161 is de-energized, and the draining ends.

[0088] Specifically, in the above operating conditions, P1 represents the minimum pressure of accumulator 17, P2 represents the maximum pressure of accumulator 17, P3 represents the preset pressure of brake pedal, P4 represents the preset pressure of throttle, and P5 is the pressure of accumulator 17 between P1 and P2.

[0089] In one possible implementation of this embodiment, in order to meet the needs of driving in situations requiring quiet operation, the engine 2 can be turned off, and the entire vehicle can be powered on while the fluid draining process is manually initiated for short-distance driving; if the engine 2 is accidentally turned off, short-distance driving can also be achieved in the same way, which can be used as emergency power for the wheeled excavator to move.

[0090] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Additionally, the terms "front," "back," "left," "right," "upper," and "lower" in this document refer to the placement shown in the accompanying drawings.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydraulic control system for a wheeled excavator, comprising: The control module is connected to the excavator's pilot oil source via a control oil circuit; An accumulator, connected to the control module, is used to control the charging and discharging process of the hydraulic oil in the accumulator, so that braking energy is recovered when the excavator brakes and braking energy is released when it accelerates again; The power module has one end mechanically connected to the excavator's gearbox and the other end connected to the excavator's main control valve via a pipeline, forming a closed loop with the main control valve's output oil circuit. The power module and the control module are connected via a pipeline. The display module is integrated into the display screen inside the excavator's cab and is used to display the filling pressure of the control module in real time and monitor the filling and discharging process in real time. The detection module is connected to the control module, the power module, the excavator throttle pedal, and the excavator's braking equipment. The detection module is used to detect the pressure of the excavator throttle pedal, the gearbox speed, the front and rear axle braking pressure, and the fluid pressure on the control module. The control module is characterized by comprising: The first proportional valve has its first port connected to the excavator's pilot oil source via a control oil circuit, and its third port connected to the return oil port of the throttle pedal. The first directional valve has a first port connected to the second port of the first proportional valve, the second port of the first directional valve is connected to the accumulator via a hydraulic line, and the third port of the first directional valve is connected to one end of the power module via a hydraulic line. The second proportional valve has its first port connected to the control oil circuit of the first proportional valve, which is connected to the pilot oil source of the excavator. The third port of the second proportional valve is connected to the return port of the accelerator pedal, which is connected to the third port of the first proportional valve. The second directional valve has a first port connected to the second port of the second proportional valve, a second port connected to the hydraulic line of the first directional valve connected to the accumulator, and a third port connected to the other end of the power module. A safety valve, one end of which is connected to the second port of the second proportional valve, and the second port of the safety valve is connected to the hydraulic oil circuit of the first directional valve connected to the accumulator.

2. The hydraulic control system for a wheeled excavator according to claim 1, characterized in that, The power module includes: A travel motor, which is fixedly connected to the gearbox on the excavator; The relief valve includes a first relief valve and a second relief valve connected in sequence. The oil inlet of the first relief valve is connected to the third interface of the second directional valve on the control module, and the oil outlet of the second relief valve is connected to the third interface of the first directional valve on the control module. A balance valve, the two ends of which are connected to the two ends of the walking motor; A first one-way valve is disposed on the pipeline connecting the two ends of the walking motor to the balance valve; The second check valve is provided in two parts, which are located on the pipeline between the first relief valve and the second relief valve and the balance valve that are connected in sequence.

3. The hydraulic control system for a wheeled excavator according to claim 2, characterized in that, The detection module includes a gearbox speed sensor, which is disposed between the gearbox and the travel motor.

4. The hydraulic control system for a wheeled excavator according to claim 1, characterized in that, The detection module includes a first pressure sensor, which is connected to the second interface of the second directional valve on the control module.

5. The hydraulic control system for a wheeled excavator according to claim 1, characterized in that, The detection module includes a second pressure sensor and a third pressure sensor. The second pressure sensor is installed on the secondary oil circuit connected to the excavator's throttle pedal, and the third pressure sensor is installed on the excavator's brake pedal.

6. The hydraulic control system for a wheeled excavator according to claim 1, characterized in that, Below the display screen of the display module, there is a knob for controlling the filling and discharging of hydraulic oil in the control module and a button for adjusting the filling and discharging mode of the hydraulic oil in the control module.

7. The hydraulic control system for a wheeled excavator according to claim 1, characterized in that, The display module is also equipped with a reminder device and an alarm device, which are used to remind and alarm about the charging and discharging of hydraulic oil in the accumulator.

8. A hydraulic control method for a wheeled excavator using the hydraulic control system of any one of claims 1-7, characterized in that, include: An energy accumulator is installed on the excavator's control module to recover energy when the excavator brakes and release energy when it accelerates. The system acquires the brake pedal pressure and accelerator pedal pressure of the excavator and inputs the acquired pressure into the control module to control the charging and discharging process of the accumulator. During the accumulator discharge process, the current of the excavator's main pump and the engine speed are reduced, thereby reducing the engine's power output.

9. The hydraulic control method for a wheeled excavator according to claim 8, characterized in that, It also includes a knob for controlling the filling and discharging of hydraulic oil in the control module and a button for adjusting the filling and discharging mode of the control module, located below the excavator's display screen.

Images