Composite hydraulic system for integrated drilling and excavation equipment, integrated drilling and excavation equipment

Abstract

The application discloses a composite hydraulic system for a drilling and excavating integrated device and the drilling and excavating integrated device, which insulates a load feedback oil circuit of an excavating arm multi-way valve and a load feedback oil circuit of a drilling arm multi-way valve through a special composite control unit, realizes load sensitive control, and ensures compatible matching of two independent flow compensation systems, namely, drilling arm valve front compensation and excavating arm valve rear compensation, under the same unsaturated pump source. When the highest LS load pressure of each execution chamber in the drilling arm is greater than the highest LS load pressure of each execution chamber in the excavating arm, the oil inlet pressure of the excavating arm multi-way valve is secondarily compensated through the composite control unit, so that the pressure difference between the oil inlet pressure of the excavating arm multi-way valve and the outlet pressure of a valve core throttling port is constant and is not affected by load change, and flow sharing is not affected by execution load pressure change.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drilling and digging integrated equipment, in particular, relates to a composite hydraulic system for drilling and digging integrated equipment, and also relates to a drilling and digging integrated equipment adopting the composite hydraulic system. BACKGROUND

[0002] At present, due to the space limitation of tunnel construction, in order to improve the construction efficiency, a mechanical equipment with multiple functions is usually used for construction operation, wherein the drilling and digging integrated equipment as an integrated equipment capable of simultaneously performing drilling operation and digging operation is widely applied to underground construction scenes. The digging arm and the drilling arm of the drilling and digging integrated equipment both belong to a typical multi-actuator system, and the characteristic thereof is that multiple actuators act simultaneously and the load frequently changes. In order to reduce the system energy consumption and improve the capacity efficiency, the drilling arm and the digging arm usually adopt a load-sensitive system and a variable control system of valve control compensation principle. Among them, since the drilling arm needs to be accurately positioned to realize the accurate control of the eye position, the hydraulic system needs to meet the control requirements of small flow and high precision, and usually the drilling arm adopts the valve-before-compensation principle of the independent compensator configured for each actuation action, so as to ensure the response speed and speed regulation performance of the arm frame operation; and the digging arm operation is usually characterized by large flow, composite and coordinated action, rapid start and the like, and the hydraulic system of the digging arm usually adopts the valve-after-compensation principle with synchronous operation performance of anti-flow unsaturation in a small displacement pump system to realize flow sharing. Since the same work is completed by using as small installed power as possible, the equipment is more compact and precise, the cost performance is higher, and the market is more competitive. Then, the system is very expected to drive the drilling arm and the digging arm by a smaller displacement pump, but the valve-before-compensation flow control system and the valve-after-compensation flow control system are very difficult to match in the variable control system of the same pump source due to the independent load feedback principle, different unloading channels and pressure compensation elements of pump control and valve control, which becomes a technical problem disturbing researchers. SUMMARY

[0003] The present application provides a composite hydraulic system for drilling and digging integrated equipment and drilling and digging integrated equipment, which can ensure efficient shunting of two independent flow control systems under the same pump source, and can prevent the digging arm from suddenly accelerating out of control when the load pressure of the drilling arm is larger.

[0004] According to one aspect of the present application, a composite hydraulic system for a drilling and excavating integrated device is provided, comprising a motor, a load sensing pump, a first shuttle valve, a drilling arm multi-way valve, an excavating arm multi-way valve and a composite control unit, the motor is drivingly connected with the load sensing pump, an oil outlet B of the load sensing pump is connected with an oil inlet P1 of the drilling arm multi-way valve, an oil outlet P2 of the drilling arm multi-way valve is connected with an oil inlet P3 of the composite control unit, an oil outlet P5 of the composite control unit is connected with an oil inlet P6 of the excavating arm multi-way valve, an oil outlet P4 of the composite control unit is connected with an oil inlet P7 of other actuators, an oil return T1 of the composite control unit is connected with an oil return T2 of the drilling arm multi-way valve, an oil return T3 of the drilling arm multi-way valve is connected with an oil return T4 of the excavating arm multi-way valve, an oil return T5 of the excavating arm multi-way valve is connected with an oil tank, one input of the first shuttle valve is connected with a feedback oil port LS1 of other actuators, another input is connected with a feedback oil port LS2 of the drilling arm multi-way valve, and an output is connected with a feedback oil port LS3 of the composite control unit, a feedback oil port LS5 of the composite control unit is connected with a feedback oil port LS4 of the excavating arm multi-way valve, and a feedback oil port LS6 of the composite control unit is connected with a pilot oil port X of the load sensing pump;

[0005] The drilling arm multi-way valve is a pre-compensation multi-way valve for controlling actions of multiple drilling arm actuators and transmitting the highest LS load pressure in each actuating chamber to the first shuttle valve, the excavating arm multi-way valve is a post-compensation multi-way valve for controlling actions of multiple excavating arm actuators and transmitting the highest LS load pressure in each actuating chamber to the composite control unit, the first shuttle valve is used for comparing the highest LS load pressure in each actuating chamber of the drilling arm multi-way valve with the LS load pressure of other actuators, and transmitting the higher one to the composite control unit, the composite control unit is used for screening the highest LS load pressure in the whole system and feeding back to the pilot oil port X of the load sensing pump, and the load sensing pump is used for adaptively adjusting flow according to the highest LS load pressure in the whole system to realize load sensing control.

[0006] The composite control unit is also used for pressure compensation when the highest LS load pressure in each actuating chamber of the drilling arm multi-way valve is greater than the highest LS load pressure in each actuating chamber of the excavating arm multi-way valve, so as to ensure that the pressure difference between the oil inlet pressure of the excavating arm multi-way valve and the outlet pressure of the spool throttle port is constant.

[0007] Furthermore, the composite control unit includes a second shuttle valve and a pressure compensation valve. One input terminal of the second shuttle valve is connected to the output terminal of the first shuttle valve, the other input terminal is connected to the feedback port LS5, and the output terminal is connected to the feedback port LS6. The input terminal of the pressure compensation valve is connected to the inlet port P3, the output terminal is connected to the outlet port P5, the pilot port is connected to the feedback port LS5, and the control port is connected to the output terminal. The pressure difference of the pressure compensation valve is higher than the regulating pressure difference of the load-sensitive pump. When the highest LS load pressure of each actuator chamber in the drill arm multi-way valve is greater than the highest LS load pressure of each actuator chamber in the digging arm multi-way valve, the pressure compensation valve reduces the inlet pressure of the digging arm multi-way valve to the highest LS load pressure of each actuator chamber to ensure that the pressure difference between the inlet pressure of the digging arm multi-way valve and the outlet pressure of the valve core throttle port is constant. When the highest LS load pressure of each actuator chamber in the drill arm multi-way valve is less than the highest LS load pressure of each actuator chamber in the digging arm multi-way valve, the pressure compensation valve is in the normally open state.

[0008] Furthermore, the composite control unit also includes a constant flow control valve, which is used to ensure that the transmitted load pressure changes accordingly when the maximum LS load pressure changes in each actuation chamber of the excavator arm multi-way valve, and to realize the rapid unloading of the load-sensitive pump when the excavator arm actuator stops operating.

[0009] Furthermore, the constant flow control valve includes a flow control valve and a fixed throttle valve. The inlet of the fixed throttle valve is connected to the feedback port LS5, and its outlet is connected to the inlet of the flow control valve. The outlet of the flow control valve is connected to the return port T1, the pilot port is connected to the inlet of the fixed throttle valve, and the control port is connected to the outlet of the fixed throttle valve. The flow control valve adaptively adjusts the throttling area of ​​the valve port according to the inlet and outlet pressures of the fixed throttle valve to keep the pressure difference and flow rate of the fixed throttle valve constant. This ensures that the transmitted load pressure changes with the maximum LS load pressure in each actuator chamber of the excavator arm multi-way valve. When the excavator arm actuator stops operating, the LS load pressure at the pilot port X of the load-sensitive pump is relieved by the constant flow unloading oil circuit composed of the feedback port LS6, the second shuttle valve, the fixed throttle valve, and the flow control valve, which is connected to the return port T1, thereby realizing the rapid unloading of the load-sensitive pump.

[0010] Furthermore, the load-sensitive pump is preset with a minimum displacement to maintain a low flow rate output when the system is in standby mode.

[0011] Furthermore, the composite control unit also includes a three-way flow compensator. The inlet of the three-way flow compensator is connected to the inlet P3, the outlet is connected to the return port T1, the pilot port is connected to the output end of the second shuttle valve, and the control port is connected to its inlet. The spring set pressure difference of the three-way flow compensator is greater than the spring set pressure difference of the variable mechanism of the load-sensitive pump and less than the spring set pressure difference of the pressure compensation valve. When the system is in standby mode, low-pressure overflow is performed through the three-way flow compensator. At the same time, when the required flow of the actuator is lower than the minimum displacement of the load-sensitive pump, the excess flow is overflowed through the three-way flow compensator, and the system pressure is adjusted to maintain a constant system pressure and load-side pressure difference.

[0012] Furthermore, the composite control unit also includes a hydraulic filter disposed between the oil inlet and the feedback oil port LS5 of the fixed throttle valve, used to filter the LS feedback oil circuit of the excavator arm multi-way valve to prevent the throttle port of the fixed throttle valve from becoming blocked.

[0013] Furthermore, the composite control unit also includes a check valve arranged in parallel with the hydraulic filter, used to open the oil passage between the oil inlet of the fixed throttle valve and the feedback oil port LS5 when the hydraulic filter is clogged.

[0014] Furthermore, the composite control unit also includes an overflow valve for limiting the upper limit of the load feedback pressure of each actuation chamber LS of the excavator arm multi-way valve. The oil inlet of the overflow valve is connected to the feedback oil port LS5, and the oil outlet is connected to the return oil port T1.

[0015] In addition, the present invention also provides an integrated drilling and excavation device, which employs the composite hydraulic system described above.

[0016] The present invention has the following beneficial effects:

[0017] The composite hydraulic system for drilling and excavation equipment of the present invention uses a first shuttle valve to select the higher of the highest LS load pressure in each actuator chamber of the drill arm multi-way valve and the LS load pressure of other actuators, and transmits this higher value to the composite control unit. The composite control unit then compares the higher LS load pressure with the highest LS load pressure in each actuator chamber of the excavating arm multi-way valve, selects the maximum LS load pressure in the entire system, and feeds it back to the pilot port of the load-sensitive pump. By isolating the load feedback oil circuits of the excavating arm multi-way valve and the drill arm multi-way valve through the first shuttle valve and the composite control unit, not only is load-sensitive control achieved, but efficient flow splitting of the two independent flow control systems under the same pump source is also ensured. Furthermore, when the highest LS load pressure in each actuator chamber of the drill arm multi-way valve is greater than that in the excavating arm multi-way valve, the composite control unit performs pressure compensation on the inlet pressure of the excavating arm multi-way valve to ensure that the pressure difference between the inlet pressure of the excavating arm multi-way valve and the outlet pressure of the valve core throttle port remains constant, unaffected by load changes, and prevents sudden acceleration and loss of control of the excavating arm.

[0018] In addition, the drilling and excavation integrated equipment of the present invention also has the above-mentioned advantages.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is a schematic diagram of the hydraulic principle of a composite hydraulic system for an integrated drilling and excavation equipment according to a preferred embodiment of this application.

[0022] Explanation of reference numerals in the attached figures

[0023] 1. Motor; 2. Load-sensitive pump; 3. First shuttle valve; 4. Drill arm multi-way valve; 5. Excavator arm multi-way valve; 6. Composite control unit; 100. Drill arm actuator; 200. Excavator arm actuator; 300. Other actuators; 601. Second shuttle valve; 602. Pressure compensation valve; 603. Flow control valve; 604. Fixed throttle valve; 605. Three-way flow compensator; 606. Hydraulic filter; 607. Check valve; 608. Relief valve. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] Reference Figure 1 As shown, a preferred embodiment of this application provides a composite hydraulic system for an integrated drilling and excavation equipment, comprising a motor 1, a load-sensitive pump 2, a first shuttle valve 3, a drill arm multi-way valve 4, an excavating arm multi-way valve 5, and a composite control unit 6. The motor 1 is driven and connected to the load-sensitive pump 2, and the motor 1 provides power for the hydraulic system pump. The oil outlet B of the load-sensitive pump 2 is connected to the oil inlet P1 of the drill arm multi-way valve 4, the oil outlet P2 of the drill arm multi-way valve 4 is connected to the oil inlet P3 of the composite control unit 6, the oil outlet P5 of the composite control unit 6 is connected to the oil inlet P6 of the excavating arm multi-way valve 5, and the oil outlet P4 of the composite control unit 6 is connected to the oil inlet P7 of other actuators 300. The function of the load-sensitive pump 2 is to provide a pressurized oil source for the hydraulic system and adaptively adjust the swashplate angle to change the output flow rate by following the maximum LS load feedback pressure changes in all selected actuators in the system. This maintains the output pressure at the outlet B of the load-sensitive pump 2 at a slightly higher value than the maximum LS feedback pressure received at the pilot port X by a fixed difference, thereby achieving load-sensitive control. The return port T1 of the composite control unit 6 is connected to the return port T2 of the drill arm multi-way valve 4, and the return port T3 of the drill arm multi-way valve 4 is connected to the return port T4 of the excavator arm multi-way valve 5. Return ports T2 and T3 are connected through the internal return oil circuit of the drill arm multi-way valve 4, and the return port T5 of the excavator arm multi-way valve 5 is connected to the oil tank. One input end of the first shuttle valve 3 is connected to the feedback port LS1 of the other actuator 300, the other input end is connected to the feedback port LS2 of the drill arm multi-way valve 4, and the output end is connected to the feedback port LS3 of the composite control unit 6. The feedback port LS5 of the composite control unit 6 is connected to the feedback port LS4 of the excavator arm multi-way valve 5, and the feedback port LS6 of the composite control unit 6 is connected to the pilot port X of the load-sensitive pump 2.

[0026] The drill arm multi-way valve 4 is a pre-valve compensation multi-way valve used to control the operation and reversal of multiple drill arm actuators 100, and to limit the pressure of each action circuit and the main system. It can meet the requirements of low flow and high precision control of drill arm operation. At the same time, it transmits the highest LS load pressure in each actuator chamber to one input end of the first shuttle valve 3, namely the second oil port of the first shuttle valve 3, through its own shuttle valve group. Each link of the pre-valve compensation multi-way valve achieves a constant pressure difference before and after the main valve throttle port through an independent pre-valve compensator, so that the flow rate through the main valve is only proportional to the input signal (operating rod swing angle, etc.) and is independent of load changes. At the same time, when the pre-valve compensation multi-way valve is in the neutral position, it connects the LS feedback pressure of the feedback oil port LS2 to the return oil circuit through the valve core of each link to unload the system. The excavator boom multi-way valve 5 is a post-compensation multi-way valve used to control the movement and reversing of multiple excavator boom actuators 200, and to limit the pressure of each action circuit and the main system. It can meet the control requirements of high flow rate, coordinated action, and rapid start-up of the excavator boom. At the same time, it transmits the highest LS load pressure in each actuator chamber to the composite control unit 6 through its own shuttle valve group. In the post-compensation multi-way valve, the highest LS load pressure in each actuator chamber is transmitted to the compensators after each valve. The pressure is regulated by the load-sensitive pump 2 or the composite control unit 6 to keep the pressure difference before and after the main valve throttle port constant, so that the flow rate through the main valve is only proportional to the input signal (operating lever swing angle, etc.) and is independent of load changes.

[0027] The first shuttle valve 3 compares the highest LS load pressure in each actuation chamber of the drill arm multi-way valve 4 with the LS load pressure of other actuators 300, selecting the one with the higher pressure and transmitting it to the composite control unit 6. The composite control unit 6 selects the highest LS load pressure in the entire system and feeds it back to the pilot port X of the load-sensitive pump 2. The load-sensitive pump 2 adaptively adjusts its flow rate based on the feedback of the highest LS load pressure in the entire system to achieve load-sensitive control. For example, when the highest LS load pressure in each actuation chamber of the drill arm multi-way valve 4 is the highest LS load pressure in the system, the load-sensitive pump 2 adaptively adjusts its flow rate according to the load pressure change of the drill arm actuator 100; when the highest LS load pressure in each actuation chamber of the excavating arm multi-way valve 5 is the highest LS load pressure in the system, the load-sensitive pump 2 adaptively adjusts its flow rate according to the load pressure change of the excavating arm actuator 200. The composite control unit 6 is also used to perform pressure compensation when the highest LS load pressure of each actuating chamber in the drill arm multi-way valve 4 is greater than the highest LS load pressure of each actuating chamber in the digging arm multi-way valve 5, so as to ensure that the pressure difference between the oil inlet pressure of the digging arm multi-way valve 5 and the outlet pressure of the valve core throttle port is constant. It is understandable that when the drill arm and the excavating arm move simultaneously, if the highest LS load pressure of each actuating chamber in the drill arm multi-way valve 4 is greater than the highest LS load pressure of each actuating chamber in the excavating arm multi-way valve 5, the outlet pressure of the load-sensitive pump 2 will adaptively adjust according to the highest load pressure of the drill arm actuator 100. At this time, the inlet of the drill arm multi-way valve 4 has sufficient pressure to drive the load. The drill arm multi-way valve 4 reduces pressure through the compensators before each valve to adapt to its respective load, maintaining a constant pressure difference across the throttle orifice, unaffected by load changes. However, at this time, the main system pressure set according to the highest pressure of the drill arm actuator 100 is higher than the inlet pressure of the excavating arm multi-way valve 5, which is set according to its own highest actuating chamber load pressure. Therefore, the composite control unit 6 performs pressure compensation on the inlet pressure of the excavating arm multi-way valve 5 to ensure that the pressure difference between the inlet pressure of the excavating arm multi-way valve 5 and the outlet pressure of the valve core throttle orifice remains constant, unaffected by load changes. If the highest LS load pressure of each actuator chamber in the drill arm multi-way valve 4 is less than the highest LS load pressure of each actuator chamber in the excavator arm multi-way valve 5, the outlet pressure of the load-sensitive pump 2 will be adaptively adjusted according to the highest load pressure of the excavator arm actuator 200. The composite control unit 6 will not perform pressure compensation. The pressure difference before and after the throttle port of the excavator arm multi-way valve 5 will be adjusted by the load-sensitive pump 2 to achieve load-sensitive control.

[0028] It is understood that the composite hydraulic system for the drilling and excavating integrated equipment in this embodiment uses the first shuttle valve 3 to select the higher of the highest LS load pressure in each actuator chamber of the drill arm multi-way valve 4 and the LS load pressure of other actuators 300, and transmits this higher pressure to the composite control unit 6. The composite control unit 6 then compares the higher LS load pressure with the highest LS load pressure in each actuator chamber of the excavating arm multi-way valve 5, selects the maximum LS load pressure in the entire system, and feeds it back to the pilot port of the load-sensitive pump 2. By isolating the load feedback oil circuit of the excavating arm multi-way valve 5 and the load feedback oil circuit of the drill arm multi-way valve 4 through the first shuttle valve 3 and the composite control unit 6, not only is load-sensitive control achieved, but also efficient flow splitting of the two independent flow control systems under the same pump source is ensured, allowing the drill arm and excavating arm to simultaneously achieve maximum performance. Furthermore, when the highest LS load pressure of each actuating chamber in the drill arm multi-way valve 4 is greater than the highest LS load pressure of each actuating chamber in the excavating arm multi-way valve 5, the composite control unit 6 performs pressure compensation on the inlet pressure of the excavating arm multi-way valve 5 to ensure that the pressure difference between the inlet pressure of the excavating arm multi-way valve 5 and the outlet pressure of the valve core throttle port is constant and unaffected by load changes, thus preventing the excavating arm from suddenly accelerating out of control.

[0029] The composite control unit 6 includes a second shuttle valve 601 and a pressure compensation valve 602. One input end of the second shuttle valve 601 is connected to the output end of the first shuttle valve 3, that is, the first oil port of the second shuttle valve 601 is connected to the feedback oil port LS3, and the third oil port of the first shuttle valve 3 is connected to the feedback oil port LS3; the other input end is connected to the feedback oil port LS5, that is, the second oil port of the second shuttle valve 601 is connected to the feedback oil port LS5; and the output end is connected to the feedback oil port LS6, that is, the third oil port of the second shuttle valve 601 is connected to the feedback oil port LS6, thereby connecting to the pilot oil port X of the load-sensitive pump 2. It is understood that the first shuttle valve 3 selects the higher of the highest LS load pressure in each actuator chamber of the drill arm multi-way valve 4 and the LS load pressure of other actuators 300, and transmits it to the second shuttle valve 601. The second shuttle valve 601 then selects the higher of the higher of the higher and the highest LS load pressure in each actuator chamber of the excavator arm multi-way valve 5, thereby selecting the maximum LS load pressure in the entire system and transmitting it to the pilot port X of the load-sensitive pump 2. The input end of the pressure compensation valve 602 is connected to the inlet port P3, that is, the first port of the pressure compensation valve 602 is connected to the inlet port P3; the output end is connected to the outlet port P5, that is, the second port of the pressure compensation valve 602 is connected to the outlet port P5; the pilot port is connected to the feedback port LS5, that is, the fourth port of the pressure compensation valve 602 is connected to the feedback port LS5; the control port is connected to the output end, that is, the third port of the pressure compensation valve 602 is connected to the second port; and the pressure difference of the pressure compensation valve 602 is higher than the regulating pressure difference of the load-sensitive pump 2. When the highest LS load pressure in each actuator chamber of the drill arm multi-way valve 4 is greater than the highest LS load pressure in each actuator chamber of the digging arm multi-way valve 5, the pressure compensation valve 602 throttles and reduces the output pressure of the load-sensitive pump 2, reducing the inlet pressure of the digging arm multi-way valve 5 to slightly higher than the highest LS load pressure in each actuator chamber. This ensures that the pressure difference between the inlet pressure of the digging arm multi-way valve 5 and the outlet pressure of the valve core throttling port remains constant and is unaffected by load changes, preventing sudden acceleration and loss of control of the digging arm. Conversely, when the highest LS load pressure in each actuator chamber of the drill arm multi-way valve 4 is less than the highest LS load pressure in each actuator chamber of the digging arm multi-way valve 5 (i.e., when the highest LS load pressure in each actuator chamber of the digging arm multi-way valve 5 is the maximum LS load pressure in the entire system), the pressure compensation valve 602 is normally open and does not regulate pressure. The outlet pressure of the load-sensitive pump 2 adaptively adjusts according to the highest load pressure of the digging arm actuator 200, achieving load-sensitive control. Preferably, the pressure compensation valve 602 is a differential pressure reducing valve.

[0030] Optionally, the composite control unit 6 further includes a constant flow control valve, used to ensure that the transmitted load pressure changes accordingly when the maximum LS load pressure changes in each actuation chamber of the excavator arm multi-way valve 5, and to achieve rapid unloading of the load-sensitive pump 2 when the excavator arm actuator 200 stops operating. Preferably, the constant flow control valve includes a flow control valve 603 and a fixed throttle valve 604. The inlet of the fixed throttle valve 604 is connected to the feedback port LS5, and its outlet is connected to the inlet of the flow control valve 603. The outlet of the flow control valve 603 is connected to the return port T1, the pilot port is connected to the inlet of the fixed throttle valve 604, and the control port is connected to the outlet of the fixed throttle valve 604. The flow control valve 603 adaptively adjusts the throttling area of ​​the valve port according to the inlet and outlet pressures of the fixed throttle valve 604, so that the pressure difference and flow rate before and after the fixed throttle valve 604 remain constant. This ensures that the transmitted load pressure changes accordingly when the maximum LS load pressure in each actuator chamber of the excavator arm multi-way valve 5 changes. Furthermore, when the excavator arm actuator 200 stops operating, since the downstream compensation multi-way valve does not have an unloading oil circuit, the LS load pressure at the pilot port X of the load-sensitive pump 2 is relieved by the constant flow unloading oil circuit composed of the feedback port LS6, the second shuttle valve 601, the fixed throttle valve 604, and the flow control valve 603, which is connected to the return port T1. This enables the load-sensitive pump 2 to unload rapidly.

[0031] Optionally, the load-sensitive pump 2 is preset with a minimum displacement to maintain a small flow output when the system is in standby mode, shortening the response time of the main pump loading. This also flushes and preheats the hydraulic system, preventing motion lag caused by oil viscosity and expelling air from the system to avoid component cavitation, thus facilitating rapid response of the boom movement. Preferably, the composite control unit 6 further includes a three-way flow compensator 605. The inlet of the three-way flow compensator 605 is connected to the inlet P3, the outlet is connected to the return port T1, the pilot port is connected to the output end of the second shuttle valve 601, and the control port is connected to its inlet. The spring-set differential pressure of the three-way flow compensator 605 is greater than the spring-set differential pressure of the variable mechanism of the load-sensitive pump 2, but less than the spring-set differential pressure of the pressure compensation valve 602. When the system is in standby mode, i.e., no actuator is activated in the hydraulic system, the pressure compensation valve 602 is fully open. When the output pressure of the load-sensitive pump 2 is greater than the spring set pressure of the three-way flow compensator 605, the valve core of the three-way flow compensator 605 opens, realizing low-pressure overflow return. At the same time, when the required flow of the actuator is lower than the minimum displacement of the load-sensitive pump 2, the excess flow can also be overflowed through the three-way flow compensator 605, thereby regulating the pressure of the main system and keeping the pressure of the main system slightly higher than the load pressure of the highest actuator chamber. This allows the pilot oil source and accumulator of the conventional excavator arm control to be eliminated.

[0032] Optionally, the composite control unit 6 further includes a hydraulic filter 606 disposed between the inlet and feedback port LS5 of the fixed throttle valve 604, for filtering the LS feedback oil path of the excavator arm multi-way valve 5 to prevent blockage of the throttle port of the fixed throttle valve 604. Additionally, the composite control unit 6 includes a check valve 607 disposed in parallel with the hydraulic filter 606, for opening the oil path between the inlet and feedback port LS5 of the fixed throttle valve 604 when the hydraulic filter 606 is blocked.

[0033] Optionally, the composite control unit 6 further includes an overflow valve 608 for limiting the upper limit of the load feedback pressure of each actuation chamber LS of the excavator arm multi-way valve 5. The oil inlet of the overflow valve 608 is connected to the feedback oil port LS5, and the oil outlet is connected to the return oil port T1.

[0034] It can be understood that the working process of the composite hydraulic system of the present invention is as follows:

[0035] When the hydraulic system is in standby mode with no actuators operating, the X port of the load-sensitive pump 2 has no LS feedback pressure. Since the load-sensitive pump 2 is preset to a minimum displacement to maintain a small flow output, there is no outlet for oil in the main system circuit. Therefore, the main system pressure will gradually increase. At the same time, because the pilot port of the three-way flow compensator 605 has no LS feedback pressure, when the main system pressure reaches the spring setting pressure of the three-way flow compensator 605, its valve core opens to overflow and return oil. Furthermore, since the spring setting pressure of the three-way flow compensator 605 is slightly higher than the spring setting pressure of the variable mechanism of the load-sensitive pump 2, the outlet pressure of the load-sensitive pump 2 will be higher than the set pressure difference value of its own variable mechanism. The variable mechanism of the load-sensitive pump 2 aims to reduce the outlet pressure, thereby adaptively driving the swashplate angle of the load-sensitive pump 2 to maintain the minimum displacement. Meanwhile, since the spring setting pressure difference of the pressure compensation valve 602 is slightly higher than the spring setting pressure difference of the three-way flow compensator 605, the oil outlet pressure of the pressure compensation valve 602 is connected to the control oil port. At this time, the pressure cannot push the spring setting, so the pressure compensation valve 602 is in the fully open state, and the main system pressure is transmitted to the oil outlet P5 and the oil inlet P6 for standby. The standby flow of the load-sensitive pump 2 passes through the oil outlet B, then through the oil inlet P1 and oil outlet P2 of the drill arm multi-way valve 4, and through the oil inlet P3 of the composite control unit 6 to the oil inlet of the three-way flow compensator 605. This pushes the valve core of the three-way flow compensator 605 to open and overflow the return oil. The return oil flow passes through the return oil outlet T1 of the composite control unit 6, through the return oil outlets T2 and T3 of the drill arm multi-way valve 4, and then through the return oil outlets T4 and T5 of the excavating arm multi-way valve 5 before flowing back to the oil tank. This completes the flushing and preheating of the main system circuit and components, prevents movement sluggishness caused by oil viscosity, and removes air from the system to avoid component cavitation. When the system has an actuator, the variable response time of the load-sensitive pump 2 is shortened. It can also be used as a pilot control oil source to drive the multi-way valve core to open and the main system pipeline is always full of oil, ensuring the rapid start of each actuator, eliminating action delay, and making the human-machine operation more closely integrated. At the same time, the conventional excavator arm pilot oil source and accumulator can be eliminated.

[0036] When the drill arm actuator 100 operates independently, the valve cores of each valve in the drill arm multi-way valve 4 open, transmitting the highest load pressure of each actuator chamber to the feedback port LS2 through its own shuttle valve network. At this time, the second and third ports of the first shuttle valve 3 are connected, thereby transmitting the pressure to the feedback port LS3 of the composite control unit 6. The first and third ports of the second shuttle valve 601 are connected, thereby transmitting the pressure to the pilot port X of the load-sensitive pump 2 to load the pilot ports of the load-sensitive pump 2 and the three-way flow compensator 605. Since the second shuttle valve 601 isolates the LS feedback oil circuit of the drill arm actuator 100 from the quantitative unloading oil circuit composed of the flow control valve 603 and the fixed throttle valve 604, the feedback pressure is unaffected. At this point, if the required flow rate of the drill arm actuator 100 is lower than the minimum displacement of the load-sensitive pump 2, the drill arm actuator 100 cannot absorb all the flow rate of the load-sensitive pump 2 to the load end, and the pressure at the outlet B of the load-sensitive pump 2 will continue to rise. At this time, the variable mechanism of the load-sensitive pump 2 aims to reduce the pressure at the main pump outlet B, while adaptively pushing the swashplate angle of the load-sensitive pump 2 to maintain the minimum displacement. When the pressure at the outlet B of the load-sensitive pump 2 reaches the differential pressure setting value of the three-way flow compensator 605, the valve core of the three-way flow compensator 605 overflows, and the main system pressure is regulated by the three-way flow compensator 605 to ensure sufficient pressure at the inlet of the drill arm multi-way valve 4 to drive the load. The drill arm multi-way valve 4 then uses compensators before each valve to compensate for pressure to adapt to its respective load, maintaining a constant differential pressure across the throttle port unaffected by load changes. The flow capacity of the three-way flow compensator 605 does not need to be large; it only needs to meet the minimum displacement flow requirement of the load-sensitive pump 2. If the required flow rate of the drill arm actuator 100 is higher than the minimum displacement of the load-sensitive pump 2, the drill arm actuator 100 can absorb all the minimum flow rate of the load-sensitive pump 2 to the load end. Therefore, when the load changes, the load-sensitive pump 2 can reduce the pressure at the outlet B by adjusting the displacement. There is no excess flow to cause a pressure rise and open the three-way flow compensator 605. At this time, the main system pressure is regulated by the variable mechanism of the load-sensitive pump 2, ensuring that there is sufficient pressure at the inlet of the drill arm multi-way valve 4 to drive the load. When the drill arm actuator 100 changes from the moving state to the stopped state, the drill arm multi-way valve 4 returns to the neutral position under the action of each set of reset springs. The LS load pressure of the pilot port X of the load-sensitive pump 2 is connected to the feedback port LS6 of the composite control unit 6 and the second shuttle valve 601 to the feedback port LS3 of the composite control unit 6, and then connected to the shuttle valve group of the drill arm multi-way valve 4 by the first shuttle valve 3. Finally, it is depressurized by connecting to the return oil through the main valve core oil passage, thereby realizing the rapid unloading of the load-sensitive pump 2.

[0037] When the excavator arm actuator 200 operates independently, the valve cores of each link of the excavator arm multi-way valve 5 open, and the highest LS load pressure of each actuator chamber is connected through the internal oil passage. At the same time, it is transmitted to the compensation valve after each link valve, and then transmitted to the feedback oil port LS5 of the composite control unit 6 through the feedback oil port LS4. Here, the overflow valve 608 limits the safety pressure of this LS feedback oil circuit. At the same time, the hydraulic filter 606 is connected in parallel, so that the LS feedback oil circuit is connected to the constant flow unloading oil circuit composed of the flow control valve 603 and the fixed throttle valve 604. At the same time, a check valve 607 is connected in parallel with the hydraulic filter 606. When the pressure loss of the hydraulic filter 606 increases to the spring adjustment pressure of the check valve 607 (i.e., when the hydraulic filter 606 is blocked), the check valve 607 opens to connect the oil circuit. Simultaneously, the feedback port LS5 of the composite control unit 6 is also connected to the second port of the second shuttle valve 601. At this time, the second and third ports of the second shuttle valve 601 are connected and transmit the signal to the pilot port X of the load-sensitive pump 2, loading the load-sensitive pump 2, and simultaneously transmitting the signal to the pilot port of the three-way flow compensator 605. Since the spring setting pressure difference of the pressure compensation valve 602 is slightly higher than the spring setting pressure difference of the three-way flow compensator 605, the outlet of the pressure compensation valve 602 is led to the control port. The pressure here cannot push the spring setting, so the pressure compensation valve 602 is in the fully open state. If the required flow rate of the excavator arm actuator 200 is lower than the minimum displacement of the load-sensitive pump 2, the excavator arm actuator 200 cannot absorb all the flow rate of the load-sensitive pump 2 to the load end. The pressure at the oil outlet B of the load-sensitive pump 2 will continue to rise. At this time, the variable mechanism of the load-sensitive pump 2 expects to reduce the pressure at the main pump outlet B and adaptively pushes the swashplate angle of the load-sensitive pump 2 to maintain the minimum displacement. At the same time, the pressure at the oil outlet B of the load-sensitive pump 2 will reach the differential pressure setting value of the three-way flow compensator 605. At this time, the three-way flow compensator 605 overflows and the system pressure is regulated by the three-way flow compensator 605 to ensure that there is sufficient pressure at the oil inlet of the excavator arm multi-way valve 5 to drive the load. The excavator arm multi-way valve 5 internally performs pressure compensation through the downstream compensating valves of each valve to adapt to their respective loads. The three-way flow compensator 605 and the downstream compensator work together to maintain a constant differential pressure across the throttle port, unaffected by load changes. If the required flow rate of the excavator arm actuator 200 is higher than the minimum displacement of the load-sensitive pump 2, the excavator arm actuator 200 can absorb all the minimum flow rate of the load-sensitive pump 2 to the load end. When the load changes, the load-sensitive pump 2 can reduce the pressure at the oil outlet B by adjusting the displacement. There is no excess flow to cause pressure rise and open the three-way flow compensator 605. At this time, the system pressure is regulated by the load-sensitive pump 2 to ensure that there is sufficient pressure at the oil inlet of the excavator arm multi-way valve 5 to drive the load.When the excavator arm actuator 200 changes from the moving state to the stopped state, the excavator arm multi-way valve 5 returns to the neutral position under the action of each set of reset springs. The LS load pressure of the pilot oil port X of the load-sensitive pump 2 is relieved by the feedback oil port LS6 of the composite control unit 6, the second shuttle valve 601, the hydraulic filter 606, and then through the quantitative unloading oil circuit composed of the flow control valve 603 and the fixed throttle valve 604, which is connected to the return oil, so that the load-sensitive pump 2 is quickly unloaded.

[0038] When the drill arm actuator 100 and the digging arm actuator 200 operate simultaneously, the load feedback oil circuits of the drill arm multi-way valve 4 and the digging arm multi-way valve 5 are respectively transmitted to the second shuttle valve 601, and the higher pressure path is selected to feed back to the pilot port X of the load-sensitive pump 2. When the highest LS load pressure in each actuator chamber of the digging arm multi-way valve 5 is higher than the highest LS load pressure in each actuator chamber of the drill arm multi-way valve 4, the system operation process is similar to the process of the digging arm actuator 200 operating alone. The outlet pressure of the load-sensitive pump 2 is adjusted according to the highest LS load pressure in each actuator chamber of the digging arm multi-way valve 5. At this time, the inlet of the drill arm multi-way valve 4 has sufficient pressure to drive the load. The internal pressure of the drill arm multi-way valve 4 is reduced through the compensators before each valve to adapt to its respective load, maintaining a constant pressure difference across the throttle port and unaffected by load changes. The boom multi-way valve 5 also reduces pressure through compensators after each valve to adapt to its respective load. The load-sensitive pump 2 or the three-way flow compensator 605 works together with the compensators after the valve to maintain a constant pressure difference across the throttle orifice, unaffected by load changes. When the highest LS load pressure in each actuating chamber of the boom multi-way valve 5 is lower than the highest LS load pressure in each actuating chamber of the boom multi-way valve 4, the outlet pressure of the load-sensitive pump 2 is adjusted according to the highest LS load pressure in each actuating chamber of the boom multi-way valve 4. At this time, the inlet of the boom multi-way valve 4 has sufficient pressure to drive the load. The boom multi-way valve 4 reduces pressure through compensators before each valve to adapt to its respective load, maintaining a constant pressure difference across the throttle orifice, unaffected by load changes. However, the main system pressure set according to the highest LS load pressure of each actuating chamber of the boom multi-way valve 4 is higher than the inlet pressure required for the compensation pressure set by the boom multi-way valve 5 based on its own highest actuating chamber load pressure. Therefore, pressure compensation is required through the pressure compensation valve 602. The maximum load feedback pressure transmitted from the excavator boom multi-way valve 5 is transmitted to the feedback port LS5 of the composite control unit 6 via the feedback port LS4, and acts on the pilot port of the pressure compensation valve 602. The control port of the pressure compensation valve 602 introduces the pressure at the outlet and adjusts the throttle area to set the pressure at the outlet to be slightly higher than the pilot port pressure by a spring pressure set value, thereby reducing the inlet pressure of the excavator boom multi-way valve 5. The excavator boom multi-way valve 5 then reduces the pressure through the compensators after each valve to adapt to its respective load, so that the pressure compensation valve 602 and the compensators after the valve work together to maintain a constant pressure difference before and after the throttle port, unaffected by load changes.

[0039] In addition, another embodiment of the present invention provides an integrated drilling and excavation device, preferably employing the composite hydraulic system described above.

[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite hydraulic system for integrated drilling and excavation equipment, characterized in that, The system includes a motor (1), a load-sensitive pump (2), a first shuttle valve (3), a drill arm multi-way valve (4), an excavating arm multi-way valve (5), and a composite control unit (6). The motor (1) is driven by the load-sensitive pump (2). The outlet B of the load-sensitive pump (2) is connected to the inlet P1 of the drill arm multi-way valve (4). The outlet P2 of the drill arm multi-way valve (4) is connected to the inlet P3 of the composite control unit (6). The outlet P5 of the composite control unit (6) is connected to the inlet P6 of the excavating arm multi-way valve (5). The outlet P4 of the composite control unit (6) is connected to the inlet P7 of other actuators (300). The return port T1 of the composite control unit (6) is connected to the drill arm multi-way valve (5). The return port T2 of the arm multi-way valve (4) is connected, the return port T3 of the drill arm multi-way valve (4) is connected to the return port T4 of the excavating arm multi-way valve (5), the return port T5 of the excavating arm multi-way valve (5) is connected to the oil tank, one input end of the first shuttle valve (3) is connected to the feedback port LS1 of other actuators (300), the other input end is connected to the feedback port LS2 of the drill arm multi-way valve (4), the output end is connected to the feedback port LS3 of the composite control unit (6), the feedback port LS5 of the composite control unit (6) is connected to the feedback port LS4 of the excavating arm multi-way valve (5), and the feedback port LS6 of the composite control unit (6) is connected to the pilot port X of the load sensitive pump (2). The drill arm multi-way valve (4) is a pre-valve compensation multi-way valve, used to control the operation of multiple drill arm actuators (100) and transmit the highest LS load pressure in each actuator chamber to the first shuttle valve (3). The digging arm multi-way valve (5) is a post-valve compensation multi-way valve, used to control the operation of multiple digging arm actuators (200) and transmit the highest LS load pressure in each actuator chamber to the composite control unit (6). The first shuttle valve (3) is used to compare the highest LS load pressure in each actuator chamber of the drill arm multi-way valve (4) with the LS load pressure of other actuators (300), and select the one with higher pressure to transmit to the composite control unit (6). The composite control unit (6) is used to select the highest LS load pressure in the entire system and feed back to the pilot port X of the load-sensitive pump (2). The load-sensitive pump (2) is used to adaptively adjust the flow rate according to the feedback of the highest LS load pressure in the entire system to achieve load-sensitive control. The composite control unit (6) is also used to perform pressure compensation when the highest LS load pressure of each execution chamber in the drill arm multi-way valve (4) is greater than the highest LS load pressure of each execution chamber in the digging arm multi-way valve (5), so as to ensure that the pressure difference between the oil inlet pressure of the digging arm multi-way valve (5) and the outlet pressure of the valve core throttle port is constant. The composite control unit (6) includes a second shuttle valve (601) and a pressure compensation valve (602). One input end of the second shuttle valve (601) is connected to the output end of the first shuttle valve (3), the other input end is connected to the feedback port LS5, and the output end is connected to the feedback port LS6. The input end of the pressure compensation valve (602) is connected to the inlet port P3, the output end is connected to the outlet port P5, the pilot port is connected to the feedback port LS5, and the control port is connected to the output end. The pilot port and the control port of the pressure compensation valve (602) are on opposite sides of the pressure compensation valve (602), and the pressure difference of the pressure compensation valve (602) is higher than the regulating pressure difference of the load-sensitive pump (2). When the drill arm multi-way valve When the highest LS load pressure in each of the actuators in (4) is greater than the highest LS load pressure in each of the actuators in the boom multi-way valve (5), the pressure compensation valve (602) reduces the inlet pressure of the boom multi-way valve (5) to the highest LS load pressure in each of its actuators, so as to ensure that the pressure difference between the inlet pressure of the boom multi-way valve (5) and the outlet pressure of the valve core throttle port is constant. When the highest LS load pressure in each of the actuators in the boom multi-way valve (4) is less than the highest LS load pressure in each of the actuators in the boom multi-way valve (5), the pressure compensation valve (602) is in the normally open state. The composite control unit (6) also includes a constant flow control valve (603) to ensure the transmission when the maximum LS load pressure in each actuator of the boom multi-way valve (5) changes. The load pressure changes dynamically, and the load-sensitive pump (2) is rapidly unloaded when the excavator arm actuator (200) stops operating. The constant flow control valve (603) includes a flow control valve (603) and a fixed throttle valve (604). The inlet of the fixed throttle valve (604) is connected to the feedback port LS5, and the outlet of the fixed throttle valve (604) is connected to the inlet of the flow control valve (603). The outlet of the flow control valve (603) is connected to the return port T1, the pilot port is connected to the inlet of the fixed throttle valve (604), and the control port is connected to the outlet of the fixed throttle valve (604). The pilot port of the flow control valve (603) and the control port of the flow control valve (603) are connected at the flow rate. On both sides of the control valve (603), the flow control valve (603) adaptively adjusts the throttling area of ​​the valve port according to the inlet pressure and outlet pressure of the fixed throttling valve (604) so ​​that the pressure difference before and after the fixed throttling valve (604) is constant and the flow rate is constant. Thus, when the maximum LS load pressure in each execution chamber of the excavator arm multi-way valve (5) changes, the transmitted load pressure is guaranteed to change accordingly. When the excavator arm actuator (200) stops operating, the LS load pressure of the pilot oil port X of the load sensitive pump (2) is connected to the return oil port T1 by the constant flow unloading oil circuit composed of the feedback oil port LS6, the second shuttle valve (601), the fixed throttling valve (604) and the flow control valve (603) to relieve pressure, thereby realizing the rapid unloading of the load sensitive pump (2).

2. The composite hydraulic system for integrated drilling and excavation equipment as described in claim 1, characterized in that, The load-sensitive pump (2) is preset with a minimum displacement to maintain a small flow rate output when the system is in standby mode.

3. The composite hydraulic system for integrated drilling and excavation equipment as described in claim 2, characterized in that, The composite control unit (6) further includes a three-way flow compensator (605). The inlet of the three-way flow compensator (605) is connected to the inlet P3, the outlet is connected to the return port T1, the pilot port is connected to the output end of the second shuttle valve (601), and the control port is connected to the inlet of the three-way flow compensator (605). The pilot port and the control port of the three-way flow compensator (605) are located on both sides of the three-way flow compensator (605). The spring set pressure difference of the flow compensator (605) is greater than the spring set pressure difference of the variable mechanism of the load sensitive pump (2) and less than the spring set pressure difference of the pressure compensation valve (602). When the system is in standby mode, low-pressure overflow is performed through the three-way flow compensator (605). At the same time, when the required flow of the actuator is lower than the minimum displacement of the load sensitive pump (2), the excess flow is overflowed through the three-way flow compensator (605), and the system pressure is adjusted to maintain the system pressure and the load end pressure difference constant.

4. The composite hydraulic system for integrated drilling and excavation equipment as described in claim 3, characterized in that, The composite control unit (6) also includes a hydraulic filter (606) disposed between the oil inlet and the feedback oil port LS5 of the fixed throttle valve (604) for filtering the LS feedback oil circuit of the excavator arm multi-way valve (5) to prevent the throttle port of the fixed throttle valve (604) from being blocked.

5. The composite hydraulic system for integrated drilling and excavation equipment as described in claim 4, characterized in that, The composite control unit (6) also includes a one-way valve (607) arranged in parallel with the hydraulic filter (606) for opening the oil passage between the inlet of the fixed throttle valve (604) and the feedback oil port LS5 when the hydraulic filter (606) is blocked.

6. The composite hydraulic system for integrated drilling and excavation equipment as described in claim 5, characterized in that, The composite control unit (6) also includes an overflow valve (608) for limiting the upper limit of the load feedback pressure of each actuation chamber LS of the excavator arm multi-way valve (5). The oil inlet of the overflow valve (608) is connected to the feedback oil port LS5, and the oil outlet is connected to the return oil port T1.

7. A drilling and excavation integrated device, characterized in that, The composite hydraulic system described in any one of claims 1 to 6 is adopted.

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