A multi-modal adaptive hydraulic control system and method for a paving machine screed

Abstract

This invention relates to the field of road construction machinery technology, specifically to a hydraulic control system and method for a screed used in a paver. The invention achieves multiple working modes by adjusting the control logic combinations of control valve blocks, pilot valves, lifting valves, speed control valves, synchronization valves, loop valves, load reduction pressure switch valves, left floating valves, right floating valves, right locking valves, and left locking valves to adapt to the performance requirements of various working stages during the paving process. This invention can automatically identify the stage and working condition of the paving operation, controlling each control valve to execute the corresponding control logic, enabling the hydraulic system to adaptively switch between multiple working modes, including pre-adjustment and synchronization mode, paving floating mode, active locking mode, and adaptive pressure adjustment mode. This invention achieves high-precision synchronization of screed pre-leveling, effectively solving construction problems such as difficulty in leveling ultra-wide screeds, asymmetrical paving indentations, and low-temperature start-up bulges, significantly improving paving quality and intelligence.

Description

Technical Field

[0001] This invention relates to the field of road construction machinery technology, specifically to a hydraulic control system and control method for a screed used in a paver. Background Technology

[0002] Pavers are indispensable construction equipment in high-grade highway construction, mainly used for paving base stabilization materials and surface asphalt mixtures. The screed, its core component, plays a crucial role in the paving quality. Currently, common pavers consist of a main unit, a screed, and a boom. The screed is hinged to the leveling cylinders at the front of the main unit via the left and right booms, which are also connected to the rear of the main unit via lifting cylinders. During paving, the screed maintains balance under the influence of its own weight, the support force of the mixture, the resistance of the material pile, the friction of the bottom surface, and the hinge points of the boom.

[0003] Traditional screed hydraulic control systems for pavers mainly perform basic lifting, lowering, and simple floating functions. However, the performance requirements for the screed hydraulic control system vary depending on the working conditions at different stages of the paving process. Existing screed hydraulic control systems have limited adaptability to different working conditions and cannot independently meet the quality control needs of various working conditions in complex paving scenarios. Summary of the Invention

[0004] To address the above shortcomings, this invention provides a multi-modal adaptive hydraulic control system and method for a paver screed. By adjusting the control logic combination states of the pilot valve, lifting valve, speed regulating valve, synchronization valve, circuit valve, load reduction pressure switch valve, control valve block, left floating valve, right floating valve, right locking valve, and left locking valve, multiple working modes can be achieved to adapt to the performance requirements of various working conditions during the paving process.

[0005] In a first aspect, the present invention provides a multimodal adaptive hydraulic control system for a paver screed, comprising: Left and right hydraulic cylinders are used to connect the left and right paving sections of the screed, respectively. The control valve block has its P port connected in series with the flow valve and connected to the Pa and Pb ports of the flow valve. The Pb port of the flow valve is connected to the P2 port of the lift valve via a pilot valve. The pilot valve is used to control the oil circuit connection between the Pb port of the flow valve and the P2 port of the lift valve. The P2 port of the lift valve is connected to either the A2 or B2 port of the lift valve. The A2 port of the lifting valve is connected in parallel to the rodless chambers of the left and right hydraulic cylinders via a loading pressure valve; the oil inlet of the rodless chambers of the left and right hydraulic cylinders is provided with a left locking valve and a right locking valve, respectively. The B2 port of the lifting valve is connected to the first port of the synchronous flow divider and combiner valve via the speed control valve; the first port of the synchronous flow divider and combiner valve is connected to the T port of the control valve block via the loop valve. The first port of the synchronous flow divider and combiner valve is connected in parallel with the second and third ports through a synchronous valve; the second port of the synchronous flow divider and combiner valve is connected to the rod chamber of the left hydraulic cylinder through a left floating valve; the third port of the synchronous flow divider and combiner valve is connected to the second port of the load reduction pressure switching valve, and the first port of the load reduction pressure switching valve is connected to the rod chamber of the right hydraulic cylinder through a right floating valve. The first port of the unloading pressure switching valve is connected to the second or third port; The Pa port of the flow valve is connected in parallel to the inlet of the first and second load relief pressure valves via the load relief pressure switching valve. The outlet of the first load relief pressure valve is connected to the first port of the synchronous flow divider and combiner valve. The outlet of the second load relief pressure valve is connected to the third port of the load relief pressure switching valve.

[0006] Optionally, the pilot valve's P1 port is connected to the flow valve's Pb port and is located upstream of the lift valve's P2 port. The pilot valve's A1 port and T1 port are both connected to the control valve block's T port, and its B1 port is connected to the flow valve's Pb port and is located downstream of the pilot valve's P1 port and upstream of the lift valve's P2 port. When the pilot valve's electrical interface Y1 is not energized, the pilot valve is in the lower position, the pilot valve's P1 port and A1 port are connected, the pilot valve's T1 port and B1 port are connected, the flow valve's Pb port is connected to the control valve block's T port, and the lift valve's A2 port does not receive oil. When the electrical interface Y1 of the pilot valve is energized, the pilot valve is in the upper position, the P1 port and B1 port of the pilot valve are connected, the T1 port and A1 port are connected, and the Pb port of the flow valve is connected to the A2 port of the lift valve through the pilot valve.

[0007] Optionally, when neither electrical interface Y2 nor electrical interface Y3 connected to the lifting valve is energized, the lifting valve is in the neutral position, both P2 and B2 ports of the lifting valve are closed, A2 and T2 ports of the lifting valve are connected, and T2 port of the lifting valve is connected to the T port of the control valve block. When the electrical interface Y2 connected to the lifting valve is energized, the lifting valve is in the upper position, and the P2 port and B2 port of the lifting valve are connected, and the A2 port and T2 port are connected. When the electrical interface Y3 connected to the lifting valve is energized, the lifting valve is in the lower position, and the P2 port and A2 port of the lifting valve are connected, and the B2 port and T2 port are connected.

[0008] Optionally, the upper oil port of the speed regulating valve is connected to the B2 port of the lifting valve; the lower oil port of the speed regulating valve is connected to the first port of the synchronous flow divider and combiner valve. The speed regulating valve has a parallel forward oil passage and a reverse speed regulating oil passage between its upper and lower oil ports. The upper oil port of the speed control valve is unidirectionally connected to the lower oil port via a one-way valve on the forward oil circuit. The lower oil port of the speed control valve is connected to the upper oil port through an electro-proportional throttling orifice.

[0009] Optionally, it also includes: The synchronizing valve has its P3 and T3 ports connected to the first port of the synchronizing flow divider and combiner valve, and its A3 and B3 ports connected to the second and third ports of the synchronizing flow divider and combiner valve, respectively. When the electrical interface Y4 of the synchronizing valve is not energized, the P3 port and A3 port of the synchronizing valve are connected, and the T3 port and B3 port of the synchronizing valve are connected. When the electrical interface Y4 of the synchronizing valve is energized, ports P3, A3, T3, and B3 of the synchronizing valve are all shut off.

[0010] Optionally, the P4 port and T4 port of the loop valve are both connected to the T port of the control valve block, and the A4 port of the loop valve is connected to the second port of the loading pressure valve. The first port of the loading pressure valve is connected to the A2 port of the lifting valve, and the second port of the loading pressure valve is connected in parallel to the rodless chambers of the left and right hydraulic cylinders. By controlling the electrical interface Y7 connected to the loading pressure valve, the valve core opening of the loading pressure valve can be controlled to control the rodless chamber pressure of the left and right hydraulic cylinders.

[0011] Optionally, the P5 port of the unloading pressure switching valve is connected to the Pa port of the flow valve, the A5 port is connected in parallel to the oil inlet of unloading pressure valve one and unloading pressure valve two, the B5 port is connected to the T port of the control valve block, and the T5 port is connected to the T port of the control valve block. When the electrical interface Y6 connected to the load reduction pressure switch valve is not energized, the P5 port and B5 port of the load reduction pressure switch valve are connected, and the T5 port and A5 port of the load reduction pressure switch valve are connected. When the electrical interface Y6 connected to the load reduction pressure switch valve is energized, the P5 port and A5 port of the load reduction pressure switch valve are connected, and the T5 port and B5 port of the load reduction pressure switch valve are connected. By controlling the electrical interface Y9 connected to the unloading pressure valve, the valve core opening of the unloading pressure valve can be controlled to control the rod chamber pressure of the left hydraulic cylinder. By controlling the electrical interface Y10 connected to the second load relief pressure valve, the valve core opening of the second load relief pressure valve can be controlled to control the rod chamber pressure of the right hydraulic cylinder.

[0012] Optionally, When the electrical interface Y13 connected to the left locking valve is not energized, the left locking valve is bidirectionally open, and the rodless chamber of the left hydraulic cylinder can receive or return oil. When the electrical interface Y13 connected to the left locking valve is energized, the left locking valve is unidirectionally open, and the rodless chamber of the left hydraulic cylinder can only receive oil. When the electrical interface Y11 connected to the right locking valve is not energized, the right locking valve is bidirectionally open, and the rodless chamber of the right hydraulic cylinder can receive or return oil. When the electrical interface Y11 connected to the right locking valve is energized, the right locking valve is unidirectionally open, and the rodless chamber of the right hydraulic cylinder can only receive oil. When the electrical interface Y14 connected to the left floating valve is not energized, the left floating valve is unidirectionally open, and the rod chamber of the left hydraulic cylinder can only receive oil. When the electrical interface Y14 connected to the left floating valve is energized, the left floating valve is bidirectionally open, and the rod chamber of the left hydraulic cylinder can receive or return oil. When the electrical interface Y12 connected to the right floating valve is not energized, the right floating valve is unidirectionally open, and the rod chamber of the right hydraulic cylinder can only receive oil. When the electrical interface Y12 connected to the right floating valve is energized, the right floating valve is bidirectionally open, and the rod chamber of the left hydraulic cylinder can receive or return oil.

[0013] Optionally, it also includes: Overflow valve one, with its oil inlet connected to port P of the control valve block; Overflow valve two, the oil inlet is connected to the Pa port of the flow valve; Overflow valve three, the oil inlet is connected to the second port of the synchronous flow divider and combiner valve; Overflow valve four, the oil inlet is connected to the third port of the synchronous flow divider and combiner valve; The rodless chamber pressure sensor of the hydraulic cylinder is connected to the second port of the loading pressure valve. The rod chamber pressure sensor of the left hydraulic cylinder is connected to the rod chamber of the left hydraulic cylinder; The rod chamber pressure sensor of the right hydraulic cylinder is connected to the rod chamber of the right hydraulic cylinder; The displacement sensor for the left hydraulic cylinder is connected to the cylinder rod of the left hydraulic cylinder. The displacement sensor for the right hydraulic cylinder is connected to the cylinder rod of the right hydraulic cylinder.

[0014] In a second aspect, the present invention provides a control method for a multimodal adaptive hydraulic control system for a paver screed, comprising: When the target paving thickness is received and a pre-adjustment is required before paving starts, the system automatically matches the pre-adjustment with the synchronization mode. The hydraulic oil output from the P port of the control valve block passes through the Pb port of the flow valve, the pilot valve, the P2 port of the lifting valve, the B2 port of the lifting valve, and the speed control valve to the first port of the synchronization flow divider and combiner valve. The hydraulic oil output from the P port of the control valve block is split in the synchronization flow divider and combiner valve and supplies oil to the rod chambers of the left and right hydraulic cylinders through the second and third ports of the synchronization flow divider and combiner valve, respectively. The screed rises, and the rodless chambers of the left and right hydraulic cylinders return oil through the loading pressure valve and the lifting valve to the T port of the control valve block. At this time, the left and right synchronization of the screed's rise is adjusted by the synchronization flow divider and combiner valve. Before paving begins, a pre-adjustment for descent is required. The pre-adjustment is automatically matched with the synchronization mode. Hydraulic oil output from the P port of the control valve block is simultaneously supplied to the rodless chambers of the left and right hydraulic cylinders via the Pb port of the flow valve, the pilot valve, the P2 port of the lifting valve, the A2 port of the lifting valve, and the loading pressure valve, causing the screed to fall. At this time, the return oil from the rod chambers of the left and right hydraulic cylinders flows through the left and right floating valves into the second and third ports of the synchronization flow divider and combiner valve, respectively. Then, the oil from the first port of the synchronization flow divider and combiner valve is connected to the T port of the control valve block via the reverse speed control circuit of the speed control valve and the T2 port of the lifting valve. The left-right synchronization of the screed's descent is adjusted by the synchronization flow divider and combiner valve, and the screed's descent speed is adjusted by the speed control valve. Small displacement synchronization deviations between the left and right hydraulic cylinders are compensated using electronic cross-coupling between the left and right locking valves and the left and right floating valves. When the pre-adjustment is completed and paving is about to begin, the active locking mode is automatically matched. At this time, the left locking valve, right locking valve, left floating valve and right floating valve are all one-way cut off. The rod chamber and rodless chamber of the left hydraulic cylinder and the rod chamber and rodless chamber of the right hydraulic cylinder can only enter oil and cannot return oil, thus realizing the active locking of the screed. When the pre-paving is completed, the paving thickness is stable and the target paving thickness is reached, the paving floating mode is automatically matched; the left locking valve, right locking valve, left floating valve and right floating valve are all bidirectionally connected, and the rod chamber and rodless chamber of the left hydraulic cylinder and the right hydraulic cylinder are connected to the T port of the control valve block; When the paver is detected to be in asymmetrical paving, curved paving, or uphill / downhill conditions, the automatic matching of the adaptive pressure regulation mode's load reduction and anti-fall control sub-mode is activated. Hydraulic oil output from the P port of the control valve block is diverted through the Pa port of the flow valve and the load reduction pressure switch valve to the inlet ports of load reduction pressure valve one and load reduction pressure valve two. Hydraulic oil output from the outlet port of load reduction pressure valve one is diverted through the first port and the second port of the synchronous diversion and combination valve to the rod chamber of the left hydraulic cylinder. Hydraulic oil output from the outlet port of load reduction pressure valve two... Oil is fed into the rod chamber of the right hydraulic cylinder through the third port and the first port of the load reduction pressure switching valve; the rodless chambers of the left and right hydraulic cylinders are connected to the T port of the control valve block through the circuit valve; the pressure of the rod chamber of the left hydraulic cylinder is electrically proportionally regulated by the first load reduction pressure valve, and the pressure of the rod chamber of the right hydraulic cylinder is electrically proportionally regulated by the second load reduction pressure valve, so that the actual pressure of the rod chambers of the left and right hydraulic cylinders is stabilized at the corresponding target value, and the grounding pressure on the left and right sides of the ironing plate is adjusted to stabilize to the set state; When the paver needs to stop to wait for material during normal floating paving, and the paver's travel speed is 0 for a period of time exceeding the set time threshold, it will automatically match the load reduction and anti-fall control sub-mode of the adaptive pressure adjustment mode. When the paver restarts after a material standby, if the ambient temperature, initial screed temperature, asphalt mixture temperature, and paving start-up status simultaneously meet the anti-creep trigger conditions, the automatic matching of the adaptive pressure adjustment mode's loading anti-creep control sub-mode will automatically activate. Hydraulic oil output from the P port of the control valve block will simultaneously supply oil to the rodless chambers of both the left and right hydraulic cylinders via the pilot valve, the P2 port of the lifting valve, the A2 port of the lifting valve, and the loading pressure valve. The pressure in the rodless chambers of the left and right hydraulic cylinders will be electrically proportionally regulated by the loading pressure valve. Based on the target value, the actual pressure in the rodless chambers of the hydraulic cylinders will be controlled in a closed-loop pressure loop to stabilize the actual pressure in the rodless chambers of the left and right hydraulic cylinders at the corresponding target value. During the execution of the loading anti-creep control sub-mode, if the screed bottom plate temperature reaches the set temperature threshold and the structural temperature difference is less than the set value, the loading anti-creep control sub-mode will exit, and the paving floating mode will be automatically matched again.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a multimodal adaptive hydraulic control system for a paver screed, comprising a left hydraulic cylinder, a right hydraulic cylinder, and a control valve block. The left and right hydraulic cylinders are respectively used to connect the left and right paving sections of the screed. The P port of the control valve block is connected in series with a flow valve and is also connected to the Pa and Pb ports of the flow valve. The Pb port of the flow valve is connected to the P2 port of a lifting valve via a pilot valve, which controls the oil circuit connection between the Pb port of the flow valve and the P2 port of the lifting valve. The P2 port of the lifting valve is connected to either the A2 or B2 port of the lifting valve. The A2 port of the lifting valve is connected in parallel to the rodless chambers of the left and right hydraulic cylinders via a loading pressure valve. The inlets of the rodless chambers of the left and right hydraulic cylinders are respectively equipped with a left locking valve and a right locking valve. The B2 port of the lifting valve is connected to a speed regulating valve. The first port of the synchronous flow divider and combiner valve is connected; the first port of the synchronous flow divider and combiner valve is connected to the T port of the control valve block via a loop valve; the first port of the synchronous flow divider and combiner valve is connected in parallel with the second and third ports via a synchronous valve; the second port of the synchronous flow divider and combiner valve is connected to the rod chamber of the left hydraulic cylinder via a left floating valve; the third port of the synchronous flow divider and combiner valve is connected to the second port of the unloading pressure switching valve, and the first port of the unloading pressure switching valve is connected to the rod chamber of the right hydraulic cylinder via a right floating valve; the first port of the unloading pressure switching valve is connected to either the second or third port; the Pa port of the flow valve is connected in parallel with the inlet of unloading pressure valve one and unloading pressure valve two via an unloading pressure switching valve, the outlet of unloading pressure valve one is connected to the first port of the synchronous flow divider and combiner valve; the outlet of unloading pressure valve two is connected to the third port of the unloading pressure switching valve. The present invention sets up the above hydraulic circuit, which can realize adaptive matching and switching of various working modes by controlling the valve position and valve core opening of each valve body. It has multiple active control functions such as locking, load reduction, and anti-climbing, which significantly improves the paver's adaptability to complex working conditions. Attached Figure Description

[0016] Figure 1 A hydraulic schematic diagram of a multimodal adaptive hydraulic control system for a paver screed provided in an embodiment of the present invention; Figure 2 This is an electrical control architecture diagram of a multimodal adaptive hydraulic control system for a paver screed provided in an embodiment of the present invention; Figure 3 The control flowchart of a multimodal adaptive hydraulic control system for a paver screed is provided in an embodiment of the present invention.

[0017] Numbering on the map: 1. Pilot valve; 2. Lift valve; 3. Speed ​​control valve; 4. Synchronization valve; 5. Circuit valve; 6. Load shedding pressure switch valve; 7. Control valve block; 7.1. Load shedding pressure valve II; 7.2. Load shedding pressure valve I; 7.3. Relief valve IV; 7.4. Relief valve III; 7.5. Load shedding pressure switching valve; 7.6. Synchronization flow divider / combiner valve; 7.7. Loading pressure valve; 7.8. Relief valve II; 7.9. Relief valve I; 7.10. Flow rate... 8. Right hydraulic cylinder; 9. Left hydraulic cylinder; 10.1 Right floating valve; 10.2 Left floating valve; 11.1 Right locking valve; 11.2 Left locking valve; 12.1 Right hydraulic cylinder rod chamber pressure sensor; 12.2 Left hydraulic cylinder rod chamber pressure sensor; 12.3 Hydraulic cylinder rodless chamber pressure sensor; 13.1 Right hydraulic cylinder displacement sensor; 13.2 Left hydraulic cylinder displacement sensor. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Combination Figure 1 This embodiment provides a multimodal adaptive hydraulic control system for a paver screed, including a hydraulic actuator, a hydraulic control valve group, a multi-source sensor group, and a controller.

[0020] The hydraulic actuator includes a right hydraulic cylinder 8 and a left hydraulic cylinder 9 symmetrically arranged on both sides of the rear end of the paver body. The right hydraulic cylinder 8 and the left hydraulic cylinder 9 are used to control the lifting and lowering actions and the force state of the left and right paving sections of the screed, respectively. The hydraulic control valve group mainly consists of a pilot valve 1, a lifting valve 2, a speed regulating valve 3, a synchronizing valve 4, a circuit valve 5, a load reduction pressure switching valve 6, a control valve block 7, a left floating valve 10.2 and a right floating valve 10.1, a right locking valve 11.1 and a left locking valve 11.2; the control valve block 7 internally houses a load reduction pressure valve 7.1, a load reduction pressure valve 7.2, a load reduction pressure switching valve 7.5, a synchronizing flow divider / combiner valve 7.6, a loading pressure valve 7.7, and a flow valve 7.10; the pilot valve 1 is a two-position four-way solenoid directional valve with a mid-position function of type II and a reversing position of type X; The lifting valve 2 is a three-position four-way solenoid directional valve with a neutral position function of type N; the speed regulating valve 3 is an integrated check valve with forward conduction and reverse speed regulation; the synchronizing valve 4 and the circuit valve 5 are two-position four-way solenoid directional valves with a neutral position function of type II and a reversing position of type O; the unloading pressure switch valve 6 is a two-position four-way solenoid directional valve with a neutral position function of type X and a reversing position of type II; the unloading pressure valve 7.1 and the unloading pressure valve 7.2 are electro-proportional pressure reducing valves with pressure reducing ports connected in series with hydraulic control check valves; the loading pressure valve 7.7 is an electro-proportional pressure reducing valve with parallel check valves.

[0021] The multi-source sensor group is electrically connected to the controller and is used to collect the system's status parameters and environmental parameters in real time. The multi-source sensor group includes at least a displacement sensor for detecting the piston rod displacement of the right hydraulic cylinder 8 and the left hydraulic cylinder 9, a pressure sensor for detecting the pressure in the rod chamber and rodless chamber of the right hydraulic cylinder 8 and the left hydraulic cylinder 9, a temperature sensor for detecting the ambient temperature, the temperature of the asphalt mixture to be paved on the front side of the screed, and the temperature of the screed bottom plate, and a vehicle speed sensor for detecting the paver's driving status. The pressure sensors specifically include a rodless chamber pressure sensor 12.3 connected to the second port of the loading pressure valve 7.7, a rod chamber pressure sensor 12.2 connected to the rod chamber of the left hydraulic cylinder 9, and a rod chamber pressure sensor 12.1 connected to the rod chamber of the right hydraulic cylinder 8. The displacement sensors include a left hydraulic cylinder displacement sensor 13.2 connected to the piston rod of the left hydraulic cylinder 9 and a right hydraulic cylinder displacement sensor 13.1 connected to the piston rod of the right hydraulic cylinder 8.

[0022] The controller is electrically connected to the hydraulic control valve group and the multi-source sensor group. Its characteristic is that the controller is configured to automatically identify the stage and working condition of the paving operation based on real-time feedback signals from the multi-source sensor group and / or external input commands, and control the hydraulic control valve group to execute corresponding control logic, enabling the system to adaptively switch between multiple working modes, including pre-adjustment and synchronization mode, paving floating mode, active locking mode, and adaptive pressure regulation mode. The controller can automatically identify the working condition and switch control modes based on sensor signals (vehicle speed, pressure, temperature), reducing operator skill requirements and improving the level of construction standardization.

[0023] like Figure 2This is a structural block diagram of the electrical control system in this embodiment, including a control panel, a controller, and pressure sensors electrically connected to the controller's input terminals: a left hydraulic cylinder rod chamber pressure sensor 12.2, a right hydraulic cylinder pressure sensor 12.1, a hydraulic cylinder rodless chamber pressure sensor 12.3, a left hydraulic cylinder displacement sensor 13.2, a right hydraulic cylinder displacement sensor 13.1, an ambient temperature sensor, an asphalt mixture temperature sensor, a screed bottom plate temperature sensor, and a vehicle speed sensor. The hydraulic control system, electrically connected to the controller's output terminals, includes corresponding interfaces for the solenoid valves: pilot valve 1 (Y1), lifting valve 2 (Y2), lifting valve 2 (Y3), synchronizing valve 4 (Y4), loop valve 5 (Y5), and unloading pressure switch valve 6 (Y6). The electrical interfaces are as follows: Y7 for load pressure valve 7.7, Y8 for load reduction pressure switching valve 7.5, Y9 for load reduction pressure valve 1, Y10 for load reduction pressure valve 2, Y11 for right hydraulic cylinder locking valve 11.1, Y12 for right floating valve 10.1, Y13 for left hydraulic cylinder locking valve 11.2, and Y14 for left floating valve 10.2. The controller is configured to automatically identify the stage and working condition of the paving operation based on the real-time feedback signals from the multi-source sensor group and / or external input commands, control the hydraulic control valve group to execute corresponding control logic, and enable the system to adaptively switch between multiple working modes, including pre-adjustment and synchronization mode, paving floating mode, active locking mode, and adaptive pressure adjustment mode.

[0024] Specifically, the left hydraulic cylinder 9 and the right hydraulic cylinder 8 are used to connect the left and right paving sections of the screed, respectively; the control valve block 7 is used to connect the P port of the external oil source in series with the flow valve 7.10, and to connect the Pa port and Pb port of the flow valve 7.10; the Pb port of the flow valve 7.10 is connected to the P2 port of the lifting valve 2 via the pilot valve 1, and the pilot valve 1 is used to control the oil circuit connection between the Pb port of the flow valve 7.10 and the P2 port of the lifting valve 2; the P2 port of the lifting valve 2 is connected to... The lifting valve's A2 port or B2 port is connected; the lifting valve's A2 port is connected in parallel to the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 via the loading pressure valve 7.7; the left locking valve 11.2 and the right locking valve 11.1 are respectively installed at the oil inlet of the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8; the lifting valve's B2 port is connected to the first port of the synchronous flow divider and combiner valve 7.6 via the speed control valve 3; the first port of the synchronous flow divider and combiner valve 7.6 is connected to the T port of the control valve block 7 via the loop valve 5.

[0025] The first port of the synchronous flow divider and combiner valve 7.6 is connected in parallel with the second and third ports through the synchronous valve 4; the second port of the synchronous flow divider and combiner valve 7.6 is connected to the rod chamber of the left hydraulic cylinder 9 through the left floating valve 10.2; the third port of the synchronous flow divider and combiner valve is connected to the second port of the load reduction pressure switching valve; the first port of the load reduction pressure switching valve 7.5 is connected to the rod chamber of the right hydraulic cylinder 8 through the right floating valve 10.1; the first port of the load reduction pressure switching valve 7.5 is connected to either the second or third port.

[0026] The Pa port of the flow valve 7.10 is connected in parallel to the inlet of the unloading pressure valve 7.2 and the unloading pressure valve 7.1 via the unloading pressure switching valve 6. The outlet of the unloading pressure valve 7.2 is connected to the first port of the synchronous flow divider and combiner valve 7.6. The outlet of the unloading pressure valve 7.1 is connected to the third port of the unloading pressure switching valve 7.5.

[0027] Specifically, the pilot valve 1's P1 port is connected to the flow valve 7.10's Pb port and is located upstream of the lift valve 2's P2 port. The pilot valve 1's A1 and T1 ports are both connected to the control valve block 7's T port, and its B1 port is connected to the flow valve 7.10's Pb port and is located downstream of the pilot valve's P1 port and upstream of the lift valve 2's P2 port. When the pilot valve 1's electrical interface Y1 is not energized, the pilot valve 1 is in the lower position, with the pilot valve 1's P1 and A1 ports connected, and its T1 and B1 ports connected. The flow valve 7.10's Pb port is connected to the control valve block 7's T port, and the lift valve's A2 port does not receive oil. When the pilot valve 1's electrical interface Y1 is energized, the pilot valve 1 is in the upper position, with the pilot valve 1's P1 and B1 ports connected, and its T1 and A1 ports connected. The flow valve 7.10's Pb port is connected to the lift valve's A2 port via the pilot valve 1.

[0028] When both electrical interfaces Y2 and Y3 connected to the lifting valve 2 are de-energized, the lifting valve 2 is in the neutral position, with both P2 and B2 ports of the lifting valve 2 closed, and A2 and T2 ports connected. The T2 port of the lifting valve 2 is connected to the T port of the control valve block 7. When electrical interface Y2 connected to the lifting valve 2 is energized, the lifting valve 2 is in the upper position, with P2 and B2 ports connected, and A2 and T2 ports connected. When electrical interface Y3 connected to the lifting valve 2 is energized, the lifting valve 2 is in the lower position, with P2 and A2 ports connected, and B2 and T2 ports connected.

[0029] The upper oil port of the speed regulating valve 3 is connected to port B2 of the lifting valve; the lower oil port of the speed regulating valve 3 is connected to the first port of the synchronous flow divider and collector valve 7.6; a parallel forward oil circuit and a reverse speed regulating oil circuit are provided between the upper oil port and the lower oil port of the speed regulating valve 3; the upper oil port of the speed regulating valve 3 is unidirectionally connected to the lower oil port through a check valve on the forward oil circuit; the lower oil port of the speed regulating valve 3 is connected to the upper oil port through an electro-proportional throttling orifice.

[0030] This embodiment includes a synchronization valve 4. The P3 and T3 ports of the synchronization valve 4 are both connected to the first port of the synchronization diverter / combiner valve 7.6. The A3 and B3 ports of the synchronization valve 4 are connected to the second and third ports of the synchronization diverter / combiner valve 7.6, respectively. When the electrical interface Y4 of the synchronization valve 4 is not energized, the P3 and A3 ports of the synchronization valve 4 are connected, and the T3 and B3 ports of the synchronization valve 4 are connected. When the electrical interface Y4 of the synchronization valve 4 is energized, the P3, A3, T3 and B3 ports of the synchronization valve 4 are all cut off.

[0031] The P4 and T4 ports of the circuit valve 5 are both connected to the T port of the control valve block 7, and the A4 port of the circuit valve 5 is connected to the second port of the loading pressure valve 7.7. The first port of the loading pressure valve 7.7 is connected to the A2 port of the lifting valve 2, and the second port of the loading pressure valve 7.7 is connected in parallel to the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8. By controlling the electrical interface Y7 connected to the loading pressure valve 7.7, the valve core opening of the loading pressure valve 7.7 can be controlled to control the pressure in the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8.

[0032] The P5 port of the load relief pressure switch valve 6 is connected to the Pa port of the flow valve; the A5 port is connected in parallel to the oil inlet of the first load relief pressure valve 7.2 and the second load relief pressure valve 7.1; the B5 port is connected to the T port of the control valve block 7; and the T5 port is connected to the T port of the control valve block 7. When the electrical interface Y6 connected to the load relief pressure switch valve 6 is not energized, the P5 port and B5 port of the load relief pressure switch valve 6 are connected, and the T5 port and A5 port of the load relief pressure switch valve 6 are connected. When energized, the P5 and A5 ports of the load relief pressure switch valve 6 are connected, and the T5 and B5 ports of the load relief pressure switch valve 6 are connected. By controlling the electrical interface Y9 connected to the load relief pressure valve 7.2, the valve core opening of the load relief pressure valve 7.2 can be controlled to control the rod chamber pressure of the left hydraulic cylinder 9. By controlling the electrical interface Y10 connected to the load relief pressure valve 7.1, the valve core opening of the load relief pressure valve 7.1 can be controlled to control the rod chamber pressure of the right hydraulic cylinder 8.

[0033] When the electrical interface Y13 connected to the left locking valve 11.2 is not energized, the left locking valve 11.2 is bidirectionally open, and the rodless chamber of the left hydraulic cylinder 9 can receive or return oil; when the electrical interface Y13 connected to the left locking valve 11.2 is energized, the left locking valve 11.2 is unidirectionally open, and the rodless chamber of the left hydraulic cylinder 9 can only receive oil.

[0034] When the electrical interface Y11 connected to the right locking valve 11.1 is not energized, the right locking valve 11.1 is bidirectionally open, and the rodless chamber of the right hydraulic cylinder 8 can receive or return oil; when the electrical interface Y11 connected to the right locking valve 11.1 is energized, the right locking valve 11.1 is unidirectionally open, and the rodless chamber of the right hydraulic cylinder 8 can only receive oil.

[0035] When the electrical interface Y14 connected to the left floating valve 10.2 is not energized, the left floating valve 10.2 is unidirectionally open, and the rod chamber of the left hydraulic cylinder 9 can only receive oil; when the electrical interface Y14 connected to the left floating valve 10.2 is energized, the left floating valve 10.2 is bidirectionally open, and the rod chamber of the left hydraulic cylinder 9 can receive or return oil.

[0036] When the electrical interface Y12 connected to the right floating valve 10.1 is not energized, the right floating valve 10.1 is unidirectionally open, and the rod chamber of the right hydraulic cylinder 8 can only receive oil; when the electrical interface Y12 connected to the right floating valve 10.1 is energized, the right floating valve 10.1 is bidirectionally open, and the rod chamber of the left hydraulic cylinder 9 can receive or return oil.

[0037] In this embodiment, the oil inlet of overflow valve 1 7.9 is connected to the P port of the control valve block 7; the oil inlet of overflow valve 2 7.8 is connected to the Pa port of the flow valve 7.10; the oil inlet of overflow valve 3 7.4 is connected to the second port of the synchronous flow divider and combiner valve 7.6; and the oil inlet of overflow valve 4 7.3 is connected to the third port of the synchronous flow divider and combiner valve 7.6. The specific control method is explained below. The controller collects system parameters in real time through a multi-source sensor group to monitor the system's operating status. The controller fuses the collected status data and, in conjunction with externally input operation commands, automatically identifies the current stage and working condition of the paving operation and matches the corresponding working mode. Based on the matched working mode, the controller calls the corresponding control algorithm to generate control signals and outputs them to the hydraulic control valve group. The hydraulic control valve group independently and continuously adjusts the pressure of the rodless chamber and / or rod chamber of the hydraulic cylinder, thereby controlling the stress state of the screed and executing closed-loop control of the corresponding mode. The working modes include at least a pre-adjustment synchronization mode, a paving floating mode, an active locking mode, and an adaptive pressure adjustment mode.

[0038] Specifically, the methods for matching working modes include: Upon receiving the target paving thickness and before paving commences, when a pre-adjustment is required, the system automatically matches the pre-adjustment with the synchronization mode. The electrical interfaces Y1 of pilot valve 1, Y2 of lifting valve 2, Y4 of synchronization valve 4, and Y5 of loop valve 5 are energized. The electrical interfaces Y3, Y6, Y7, Y8, Y9, Y10, Y11, Y12, Y13, and Y14 of the remaining solenoid valves are de-energized. The hydraulic oil output from port P of control valve block 7 passes through port Pb of flow valve 7.10, pilot valve 1, and port P2 of lifting valve 2. The B2 port of the lifting valve 2 and the speed control valve 3 reach the first port of the synchronous flow divider and combiner valve 7.6. The hydraulic oil output from the P port of the control valve block 7 is divided in the synchronous flow divider and combiner valve 7.6 and supplied to the rod chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 through the second and third ports of the synchronous flow divider and combiner valve 7.6, raising the ironing plate. The rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 return oil through the loading pressure valve 7.7 and the lifting valve 2 to the T port of the control valve block 7. At this time, the left and right synchronization of the ironing plate rise is adjusted by the synchronous flow divider and combiner valve 7.6.

[0039] When a pre-adjustment for descent is required before paving begins, the system automatically matches the pre-adjustment with the synchronization mode. The electrical interfaces Y1 of pilot valve 1, Y3 of lifting valve 2, Y4 of synchronization valve 4, Y5 of loop valve 5, Y14 of left floating valve 10.2, and Y12 of right floating valve 10.1 are energized. The electrical interfaces Y2, Y6, Y7, Y8, Y9, Y10, Y11, and Y13 of the remaining solenoid valves are de-energized. The P port of control valve block 7 is then activated. The hydraulic oil supplied through the Pb port of flow valve 7.10, pilot valve 1, P2 port of lifting valve 2, A2 port of lifting valve 2, and loading pressure valve 7.7 simultaneously supplies oil to the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8, causing the ironing plate to fall. At this time, the return oil from the rod chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 flows through the left floating valve 10.2 and the right floating valve 10.1 respectively to the second and third ports of the synchronous flow divider and combiner valve 7.6, and then from the first port of the synchronous flow divider and combiner valve 7.6 through the speed control valve 3... The speed regulating oil circuit and the T2 port of the lifting valve 2 are connected to the T port of the control valve block 7. The left and right synchronization of the ironing plate descent is adjusted by the synchronization diverting and combining valve 7.6, and the descent speed of the ironing plate is adjusted by the speed regulating valve 3. The small displacement synchronization deviation between the left hydraulic cylinder 9 and the right hydraulic cylinder 8 is compensated by the electronic cross-coupling of the left locking valve 11.2, the right locking valve 11.1, the left floating valve 10.2, and the right floating valve 10.1. The displacement sensors of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 are collected in real time. The actual displacement signal is used to calculate the position following deviation of the hydraulic cylinders and the synchronous displacement deviation of the left hydraulic cylinder 9 and the right hydraulic cylinder 8. A position closed-loop control algorithm based on electronic cross-coupling is adopted to synchronously drive and compensate for the deviation of the lifting and lowering movements of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 by controlling the left locking valve 11.2, the right locking valve 11.1, the left floating valve 10.2, and the right floating valve 10.1, until the actual displacement of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 reaches the target value and the synchronous deviation is less than the set threshold. This embodiment achieves high-precision synchronous pre-adjustment: through position closed-loop control based on electronic cross-coupling, the initial leveling problem of ultra-wide screeds is solved, significantly improving the efficiency of construction preparation.

[0040] When pre-adjustment is completed and paving is about to begin, the automatic active locking mode is matched. At this time, the electrical interface Y13 of the left locking valve 11.2 and the electrical interface Y11 of the right locking valve 11.1 are energized, while the electrical interfaces Y1, Y2, Y3, Y4, Y5, Y6, Y7, Y8, Y9, Y10, Y12, and Y14 of the other solenoid valves are de-energized. The left locking valve 11.2, the right locking valve 11.1, the left floating valve 10.2, and the right floating valve 10.1 are all unidirectionally cut off. The rod chamber and rodless chamber of the left hydraulic cylinder 9 and the rod chamber and rodless chamber of the right hydraulic cylinder 8 can only receive oil and cannot return oil, thus achieving active locking of the screed.

[0041] When pre-paving is completed, and the paving thickness is stable and reaches the target paving thickness, the paving floating mode is automatically matched. At this time, the electrical interface Y14 of the left floating valve 10.2 and the electrical interface Y12 of the right floating valve 10.1 are energized, while the electrical interfaces Y1, Y2, Y3, Y4, Y5, Y6, Y7, Y8, Y9, Y10, Y11, and Y13 of the other solenoid valves are de-energized. The left locking valve 11.2, the right locking valve 11.1, the left floating valve 10.2, and the right floating valve 10.1 are all bidirectionally connected. The rod-side chamber and the rodless chamber of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 are connected to the T-port of the control valve block 7. At the same time, the feedback signals from the displacement sensor, pressure sensor, and vehicle speed sensor are collected in real time to monitor the floating state of the screed. When the displacement deviation or pressure fluctuation exceeds the set threshold, an abnormal alarm is triggered.

[0042] When the paver is detected to be in asymmetrical paving, curved paving, or uphill / downhill conditions, the automatic matching of the adaptive pressure regulation mode's load reduction and anti-fall control sub-mode is activated. At this time, the electrical interfaces Y6 of the load reduction pressure switch valve 6, Y9 of the load reduction pressure valve 1 7.2, Y10 of the load reduction pressure valve 2 7.1, Y8 of the load reduction pressure switching valve 7.5, Y14 of the left floating valve 10.2, and Y12 of the right floating valve 10.1 are energized, while the electrical interfaces Y1, Y2, Y3, Y4, Y5, Y7, Y11, and Y13 of the remaining solenoid valves are de-energized. The hydraulic oil output from the P port of the control valve block 7 passes through the Pa port of the flow valve 7.10 and is diverted by the load reduction pressure switch valve 6 to the inlet of the load reduction pressure valve 1 7.2 and the load reduction pressure valve 2 7.1. The load reduction pressure valve 1 7... The hydraulic oil output from the outlet of hydraulic cylinder 2 passes through the first port and the second port of the synchronous flow divider and combiner valve 7.6 and enters the rod chamber of the left hydraulic cylinder 9; the hydraulic oil output from the outlet of the unloading pressure valve 7.1 passes through the third port and the first port of the unloading pressure switching valve 7.5 and enters the rod chamber of the right hydraulic cylinder 8; the rodless chambers of the left and right hydraulic cylinders 9 and 8 are connected to the T port of the control valve block 7 via the circuit valve 5; the pressure of the rod chamber of the left hydraulic cylinder 9 is electrically proportionally regulated by the unloading pressure valve 7.2, and the pressure of the rod chamber of the right hydraulic cylinder 8 is electrically proportionally regulated by the unloading pressure valve 7.1, so that the actual pressure of the rod chambers of the left and right hydraulic cylinders 9 and 8 is stabilized at the corresponding target value, and the grounding pressure on the left and right sides of the ironing plate is adjusted to stabilize to the set state.

[0043] When the paver needs to stop to wait for material during normal floating paving, if the paver's travel speed is 0 and the duration exceeds the set time threshold, it will automatically match the load reduction and anti-fall control sub-mode of the adaptive pressure adjustment mode to keep the screed in the same stress as when it is stationary compared to when it is floating paving, thus avoiding the screed from causing indentations on the road surface after the machine stops.

[0044] When the paver restarts after a material standby, if the ambient temperature, initial screed temperature, asphalt mixture temperature, and paving start-up status simultaneously meet the anti-creep trigger conditions, the automatic matching of the adaptive pressure adjustment mode's loading anti-creep control sub-mode will activate. At this time, the loading pressure valve in the control valve group will perform closed-loop pressure control on the rodless chamber of the cylinder, applying a downward loading force to counteract the thermal warping force of the screed. Simultaneously, the electrical interfaces Y1 (pilot valve 1), Y3 (lift valve 2), Y7 (loading pressure valve 7.7), Y5 (loop valve 5), Y14 (left floating valve 10.2), and Y12 (right floating valve 10.1) will be energized, and the electrical interfaces of the remaining solenoid valves Y2, Y4, Y6, Y8, Y9, and Y10 will also be energized. Both Y11 and Y13 are de-energized; the hydraulic oil output from the P port of control valve block 7 supplies oil to the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 simultaneously through the pilot valve 1, the P2 port of the lifting valve 2, the A2 port of the lifting valve 2, and the loading pressure valve 7.7; the pressure of the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 is electrically proportionally regulated by the loading pressure valve 7.7, and the actual pressure of the rodless chambers of the hydraulic cylinders is controlled in a closed loop according to the target value, so that the actual pressure of the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8 is stabilized at the corresponding target value; when executing the loading anti-climb control sub-mode, if the temperature of the screed bottom plate reaches the set temperature threshold and the structural temperature difference is less than the set value, the loading anti-climb control sub-mode is exited, and the paving floating mode is automatically matched again.

[0045] This embodiment, through active pressure control, can effectively eliminate common quality defects such as asymmetrical paving indentations, parking joint defects, and low-temperature slab formation, thereby improving pavement smoothness and consistency. Specifically, an adaptive pressure calculation model based on ambient temperature, initial temperature of the ironing plate, and temperature of the mixture is built in to generate target anti-climb pressure for the rodless chambers of the left hydraulic cylinder 9 and the right hydraulic cylinder 8; the pressure of the rodless chambers of the cylinders is controlled in a closed loop through the electro-proportional loading pressure valve 7.7 to apply a downward loading force to counteract the thermal warping force of the ironing plate; the temperature of the bottom plate of the ironing plate is monitored in real time, and when the temperature of the bottom plate reaches the set threshold and the structural temperature difference is less than the set value, the anti-climb pressure is gradually reduced and the sub-mode is exited. In addition, the controller also has a built-in fault diagnosis and safety protection module, which is configured to: monitor the working status of the multi-source sensor group and the hydraulic control valve group in real time, identify abnormal sensor signals, abnormal hydraulic system pressure, and abnormal power supply and control of the electrical system, and trigger corresponding alarm prompts; when an emergency stop command or serious fault is detected, the valve group control power supply is immediately cut off, so that the floating valve returns to the neutral position locking cylinder, which plays a role in locking and protecting the actuator.

[0046] Of course, the above embodiments are merely preferred embodiments of the present invention and are not limited thereto. Different implementation methods can be obtained by making targeted adjustments according to actual needs. All equivalent changes or improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A multimodal adaptive hydraulic control system for a paver screed, characterized in that, include: The left and right hydraulic cylinders are used to connect the left and right paving sections of the screed, respectively. The control valve block has its P port connected in series with the flow valve and connected to the Pa and Pb ports of the flow valve. The Pb port of the flow valve is connected to the P2 port of the lift valve through a pilot valve. The pilot valve is used to control the oil circuit connection between the Pb port of the flow valve and the P2 port of the lift valve. The P2 port of the lift valve is connected to the A2 or B2 port of the lift valve. The A2 port of the lifting valve is connected in parallel to the rodless chambers of the left and right hydraulic cylinders via a loading pressure valve; the oil inlet of the rodless chambers of the left and right hydraulic cylinders is provided with a left locking valve and a right locking valve, respectively. The B2 port of the lifting valve is connected to the first port of the synchronous flow divider and combiner valve via the speed control valve; the first port of the synchronous flow divider and combiner valve is connected to the T port of the control valve block via the loop valve. The first port of the synchronous flow divider and combiner valve is connected in parallel with the second and third ports through a synchronous valve; the second port of the synchronous flow divider and combiner valve is connected to the rod chamber of the left hydraulic cylinder through a left floating valve; the third port of the synchronous flow divider and combiner valve is connected to the second port of the load reduction pressure switching valve, and the first port of the load reduction pressure switching valve is connected to the rod chamber of the right hydraulic cylinder through a right floating valve. The first port of the unloading pressure switching valve is connected to the second or third port; The Pa port of the flow valve is connected in parallel to the inlet of the first and second load relief pressure valves via the load relief pressure switching valve. The outlet of the first load relief pressure valve is connected to the first port of the synchronous flow divider and combiner valve. The outlet of the second load relief pressure valve is connected to the third port of the load relief pressure switching valve.

2. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, The pilot valve's P1 port is connected to the flow valve's Pb port and is located upstream of the lift valve's P2 port. The pilot valve's A1 port and T1 port are both connected to the control valve block's T port. The pilot valve's B1 port is connected to the flow valve's Pb port and is located downstream of the pilot valve's P1 port and upstream of the lift valve's P2 port. When the pilot valve's electrical interface Y1 is not energized, the pilot valve is in the lower position, the pilot valve's P1 port and A1 port are connected, the pilot valve's T1 port and B1 port are connected, the flow valve's Pb port is connected to the control valve block's T port, and the lift valve's A2 port does not receive oil. When the electrical interface Y1 of the pilot valve is energized, the pilot valve is in the upper position, the P1 port and B1 port of the pilot valve are connected, the T1 port and A1 port are connected, and the Pb port of the flow valve is connected to the A2 port of the lift valve through the pilot valve.

3. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, When neither electrical interface Y2 nor electrical interface Y3 connected to the lifting valve is energized, the lifting valve is in the neutral position, the P2 port and B2 port of the lifting valve are both closed, the A2 port and T2 port of the lifting valve are connected, and the T2 port of the lifting valve is connected to the T port of the control valve block. When the electrical interface Y2 connected to the lifting valve is energized, the lifting valve is in the upper position, and the P2 port and B2 port of the lifting valve are connected, and the A2 port and T2 port are connected. When the electrical interface Y3 connected to the lifting valve is energized, the lifting valve is in the lower position, and the P2 port and A2 port of the lifting valve are connected, and the B2 port and T2 port are connected.

4. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, The upper oil port of the speed regulating valve is connected to the B2 port of the lifting valve; the lower oil port of the speed regulating valve is connected to the first port of the synchronous flow divider and combiner valve. The speed regulating valve has a parallel forward oil passage and a reverse speed regulating oil passage between its upper and lower oil ports. The upper oil port of the speed regulating valve is unidirectionally connected to the lower oil port via a check valve on the forward oil circuit. The lower oil port of the speed control valve is connected to the upper oil port through an electro-proportional throttling orifice.

5. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, Also includes: The synchronizing valve has its P3 and T3 ports connected to the first port of the synchronizing flow divider and combiner valve, and its A3 and B3 ports connected to the second and third ports of the synchronizing flow divider and combiner valve, respectively. When the electrical interface Y4 of the synchronizing valve is not energized, the P3 port and A3 port of the synchronizing valve are connected, and the T3 port and B3 port of the synchronizing valve are connected. When the electrical interface Y4 of the synchronizing valve is energized, ports P3, A3, T3, and B3 of the synchronizing valve are all shut off.

6. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, The P4 port and T4 port of the circuit valve are both connected to the T port of the control valve block, and the A4 port of the circuit valve is connected to the second port of the loading pressure valve. The first port of the loading pressure valve is connected to the A2 port of the lifting valve, and the second port of the loading pressure valve is connected in parallel to the rodless chambers of the left and right hydraulic cylinders. By controlling the electrical interface Y7 connected to the loading pressure valve, the valve core opening of the loading pressure valve can be controlled to control the rodless chamber pressure of the left and right hydraulic cylinders.

7. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, The P5 port of the unloading pressure switch valve is connected to the Pa port of the flow valve, the A5 port is connected in parallel to the oil inlet of unloading pressure valve one and unloading pressure valve two, the B5 port is connected to the T port of the control valve block, and the T5 port is connected to the T port of the control valve block. When the electrical interface Y6 connected to the load reduction pressure switch valve is not energized, the P5 port and B5 port of the load reduction pressure switch valve are connected, and the T5 port and A5 port of the load reduction pressure switch valve are connected. When the electrical interface Y6 connected to the load reduction pressure switch valve is energized, the P5 port and A5 port of the load reduction pressure switch valve are connected, and the T5 port and B5 port of the load reduction pressure switch valve are connected. By controlling the electrical interface Y9 connected to the unloading pressure valve, the valve core opening of the unloading pressure valve can be controlled to control the rod chamber pressure of the left hydraulic cylinder. By controlling the electrical interface Y10 connected to the second load relief pressure valve, the valve core opening of the second load relief pressure valve can be controlled to control the rod chamber pressure of the right hydraulic cylinder.

8. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, When the electrical interface Y13 connected to the left locking valve is not energized, the left locking valve is bidirectionally open, and the rodless chamber of the left hydraulic cylinder can receive or return oil. When the electrical interface Y13 connected to the left locking valve is energized, the left locking valve is unidirectionally open, and the rodless chamber of the left hydraulic cylinder can only receive oil. When the electrical interface Y11 connected to the right locking valve is not energized, the right locking valve is bidirectionally open, and the rodless chamber of the right hydraulic cylinder can receive or return oil. When the electrical interface Y11 connected to the right locking valve is energized, the right locking valve is unidirectionally open, and the rodless chamber of the right hydraulic cylinder can only receive oil. When the electrical interface Y14 connected to the left floating valve is not energized, the left floating valve is unidirectionally open, and the rod chamber of the left hydraulic cylinder can only receive oil. When the electrical interface Y14 connected to the left floating valve is energized, the left floating valve is bidirectionally open, and the rod chamber of the left hydraulic cylinder can receive or return oil. When the electrical interface Y12 connected to the right floating valve is not energized, the right floating valve is unidirectionally open, and the rod chamber of the right hydraulic cylinder can only receive oil. When the electrical interface Y12 connected to the right floating valve is energized, the right floating valve is bidirectionally open, and the rod chamber of the left hydraulic cylinder can receive or return oil.

9. The multimodal adaptive hydraulic control system for a paver screed according to claim 1, characterized in that, Also includes: Overflow valve one, with its oil inlet connected to port P of the control valve block; Overflow valve two, the oil inlet is connected to the Pa port of the flow valve; Overflow valve three, the oil inlet is connected to the second port of the synchronous flow divider and combiner valve; Overflow valve four, the oil inlet is connected to the third port of the synchronous flow divider and combiner valve; The rodless chamber pressure sensor of the hydraulic cylinder is connected to the second port of the loading pressure valve. The rod chamber pressure sensor of the left hydraulic cylinder is connected to the rod chamber of the left hydraulic cylinder; The rod chamber pressure sensor of the right hydraulic cylinder is connected to the rod chamber of the right hydraulic cylinder; The displacement sensor for the left hydraulic cylinder is connected to the cylinder rod of the left hydraulic cylinder. The displacement sensor for the right hydraulic cylinder is connected to the cylinder rod of the right hydraulic cylinder.

10. A control method for a multimodal adaptive hydraulic control system for a paver screed, characterized in that, include: When the target paving thickness is received and a pre-adjustment is required before paving starts, the system automatically matches the pre-adjustment with the synchronization mode. The hydraulic oil output from the P port of the control valve block passes through the Pb port of the flow valve, the pilot valve, the P2 port of the lifting valve, the B2 port of the lifting valve, and the speed control valve to the first port of the synchronization flow divider and combiner valve. The hydraulic oil output from the P port of the control valve block is split in the synchronization flow divider and combiner valve and supplies oil to the rod chambers of the left and right hydraulic cylinders through the second and third ports of the synchronization flow divider and combiner valve, respectively. The screed rises, and the rodless chambers of the left and right hydraulic cylinders return oil through the loading pressure valve and the lifting valve to the T port of the control valve block. At this time, the left and right synchronization of the screed's rise is adjusted by the synchronization flow divider and combiner valve. Before paving begins, a pre-adjustment for descent is required. The pre-adjustment is automatically matched with the synchronization mode. Hydraulic oil output from the P port of the control valve block is simultaneously supplied to the rodless chambers of the left and right hydraulic cylinders via the Pb port of the flow valve, the pilot valve, the P2 port of the lifting valve, the A2 port of the lifting valve, and the loading pressure valve, causing the screed to fall. At this time, the return oil from the rod chambers of the left and right hydraulic cylinders flows through the left and right floating valves into the second and third ports of the synchronization flow divider and combiner valve, respectively. Then, the oil from the first port of the synchronization flow divider and combiner valve is connected to the T port of the control valve block via the reverse speed control circuit of the speed control valve and the T2 port of the lifting valve. The left-right synchronization of the screed's descent is adjusted by the synchronization flow divider and combiner valve, and the screed's descent speed is adjusted by the speed control valve. Small displacement synchronization deviations between the left and right hydraulic cylinders are compensated using electronic cross-coupling between the left and right locking valves and the left and right floating valves. When the pre-adjustment is completed and paving is about to begin, the active locking mode is automatically matched. At this time, the left locking valve, right locking valve, left floating valve and right floating valve are all one-way cut off. The rod chamber and rodless chamber of the left hydraulic cylinder and the rod chamber and rodless chamber of the right hydraulic cylinder can only enter oil and cannot return oil, thus realizing the active locking of the screed. When the pre-paving is completed, the paving thickness is stable and the target paving thickness is reached, the paving floating mode is automatically matched; the left locking valve, right locking valve, left floating valve and right floating valve are all bidirectionally connected, and the rod chamber and rodless chamber of the left hydraulic cylinder and the right hydraulic cylinder are connected to the T port of the control valve block; When the paver is detected to be in asymmetrical paving, curved paving, or uphill / downhill conditions, the automatic matching of the adaptive pressure regulation mode's load reduction and anti-fall control sub-mode is activated. Hydraulic oil output from the P port of the control valve block is diverted through the Pa port of the flow valve and the load reduction pressure switch valve to the inlet ports of load reduction pressure valve one and load reduction pressure valve two. Hydraulic oil output from the outlet port of load reduction pressure valve one is diverted through the first port and the second port of the synchronous diversion and combination valve to the rod chamber of the left hydraulic cylinder. Hydraulic oil output from the outlet port of load reduction pressure valve two... Oil is fed into the rod chamber of the right hydraulic cylinder through the third port and the first port of the load reduction pressure switching valve; the rodless chambers of the left and right hydraulic cylinders are connected to the T port of the control valve block through the circuit valve; the pressure of the rod chamber of the left hydraulic cylinder is electrically proportionally regulated by the first load reduction pressure valve, and the pressure of the rod chamber of the right hydraulic cylinder is electrically proportionally regulated by the second load reduction pressure valve, so that the actual pressure of the rod chambers of the left and right hydraulic cylinders is stabilized at the corresponding target value, and the grounding pressure on the left and right sides of the ironing plate is adjusted to stabilize to the set state; When the paver needs to stop to wait for material during normal floating paving, and the paver's travel speed is 0 for a period of time exceeding the set time threshold, it will automatically match the load reduction and anti-fall control sub-mode of the adaptive pressure adjustment mode. When the paver restarts after a material standby, if the ambient temperature, initial screed temperature, asphalt mixture temperature, and paving start-up status simultaneously meet the anti-creep trigger conditions, the automatic matching of the adaptive pressure adjustment mode's loading anti-creep control sub-mode will automatically activate. Hydraulic oil output from the P port of the control valve block will simultaneously supply oil to the rodless chambers of both the left and right hydraulic cylinders via the pilot valve, the P2 port of the lifting valve, the A2 port of the lifting valve, and the loading pressure valve. The pressure in the rodless chambers of the left and right hydraulic cylinders will be electrically proportionally regulated by the loading pressure valve. Based on the target value, the actual pressure in the rodless chambers of the hydraulic cylinders will be controlled in a closed-loop pressure loop to stabilize the actual pressure in the rodless chambers of the left and right hydraulic cylinders at the corresponding target value. During the execution of the loading anti-creep control sub-mode, if the screed bottom plate temperature reaches the set temperature threshold and the structural temperature difference is less than the set value, the loading anti-creep control sub-mode will exit, and the paving floating mode will be automatically matched again.

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