An electro-hydraulic control system and method for a commercial vehicle hydro- launch retarder clutch assembly

Abstract

This invention belongs to the field of commercial vehicle powertrain systems and hydraulic control technology, specifically an electro-hydraulic control system and method for a commercial vehicle hydraulic start-up retarder clutch assembly. It includes a priority distribution valve, an oil inlet circuit for the hydraulic working chamber, a quick-release valve, a bypass unloading valve, a return oil cooling circuit, and an electronic control unit. Under hydraulic start-up conditions, the vehicle's power primarily relies on the hydraulic transmission between the pump impeller, working fluid, and turbine to complete the start-up. The mechanical friction clutch does not participate in the start-up power engagement, thereby avoiding friction plate slippage and improving the smoothness of heavy-load start-up. This invention can simultaneously achieve wear-free hydraulic start-up, high-efficiency mechanical direct drive, and long-term hydraulic retarder braking, while reducing residual oil drag in the hydraulic working chamber, reducing parasitic power loss in the system, and improving the smoothness, economy, and braking safety of the commercial vehicle's transmission system.

Description

Technical Field

[0001] This invention relates to the field of power transmission systems and hydraulic control technology for commercial vehicles, specifically to an electro-hydraulic control system and method for a hydraulic start-up retarder clutch assembly for commercial vehicles. Background Technology

[0002] Currently, heavy-duty commercial vehicle transmission systems are gradually developing towards integration, high efficiency, and smoothness. Hydraulic start-up and deceleration clutch assemblies, integrating hydraulic start-up, mechanical direct drive, and hydraulic deceleration braking, have become an important technical form in commercial vehicle transmission systems. This type of assembly relies on a hydraulic control system to complete the filling and emptying of the hydraulic working chamber, clutch control, deceleration braking, cooling, and switching between different operating conditions. Existing hydraulic start-up and deceleration control systems often use high-pressure circulation, overflow pressure regulation, or rely on rotor centrifugal force for oil discharge in mechanical direct drive or non-hydraulic operating states. This method is prone to insufficient discharge of residual oil from the hydraulic working chamber. When residual oil is agitated between the pump impeller and turbine, it creates drag torque, increases parasitic power loss in the system, and may lead to increased oil temperature and assembly overheating. Simultaneously, this type of system needs to meet both the high-pressure, low-flow oil supply required for clutch servo control and the low-pressure, high-flow oil supply required for filling the hydraulic working chamber, deceleration braking, and cooling. Traditional valve group allocation methods lack sufficient priority allocation and decoupling control for high and low pressure oil circuits. Under heavy-load start-up, mechanical direct drive switching, or continuous slow-speed conditions, flow interference and pressure fluctuations are prone to occur, affecting clutch control accuracy, hydraulic working chamber response speed, and overall vehicle driving safety. Therefore, it is necessary to provide an electro-hydraulic control system and control method for a commercial vehicle hydraulic start-up and slow-speed clutch assembly to achieve reliable switching between hydraulic start-up, mechanical direct drive, and hydraulic slow-speed braking conditions, reduce residual oil drag in the hydraulic working chamber and parasitic power loss in the system, and improve clutch control stability, thermal management capabilities, and overall vehicle transmission efficiency. Summary of the Invention

[0003] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0004] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution:

[0005] An electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly includes a priority distribution valve, a hydraulic working chamber oil inlet circuit, a quick discharge valve, a bypass unloading valve, a return oil cooling circuit, and an electronic control unit.

[0006] The inlet, outlet, and distribution outlet of the priority distribution valve are respectively connected to the main hydraulic pump, the clutch control oil circuit, and the hydraulic working chamber.

[0007] The clutch control oil circuit includes a K0 dry main clutch proportional pressure reducing valve, a K0 dry main clutch actuator cylinder, a K1 wet lock-up clutch control valve, and a K1 wet lock-up clutch actuator cylinder.

[0008] The hydraulic working chamber includes a pump wheel and a turbine. The oil inlet circuit of the hydraulic working chamber includes a retarder oil inlet proportional pressure reducing valve and an oil inlet isolation valve. The oil outlet of the retarder oil inlet proportional pressure reducing valve is connected to the hydraulic working chamber via the oil inlet isolation valve.

[0009] The quick-release valve is connected to the hydraulic working chamber;

[0010] The inlet of the bypass unloading valve is connected to the non-priority distribution outlet downstream of the priority distribution valve. The outlet of the bypass unloading valve is connected to the oil tank or cooling circuit. The bypass unloading valve is not directly connected to the main oil circuit between the outlet of the main hydraulic pump and the inlet of the priority distribution valve.

[0011] In mechanical direct drive mode, the electronic control unit controls the proportional pressure reducing valve of the K0 dry main clutch to supply oil to the actuator cylinder of the K0 dry main clutch, controls the control valve of the K1 wet lock-up clutch to be in a non-working state, controls the oil inlet isolation valve to be closed, controls the quick exhaust valve to be opened, and controls the bypass unloading valve to be opened. At the same time, it maintains the priority oil supply to the clutch control oil circuit through the priority distribution valve.

[0012] As a preferred embodiment of the electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to the present invention, it further includes an oil tank, an oil suction filter, a main oil circuit pressure sensor, and a system main safety relief valve. The oil suction end of the main hydraulic pump is connected to the oil tank through the oil suction filter. The main oil circuit pressure sensor is installed on the main oil circuit, and the system main safety relief valve is connected to the main oil circuit.

[0013] As a preferred embodiment of the electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to the present invention, the oil inlet of the K0 dry main clutch proportional pressure reducing valve is connected to the priority oil outlet of the priority distribution valve, and the oil outlet of the K0 dry main clutch proportional pressure reducing valve is connected to the K0 dry main clutch actuator cylinder; the oil inlet of the K1 wet lock-up clutch control valve is connected to the priority oil outlet of the priority distribution valve, and the oil outlet of the K1 wet lock-up clutch control valve is connected to the K1 wet lock-up clutch actuator cylinder.

[0014] As a preferred embodiment of the electro-hydraulic control system for a commercial vehicle hydraulic start-up retarding clutch assembly described in this invention, the return oil cooling circuit includes a retarder return oil throttle orifice, a back pressure check valve, and a heat exchanger. The return oil side of the hydraulic working chamber is connected to the oil tank via the retarder return oil throttle orifice, the back pressure check valve, and the heat exchanger.

[0015] As a preferred embodiment of the electro-hydraulic control system for a commercial vehicle hydraulic start-up retarding clutch assembly according to the present invention, the heat exchanger has a coolant inlet and a coolant outlet, a coolant outlet temperature sensor is provided at the coolant outlet, and a retarder working chamber outlet oil temperature sensor is provided on the oil outlet side of the hydraulic working chamber.

[0016] As a preferred embodiment of the electro-hydraulic control system for a commercial vehicle hydraulic start-up and retarding clutch assembly described in this invention, the electronic control unit is connected to the main oil circuit pressure sensor, the K0 dry main clutch displacement sensor, the coolant outlet temperature sensor, and the retarder working chamber outlet oil temperature sensor, respectively. It is also connected to the K0 dry main clutch proportional pressure reducing valve, the K1 wet lock-up clutch control valve, the retarder inlet proportional pressure reducing valve, the inlet isolation valve, the quick-release valve, and the bypass unloading valve, respectively. The electronic control unit determines the current operating condition as hydraulic start-up, mechanical direct drive, or hydraulic retarding braking based on the vehicle start signal, retarding request signal, vehicle speed signal, engine speed signal, main oil circuit pressure signal, K0 dry main clutch displacement signal, coolant outlet temperature signal, and hydraulic working chamber outlet oil temperature signal.

[0017] An electro-hydraulic control method for a hydraulic start-up retarder clutch assembly in a commercial vehicle includes the following steps:

[0018] The priority distribution valve prioritizes the supply pressure of oil before the clutch control oil circuit, and after the clutch control oil circuit meets the priority supply conditions, the remaining oil is distributed to the oil inlet circuit of the hydraulic working chamber.

[0019] Determine whether the current operating condition is hydraulic start-up, mechanical direct drive, or hydraulic retarding braking.

[0020] When the current working condition is hydraulic start-up, control K0 dry main clutch not to participate in power engagement, control K1 wet lock-up clutch to be in the unlocked state, control the oil inlet isolation valve to open, control the quick discharge valve to close, control the bypass unloading valve to close, and control the retarder oil inlet proportional pressure reducing valve to supply oil to the hydraulic working chamber.

[0021] When the current working condition is mechanical direct drive, control K0 dry main clutch to engage, control K1 wet lock-up clutch to be in non-working state, control oil inlet isolation valve to close, control quick discharge valve to open, and control the bypass unloading valve located downstream of the distribution oil outlet of the priority distribution valve to open, so that the hydraulic working chamber is drained and the non-priority distribution oil circuit is unloaded at low pressure, while maintaining the priority oil supply of the clutch control oil circuit.

[0022] When the current operating condition is hydraulic deceleration braking, the K0 dry main clutch is kept engaged, the K1 wet lock-up clutch actuator cylinder is activated, so that the turbine is in a restricted rotation state with a speed lower than the preset speed. The oil inlet isolation valve is opened, the quick exhaust valve is closed, the bypass unloading valve is closed, and the output pressure and flow of the retarder oil inlet proportional pressure reducing valve are adjusted according to the deceleration braking requirements.

[0023] As a preferred embodiment of the electro-hydraulic control method for a commercial vehicle hydraulic start-up retarder clutch assembly according to the present invention, the priority oil supply condition is as follows: the priority oil circuit pilot pressure reaches the opening pressure set by the priority distribution valve; when the priority oil circuit pilot pressure is lower than the opening pressure, the oil distributed to the oil inlet circuit of the hydraulic working chamber is restricted or cut off.

[0024] As a preferred embodiment of the electro-hydraulic control method for a commercial vehicle hydraulic start-up retarder clutch assembly described in this invention, under mechanical direct drive conditions, the bypass unloading valve only unloads the non-priority distribution oil path downstream of the distribution oil path of the priority distribution valve, and does not directly unload the main oil path between the main hydraulic pump outlet and the priority distribution valve inlet.

[0025] Under hydraulic retarding braking conditions, when the coolant outlet temperature or the hydraulic working chamber outlet oil temperature is higher than the first preset temperature threshold, the target pressure rise rate and maximum output pressure of the retarder inlet proportional pressure reducing valve are limited; when the coolant outlet temperature or the hydraulic working chamber outlet oil temperature is higher than the second preset temperature threshold, the retarder inlet proportional pressure reducing valve is controlled to reduce the output pressure or stop the oil supply, the inlet isolation valve is controlled to close, and the quick exhaust valve is controlled to open.

[0026] Compared with the prior art, the beneficial effects of this invention are as follows: Under hydraulic starting conditions, the vehicle's power mainly relies on the hydraulic transmission between the pump wheel, working fluid, and turbine to complete the start-up. The mechanical friction clutch does not participate in the starting power engagement, thereby avoiding friction plate slippage and improving the smoothness of heavy-load starting. Under mechanical direct drive conditions, the K0 dry main clutch engages, and the power is directly transmitted to the subsequent transmission system through the K0 dry main clutch. At the same time, the K1 wet lock-up clutch does not participate in the mechanical direct drive power transmission, and the hydraulic working chamber is emptied or no longer undertakes the main transmission function, thereby improving the mechanical transmission efficiency. Under hydraulic deceleration braking conditions, the K0 dry main clutch remains engaged, and the K1 wet lock-up clutch actuator locks the turbine rotation, allowing the turbine to participate in hydraulic deceleration as a stator. The pump wheel agitates the oil to generate fluid resistance and form a deceleration braking torque, thereby providing continuous and wear-free auxiliary braking capability. Therefore, the present invention can take into account wear-free hydraulic starting, high-efficiency mechanical direct drive, and long-term hydraulic slow braking, and can reduce residual oil drag in the hydraulic working chamber, reduce parasitic power loss in the system, and improve the smoothness, economy and braking safety of the commercial vehicle transmission system. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0028] Figure 1 This is a schematic diagram of the electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to the present invention.

[0029] Figure 2 This is a schematic diagram of the oil transmission route of the electro-hydraulic control system of the hydraulic start-up retarder clutch assembly for commercial vehicles under hydraulic start-up conditions.

[0030] Figure 3 This is a schematic diagram of the oil transmission route of the electro-hydraulic control system of the hydraulic start-up retarder clutch assembly for commercial vehicles under mechanical direct drive conditions.

[0031] Figure 4 This is a schematic diagram of the oil transmission path of the electro-hydraulic control system of the hydraulic start-up retarding clutch assembly for commercial vehicles under hydraulic retarding braking conditions.

[0032] In the diagram: 1-Turbine; 2-Pump wheel; 3-Quick exhaust valve; 4-Inlet isolation valve; 5-Retarder return oil throttle orifice; 6-Coolant inlet; 7-Heat exchanger; 8-Coolant outlet; 9-Coolant outlet temperature sensor; 10-Main oil circuit pressure sensor; 11-Electronic control unit; 12-Back pressure check valve; 13-Retarder inlet proportional pressure reducing valve; 14-Bypass unloading valve; 15-Priority distribution valve; 16-Main hydraulic pump; 17-Suction filter; 18-K0 dry main clutch proportional pressure reducing valve; 19-K1 wet lock-up clutch control valve; 20-System main safety relief valve; 21-Priority oil circuit pilot damping orifice; 22-K0 dry main clutch actuator cylinder; 23-K1 wet lock-up clutch actuator cylinder; 24-Oil tank; 25-K0 dry main clutch displacement sensor; 26-Retarder working chamber outlet oil temperature sensor. Detailed Implementation

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0036] Please see Figure 1 An electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly includes a turbine 1, a pump wheel 2, a quick-release valve 3, an oil inlet isolation valve 4, a retarder return oil throttle orifice 5, a coolant inlet 6, a heat exchanger 7, a coolant outlet 8, a coolant outlet temperature sensor 9, a main oil circuit pressure sensor 10, an electronic control unit 11, a back pressure check valve 12, a retarder inlet proportional pressure reducing valve 13, a bypass unloading valve 14, a priority distribution valve 15, a main hydraulic pump 16, an oil suction filter 17, a K0 dry main clutch proportional pressure reducing valve 18, a K1 wet lock-up clutch control valve 19, a system main safety relief valve 20, a priority oil circuit pilot damping orifice 21, a K0 dry main clutch actuator cylinder 22, a K1 wet lock-up clutch actuator cylinder 23, an oil tank 24, a K0 dry main clutch displacement sensor 25, and a retarder working chamber outlet oil temperature sensor 26.

[0037] In this embodiment, the electro-hydraulic control system can be divided into an oil supply and safety protection module, a priority diversion module, a clutch control module, a hydraulic start-up and deceleration control module, a quick discharge and unloading module, a thermal management module, and an electronic control module. Specifically, the oil supply and safety protection module supplies pressurized oil to the system and limits the system's maximum operating pressure; the priority diversion module prioritizes the pre-valve oil supply pressure to the clutch control module; the clutch control module controls the execution status of the K0 dry main clutch and the K1 wet lock-up clutch; the hydraulic start-up and deceleration control module realizes the filling, returning, hydraulic start-up, and hydraulic deceleration of the hydraulic working chamber; the quick discharge and unloading module discharges residual oil and performs low-pressure unloading on non-priority oil circuits when the hydraulic working chamber exits operation; the thermal management module dissipates heat from the system oil and provides temperature feedback signals; and the electronic control module coordinates the control of various valves based on the vehicle's operating status and sensor signals.

[0038] The oil supply and safety protection module includes an oil tank 24, a suction filter 17, a main hydraulic pump 16, a main oil circuit pressure sensor 10, and a system main safety relief valve 20. The suction end of the main hydraulic pump 16 is connected to the oil tank 24 via the suction filter 17, and the outlet end of the main hydraulic pump 16 is connected to the main oil circuit. The main oil circuit pressure sensor 10 is located on the main oil circuit and is used to detect the main oil circuit pressure and send the detected pressure signal to the electronic control unit 11. The system main safety relief valve 20 is connected to the main oil circuit and is used to relieve pressure when the main oil circuit pressure exceeds a preset safety pressure, thereby protecting the valves, actuators, and oil circuits in the hydraulic system.

[0039] The priority distribution module includes a priority distribution valve 15 and a priority oil circuit pilot damping orifice 21. The priority distribution valve 15 is located on the outlet side of the main hydraulic pump 16. The inlet of the priority distribution valve 15 is connected to the main oil circuit, the priority outlet of the priority distribution valve 15 is connected to the clutch control module, and the distribution outlet of the priority distribution valve 15 is connected to the hydraulic start-up retarder control module. The priority oil circuit pilot damping orifice 21 is used to establish the pilot control pressure of the priority distribution valve 15, ensuring that the pressurized oil output from the main hydraulic pump 16 is preferentially supplied to the clutch control module. After meeting the pre-valve oil supply pressure requirements of the clutch control module, the remaining oil is distributed to the hydraulic start-up retarder control module.

[0040] The priority distribution valve 15 is used to prioritize the supply oil pressure to the K0 dry main clutch proportional pressure reducing valve 18 and the K1 wet lock-up clutch control valve 19. When the priority oil circuit pressure of the clutch control module reaches the preset priority oil supply pressure threshold, the priority distribution valve 15 allows the remaining oil to be distributed to the hydraulic start-up retarding control module; when the priority oil circuit pressure of the clutch control module is lower than the preset priority oil supply pressure threshold, the priority distribution valve 15 restricts or cuts off the oil distributed to the hydraulic start-up retarding control module to avoid the retarder inlet oil circuit occupying the flow and causing the clutch control oil circuit to lose pressure.

[0041] It should be noted that the priority oil supply of the clutch control module refers to the priority establishment of oil supply pressure on the oil inlet side of the K0 dry main clutch proportional pressure reducing valve 18 and the K1 wet lock-up clutch control valve 19, and does not mean that the K0 dry main clutch actuator cylinder 22 or the K1 wet lock-up clutch actuator cylinder 23 will operate under all operating conditions. Whether the corresponding actuator operates is controlled by the electronic control unit 11 according to the current operating conditions.

[0042] Specifically, the clutch control module includes a K0 dry main clutch proportional pressure reducing valve 18, a K0 dry main clutch actuator cylinder 22, a K0 dry main clutch displacement sensor 25, a K1 wet lock-up clutch control valve 19, and a K1 wet lock-up clutch actuator cylinder 23. The inlet of the K0 dry main clutch proportional pressure reducing valve 18 is connected to the priority outlet of the priority distribution valve 15, and the outlet of the K0 dry main clutch proportional pressure reducing valve 18 is connected to the K0 dry main clutch actuator cylinder 22. The K0 dry main clutch displacement sensor 25 is used to detect the actuator displacement of the K0 dry main clutch actuator cylinder 22 and feeds the displacement signal back to the electronic control unit 11. The inlet of the K1 wet lock-up clutch control valve 19 is connected to the priority outlet of the priority distribution valve 15, and the outlet of the K1 wet lock-up clutch control valve 19 is connected to the K1 wet lock-up clutch actuator cylinder 23.

[0043] The K0 dry main clutch proportional pressure reducing valve 18 is used to adjust the oil pressure entering the K0 dry main clutch actuator cylinder 22 according to the control command of the electronic control unit 11, so as to control the engagement, disengagement or holding state of the K0 dry main clutch. The K1 wet lock-up clutch control valve 19 is used to control the oil entering the K1 wet lock-up clutch actuator cylinder 23, so as to activate the K1 wet lock-up clutch actuator cylinder 23 under hydraulic deceleration braking conditions, thereby locking the turbine 1 from rotating, so that the turbine 1 participates in hydraulic deceleration as a stationary or nearly stationary stator.

[0044] Specifically, the hydraulic start-up retardation control module includes a retarder inlet proportional pressure reducing valve 13, an inlet isolation valve 4, a pump impeller 2, a turbine 1, and a retarder return oil throttle orifice 5. The inlet end of the retarder inlet proportional pressure reducing valve 13 is connected to the distribution outlet end of the priority distribution valve 15, and the outlet end of the retarder inlet proportional pressure reducing valve 13 is connected to the hydraulic working chamber formed by the pump impeller 2 and the turbine 1 through the inlet isolation valve 4. The retarder return oil throttle orifice 5 is located on the return side of the hydraulic working chamber and is used to throttle and regulate the pressure of the oil discharged from the hydraulic working chamber.

[0045] The retarder inlet proportional pressure reducing valve 13 is used to adjust the oil pressure and flow rate entering the hydraulic working chamber according to the control commands of the electronic control unit 11. The inlet isolation valve 4 is used to open the oil inlet channel of the hydraulic working chamber during hydraulic start-up or hydraulic retarding braking, and to cut off the oil inlet channel of the hydraulic working chamber during mechanical direct drive. The retarder return oil throttle orifice 5 is used to maintain a stable return oil state in the hydraulic working chamber during operation.

[0046] Specifically, the quick discharge unloading module includes a quick discharge valve 3, a bypass unloading valve 14, and a back pressure check valve 12. The quick discharge valve 3 is connected to the hydraulic working chamber and is used to quickly discharge the residual oil in the hydraulic working chamber when the hydraulic working chamber is disengaged. The back pressure check valve 12 is located in the return oil circuit and is used to maintain the minimum back pressure in the return oil circuit and prevent the oil from flowing backward.

[0047] The bypass unloading valve 14 is located downstream of the distribution outlet of the priority distribution valve 15. The inlet of the bypass unloading valve 14 is connected to the non-priority distribution outlet of the priority distribution valve 15, and the outlet of the bypass unloading valve 14 is connected to the oil tank 24 or the cooling circuit. The bypass unloading valve 14 is used to unload the non-priority oil distributed by the priority distribution valve 15 to the hydraulic start-up slow control module when the system is under low load or in a non-hydraulic operating state.

[0048] It should be noted that the unloading channel of the bypass unloading valve 14 is located downstream of the distribution outlet of the priority distribution valve 15, and is not directly connected to the main oil circuit between the outlet of the main hydraulic pump 16 and the inlet of the priority distribution valve 15. When the bypass unloading valve 14 is open, the priority outlet of the priority distribution valve 15 can still supply oil to the K0 dry main clutch proportional pressure reducing valve 18 and the K1 wet lock-up clutch control valve 19, thereby preventing the clutch control oil circuit from losing pressure due to the opening of the bypass unloading valve 14.

[0049] Specifically, the thermal management module includes a heat exchanger 7, a coolant inlet 6, a coolant outlet 8, a coolant outlet temperature sensor 9, and a retarder working chamber outlet oil temperature sensor 26. The heat exchanger 7 is located in the retarder's return oil circuit and has a coolant inlet 6 and a coolant outlet 8. The coolant outlet temperature sensor 9 is located at the coolant outlet 8 and is used to detect the coolant outlet temperature. The retarder working chamber outlet oil temperature sensor 26 is located on the oil outlet side of the hydraulic working chamber and is used to detect the temperature of the oil discharged from the hydraulic working chamber.

[0050] The oil discharged from the hydraulic working chamber flows back to the oil tank 24 through the retarder return throttle orifice 5, the heat exchanger 7, and the back pressure check valve 12. Coolant enters the heat exchanger 7 through the coolant inlet 6 and flows out through the coolant outlet 8 to cool the oil flowing through the heat exchanger 7. The electronic control unit 11 determines the system's thermal load status based on the temperature signals from the coolant outlet temperature sensor 9 and the retarder working chamber outlet oil temperature sensor 26, and coordinates the control of the retarder inlet proportional pressure reducing valve 13, the inlet isolation valve 4, the quick discharge valve 3, and the bypass unloading valve 14.

[0051] Specifically, the electronic control module includes an electronic control unit 11. The electronic control unit 11 is connected to the main oil circuit pressure sensor 10, the coolant outlet temperature sensor 9, the K0 dry main clutch displacement sensor 25, and the retarder working chamber outlet oil temperature sensor 26, respectively. It is also connected to the K0 dry main clutch proportional pressure reducing valve 18, the K1 wet lock-up clutch control valve 19, the retarder inlet proportional pressure reducing valve 13, the inlet isolation valve 4, the quick discharge valve 3, and the bypass unloading valve 14, respectively.

[0052] The electronic control unit 11 determines whether the vehicle is currently in hydraulic start-up mode, mechanical direct drive mode, or hydraulic retarding braking mode based on the vehicle start-up signal, retarding request signal, vehicle speed signal, engine speed signal, main oil circuit pressure signal, K0 dry main clutch displacement signal, coolant outlet temperature signal, and retarder working chamber outlet oil temperature signal, and outputs corresponding control commands according to the determined mode.

[0053] Specifically, the electronic control unit 11 controls the operating status of the inlet isolation valve 4, quick exhaust valve 3, bypass unloading valve 14, retarder inlet proportional pressure reducing valve 13, K0 dry main clutch proportional pressure reducing valve 18, and K1 wet lock-up clutch control valve 19 according to the current operating conditions. The status of the main control valves of the electro-hydraulic control system under different operating conditions is shown in Table 1.

[0054] Table 1: Status of Main Control Valves in Electro-hydraulic Control System under Different Operating Conditions

[0055]

[0056] It should be noted that Table 1 is only used to illustrate the preferred operating states of each major control valve under typical operating conditions in this embodiment, and is not intended to limit the only control method for each valve under all operating states. In actual control, the electronic control unit 11 can correct the opening degree, closing timing, pressure output value, or proportional adjustment amount of the above-mentioned valves based on signals such as vehicle load, vehicle speed, engine speed, main oil circuit pressure, retarding request intensity, coolant outlet temperature, and retarder working chamber outlet oil temperature.

[0057] It should be noted that, in Figures 2 to 4 In the diagram, the thick red solid line represents the main oil circuit that establishes pressure or allows oil supply under the current operating condition. When the thick red solid line extends to the oil inlet side of the control valve, it only indicates that the oil circuit before the control valve has established oil supply pressure, and does not necessarily mean that the control valve outputs pressure to its corresponding actuator. Whether the control valve outputs pressure to the actuator is controlled by the electronic control unit 11 according to the current operating condition. Therefore, under hydraulic starting conditions, although the priority distribution valve 15 prioritizes establishing the oil supply pressure before the valve to the clutch control module, the K0 dry main clutch proportional pressure reducing valve 18 does not output pressure to the K0 dry main clutch actuator cylinder 22, and the K1 wet lock-up clutch control valve 19 does not cause the K1 wet lock-up clutch actuator cylinder 23 to enter the lock-up state.

[0058] like Figure 2 As shown, under hydraulic start-up conditions, the electronic control unit 11 controls the inlet isolation valve 4 to open, the quick discharge valve 3 to close, the bypass unloading valve 14 to close, and controls the retarder inlet proportional pressure reducing valve 13 to adjust the output pressure and flow rate according to start-up requirements. At this time, the oil in the oil tank 24 is filtered by the suction filter 17 and then sucked in and pressurized by the main hydraulic pump 16. The pressurized oil output by the main hydraulic pump 16 enters the priority distribution valve 15.

[0059] In hydraulic start-up mode, the priority distribution valve 15 first establishes oil supply pressure to the pre-valve oil circuit of the clutch control module. When the priority oil circuit pressure of the clutch control module meets the preset priority oil supply conditions, the priority distribution valve 15 distributes the remaining oil to the hydraulic start-up retarding control module. This portion of oil flows from the priority distribution valve 15 to the retarder inlet proportional pressure reducing valve 13. After the pressure and flow rate are regulated by the retarder inlet proportional pressure reducing valve 13, it then enters the hydraulic working chamber formed by the pump impeller 2 and the turbine 1 through the inlet isolation valve 4.

[0060] In hydraulic start-up mode, the electronic control unit 11 controls the proportional pressure reducing valve 18 of the K0 dry main clutch to close or not output pressure, so that the K0 dry main clutch actuator cylinder 22 does not participate in the power engagement process during the start-up phase; at the same time, the electronic control unit 11 controls the K1 wet lock-up clutch control valve 19 to be in the unlocked state, so that the K1 wet lock-up clutch actuator cylinder 23 does not lock the turbine 1. The engine drives the pump wheel 2 to rotate, the pump wheel 2 agitates the oil in the hydraulic working chamber, the oil acts on the turbine 1 and drives the turbine 1 to rotate, the turbine 1 transmits power to the subsequent transmission components, thereby realizing hydraulic start-up of the vehicle without mechanical friction plate slippage.

[0061] After completing the hydraulic transmission in the hydraulic working chamber, the oil flows out from the return oil side of the hydraulic working chamber, enters the return oil circuit after being throttled by the return oil throttle hole 5 of the retarder, and then enters the heat exchanger 7 for heat dissipation. After heat dissipation, the oil flows back to the oil tank 24 through the back pressure check valve 12.

[0062] Applying the technical solution of this embodiment, under hydraulic starting conditions, the K0 dry main clutch does not participate in power engagement, and the K1 wet lock-up clutch does not lock the turbine. The vehicle's power mainly relies on the hydraulic transmission between the pump wheel 2, the working fluid, and the turbine 1 to complete the start-up, thereby avoiding mechanical friction plate slippage during the starting phase, improving the smoothness of starting, and reducing clutch wear.

[0063] like Figure 3 As shown, under mechanical direct drive conditions, the electronic control unit 11 controls the proportional pressure reducing valve 18 of the K0 dry main clutch to supply oil to the actuator cylinder 22 of the K0 dry main clutch, causing the K0 dry main clutch to engage. At this time, the engine power is directly transmitted to the subsequent transmission system via the K0 dry main clutch, realizing the transmission of mechanical direct drive force. Simultaneously, the electronic control unit 11 controls the control valve 19 of the K1 wet lock-up clutch to be in a non-operating state, so that the K1 wet lock-up clutch does not participate in the transmission of mechanical direct drive force.

[0064] Under mechanical direct drive conditions, the electronic control unit 11 controls the oil inlet isolation valve 4 to close, thereby cutting off the oil inlet channel between the retarder oil inlet proportional pressure reducing valve 13 and the hydraulic working chamber, preventing oil from continuing to enter the hydraulic working chamber. At the same time, the electronic control unit 11 controls the quick discharge valve 3 to open, allowing the residual oil in the hydraulic working chamber to be quickly discharged through the quick discharge valve 3 and flow back to the oil tank 24. This causes the hydraulic start-up retarding control module to exit the working state, and the hydraulic working chamber no longer undertakes the main power transmission function, reducing the drag loss caused by residual oil in the hydraulic working chamber.

[0065] In mechanical direct drive mode, the electronic control unit 11 controls the bypass unloading valve 14 to open. At this time, the pressurized oil output from the main hydraulic pump 16 enters the priority distribution valve 15, which prioritizes ensuring the pre-valve oil supply pressure of the oil circuit where the proportional pressure reducing valve 18 of the K0 dry main clutch is located. After meeting the oil supply requirements of the clutch control module, the priority distribution valve 15 distributes the remaining oil to the non-priority distribution oil circuit. This portion of oil flows back to the oil tank 24 or the cooling circuit at low pressure through the bypass unloading valve 14. Through this structure, the pressure of the priority oil supply circuit will not be reduced when the bypass unloading valve 14 is opened, thus ensuring that the K0 dry main clutch remains engaged in mechanical direct drive mode.

[0066] Applying the technical solution of this embodiment, under mechanical direct drive conditions, power is mainly transmitted through the mechanical transmission path corresponding to the K0 dry main clutch, and the hydraulic working chamber no longer bears the main power transmission function. By cutting off the oil inlet with the oil inlet isolation valve 4, discharging residual oil with the quick discharge valve 3, and performing low-pressure unloading on the non-priority oil circuit with the bypass unloading valve 14, hydraulic drag loss and parasitic power loss of the hydraulic system can be reduced, thereby improving mechanical transmission efficiency.

[0067] like Figure 4 As shown, under hydraulic deceleration braking conditions, the electronic control unit 11 controls the proportional pressure reducing valve 18 of the K0 dry main clutch to supply oil to the actuator cylinder 22 of the K0 dry main clutch, keeping the K0 dry main clutch engaged to maintain the transmission relationship between the engine side, the pump wheel 2, and the subsequent transmission system. Simultaneously, the electronic control unit 11 controls the control valve 19 of the K1 wet lock-up clutch to operate, causing the actuator cylinder 23 of the K1 wet lock-up clutch to actuate, locking the turbine 1 from rotation, so that the turbine 1 participates in hydraulic deceleration as a stationary or nearly stationary stator.

[0068] Under hydraulic retarding braking conditions, the electronic control unit 11 controls the inlet isolation valve 4 to open, the quick-release valve 3 to close, and the bypass unloading valve 14 to close. It also adjusts the output pressure and flow rate of the retarder inlet proportional pressure reducing valve 13 according to the retarding braking requirements. The oil in the tank 24, after being filtered by the suction filter 17, is drawn in and pressurized by the main hydraulic pump 16. The pressurized oil output by the main hydraulic pump 16 enters the priority distribution valve 15. After prioritizing the supply pressure to the clutch control module valve, the priority distribution valve 15 distributes the remaining oil to the hydraulic start-up retarding control module. This portion of the oil flows from the priority distribution valve 15 to the retarder inlet proportional pressure reducing valve 13. After being regulated by the retarder inlet proportional pressure reducing valve 13, it then enters the hydraulic working chamber formed by the pump impeller 2 and the turbine 1 via the inlet isolation valve 4.

[0069] The oil entering the hydraulic working chamber circulates between the pump wheel 2 and the turbine 1. The engine side or the wheel reverse drive system drives the pump wheel 2 to rotate. The pump wheel 2 acts as a rotor to agitate the oil in the hydraulic working chamber. The oil impacts the turbine 1, which is locked in rotation by the K1 wet lock-up clutch actuator cylinder 23, thereby generating fluid resistance. This fluid resistance forms a slow braking torque to reduce the engine speed or vehicle speed.

[0070] After operation, the high-temperature oil flows out from the outlet of the hydraulic working chamber, is throttled through the retarder return oil throttle orifice 5, and then enters the return oil circuit, flowing into the heat exchanger 7. After exchanging heat with the coolant in the heat exchanger 7, it flows back to the oil tank 24 via the back pressure check valve 12. Simultaneously, the coolant enters the heat exchanger 7 through the coolant inlet 6, exchanges heat with the flowing high-temperature oil in the heat exchanger 7, and then flows out from the coolant outlet 8. The coolant outlet temperature sensor 9 detects the coolant temperature at the coolant outlet 8, and the retarder working chamber outlet oil temperature sensor 26 detects the oil temperature at the outlet of the hydraulic working chamber, feeding back the corresponding temperature signal to the electronic control unit 11.

[0071] Applying the technical solution of this embodiment, under hydraulic deceleration braking conditions, the K0 dry main clutch remains engaged, and the K1 wet lock-up clutch actuator cylinder 23 locks the turbine 1 from rotating, allowing the turbine 1 to participate in hydraulic deceleration as a stator; the pump wheel 2 agitates the oil and causes the oil to impact the turbine 1, which is restricted in rotation, thereby forming a continuous, wear-free hydraulic deceleration braking torque. After operation, the high-temperature oil exchanges heat with the coolant through the heat exchanger 7, thereby improving the thermal management capability under continuous deceleration conditions.

[0072] When the main oil circuit pressure sensor 10 detects that the main oil circuit pressure is lower than the preset pressure threshold, the priority distribution valve 15 prioritizes the supply pressure of the oil circuit where the K0 dry main clutch proportional pressure reducing valve 18 and the K1 wet lock-up clutch control valve 19 are located, and limits the oil flow distributed to the hydraulic start-up retarder control module, so as to reduce the flow interference of the retarder inlet oil circuit or cooling oil circuit to the clutch control oil circuit.

[0073] When the coolant outlet temperature sensor 9 detects that the coolant outlet temperature is higher than the first preset temperature threshold, or the retarder working chamber outlet oil temperature sensor 26 detects that the hydraulic working chamber outlet oil temperature is higher than the first preset oil temperature threshold, the electronic control unit 11 limits the target pressure rise rate and maximum output pressure of the retarder inlet proportional pressure reducing valve 13 to limit the retarding braking torque generated by the hydraulic working chamber, while maintaining the oil circulation between the hydraulic working chamber and the heat exchanger 7 to avoid a rapid increase in the local temperature of the hydraulic working chamber.

[0074] When the coolant outlet temperature exceeds the second preset temperature threshold, or the oil temperature at the outlet of the hydraulic working chamber exceeds the second preset oil temperature threshold, the electronic control unit 11 determines that the system has entered an overheat protection state. At this time, the electronic control unit 11 controls the retarder inlet proportional pressure reducing valve 13 to reduce the output pressure or stop supplying oil to the hydraulic working chamber, controls the inlet isolation valve 4 to close, and controls the quick discharge valve 3 to open, so that the high-temperature oil in the hydraulic working chamber can be quickly discharged; at the same time, the electronic control unit 11 controls the bypass unloading valve 14 to open, so that the non-priority distribution oil circuit enters a low-pressure unloading state, and sends a signal to the vehicle control system requesting a reduction in retarding demand, downshifting, or mechanical braking takeover.

[0075] Through the above-mentioned graded thermal protection control, the system prioritizes limiting the slow braking torque and maintaining oil circulation for heat dissipation when the thermal load increases slightly. When the overheating is severe, the system exits the hydraulic slow braking and quickly empties the hydraulic working chamber, thereby avoiding insufficient local heat dissipation in the hydraulic working chamber caused by simply reducing the oil inlet flow.

[0076] In another specific embodiment proposed in this application, the bypass unloading valve 14 can be proportionally controlled or switched on / off controlled according to system pressure, oil temperature, or vehicle operating conditions; the quick-release valve 3 can be configured as an electro-hydraulic control valve, a hydraulic control valve, or an electro-hydraulic composite control valve; the oil inlet isolation valve 4 can be separately arranged from the retarder oil inlet proportional pressure reducing valve 13, or it can be integrated into an integral valve group. The above-mentioned changes in structural form do not affect the technical concept of achieving multi-condition coordinated control through priority diversion, oil inlet isolation, quick-release anti-drag, and bypass unloading.

[0077] In another specific embodiment proposed in this application, the electronic control unit 11 can also determine the retardation demand based on the vehicle brake pedal signal, the retarder handle signal, the vehicle controller signal, the engine torque signal, the transmission gear signal or the vehicle speed signal, and adjust the output pressure and flow rate of the retarder oil inlet proportional pressure reducing valve 13 according to the retardation demand to achieve hydraulic retardation braking of different intensities.

[0078] According to another specific embodiment of this application, a commercial vehicle is also provided, which has the electro-hydraulic control system of the aforementioned commercial vehicle hydraulic start-up retarder clutch assembly. By installing the aforementioned electro-hydraulic control system on the commercial vehicle, the smoothness of vehicle start-up under hydraulic start-up conditions can be improved, hydraulic drag and hydraulic system power loss can be reduced under mechanical direct drive conditions, and the retarder braking stability and thermal management capability can be improved under hydraulic retarder braking conditions, thereby improving the efficiency, reliability and driving safety of the commercial vehicle's transmission system.

[0079] As can be seen from the above description, the electro-hydraulic control system of the commercial vehicle hydraulic start-up retarder clutch assembly in the above embodiments has at least the following beneficial effects:

[0080] 1) Improve the smoothness of hydraulic start-up: Under hydraulic start-up conditions, the K0 dry main clutch does not participate in power engagement, and the K1 wet lock-up clutch does not lock the turbine. The vehicle's power mainly relies on the hydraulic transmission between the pump wheel 2, the working fluid, and the turbine 1 to complete the start-up, thereby avoiding slippage of the mechanical friction plates.

[0081] 2) Improve the efficiency of mechanical direct drive transmission: Under mechanical direct drive conditions, the K0 dry main clutch is engaged, and the power is directly transmitted to the subsequent transmission system through the K0 dry main clutch. At the same time, the hydraulic working chamber is emptied or no longer undertakes the main transmission function, thereby reducing hydraulic drag loss.

[0082] 3) Reduce system parasitic power loss: By setting the bypass unloading valve 14 downstream of the distribution oil outlet of the priority distribution valve 15, the non-priority distribution oil circuit can enter the low-pressure unloading state under low load or non-hydraulic working conditions, while avoiding affecting the oil supply of the priority oil supply circuit to the clutch control module.

[0083] 4) Improve the stability of hydraulic retarding braking: Under the hydraulic retarding braking condition, the K0 dry main clutch remains engaged, and the K1 wet lock-up clutch actuator cylinder 23 locks the turbine 1 to rotate, so that the turbine 1 participates in hydraulic retarding as a stator, thereby forming a stable hydraulic retarding braking torque.

[0084] 5) Improve thermal management capabilities: The system thermal load is monitored and adjusted in real time through the heat exchanger 7, coolant outlet temperature sensor 9 and retarder working chamber outlet oil temperature sensor 26, and the reliability under continuous retarding conditions is improved through graded thermal protection control.

[0085] 6) Reduce oil circuit interference: Prioritize the oil supply pressure before the clutch control module by using priority distribution valve 15, and after meeting the oil supply requirements of the clutch control module, distribute the remaining flow to the hydraulic start-up retardation control module, so that priority flow diversion and functional decoupling are achieved between the clutch control oil circuit and the hydraulic start-up retardation oil circuit.

[0086] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly, characterized in that, It includes a priority distribution valve, a hydraulic working chamber inlet oil passage, a quick discharge valve, a bypass unloading valve, a return oil cooling passage, and an electronic control unit; The inlet, outlet, and distribution outlet of the priority distribution valve are respectively connected to the main hydraulic pump, the clutch control oil circuit, and the hydraulic working chamber. The clutch control oil circuit includes a K0 dry main clutch proportional pressure reducing valve, a K0 dry main clutch actuator cylinder, a K1 wet lock-up clutch control valve, and a K1 wet lock-up clutch actuator cylinder. The hydraulic working chamber includes a pump wheel and a turbine. The oil inlet circuit of the hydraulic working chamber includes a retarder oil inlet proportional pressure reducing valve and an oil inlet isolation valve. The oil outlet of the retarder oil inlet proportional pressure reducing valve is connected to the hydraulic working chamber via the oil inlet isolation valve. The quick-release valve is connected to the hydraulic working chamber; The inlet of the bypass unloading valve is connected to the non-priority distribution outlet downstream of the priority distribution valve. The outlet of the bypass unloading valve is connected to the oil tank or cooling circuit. The bypass unloading valve is not directly connected to the main oil circuit between the outlet of the main hydraulic pump and the inlet of the priority distribution valve. In mechanical direct drive mode, the electronic control unit controls the proportional pressure reducing valve of the K0 dry main clutch to supply oil to the actuator cylinder of the K0 dry main clutch, controls the control valve of the K1 wet lock-up clutch to be in a non-working state, controls the oil inlet isolation valve to be closed, controls the quick exhaust valve to be opened, and controls the bypass unloading valve to be opened. At the same time, it maintains the priority oil supply to the clutch control oil circuit through the priority distribution valve.

2. The electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to claim 1, characterized in that, It also includes an oil tank, an oil suction filter, a main oil circuit pressure sensor, and a system main safety relief valve. The oil suction end of the main hydraulic pump is connected to the oil tank through the oil suction filter. The main oil circuit pressure sensor is installed on the main oil circuit, and the system main safety relief valve is connected to the main oil circuit.

3. The electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to claim 1, characterized in that, The inlet of the K0 dry main clutch proportional pressure reducing valve is connected to the priority outlet of the priority distribution valve, and the outlet of the K0 dry main clutch proportional pressure reducing valve is connected to the K0 dry main clutch actuator cylinder; the inlet of the K1 wet lock-up clutch control valve is connected to the priority outlet of the priority distribution valve, and the outlet of the K1 wet lock-up clutch control valve is connected to the K1 wet lock-up clutch actuator cylinder.

4. The electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to claim 1, characterized in that, The return oil cooling circuit includes a retarder return oil throttle orifice, a back pressure check valve, and a heat exchanger. The return oil side of the hydraulic working chamber is connected to the oil tank via the retarder return oil throttle orifice, the back pressure check valve, and the heat exchanger.

5. The electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to claim 4, characterized in that, The heat exchanger has a coolant inlet and a coolant outlet. A coolant outlet temperature sensor is installed at the coolant outlet, and a retarder working chamber outlet oil temperature sensor is installed on the oil outlet side of the hydraulic working chamber.

6. The electro-hydraulic control system for a commercial vehicle hydraulic start-up retarder clutch assembly according to claim 1, characterized in that, The electronic control unit is connected to the main oil circuit pressure sensor, the K0 dry main clutch displacement sensor, the coolant outlet temperature sensor, and the retarder working chamber outlet oil temperature sensor, respectively. It is also connected to the K0 dry main clutch proportional pressure reducing valve, the K1 wet lock-up clutch control valve, the retarder inlet proportional pressure reducing valve, the inlet isolation valve, the quick discharge valve, and the bypass unloading valve, respectively. The electronic control unit determines the current operating condition as hydraulic start-up, mechanical direct drive, or hydraulic retarding braking based on the vehicle start signal, retarding request signal, vehicle speed signal, engine speed signal, main oil circuit pressure signal, K0 dry main clutch displacement signal, coolant outlet temperature signal, and hydraulic working chamber outlet oil temperature signal.

7. A method for electro-hydraulic control of a commercial vehicle hydraulic start-up retarder clutch assembly, applied to the electro-hydraulic control system of the commercial vehicle hydraulic start-up retarder clutch assembly as described in any one of claims 1-6, characterized in that, Includes the following steps: The priority distribution valve prioritizes the supply pressure of oil before the clutch control oil circuit, and after the clutch control oil circuit meets the priority supply conditions, the remaining oil is distributed to the oil inlet circuit of the hydraulic working chamber. Determine whether the current operating condition is hydraulic start-up, mechanical direct drive, or hydraulic retarding braking. When the current working condition is hydraulic start-up, control K0 dry main clutch not to participate in power engagement, control K1 wet lock-up clutch to be in the unlocked state, control the oil inlet isolation valve to open, control the quick discharge valve to close, control the bypass unloading valve to close, and control the retarder oil inlet proportional pressure reducing valve to supply oil to the hydraulic working chamber. When the current working condition is mechanical direct drive, control K0 dry main clutch to engage, control K1 wet lock-up clutch to be in non-working state, control oil inlet isolation valve to close, control quick discharge valve to open, and control the bypass unloading valve located downstream of the distribution oil outlet of the priority distribution valve to open, so that the hydraulic working chamber is drained and the non-priority distribution oil circuit is unloaded at low pressure, while maintaining the priority oil supply of the clutch control oil circuit. When the current operating condition is hydraulic deceleration braking, the K0 dry main clutch is kept engaged, the K1 wet lock-up clutch actuator cylinder is activated, so that the turbine is in a restricted rotation state with a speed lower than the preset speed. The oil inlet isolation valve is opened, the quick exhaust valve is closed, the bypass unloading valve is closed, and the output pressure and flow of the retarder oil inlet proportional pressure reducing valve are adjusted according to the deceleration braking requirements.

8. The electro-hydraulic control method for a commercial vehicle hydraulic start-up retarder clutch assembly according to claim 7, characterized in that, The priority oil supply condition is as follows: the priority oil circuit pilot pressure reaches the opening pressure set by the priority distribution valve; when the priority oil circuit pilot pressure is lower than the opening pressure, the oil supplied to the oil inlet circuit of the hydraulic working chamber is restricted or cut off.

9. The electro-hydraulic control method for a commercial vehicle hydraulic start-up retarder clutch assembly according to claim 7, characterized in that, Under mechanical direct drive conditions, the bypass unloading valve only unloads the non-priority distribution oil passage downstream of the distribution oil outlet of the priority distribution valve, and does not directly unload the main oil passage between the oil outlet of the main hydraulic pump and the oil inlet of the priority distribution valve. Under hydraulic retarding braking conditions, when the coolant outlet temperature or the hydraulic working chamber outlet oil temperature is higher than the first preset temperature threshold, the target pressure rise rate and maximum output pressure of the retarder inlet proportional pressure reducing valve are limited; when the coolant outlet temperature or the hydraulic working chamber outlet oil temperature is higher than the second preset temperature threshold, the retarder inlet proportional pressure reducing valve is controlled to reduce the output pressure or stop the oil supply, the inlet isolation valve is controlled to close, and the quick exhaust valve is controlled to open.

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