Transmission hydraulic system pressure control device and method and vehicle

Abstract

The invention discloses a transmission hydraulic system pressure control device and method and a vehicle. According to the device, an electric pump and a mechanical pump are arranged between a hydraulic oil tank and a main oil way in a series connection mode; an oil outlet of the mechanical pump is connected with the main oil way through a first oil way; the pressure control module comprises a pilot valve, a first mechanical slide valve, a second mechanical slide valve and a control unit; the control unit controls the electric pump to start or stop running according to the system demand pressure; the pilot valve is used for controlling the first mechanical slide valve and / or the second mechanical slide valve to participate in adjusting the main oil way pressure according to the system demand pressure. According to the pressure control device for the transmission hydraulic system, the electric pump and the mechanical pump are connected in series, and the pilot valve is matched with the two mechanical slide valves, so that the required power of the electric pump is reduced, the required pressure of the hydraulic system under different working conditions is controlled, the pressure adjusting precision is high, and the energy consumption of the hydraulic system is reduced; and the system economy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission hydraulic system design, and in particular to a transmission hydraulic system pressure control device, method and vehicle. Background Art

[0002] The transmission hydraulic system is a system that achieves automatic shifting by regulating the oil pressure generated by the oil pump to stabilize it at an appropriate main oil pressure level and controlling the relevant oil circuits accordingly. The hydraulic control system includes the main oil supply circuit, the pressure control signal module, the clutch and shift control module, and the cooling and lubrication control module. These components work together to ensure that the transmission can operate efficiently and smoothly under different working conditions.

[0003] In the prior art, the pressure control module of the main oil circuit pressure usually adopts the following two control methods: adopting a solenoid valve pressure control valve for pressure control, and the main oil circuit pressure is related to the solenoid valve current; adopting a solenoid valve plus a mechanical valve control method for pressure control, wherein the solenoid valve is designed in the form of a pilot valve, and the main oil circuit pressure is controlled by controlling the pressure of the mechanical valve. For the above two main oil circuit pressure control methods, there are advantages and disadvantages in control. In the first control method, the number of valves is small and the cost is low, but the control accuracy requirements of the solenoid valve are high; in the second control method, the number of valves is more, but the pressure distributed on each valve is smaller, and the control accuracy requirements of the solenoid valve are not very high. At present, a structure in which a pilot valve controls a mechanical valve is often used to control the main oil circuit pressure, and the oil pressure control effect is poor.

[0004] In the existing transmission hydraulic system design, there are both control flow requirements for clutches, shifting mechanisms, and cooling and lubrication flow requirements. Therefore, the existing transmission hydraulic control system mostly uses two oil pumps to meet the cooling and lubrication flow requirements under increasingly high speeds. For the design of the oil pump, especially the oil pump in the hydraulic system of the hybrid transmission, a mechanical pump plus an electric pump is usually used. When the engine is not working, an electric pump is used to meet the cooling and lubrication needs of various components, which puts forward certain requirements on the power of the electric pump, resulting in an increase in the power required for the overall hydraulic system and an increase in system energy consumption. Summary of the invention

[0005] The present invention provides a transmission hydraulic system pressure control device, method and vehicle to solve the problems of poor oil pressure control effect and high energy consumption of electric pump in existing transmission hydraulic system design schemes, thereby reducing the energy consumption of the hydraulic system.

[0006] According to one aspect of the present invention, a transmission hydraulic system pressure control device is provided, comprising: an electric pump, a mechanical pump, a main oil circuit, a cooling and lubrication control module and a pressure control module; the electric pump and the mechanical pump are arranged in series between a hydraulic oil tank and the main oil circuit, and the electric pump is used to amplify the oil pressure at the oil outlet of the mechanical pump; the oil outlet of the mechanical pump is connected to the main oil circuit via a first oil circuit, the first oil circuit is provided with a first non-return valve, the oil inlet of the first non-return valve is connected to the oil inlet of the electric pump, and the oil outlet of the first non-return valve is connected to the oil outlet of the electric pump and the main oil circuit respectively; the pressure control module comprises a pilot valve, a first A mechanical slide valve, a second mechanical slide valve and a control unit; the control unit is used to control the start or stop operation of the electric pump according to the system demand pressure; the first mechanical slide valve is arranged between the oil outlet of the electric pump and the cooling and lubrication control module; the second mechanical slide valve is arranged between the oil outlet of the mechanical pump and the cooling and lubrication control module; the oil inlet of the pilot valve is connected to the main oil circuit, and the oil outlet of the pilot valve is respectively connected to the spring side control port of the first mechanical slide valve and the spring side control port of the second mechanical slide valve through the pilot oil circuit, and the pilot valve is used to control the first mechanical slide valve and / or the second mechanical slide valve according to the system demand pressure to participate in regulating the main oil circuit pressure.

[0007] Optionally, the first spring preload force of the first mechanical slide valve is greater than the second spring preload force of the second mechanical slide valve, and the lower limit value of the opening pressure of the first mechanical slide valve is less than the upper limit value of the regulation pressure of the second mechanical slide valve, and the upper limit value of the regulation pressure is less than the first system demand pressure when the electric pump is started.

[0008] Optionally, the control port on the spring opposite side of the first mechanical slide valve is connected to the main oil circuit, and the control port on the spring opposite side of the second mechanical slide valve is connected to the main oil circuit; when the pressure in the main oil circuit is less than the preload force of the first spring, the first mechanical slide valve does not participate in regulating the pressure in the main oil circuit; when the system demand pressure is greater than the upper limit value of the control pressure of the second mechanical slide valve and the electric pump stops running, the pressure in the main oil circuit is maintained at the upper limit value of the control pressure, and the first mechanical slide valve does not participate in regulating the pressure in the main oil circuit.

[0009] Optionally, the oil outlet of the electric pump is connected to the control port on the opposite side of the spring of the first mechanical slide valve; when the system demand pressure is greater than the upper limit value of the regulation pressure of the second mechanical slide valve and the electric pump starts running, the first mechanical slide valve and the second mechanical slide valve simultaneously participate in regulating the main oil circuit pressure.

[0010] Optionally, the transmission hydraulic system pressure control device also includes a second oil circuit and a second one-way valve; the second one-way valve is arranged in the second oil circuit, the oil inlet of the second one-way valve is connected to the oil inlet of the mechanical pump via the second oil circuit, and the oil outlet of the second one-way valve is respectively connected to the oil outlet of the mechanical pump and the oil inlet of the electric pump.

[0011] Optionally, the transmission hydraulic system pressure control device further includes: a damping accumulator, which is arranged in parallel with the pilot oil circuit, and the damping accumulator is used to stabilize the pilot pressure output by the pilot valve.

[0012] Optionally, the pilot valve is a normally open electromagnetic proportional valve; the pilot pressure output by the pilot valve is negatively correlated with the control current of the pilot valve.

[0013] Optionally, the rotation speed of the mechanical pump is positively correlated with the engine rotation speed.

[0014] According to another aspect of the present invention, a transmission hydraulic system pressure control method is provided, which is implemented based on the above-mentioned transmission hydraulic system pressure control device. The transmission hydraulic system pressure control device includes an electric pump and a mechanical pump connected in series, and a first mechanical slide valve and a second mechanical slide valve controlled by the same pilot valve. The method includes: controlling the electric pump to start or stop running according to the system demand pressure; controlling the first mechanical slide valve and / or the second mechanical slide valve to participate in regulating the main oil circuit pressure according to the system demand pressure.

[0015] According to another aspect of the present invention, a vehicle is provided, comprising: a transmission, and the above-mentioned transmission hydraulic system pressure control device.

[0016] The technical solution of the embodiment of the present invention is to set an electric pump and a mechanical pump connected in series, control the electric pump to start or stop running according to the system demand pressure, and amplify the oil pressure at the oil outlet of the mechanical pump by the electric pump. At the same time, a pilot valve, a first mechanical slide valve, a second mechanical slide valve and a control unit are set in the pressure control module. The pilot valve controls the first mechanical slide valve and / or the second mechanical slide valve to participate in regulating the main oil circuit pressure according to the system demand pressure, which solves the problems of poor oil pressure control effect and high energy consumption of the electric pump in the existing transmission hydraulic system design, reduces the power requirement of the electric pump, can reduce the energy consumption of the hydraulic system, and improves the economy of the system. Through the control method of a pilot valve with two mechanical valves, the pressure regulation strategy under different working conditions can be adaptively adjusted to improve the pressure regulation accuracy.

[0017] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic structural diagram of a transmission hydraulic system pressure control device provided by an embodiment of the present invention;

[0020] Figure 2 A schematic structural diagram of another transmission hydraulic system pressure control device provided by an embodiment of the present invention;

[0021] Figure 3 The present invention provides a flow chart of a transmission hydraulic system pressure control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] Figure 1 This is a schematic structural diagram of a transmission hydraulic system pressure control device provided in an embodiment of the present invention. This embodiment is applicable to application scenarios in which two oil pumps are used to control the hydraulic system process.

[0025] See also Figure 1The transmission hydraulic system pressure control device of the present application includes: an electric pump 1, a mechanical pump 2, a main oil circuit 101, a cooling and lubrication control module 102 and a pressure control module 3. The main oil circuit 101 is connected to a clutch and shift control module 103, and the cooling and lubrication control module 102 is used to output oil based on the cooling and lubrication requirements of the transmission or the vehicle. The clutch and shift control module 103 is used to output oil based on the clutch and shift pressure requirements.

[0026] See also Figure 1 The electric pump 1 and the mechanical pump 2 of the present application are arranged in series connection between the hydraulic oil tank 4 and the main oil circuit 101; the oil outlet of the mechanical pump 2 is connected to the main oil circuit 101 via the first oil circuit 104, and the first oil circuit 104 is provided with a first check valve 201, the oil inlet of the first check valve 201 is connected to the oil inlet of the electric pump 1, and the oil outlet of the first check valve 201 is connected to the oil outlet of the electric pump 1 and the main oil circuit 101 respectively. When both the mechanical pump 2 and the electric pump 1 are not started, the oil flows from the hydraulic oil tank 4 through the oil inlet of the mechanical pump 2, the oil outlet of the mechanical pump 2 and the first oil circuit 104, and flows into the main oil circuit 101; when the mechanical pump 2 is started and the electric pump 1 is not started, the oil flows from the hydraulic oil tank 4 through the oil inlet of the mechanical pump 2, the oil outlet of the mechanical pump 2 and the first oil circuit 104, and flows into the main oil circuit 101; when the mechanical pump 2 and the electric pump 1 are both started and run, the oil flows from the hydraulic oil tank 4 through the oil inlet of the mechanical pump 2, the oil outlet of the mechanical pump 2, the oil inlet of the electric pump 1 and the oil outlet of the electric pump 1, and flows into the main oil circuit 101. The electric pump 1 is used to amplify the oil pressure at the oil outlet of the mechanical pump 2.

[0027] See also Figure 1 , the pressure control module 3 of the present application includes a pilot valve 301, a first mechanical slide valve 302, a second mechanical slide valve 303 and a control unit 304. Among them, the pilot valve 301 can be understood as a control mechanism for controlling the first mechanical slide valve 302 and the second mechanical slide valve 303. The control unit can be understood as a transmission hydraulic system controller, which is used to control the electric pump 1 to start or stop running according to the system demand pressure. In this embodiment, the system demand pressure is the demand pressure of the main oil circuit 101. Optionally, the system demand pressure can be determined according to the pressure required by the clutch and the shifting mechanism. Specifically, the electric pump 1 starts running when the system demand pressure is high (for example, higher than the pressure regulating capacity of the second mechanical slide valve 303), and the system demand pressure can be judged by the engine speed. The clutch pressure required for the engine speed to increase is higher.

[0028] See also Figure 1As shown, the first mechanical slide valve 302 is arranged between the oil outlet of the electric pump 1 and the cooling and lubrication control module 102; the second mechanical slide valve 303 is arranged between the oil outlet of the mechanical pump 2 and the cooling and lubrication control module 102; the oil inlet of the pilot valve 301 is connected to the main oil circuit 101, and the oil outlet of the pilot valve 301 is connected to the spring side control port A1 of the first mechanical slide valve 302 and the spring side control port B1 of the second mechanical slide valve 303 through the pilot oil circuit 106, respectively. The pilot valve 301 is used to control the first mechanical slide valve 302 and / or the second mechanical slide valve 303 to participate in regulating the main oil circuit pressure according to the system demand pressure. In this embodiment, the pilot pressure applied to the spring side control port A1 of the first mechanical slide valve 302 and the spring side control port B1 of the second mechanical slide valve 303 can be adjusted by controlling the opening of the pilot valve 301. The pilot pressure is in the same direction as the spring preload force and is used to push the mechanical slide valve to move to the left.

[0029] In this embodiment, the second mechanical slide valve 303 is used to perform pressure regulation within a smaller pressure regulation range, and the first mechanical slide valve 302 is used to participate in pressure regulation when the pressure regulation capability of the second mechanical slide valve 303 is insufficient.

[0030] Specifically, during the operation of the transmission hydraulic system, the control unit identifies the system demand pressure through the engine speed. When the system demand pressure is relatively large (for example, higher than the pressure regulating capacity of the second mechanical slide valve 303), the electric pump 1 is controlled to start running, and the oil pressure at the oil outlet of the mechanical pump 2 is amplified by the electric pump 1. At the same time, a pilot valve 301, a first mechanical slide valve 302 and a second mechanical slide valve 303 are set in the pressure control module 3. When the system demand pressure is relatively small (for example, lower than the pressure regulating capacity of the second mechanical slide valve 303), the pilot valve 301 controls the second mechanical slide valve 303 to participate in the regulation. The main oil circuit pressure is controlled; when the system demand pressure is large (for example, higher than the pressure regulating capacity of the second mechanical slide valve 303), the first mechanical slide valve 302 and the second mechanical slide valve 303 are controlled to jointly participate in regulating the main oil circuit pressure, which solves the problems of poor oil pressure control effect and high energy consumption of the electric pump 1 in the existing transmission hydraulic system design, reduces the power requirement of the electric pump 1, can reduce the energy consumption of the hydraulic system, and improve the economy of the system. Through the control method of a pilot valve 301 with two mechanical valves, the pressure regulation strategy under different working conditions can be adaptively adjusted to improve the pressure regulation accuracy.

[0031] Optionally, the first spring preload force of the first mechanical slide valve 302 is greater than the second spring preload force of the second mechanical slide valve 303, and the lower limit value of the opening pressure of the first mechanical slide valve 302 is less than the upper limit value of the regulation pressure of the second mechanical slide valve 303, and the upper limit value of the regulation pressure is less than the first system demand pressure when the electric pump 1 is started.

[0032] Among them, the first spring preload can be understood as the maximum force applied by the spring to the first mechanical slide valve 302, and the direction of this force is the same as the pilot pressure; the second spring preload can be understood as the maximum force applied by the spring to the second mechanical slide valve 303, and the direction of this force is the same as the pilot pressure; the lower limit value of the opening pressure of the first mechanical slide valve 302 can be understood as the minimum force for moving the first mechanical slide valve 302 to the on state, and this force is used to overcome the first spring preload and the pilot pressure; the upper limit value of the control pressure of the second mechanical slide valve 303 can be understood as the maximum force of the second mechanical slide valve 303 in the maximum on state, and this force is used to overcome the second spring preload and the pilot pressure.

[0033] See also Figure 1 As shown, a spring and a spring-side control port A1 are provided on the right side of the first mechanical slide valve 302, and a spring-opposite-side control port A2 is provided on the left side of the first mechanical slide valve 302; a spring and a spring-side control port B1 are provided on the right side of the second mechanical slide valve 303, and a spring-opposite-side control port B2 is provided on the left side of the second mechanical slide valve 303. The spring-opposite-side control port A2 of the first mechanical slide valve 302 is connected to the main oil circuit 101, and the spring-opposite-side control port B2 of the second mechanical slide valve 303 is connected to the main oil circuit 101. When the first mechanical slide valve 302 participates in pressure regulation, the sum of the first spring preload and the pilot pressure applied to the spring-side control port A1 and the pressure applied to the spring-opposite-side control port A2 of the first mechanical slide valve 302 (i.e., the main oil circuit pressure) are balanced with each other. When the second mechanical slide valve 303 participates in pressure regulation, the sum of the second spring preload and the pilot pressure applied to the spring side control port B1 is balanced with the pressure (ie, the main oil circuit pressure) applied to the spring opposite side control port B2 of the second mechanical slide valve 303 .

[0034] See also Figure 1 As shown, when the main oil circuit pressure is less than the first spring preload, the first mechanical slide valve 302 does not participate in regulating the main oil circuit pressure; when the system demand pressure is greater than the upper limit value of the control pressure of the second mechanical slide valve 303 and the electric pump 1 stops running, the main oil circuit pressure is maintained at the upper limit value of the control pressure, and the first mechanical slide valve 302 does not participate in regulating the main oil circuit pressure.

[0035] Specifically, in the initial state, there is no oil in the main oil circuit 101, the main oil circuit pressure is equal to 0, and all hydraulic components are in the position shown in the figure. When the mechanical pump 2 starts running and the electric pump 1 is not started, the oil in the hydraulic oil tank 4 first flows through the oil suction filter and is transported to the first oil circuit 104 through the mechanical pump 2. When the mechanical pump 2 just starts to work, the second mechanical slide valve 303 is in the position shown in the figure under the action of the right spring force. The initial oil pressure of the first oil circuit 104 is relatively low. As the working time of the mechanical pump 2 passes, the oil enters the main oil circuit 101. After the oil pressure increases and enters the main oil circuit 101, the main oil circuit pressure is still relatively low and does not meet the system demand pressure. At this time, the main oil circuit pressure acts on the spring opposite control port A2 of the first mechanical slide valve 302 and the spring opposite control port B2 of the second mechanical slide valve 303 (such as Figure 1 The first mechanical slide valve 302 and the second mechanical slide valve 303 are on the dotted line on the left side), overcoming the spring force of the mechanical valve core (i.e., the first spring preload force and the second spring preload force), thereby moving the valve core until the valve core is opened. At this time, by controlling the electromagnetic force of the pilot valve 301, the flow rate from the main oil circuit 101 to the pilot oil circuit 106 can be adjusted, thereby changing the pilot pressure acting on the spring side control port A1 of the first mechanical slide valve 302 and the spring side control port B1 of the second mechanical slide valve 303 (such as Figure 1 The main oil circuit pressure can be further adjusted by the dashed line on the right side of the first mechanical slide valve 302 and the second mechanical slide valve 303 in the figure. At this time, the main oil circuit pressure is equal to the sum of the pilot pressure output by the pilot valve 301 and the spring preload force, thereby realizing the main oil circuit pressure control. When the main oil circuit pressure is relatively low, the pressure on the left side of the first mechanical slide valve 302 is less than the spring force on the right side, which is even less than the sum of the spring force and the hydraulic pressure controlled by the pilot valve 301. Therefore, the first mechanical slide valve 302 is always in the state shown in the figure and cannot participate in the main oil circuit pressure regulation. Therefore, when regulating the pressure in a smaller range, only the second mechanical slide valve 303 participates in the regulation. When the system demand pressure is high, such as reaching the upper limit value of the control pressure that can be controlled by the second mechanical slide valve 303, the pressure that can be controlled by the pilot valve 301 is the maximum, and the liquid pressure acting on the first mechanical slide valve 302 is also the maximum. At this time, the main oil circuit pressure is still less than the sum of the first spring preload and the pilot pressure provided by the pilot valve 301, and the first mechanical slide valve 302 is still closed. The maximum main oil circuit pressure can only be maintained at the upper limit value of the control pressure of the second mechanical slide valve 303, and the main oil circuit pressure cannot continue to increase. Therefore, higher pressure regulation is achieved by controlling the electric pump to meet the use needs of the hydraulic system.

[0036] See also Figure 1 As shown, the oil outlet of the electric pump 1 is connected to the control port A2 on the spring opposite side of the first mechanical slide valve 302; when the system demand pressure is greater than the upper limit value of the control pressure of the second mechanical slide valve 303 and the electric pump 1 starts running, the first mechanical slide valve 302 and the second mechanical slide valve 303 simultaneously participate in regulating the main oil circuit pressure.

[0037] Specifically, if the system demand pressure exceeds the upper limit of the control pressure that can be provided by the second mechanical slide valve 303, the control unit controls the electric pump 1 to start operation. At this time, the oil in the hydraulic oil tank 4 flows to the mechanical pump 2 through the oil suction filter, flows to the oil inlet of the electric pump 1, and then enters the main oil circuit 101 from the oil outlet of the electric pump 1. When the mechanical pump 2 and the electric pump 1 are started and operated at the same time, the second mechanical slide valve 303 is first controlled by the pilot valve 301 to establish an initial pressure, which is equal to the sum of the pilot pressure and the second spring preload. At this time, the oil inlet pressure of the electric pump 1 is equal to the initial pressure established by the second mechanical slide valve 303 and the pilot valve 301. After the oil enters the main oil circuit 101 through the electric pump 1, it acts on the spring opposite control port A2 of the first mechanical slide valve 302 through the damping hole. At this time, the pressure value of the spring opposite control port A2 is the main oil circuit pressure, which is balanced with the pilot pressure provided by the pilot valve 301 and the second spring preload. At the initial position, the first mechanical slide valve 302 is in the state shown in the figure, and the oil cannot flow into the third oil circuit 107. When the main oil circuit pressure reaches the system required pressure, the first mechanical slide valve 302 is opened to ensure that the pressure will not continue to rise at this time. Under the action of the second mechanical slide valve 303, the oil inlet of the electric pump 1 will produce oil with a certain pressure. When the oil enters the main oil circuit 101, further pressure regulation is achieved through the first mechanical slide valve 302. The pressure difference between the two ends of the electric pump 1 is smaller than that of directly sucking oil from the oil tank and then adjusting the main oil circuit pressure. The system reduces the power requirement of the electric pump, reduces the energy consumption of the overall hydraulic system, and improves economy.

[0038] See also Figure 2 As shown, the transmission hydraulic system pressure control device of the present application also includes a second oil circuit 105 and a second one-way valve 202; the second oil circuit 105 is arranged in parallel with the mechanical pump 2; the second one-way valve 202 is arranged in the second oil circuit 105, and the oil inlet of the second one-way valve 202 is connected to the oil inlet of the mechanical pump 2 via the second oil circuit 105, and the oil outlet of the second one-way valve 202 is respectively connected to the oil outlet of the mechanical pump 2 and the oil inlet of the electric pump 1.

[0039] The one-way valve is a valve body structure that allows oil to flow in from the oil inlet and out from the oil outlet. The first one-way valve 201 is connected to the electric pump 1 in parallel, and the second one-way valve 202 is connected to the mechanical pump 2 in parallel.

[0040] Specifically, when the oil outlet pressure of the electric pump 1 is lower than the oil inlet pressure, the first one-way valve 201 is in a cut-off state, and there is no oil in the main oil circuit 101. Therefore, the electric pump 1 will not reverse, and the oil will not flow out through the electric pump 1, but will be delivered to the clutch and shift control module 103 through the main oil circuit 101. Due to the existence of the second one-way valve 202, the oil will not flow back from the first oil circuit 104 to the second oil circuit 105. Therefore, by designing the one-way valves in parallel for the mechanical pump 2 and the electric pump 1, the working spaces of the mechanical pump 2 and the electric pump 1 are separated, and interference or idling between the mechanical pump 2 and the electric pump 1 is prevented, and the self-priming of the mechanical pump 2 or the electric pump 1 is prevented from affecting the oil supply of the hydraulic system.

[0041] See also Figure 2 As shown, the transmission hydraulic system pressure control device of the present application further includes: a damping accumulator 5, which is arranged in parallel with the pilot oil circuit 106, and the damping accumulator 5 is used to stabilize the pilot pressure output by the pilot valve 301. By arranging the damping accumulator 5 in parallel with the pilot oil circuit, the pressure fluctuation is improved and the pressure stability is improved.

[0042] Optionally, the pilot valve 301 is a normally open electromagnetic proportional valve; the pilot pressure output by the pilot valve 301 is negatively correlated with the control current of the pilot valve 301. The normally open electromagnetic valve means that when the power supply current of the electromagnetic valve is zero, the oil inlet and the oil outlet of the pilot valve 301 are connected, and the pilot pressure output by the pilot valve 301 is the maximum; as the power supply current increases, the cross-sectional area of ​​the passage between the oil inlet and the oil outlet of the pilot valve 301 becomes smaller, and the pilot pressure output by the pilot valve 301 decreases accordingly. By adopting a normally open electromagnetic valve structure, it is ensured that when the pilot valve 301 fails and cannot be controlled, the main oil circuit pressure will not be too low, and the clutch and shift control functions can still be realized to ensure driving safety.

[0043] Optionally, the rotation speed of the mechanical pump 2 is positively correlated with the engine speed. Specifically, the power source of the mechanical pump 2 is the engine, and the rotation speed of the mechanical pump 2 is positively correlated with the engine speed, that is, the higher the engine speed, the higher the rotation speed of the mechanical pump 2. By setting a mechanical oil pump to adjust the oil circuit pressure, the cost of the hydraulic system can be reduced.

[0044] Based on the inventive concept of the above-mentioned embodiment, an embodiment of the present invention provides a transmission hydraulic system pressure control method, which is implemented based on the above-mentioned transmission hydraulic system pressure control device. The transmission hydraulic system pressure control device includes an electric pump and a mechanical pump connected in series, and a first mechanical slide valve and a second mechanical slide valve controlled by the same pilot valve, and has the corresponding control logic and beneficial effects of the transmission hydraulic system pressure control device.

[0045] Figure 3A flow chart of a transmission hydraulic system pressure control method provided by an embodiment of the present invention. Figure 3 As shown, the transmission hydraulic system pressure control method of the present application includes:

[0046] S1: Control the electric pump to start or stop according to the system demand pressure.

[0047] S2: Control the first mechanical slide valve and / or the second mechanical slide valve to participate in regulating the main oil circuit pressure according to the system demand pressure.

[0048] Optionally, the first spring preload force of the first mechanical slide valve is greater than the second spring preload force of the second mechanical slide valve, and the lower limit value of the opening pressure of the first mechanical slide valve is less than the upper limit value of the regulation pressure of the second mechanical slide valve, and the upper limit value of the regulation pressure is less than the first system demand pressure when the electric pump is started.

[0049] Optionally, the first mechanical slide valve and / or the second mechanical slide valve are controlled to participate in regulating the main oil circuit pressure according to the system demand pressure, including: when the main oil circuit pressure is less than the first spring preload, the first mechanical slide valve does not participate in regulating the main oil circuit pressure; when the system demand pressure is greater than the upper limit value of the control pressure of the second mechanical slide valve and the electric pump stops running, the main oil circuit pressure is maintained at the upper limit value of the control pressure, and the first mechanical slide valve does not participate in regulating the main oil circuit pressure.

[0050] Optionally, the first mechanical slide valve and / or the second mechanical slide valve are controlled according to the system demand pressure to participate in regulating the main oil circuit pressure, including: when the system demand pressure is greater than the upper limit value of the control pressure of the second mechanical slide valve and the electric pump starts running, the first mechanical slide valve and the second mechanical slide valve simultaneously participate in regulating the main oil circuit pressure.

[0051] Based on the inventive concept of the above embodiment, an embodiment of the present invention further provides a vehicle, including: a transmission, and the above transmission hydraulic system pressure control device, which has corresponding functional modules and beneficial effects of the transmission hydraulic system pressure control device, and the same parts will not be repeated here.

[0052] In this embodiment, the vehicle is equipped with a transmission and a hydraulic system. The hydraulic system is provided with a main oil circuit connecting the clutch and the shift control module, and a cooling and lubrication control module. The vehicle includes but is not limited to: a traditional energy vehicle or a hybrid vehicle.

[0053] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0054] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A transmission hydraulic system pressure control device, characterized in that: include: Electric pump, mechanical pump, main oil circuit, cooling and lubrication control module and pressure control module; The electric pump and the mechanical pump are arranged between the hydraulic oil tank and the main oil circuit in a serially connected manner, and the electric pump is used to amplify the oil pressure at the oil outlet of the mechanical pump; The oil outlet of the mechanical pump is connected to the main oil circuit via a first oil circuit, the first oil circuit is provided with a first one-way valve, the oil inlet of the first one-way valve is connected to the oil inlet of the electric pump, and the oil outlet of the first one-way valve is connected to the oil outlet of the electric pump and the main oil circuit respectively; The pressure control module includes a pilot valve, a first mechanical slide valve, a second mechanical slide valve and a control unit; The control unit is used to control the electric pump to start or stop running according to the system demand pressure; The first mechanical slide valve is arranged between the oil outlet of the electric pump and the cooling and lubrication control module; The second mechanical slide valve is arranged between the oil outlet of the mechanical pump and the cooling and lubrication control module; The oil inlet of the pilot valve is connected to the main oil circuit, and the oil outlet of the pilot valve is respectively connected to the spring side control port of the first mechanical slide valve and the spring side control port of the second mechanical slide valve via the pilot oil circuit. The pilot valve is used to control the first mechanical slide valve and / or the second mechanical slide valve to participate in regulating the main oil circuit pressure according to the system demand pressure.

2. The transmission hydraulic system pressure control device according to claim 1, characterized in that: The first spring preload force of the first mechanical slide valve is greater than the second spring preload force of the second mechanical slide valve, and the lower limit value of the opening pressure of the first mechanical slide valve is less than the upper limit value of the regulation pressure of the second mechanical slide valve, and the upper limit value of the regulation pressure is less than the first system demand pressure when the electric pump is started.

3. The transmission hydraulic system pressure control device according to claim 2, characterized in that: The control port on the opposite side of the spring of the first mechanical slide valve is connected to the main oil circuit, and the control port on the opposite side of the spring of the second mechanical slide valve is connected to the main oil circuit; When the main oil circuit pressure is less than the first spring preload force, the first mechanical slide valve does not participate in regulating the main oil circuit pressure; When the system demand pressure is greater than the upper limit value of the regulation pressure of the second mechanical slide valve and the electric pump stops running, the main oil circuit pressure is maintained at the upper limit value of the regulation pressure, and the first mechanical slide valve does not participate in regulating the main oil circuit pressure.

4. The transmission hydraulic system pressure control device according to claim 2, characterized in that: The oil outlet of the electric pump is connected to the control port on the opposite side of the spring of the first mechanical slide valve; When the system demand pressure is greater than the control pressure upper limit value of the second mechanical slide valve and the electric pump starts to operate, the first mechanical slide valve and the second mechanical slide valve simultaneously participate in regulating the main oil circuit pressure.

5. The transmission hydraulic system pressure control device according to claim 1, characterized in that: It also includes a second oil circuit and a second one-way valve, wherein the second oil circuit is arranged in parallel with the mechanical pump; The second one-way valve is arranged in the second oil circuit, the oil inlet of the second one-way valve is connected to the oil inlet of the mechanical pump through the second oil circuit, and the oil outlet of the second one-way valve is connected to the oil outlet of the mechanical pump and the oil inlet of the electric pump respectively.

6. The transmission hydraulic system pressure control device according to claim 1, characterized in that: Also includes: A vibration damping accumulator is arranged in parallel with the pilot oil circuit, and is used to stabilize the pilot pressure output by the pilot valve.

7. The transmission hydraulic system pressure control device according to any one of claims 1 to 6, characterized in that: The pilot valve is a normally open electromagnetic proportional valve; The pilot pressure output by the pilot valve is negatively correlated with the control current of the pilot valve.

8. The transmission hydraulic system pressure control device according to any one of claims 1 to 6, characterized in that: The rotation speed of the mechanical pump is positively correlated with the engine rotation speed.

9. A transmission hydraulic system pressure control method, characterized in that: The transmission hydraulic system pressure control device according to any one of claims 1 to 8 is implemented, the transmission hydraulic system pressure control device comprises an electric pump and a mechanical pump connected in series, and a first mechanical slide valve and a second mechanical slide valve controlled by the same pilot valve, the method comprising: Control the electric pump to start or stop running according to the system demand pressure; The first mechanical slide valve and / or the second mechanical slide valve are controlled according to the system demand pressure to participate in regulating the main oil circuit pressure.

10. A vehicle, characterized in that: include: A transmission, and a transmission hydraulic system pressure control device as claimed in any one of claims 1 to 8.

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