Valve flushing method and apparatus, and electronic hydraulic braking system

Abstract

A valve flushing method and apparatus, and an electronic hydraulic braking system. When a vehicle is powered off, the electronic hydraulic braking system automatically enters a power retention state, at which point a valve flushing process is triggered. The process comprises: first controlling CSV valves to close and PSV valves to open (S101); then controlling a pressure build-up cylinder to perform pressure build-up, such that fluid in the pressure build-up cylinder flows into wheel ends via the PSV valves and IV valves (S102); when it is detected that the hydraulic pressure of the pressure build-up cylinder remains stable, controlling the PSV valves to close, so as to maintain the pressure (S103); then controlling OV valves to open to relieve the pressure, such that the fluid flows out of the wheel ends via the OV valves so as to flush valve bodies by means of fluid flow (S104); and upon expiration of a set opening duration of the OV valves, controlling the OV valves to close, and controlling the pressure build-up cylinder to perform fluid replenishment (S105).

Description

Valve washing method, device and electro-hydraulic braking system

[0001] This application claims priority to Chinese Patent Application No. 202510038773.7, filed on January 10, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of vehicle braking technology, such as a valve washing method, device, and electro-hydraulic braking system. Background Technology

[0003] Integrated Electronic Hydraulic Braking (iEHB) is an advanced automotive braking technology with particularly wide applications in the automotive field. In iEHB systems, during continuous use, debris and other foreign matter accumulate within the flow channels. This debris primarily originates from the wear generated during piston movement. When the piston is displaced within the fluid, friction between its surface and the fluid causes wear on minute amounts of material, and these wear particles are carried into the flow channels by the fluid.

[0004] Over time, during the continuous pressure build-up and depressurization process, these wear particles will gradually accumulate in the flow channel. If not cleaned in time, this may lead to valve body blockage. Valve body blockage not only affects the normal flow of fluid but may also cause a decline in the performance of the hydraulic system, such as a slower pressure build-up rate or even an inability to build pressure. This will directly affect braking performance and, consequently, vehicle safety. Summary of the Invention

[0005] In view of this, this application provides a valve washing method, apparatus and electro-hydraulic braking system to solve the above problems.

[0006] In a first aspect, this application provides a valve washing method applied to a controller of an electro-hydraulic braking system, wherein the controller is electrically connected to a pressure-building cylinder, a PSV valve, a CSV valve, an IV valve, and an OV valve of the electro-hydraulic braking system, and the method includes:

[0007] When the vehicle power is detected to be off, the CSV valve is closed and the PSV valve is opened.

[0008] The pressure-building cylinder is controlled to build up pressure so that the oil in the pressure-building cylinder flows into the wheel end through the PSV valve and the IV valve;

[0009] When the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close.

[0010] After the PSV valve is closed, the OV valve is controlled to open to release pressure, so that the oil flows out of the wheel end through the OV valve and flushes the valve body through liquid flow;

[0011] After the set opening time of the OV valve is reached, the OV valve is controlled to close, and the pressure-building cylinder is controlled to replenish the fluid.

[0012] In some embodiments, the method further includes:

[0013] After the pressure cylinder is replenished with fluid, the PSV valve is reopened.

[0014] Return to the step of controlling the pressure-building cylinder to build pressure until the valve washing count reaches the set value, then end the valve washing process.

[0015] In some embodiments, the controller is electrically connected to the motor of the pressure-building cylinder, and controls the pressure-building cylinder to replenish fluid, including:

[0016] According to the first set torque, the motor is controlled to alternately reverse and rotate forward to replenish the pressure cylinder multiple times until the replenishment is completed;

[0017] Alternatively, according to the second set torque, the motor is controlled to reverse so as to replenish the pressure cylinder once to complete the replenishment;

[0018] Wherein, the first set torque is less than the second set torque.

[0019] In some embodiments, the method further includes:

[0020] When the vehicle is detected to be powered on again or the brake pedal is displaced, it is determined whether the electro-hydraulic braking system is currently in the pressure build-up cylinder fluid replenishment stage;

[0021] If so, the motor is controlled to reverse according to the maximum set torque to replenish the pressure cylinder and then end the valve washing process;

[0022] If not, the valve washing process will end directly.

[0023] In some embodiments, before controlling the CSV valve to close and the PSV valve to open, the method further includes:

[0024] The IV valve is closed according to a set current, and after the solenoid valve of the IV valve is magnetized, the IV valve is reopened. The set current is greater than the normal operating current of the IV valve.

[0025] In some embodiments, there are four wheel ends, four IV valves and four OV valves, two PSV valves, two pressure-building cylinders connected to two PSV valves respectively, one PSV valve connected to two wheel ends through two IV valves respectively, and one wheel end connected to an oil reservoir through one OV valve;

[0026] The steps of controlling the CSV valve to close and the PSV valve to open include:

[0027] Obtain the braking response time of each wheel end when the electro-hydraulic braking system applies braking;

[0028] From all said wheel ends, identify each target wheel end whose braking response time is greater than a set threshold;

[0029] The CSV valve is closed, the PSV valve corresponding to each of the target wheel ends is opened, and the IV valve corresponding to each other wheel end except for all the target wheel ends is closed.

[0030] The step of controlling the OV valve to open for pressure relief includes:

[0031] The OV valve corresponding to each target wheel end is opened to release pressure.

[0032] In some embodiments, there are four OV valves; the step of controlling the OV valves to open for pressure relief includes:

[0033] Control all the aforementioned OV valves to open simultaneously to release pressure;

[0034] The steps for controlling the OV valve to close include:

[0035] Each of the OV valves is controlled to close sequentially according to the set order.

[0036] In some embodiments, the controller is also electrically connected to the TSV valve and SSV valve of the electro-hydraulic braking system, respectively, and the method further includes:

[0037] When the vehicle is detected to be powered off or the pressure cylinder is replenished with fluid, the CSV valve is opened, the PSV valve is opened, and the IV valve is closed.

[0038] The pressure-building cylinder is controlled to build up pressure so that the oil in the pressure-building cylinder flows into the master cylinder of the electro-hydraulic braking system through the PSV valve and the CSV valve.

[0039] When the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close, so that the oil flows out of the main cylinder through the TSV valve;

[0040] Alternatively, when the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close, the TSV valve is closed, and the SSV valve is opened, so that the oil flows out of the master cylinder through the SSV valve.

[0041] Secondly, this application also provides a valve washing device applied to the controller of an electro-hydraulic braking system. The controller is electrically connected to the pressure-building cylinder, PSV valve, CSV valve, IV valve, and OV valve of the electro-hydraulic braking system, respectively. The device includes:

[0042] The valve body control module is configured to control the CSV valve to close and the PSV valve to open when the vehicle power is detected to be off.

[0043] The pressure build-up control module is configured to control the pressure build-up of the pressure build-up cylinder so that the oil in the pressure build-up cylinder flows into the wheel end through the PSV valve and the IV valve;

[0044] The valve body control module is also configured to control the PSV valve to close when it detects that the hydraulic pressure of the pressure-building cylinder remains stable;

[0045] The pressure relief control module is configured to control the OV valve to open after the PSV valve is closed to relieve pressure, so that the oil flows out of the wheel end through the OV valve and flushes the valve body through liquid flow;

[0046] The fluid replenishment control module is configured to close the OV valve and replenish the pressure cylinder after the set opening time of the OV valve is reached.

[0047] Thirdly, this application also provides an electro-hydraulic braking system, including a controller, the controller being used in the valve washing method described in the first aspect above.

[0048] This application provides a valve washing method, device, and electro-hydraulic braking system. When the vehicle is powered off, the electro-hydraulic braking system automatically enters a power-maintaining state. At this time, the valve washing process is triggered. First, the CSV valve is controlled to close and the PSV valve is controlled to open. Then, the pressure-building cylinder is controlled to build up pressure so that the oil in the pressure-building cylinder flows into the wheel end through the PSV valve and IV valve. When the hydraulic pressure in the pressure-building cylinder is detected to be stable, the PSV valve is controlled to close. Since both the CSV valve and PSV valve are closed, the oil can be sealed between the CSV valve, PSV valve, and wheel end to maintain pressure. After that, the OV valve is controlled to open to release pressure so that the oil flows out of the wheel end through the OV valve and flushes the valve body through liquid flow. After the set opening time of the OV valve is reached, the OV valve is controlled to close and the pressure-building cylinder is controlled to replenish the oil that has been discharged to ensure sufficient oil in the circuit. Thus, by performing a valve cleaning process each time the vehicle is powered off, the valve body is flushed by the flow of liquid, and foreign objects are carried away from the valve orifice. This can significantly reduce the accumulation of foreign objects and impurities in the valve orifice, improve the performance of the electro-hydraulic braking system, and thus improve the safety of the entire vehicle. Attached Figure Description

[0049] Figure 1 shows a schematic diagram of an electro-hydraulic braking system provided in an embodiment of this application.

[0050] Figure 2 shows a block diagram of a controller provided in an embodiment of this application.

[0051] Figure 3 shows a schematic flowchart of a valve washing method provided in an embodiment of this application.

[0052] Figure 4 shows a schematic flowchart of a valve washing method provided in an embodiment of this application.

[0053] Figure 5 shows a block diagram of a valve washing device provided in an embodiment of this application.

[0054] Icons: 10-Electro-hydraulic braking system; 11-Oil reservoir module; 12-Main brake circuit; 13-Mechanical brake circuit; 14-Wheel end module; 121-Pressure-building cylinder; 1211-Piston; 1212-Pressure-building chamber; 1213-Motor; 122-Pressure sensor; 20-Controller; 21-Memory; 22-Processor; 23-Communication module; 100-Valve washing device; 101-Valve body control module; 102-Pressure-building control module; 103-Pressure relief control module; 104-Replenishment control module; 105-Valve washing control module. Detailed Implementation

[0055] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. The described embodiments are only a part of the embodiments of this application, and not all of them. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0056] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0057] Relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] To make the technical solution easier to understand, the electro-hydraulic braking system will be introduced before introducing the valve washing method provided in the embodiments of this application.

[0059] As shown in Figure 1, the electro-hydraulic braking system 10 includes a reservoir module 11, a main braking circuit 12, a mechanical braking circuit 13, a TSV valve, an SSV valve, a wheel end module 14, and a controller (not shown in the figure). The main braking circuit 12 and the mechanical braking circuit 13 are respectively connected to the reservoir module 11 and the wheel end module 14. The main braking circuit 12 and the mechanical braking circuit 13 can use the oil provided by the reservoir module 11 to generate hydraulic pressure and transmit it to the wheel end module 14 to control the vehicle braking.

[0060] The oil reservoir module 11 includes a large oil reservoir and a small oil reservoir. The large oil reservoir is configured to store oil and provide stable pressure buffering, while the small oil reservoir is configured to achieve precise hydraulic control and rapid response.

[0061] The main braking circuit 12 includes a pressure-building cylinder 121, two PSV valves (PSV1 and PSV2 in the figure), and a pressure sensor 122. The wheel end module 14 includes four IV valves (IV1F, IV1R, IV2F, and IV2R in the figure), four wheel ends (1F, 1R, 2F, and 2R in the figure), and four OV valves (OV1F, OV1R, OV2F, and OV2R in the figure). The pressure-building cylinder 121 is connected to two PSV valves respectively. One PSV valve is connected to two wheel ends through two IV valves, and one wheel end is connected to a small oil reservoir through an OV valve. That is, PSV1 is connected to 1F and 1R through IV1F and IV1R respectively, PSV2 is connected to 2F and 2R through IV2F and IV2R respectively, and 1F, 1R, 2F, and 2R are connected to the small oil reservoir through OV1F, OV1R, OV2F, and OV2R respectively.

[0062] The pressure-building cylinder 121 includes a piston 1211, a pressure-building chamber 1212, and a motor 1213. The pressure-building chamber 1212 is connected to a small oil reservoir via a one-way valve. When the motor 1213 rotates, it drives the piston 1211 to move within the pressure-building chamber 1212, thereby allowing oil to flow out of the pressure-building chamber 1212 or oil from the small oil reservoir to flow into the pressure-building chamber 1212. The pressure sensor 122 is configured to collect the hydraulic pressure of the pressure-building cylinder 121 in real time.

[0063] In wheel end module 14, two IV valves, two wheel ends, and two OV valves constitute a wheel set. Mechanical braking circuit 13 includes a brake pedal, a master cylinder, and two CSV valves (CSV1 and CSV2 in the figure). The brake pedal is connected to the master cylinder, which is connected to PSV1 and the first wheel set via CSV1, and to PSV1 and the second wheel set via CSV2. The master cylinder is also connected to a small oil reservoir via TSV valve and SSV valve, respectively.

[0064] The controller can be electrically connected via bus to the motor 1213 of the pressure cylinder 121, PSV valve, CSV valve, IV valve, OV valve, TSV valve, SSV valve and other isolation valves and devices requiring electrical control in other modules, so as to control the working status of the motor 1213 and the opening and closing of each isolation valve.

[0065] Of the isolation valves listed above, TSV, CSV, and IV valves are normally open, while SSV, PSV, and OV valves are normally closed. In the de-energized state, TSV, CSV, and IV valves are open, while SSV, PSV, and OV valves are closed. In the energized state, TSV, CSV, and IV valves are closed, while SSV, PSV, and OV valves are open.

[0066] When the vehicle requires mechanical braking, i.e. when the driver presses the brake pedal, the TSV valve, CSV valve, and IV valve open, while the PSV valve and OV valve close. The pressure build-up cylinder 121 is in a closed state with the wheel end. The oil in the small reservoir flows into the master cylinder through the TSV valve to generate hydraulic pressure. The master cylinder transmits this hydraulic pressure to the two wheel sets through the two CSV valves to achieve vehicle braking.

[0067] When the vehicle is powered off, the electro-hydraulic braking system automatically enters the power supply holding state. At this time, the valve washing process is triggered. The controller first controls the CSV valve to close and the PSV valve to open, and then controls the pressure building cylinder 121 to build up pressure so that the oil in the pressure building cylinder 121 flows into the wheel end through the PSV valve and IV valve. When the hydraulic pressure in the pressure building cylinder is detected to be stable, the PSV valve is controlled to close. At this time, since both the CSV valve and the PSV valve are closed, the oil can be sealed between the CSV valve, the PSV valve and the wheel end to maintain pressure. After that, the OV valve is controlled to open to release pressure so that the oil flows out of the wheel end through the OV valve and flushes the valve body through the liquid flow, carrying away foreign objects from the valve hole. After the set opening time of the OV valve is reached, the OV valve is controlled to close and the pressure building cylinder is controlled to replenish the oil that has been discharged to ensure sufficient oil in the circuit.

[0068] Optionally, the controller can be the vehicle's on-board computer, vehicle terminal, etc., where the electro-hydraulic braking system 10 is located, or it can be the control equipment of the electro-hydraulic braking system 10 itself.

[0069] Please refer to Figure 2, which is a block diagram of the controller 20 in the electro-hydraulic braking system 10 shown in Figure 1. The controller 20 includes a memory 21, a processor 22, and a communication module 23. The memory 21, processor 22, and communication module 23 are electrically connected to each other directly or indirectly to realize data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines.

[0070] The memory 21 is used to store programs or data. For example, the valve washing device shown in Figure 5 below includes at least one software function module that can be stored in the memory 21 in the form of software or firmware. After receiving the execution instruction, the processor 22 executes the program to implement the valve washing method disclosed in this embodiment.

[0071] The memory 21 can be a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc.

[0072] The processor 22 is used to read / write data or programs stored in the memory 21 and to perform corresponding functions. For example, in the electro-hydraulic braking system 10 shown in FIG1, the processor 22 in the controller 20 executes the computer program stored in the memory 21 to implement the valve washing method provided in the embodiments of this application.

[0073] The processor 22 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the valve washing method provided in this embodiment can be completed by the integrated logic circuitry in the processor 22 or by software instructions. The processor 22 described above can be a general-purpose processor, including a central processing unit (CPU), a microcontroller unit (MCU), a complex programmable logic device (CPLD), a field programmable gate array (FPGA), an embedded ARM chip, etc.

[0074] The communication module 23 is used to establish communication connections between the controller 20 and other communication terminals, sensors, and solenoid valves via wireless communication such as networks, WiFi, and Bluetooth, or via communication data lines such as buses, and is used to send and receive data. For example, in the electro-hydraulic braking system 10 shown in Figure 1, the controller 20 can receive detection data from various sensors through the communication module 23, and send control signals to TSV valves, CSV valves, PSV valves, SSV valves, IV valves, OV valves, etc.

[0075] The structure shown in Figure 2 is only a schematic diagram of the controller 20. The controller 20 may also include more or fewer components than shown in Figure 2, or have a different configuration than shown in Figure 2. The components shown in Figure 2 can be implemented using hardware, software, or a combination thereof.

[0076] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by processor 22, implements the valve washing method disclosed in this embodiment.

[0077] Based on the electro-hydraulic braking system 10 and controller 20 described above, the valve washing method provided in the embodiments of this application will be described in detail.

[0078] Please refer to Figure 3, which shows a schematic flowchart of the valve washing method provided in this application. This valve washing method is applied to the controller in the electro-hydraulic braking system 10 and may include the following steps:

[0079] S101, when the vehicle power is detected to be off, controls the CSV valve to close and the PSV valve to open.

[0080] S102 controls the pressure build-up of the pressure build-up cylinder so that the oil in the pressure build-up cylinder flows into the wheel end through the PSV valve and IV valve.

[0081] S103, when the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close.

[0082] S104 After the PSV valve is closed, the OV valve is controlled to open to release pressure, so that the oil flows out of the wheel end through the OV valve and flushes the valve body through the liquid flow.

[0083] S105: After the set opening time of the OV valve is reached, control the OV valve to close and control the pressure-building cylinder to replenish the liquid.

[0084] In this embodiment, when the driver stops the vehicle and turns off the engine, the entire vehicle is powered off. At this time, the electro-hydraulic braking system 10 automatically enters the power supply holding state, and the valve washing process is triggered.

[0085] Referring to Figure 1, after the valve washing process begins, the CSV valve is first controlled to close and the PSV valve to open. Then, the pressure-building cylinder 121 is controlled to build up pressure. That is, the motor 1213 rotates forward, driving the piston 1211 to move towards the bottom of the pressure-building chamber 1212 to generate hydraulic pressure. Since the CSV valve has been controlled to close and the PSV valve to open, and the IV valve is a normally open valve, the pressure-building chamber 1212 can transmit the generated hydraulic pressure to the wheel end through the two PSV valves respectively. In other words, the oil in the pressure-building cylinder 121 flows into the wheel end through the PSV valve and the IV valve.

[0086] In step S102, the method of controlling the pressure-building cylinder to build pressure can be flexibly selected. For example, the pressure-building cylinder can build the same hydraulic pressure in multiple valve washes, or the pressure-building cylinder can build different hydraulic pressures in multiple valve washes. The implementation method can be flexibly set.

[0087] Optionally, in step S102, when controlling the pressure-building cylinder to build up pressure, the pressure can be controlled according to the target pressure. The target pressure can be a value obtained by fitting a large amount of historical data or calibration test data, or it can be a value set by technicians based on experience, for example, 50 bar. The target pressure setting only needs to ensure that the liquid flow can flush the valve body and carry foreign objects away from the valve orifice.

[0088] Simultaneously, during the pressure-building process of the pressure-building cylinder 121, the hydraulic pressure of the pressure-building cylinder 121 can be collected in real time by the pressure sensor 122. When the hydraulic pressure of the pressure-building cylinder 121 remains stable (i.e., the reading of the pressure sensor 122 remains unchanged), it indicates that the pressure-building cylinder 121 has completed pressure building. At this time, the PSV valve is closed. Since both the CSV valve and the PSV valve are closed, the oil can be sealed between the CSV valve, the PSV valve, and the wheel end to maintain pressure and improve the subsequent valve cleaning effect. Afterward, the OV valve is opened to release pressure, so that the oil flows out of the wheel end through the OV valve and returns to the small oil reservoir. During this process, the valve body can be flushed by the liquid flow, carrying foreign objects away from the valve orifice, thereby ensuring the valve flow rate. After the set opening time of the OV valve is reached, the OV valve is closed, and the replenishment mode is entered to replenish the lost oil of the pressure-building cylinder 121 and ensure sufficient oil in the circuit.

[0089] In step S105, the set opening time of the OV valve can be obtained by fitting a large amount of historical data or calibration test data, or it can be set by technicians based on experience, for example, 1 second. The following two principles can be referenced when setting the opening time: 1. Since the OV valve is noisy when it opens, its opening time should theoretically be as short as possible; 2. Based on point 1, although theoretically the shorter the opening time of the OV valve, the better, it should not be shorter than the time it takes for the liquid flow to flush the valve body and carry foreign objects away from the valve orifice.

[0090] After entering the replenishment mode, the control motor reverses, driving piston 1211 to move towards the top of pressure chamber 1212, creating a pressure difference between pressure chamber 1212 and the small oil reservoir. At this time, the one-way valve opens, and the oil in the small oil reservoir flows into pressure chamber 1212, thus achieving replenishment. If the motor reverses with high torque, the pressure difference generated is large enough to fill pressure chamber 1212 with oil in one go. However, if the motor reverses with low torque, the pressure difference generated is small enough not to fill pressure chamber 1212 with oil in one go. In this case, motor 1213 needs to be controlled to rotate forward, driving piston 1211 towards the bottom of pressure chamber 1212. Then, motor 1213 is controlled to reverse again to continue replenishing pressure chamber 1212 with oil. This process is repeated 2-3 times until pressure chamber 1212 is filled with oil. Since the PSV valve has been closed in step S103, when the control motor 1213 rotates forward and drives the piston 1211 to move towards the bottom of the pressure chamber 1212, the oil will not flow out of the pressure chamber 1212, so the oil can be replenished in multiple times.

[0091] Optionally, the process of controlling the pressure-building cylinder to replenish fluid in step S105 may include:

[0092] According to the first set torque, the motor is controlled to alternately reverse and rotate forward to replenish the pressure cylinder multiple times until the replenishment is completed; or, according to the second set torque, the motor is controlled to reverse to replenish the pressure cylinder once to complete the replenishment; wherein, the first set torque is less than the second set torque.

[0093] The first set torque and the second set torque can be flexibly set according to the actual situation. As long as the noise is low when the motor is reversed by the first set torque and the liquid replenishment can be completed in one go when the motor is reversed by the second set torque, the second set torque can be the maximum torque, which can complete the liquid replenishment in the millisecond time.

[0094] In other words, in step S105, controlling the pressure-building cylinder to replenish fluid can be done by either controlling the motor to rotate at high speed to replenish the lost fluid in one go, or by controlling the motor to rotate at low speed to replenish in multiple stages. High-speed motor rotation is noisier but can complete the replenishment in one go, while low-speed motor rotation is quieter but requires multiple stages to complete the replenishment. The two replenishment methods can be flexibly selected in practice. For example, in a normal valve washing process, the motor can be controlled to rotate at low speed to replenish in multiple stages to reduce noise. However, if the vehicle is detected to be powered back on or the driver has pressed the brake pedal, and the valve washing process needs to be quickly ended, then the motor can be controlled to rotate at high speed to complete the replenishment in one go.

[0095] The above describes a single valve washing process. In practice, to achieve a better valve washing effect, multiple valve washings may be required. Therefore, based on Figure 3 and referring to Figure 4, the valve washing method provided in this application embodiment also includes steps S106 to S107.

[0096] S106, after the hydraulic cylinder is replenished, control the PSV valve to reopen.

[0097] S107, return to steps S102 to S105 until the valve washing count reaches the set value, then end the valve washing process.

[0098] The set value for the number of valve washes can be flexibly set according to the actual situation, such as based on a large amount of historical data or calibration test data, or set by technicians based on experience, for example, 5 times.

[0099] The above valve washing process is triggered and executed when the driver stops the vehicle and turns off the engine, and the vehicle is powered off. If the vehicle is powered back on or the driver presses the brake pedal during the valve washing process, the valve washing process needs to be ended. At this time, if the valve washing process is in the fluid replenishment stage, that is, the pressure cylinder is being controlled to replenish fluid, the fluid replenishment must be completed quickly. For example, the motor is controlled to reverse at maximum torque to complete the fluid replenishment within milliseconds, and then the valve washing process ends. If the valve washing process is not in the fluid replenishment stage, the valve washing process should be ended immediately to ensure braking safety.

[0100] Therefore, in one possible implementation, the valve washing method provided in this application embodiment further includes steps S10a to S10c.

[0101] S10a: When the vehicle is detected to be powered on again or the brake pedal is displaced, determine whether the electronic hydraulic braking system is currently in the pressure build-up cylinder fluid replenishment stage.

[0102] S10b, if the electro-hydraulic braking system is currently in the pressure-building cylinder replenishment stage, the motor is controlled to reverse according to the maximum set torque to replenish the pressure-building cylinder and then end the valve washing process.

[0103] S10c, if the electro-hydraulic braking system is not currently in the pressure cylinder replenishment stage, the valve washing process will end directly.

[0104] In some possible implementations, after the valve washing process is triggered but before it begins execution, a large current greater than the normal operating current can be used to energize the IV valve. That is, the IV valve is closed to magnetize the solenoid valve of the IV valve, and then the power is cut off to open the IV valve. After that, the valve washing process is executed. Since the solenoid valve of the IV valve is magnetized, the flow rate of the IV valve orifice can be increased during the valve washing process, thereby improving the valve washing effect.

[0105] That is, before controlling the CSV valve to close and the PSV valve to open in step S101, the valve washing method provided in this application embodiment further includes step S10A.

[0106] S10A controls the IV valve to close according to the set current, so as to re-open the IV valve after the solenoid valve of the IV valve is magnetized. The set current is greater than the normal operating current of the IV valve.

[0107] As can be seen from Figure 1, there are four IV valves and four OV valves in the electro-hydraulic braking system 10. In practice, only some valve holes may be blocked. Therefore, in order to further improve the valve cleaning effect, the valves with blocked valve holes can be identified first, and then the valves with blocked valve holes can be cleaned.

[0108] Therefore, the process of controlling the CSV valve to close and the PSV valve to open in step S101 may include: acquiring the braking response time of each wheel end when braking occurs in the electro-hydraulic braking system; determining each target wheel end whose braking response time is greater than a set threshold from all the wheel ends; controlling the CSV valve to close, the PSV valve corresponding to each target wheel end to open, and the IV valve corresponding to each other wheel end except for all target wheel ends to close. The process of controlling the OV valve to open for pressure relief in step S104 may include: controlling the OV valve corresponding to each target wheel end to open for pressure relief.

[0109] That is, when the electro-hydraulic braking system 10 brakes, the braking response time of the four wheel ends is acquired. If the braking response time of a certain wheel end is greater than the set threshold, it is considered that the valve orifice of the IV valve and OV valve corresponding to that wheel end is blocked. For example, the valve orifice corresponding to 1F in Figure 1 is blocked. At this time, the CSV is controlled to close, PSV1 is controlled to open, and IV1R is controlled to close. Then, the subsequent valve washing strategy is carried out. That is, the pressure building cylinder 121 is controlled to build up pressure so that the oil in the pressure building cylinder 121 flows into the wheel end through the PSV1 and IV1F valves. When it is detected that the hydraulic pressure of the pressure building cylinder 121 is stable, the PSV1 is controlled to close to maintain pressure, and then the OV1F is controlled to open to release pressure so that the oil flows out of the wheel end through the OV1F and flushes the valve body through the liquid flow, carrying away foreign objects from the valve orifice. Thus, only IV1F and OV1F can be flushed, which improves the valve washing effect.

[0110] In some possible implementations, when the OV valve is open, it can open all valves that need to be cleaned to relieve pressure. Here, all valves that need to be cleaned can be all OV valves, or the OV valves corresponding to each target wheel end as determined above. When closed, they are closed in a set order. For example, the four OA valves in Figure 1 are closed sequentially from left to right. In this way, the hydraulic pressure will be continuously transmitted to the rear, improving the valve cleaning effect.

[0111] Therefore, the process of controlling the OV valves to open for pressure relief in step S104 can include: controlling all OV valves to open simultaneously for pressure relief. The process of controlling the OV valves to close in step S105 can include: controlling each OV valve to close sequentially according to a set order.

[0112] The order can be flexibly set according to the actual situation. For example, when the electro-hydraulic braking system 10 brakes, the braking response time of the four wheel ends is obtained to determine the blockage of the valve holes corresponding to each wheel end, and they are sorted in order from low to high. When the OA valve is closed, it is closed in this order, that is, closed in order from low blockage to high blockage.

[0113] The valve washing process described above uses liquid flow to flush the PSV, IV, and OV valves, removing foreign matter from their orifices. This significantly reduces the accumulation of impurities in the valve orifices, improving the performance of the electro-hydraulic braking system and ultimately enhancing vehicle safety. In practice, because the PSV and IV valves are normally open, while the OV valve is normally closed, foreign matter primarily accumulates in the OV valve orifice. The pressure build-up and release process described above effectively removes foreign matter from the OV valve orifice.

[0114] In addition to flushing the PSV, IV, and OV valves in the electro-hydraulic braking system, the valve flushing method provided in this application embodiment can also flush the TSV, SSV, and CSV valves, which will be described below.

[0115] In one optional implementation, the valve washing method provided in this application embodiment further includes steps S201 to S203.

[0116] S201: When the vehicle is detected to be powered off or the pressure cylinder is replenished, the CSV valve is opened, the PSV valve is opened, and the IV valve is closed.

[0117] S202 controls the pressure build-up of the pressure build-up cylinder so that the oil in the pressure build-up cylinder flows into the master cylinder of the electro-hydraulic braking system through the PSV valve and CSV valve.

[0118] S203, when the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close so that the oil flows out of the main cylinder through the TSV valve; or, when the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close, the TSV valve is controlled to close, and the SSV valve is controlled to open so that the oil flows out of the main cylinder through the SSV valve.

[0119] In other words, since the inlet and outlet of the master cylinder are open after the vehicle is powered off, this characteristic can be used to flush the TSV, SSV, and CSV valves. Referring to Figure 1, the TSV, SSV, and CSV valves can be flushed when the vehicle is detected to be powered off, or they can be flushed after the IV and OV valves have been flushed.

[0120] When flushing the TSV, SSV, and CSV valves is required, the controller first opens the CSV valve and the PSV valve, and closes the IV valve. Then, it controls the pressure-building cylinder 121 to build pressure, allowing the oil in cylinder 121 to flow into the main cylinder via the PSV and CSV valves, thus completing the flushing of the CSV valve. When the hydraulic pressure in the pressure-building cylinder is detected to be stable, the PSV valve is closed. Since the TSV valve is normally open, the oil can flow back from the main cylinder to the small oil reservoir through the TSV valve, thus completing the flushing of the TSV valve. Alternatively, when the hydraulic pressure in the pressure-building cylinder is detected to be stable, the PSV valve is closed, the TSV valve is closed, and the SSV valve is opened. This allows the oil to flow back from the main cylinder to the small oil reservoir through the SSV valve, thus completing the flushing of the SSV valve.

[0121] Meanwhile, since there are two CSV valves, in order to improve the flushing effect and avoid the piston of the master cylinder moving due to excessive pressure when the oil flows into the master cylinder, the two CSV valves can be flushed separately.

[0122] When CSV1 needs to be flushed, the controller first opens the PSV valve, closes the IV valve, and closes CSV2. Then, it controls the pressure-building cylinder 121 to build up pressure, allowing the oil in the pressure-building cylinder 121 to flow into the main cylinder through the PSV valve and CSV1, thus completing the flushing of CSV1. When the hydraulic pressure in the pressure-building cylinder is detected to be stable, the PSV valve is closed. Since the TSV valve is a normally open valve, the oil can flow back from the main cylinder to the small oil reservoir through the TSV valve, thus completing the flushing of the TSV valve. Alternatively, when the hydraulic pressure in the pressure-building cylinder is detected to be stable, the PSV valve is closed, the TSV valve is closed, and the SSV valve is opened. This allows the oil to flow back from the main cylinder to the small oil reservoir through the SSV valve, thus completing the flushing of the SSV valve.

[0123] When CSV2 needs to be flushed, the controller first controls the PSV valve to open, the IV valve to close, and the CSV1 to close. Then, it controls the pressure-building cylinder 121 to build up pressure so that the oil in the pressure-building cylinder 121 flows into the main cylinder through the PSV valve and CSV2. At this time, the flushing of CSV2 can be completed. When the hydraulic pressure of the pressure-building cylinder is detected to be stable, the PSV valve is controlled to close, and the oil flows back to the small oil reservoir through the outlet of the main cylinder.

[0124] In order to perform the corresponding steps in the above embodiments and various possible implementations, an implementation of a valve washing device is given below.

[0125] Please refer to Figure 5, which is a functional module diagram of the valve washing device 100 provided in this application. It should be noted that the basic principle and technical effects of the valve washing device 100 described in this embodiment are the same as those in the aforementioned method embodiments. For the sake of brevity, parts not mentioned in this embodiment can be referred to the corresponding content in the aforementioned method embodiments. This valve washing device 100 is applied to the controller of the electro-hydraulic braking system 10. The valve washing device 100 will be described below with reference to Figure 5. The valve washing device 100 includes: a valve body control module 101, a pressure build-up control module 102, a pressure relief control module 103, and a fluid replenishment control module 104.

[0126] The valve body control module 101 is configured to control the CSV valve to close and the PSV valve to open when the vehicle is detected to be powered down.

[0127] The pressure build-up control module 102 is configured to control the pressure build-up of the pressure build-up cylinder so that the oil in the pressure build-up cylinder flows into the wheel end through the PSV valve and IV valve.

[0128] The valve body control module 101 is also configured to control the PSV valve to close when it is detected that the hydraulic pressure of the pressure build-up cylinder remains stable.

[0129] The pressure relief control module 103 is configured to control the OV valve to open after the PSV valve is closed to relieve pressure, so that the oil flows out of the wheel end through the OV valve and flushes the valve body through the liquid flow.

[0130] The fluid replenishment control module 104 is configured to control the OV valve to close and control the pressure-building cylinder to replenish fluid after the set opening time of the OV valve is reached.

[0131] Optionally, the valve washing device 100 provided in this application embodiment further includes a valve washing control module 105. The valve washing control module 105 is configured to control the PSV valve to reopen after the liquid replenishment of the pressure cylinder is completed; return to the execution steps S102 to S105 until the number of valve washings reaches the set value, and end the valve washing process.

[0132] Optionally, the pressure building control module 102 executes the pressure building method of the pressure building cylinder, including: according to a first set torque, controlling the motor to alternately reverse and forward rotation to replenish the pressure building cylinder multiple times until the replenishment is completed; or, according to a second set torque, controlling the motor to reverse rotation to replenish the pressure building cylinder once to complete the replenishment; wherein, the first set torque is less than the second set torque.

[0133] Optionally, the valve washing control module 105 is also configured to determine whether the electro-hydraulic braking system is currently in the pressure cylinder replenishment stage when the vehicle is detected to be powered on again or the brake pedal is displaced; if so, the motor is controlled to reverse according to the maximum set torque to replenish the pressure cylinder and then the valve washing process is ended; if not, the valve washing process is ended directly.

[0134] Optionally, the valve washing control module 105 is further configured to control the IV valve to close according to a set current, so as to control the IV valve to reopen after the solenoid valve of the IV valve is magnetized, wherein the set current is greater than the normal operating current of the IV valve.

[0135] Optionally, the valve body control module 101 executes a method of controlling the CSV valve to close and the PSV valve to open when the vehicle power is detected to be off, including: acquiring the braking response time of each wheel end when braking occurs in the electro-hydraulic braking system; determining each target wheel end whose braking response time is greater than a set threshold from all the wheel ends; controlling the CSV valve to close, the PSV valve corresponding to each target wheel end to open, and the IV valve corresponding to each other wheel end except for all target wheel ends to close.

[0136] The pressure relief control module 103 executes the method of controlling the OV valve to open for pressure relief, including: controlling the OV valve corresponding to each target wheel end to open for pressure relief.

[0137] Optionally, the pressure relief control module 103 may control the OV valves to open for pressure relief, including controlling all OV valves to open simultaneously for pressure relief.

[0138] The fluid replenishment control module 104 executes the control of the OV valve closing method, including: controlling each OV valve to close sequentially according to a set order.

[0139] Optionally, the valve washing control module 105 is further configured to, when detecting that the vehicle is powered off or that the pressure-building cylinder has been replenished, control the CSV valve to open, the PSV valve to open, and the IV valve to close; control the pressure-building cylinder to build up pressure so that the oil in the pressure-building cylinder flows into the master cylinder of the electro-hydraulic braking system through the PSV valve and the CSV valve; when detecting that the hydraulic pressure of the pressure-building cylinder remains stable, control the PSV valve to close so that the oil flows out of the master cylinder through the TSV valve; or, when detecting that the hydraulic pressure of the pressure-building cylinder remains stable, control the PSV valve to close, the TSV valve to close, and the SSV valve to open so that the oil flows out of the master cylinder through the SSV valve.

[0140] In summary, the valve washing method and apparatus, controller, and electro-hydraulic braking system provided in this application have at least the following beneficial effects:

[0141] First, a valve cleaning process is performed each time the vehicle is powered off. The flow of liquid flushes the valve body, carrying away foreign objects from the valve orifice. This significantly reduces the accumulation of foreign objects and impurities in the valve orifice, improves the performance of the electro-hydraulic braking system, and thus enhances the safety of the entire vehicle.

[0142] Secondly, during the valve washing process, if the vehicle is powered back on or the driver presses the brake pedal, if the valve washing process is in the fluid replenishment stage, the fluid replenishment should be completed quickly, and then the valve washing process should be ended. If the valve washing process is not in the fluid replenishment stage, the valve washing process should be ended immediately to ensure braking safety.

[0143] Third, after the valve washing process is triggered but before it begins to be executed, a large current greater than the normal operating current can be used to energize the IV valve to magnetize the IV valve's solenoid valve. This can increase the flow rate of the IV valve's orifice during the subsequent valve washing process and improve the valve washing effect.

[0144] Fourth, during the valve cleaning process, the IV and OV valves with blocked valve holes can be identified by measuring the braking response time at each wheel end. Only the valves with blocked valve holes are cleaned, which improves the valve cleaning effect.

[0145] Fifth, when the OV valve is open, it can open all valves that need valve cleaning to relieve pressure, and when it is closed, it closes them one by one in a set order. In this way, the hydraulic pressure will be continuously transmitted to the next valve, which improves the valve cleaning effect.

[0146] Sixth, when replenishing the pressure cylinder, the motor can be controlled to rotate at high speed to replenish the lost oil in one go, or the motor can be controlled to rotate at low speed to replenish the oil that has been discharged, so as to ensure that the oil in the circuit is sufficient.

[0147] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0148] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0149] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to related technologies, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A valve washing method applied to a controller of an electro-hydraulic braking system, wherein the controller is electrically connected to a pressure-building cylinder, a PSV valve, a CSV valve, an IV valve, and an OV valve of the electro-hydraulic braking system, the method comprising: When the vehicle power is detected to be off, the CSV valve is closed and the PSV valve is opened. The pressure-building cylinder is controlled to build up pressure so that the oil in the pressure-building cylinder flows into the wheel end through the PSV valve and the IV valve; When the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close. After the PSV valve is closed, the OV valve is controlled to open to release pressure, so that the oil flows out of the wheel end through the OV valve and flushes the valve body through liquid flow; After the set opening time of the OV valve is reached, the OV valve is controlled to close, and the pressure-building cylinder is controlled to replenish the fluid.

2. The valve washing method according to claim 1 further includes: After the pressure cylinder is replenished with fluid, the PSV valve is reopened. Return to the step of controlling the pressure-building cylinder to build pressure until the valve washing count reaches the set value, then end the valve washing process.

3. The valve washing method according to claim 1, wherein, The controller is electrically connected to the motor of the pressure-building cylinder. The control of the pressure-building cylinder to replenish fluid includes: According to the first set torque, the motor is controlled to alternately reverse and rotate forward to replenish the pressure cylinder multiple times until the replenishment is completed; Alternatively, according to the second set torque, the motor is controlled to reverse so as to replenish the pressure cylinder once to complete the replenishment; Wherein, the first set torque is less than the second set torque.

4. The valve washing method according to claim 1 further includes: When the vehicle is detected to be powered on again or the brake pedal is displaced, it is determined whether the electro-hydraulic braking system is currently in the pressure build-up cylinder fluid replenishment stage; If so, the motor is controlled to reverse according to the maximum set torque to replenish the pressure cylinder and then end the valve washing process; If not, the valve washing process will end directly.

5. The valve washing method according to claim 1, further comprising, before controlling the CSV valve to close and the PSV valve to open: The IV valve is closed according to a set current, and after the solenoid valve of the IV valve is magnetized, the IV valve is reopened. The set current is greater than the normal operating current of the IV valve.

6. The valve washing method according to claim 1, wherein, There are four wheel ends, four IV valves and four OV valves, two PSV valves, and the pressure build-up cylinders are connected to two PSV valves respectively. One PSV valve is connected to two wheel ends through two IV valves, and one wheel end is connected to an oil reservoir through one OV valve. The steps of controlling the CSV valve to close and the PSV valve to open include: Obtain the braking response time of each wheel end when the electro-hydraulic braking system applies braking; From all said wheel ends, identify each target wheel end whose braking response time is greater than a set threshold; The CSV valve is closed, the PSV valve corresponding to each of the target wheel ends is opened, and the IV valve corresponding to each other wheel end except for all the target wheel ends is closed. The step of controlling the OV valve to open for pressure relief includes: The OV valve corresponding to each target wheel end is opened to release pressure.

7. The valve washing method according to claim 1, wherein, There are four OV valves; The step of controlling the OV valve to open for pressure relief includes: Control all the aforementioned OV valves to open simultaneously to release pressure; The steps of controlling the OV valve to close include: Each of the OV valves is controlled to close sequentially according to the set order.

8. The valve washing method according to claim 1, wherein, The controller is also electrically connected to the TSV valve and SSV valve of the electro-hydraulic braking system, respectively, and the method further includes: When the vehicle is detected to be powered off or the pressure cylinder is replenished with fluid, the CSV valve is opened, the PSV valve is opened, and the IV valve is closed. The pressure-building cylinder is controlled to build up pressure so that the oil in the pressure-building cylinder flows into the master cylinder of the electro-hydraulic braking system through the PSV valve and the CSV valve. When the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close, so that the oil flows out of the main cylinder through the TSV valve; Alternatively, when the hydraulic pressure of the pressure-building cylinder is detected to remain stable, the PSV valve is controlled to close, the TSV valve is closed, and the SSV valve is opened, so that the oil flows out of the master cylinder through the SSV valve.

9. A valve washing device, applied to a controller of an electro-hydraulic braking system, the controller being electrically connected to a pressure-building cylinder, a PSV valve, a CSV valve, an IV valve, and an OV valve of the electro-hydraulic braking system, the device comprising: The valve body control module is configured to control the CSV valve to close and the PSV valve to open when the vehicle power is detected to be off. The pressure build-up control module is configured to control the pressure build-up of the pressure build-up cylinder so that the oil in the pressure build-up cylinder flows into the wheel end through the PSV valve and the IV valve; The valve body control module is also configured to control the PSV valve to close when it detects that the hydraulic pressure of the pressure-building cylinder remains stable; The pressure relief control module is configured to control the OV valve to open after the PSV valve is closed to relieve pressure, so that the oil flows out of the wheel end through the OV valve and flushes the valve body through liquid flow; The fluid replenishment control module is configured to close the OV valve and replenish the pressure cylinder after the set opening time of the OV valve is reached.

10. An electro-hydraulic braking system, comprising a controller for performing the valve washing method according to any one of claims 1-8.

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