A dual-mode hydraulic brake system and control method

Abstract

The present invention provides a dual-mode hydraulic brake system and a control method, which relate to the technical field of vehicle braking. The brake control component includes a manned mode brake control oil circuit and an unmanned mode brake control oil circuit, which can realize the switching between manned control braking and unmanned remote control braking. The dual-mode hydraulic brake system can meet the two working conditions of manned driving and unmanned remote control driving, and solves the technical problem of the working condition of only manned driving mode but not unmanned remote control driving mode. The setting of the brake execution component can improve the braking force, so that the vehicle can perform slow and smooth deceleration braking, steep slope parking braking and long-term parking braking, and solves the technical problem of long braking distance due to small braking force. The setting of the non-leakage pressure-maintaining control oil circuit during driving can solve the technical problem that the vehicle cannot be parked for a long time due to hydraulic leakage.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle braking, and in particular to a dual-mode hydraulic braking system and a control method. Background Art

[0002] Medium-sized special vehicles are special vehicles that weigh about 23 tons, have a maximum speed of 80 kilometers per hour, and adopt two driving modes: manned driving and unmanned remote control driving. Due to their heavy weight and high speed, they need to adapt to various road conditions and scenarios, and have high requirements for the braking system. Ordinary hydraulic braking systems are difficult to meet their requirements, such as: the braking distance is long due to small braking force, and the vehicle cannot be parked for a long time due to hydraulic leakage. There is only a manned driving mode but no unmanned remote control driving mode. Summary of the invention

[0003] The present invention provides a dual-mode hydraulic brake system and a control method to solve at least one of the technical problems that the above-mentioned ordinary hydraulic brake system is difficult to meet the requirements, such as: a long braking distance due to small braking force, an inability to park for a long time due to hydraulic leakage, and only a manned driving mode but no unmanned remote control driving mode.

[0004] In order to solve the above technical problems, the present invention discloses a dual-mode hydraulic braking system, including a brake actuator component, a hydraulic power component and a brake control component. The hydraulic power component is connected to the brake actuator component through the brake control component. The brake control component includes a leakage-free pressure-maintaining control oil circuit for driving, a manned mode brake control oil circuit and an unmanned mode brake control oil circuit.

[0005] Preferably, the brake actuator assembly includes a mounting support, a floating support is fixedly mounted on the mounting support, an annular hydraulic cylinder is slidably mounted on the floating support, the annular hydraulic cylinder is fixedly connected to a friction pair, and the friction pair includes a brake pad and a brake disc.

[0006] Preferably, the hydraulic power assembly includes an oil tank, in which a liquid level thermometer is installed, the liquid level thermometer is electrically connected to the liquid temperature alarm through a temperature switch, an air filter is installed on the oil tank, the oil tank is connected to the hydraulic pump, the hydraulic pump is connected to the DC motor, the hydraulic pump is connected to the one-way valve through the main oil circuit, and a plug-in filter is installed on the main oil circuit between the hydraulic pump and the one-way valve, the main oil circuit is connected to a pressure regulating oil circuit, and the pressure regulating oil circuit is connected to the overflow valve.

[0007] Preferably, the brake control component also includes an accumulator energy storage control oil circuit, a mode switching control valve and a safety valve. The accumulator energy storage control oil circuit includes an accumulator. The accumulator is connected to the accumulator pressure sensor and the pressure measuring joint through the energy storage oil circuit. The energy storage oil circuit is connected to the main oil circuit.

[0008] Preferably, the leakage-free driving pressure-maintaining control oil circuit includes solenoid valve 1, port 1 of solenoid valve 1 is connected to the main oil circuit, port 2 of solenoid valve 1 is connected to branch oil circuit 1, a leakage-free direct-acting pressure reducing valve is installed on branch oil circuit 1, branch oil circuit 1 is connected to port 1 of solenoid valve 2, port 2 of solenoid valve 2 is connected to brake cylinder 1 and brake cylinder 2 respectively through branch oil circuit 2, and a brake pressure sensor is installed on branch oil circuit 2.

[0009] Preferably, the manned mode brake control oil circuit includes a pedal brake valve, port 1 of the pedal brake valve is connected to port 1 of the mode switching control valve through branch oil circuit 3, port 2 of the mode switching control valve is connected to port 3 of solenoid valve 1 through branch oil circuit 4, port 2 of the pedal brake valve is connected to port 1 of the manual parking valve through branch oil circuit 5, and port 2 of the manual parking valve is connected to branch oil circuit 8.

[0010] Preferably, the unmanned mode brake control oil circuit includes solenoid valve three, port one of solenoid valve three is connected with port three of the mode switching control valve through branch oil circuit ten, port two of solenoid valve three is connected with port one of the electric proportional pressure reducing valve through branch oil circuit six, branch oil circuit six is ​​connected with the side branch oil circuit, the side branch oil circuit is connected with branch oil circuit seven, a one-way valve is installed on the side branch oil circuit, port two of the shuttle valve is connected with branch oil circuit eight, and port three of the shuttle valve is connected with port three of solenoid valve two through branch oil circuit eleven.

[0011] Preferably, the port three of the solenoid valve three, the pedal brake valve and the manual parking valve are all connected to the pressure relief oil circuit one through the pressure relief oil circuit two, the pressure relief oil circuit one is connected to the outlet of the safety valve, the inlet of the safety valve is connected to the branch oil circuit nine, and the branch oil circuit nine is connected to the branch oil circuit two.

[0012] Preferably, the method further includes an automatic pressure replenishment method for an accumulator, comprising the following steps:

[0013] Step 1: Install the flow rate sensor at the connection point between the accumulator and the energy storage oil circuit to detect the oil outlet flow rate of the accumulator;

[0014] Step 2: The controller is electrically connected to the flow rate sensor and the timer, and the timer is used to detect the working time when the detection value of the flow rate sensor is not 0;

[0015] Step 3: The controller calculates the theoretical time required for the accumulator to replenish pressure based on the detection value of the flow rate sensor and formula (1);

[0016] ; (1)

[0017] in, is the theoretical time required for the accumulator to replenish pressure, is the oil storage capacity of the accumulator, is the working volume of the annular hydraulic cylinder, is the pre-charge pressure of the accumulator, is the effective diameter of the safety valve; is the maximum detection value of the accumulator pressure sensor, is the stiffness coefficient of the brake spring, is the extension and contraction distance of the brake spring, is the flow area of ​​the energy storage oil circuit, is the flow velocity of the energy storage oil circuit, is the value of pi, which is 3.14;

[0018] Step 4: When the timer detects that the working time of the accumulator is the same as the theoretical time required for the accumulator to replenish pressure calculated in step 3, the timer controls the accumulator to automatically replenish pressure through the controller.

[0019] A control method for a dual-mode hydraulic brake system comprises the following steps:

[0020] Step 5: During normal driving, the hydraulic power assembly and the brake control assembly increase a certain pressure in the annular hydraulic cylinder to compress the disc spring inside the annular hydraulic cylinder. At this time, a gap is generated between the brake pad and the brake disc, and no braking torque is generated, so the vehicle can drive normally.

[0021] Step 6: When the vehicle needs to brake, the brake control component is controlled to release the pressure on the annular hydraulic cylinder. Under the action of the internal disc spring, the annular hydraulic cylinder extends, pushing the brake pad to move axially until it contacts the brake disc. Under the reaction force of the brake disc, the brake pad drives the annular hydraulic cylinder to slide in the direction of the reaction force as a whole, and at the same time pulls the brake pad on the other side close to the brake disc. When the brake pads on both sides are attached to the brake disc at the same time, the elastic force of the disc spring completely acts as the pressure of the brake pad on the brake disc. The friction force generated by the squeezing of the brake pads on both sides slows down the rotation of the brake disc, generating a braking torque, which is synchronized to the speed reduction of the drive wheel through the reducer connected to it, thereby achieving the purpose of braking;

[0022] Step 7: After braking, the brake control component is controlled to make the hydraulic power component pressurize the annular hydraulic cylinder again to compress the internal disc spring. The two brake pads leave the brake disc under the action of the disc spring, the braking torque disappears, and the vehicle continues to run normally;

[0023] Step 8: When parking brake is required, the brake control component is controlled to release the pressure on the annular hydraulic cylinder, which is consistent with the working principle of the above-mentioned service brake, generating a braking torque to achieve parking.

[0024] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of the principle of the present invention;

[0027] Figure 2 It is a schematic diagram of the structure of the hydraulic power assembly of the present invention;

[0028] Figure 3 It is a schematic diagram of the structure of the brake actuator assembly of the present invention;

[0029] Figure 4 It is a schematic diagram of the side structure of the brake actuator assembly of the present invention.

[0030] In the figure: 1. Mounting support; 2. Floating support; 3. Annular hydraulic cylinder; 4. Friction pair; 5. DC motor; 6. One-way valve; 7. Overflow valve; 8. Cartridge filter; 9. Pressure measuring joint; 10. Valve block; 11. Hydraulic pump; 12. Accumulator; 13. Accumulator pressure sensor; 14. Solenoid valve 1; 15. Solenoid valve 2; 16. Mode switching control valve; 17. Solenoid valve 3; 18. Pedal brake valve; 19. Manual parking valve; 20. One-way valve; 21. Electric proportional pressure reducing valve; 22. Leak-free direct-acting pressure reducing valve valve; 23. shuttle valve; 24. safety valve; 25. brake pressure sensor; 26. brake cylinder one; 27. brake cylinder two; 28. main oil circuit; 29. ​​branch oil circuit one; 30. branch oil circuit two; 31. branch oil circuit four; 32. branch oil circuit three; 33. branch oil circuit five; 34. branch oil circuit eight; 35. oil circuit ten; 36. branch oil circuit six; 37. branch oil circuit seven; 38. pressure relief oil circuit two; 39. pressure relief oil circuit one; 40. branch oil circuit nine; 41. fuel tank; 42. air filter; 43. temperature switch; 44. liquid level thermometer. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0032] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0033] The present invention provides the following embodiments

[0034] Example 1

[0035] The embodiment of the present invention provides a dual-mode hydraulic brake system, such as Figure 1 As shown, it includes a brake actuator component, a hydraulic power component and a brake control component. The hydraulic power component is connected to the brake actuator component through the brake control component. The brake control component includes a driving leak-free pressure-maintaining control oil circuit, a manned mode brake control oil circuit and an unmanned mode brake control oil circuit.

[0036] The beneficial effects of the above technical solution are:

[0037] The dual-mode hydraulic braking system of the present invention serves as a braking system for a vehicle, including two modes: manned braking and unmanned remote-controlled braking. The braking control component includes a manned mode braking control oil circuit and an unmanned mode braking control oil circuit, which can meet both manned driving and unmanned remote-controlled driving conditions, solving the technical problem of working conditions with only manned driving mode but no unmanned remote-controlled driving mode. The setting of the braking actuator component can increase the braking force, allowing the vehicle to perform slow and smooth deceleration braking, steep slope parking braking and long-term parking braking, solving the technical problem of long braking distance due to small braking force. The setting of the leakage-free pressure-maintaining control oil circuit during driving solves the technical problem of not being able to park for a long time due to hydraulic leakage.

[0038] Example 2

[0039] On the basis of Example 1, Figure 1-Figure 4 As shown, the brake actuator assembly includes a mounting support 1, a floating support 2 is fixedly mounted on the mounting support 1, an annular hydraulic cylinder 3 is slidably mounted on the floating support 2, the annular hydraulic cylinder 3 is fixedly connected to a friction pair 4, the friction pair 4 includes a brake pad and a brake disc, and the annular hydraulic cylinder 3 includes a brake cylinder 1 26 and a brake cylinder 2 27;

[0040] The hydraulic power assembly includes an oil tank 41, in which a liquid level thermometer 44 is installed. The liquid level thermometer 44 is electrically connected to the liquid temperature alarm through a temperature switch 43. An air filter 42 is installed on the oil tank 41. The oil tank 41 is connected to the hydraulic pump 11, and the hydraulic pump 11 is connected to the DC motor 5. The hydraulic pump 11 is connected to the one-way valve 6 through the main oil circuit 28, and a plug-in filter 8 is installed on the main oil circuit between the hydraulic pump 11 and the one-way valve 6. The main oil circuit 28 is connected to a pressure regulating oil circuit, and the pressure regulating oil circuit is connected to the overflow valve 7.

[0041] The beneficial effects of the above technical solution are:

[0042] The floating support 2 is connected to the mounting support 1 by bolts, and the rectangular spline cooperates with the spline of the annular hydraulic cylinder 3, so that the annular hydraulic cylinder 3 can slide axially along the floating support 2. The friction pair includes a brake pad and a brake disc. During normal driving, a certain pressure is increased in the annular hydraulic cylinder 3 to compress the disc spring in the annular hydraulic cylinder 3. At this time, a gap is generated between the brake pad and the brake disc, and no braking torque is generated. The vehicle can drive normally. When driving braking is required, the annular hydraulic cylinder 3 is depressurized. Under the action of the internal disc spring, the hydraulic cylinder piston extends out, pushing the brake pad to move axially until it contacts the brake disc. Under the reaction force of the brake disc, the brake pad drives the annular hydraulic cylinder to slide as a whole in the direction of the reaction force, and at the same time pulls the brake pad on the other side close to the brake disc. When the brake pads on both sides are attached to the brake disc at the same time, the elastic force of the disc spring completely acts as the pressure of the brake pad on the brake disc, and the brake disc is slowed down by the friction force generated by the squeezing of the brake pads on both sides.

[0043] The hydraulic power unit converts electrical energy into hydraulic energy, and the DC motor 5 drives the hydraulic pump 11 to work, sucking the oil in the oil tank 41 into the main oil circuit 28, passing through the plug-in filter 8 and the one-way valve 6, and then through the overflow valve 7 for pressure regulation, outputting clean high-pressure working oil. The liquid level and temperature gauge 44 is used to check the hydraulic oil level and temperature in the oil tank 41. The temperature switch 43 is a telecommunication switch for detecting the temperature of the hydraulic oil in the oil tank. When the oil temperature exceeds 80 degrees Celsius, the temperature switch 43 controls the liquid temperature alarm through the electrical controller.

[0044] Example 3

[0045] On the basis of Example 1, Figure 1-Figure 4 As shown, the brake control assembly also includes an accumulator energy storage control oil circuit, a driving non-leakage pressure maintenance control oil circuit, a mode switching control valve 16 and a safety valve 24. The accumulator energy storage control oil circuit includes an accumulator 12. The accumulator 12 is connected to the accumulator pressure sensor 13 and the pressure measuring joint 9 through the energy storage oil circuit. The energy storage oil circuit is connected to the main oil circuit 28.

[0046] The non-leakage pressure-maintaining control oil circuit for driving includes a solenoid valve 14, a port 1 of the solenoid valve 14 is connected to the main oil circuit 28, a port 2 of the solenoid valve 14 is connected to the branch oil circuit 29, a non-leakage direct-acting pressure reducing valve 22 is installed on the branch oil circuit 29, the branch oil circuit 29 is connected to the port 1 of the solenoid valve 2 15, the port 2 of the solenoid valve 2 15 is connected to the brake cylinder 1 26 and the brake cylinder 2 27 through the branch oil circuit 2 30, and a brake pressure sensor 25 is installed on the branch oil circuit 2 30;

[0047] The manned mode brake control oil circuit includes a pedal brake valve 18, a port 1 of the pedal brake valve 18 is connected to a port 1 of the mode switching control valve 16 through a branch oil circuit 32, a port 2 of the mode switching control valve 16 is connected to a port 3 of the solenoid valve 14 through a branch oil circuit 4 31, a port 2 of the pedal brake valve 18 is connected to a port 1 of the manual parking valve 19 through a branch oil circuit 5 33, and a port 2 of the manual parking valve 19 is connected to a branch oil circuit 8 34;

[0048] The unmanned mode brake control oil circuit includes a solenoid valve 3 17, a port 1 of the solenoid valve 3 17 is connected to a port 3 of the mode switching control valve 16 through a branch oil circuit 10 35, a port 2 of the solenoid valve 3 17 is connected to a port 1 of the electric proportional pressure reducing valve 21 through a branch oil circuit 6 36, the branch oil circuit 6 36 is connected to a side branch oil circuit, the side branch oil circuit is connected to a branch oil circuit 7 37, a check valve 20 is installed on the side branch oil circuit, a port 2 of the electric proportional pressure reducing valve 21 is connected to a port 1 of the shuttle valve 23 through a branch oil circuit 7 37, a port 2 of the shuttle valve 23 is connected to a branch oil circuit 8 34, and a port 3 of the shuttle valve 23 is connected to a port 3 of the solenoid valve 2 15 through a branch oil circuit 11;

[0049] Port three of solenoid valve three 17, pedal brake valve 18 and manual parking valve 19 are all connected to pressure relief oil circuit one 39 through pressure relief oil circuit two 38, pressure relief oil circuit one 39 is connected to the outlet of safety valve 24, the inlet of safety valve 24 is connected to branch oil circuit nine 40, and branch oil circuit nine 40 is connected to branch oil circuit two 30.

[0050] The beneficial effects of the above technical solution are:

[0051] Someone controls the braking mode. The driver can perform service braking by stepping on the pedal of the pedal brake valve 18. The greater the force of stepping on the pedal, the greater the braking torque output by the dual-mode hydraulic brake system of the present invention. At this time, the port 2 and the port 3 of the pedal brake valve 18 are connected, and the port 2 and the port 1 of the manual parking valve 19 are connected, so that the branch oil circuit 2 30, the branch oil circuit 11, the branch oil circuit 5 33, the branch oil circuit 8 34 and the pressure relief oil circuit 2 38 are connected, thereby unloading the oil in the annular hydraulic cylinder 3 to generate service braking. When the driver pulls up the handle of the manual parking valve 19, the dual-mode hydraulic brake system of the present invention will perform parking braking on the vehicle. At this time, the port 2 and the port 3 of the manual parking valve 19 are connected, so that the branch oil circuit 8 34 and the pressure relief oil circuit 2 38 are connected, thereby unloading the oil in the annular hydraulic cylinder 3 and generating parking brake; after the driver releases the handle of the manual parking valve 19, the parking brake is released, and the output of the braking torque stops when the driver releases the pedal of the pedal brake valve 18; the port 1 and the port 2 of the pedal brake valve 18 are connected, and the port 1 and the port 2 of the manual parking valve 19 are connected, so that the branch oil circuit 3 32, the branch oil circuit 5 33 and the branch oil circuit 8 34 are connected, thereby outputting high-pressure oil to the annular hydraulic cylinder 3 through the branch oil circuit 11 and the branch oil circuit 2 30 to release the parking brake;

[0052] In the unmanned remote control braking mode, the solenoid valve 3 17 is in the de-energized state, and the port 2 and the port 3 are connected. The oil pressure in the annular hydraulic cylinder 3 can be discharged through the solenoid valve 3 17 to produce the parking brake. In the energized state, the port 2 and the port 1 are connected, and the solenoid valve 3 17 can output high-pressure oil to the annular hydraulic cylinder 3 to release the parking brake. The electric proportional pressure reducing valve 21 can output the corresponding proportion of hydraulic pressure to the brake cylinder 1 26 and the brake cylinder 2 27. The one-way valve 20 is connected in parallel with the electric proportional pressure reducing valve 21, and its function is to ensure parking priority. Regardless of the electric proportional pressure reducing valve 21 in the unmanned mode, the service brake valve is in In any state, as long as the parking solenoid valve 3 17 is in the power-off parking state, the braking system will perform parking braking in the unmanned remote control mode; the electric proportional pressure reducing valve 21 is the driving brake control element in the unmanned remote control mode. Under the premise of no parking, the driver remotely controls the driving brake joystick to send a driving brake signal, the vehicle controller VCU receives the brake signal and outputs the brake signal to the electrical controller of the brake system, the electrical controller outputs a pressure control signal to the electric proportional pressure reducing valve 21, and the electric proportional pressure reducing valve 21 outputs a corresponding proportion of hydraulic pressure to the annular hydraulic cylinder 3, thereby controlling the magnitude of the driving braking torque;

[0053] When the mode switching control valve 16 is powered, it is in the unmanned remote control braking mode, at which time the port 3 of the mode switching control valve 16 is connected to the port 2, and when the mode switching control valve 16 is de-energized, it is in the manned control braking mode, at which time the port 1 of the mode switching control valve 16 is connected to the port 2; the shuttle valve 23 can automatically switch according to the manned control braking mode and the unmanned remote control braking mode; before switching from the manned control braking mode to the unmanned remote control mode, the handle of the manual parking valve 19 must be pulled up to put the manual parking valve 19 in the parking state, and the travel switch on the manual parking valve 19 sends a signal to the electrical controller of the braking system, so that the braking system meets the conditions for switching from the manned braking mode to the unmanned remote control mode;

[0054] The accumulator 12 is a component for storing high-pressure hydraulic oil, the accumulator pressure sensor 13 is a detection component for detecting the oil pressure in the accumulator 12, and the pressure measuring joint 9 is a detection interface for manually checking the oil pressure in the accumulator 12;

[0055] The driving non-leakage pressure-maintaining control oil circuit requires the hydraulic power component to output a certain amount of hydraulic pressure to the annular hydraulic cylinder 3 during normal driving, so that the annular hydraulic cylinder 3 offsets the braking force output by the brake spring and releases the brake device. Since the driving state is normal and needs to be maintained for a long time, in order to reduce the leakage of hydraulic oil through the pedal brake valve 18 and reduce the frequency of oil replenishment of the accumulator 12, the driving non-leakage pressure-maintaining control oil circuit is designed. When the accumulator 12 is replenished with oil, the port 1 of the solenoid valve 14 is connected to the port 2, and the port 1 of the solenoid valve 2 15 is connected to the port 2. At this time, a certain amount of hydraulic pressure is output to the annular hydraulic cylinder 3 through the branch oil circuit 1 29, which meets the requirement that the accumulator 12 does not need to be pressurized for more than 2 hours under the driving state;

[0056] When the manned mode brake control oil circuit and the unmanned mode brake control oil circuit are working, the port 1 and the port 3 of the solenoid valve 14 are connected, and the port 2 and the port 3 of the solenoid valve 2 15 are connected;

[0057] The function of the safety valve 24 is to ensure that the dual-mode hydraulic brake system of the present invention does not have pressure overshoot in an abnormal state, thereby causing leakage in the annular hydraulic cylinder 3 and various components in the brake control assembly.

[0058] The function of the brake pressure sensor 25 is to monitor the hydraulic pressure in the annular hydraulic cylinder 3 and output a pressure signal to the electrical controller;

[0059] The valve block 10 is the main body of several oil circuits in the brake control assembly. Several valves in the brake control assembly are installed on the valve block 10. The oil passages of several oil circuits in the brake control assembly are designed inside the valve block 10 to form an integrated control valve group. The valve block 10 has the advantages of small size, light weight and few leakage points.

[0060] The electrical controller is the electrical control part of the dual-mode hydraulic brake system. Its function is to receive feedback information from the driver's braking operation, such as the feedback signals of the travel switches on the temperature switch 43, the accumulator pressure sensor 13, the brake pressure sensor 25, the pedal brake valve 18 and the manual parking valve 19; monitor the hydraulic system to execute according to the driver's intention, and send fault information when a fault occurs in the brake system; control the power unit and the accumulator energy storage control oil circuit to output the pressure oil source at the set pressure and store it in the accumulator 12, receive the command information issued by the on-board VCU, and feedback the braking data and information of the braking system during operation to the VCU. The focus of this application is to protect the components in the brake actuator, hydraulic power component and brake control component and their connection relationship. Regarding the electrical control method and valve block 10 of the electrical controller, both adopt the existing technology, and the present invention will not repeat them.

[0061] Example 4

[0062] On the basis of Example 3, Figure 1 As shown, it also includes an automatic pressure replenishment method for the accumulator 12, comprising the following steps:

[0063] Step 1: Install a flow rate sensor at the connection point between the accumulator 12 and the energy storage oil circuit to detect the oil outlet flow rate of the accumulator 12;

[0064] Step 2: electrically connect the electrical controller to the flow rate sensor and the timer, the timer is used to detect the working time when the detection value of the flow rate sensor is not 0;

[0065] Step 3: The electrical controller calculates the theoretical time required for the accumulator 12 to replenish the pressure according to the detection value of the flow rate sensor and formula (1);

[0066] ; (1)

[0067] in, is the theoretical time required for the accumulator 12 to replenish pressure, is the oil storage capacity of the accumulator 12, is the working volume of the annular hydraulic cylinder 3, is the pre-charge pressure of the accumulator 12, is the effective diameter of the safety valve; is the maximum detection value of the accumulator pressure sensor 13, is the stiffness coefficient of the brake spring, is the extension and contraction distance of the brake spring, is the flow area of ​​the energy storage oil circuit, is the flow velocity of the energy storage oil circuit, is the value of pi, which is 3.14;

[0068] Step 4: When the timer detects that the working time of the accumulator 12 is the same as the theoretical time required for the accumulator 12 to replenish pressure calculated in step 3, the timer controls the accumulator 12 to automatically replenish pressure through the electrical controller.

[0069] The beneficial effects of the above technical solution are:

[0070] A flow rate sensor is installed at the connection point between the accumulator 12 and the energy storage oil circuit to detect the oil outlet flow rate of the accumulator 12; an electrical controller is electrically connected to the flow rate sensor and a timer, and the timer is used to detect the working time when the detection value of the flow rate sensor is not 0; the electrical controller calculates the theoretical time required for the accumulator 12 to replenish the pressure according to the detection value of the flow rate sensor and formula (1); when the timer detects that the working time of the accumulator 12 is the same as the theoretical time required for the accumulator 12 to replenish the pressure calculated in step 3, the timer controls the accumulator 12 to automatically replenish the pressure through the electrical controller, thereby ensuring the normal operation of the accumulator energy storage control oil circuit and avoiding insufficient liquid pressure in the annular hydraulic cylinder 3, which cannot offset the output braking force of the brake spring.

[0071] Example 5

[0072] Based on Embodiment 4, a control method for a dual-mode hydraulic brake system is provided. Figure 1-Figure 2 As shown, the following steps are included:

[0073] Step 5: During normal driving, the hydraulic power assembly and the brake control assembly increase a certain pressure in the annular hydraulic cylinder 3 to compress the disc spring inside the annular hydraulic cylinder 3. At this time, a gap is generated between the brake pad and the brake disc, and no braking torque is generated, so the vehicle can drive normally.

[0074] Step 6: When the vehicle needs to brake, the brake control component is controlled to release the pressure on the annular hydraulic cylinder 3. Under the action of the internal disc spring, the annular hydraulic cylinder 3 extends, pushing the brake pad to move axially until it contacts the brake disc. Under the reaction force of the brake disc, the brake pad drives the annular hydraulic cylinder to slide in the direction of the reaction force as a whole, and at the same time pulls the brake pad on the other side close to the brake disc. When the brake pads on both sides are attached to the brake disc at the same time, the elastic force of the disc spring completely acts as the pressure of the brake pad on the brake disc. The friction force generated by the squeezing of the brake pads on both sides slows down the rotation of the brake disc, generating a braking torque, which is synchronized to the speed reduction of the driving wheel through the reducer connected thereto, thereby achieving the braking purpose;

[0075] Step 7: After braking, the brake control component is controlled to make the hydraulic power component pressurize the annular hydraulic cylinder 3 again to compress the internal disc spring. The two brake pads leave the brake disc under the action of the disc spring, the braking torque disappears, and the vehicle continues to run normally.

[0076] Step 8: When parking brake is required, the brake control component is controlled to release the pressure on the annular hydraulic cylinder 3, which is consistent with the working principle of the above-mentioned service brake, generates a braking torque, and achieves parking.

[0077] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A dual-mode hydraulic brake system, comprising a brake actuator assembly, a hydraulic power assembly and a brake control assembly, wherein the hydraulic power assembly is connected to the brake actuator assembly through the brake control assembly, and the brake control assembly comprises a driving non-leakage pressure-maintaining control oil circuit, a manned mode brake control oil circuit and an unmanned mode brake control oil circuit; in, The hydraulic power assembly comprises an oil tank (41), the oil tank (41) is connected to a hydraulic pump (11), the hydraulic pump (11) is connected to a DC motor (5), and the hydraulic pump (11) is connected to a first one-way valve (6) via a main oil circuit (28); The brake control component comprises an accumulator energy storage control oil circuit, a mode switching control valve (16) and a safety valve (24); the accumulator energy storage control oil circuit comprises an accumulator (12); the accumulator (12) is connected to an accumulator pressure sensor (13) and a pressure measuring joint (9) via the energy storage control oil circuit; and the energy storage control oil circuit is connected to a main oil circuit (28); The non-leakage driving pressure-maintaining control oil circuit includes a solenoid valve (14), a port (1) of the solenoid valve (14) is connected to a main oil circuit (28), a port (2) of the solenoid valve (14) is connected to a branch oil circuit (29), a non-leakage direct-acting pressure reducing valve (22) is installed on the branch oil circuit (29), the branch oil circuit (29) is connected to a port (1) of the solenoid valve (15), a port (2) of the solenoid valve (15) is connected to a brake cylinder (26) and a brake cylinder (27) through a branch oil circuit (30), and a brake pressure sensor (25) is installed on the branch oil circuit (30); The manned mode brake control oil circuit includes a pedal brake valve (18), a port 1 of the pedal brake valve (18) is connected to a port 1 of the mode switching control valve (16) through a branch oil circuit 3 (32), a port 2 of the mode switching control valve (16) is connected to a port 3 of the solenoid valve 1 (14) through a branch oil circuit 4 (31), a port 2 of the pedal brake valve (18) is connected to a port 1 of the manual parking valve (19) through a branch oil circuit 5 (33), and a port 2 of the manual parking valve (19) is connected to a branch oil circuit 8 (34); The unmanned mode brake control oil circuit comprises a solenoid valve 3 (17), a port 1 of the solenoid valve 3 (17) is connected to a port 3 of the mode switching control valve (16) through a branch oil circuit 10 (35), a port 2 of the solenoid valve 3 (17) is connected to a port 1 of the electric proportional pressure reducing valve (21) through a branch oil circuit 6 (36), the branch oil circuit 6 (36) is connected to a side branch oil circuit, the side branch oil circuit is connected to a branch oil circuit 7 (37), a second non-return valve (20) is installed on the side branch oil circuit, a port 2 of the electric proportional pressure reducing valve (21) is connected to a port 1 of the shuttle valve (23) through a branch oil circuit 7 (37), a port 2 of the shuttle valve (23) is connected to a branch oil circuit 8 (34), and a port 3 of the shuttle valve (23) is connected to a port 3 of the solenoid valve 2 (15) through a branch oil circuit 11; Among them, the ports 3 of the solenoid valve 3 (17), the pedal brake valve (18) and the manual parking valve (19) are all connected to the pressure relief oil circuit 1 (39) through the pressure relief oil circuit 2 (38), the pressure relief oil circuit 1 (39) is connected to the outlet of the safety valve (24), the inlet of the safety valve (24) is connected to the branch oil circuit 9 (40), and the branch oil circuit 9 (40) is connected to the branch oil circuit 2 (30).

2. A dual-mode hydraulic brake system according to claim 1, characterized in that: The brake actuator assembly comprises a mounting support (1), a floating support (2) is fixedly mounted on the mounting support (1), an annular hydraulic cylinder (3) is slidably mounted on the floating support (2), the annular hydraulic cylinder (3) is fixedly connected to a friction pair (4), and the friction pair (4) comprises a brake pad and a brake disc.

3. A dual-mode hydraulic brake system according to claim 2, characterized in that: A liquid level thermometer (44) is installed in the oil tank (41), and the liquid level thermometer (44) is electrically connected to the liquid temperature alarm via a temperature switch (43). An air filter (42) is installed on the oil tank (41), and a plug-in filter (8) is installed on the main oil circuit between the hydraulic pump (11) and the first one-way valve (6). A pressure regulating oil circuit is connected to the main oil circuit (28), and the pressure regulating oil circuit is connected to the overflow valve (7).

4. A control method for a dual-mode hydraulic brake system according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: During normal driving, the hydraulic power assembly and the brake control assembly increase a certain pressure in the annular hydraulic cylinder (3) of the brake actuator assembly to compress the disc spring inside the annular hydraulic cylinder (3). At this time, a gap is generated between the brake pad and the brake disc of the brake actuator assembly, and no braking torque is generated, so the vehicle can drive normally. Step 2: When the vehicle needs to brake, the brake control component is controlled to release the pressure on the annular hydraulic cylinder (3). Under the action of the internal disc spring, the annular hydraulic cylinder (3) extends, pushing the brake pad to move axially until it contacts the brake disc. Under the reaction force of the brake disc, the brake pad drives the annular hydraulic cylinder as a whole to slide in the direction of the reaction force, and at the same time pulls the brake pad on the other side close to the brake disc. When the brake pads on both sides are attached to the brake disc at the same time, the elastic force of the disc spring completely acts as the pressure of the brake pad on the brake disc. The friction force generated by the squeezing of the brake pads on both sides slows down the rotation of the brake disc, generating a braking torque, which is synchronized with the reducer connected to it until the speed of the driving wheel is reduced, thereby achieving the purpose of braking; Step 3: After braking is completed, the brake control component is controlled to make the hydraulic power component pressurize the annular hydraulic cylinder (3) again to compress the internal disc spring. The two brake pads leave the brake disc under the action of the disc spring, the braking torque disappears, and the vehicle continues to run normally. Step 4: When parking brake is required, the brake control component is controlled to release the pressure of the annular hydraulic cylinder (3), which is consistent with the working principle of the above-mentioned service brake, generates a braking torque, and achieves parking.

5. A control method according to claim 4, characterized in that: Also included is an automatic pressure replenishment method for the accumulator (12): Step 5: Install a flow rate sensor at the connection point between the accumulator (12) and the energy storage control oil circuit to detect the oil outlet flow rate of the accumulator (12); Step 6: The controller is electrically connected to the flow rate sensor and the timer, and the timer is used to detect the working time when the detection value of the flow rate sensor is not 0; Step 7: The controller calculates the theoretical time required for the accumulator (12) to replenish the pressure according to the detection value of the flow rate sensor and formula (1); ； （1） in, is the theoretical time required for the accumulator (12) to replenish pressure, is the oil storage capacity of the accumulator (12), is the working volume of the annular hydraulic cylinder (3), is the pre-charge pressure of the accumulator (12), is the effective diameter of the safety valve; is the maximum detection value of the accumulator pressure sensor (13), is the spring constant of the disc spring, is the expansion and contraction distance of the disc spring, To control the flow area of ​​the oil circuit for energy storage, To store energy and control the flow rate of the oil circuit, is the value of pi, which is 3.14; Step 8: When the timer detects that the working time of the accumulator (12) is the same as the theoretical time required for the accumulator (12) to replenish pressure calculated in step 7, the timer controls the accumulator (12) to automatically replenish pressure through the controller.

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