Drive-by-wire hydraulic system for driving and parking braking of vehicle

Abstract

The invention discloses a drive-by-wire hydraulic system for driving and parking braking of a vehicle. The drive-by-wire hydraulic system comprises a hydraulic booster, a power source assembly, an electronic control hydraulic valve, an electronic parking cylinder, a front brake caliper and a rear brake caliper, the electronic control hydraulic valve is used for hydraulically controlling the front brake caliper and the rear brake caliper, and the electronic parking cylinder is used for parking brake; in conclusion, hydraulic output is accurately controlled by adopting the servo brushless motor or the stepping motor, and the requirement of a large-tonnage commercial vehicle for high braking force is met; the electric control hydraulic valve is combined with the feedback unit and the sensor to monitor and adjust the brake pressure in real time, so that the accuracy and the response speed of service brake are ensured; in addition, due to the design of the electronic parking cylinder, the complexity of the system is simplified, the production cost is reduced, stability can be automatically kept in the parking state, and the parking safety is improved. The whole system has the characteristics of high efficiency and reliability, is especially suitable for unmanned driving scenes, and provides a solid guarantee for safe operation of commercial vehicles.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle braking, and in particular relates to a wire-controlled hydraulic system for driving and parking brakes of a vehicle. Background Art

[0002] With the rapid development of autonomous driving technology, vehicle braking systems, one of its core technologies, have also undergone significant changes. Traditional vehicle braking systems rely on vacuum boosters for brake assistance. However, with the growing demand for intelligent control, modern vehicles are gradually adopting more advanced electronically controlled hydraulic boosters. These new braking systems can autonomously adjust the hydraulic pressure within the wheel cylinders based on information from various sensors, thereby achieving more precise and reliable braking. The electronically controlled hydraulic brake systems currently used in most passenger cars typically control the pressure increase and reduction process through a servo motor driving the brake master cylinder or solenoid valve, achieving automatic adjustment of the brake wheel cylinder pressure.

[0003] While existing technologies have achieved considerable success in the passenger car sector, when it comes to large-tonnage commercial vehicles, existing electronically controlled hydraulic brake systems often fail to provide sufficient hydraulic support to meet the higher braking force requirements. Therefore, a completely new brake hydraulic control system design is needed for large-tonnage commercial vehicles. Summary of the Invention

[0004] The present invention aims to provide a wire-controlled hydraulic system for vehicle driving and parking brakes, which solves the technical problem that the existing electronically controlled hydraulic brake devices of large-tonnage commercial vehicles often cannot provide sufficient hydraulic support to meet their higher braking force requirements.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: A wire-controlled hydraulic system for driving and parking brakes of a vehicle, comprising a hydraulic booster, a power source assembly, an electronically controlled hydraulic valve, an electronic parking cylinder, a front brake caliper, and a rear brake caliper; The electronically controlled hydraulic valve is used to hydraulically control the front and rear brake calipers, the electronic parking cylinder is used for parking brakes, the hydraulic booster includes an oil pot and a controller, the oil pot provides brake fluid for the power source assembly, the oil pot is provided with an oil pot return port and an oil pot oil outlet, the controller is used to control the operation of the power source assembly, the electronically controlled hydraulic valve and the electronic parking cylinder, the hydraulic booster is also provided with a master pump rear circuit interface, a high-pressure oil inlet and a high-pressure oil outlet; the power source assembly is provided with an oil inlet, a main high-pressure port and a secondary high-pressure port, the main high-pressure port is connected to the high-pressure oil inlet through a first high-pressure pipeline, and the oil inlet is connected to the oil pot outlet through an oil inlet pipeline; The electrically controlled hydraulic valve includes a control valve unit, a feedback unit and a motor unit; the control valve unit includes a control valve block, a feedback chamber and a sliding valve chamber are provided in the control valve block, a sliding valve is provided in the sliding valve chamber, the sliding valve includes a valve sleeve and a valve core, three first sealing rings are provided between the outer wall of the valve sleeve and the inner wall of the sliding valve chamber, a pressure relief valve port and a pressure relief valve port are also provided on the valve sleeve, the pressure relief valve port and the pressure relief valve port are both provided along the radial direction of the valve sleeve, the valve sleeve has a valve sleeve through hole, the valve core is located in the valve sleeve through hole, and the valve core and the valve sleeve are in sliding fit, a first small-diameter channel is provided in the valve core, an annular oil groove is provided on the middle outer wall of the valve core, the first small-diameter channel is connected between the feedback chamber and the annular oil groove, and when the valve core moves in the valve sleeve, the annular oil groove can be in contact with the feedback chamber. The pressure relief valve port or the pressure relief valve port is connected; one end of the valve core extends into the feedback chamber and is provided with a retaining ring at the end; a return spring is provided in the feedback chamber, and the two ends of the return spring respectively abut against the end of the feedback chamber and the retaining ring; the control valve block is also provided with a hydraulic sensing interface, a pressure relief interface, a working interface, a circuit master cylinder interface and a high-pressure oil inlet interface, the hydraulic sensing interface is connected with the feedback chamber, and a first hydraulic sensor is installed on the hydraulic sensing interface, and the control valve block is also provided with a second small-diameter channel, and the feedback chamber is sequentially connected to the working interface and the circuit master cylinder interface through the second small-diameter channel, and a shuttle valve is provided on the second small-diameter channel; the pressure relief interface is connected with the pressure relief valve port, and the high-pressure oil inlet interface is connected with the pressure relief valve port; The pressure relief interface is connected to the oil return port of the oil tank of the hydraulic booster through the first oil return line. The working interface is connected to the front brake caliper and the rear brake caliper through the front brake line and the rear brake line respectively. The circuit master cylinder interface is connected to the rear circuit interface of the master pump of the hydraulic booster through the rear line. The high-pressure oil inlet interface is connected to the high-pressure oil outlet of the hydraulic booster through the second high-pressure line. The feedback unit includes a feedback block, which is arranged at the end of the control valve block and uses a second sealing ring for end face sealing. A normal pressure chamber and a third small-diameter channel are provided in the feedback block. The third small-diameter channel is connected to the sliding valve chamber. A piston, a push rod and a feedback spring are provided in the normal pressure chamber. The piston can slide in the axial direction. Two third sealing rings are provided on the inner wall of the normal pressure chamber. The third sealing rings are used to seal the gap between the piston and the normal pressure chamber. A radial oil drain hole is provided on the feedback block. The radial oil drain hole is connected to the normal pressure chamber between the two sealing rings. The feedback spring is located between the push rod and the piston. One end of the push rod is located in the third small-diameter channel, and the end of the push rod abuts against the end of the valve core. The motor unit is arranged on the end surface of the feedback block, and the motor unit is used to push the piston to move forward and backward; The electronic parking cylinder includes a parking rod, a parking valve body and a housing, the parking valve body is installed at the end of the housing, a high-pressure chamber is provided in the parking valve body, the end of the high-pressure chamber is open, a high-pressure piston is provided in the high-pressure chamber, the high-pressure piston can slide in the high-pressure chamber, and the other end of the high-pressure piston extends into the housing, a parking spring and a spring seat are provided in the housing, a guide ring is provided on the outer periphery of the spring seat, the spring seat is slidably installed in the housing through the guide ring, the end of the high-pressure piston is connected to the spring seat, the parking spring is in contact with the inner wall of the housing and the spring seat, the parking rod is inserted through the end of the housing, the inner end of the parking rod is connected to the spring seat, the outer end of the parking rod is threadedly connected to a pull head, the parking hook coincides with the axis of the high-pressure piston, and the pull head is connected to the rear brake caliper through the parking cable; A high-pressure interface and an oil outlet nozzle are provided on the parking valve body. The high-pressure interface is connected to the secondary high-pressure port of the power source assembly through a third high-pressure pipeline, and the oil outlet nozzle is connected to the oil return port of the oil tank of the hydraulic booster through a second return oil pipeline; wherein a fourth small-diameter channel is provided in the parking valve body, and the high-pressure chamber is connected to the high-pressure interface and the oil outlet nozzle respectively through the fourth small-diameter channel, and a first stop valve, an electromagnetic normally closed valve, a second hydraulic sensor, two groups of electromagnetic normally open valves and a second stop valve are also installed on the parking valve body, wherein the first stop valve, the electromagnetic normally closed valve and the second hydraulic sensor are arranged on the connecting channel between the high-pressure chamber and the high-pressure interface, and the two groups of electromagnetic normally open valves and the second stop valve are arranged on the connecting channel between the high-pressure chamber and the oil outlet nozzle.

[0006] Furthermore, the motor unit is a linear servo motor, and the screw shaft of the linear servo motor is threadedly connected to the end of the piston.

[0007] Furthermore, a sliding sleeve is fixed in the normal pressure chamber, a key groove is provided on the inner wall of the sliding sleeve, a sliding key is fixed on the outer wall of the piston, and the sliding key can slide in the key groove of the sliding sleeve along the axial direction.

[0008] Compared with the prior art, the present invention has the following beneficial effects: (1) The hydraulic control valve of the present invention adopts a valve core displacement control method in which a linear servo motor drives a feedback spring, and combines a composite balancing mechanism of a hydraulic feedback chamber and a nonlinear feedback spring to achieve high-precision closed-loop control of the brake pressure, meeting the dynamic response requirements of heavy vehicles under continuous braking conditions; (2) The present invention uses a common power source assembly for the service brake and parking brake systems, and adopts a dual-mode parking solution with a parallel solenoid valve group and a mechanical emergency unlocking. This reduces the number of hydraulic components by more than 30% while ensuring parking reliability, thereby reducing system complexity and manufacturing costs. (3) The innovative design of the sliding valve assembly axial sealing structure and dual redundant sealing feedback pistons, combined with real-time monitoring of multi-stage hydraulic circuit pressure, significantly improves the sealing durability of the system under harsh working conditions such as vibration and alternating high and low temperatures, and extends the life of key components to more than 150,000 cycles; (4) The dynamic compensation mechanism for hill parking based on hydraulic-mechanical coupling can identify and compensate for pressure fluctuations caused by vehicle inertia in a short period of time through the coordinated control of the electronically controlled hydraulic valve and the electronic parking cylinder, completely eliminating the risk of the vehicle slipping when parking on a heavy-loaded slope. Its comprehensive performance is superior to the current industry standard for commercial vehicle braking systems.

[0009] In summary, the present invention effectively resolves the contradiction between high hydraulic pressure requirements and cost control in the braking system of large-tonnage commercial vehicles through the three-level linkage control architecture of the electronically controlled hydraulic valve and the dual-circuit redundant design of the electronic parking cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] 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: Figure 1 The present invention is a structural schematic diagram of a wire-controlled hydraulic system for driving and parking brakes of a vehicle.

[0011] Figure 2 It is a structural diagram of an electronically controlled hydraulic valve; Figure 3 It is a connection diagram of the control valve unit and the feedback unit; Figure 4 It is a structural diagram of a hydraulic booster; Figure 5 is a first cross-sectional view of the electronic parking cylinder; Figure 6 is a second cross-sectional view of the electronic parking cylinder; Figure 7 This is the third cross-sectional view of the electronic parking cylinder. DETAILED DESCRIPTION

[0012] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0013] The present invention is described in further detail below with reference to the examples.

[0014] like Figure 1-7 As shown, a specific embodiment of a wire-controlled hydraulic system for driving and parking brakes of a vehicle provided by the present invention is as follows: A wire-controlled hydraulic system for driving and parking brakes of a vehicle, comprising a hydraulic booster 1, a power source assembly 2, an electronically controlled hydraulic valve 3, an electronic parking cylinder 4, a front brake caliper 5, and a rear brake caliper 6; The electronically controlled hydraulic valve 3 is used to hydraulically control the front brake caliper 5 and the rear brake caliper 6, while the electronic parking cylinder 4 is responsible for parking brakes. The hydraulic booster 1 includes an oil pot 7 and a controller 8. The oil pot 7 provides brake fluid for the power source assembly 2. The oil pot 7 is provided with an oil pot return port 9 and an oil pot oil outlet port 10. The controller 8 is used to control the operation of the power source assembly 2, the electronically controlled hydraulic valve 3 and the electronic parking cylinder 4. The hydraulic booster 1 is also equipped with a master cylinder rear circuit interface 11, a high-pressure oil inlet port 12 and a high-pressure oil outlet port 13; the power source assembly 2 is provided with an oil inlet port 80, a main high-pressure port 14 and a secondary high-pressure port 15. The main high-pressure port 14 is connected to the high-pressure oil inlet port 12 through a first high-pressure pipeline 16, and the oil inlet 80 is connected to the oil pot oil outlet port 10 through an oil inlet pipeline 81; like Figure 2 and Figure 3 As shown, the electronically controlled hydraulic valve 3 includes a control valve unit, a feedback unit and a motor unit; the control valve unit includes a control valve block 20, a feedback chamber 21 and a slide valve chamber 22 are provided in the control valve block 20, a slide valve is provided in the slide valve chamber 22, and the slide valve includes a valve sleeve 24 and a valve core 25. Three first sealing rings 26 are provided between the outer wall of the valve sleeve 24 and the inner wall of the slide valve chamber 22. The valve sleeve 24 is also provided with a pressure relief valve port 27 and a pressure relief valve port 28. The pressure relief valve port 2 7 and the pressure relief valve port 28 are arranged along the radial direction of the valve sleeve 24. The valve sleeve 24 has a valve sleeve through hole. The valve core 25 is located in the valve sleeve through hole, and the valve core 25 and the valve sleeve 24 are in sliding cooperation. A first small-diameter channel 30 is opened in the valve core 25. An annular oil groove 31 is provided on the middle outer wall of the valve core 25. The first small-diameter channel 30 is connected between the feedback chamber 21 and the annular oil groove 31. When the valve core 25 moves in the valve sleeve 24, the annular oil groove 31 can be connected to the feedback chamber 21. The pressure relief valve port 27 or the pressure relief valve port 28 is connected; one end of the valve core 25 extends into the feedback chamber 21 and is provided with a retaining ring 32 at the end; a return spring 33 is provided in the feedback chamber 21, and the two ends of the return spring 33 respectively abut against the end of the feedback chamber 21 and the retaining ring 32; the control valve block 20 is also provided with a hydraulic sensing interface 34, a pressure relief interface 35, a working interface 36, a circuit master cylinder interface 37 and a high-pressure oil inlet interface 38, the hydraulic sensing interface 34 is connected to the feedback chamber 21, and a first hydraulic sensor 39 is installed on the hydraulic sensing interface 34, and the control valve block 20 is also provided with a second small-diameter channel 40, the feedback chamber 21 is connected to the working interface 36 and the circuit master cylinder interface 37 in sequence through the second small-diameter channel 40, and a shuttle valve 41 is provided on the second small-diameter channel 40; the pressure relief interface 35 is connected to the pressure relief valve port 28, and the high-pressure oil inlet interface 38 is connected to the pressure relief valve port 27; The pressure relief interface 35 is connected to the oil return port 9 of the oil tank of the hydraulic booster 1 through a first oil return line 42. The working interface 36 is connected to the front brake caliper 5 and the rear brake caliper 6 through a front brake line 43 and a rear brake line 44 respectively. The circuit master cylinder interface 37 is connected to the master cylinder rear circuit interface 11 of the hydraulic booster 1 through a rear line 45. The high-pressure oil inlet interface 38 is connected to the high-pressure oil outlet 13 of the hydraulic booster 1 through a second high-pressure line 46. The feedback unit includes a feedback block 47, which is arranged at the end of the control valve block 20 and is sealed with a second sealing ring 48. A normal pressure chamber 49 and a third small diameter channel 50 are provided in the feedback block 47. The third small diameter channel 50 is connected to the slide valve chamber 22. A piston 51, a push rod 52 and a feedback spring 53 are provided in the normal pressure chamber 49. The piston 51 can slide in the axial direction. Specifically, a sliding sleeve 77 is fixed in the normal pressure chamber 49. The inner wall of the sliding sleeve 77 is provided with a key groove. The outer wall of the piston 51 is fixed with a sliding key 7 9, the sliding key 79 can slide axially within the keyway of the sliding sleeve 77. Two third sealing rings 100 are provided on the inner wall of the normal pressure chamber 49. The third sealing rings 100 are used to seal the gap between the piston 51 and the normal pressure chamber 49. The feedback block 47 is provided with a radial oil drain hole 54, which communicates with the normal pressure chamber 49 between the two sealing rings. The feedback spring 53 is located between the push rod 52 and the piston 51. One end of the push rod 52 is located in the third small-diameter channel 50, and the end of the push rod abuts the end of the valve core 25. The motor unit is arranged on the end surface of the feedback block 47 , and is used to push the piston 51 to move forward and backward. The motor unit is a linear servo motor 75 , and the screw shaft 76 of the linear servo motor 75 is threadedly connected to the end of the piston 51 .

[0015] like Figure 5-7 The electronic parking cylinder 4 includes a parking rod 55, a parking valve body 56 and a housing 57. The parking valve body 56 is installed at the end of the housing 57. A high-pressure chamber 58 is provided in the parking valve body 56. The end of the high-pressure chamber 58 is open. A high-pressure piston 59 is provided in the high-pressure chamber 58. The high-pressure piston 59 can slide in the high-pressure chamber 58. The other end of the high-pressure piston 59 extends into the housing 57. A parking spring 60 and a spring seat 61 are provided in the housing 57. The outer periphery of the spring seat 61 is provided with a guide ring. 62, a spring seat 61 is slidably mounted in the housing 57 via a guide ring 62, the end of the high-pressure piston 59 is connected to the spring seat 61, the parking spring 60 abuts against the inner wall of the housing 57 and the spring seat 61, the parking rod 55 is inserted through the end of the housing 57, the inner end of the parking rod 55 is connected to the spring seat 61, the outer end of the parking rod 55 is threadedly connected to a pull head 63, the parking hook coincides with the axis of the high-pressure piston 59, and the pull head 63 is connected to the rear brake caliper 6 via a parking cable 64; A high-pressure interface 65 and an oil outlet nozzle 66 are provided on the parking valve body 56. The high-pressure interface 65 is connected to the secondary high-pressure port 15 of the power source assembly 2 through a third high-pressure pipeline 67, and the oil outlet nozzle 66 is connected to the oil return port 9 of the hydraulic booster 1 through a second oil return pipeline 68; wherein a fourth small-diameter channel 69 is provided in the parking valve body 56, and the high-pressure chamber 58 is connected to the high-pressure interface 65 and the oil outlet nozzle 66 respectively through the fourth small-diameter channel 69. A first stop valve 7 is also installed on the parking valve body 56. 0, electromagnetic normally closed valve 71, second hydraulic sensor 72, two groups of electromagnetic normally open valves 73 and second stop valve 74, wherein the first stop valve 70, the electromagnetic normally closed valve 71, and the second hydraulic sensor 72 are arranged on the connecting channel between the high-pressure chamber 58 and the high-pressure interface 65, the first stop valve 70 and the electromagnetic normally closed valve 71 are in parallel, the two groups of electromagnetic normally open valves 73 and the second stop valve 74 are arranged on the connecting channel between the high-pressure chamber 58 and the oil outlet nozzle 66, and the two groups of electromagnetic normally open valves 73 are in parallel.

[0016] In this embodiment, when the electronically controlled hydraulic valve 3 is not in operation, under the elastic force of the return spring 33, the valve core 25 is in the initial position, the annular oil groove 31 is not connected to the pressure relief valve port 27, the pressure relief valve port 27 is in a closed state, and the pipeline of the power source assembly 2 is disconnected from the brake circuit. At this time, after the driver steps on the brake pedal, the brake fluid in the hydraulic booster 1 flows into the circuit master cylinder interface 37 of the electronically controlled hydraulic valve 3 through the master cylinder rear circuit interface 11 and the rear pipeline 45, and then enters the shuttle valve 41 through the circuit master cylinder interface 37, and is pressed into the rear brake caliper 6 and the front brake caliper 5 through the working interface 36 to apply the rear brake; when the electronically controlled hydraulic valve 3 is in operation, the controller 8 controls the linear servo motor 75 to start, and the linear servo motor 7 5 drives the screw shaft 76 to move linearly and push the piston 51 forward. The piston 51 continues to push the abutting feedback spring 53, and the feedback spring 53 drives the push rod 52 and the valve core 25 to move forward. When the valve core 25 moves forward, the annular oil passage connects with the pressure relief valve port 27 and is offset from the pressure relief valve port 28. At this time, the pressure relief valve port 28 is closed and the pressure relief valve port 27 is opened. The high-pressure brake fluid in the power source assembly 2 enters the hydraulic booster 1 through the main high-pressure port 14, the first high-pressure pipeline 16, and the high-pressure oil inlet port 12, and then enters the high-pressure oil inlet port 38 of the electronically controlled hydraulic valve 3 through the high-pressure oil outlet port 13 and the second high-pressure pipeline 46. The high-pressure brake fluid entering through the high-pressure oil inlet port 38 then passes through the pressure relief valve 28 in sequence. The fluid flows through the shuttle valve 41 through the port 27, the first small-diameter channel 30, the feedback chamber 21, and the second small-diameter channel 40. The fluid cuts off the circuit between the master cylinder and the caliper under the action of the hydraulic pressure, and finally flows into the rear brake caliper 6 and the front brake caliper 5. At the same time, under the action of the hydraulic pressure in the feedback chamber 21, the valve core 25 pushes the push rod 52 in the opposite direction and compresses the feedback spring 53. Under the continuous action of the hydraulic pressure, the pressure relief valve port 27 is closed again. At this time, the fluid pressure in the feedback chamber 21 is balanced with the elastic force of the feedback spring 53. Since the feedback chamber 21 is connected to the circuits of the front brake caliper 5 and the rear brake caliper 6, the fluid pressure in the caliper circuit is also equal to the elastic force of the feedback spring 53. At the same time, the first hydraulic sensor 39 receives the hydraulic information It is transmitted back to the controller 8, and the controller 8 monitors the hydraulic pressure of the brake caliper circuit in real time; when the controller 8 accepts the vehicle's request to continue to increase the brake hydraulic pressure, the linear servo motor 75 pushes the valve core 25 again, so that the pressure relief valve port 27 is opened again, until the output hydraulic value of the first hydraulic sensor 39 is equal to the requested hydraulic value, and the linear servo motor 75 stops working; when the controller 8 accepts the vehicle's request to reduce the brake hydraulic pressure, the linear servo motor 75 rotates in the opposite direction, and the pressure relief valve port 28 is opened under the action of the hydraulic pressure and the return spring 33, and the brake fluid in the caliper flows back to the oil tank 7 through the pressure relief valve port 28, the pressure relief interface 35, the first return oil pipeline 42, and the oil tank return port 9 in sequence.

[0017] In this embodiment, a first hydraulic sensor 39 is provided on the electronically controlled hydraulic valve 3. When the system increases or decreases the hydraulic pressure of the brake circuit, the first hydraulic sensor 39 transmits the brake hydraulic pressure data back to the controller 8 in real time, and adjusts the system hydraulic pressure according to the real-time hydraulic pressure value, thereby performing closed-loop control of the system hydraulic pressure.

[0018] When parking: the first stop valve 70 is closed, the electromagnetic normally closed valve 71 and the electromagnetic normally open valve 73 are not energized, the electromagnetic normally closed valve 71 is closed, the electromagnetic normally open valve 73 is opened, the connection pipeline between the power source assembly 2 and the electronic parking cylinder 4 (i.e., the third high-pressure pipeline 67) is disconnected, and the parking rod 55 pulls the rear brake caliper 6 through the parking cable 64 under the spring force of the parking spring 60 to achieve parking; when releasing the parking: the first stop valve 70 is closed, the electromagnetic normally closed valve 71 is energized and opened, and the connection pipeline between the power source assembly 2 and the electronic parking cylinder 4 is opened The high-pressure brake fluid of the power source assembly 2 enters the high-pressure interface 65 of the electronic parking cylinder 4 through the secondary high-pressure port 15 and the third high-pressure pipeline 67, and then flows into the circular high-pressure chamber 58 through the electromagnetic normally closed valve 71 and the fourth small-diameter channel 69. At this time, the electromagnetic normally open valve 73 is energized and closed, and the second stop valve 74 is opened. Under the action of the hydraulic pressure, the high-pressure piston 59 moves axially and compresses the parking spring 60. The parking rod 55 also moves with the high-pressure piston 59. As the tension of the parking cable 64 on the rear brake caliper 6 gradually decreases until it reaches zero, the parking is released.

[0019] The electronic parking cylinder 4 is provided with a second hydraulic sensor 72. During the parking phase, the second hydraulic sensor 72 transmits the parking hydraulic data back to the controller 8 in real time. The hydraulic value should be zero when parking. The hydraulic value during the parking release phase should be consistent with the power source hydraulic value. The two sets of electromagnetic normally open valves 73 of the electronic parking cylinder 4 are alternately energized during the parking release phase to prevent the system from being continuously energized and overheating, resulting in failure. The parking system is provided with a solenoid valve failure mode. When the solenoid valve fails and the parking cannot be released, first manually rotate the second stop valve 74 until it is completely closed, and then manually rotate the first stop valve 70 to open it, so that the hydraulic energy of the power source assembly 2 flows into the circular high-pressure chamber 58 and the parking is released.

[0020] It should be noted that, in this document, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0021] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A wire-controlled hydraulic system for vehicle service and parking brakes, characterized in that: Includes hydraulic booster, power source assembly, electronically controlled hydraulic valve, electronic parking cylinder, front brake calipers and rear brake calipers; The electronically controlled hydraulic valve is used to hydraulically control the front and rear brake calipers, the electronic parking cylinder is used for parking brakes, the hydraulic booster includes an oil pot and a controller, the oil pot provides brake fluid for the power source assembly, the oil pot is provided with an oil pot return port and an oil pot oil outlet, the controller is used to control the operation of the power source assembly, the electronically controlled hydraulic valve and the electronic parking cylinder, the hydraulic booster is also provided with a master pump rear circuit interface, a high-pressure oil inlet and a high-pressure oil outlet; the power source assembly is provided with an oil inlet, a main high-pressure port and a secondary high-pressure port, the main high-pressure port is connected to the high-pressure oil inlet through a first high-pressure pipeline, and the oil inlet is connected to the oil pot outlet through an oil inlet pipeline; The electrically controlled hydraulic valve includes a control valve unit, a feedback unit and a motor unit; the control valve unit includes a control valve block, a feedback chamber and a sliding valve chamber are provided in the control valve block, a sliding valve is provided in the sliding valve chamber, the sliding valve includes a valve sleeve and a valve core, three first sealing rings are provided between the outer wall of the valve sleeve and the inner wall of the sliding valve chamber, a pressure relief valve port and a pressure relief valve port are also provided on the valve sleeve, the pressure relief valve port and the pressure relief valve port are both provided along the radial direction of the valve sleeve, the valve sleeve has a valve sleeve through hole, the valve core is located in the valve sleeve through hole, and the valve core and the valve sleeve are in sliding fit, a first small-diameter channel is provided in the valve core, an annular oil groove is provided on the middle outer wall of the valve core, the first small-diameter channel is connected between the feedback chamber and the annular oil groove, and when the valve core moves in the valve sleeve, the annular oil groove can be in contact with the feedback chamber. The pressure relief valve port or the pressure relief valve port is connected; one end of the valve core extends into the feedback chamber and is provided with a retaining ring at the end; a return spring is provided in the feedback chamber, and the two ends of the return spring respectively abut against the end of the feedback chamber and the retaining ring; the control valve block is also provided with a hydraulic sensing interface, a pressure relief interface, a working interface, a circuit master cylinder interface and a high-pressure oil inlet interface, the hydraulic sensing interface is connected with the feedback chamber, and a first hydraulic sensor is installed on the hydraulic sensing interface, and the control valve block is also provided with a second small-diameter channel, and the feedback chamber is sequentially connected to the working interface and the circuit master cylinder interface through the second small-diameter channel, and a shuttle valve is provided on the second small-diameter channel; the pressure relief interface is connected with the pressure relief valve port, and the high-pressure oil inlet interface is connected with the pressure relief valve port; The pressure relief interface is connected to the oil return port of the oil tank of the hydraulic booster through the first oil return line. The working interface is connected to the front brake caliper and the rear brake caliper through the front brake line and the rear brake line respectively. The circuit master cylinder interface is connected to the rear circuit interface of the master pump of the hydraulic booster through the rear line. The high-pressure oil inlet interface is connected to the high-pressure oil outlet of the hydraulic booster through the second high-pressure line. The feedback unit includes a feedback block, which is arranged at the end of the control valve block and uses a second sealing ring for end face sealing. A normal pressure chamber and a third small-diameter channel are provided in the feedback block. The third small-diameter channel is connected to the sliding valve chamber. A piston, a push rod and a feedback spring are provided in the normal pressure chamber. The piston can slide in the axial direction. Two third sealing rings are provided on the inner wall of the normal pressure chamber. The third sealing rings are used to seal the gap between the piston and the normal pressure chamber. A radial oil drain hole is provided on the feedback block. The radial oil drain hole is connected to the normal pressure chamber between the two sealing rings. The feedback spring is located between the push rod and the piston. One end of the push rod is located in the third small-diameter channel, and the end of the push rod abuts against the end of the valve core. The motor unit is arranged on the end surface of the feedback block, and the motor unit is used to push the piston to move forward and backward; The electronic parking cylinder includes a parking rod, a parking valve body and a housing, the parking valve body is installed at the end of the housing, a high-pressure chamber is provided in the parking valve body, the end of the high-pressure chamber is open, a high-pressure piston is provided in the high-pressure chamber, the high-pressure piston can slide in the high-pressure chamber, and the other end of the high-pressure piston extends into the housing, a parking spring and a spring seat are provided in the housing, a guide ring is provided on the outer periphery of the spring seat, the spring seat is slidably installed in the housing through the guide ring, the end of the high-pressure piston is connected to the spring seat, the parking spring is in contact with the inner wall of the housing and the spring seat, the parking rod is inserted through the end of the housing, the inner end of the parking rod is connected to the spring seat, the outer end of the parking rod is threadedly connected to a pull head, the parking hook coincides with the axis of the high-pressure piston, and the pull head is connected to the rear brake caliper through the parking cable; A high-pressure interface and an oil outlet nozzle are provided on the parking valve body. The high-pressure interface is connected to the secondary high-pressure port of the power source assembly through a third high-pressure pipeline, and the oil outlet nozzle is connected to the oil return port of the oil tank of the hydraulic booster through a second return oil pipeline; wherein a fourth small-diameter channel is provided in the parking valve body, and the high-pressure chamber is connected to the high-pressure interface and the oil outlet nozzle respectively through the fourth small-diameter channel, and a first stop valve, an electromagnetic normally closed valve, a second hydraulic sensor, two groups of electromagnetic normally open valves and a second stop valve are also installed on the parking valve body, wherein the first stop valve, the electromagnetic normally closed valve and the second hydraulic sensor are arranged on the connecting channel between the high-pressure chamber and the high-pressure interface, and the two groups of electromagnetic normally open valves and the second stop valve are arranged on the connecting channel between the high-pressure chamber and the oil outlet nozzle.

2. A wire-controlled hydraulic system for vehicle service and parking brakes according to claim 1, characterized in that: The motor unit is a linear servo motor, and the screw shaft of the linear servo motor is threadedly connected to the end of the piston.

3. The wire-controlled hydraulic system for vehicle service and parking brakes according to claim 1, characterized in that: A sliding sleeve is fixed in the normal pressure chamber, a key groove is provided on the inner wall of the sliding sleeve, and a sliding key is fixed on the outer wall of the piston. The sliding key can slide in the key groove of the sliding sleeve along the axial direction.

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