ESC hydraulic braking structure with noise reduction unit

Abstract

The utility model discloses an ESC hydraulic brake structure with a noise reduction unit, which comprises a brake master cylinder, the output end of the brake master cylinder is connected with a plurality of brake master cylinder loops, one brake master cylinder loop comprises a supply structure and a brake structure, the output end of the brake master cylinder is connected with the supply structure, and the output end of the brake master cylinder is connected with the brake structure. The supply structure is connected with the brake structure through a supply line and an oil return line, and a noise reduction valve is additionally arranged in the supply structure. The noise reduction valve comprises a valve seat, a valve bag, a valve element and a return spring assembly, the ESC hydraulic brake structure with the noise reduction unit adopts the structure, and solves the problems of brake pedal shaking and abnormal noise caused by pressure pulsation excitation of a vehicle type with a non-decoupling type electromechanical servo mechanism adopted as a brake booster in the prior art; under the situation that background noise in a pure electric automobile is low, the NVH problem caused by hydraulic pulsation is more remarkable, and the abnormal shaking and noise can severely reduce the braking comfort of the automobile.

Description

Technical Field

[0001] The utility model relates to the technical field of ESC hydraulic brake structures, in particular to an ESC hydraulic brake structure with a noise reduction unit. Background Art

[0002] New energy vehicles refer to vehicles that use new power systems and are completely or mainly driven by new energy. At present, power battery vehicles are the mainstream of new energy vehicles. Compared with traditional fuel vehicles, electric vehicles are more likely to obtain high horsepower. At this time, the braking system is particularly important. In order to improve the braking performance of the vehicle, the equipment of ESC (electronic stability control system) is very necessary. ESC is a comprehensive braking system. The ESC system consists of sensors, ECU (electronic control unit) and actuators. The sensors mainly include 4 wheel speed sensors, steering wheel angle sensor, lateral acceleration sensor, yaw rate sensor, brake master cylinder pressure sensor, etc.; ECU monitors the running status of the vehicle and intervenes in the vehicle engine and braking system; the hydraulic actuator HCU contains units such as motors and valve blocks.

[0003] Conventional HCU hydraulic control unit consists of solenoid valve, accumulator assembly, plunger pump, motor, pressure sensor, etc. HCU hydraulic control unit is an important part of the ESC system to realize active pressure building, pressure boosting, pressure maintenance, pressure reduction and conventional braking. The ESC assembly uses hydraulic pressure as the braking energy source. When the HCU pressure builds, the motor drives the plunger pump to generate hydraulic pressure. Due to the hydraulic characteristics of the plunger pump, there is pressure pulsation, which causes hydraulic abnormal noise and NVH problems. The motor of new energy vehicles is quieter than that of traditional new energy vehicles, so the NVH problem has become an issue that must be taken seriously. Utility Model Content

[0004] The purpose of the utility model is to provide an ESC hydraulic brake structure with a noise reduction unit to solve the problem that the brake pedal jitter and abnormal noise caused by pressure pulsation excitation are caused by the current vehicle models with non-decoupled electromechanical servo mechanisms for the brake booster. In the context of low background noise in the pure electric vehicle, the NVH problem caused by hydraulic pulsation is more significant, and this abnormal jitter and noise will seriously reduce the braking comfort of the vehicle.

[0005] To achieve the above-mentioned purpose, the utility model provides an ESC hydraulic brake structure with a noise reduction unit, including a brake master cylinder, wherein the output end of the brake master cylinder is connected to a plurality of brake master cylinder circuits, a brake master cylinder circuit includes a supply structure and a brake structure, the output end of the brake master cylinder is connected to the supply structure, the supply structure is connected to the brake structure via a supply line and an oil return line, and a noise reduction valve is additionally added to the supply structure.

[0006] Preferably, the output end of the brake master cylinder is connected to the input end of the oil supply valve, the output end of the oil supply valve is connected to the input end of the plunger pump, the output end of the plunger pump is connected to the input end of the noise reduction valve, and the output end of the noise reduction valve is connected to the supply line.

[0007] Preferably, the supply line is connected to the input end of the pressure regulating valve, a pressure sensor is provided between the brake master cylinder and the pressure regulating valve, and the output end of the pressure regulating valve is connected to the input end of the brake structure.

[0008] Preferably, the braking structure includes two circuits of the same structure, namely a first braking circuit and a second braking circuit, the first braking circuit includes a first boosting valve, the output end of the first boosting valve is connected to the first brake wheel cylinder and the input end of the first pressure reducing valve in sequence, the second braking circuit includes a second boosting valve, the output end of the second boosting valve is connected to the second brake wheel cylinder and the input end of the second pressure reducing valve in sequence, and the output end of the first pressure reducing valve and the output end of the second pressure reducing valve in the second braking circuit are both connected to the return oil line.

[0009] Preferably, the oil return line includes a low-pressure accumulator, and the oil return line is connected to the input end of the plunger pump through a one-way valve.

[0010] Preferably, a plurality of filters are provided in the circuits of the supply structure and the brake structure.

[0011] Preferably, the noise reduction valve comprises a valve seat, a valve core and a valve bag which are arranged in sequence, a return spring is arranged in the valve bag, and after the brake fluid flows in, it flows through the valve seat and the valve core and enters the valve bag.

[0012] Therefore, the utility model adopts an ESC hydraulic brake structure with a noise reduction unit of the above structure, optimizes the ESC hydraulic unit structure, and adds a noise reduction valve assembly in series with the plunger pump in each of the two brake circuits. When the ESC achieves active pressurization, the pressure pulsation in the hydraulic circuit can be effectively suppressed, thereby reducing the uncomfortable feeling brought to the driver by the jitter and noise of the brake pedal.

[0013] The technical solution of the utility model is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a structural schematic diagram of an ESC hydraulic brake structure with a noise reduction unit according to the utility model;

[0015] Figure 2 This is a schematic diagram of the noise reduction valve structure of an ESC hydraulic brake structure with a noise reduction unit of the utility model;

[0016] Figure 3 This is a schematic diagram of an ESC hydraulic brake structure with a noise reduction unit according to the utility model;

[0017] Figure 4 It is the active pressure building curve of the ESC hydraulic brake structure when there is no noise reduction valve assembly;

[0018] Figure 5 This is an active pressure building curve of an ESC hydraulic brake structure with a noise reduction unit in the utility model;

[0019] 1. Brake master cylinder circuit; 2. Motor; 3. Pressure regulating valve; 4. Oil supply valve; 5. Noise reduction valve; 51. Valve seat; 52. Valve bag; 6. Plunger pump; 7. Low-pressure accumulator; 8. Pressure sensor; 9. First boosting valve; 10. Second boosting valve; 11. First pressure reducing valve; 12. Second pressure reducing valve. DETAILED DESCRIPTION

[0020] The technical solution of the utility model is further described below through the accompanying drawings and embodiments.

[0021] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the usual meanings understood by persons with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] Example

[0023] like Figure 1 An ESC hydraulic brake structure with a noise reduction unit shown in the figure includes a brake master cylinder, and the output end of the brake master cylinder is connected to a plurality of brake master cylinder circuits 1, one brake master cylinder circuit 1 includes a supply structure and a braking structure, the output end of the brake master cylinder is connected to the supply structure, the supply structure is connected to the braking structure via a supply line and an oil return line, and a noise reduction valve 5 is additionally added to the supply structure.

[0024] The output end of the brake master cylinder is connected to the input end of the oil supply valve 4, the output end of the oil supply valve 4 is connected to the input end of the plunger pump 6, the output end of the plunger pump 6 is connected to the input end of the noise reduction valve 5, and the output end line of the noise reduction valve 5 is connected to the supply line. The supply line is connected to the input end of the pressure regulating valve 3. A pressure sensor 8 is provided between the brake master cylinder and the pressure regulating valve 3. The pressure sensor 8 is used to detect the pressure of the oil inlet and is only provided on one of the brake master cylinder circuits 1. The output end of the pressure regulating valve 3 is connected to the input end of the brake structure.

[0025] The braking structure includes two circuits with the same structure, namely a first braking circuit and a second braking circuit. The first braking circuit includes a first boosting valve 9, and the output end of the first boosting valve 9 is connected to the first brake wheel cylinder and the input end of the first pressure reducing valve 11 in sequence. The second braking circuit includes a second boosting valve 10, and the output end of the second boosting valve 10 is connected to the second brake wheel cylinder and the input end of the second pressure reducing valve 12 in sequence. The output end of the first pressure reducing valve 11 and the output end of the second pressure reducing valve 12 in the second braking circuit are both connected to the return oil line.

[0026] The oil return line includes a low-pressure accumulator 7, which has the functions of recovering energy, buffering and stabilizing pressure, and providing a low-pressure environment for the outlet of the oil return line. The oil return line is connected to the input end of the plunger pump 6 through a one-way valve.

[0027] Filters are connected in the circuits of the supply structure and the brake structure. The filters are respectively arranged on both sides of the pressure regulating valve 3, both sides of the oil supply valve 4, and both sides of the first boosting valve 9 and the second boosting valve 10.

[0028] like Figure 2 The noise reduction valve 5 shown in the figure includes a valve seat 51, a valve bag 52, a valve core, a return spring and other components. When the pressure-building unit motor 2 builds up pressure, the pressure pulsation flows through the valve seat 51, and the valve core enters the valve bag 52, which plays a role in buffering and noise reduction. In the absence of pressure or pressure difference, due to the action of the return spring, the valve core fits the valve seat 51 and plays a sealing role. After the noise reduction valve 5 component is installed in the ESC system, when the ESC system realizes active boosting, the brake fluid flows from the master cylinder through the oil supply valve 4, then to the plunger pump 6, and then flows through the noise reduction valve 5, and finally flows into the brake wheel cylinder through the first boost valve 9 to realize the boosting function.

[0029] Figure 3 In the embodiment shown, two brake master cylinder circuits are included; the supply structure of each brake master cylinder circuit includes a pressure regulating valve and an oil supply valve, and the pressure regulating valve is connected to the brake structure for regulating the pressure. The pressure regulating valve is connected to the noise reduction valve, and the brake fluid flows from the plunger pump through the noise reduction valve to the pressure regulating valve and cannot flow in the reverse direction. The noise reduction valve is connected to the plunger pump, and the oil supply valve is connected to the plunger pump to provide brake fluid to the plunger pump. At the same time, a motor is connected to the two plunger pumps to provide power for the plunger pumps.

[0030] The brake structure of each brake master cylinder circuit includes two wheels, each wheel corresponds to a booster valve and a pressure reducing valve, and the output ends of the two pressure reducing valves in a brake master cylinder circuit are commonly connected to the oil return line, which is sequentially connected to the low-pressure accumulator, plunger pump, and noise reduction valve. The two brake master cylinder circuits include a total of four wheels.

[0031] When the ESC boost function is turned on, the system enters the active boost state. During this process, the driver does not step on the brake pedal, and there is no pressure in the brake master cylinder. The plunger pump builds up pressure in the wheel cylinder to achieve active braking. In this stage, the four wheels are actively boosted, the boost valve remains in the open state without power, and the pressure regulating valve is powered on and closed. The oil supply valve is powered on and opened, and the motor is powered on to drive the plunger pump to work. The brake fluid is transferred from the brake master cylinder---oil supply valve---plunger pump---noise reduction valve---boost valve---wheel cylinder to achieve pressure growth on the four wheels.

[0032] like Figure 4 , Figure 5 As shown in the figure, the pressure build-up curve of the ESC system with a noise reduction valve is significantly smoother and the amplitude is reduced compared to the conventional ESC system under the same working conditions. Therefore, the application of the noise reduction valve suppresses the pressure pulsation in the hydraulic circuit and reduces the uncomfortable feeling brought to the driver by the vibration and noise of the brake pedal.

[0033] The utility model adopts an ESC hydraulic brake structure with a noise reduction unit of the above structure, which solves the problem that the brake pedal jitter and abnormal noise caused by pressure pulsation excitation are caused in the current vehicle models with non-decoupled electromechanical servo mechanisms for the brake booster. In the context of low background noise inside the pure electric vehicle, the NVH problem caused by hydraulic pulsation is more significant, and this abnormal jitter and noise will seriously reduce the braking comfort of the vehicle.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that they can still modify or replace the technical solution of the utility model with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the utility model.

Claims

1. An ESC hydraulic brake structure with a noise reduction unit, characterized in that: It includes a brake master cylinder, the output end of which is connected to several brake master cylinder circuits, one brake master cylinder circuit includes a supply structure and a braking structure, the output end of the brake master cylinder is connected to the supply structure, the supply structure is connected to the braking structure through a supply line and an oil return line, and a noise reduction valve is additionally added to the supply structure.

2. The ESC hydraulic brake structure with a noise reduction unit according to claim 1, characterized in that: The output end of the brake master cylinder is connected to the input end of the oil supply valve, the output end of the oil supply valve is connected to the input end of the plunger pump, the output end of the plunger pump is connected to the input end of the noise reduction valve, and the output end of the noise reduction valve is connected to the supply line.

3. The ESC hydraulic brake structure with a noise reduction unit according to claim 2, characterized in that: The supply line is connected to the input end of the pressure regulating valve, a pressure sensor is arranged between the brake master cylinder and the pressure regulating valve, and the output end of the pressure regulating valve is connected to the input end of the brake structure.

4. The ESC hydraulic brake structure with a noise reduction unit according to claim 3, characterized in that: The braking structure includes two circuits with the same structure, namely a first braking circuit and a second braking circuit. The first braking circuit includes a first boosting valve, and the output end of the first boosting valve is connected to the first brake wheel cylinder and the input end of the first pressure reducing valve in sequence. The second braking circuit includes a second boosting valve, and the output end of the second boosting valve is connected to the second brake wheel cylinder and the input end of the second pressure reducing valve in sequence. The output end of the first pressure reducing valve and the output end of the second pressure reducing valve in the second braking circuit are both connected to the return oil line.

5. The ESC hydraulic brake structure with a noise reduction unit according to claim 4, characterized in that: The oil return line includes a low-pressure accumulator, and the oil return line is connected to the input end of the plunger pump through a one-way valve.

6. The ESC hydraulic brake structure with a noise reduction unit according to claim 5, characterized in that: A plurality of filters are arranged in the circuits of the supply structure and the brake structure.

7. The ESC hydraulic brake structure with a noise reduction unit according to claim 6, characterized in that: The noise reduction valve comprises a valve seat, a valve core and a valve bag which are arranged in sequence. A return spring is arranged in the valve bag. After the brake fluid flows in, it flows through the valve seat and the valve core and enters the valve bag.

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