Active pressure buildup unit with large-flow liquid guide one-way valve

Abstract

The utility model discloses an active pressure buildup unit with a large-flow liquid guide one-way valve, which is used in a brake-by-wire system and comprises two brake fluid loops, each brake fluid loop comprises an isolation branch and a fluid inlet branch, the isolation branch is provided with an isolation solenoid valve and a valve end one-way valve, the fluid inlet branch is provided with a fluid inlet solenoid valve and a plunger pump, and the valve end one-way valve is provided with a valve end one-way valve. And each brake fluid loop further comprises a fluid guide electromagnetic valve which is arranged in parallel with the isolation branch, and the fluid guide electromagnetic valve is used for reducing the closure resistance of the passage when the pedal brake pedal brakes. The large-flow liquid guide one-way valve is added to solve the problem that the closure resistance of a channel is large, and the large-flow liquid guide one-way valve is simple in structure, low in development cost and short in verification period and has obvious advantages.

Description

TECHNICAL FIELD

[0001] The utility model relates to a brake-by-wire system, especially a master pressure building unit with a large flow liquid guide check valve. BACKGROUND

[0002] With the continuous improvement of environmental perception technology, the driving assistance system can develop rapidly.

[0003] The driving assistance is finally realized through the control of the horizontal and longitudinal motion of the automobile, and the brake-by-wire system as a core safety component plays the most critical role.

[0004] The brake-by-wire system mainly consists of a liquid storage tank, a vehicle brake master cylinder actuated by a brake pedal, a master pressure building unit, an ABS anti-lock control system and a plurality of brake wheel cylinders. The master pressure building unit includes a pressure building motor, a cam, a plunger pump, an isolation electromagnetic valve and a valve end check valve, and a liquid inlet electromagnetic valve.

[0005] When the pressure building motor of the master pressure building unit is not working, the driver steps on the brake pedal to provide braking, and the brake fluid flows through the isolation electromagnetic valve, the valve end check valve and the ABS anti-lock control system to realize the braking of each brake wheel cylinder.

[0006] In the implementation of the utility model, the inventor finds that: because the isolation electromagnetic valve and the valve end check valve have small hole diameters, there is obvious flow resistance, which makes the driver feel obvious pedal resistance.

[0007] In order to reduce the pedal resistance, it is necessary to improve the existing brake-by-wire system. CONTENT OF THE UTILITY MODEL

[0008] The utility model aims at providing a master pressure building unit with a large flow liquid guide check valve to reduce the brake pedal resistance.

[0009] Therefore, the utility model provides a master pressure building unit for use in a brake-by-wire system, which includes two brake fluid circuits, each of which includes an isolation branch and a liquid inlet branch. The isolation branch is provided with an isolation electromagnetic valve and a valve end check valve, and the liquid inlet branch is provided with a liquid inlet electromagnetic valve and a plunger pump. Each brake fluid circuit further includes a liquid guide check valve arranged in parallel in the isolation branch, which is used to reduce the flow resistance of the passage when the driver steps on the brake pedal.

[0010] Further, the plunger pump of each brake fluid circuit is driven by the same power source.

[0011] Further, the power source includes a pressure building motor and a cam, wherein the pressure building motor rotates the cam to drive the plunger pump.

[0012] Further, the isolation electromagnetic valve is a two-position two-way electromagnetic valve, and the liquid inlet electromagnetic valve is a two-position two-way electromagnetic valve.

[0013] Further, the brake-by-wire system comprises a liquid storage tank, a vehicle brake master cylinder, an ABS anti-lock control system and a plurality of brake wheel cylinders, wherein the vehicle brake master cylinder provides two paths of brake fluid to the active pressure building unit, and the active pressure building unit provides two paths of brake fluid to the ABS anti-lock control system.

[0014] Further, the nominal pass of the liquid guide check valve is greater than or equal to 4mm.

[0015] The large-flow liquid guide check valve has the advantages of simple structure, low development cost, short verification period and obvious advantages.

[0016] In addition to the purposes, features and advantages described above, the utility model has other purposes, features and advantages. BRIEF DESCRIPTION OF DRAWINGS

[0017] The drawings accompanying the specification of this application form a part hereof, serve to provide further understanding of the utility model, and together with the description of the utility model's illustrative embodiments and its description serve the purpose of explaining the utility model, and do not constitute an inappropriate limitation of the utility model. In the drawings:

[0018] Figure 1 is a structural schematic view of the active pressure building unit with the large-flow liquid guide check valve of the utility model. DETAILED DESCRIPTION

[0019] The utility model will be described in detail below with reference to the drawings and in combination with embodiments.

[0020] As Figure 1 shown, the brake-by-wire system of the utility model comprises a liquid storage tank, a vehicle brake master cylinder, an active pressure building unit, an ABS anti-lock control system and a plurality of brake wheel cylinders.

[0021] The active pressure building unit comprises two paths of brake fluid circuits, each brake fluid circuit comprises an isolation branch and a liquid inlet branch, wherein the isolation branch is provided with a two-position two-way isolation electromagnetic valve and a valve end check valve, and the liquid inlet branch is provided with a two-position two-way liquid inlet electromagnetic valve and a plunger pump.

[0022] The vehicle brake master cylinder provides two brake fluid paths to the active pressure building unit, in which each brake fluid path supplies the ABS anti-lock control system through an isolation branch or an inlet branch.

[0023] In the original design, when the motor is not working, the driver steps on the brake pedal to provide braking, and the brake fluid flows to the ABS braking system through the isolation solenoid valve and the valve end check valve to achieve braking. Since the isolation solenoid valve and the valve end check valve have small apertures, there is obvious flow resistance, and the driver can feel obvious pedal resistance.

[0024] In the utility model, the active pressure building unit increases a large-flow liquid guide check valve, which is in parallel connection with the isolation solenoid valve. The driver steps on the brake pedal to provide braking, and the brake fluid flows to the ABS braking system through the isolation solenoid valve, the valve end check valve and the large-flow liquid guide check valve to achieve braking. The utility model can significantly reduce the flow resistance of the path by increasing the large-flow liquid guide check valve, thereby reducing the brake pedal resistance.

[0025] The large-flow liquid guide check valve is relative to the flow capacity of the isolation branch, and the flow capacity CV value is 5-30 times that of the isolation branch. In an embodiment, a large-flow liquid guide check valve with a nominal flow diameter of 4 mm is selected.

[0026] When the active brake works, the inlet solenoid valve is opened, the isolation solenoid valve is closed, the motor rotates the cam to drive the plunger pump to suck brake fluid from the inlet solenoid valve, and then pump out the brake fluid. The valve end check valve reversely stops, the large-flow liquid guide check valve reversely stops, the brake fluid flows to the ABS anti-lock control system to achieve braking. The large-flow liquid guide check valve added in the utility model has no influence on the active braking function.

[0027] In order to reduce the problem of obvious flow resistance of the isolation solenoid valve and the valve end check valve due to small apertures, the traditional scheme is to increase the apertures of the isolation solenoid valve and the valve end check valve. However, since the solenoid valve has compact structure and high integration, there are disadvantages such as high design verification cost and long research and development period. The problem is solved by increasing the large-flow liquid guide check valve, which has simple structure, low development cost and short verification period, and has obvious advantages.

[0028] The above description is only an embodiment of the utility model, and is not used to limit the utility model. For those skilled in the art, the utility model can have various changes and changes. Any modification, replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims

1. An active pressure building unit for use in a brake-by-wire system, comprising two brake fluid circuits, each brake fluid circuit comprising an isolated branch and a fluid inlet branch, wherein the isolated branch is provided with an isolated solenoid valve and a valve end check valve, and the fluid inlet branch is provided with a fluid inlet solenoid valve and a plunger pump, characterized in that, Each brake fluid circuit further comprises a guide liquid one-way valve arranged in parallel with the isolation branch, for reducing the resistance of the passage when the foot brake pedal is braked.

2. The positive pressure building unit of claim 1, wherein, The plunger pump of each brake fluid circuit is driven by the same power source.

3. The positive pressure building unit of claim 2, wherein, The power source comprises a pressure building unit and a cam, wherein the pressure building unit drives the plunger pump by rotating the cam.

4. The positive pressure building unit of claim 1, wherein, The isolation electromagnetic valve is a two-position two-way electromagnetic valve, and the inlet liquid electromagnetic valve is a two-position two-way electromagnetic valve.

5. The positive pressure building unit of claim 1, wherein, The brake-by-wire system comprises a liquid storage tank, a vehicle brake master cylinder, an ABS anti-lock control system, and a plurality of brake wheel cylinders, wherein the vehicle brake master cylinder provides two paths of brake fluid to the active pressure building unit, and the active pressure building unit provides two paths of brake fluid to the ABS anti-lock control system.

6. The positive pressure building unit of claim 1, wherein, The guide liquid one-way valve has a nominal passage diameter of 4 mm or more.

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