Integrated electronic hydraulic power assisting system

Abstract

An integrated electronic hydraulic power assisting system comprises a brake unit, a power unit, a booster assembly and a wheel side load. The brake unit comprises a brake master cylinder, and a master cylinder oil can and a displacement sensor which are connected with the brake master cylinder; the booster assembly comprises a pedal piston, a first master cylinder piston, a second master cylinder piston, a first throttle valve, a second throttle valve and a third throttle valve, and the brake master cylinder is connected with a cavity of the first master cylinder piston, a cavity of the second master cylinder piston and a pedal oil inlet end of the pedal piston through the first throttle valve, the second throttle valve and the third throttle valve respectively; the boosting oil outlet end of the pedal piston is connected with the first master pump piston and the second master pump piston, the oil outlet end of the first master pump piston and the oil outlet end of the second master pump piston are connected with the wheel side load, and the high-pressure oil inlet end and the oil return end of the pedal piston are connected with the power unit. According to the system, the leakage risk of the high-pressure brake fluid can be reduced, the manual brake function and the brake-by-wire function can be achieved, the synchronism of brake force is better, and time delay or lag feeling is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic power assistance, in particular to an integrated electronic hydraulic power assistance system. Background Art

[0002] In the prior art, the HCU valve block and the booster housing are of a split structure, and the two are connected by an O-ring and bolts to achieve high-pressure and low-pressure seals. However, there is a risk of high-pressure brake fluid leakage in the high-pressure seal. During the braking process, the high-pressure brake fluid pushes the master cylinder piston to move, and squeezes the brake fluid in the piston closed cavity to achieve the braking effect. However, when there are two or more pistons, the multiple pistons are usually connected in series by springs, and the front and rear pistons are pushed forward in sequence to push all the pistons forward. The pressure in the front and rear piston closed cavities will form a braking delay due to the delay of the acting force, resulting in insufficient precision of braking control and affecting the driving experience of users.

[0003] The redundant design of the braking system is an important barrier to protect the safety of drivers. In the existing electronic hydraulic power assistance system, the high-pressure energy storage system may fail due to power failure or other faults, and there is no high-pressure brake fluid to drive the master cylinder piston to move, which will affect the driving braking function of the vehicle.

[0004] Therefore, it is necessary to design an integrated electronic hydraulic power assistance system to overcome the above problems. Summary of the Utility Model

[0005] In order to avoid the above problems, an integrated electronic hydraulic power assistance system is provided. The solenoid valve and the pressure sensor are installed on the booster housing, reducing the HCU valve block and also reducing the risk of high-pressure brake fluid leakage; it can realize manual and wire control braking functions, and the synchronism of braking force is better, without delay or lag feeling.

[0006] An integrated electronic hydraulic power assistance system provided by the utility model includes: a braking unit, a power unit, a booster assembly, and a wheel side load;

[0007] The braking unit includes a brake master cylinder, a master cylinder oil pot connected to the brake master cylinder, and a displacement sensor. The displacement sensor is connected to the brake pedal; the booster assembly includes a foot piston, a first master cylinder piston, a second master cylinder piston, a first throttle valve, a second throttle valve, and a third throttle valve. The brake master cylinder is connected to the cavity of the first master cylinder piston through the first throttle valve, the brake master cylinder is connected to the cavity of the second master cylinder piston through the second throttle valve, the brake master cylinder is connected to the foot inlet end of the foot piston through the third throttle valve, the booster outlet end of the foot piston is respectively connected to the first master cylinder piston and the second master cylinder piston, the outlet ends of the first master cylinder piston and the second master cylinder piston are respectively connected to the wheel side load, and the high-pressure inlet end and the return end of the foot piston are connected to the power unit.

[0008] Preferably, a first master cylinder chamber and a second master cylinder chamber are arranged in series on the master cylinder.

[0009] Preferably, the booster assembly includes a stroke simulator, and the second master cylinder chamber is connected to the power oil pot of the power unit through the stroke simulator.

[0010] Preferably, the high-pressure oil inlet end of the foot piston is connected to the oil outlet end of the power unit, the oil return end of the foot piston is connected to the power oil pot of the power unit, and the by-wire oil inlet end of the foot piston is connected to the oil outlet end of the accumulator through the PSV valve and connected to the power oil pot through the USV valve.

[0011] Preferably, the booster assembly includes four pressure sensors, all of which are arranged on the booster housing, namely the PACC accumulator pressure sensor, the PMC foot piston chamber pressure sensor, the PWC wheel side load pressure sensor, and the PB by-wire oil inlet piston chamber pressure sensor.

[0012] Preferably, the booster assembly includes a buffer, which is connected to the by-wire oil inlet end of the foot piston.

[0013] Preferably, a CSV valve is provided between the third throttle valve and the foot oil inlet end of the foot piston.

[0014] Compared with the prior art, the present utility model has the following beneficial effects:

[0015] 1. The overall system structure can achieve manual and by-wire braking functions;

[0016] 2. The vehicle layout is more convenient, and the parts of the booster assembly can be arranged at any position of the vehicle;

[0017] 3. Two or more master cylinder pistons are arranged in parallel, and the synchronism of the braking force is better, without delay or lag feeling;

[0018] 4. The solenoid valve and the pressure sensor are press-fitted on the booster housing, saving the development cost of the HCU valve block;

[0019] 5. A throttle valve is provided on the pipeline for shunting, so that when braking manually, the oil can flow into the foot oil inlet chamber through the throttle valve, improving the pressure building speed of manual braking;

[0020] 6. When there is no energy storage, the oil directly flows from the master cylinder through the master cylinder piston to the wheel side for braking. Its structure is novel. The master cylinder piston is the active part during manual braking and by-wire braking, performing braking; when the accumulator fails, the master cylinder piston is a hydraulic conduction chamber, and the sealing leather cup divides the piston chamber, and the oil can only flow to the wheel side. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of an integrated electro-hydraulic booster system according to a preferred embodiment of the present utility model;

[0022] Description of the attached drawing reference numerals:

[0023] 1. Brake unit, 11. Master brake cylinder, 111. First chamber of the master cylinder, 112. Second chamber of the master cylinder, 12. Master cylinder oil pot, 13. Displacement sensor

[0024] 2. Brake pedal

[0025] 3. Booster assembly, 31. Pedal piston, 311. Pedal oil inlet end, 312. Booster oil outlet end, 313. High-pressure oil inlet end, 314. Oil return end, 315. By-wire oil inlet end, 32. First master piston, 33. Second master piston, 34. First throttle valve, 35. Second throttle valve, 36. Third throttle valve, 37. Stroke simulator, 38. Buffer

[0026] 4. Power unit, 41. Accumulator, 42. Power oil pot

[0027] 5. Wheel-end load Detailed implementation manners

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0029] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0030] As Figure 1 shown, an integrated electro-hydraulic power steering system provided in this embodiment includes: a brake unit 1, a power unit 4, a booster assembly 3, and a wheel-end load 5.

[0031] Specifically, the brake unit 1 includes a master cylinder 11, a master cylinder oil pot 12 connected to the master cylinder 11, and a displacement sensor 13. The displacement sensor 13 is connected to the brake pedal 2. Among them, the booster assembly 3 includes a foot piston 31, a first master piston 32, a second master piston 33, a first throttle valve 34, a second throttle valve 35, and a third throttle valve 36. The master cylinder 11 is connected to the chamber of the first master piston 32 through the first throttle valve 34, the master cylinder 11 is connected to the chamber of the second master piston 33 through the second throttle valve 35, and the master cylinder 11 is connected to the foot inlet end 311 of the foot piston 31 through the third throttle valve 36. The booster outlet end 312 of the foot piston 31 is respectively connected to the first master piston 32 and the second master piston 33. The outlet ends of the first master piston 32 and the second master piston 33 are respectively connected to the wheel-side load 5. The high-pressure inlet end 313 and the oil return end 314 of the foot piston 31 are respectively connected to the power unit 4.

[0032] Among them, the first master piston 32 and the second master piston 33 are arranged in parallel. The driving oil can enter the first master piston 32 and the second master piston 33 simultaneously, ensuring the consistency and simultaneity of the output pressures of the first master piston 32 and the second master piston 33 (without delay and lag feeling), and maintaining the sensitivity of braking.

[0033] At the same time, the high-pressure inlet end 313 of the foot piston 31 is connected to the oil outlet end of the accumulator 41 of the power unit 4, the oil return end 314 of the foot piston 31 is connected to the power oil pot 42 of the power unit 4, the by-wire inlet end 315 of the foot piston 31 is connected to the accumulator 41 through the PSV valve and connected to the power oil pot 42 through the USV valve, and a CSV valve is provided between the third throttle valve 36 and the foot inlet end 311 of the foot piston 31. The booster assembly 3 includes a buffer 38, which is connected to the by-wire inlet end 315 of the foot piston 31. During the by-wire braking process, it slows down the high-pressure impact of the instantaneous release of high-pressure oil on the by-wire inlet piston, and improves the pressure control error during the by-wire braking process. The by-wire braking pressure is accurately regulated through the USV valve and the buffer 38. When reducing the pressure in the by-wire piston chamber and releasing the braking pressure inside the foot piston 31, the USV valve can be opened to release the high-pressure oil to the power oil pot.

[0034] Moreover, a master cylinder first chamber 111 and a master cylinder second chamber 112 are arranged in series on the master cylinder 11, and the booster assembly 3 includes a stroke simulator 37. The master cylinder second chamber 112 is connected to the power oil pot 42 of the power unit 4 through the stroke simulator 37. When compressing the spring of the stroke simulator 37, the sealed oil in the spring chamber can be pressed back to the power oil pot 42. In this system, the stroke simulator 37 mainly absorbs the stroke of the second chamber 112 of the master cylinder 11 (the stroke of the second chamber is longer than that of the first chamber), increases the stroke of the brake pedal 2, and realizes the complete decoupling of the brake pedal 2.

[0035] During actual operation, the design and layout of the three throttle valves, namely the first throttle valve 34, the second throttle valve 35, and the third throttle valve 36, are considered such that when manually braking, most of the brake fluid needs to enter the foot piston 31 through the third throttle valve 36. After the foot piston 31 moves to push the valve core and release the high-pressure brake fluid, the high-pressure brake fluid enters the tail ends of the first master cylinder piston 32 and the second master cylinder piston 33, thereby driving the pistons to move forward and generating the braking function. When the high-pressure accumulator 41 fails and there is no high-pressure energy storage, the brake fluid first enters the foot piston 31 through the third throttle valve 36 and pushes the foot piston 31 to move to the maximum position. Although the valve core can be pushed, there is no release of high-pressure oil fluid from the valve core, and thus the first master cylinder piston 32 and the second master cylinder piston 33 cannot be pushed to move further, forming a self-locking structure and unable to brake. At this time, the oil fluid in the foot piston 31 cavity is saturated and cannot consume the brake fluid any more, but the brake pedal 2 can continue to move forward, and the brake fluid can also be distributed into the first master cylinder piston 32 cavity and the second master cylinder piston 33 cavity through the first throttle valve 34 and the second throttle valve 35, and the brake fluid slides past the sector leather cup and directly flows to the wheel side load 5. Since the entire first master cylinder chamber 111 and the second master cylinder chamber 112 form a sealed piston chamber, the braking force of the brake pedal 2 is directly converted into hydraulic pressure and leads to the wheel side load 5, generating the braking function, which can meet the emergency braking (braking redundancy) without assistance and improve the safety of driving braking.

[0036] Among them, the three solenoid valves, namely the PSV valve, the USV valve, and the CSV valve, and one displacement sensor 13 are mainly used for the wire-controlled braking of the integrated electronic hydraulic power assist system. After receiving the braking signal of the brake pedal 2, the displacement sensor 13 transmits the signal to the ECU, and the ECU controls the actions of the three solenoid valves to generate the braking effect. The main control ECU is mainly used to receive the braking and brake release signals of the brake pedal 2 identified by the displacement sensor 13, as well as the braking and brake release signals sent by the vehicle system to the ECU, and monitor the pipeline pressure during the braking process, and give the optimal autonomous braking plan to improve the safety of the vehicle's active braking during driving. At the same time, the main control ECU is mainly used to monitor the working pressure of the accumulator 41. When the pressure is lower than the minimum working pressure, the ECU control system powers on the motor of the power unit 4 to make the plunger pump of the power unit 4 work. When the accumulator 41 reaches the maximum working pressure, the ECU control system powers off the motor of the power unit 4, and so on, to keep the power unit 4 in a normal working state.

[0037] The booster assembly 3 includes four pressure sensors, all of which are arranged on the booster housing, namely the PACC accumulator 41 pressure sensor, the PMC foot piston 31 cavity pressure sensor, the PWC wheel side load 5 pressure sensor, and the PB wire-controlled oil inlet piston cavity pressure sensor. During the wire-controlled braking process, the pressure of each chamber is monitored in real time to meet the requirement of accurately controlling the braking pressure.

[0038] Working principle:

[0039] Manual Pilot Braking: Step on the brake pedal 2, the first chamber 111 and the second chamber 112 of the master cylinder start to compress, and the pressure in the two closed chambers begins to rise. Part of the brake fluid in the first chamber 111 and the second chamber 112 of the master cylinder directly flows into the wheel end through the first master cylinder piston 32 chamber and the second master cylinder piston 33 chamber, generating an initial braking pressure; at the same time, the brake fluid in the second chamber 112 of the master cylinder enters the stroke simulator 37, compressing the spring of the stroke simulator 37 to increase the pedal stroke, and the brake fluid in the first chamber 111 of the master cylinder enters the foot pedal inlet piston chamber at the same time. When the pressure of the brake master cylinder 11 reaches a certain value, the foot pedal piston 31 (manual piston) will move forward and push open the low-pressure valve seat. The high-pressure brake fluid quickly passes through the boost oil outlet end 312 and is released to the tails of the first master cylinder piston 32 and the second master cylinder piston 33, pushing the pistons of the first master cylinder piston 32 and the second master cylinder piston 33 forward, and then passing over the sector leather cup to form two closed chambers. Driven by the high-pressure oil, the pressure in the closed chambers of the first master cylinder piston 32 and the second master cylinder piston 33 is released to the wheel end load 5 through the oil outlet to generate braking. After releasing the brake pedal 2, the pistons of the first master cylinder piston 32 and the second master cylinder piston 33 reset, and the oil returns to the master cylinder oil pot 12 and the power oil pot 42 through the oil return pipeline respectively.

[0040] By-Wire Pilot Braking: Step on the brake pedal 2, the displacement sensor 13 of the brake master cylinder 11 identifies the displacement signal and transmits it to the control module ECU. After the ECU identifies the braking request signal, it opens the PSV valve (normally closed valve) and closes the CSV valve (normally open valve) at the same time. The high-pressure brake fluid enters the foot pedal piston 31 chamber through the by-wire oil inlet end 315. When the pressure in the foot pedal piston 31 chamber reaches a certain value, the piston in the foot pedal piston 31 chamber will move forward and push open the low-pressure valve seat. The high-pressure brake fluid quickly passes through the boost oil outlet end 312 and is released to the tails of the first master cylinder piston 32 and the second master cylinder piston 33, pushing the pistons of the first master cylinder piston 32 and the second master cylinder piston 33 forward, and then passing over the sector leather cup to form two closed chambers. Driven by the high-pressure oil, the pressure in the closed chambers of the first master cylinder piston 32 and the second master cylinder piston 33 is released to the wheel end load 5 through the oil outlet to generate braking. After releasing the brake pedal 2, the piston resets, and the oil returns to the master cylinder oil pot 12 and the power oil pot 42 through the oil return pipeline respectively. During this process, according to the braking demand, the wheel end pressure required for the braking deceleration can be accurately matched. The pressure at the by-wire oil inlet piston end is mainly released through the USV (normally open valve) to achieve accurate control of the wheel end pressure.

[0041] Non-Power-Assisted Braking: When the accumulator 41 fails, by stepping on the brake hard, the brake fluid in the first chamber 111 and the second chamber 112 of the master cylinder directly flows into the wheel end through the first master cylinder piston 32 and the second master cylinder piston 33. The brake pressure can be generated for the wheel end load 5 by compressing the oil in the two closed pipelines, so as to achieve emergency braking and ensure the reliability of the vehicle braking system.

[0042] The overall structure of the system can achieve manual and wire-controlled braking functions, making vehicle layout more convenient. The components of the booster assembly 3 can be arranged at any position of the vehicle; the braking force synchronization is better, without delay or lag feeling; the solenoid valve and pressure sensor are press-fitted on the booster housing, saving the development cost of the HCU valve block; a throttle valve is provided on the pipeline for flow splitting. When braking manually, the oil can flow into the foot pedal inlet chamber through the third throttle valve 36, improving the pressure build-up speed of manual braking; when there is no energy storage, the oil directly flows from the brake master cylinder 11 through the first master cylinder piston 32 and the second master cylinder piston 33 to the wheel ends for braking. Its structure is novel. The master cylinder pistons are active components during manual and wire-controlled braking, performing braking; when the accumulator 41 fails, the first master cylinder piston 32 and the second master cylinder piston 33 serve as hydraulic conduction chambers, and the sealing leather cup divides the piston chamber, and the oil can only flow to the wheel ends.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated electronic hydraulic power steering system, characterized in that, Comprising: A braking unit, a power unit, a booster assembly, and a wheel-end load; The braking unit includes a brake master cylinder, a master cylinder oil pot connected to the brake master cylinder, and a displacement sensor, and the displacement sensor is connected to the brake pedal; the booster assembly includes a foot piston, a first master cylinder piston, a second master cylinder piston, a first throttle valve, a second throttle valve, and a third throttle valve. The brake master cylinder is connected to the cavity of the first master cylinder piston through the first throttle valve, the brake master cylinder is connected to the cavity of the second master cylinder piston through the second throttle valve, the brake master cylinder is connected to the foot inlet end of the foot piston through the third throttle valve, the boost outlet end of the foot piston is respectively connected to the first master cylinder piston and the second master cylinder piston, the outlet ends of the first master cylinder piston and the second master cylinder piston are respectively connected to the wheel-end load, and the high-pressure inlet end and the oil return end of the foot piston are connected to the power unit.

2. The integrated electronic hydraulic power steering system according to claim 1, characterized in that: A master cylinder chamber one and a master cylinder chamber two are arranged in series on the brake master cylinder.

3. The integrated electro-hydraulic power steering system according to claim 2, characterized in that: The booster assembly includes a stroke simulator, and the master cylinder chamber two is connected to the power oil pot of the power unit through the stroke simulator.

4. The integrated electronic hydraulic power steering system according to claim 1, wherein: The high-pressure inlet end of the foot piston is connected to the oil outlet end of the power unit, the oil return end of the foot piston is connected to the power oil pot of the power unit, and the by-wire inlet end of the foot piston is connected to the oil outlet end of the accumulator through a PSV valve and to the power oil pot through a USV valve.

5. The integrated electronic hydraulic power steering system according to claim 4, wherein: The booster assembly includes four pressure sensors, all of which are arranged on the booster housing, namely a PACC accumulator pressure sensor, a PMC foot piston chamber pressure sensor, a PWC wheel-end load pressure sensor, and a PB by-wire inlet piston chamber pressure sensor.

6. The integrated electronic hydraulic power steering system according to claim 1, wherein: The booster assembly includes a buffer, which is connected to the by-wire inlet end of the foot piston.

7. The integrated electronic hydraulic power steering system as described in claim 1, characterized in that: A CSV valve is provided between the third throttle valve and the foot inlet end of the foot piston.

Images