WO2016045211A1

WO2016045211A1 - Hydraulic braking unit

Info

Publication number: WO2016045211A1
Application number: PCT/CN2014/094453
Authority: WO
Inventors: 张致兴; 吴志强; 潘劲; 刘伟
Original assignee: 浙江万向精工有限公司; 万向集团公司
Priority date: 2014-09-28
Filing date: 2014-12-19
Publication date: 2016-03-31
Also published as: CN104309595A; CN104309595B

Abstract

A hydraulic braking unit, which is additionally provided with a high-pressure energy accumulator, ensures timely braking and can effectively control pressure reduction. The hydraulic braking unit comprises a first braking passage (1), a second braking passage (2), a third braking passage (3), a fourth braking passage (4), a first pressure-relieving passage (10), a second pressure-relieving passage (20), a third pressure-relieving passage (30) and a fourth pressure-relieving passage (40). The hydraulic braking unit is structurally characterized by being further provided with a high-pressure energy accumulator (22). Due to the fact that the hydraulic braking unit is additionally provided with the high-pressure energy accumulator (22), and the four braking passages are mutually independent, when one braking mode fails, braking can be independently realized in another mode, so that timely braking is guaranteed, the braking efficiency and reliability are improved, the reasonability of the whole braking process is improved, and the frequency of valve operation is reduced.

Description

Hydraulic brake unit

Technical field

The invention relates to the field of hydraulic braking, in particular to a hydraulic brake unit which increases a high-pressure accumulator, ensures timely braking and can effectively control decompression.

Background technique

The brake of the existing hydraulic brake unit is mainly amplified by the pedaling force of the brake pedal, and the oil in the brake master cylinder is hydraulically fed into the brake by the forward movement of the piston, thereby increasing the hydraulic pressure and making the wheel Action. Such as China Patent Licensing Bulletin No. CN 202508080, the announcement date of October 31, 2012, the patent name vehicle brake system, wherein the hydraulic control unit includes a brake fluid tank, a plunger pump brake master cylinder, a brake and various regulating valves, etc., in this patent, all The brakes are connected to the brake master cylinder.

However, such a setting may have a pressure increase that is not timely, and the build time is longer, resulting in a brake that is not timely and affects the braking effect.

On the other hand, the normally closed switching valve in the existing hydraulic brake unit cannot effectively control the decompression speed, thereby causing high pressure, pressure keeping and decompression frequency, which is not conducive to control, and also increases equipment loss.

Summary of the invention

The technical problem to be solved by the present invention is to provide a hydraulic brake unit with reasonable structural design, increased high-pressure accumulator, timely braking and effective control of decompression.

The technical solution adopted by the present invention to solve the above technical problems is as follows:

A hydraulic brake unit includes a first brake passage, a second brake passage, a third brake passage, a fourth brake passage and a first pressure relief passage, a second pressure relief passage, and a third pressure relief passage, The fourth pressure relief passage also includes a high pressure accumulator.

a first brake and a first pressure increasing valve are sequentially disposed on the first brake passage, and the first pressure increasing valve is respectively connected to the first normally open switching valve and the first brake valve, and the first brake valve is connected to the high pressure accumulator a second brake and a second pressure increasing valve are sequentially disposed on the second brake passage, and the second pressure increasing valve is respectively connected to the first normally open switching valve and the first brake valve, and the first brake valve is connected to the high pressure storage a third brake and a third pressure increasing valve are sequentially disposed on the third brake passage, and the third pressure increasing valve is respectively connected to the second normally open switching valve and the second brake valve, and the second brake valve is connected to the high pressure storage The fourth brake passage is sequentially provided with a fourth brake and a fourth booster valve, and the fourth booster valve is respectively connected to the second normally open reversing valve and the second brake valve, and the second brake valve is connected to the high pressure An accumulator; a plunger pump is connected between the high-pressure accumulator and the second brake valve and the first brake valve, and the plunger pump is further connected with a drive motor.

a first brake, a first pressure limiting valve and a first pressure reducing valve are arranged in sequence on the first pressure relief passage, and a second brake, a second pressure limiting valve and a first pressure reducing valve are sequentially arranged on the second pressure relief passage. The third pressure relief passage is provided with a third brake, a third pressure limiting valve and a second pressure reducing valve in sequence, and a fourth brake, a fourth pressure limiting valve and a second pressure reducing valve are sequentially disposed on the fourth pressure relief passage. The first pressure relief passage and the second pressure relief passage are connected to the brake fluid tank through the first pressure reducing valve, and the third pressure relief passage and the fourth pressure relief passage are connected to the brake fluid tank through the second pressure reducing valve.

The first brake, the second brake, the third brake, and the fourth brake are respectively provided with wheel speed sensors. A sensor is provided on the high pressure accumulator.

a pressure sensor is disposed between the first brake and the first pressure limiting valve, a pressure sensor is disposed between the second brake and the second pressure limiting valve, and a pressure sensor is disposed between the third brake and the third pressure limiting valve. A pressure sensor is provided between the four brakes and the fourth pressure limiting valve. A check valve is also provided on the brake passage connected to the high pressure accumulator.

The first normally open reversing valve and the second normally open reversing valve are respectively connected with the brake master cylinder, the brake master cylinder is connected with the brake fluid tank, and the plunger pump is also connected with the brake fluid tank; the first pressure relief passage, The second pressure relief passage is connected to the brake fluid tank through the first pressure reducing valve, and the third pressure relief passage and the fourth pressure relief passage are connected to the brake fluid tank through the second pressure reducing valve.

The brake master cylinder is provided with a first working chamber and a second working chamber, the third brake passage and the fourth brake passage are connected to the first working chamber, and the first brake passage and the second brake passage are connected to the second working chamber. Or the first brake passage and the second brake passage are connected to the first working chamber, and the third brake passage and the fourth brake passage are connected to the second working chamber. A piston and a return spring are respectively disposed in the first working chamber and the second working chamber of the brake master cylinder. A brake pedal is also connected to the brake master cylinder, and a displacement sensor is provided on the brake pedal.

Preferably, the brake master cylinder is provided with two working chambers, and the two brake passages are respectively connected to the two working chambers of the brake master cylinder, and the advantage is that the two brake passages share one working chamber, which improves Boost speed, reduce build time and improve braking efficiency.

Preferably, a pressure sensor is disposed between the first brake and the first pressure limiting valve, pressure sensing is provided between the second brake and the second pressure limiting valve, and pressure is provided between the third brake and the third pressure limiting valve. The sensor, the fourth brake and the fourth pressure limiting valve are provided with a pressure sensor, and the utility model has the advantages that the pressure sensor can reflect the hydraulic condition of each wheel position in real time, and is convenient for controlling the decompression speed and improving the braking efficiency.

Preferably, the plunger pump employs a six-plunger configuration which has the advantage of increasing plunger efficiency.

Preferably, the one-way valve is provided on the brake passage connected to the high-pressure accumulator, which has the advantage of preventing backflow when the oil pressure at the wheel position is large.

Compared with the prior art, the invention has the following advantages and effects:

1. Since a high-pressure accumulator is added to the hydraulic brake unit, the accumulator has a rated pressure. If the pressure is lower than the rated value, the pressure is increased by the plunger pump, and the brake pressure is lower than the rated pressure. Pressure to achieve the effect of keeping the brakes in time.

2. Since the four brake passages have two oil supply modes, namely two braking modes, when the high-pressure accumulator brake fails, the pressure in the brake can be established directly through the normally open reversing valve, and the system completes the routine. Braking, which in turn increases the reliability of the brakes.

3. Since the pressure in the wheel cylinder is controlled by the pressure limiting valve, it is easy to reduce the pressure in the wheel cylinder, reducing the pressure pulsation and noise.

4. Since the algorithm for estimating the required pressure according to the deceleration is adopted, the pressure increasing valve and the pressure limiting valve are controlled, thereby improving the braking accuracy.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

Figure 1 is a schematic view of the structure of the present invention.

Label description:

1: first brake passage; 2: second brake passage; 3: third brake passage; 4: fourth brake passage; 5: brake pedal; 6: electronic control unit; 10: first pressure relief Path; 20: second pressure relief passage; 30: third pressure relief passage; 40: fourth pressure relief passage; 11: brake fluid tank; 12: brake master cylinder; 121: first working chamber; 122: Two working chambers; 123: return spring; 124: piston; 13: first normally open reversing valve; 14: first booster valve; 15: first brake; 151: wheel speed sensor; 16: first pressure limiting valve ; 161: pressure sensor; 17: first pressure reducing valve; 21: plunger pump; 211: drive motor; 22: high pressure accumulator; 221: sensor; 23: first brake valve; 24: check valve; 25: second booster valve; 26: second brake; 27: second pressure limiting valve; 31: second normally open reversing valve; 32: third booster valve; 33: third brake; 34: third Pressure limiting valve; 35: second pressure reducing valve; 41: second brake valve; 43: fourth pressure increasing valve; 44: fourth brake; 45: fourth pressure limiting valve.

detailed description

The invention will be further described in detail below with reference to the embodiments, which are to be construed as the invention.

As shown in FIG. 1, a hydraulic brake unit of the present invention includes a first brake passage 1, a second brake passage 2, a third brake passage 3, a fourth brake passage 4, and a first pressure relief passage 10. The second pressure relief passage 20, the third pressure relief passage 30, and the fourth pressure relief passage 40.

The first brake passage 1 is in turn a first brake 15 and a first pressure increasing valve 14, and the first pressure increasing valve 14 is connected to the first normally open switching valve 13 and the first brake valve 23, respectively. 23 connects the high pressure accumulator 22.

The second brake passage 2 is sequentially provided with a second brake 26 and a second pressure increasing valve 25, and the second pressure increasing valve 25 is connected to the first normally open switching valve 13 and the first brake valve 23, respectively. The valve 23 is connected to the high pressure accumulator 22.

The third brake passage 3 is sequentially provided with a third brake 33 and a third pressure increasing valve 32. The third pressure increasing valve 32 is connected to the second normally open switching valve 31 and the second brake valve 41, respectively. The valve 41 is connected to the high pressure accumulator 22.

A fourth brake 44 and a fourth pressure increasing valve 43 are sequentially disposed on the fourth brake passage 4, and the fourth pressure increasing valve 43 is connected to the second normally open switching valve 31 and the second brake valve 41, respectively. The valve 41 is connected to the high pressure accumulator 22.

A plunger pump 21 is connected between the high-pressure accumulator 22 and the second brake valve 41 and the first brake valve 23, and the plunger pump is further connected with a drive motor 211 for driving the plunger pump 21 so that the plunger pump The oil in the brake fluid tank 11 is transferred to the high pressure accumulator 22. A check valve 24 is further disposed on the passage connected to the high-pressure accumulator 22, and as shown in FIG. 1, the check valve 24 functions to prevent a backflow phenomenon when the oil pressure at the wheel position is large, thereby affecting the braking effect. Of course, the check valve 24 may not be provided.

The inlet end of the first normally open reversing valve 13 is connected to the second working chamber 122 of the brake master cylinder 12, and the inlet end of the second normally open reversing valve 31 is connected to the first working chamber 121 of the brake master cylinder 12, and the brake is applied. The liquid tank 11 is connected to the first working chamber 121 and the second working chamber 122 of the master cylinder 12, respectively. Of course, it is also possible that the first normally open switching valve 13 is connected to the first working chamber 121, the second normally open switching valve 31 is connected to the second working chamber 122, and even the brake master cylinder 12 can have only one working chamber, the first Both the open reversing valve 13 and the second normally open reversing valve 31 are connected to this single working chamber.

The brake master cylinder 12 is divided into a first working chamber 121 and a second working chamber 122. The first working chamber 121 and the second working chamber 122 are respectively provided with a piston 124 and a return spring 123. The piston 124 is connected to the brake pedal 5 via a push rod. A displacement sensor 51 is provided on the brake pedal 5. When the brake pedal 5 is depressed, the oil reaches the brake from the master cylinder 12 as the piston 124 advances, thereby braking the wheel.

In order to increase the efficiency of the plunger, the plunger pump 21 in this embodiment employs a six-plunger structure.

The first brake passage 1, the second brake passage 2, the third brake passage 3, and the fourth brake passage 4 each have two kinds of oil supply paths, that is, through the high pressure accumulator 22 or the brake master cylinder 12 The brakes provide hydraulic pressure. In the present embodiment, the high-pressure accumulator 22 functions as an oil reservoir. The high-pressure accumulator 22 is connected to the sensor 221, and the high-pressure accumulator 22 should maintain the rated pressure inside. Usually, the plunger passes through the plunger when the pressure is lower than the rated value. The pump 21 replenishes the pressure, and in the braking phase, when the pressure is lower than the rated pressure, the replenishing pressure is also required in time to ensure the timeliness of the braking.

Therefore, even if the high-pressure accumulator 22 fails, the pressure in the brake can be established directly through the normally open reversing valve to complete the conventional braking; if the conventional braking fails, the braking passage connecting the high-pressure accumulator 22 can also be independently The vehicle is braked to ensure the reliability of the brake.

The first brake 15, the second brake 26, the third brake 33, and the fourth brake 44 are also respectively connected with a wheel speed sensor 151, and the wheel speed sensor 151 can detect the real-time running condition of the wheel, such as acceleration, deceleration, etc., and the wheel The real-time operating conditions are reacted to the electronic control unit 6, which then analyzes the operating conditions and makes corresponding adjustments as needed.

The first pressure relief passage 10 is sequentially provided with a first brake 15, a first pressure limiting valve 16, and a first pressure reducing valve 17; the second pressure relief passage 20 is provided with a second brake 26 and a second pressure limiting valve 27 in this order. a first pressure reducing valve 17; a third brake 33, a third pressure limiting valve 34, and a second pressure reducing valve 35 are sequentially disposed on the third pressure relief passage 30; and a fourth brake is sequentially disposed on the fourth pressure relief passage 40. 44. The fourth pressure limiting valve 45 and the second pressure reducing valve 35.

Between the first brake 15 and the first pressure limiting valve 16, between the second brake 26 and the second pressure limiting valve 27, between the third brake 33 and the third pressure limiting valve 34, the fourth brake 44 and the fourth limit A pressure sensor 161 is respectively disposed between the pressure valves 45, and the pressure sensor 161 can detect the real-time pressure condition of the wheel position and feed back to the electronic control unit 6, and the electronic control unit 6 performs the pressure increasing valve and the pressure limiting valve according to the operating conditions. Effective control makes the whole brake control process more reasonable and the valve action frequency is reduced.

In addition, in the present invention, the pressure limiting valve is used to control the pressure in the wheel cylinder, and it is easy to reduce the pressure in the wheel cylinder, thereby reducing pressure pulsation and noise.

The braking principle of the present invention is as follows:

When braking, the normally open reversing valve, the brake valve, and the pressure limiting valve are energized, the pressure in the high pressure accumulator 22 enters the brake, and the wheel speed decreases until the electronic control unit 6 recognizes that the wheel is locked by the wheel speed sensor 151. The tendency is up. When braking, when the pressure in the high pressure accumulator 22 is lower than the rated pressure, the plunger pump 21 operates and maintains the pressure in the high pressure accumulator 22 not lower than the rated pressure.

When the electronic control unit 6 recognizes that a certain wheel has a tendency to lock by the signal obtained by the wheel speed sensor 151, the electronic control unit 6 closes the wheel pressure increasing valve, and the pressure limiting valve is still closed.

If the wheel still has a tendency to lock during the pressure holding phase, the ABS system enters the depressurization phase. At this time, the electronic control unit 6 estimates the required pressure of the brake according to the braking deceleration, and determines and controls the frequency limiting duty ratio of the pressure limiting valve according to the pressure difference, so that the pressure limiting valve maintains a critical state (the pressure is higher than the wheel cylinder pressure) When the pressure limiting valve is lower than the pressure of the wheel cylinder, the pressure limiting valve remains closed. If the sensing pressure is lowered, the pressure reducing valve is opened to discharge the brake fluid to the brake fluid tank). If the wheel is still in a locked state, the duty ratio of the pressure limiting valve is appropriately lowered, and the electromagnetic force is reduced, and the balance between the differential pressure force before and after the pressure limiting valve, the hydraulic power, the electromagnetic force, and the spring restoring force is broken. The pressure limiting valve limits the pressure drop, and finally the wheel cylinder pressure is reduced. At this time, the pressure reducing process is a linear pressure reduction, which reduces the reciprocating cycle caused by the rapid pressurization of the wheel cylinder. If you need to increase the wheel cylinder pressure, increase the duty cycle of the pressure limiting valve. In the subsequent control process, the booster valve also controls the linear pressurization of the wheel cylinder through the high frequency adjustment duty cycle, thereby ensuring proper pressure in the wheel cylinder.

During the running of the vehicle, when the system detects that the pressure in the high pressure accumulator 22 is lower than the rated pressure, the plunger pump 21 is automatically activated to ensure that the pressure in the high pressure accumulator 22 is not lower than the rated pressure.

Further, it should be noted that the specific embodiments described in the present specification may have zeros, shape of components, names taken, and the like. Equivalent or simple changes made to the structures, features and principles of the present invention are included in the scope of the invention. A person skilled in the art can make various modifications or additions to the specific embodiments described or in a similar manner, without departing from the scope of the invention or the scope defined by the claims. All should fall within the scope of protection of the present invention.

Claims

A hydraulic brake unit includes a first brake passage, a second brake passage, a third brake passage, a fourth brake passage and a first pressure relief passage, a second pressure relief passage, and a third pressure relief passage, a fourth pressure relief passage, characterized in that: a high pressure accumulator is further included,

a first brake and a first pressure increasing valve are sequentially disposed on the first brake passage, and the first pressure increasing valve is respectively connected to the first normally open switching valve and the first brake valve, wherein the first a brake valve is connected to the high pressure accumulator;

a second brake and a second pressure increasing valve are sequentially disposed on the second brake passage, and the second pressure increasing valve is respectively connected to the first normally open switching valve and the first brake valve, a first brake valve connected to the high pressure accumulator;

a third brake and a third pressure increasing valve are sequentially disposed on the third brake passage, and the third pressure increasing valve is respectively connected to the second normally open switching valve and the second brake valve, and the second a brake valve is connected to the high pressure accumulator;

a fourth brake and a fourth pressure increasing valve are sequentially disposed on the fourth brake passage, and the fourth boosting valve is respectively connected to the second normally open switching valve and the second brake valve, a second brake valve is coupled to the high pressure accumulator;

a plunger pump is connected between the high pressure accumulator and the second brake valve and the first brake valve, and the plunger pump is further connected with a driving motor;

The first pressure relief passage is provided with a first brake, a first pressure limiting valve and a first pressure reducing valve, and the second pressure limiting passage is provided with a second brake and a second pressure limiting valve in sequence. a first pressure reducing valve, wherein the third pressure relief passage is provided with a third brake, a third pressure limiting valve and a second pressure reducing valve, and the fourth pressure relief passage is provided with a fourth brake, The fourth pressure limiting valve and the second pressure reducing valve.
The hydraulic brake unit according to claim 1, wherein said first normally open directional control valve and said second normally open directional control valve are respectively connected to a brake master cylinder, said brake master cylinder connection system a hydraulic fluid tank, wherein the plunger pump is further connected to the brake fluid tank; the first pressure relief passage and the second pressure relief passage are connected to the brake fluid tank through a first pressure reducing valve, The third pressure relief passage and the fourth pressure relief passage are connected to the brake fluid tank through a second pressure reducing valve.
The hydraulic brake unit according to claim 1, wherein said first brake, said second brake, said third brake, and said fourth brake are respectively provided with wheel speed sensors.
The hydraulic brake unit according to claim 1 or 3, wherein a pressure sensor is disposed between the first brake and the first pressure limiting valve, and a second brake and the second pressure limiting valve are disposed between the second brake and the second pressure limiting valve. The pressure sensor has a pressure sensor disposed between the third brake and the third pressure limiting valve, and a pressure sensor is disposed between the fourth brake and the fourth pressure limiting valve.
The hydraulic brake unit of claim 1 wherein said high pressure accumulator is coupled to a sensor.
A hydraulic brake unit according to claim 1, wherein a check valve is further provided on the brake passage connected to said high pressure accumulator.
A hydraulic brake unit according to claim 2, wherein said brake master cylinder is provided with a first working chamber and a second working chamber, and said third brake passage and said fourth brake passage are connected. a first working chamber, the first brake passage and the second brake passage are connected to the second working chamber, or the first brake passage and the second brake passage are connected to the first working chamber, the first The three brake passages and the fourth brake passage are connected to the second working chamber.
The hydraulic brake unit according to claim 7, wherein a piston and a return spring are respectively disposed in the first working chamber and the second working chamber of the brake master cylinder.
The hydraulic brake unit according to claim 7 or 8, wherein said brake master cylinder is further connected with a brake pedal, and said brake pedal is provided with a displacement sensor.
The hydraulic brake unit of claim 1 wherein said plunger pump is a six-plunger configuration.