A hydraulic braking system

Abstract

The application discloses a hydraulic brake system, which comprises a hydraulic oil tank, a liquid supply pump, a pressure reducing valve group, a foot brake valve, a two-position four-way valve and an accumulator, the liquid inlet end of the liquid supply pump is connected with the hydraulic oil tank, the liquid outlet end of the liquid supply pump is connected with the pressure reducing valve group, the foot brake valve is connected with the pressure reducing valve group, the input end of the two-position four-way valve is connected with the pressure reducing valve group through an oil circuit, the output end of the two-position four-way valve is connected with a front axle and a rear axle, the accumulator is arranged at the input end of the two-position four-way valve, a first LS signal end is arranged on the two-position four-way valve, and the output LS signal is fed back to the liquid supply pump through the first LS signal end. Compared with the prior art, the hydraulic oil circuit control is adopted instead of the air top oil control mode, the brake reliability can be effectively improved, the brake pressure linear regulation is realized, and the brake performance is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of braking system, in particular to a hydraulic braking system. BACKGROUND

[0002] Engineering machinery is an important part of equipment industry. In general, engineering machinery is the mechanical equipment necessary for the comprehensive mechanized construction engineering required by earthwork construction engineering, pavement construction and maintenance, mobile hoisting and unloading operation and various building engineering. The working environment of large engineering machinery is generally harsh, for example, large excavators are generally used in construction sites and mining areas. Since there are many inclined road surfaces in the working environment, the terrain is complex, and therefore the braking system of the engineering machinery needs to have high reliability and sensitivity to ensure that the operator can better operate the engineering machinery and avoid engineering accidents.

[0003] The existing braking system generally adopts air top oil braking mode, as shown in Figure 3 The traditional braking system includes an air compressor 1', an air tank 2', a brake master cylinder 3', an operation brake solenoid valve 4', a two-way check valve 5', a fast release valve 6', a spring brake booster pump 71', a booster pump 72', a front drive axle 81' and a rear drive axle 82' connected in sequence. The traditional braking system needs to additionally increase air path elements such as the air compressor 1' and the air tank 2', and has a complex structure and high cost. Moreover, the traditional braking system uses air as the transmission medium. Since air contains water, it causes a safety hazard problem of brake failure due to water icing in cold northern areas, which limits the application range of the excavator. In addition, since the working environment of the excavator is harsh and dusty, impurities are easily introduced into the air path of the traditional braking system, which affects the braking performance of the whole machine and exists a safety hazard.

[0004] Therefore, the applicant has conducted in-depth research on the above problems, and thus the present application is produced. SUMMARY

[0005] The main purpose of the present application is to provide a hydraulic braking system which adopts hydraulic oil circuit control instead of air top oil control mode, can effectively improve the braking reliability, realize linear regulation of brake pressure, and further improve the braking performance.

[0006] In order to achieve the above purpose, the solution of the present application is:

[0007] The hydraulic brake system comprises a hydraulic oil tank, a liquid supply pump, a pressure reducing valve group, a foot brake valve, a two-position four-way valve and an accumulator, the liquid inlet end of the liquid supply pump is connected with the hydraulic oil tank, the liquid outlet end of the liquid supply pump is connected with the pressure reducing valve group, the foot brake valve is connected with the pressure reducing valve group, the input end of the two-position four-way valve is connected with the pressure reducing valve group through an oil circuit, the output end of the two-position four-way valve is connected with front and rear axles, the accumulator is arranged at the input end of the two-position four-way valve, and the first LS signal end is arranged on the two-position four-way valve, and the output LS signal is fed back to the liquid supply pump.

[0008] Further, the pressure reducing valve group comprises a first pressure reducing valve, a second pressure reducing valve, a safety overflow valve and a first electromagnetic valve, the first pressure reducing valve and the second pressure reducing valve are respectively connected with the liquid outlet end of the liquid supply pump, and the safety overflow valve and the first electromagnetic valve are connected with the output end of the second pressure reducing valve.

[0009] Further, the foot brake valve, the two-position four-way valve, the accumulator, the first pressure reducing valve, the second pressure reducing valve, the safety overflow valve, the first electromagnetic valve, the third pressure reducing valve, the work electromagnetic valve and the foot main pressure brake valve are arranged in the hydraulic brake system.

[0010] Compared with the prior art, the beneficial effects are that the hydraulic oil circuit control is adopted instead of the air top oil control mode, the brake system is prevented from being stuck and malfunctioning, the brake reliability is effectively improved, and the application range of the excavator is widened. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 It is a hydraulic principle diagram of the first embodiment of the present application.

[0012] Figure 2 It is a hydraulic principle diagram of the second embodiment of the present application.

[0013] Figure 3 It is a principle diagram of the brake system in the prior art.

[0014] In the drawings:

[0015] Hydraulic oil tank 1; fluid supply pump 2; pressure reducing valve assembly 3; first pressure reducing valve 31;

[0016] Second pressure reducing valve 32; safety relief valve 33; first solenoid valve 34; foot brake valve 4;

[0017] 5. Two-position four-way valve; 51. First LS signal terminal; 6. Accumulator; 7. Working solenoid valve.

[0018] Foot pedal main pressure brake valve 8; second LS signal terminal 81; third pressure reducing valve 9. Detailed Implementation

[0019] To further explain the technical solution of the present invention, the present invention will be described in detail below through specific embodiments.

[0020] like Figure 1 As shown, a hydraulic braking system includes a hydraulic oil tank 1, a hydraulic pump 2, a pressure reducing valve group 3, a foot brake valve 4, a two-position four-way valve 5, and an accumulator 6. The inlet end of the hydraulic pump 2 is connected to the hydraulic oil tank 1, and the outlet end of the hydraulic pump 2 is connected to the pressure reducing valve group 3. The foot brake valve 4 is connected to the pressure reducing valve group 3. The input end of the two-position four-way valve 5 is connected to the pressure reducing valve group 3 through an oil circuit. The output end of the two-position four-way valve 5 is connected to the front axle and the rear axle. The accumulator 6 is located at the input end of the two-position four-way valve 5. The two-position four-way valve 5 is provided with a first LS signal terminal 51. The first LS signal terminal 51 outputs an LS signal, which is filtered by a shuttle valve and other LS signals before being fed back to the hydraulic pump 2. In a first embodiment of the present invention, the pressure reducing valve assembly 3 includes a first pressure reducing valve 31, a second pressure reducing valve 32, a safety relief valve 33, and a first solenoid valve 34. The inlet end of the first pressure reducing valve 31 is connected to the outlet end of the supply pump 2, and the outlet end of the first pressure reducing valve 31 is connected to the input end of the two-position four-way valve 5. An accumulator 6 is connected between the outlet end of the first pressure reducing valve 31 and the input end of the two-position four-way valve 5. The inlet end of the second pressure reducing valve 32 is connected to the outlet end of the supply pump 2, and the outlet end of the second pressure reducing valve 32 is connected to the safety relief valve 33, the first solenoid valve 34, and the foot brake valve 4. The outlet end of the safety relief valve 33 is connected to the hydraulic oil tank 1. An accumulator 6 is also provided at the inlet end of the first solenoid valve 34, and the outlet end of the first solenoid valve 34 is connected to the two-position four-way valve 5.

[0021] With the above structure, the pressure reducing valve group 3 can provide the pressure oil required by the front and rear axle braking, and at the same time, the accumulator 6 can provide energy storage, keep the pressure stable, so that the braking is more rapid. When driving, the depth of the pedal brake valve 4 is controlled to operate the two-way four-way valve 5, the first LS signal end 51 on the two-way four-way valve 5 feeds back the LS signal to the liquid supply pump 2, so as to adjust the hydraulic supply of the liquid supply pump 2, realize linear adjustment of the braking pressure, adjust the brake effect, and improve the sensitivity of the brake braking. When parking, the electromagnetic valve directly controls the two-way four-way valve 5 to be fully opened, so that the braking pressure of the front and rear axle reaches the maximum value, ensuring that the four wheels are locked, and the operation is more convenient.

[0022] As shown in Figure 2 As a second embodiment of the present application, the braking system further comprises a work electromagnetic valve 7 and a pedal main pressure brake valve 8, the pressure reducing valve group 3 comprises a third pressure reducing valve 9, the liquid inlet end of the third pressure reducing valve 9 is connected with the liquid outlet end of the liquid supply pump 2, the liquid outlet end of the third pressure reducing valve 9 is connected with the work electromagnetic valve 7 and the pedal main pressure brake valve 8, the accumulator 6 is at the liquid outlet end of the third pressure reducing valve 9, the output end of the work electromagnetic valve 7 and the output end of the pedal main pressure brake valve 8 are respectively connected with the front axle and the rear axle, and the pedal main pressure brake valve 8 has the control function of the pedal brake valve 4 and the reversing function of the two-way four-way valve 5. The pedal main pressure brake valve 8 is provided with a second LS signal end 81, and the second LS signal end 81 feeds back the output LS signal to the liquid supply pump 2 through a shuttle valve and other LS signals.

[0023] With the above structure, the third pressure reducing valve 9 can provide the pressure oil required by the front and rear axle braking, and at the same time, the accumulator 6 can provide energy storage, keep the pressure stable, so that the braking is more rapid. When driving, the depth of the pedal main pressure brake valve 8 is controlled to make the second LS signal end 81 on the pedal main pressure brake valve 8 feed back its signal to the liquid supply pump 2 through a shuttle valve, control the pressure supply of the liquid supply pump 2, and realize linear adjustment of the braking pressure; when parking, the work brake electromagnetic valve directly controls the pressure oil to be connected to realize the maximum braking pressure of the front and rear axle, ensure that the four wheels are locked, and the operation is convenient.

[0024] The above embodiments and drawings are not limited to the product shape and style of the present application, and any appropriate changes or modifications made by those skilled in the art shall be considered as not departing from the scope of the present application.

Claims

1. A hydraulic brake system characterized by, The hydraulic oil tank, the liquid supply pump, the pressure reducing valve group, the foot brake valve, the two-position four-way valve and the accumulator are included, the liquid inlet end of the liquid supply pump is connected with the hydraulic oil tank, the liquid outlet end of the liquid supply pump is connected with the pressure reducing valve group, the foot brake valve is connected with the pressure reducing valve group, the input end of the two-position four-way valve is connected with the pressure reducing valve group through an oil path, the output end of the two-position four-way valve is connected with the front axle and the rear axle, the accumulator is arranged at the input end of the two-position four-way valve, a first LS signal end is arranged on the two-position four-way valve, the LS signal output by the first LS signal end is fed back to the liquid supply pump, the pressure reducing valve group includes a first pressure reducing valve, a second pressure reducing valve, a safety overflow valve and a first electromagnetic valve, the first pressure reducing valve and the second pressure reducing valve are respectively connected with the liquid outlet end of the liquid supply pump, the liquid outlet end of the first pressure reducing valve is connected with the input end of the two-position four-way valve, the liquid outlet end of the second pressure reducing valve is connected with the safety overflow valve, the first electromagnetic valve and the foot brake valve, and the safety overflow valve and the first electromagnetic valve are connected with the output end of the second pressure reducing valve.

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