CN-116788353-B - Liquid filling valve, hydraulic steering braking system and engineering vehicle

Abstract

The invention discloses a liquid filling valve, a hydraulic steering braking system and an engineering vehicle, wherein the liquid filling valve comprises a priority valve and a pilot unloading valve, an opening LS1 of the priority valve is connected with an opening P of the pilot unloading valve, a second one-way valve and a pressure maintaining device are sequentially arranged on a passage from an opening CF of the priority valve to an opening A of the liquid filling valve, the pressure maintaining device adopts a valve piece for controlling one-way flow of oil, a pilot oil passage is led out between the second one-way valve and the pressure maintaining device and is connected to a pilot oil port of the pilot unloading valve, the hydraulic steering braking system comprises an energy accumulator, a steering gear and the liquid filling valve, the opening A of the liquid filling valve is connected with the energy accumulator, the opening CF of the priority valve is connected with an opening P of the steering gear, the opening LS of the pilot unloading valve is connected with an opening LS of the steering gear, and the engineering vehicle adopts the hydraulic steering braking system. The liquid filling valve provided by the invention has the advantages of simple structure, low cost and good pressure maintaining capability, and the hydraulic steering braking system provided by the invention has the advantages of simple structure, high system integration level and small system pressure loss.

Inventors

• YE HAIXIANG
• ZHANG FUYI
• LIU MAOSEN
• HE YADONG

Assignees

• 徐州重型机械有限公司

Dates

Publication Date

20260505

Application Date

20230628

Claims (10)

1. 1. The hydraulic steering braking system is characterized by comprising a braking system, a steering system and a charging valve, wherein the charging valve comprises a priority valve (6) and a pilot unloading valve (7), an LS1 port of the priority valve (6) is connected with a P port of the pilot unloading valve (7), a second one-way valve (8) and a pressure maintaining device are sequentially arranged on a passage from a CF port of the priority valve (6) to an A port of the charging valve, the pressure maintaining device adopts a valve piece for controlling one-way flow of oil, a pilot oil passage is led out between the second one-way valve (8) and the pressure maintaining device and is connected to a pilot oil port of the pilot unloading valve (7), the braking system comprises a braking pedal valve (11), a braking oil cylinder (12) and an accumulator (3), the steering system comprises a steering gear (13), an A port of the charging valve is connected with the accumulator (3), the CF port of the priority valve (6) is connected with the P port of the steering gear (13), the LS port of the pilot unloading valve (7) is connected with the LS port of the steering gear (13), and high-pressure oil in the accumulator (3) is supplied to the braking oil cylinder (12) through the braking pedal valve (11).
2. 2. Hydraulic steering brake system according to claim 1, characterized in that the pressure maintaining means employs a third non return valve (9).
3. 3. The hydraulic steering brake system according to claim 2, wherein the charge valve is a double-circuit charge valve having two ports a, the two ports a being A1 and A2, respectively, and the pressure maintaining device is two third check valves (9) arranged in parallel, the two third check valves (9) being connected to the ports A1 and A2, respectively.
4. 4. Hydraulic steering brake system according to claim 1, characterized in that the pressure maintaining means employs a second sequence valve (10).
5. 5. A hydraulic steering brake system according to claim 4, characterized in that a charging valve C opening is led between the second non-return valve (8) and the second sequence valve (10) for providing a sufficient safety driving pressure in case of a sudden drop in the failure pressure at the a opening.
6. 6. The hydraulic steering brake system according to claim 4, wherein the charge valve is a double-circuit charge valve having two ports a, the two ports a being A1 and A2, respectively, and the pressure maintaining device is two second sequence valves (10) arranged in parallel, and respective oil outlets of the two second sequence valves (10) are connected to the ports A1 and A2, respectively.
7. 7. The hydraulic steering braking system is characterized by comprising a braking system, a steering system and a charging valve, wherein the charging valve comprises a priority valve (6) and a pilot unloading valve (7), an LS1 port of the priority valve (6) is connected with a P port of the pilot unloading valve (7), a second one-way valve (8) and a pressure maintaining device are sequentially arranged on a passage from a CF port of the priority valve (6) to an A port of the charging valve, and the pressure maintaining device adopts a valve piece for controlling one-way flow of oil liquid; The pressure maintaining device adopts a third one-way valve (9) or a second sequence valve (10), when the pressure maintaining device adopts the third one-way valve (9), the liquid filling valve is a double-loop liquid filling valve with two ports A, the two ports A are respectively A1 port and A2 port, the pressure maintaining device adopts two third one-way valves (9) which are arranged in parallel, the two third one-way valves (9) are respectively connected with the A1 port and the A2 port, when the pressure maintaining device adopts the second sequence valve (10), the liquid filling valve is a double-loop liquid filling valve with two ports A, the two ports A are respectively the A1 port and the A2 port, the pressure maintaining device adopts two second sequence valves (10) which are arranged in parallel, and respective oil outlets of the two second sequence valves (10) are respectively connected with the A1 port and the A2 port; The braking system comprises a brake pedal valve (11), a brake oil cylinder (12) and two energy accumulators (3), the steering system comprises a steering gear (13), a charging valve A1 port and a charging valve A2 port are respectively connected with the two energy accumulators (3), a priority valve (6) CF port is connected with a steering gear (13) P port, a pilot unloading valve (7) LS port is connected with the steering gear (13) LS port, and high-pressure oil in the two energy accumulators (3) is supplied to the brake oil cylinder (12) through the brake pedal valve (11).
8. 8. A hydraulic steering brake system according to claim 7, characterized in that a charging valve C opening is led between the second non-return valve (8) and the second sequence valve (10) for providing a sufficient safety driving pressure in case of a sudden drop in the failure pressure at the a opening.
9. 9. A working vehicle, characterized in that the working vehicle applies the hydraulic steering brake system according to claim 1 or 7.
10. 10. The work vehicle of claim 9, wherein the work vehicle comprises a crane, a container crane, a forklift, and a loader.

Description

Liquid filling valve, hydraulic steering braking system and engineering vehicle Technical Field The invention belongs to the technical field of vehicle running control, and relates to a liquid filling valve, a hydraulic steering braking system and an engineering vehicle. Background The charging valve is a hydraulic valve for storing high-pressure oil provided by the main pump in the accumulator, and the high-pressure oil stored in the accumulator can be used for realizing functions of driving, parking and the like. Fig. 1 shows a schematic diagram of a conventional charge valve, when oil enters the charge valve from a port P, a spring in a first one-way valve 1 has a certain opening pressure, the opening pressure is greater than the spring set pressure of a two-way three-way pilot operated directional valve 5, the two-way three-way pilot operated directional valve 5 is switched to a left valve position, the oil flows to a port a, the port a is connected with an accumulator 3, after the circuit builds up pressure, the two-way three-way pilot operated directional valve 4 is pushed to be in a right valve position, the pressure of the port a continuously rises, when the pressure is higher than the set pressure of a first sequence valve 2, the first sequence valve 2 is opened, the accumulator 3 stores the pressure, the pressure is greater than the set pressure of the first one-way valve 1, the two-way three-way pilot operated directional valve 5 is pushed to be in the right valve position, the charge is finished, the port P is communicated with the port T, when the port a is lower than the spring set pressure of the two-way three-way pilot operated directional valve 4 due to implementation of braking, the two-way three-way pilot operated directional valve 4 is switched to the left valve position, the pressure at the accumulator 3 is unloaded, and the two-way three-way pilot operated directional valve 5 is switched to the left valve position. Wherein, the set pressure of the two-position two-way pilot operated directional valve 4 is the initial pressure of filling, and the set pressure of the first sequence valve 2 is the stop pressure of filling. The existing liquid filling valve has the technical problems that the existing liquid filling valve is required to be composed of a plurality of groups of valve elements, is complex in structure and high in cost, and has weak pressure maintaining capability, namely a sliding valve structure is arranged between a first sequence valve 2 and a two-position two-way hydraulic control reversing valve 4, an energy accumulator 3 is adopted for pressure maintaining, leakage is easy to occur, frequent liquid filling is caused, and in addition, a pressure maintaining measure does not exist at an opening A connected with the energy accumulator 3. On the other hand, engineering vehicles, such as off-road tire cranes, container front cranes, and the like, generally employ all-hydraulic steering and braking. As shown in fig. 2, the existing hydraulic steering brake system in the industry is generally in a serial structure, when the system works, a main pump provides pressure oil and preferentially flows to a charging valve, the charging valve firstly charges the accumulator to supply the brake system, and when the pressure reaches a specified pressure, a valve position is switched, and the oil flows to the steering system again. The braking system and the steering system generally have respective flow distribution valves with similar functions, the respective flow distribution valves generate throttling loss in the system, the energy consumption of the system is high, and the integration level of the hydraulic steering braking system is low. In view of the above, it is necessary to provide a charging valve with a simple structure, low cost and strong pressure maintaining capability, and it is also necessary to provide a hydraulic steering brake system with a simple structure, high integration level and small pressure loss. Disclosure of Invention The invention aims to provide a liquid filling valve with a simple structure, low cost and strong pressure maintaining capability, a hydraulic steering braking system with a simple structure, high integration level and small pressure loss based on the liquid filling valve, the hydraulic steering braking system can simultaneously provide high-pressure oil for the braking system and the steering system by utilizing the liquid filling valve and a load feedback loop, the integration level of the system is higher, and a third aim of the invention is to provide an engineering vehicle applying the hydraulic steering braking system. The technical scheme is that the liquid filling valve comprises a priority valve and a pilot unloading valve, wherein an LS port of the priority valve is connected with a P port of the pilot unloading valve, a second one-way valve and a pressure maintaining device are sequentially arranged on a passage from the CF port of