Load-sensitive hydraulic brake valve and load-sensitive hydraulic system thereof

Abstract

The invention relates to the field of tire type walking equipment, and discloses a load-sensitive hydraulic brake valve and a load-sensitive hydraulic system thereof, and the load-sensitive hydraulic system comprises the load-sensitive hydraulic brake valve, a load-sensitive pump, a priority valve, a steering hydraulic system, a working hydraulic system, a shuttle valve and corresponding connecting pipelines; a P port, an A port, a B port, a T port, an LS1 port, an LS port, a low-pressure alarm pressure switch and a brake lamp pressure switch are arranged outside the load-sensitive hydraulic brake valve. According to the system, full-hydraulic dynamic braking can be achieved on equipment without a prefill valve, the equipment efficiency is improved, the installation cost is reduced, the energy consumption is reduced, and the service life is prolonged. Wherein the load-sensitive hydraulic brake valve integrates a brake function, a pressure maintaining function, a high-low pressure switching function, a pressure signal selection function and a pressure alarm function; the invention has the advantages of fast braking response, low noise, low failure rate, high safety coefficient, compact structure, low cost, low energy consumption and long service life.

Description

Technical Field

[0001] The invention relates to the technical field of tire-type walking equipment, in particular to a load-sensitive hydraulic brake valve and a load-sensitive hydraulic system thereof. Background Art

[0002] The brake system is an important part of tire-type walking equipment, which is crucial to the life and property safety of the driver and the production efficiency of the vehicle. The main components of the existing full hydraulic power brake system include hydraulic pump, charging valve, brake valve, accumulator and corresponding connecting pipelines, etc. The full hydraulic power brake system has the advantages of fast braking response, low noise, low failure rate and high safety factor.

[0003] Taking all factors into consideration, the oil of the full hydraulic power brake system, steering hydraulic system and working hydraulic system of tire-type walking equipment is generally taken from the same hydraulic pump. The energy consumed by the brake system and steering hydraulic system is negligible compared with other systems. However, the brake system and steering hydraulic system are both installation devices, but they occupy a very important position and are an indispensable part of tire-type walking equipment.

[0004] Medium and large tire-type walking equipment usually need hydraulic pumps to provide instantaneous large flow when working. In order to reduce energy consumption, their hydraulic systems generally adopt load-sensitive hydraulic systems. The main characteristics of load-sensitive hydraulic systems are: the load-sensitive pump outputs the flow and pressure required for the work according to the work instructions, and when the hydraulic systems are not working, the load-sensitive pump only outputs the flow that meets the internal leakage of the hydraulic system, greatly reducing energy loss.

[0005] Therefore, how to apply a full hydraulic power brake system on equipment equipped with a load-sensitive hydraulic system while saving energy and extending service life has become an urgent problem that needs to be solved in the industry. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a load-sensitive hydraulic brake valve and a load-sensitive hydraulic system thereof, which solve the problem of how to apply a full hydraulic power brake system on equipment equipped with a load-sensitive hydraulic system, thereby realizing full hydraulic power braking without the need to equip a filling valve, thereby improving equipment efficiency, reducing manufacturing costs, reducing energy consumption, and extending service life.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a load-sensitive hydraulic brake valve, the load-sensitive hydraulic brake valve has a P port, an A port, a B port, a T port, an LS1 port, an LS port, a low-pressure alarm pressure switch and a brake light pressure switch on the outside; The P port is the filling oil inlet port, connected to the CF port of the priority valve; Port A is a pressure-maintaining oil port, connected to an accumulator; The B port is a brake oil output port, connected to the axle brake; The T port is an oil return port, connected to the oil tank; The LS1 port is a feedback port, connected to the LS port of the steering gear; The LS port is a feedback port, connected to the LS port of the priority valve and the induction oil port of the load sensing pump; The low pressure alarm pressure switch is used for low pressure alarm and is connected to an alarm; The brake light pressure switch is used to control the brake light and is connected to the brake light.

[0008] Preferably, the load-sensitive hydraulic brake valve is internally integrated with a one-way valve, a shuttle valve, a high and low unloading valve, and a brake valve group. The one-way valve is used to maintain the pressure of the brake system to ensure that the oil in the accumulator connected to the A port cannot be depressurized too quickly; The shuttle valve is used to select the larger of the pressure of the LS1 port and the pressure of the P port, and output it from the LS port, and finally transmit the pressure to the priority valve and the load sensing pump; The high and low pressure unloading valve is used to ensure that the accumulator connected to the A port is always maintained within a certain pressure range; The brake valve group is used to control the brake output pressure to ensure that the output pressure of the B port can meet the driver's deceleration or parking needs.

[0009] Preferably, the opening pressure of the one-way valve is a preset value, which is used to maintain the pressure of the accumulator oil.

[0010] Preferably, the high-low pressure unloading valve has a high-pressure unloading pressure value and a low-pressure unloading pressure value, and the high-low pressure unloading valve performs an unloading operation when the pressure of the accumulator connected to the A port is higher than the high-pressure unloading pressure value, and stops the unloading operation when the pressure of the accumulator connected to the A port is lower than the low-pressure unloading pressure value.

[0011] Preferably, the brake valve group includes a valve core, a spring and a valve seat, and the output pressure of the B port is adjusted by the movement of the valve core and the elastic deformation of the spring.

[0012] Preferably, a load-sensitive hydraulic system comprises the load-sensitive hydraulic brake valve, and also comprises a load-sensitive pump, a priority valve, a steering hydraulic system, a working hydraulic system, a shuttle valve and corresponding connecting pipelines; The priority valve is a load-sensitive priority valve having an LS oil port, and the LS port of the priority valve is connected to the LS port of the brake valve; The priority valve further has a CF port and an EF port, wherein the CF port of the priority valve is connected to the P port of the steering hydraulic system and the P port of the load-sensing hydraulic brake valve, and the EF port of the priority valve is connected to the P port of the working hydraulic system; The steering hydraulic system is a load-sensitive steering hydraulic system having an LS oil port, and the LS port of the steering hydraulic system is connected to the LS1 port of the brake valve; The working hydraulic system is a load-sensitive hydraulic system and has an LS oil port; The oil outlet of the load sensing pump is connected to the P port of the priority valve; The load-sensing pump also has an induction oil port for sensing the pressure signal transmitted from the LS port of each hydraulic system, so as to adjust the displacement of the load-sensing pump to meet the working requirements.

[0013] Preferably, the load-sensitive pump adjusts its displacement by adjusting its swash plate angle or other adjustment methods according to the pressure signal sensed by the sensing oil port.

[0014] Preferably, the steering hydraulic system includes a steering gear, the LS port of the steering gear is connected to the LS1 port of the load-sensitive hydraulic brake valve, and the P port of the steering hydraulic system receives oil from the CF port of the priority valve for load-sensitive steering.

[0015] Preferably, the working hydraulic system feeds back a pressure signal to the sensing oil port of the load sensing pump through its LS oil port to adjust the displacement of the load sensing pump.

[0016] Preferably, the shuttle valve is used to compare and select the pressures in different hydraulic circuits and transmit the larger pressure signal to the corresponding component; The priority valve adjusts the flow distribution from its CF port to the steering hydraulic system and the flow distribution from its EF port to the working hydraulic system according to the pressure signal received by the LS port, so as to give priority to meeting the demand of the steering hydraulic system.

[0017] Working principle: Filling process: When the system is started, the load sensing pump draws oil from the tank and delivers the oil to the P port of the priority valve. The priority valve delivers the oil to the P port of the steering hydraulic system and the P port of the load sensing hydraulic brake valve through the CF port.

[0018] For the load-sensitive hydraulic brake valve, when the pressure of the accumulator connected to port A drops below the set low-pressure unloading pressure value, the high-low pressure unloading valve closes. At this time, the pressure oil at port P will flow through the internal damping hole and shuttle valve in sequence, and then output from port LS. A part of the pressure oil acts on the sensing oil port of the load-sensitive pump through the shuttle valve and other components, causing the load-sensitive pump to increase the flow output. The other part of the pressure oil acts on the LS port of the priority valve, causing the pressure at the CF port of the priority valve to rise, thereby filling the accumulator.

[0019] When the accumulator pressure reaches the set high-pressure unloading pressure value, the high-pressure and low-pressure unloading valves open. The pressure oil at the P port flows back to the tank through the throttle hole, the high-pressure and low-pressure unloading valves, and the T port. At the same time, the pressure oil at the LS port of the priority valve and the load-sensing pump sensing oil port will also flow back to the tank through the corresponding pipelines, the CF port of the priority valve is depressurized, and the output flow of the load-sensing pump is reduced.

[0020] Steering process: When the steering hydraulic system is working, the LS port of the steering gear (LS port of the steering hydraulic system) outputs pressure signal oil, which is transmitted to the LS1 port of the load sensing hydraulic brake valve through the connecting pipeline.

[0021] The shuttle valve inside the load sensing hydraulic brake valve selects the larger of the pressure at the LS1 port (from the steering hydraulic system) and the pressure at the P port, and outputs it from the LS port. This pressure signal acts on the LS port of the priority valve and the sensing oil port of the load sensing pump.

[0022] The load-sensing pump increases displacement and outputs more oil by adjusting the swash plate angle according to the pressure signal of the sensing oil port. The priority valve distributes more oil from the CF port to the steering hydraulic system according to the pressure signal of the LS port, ensuring the supply of hydraulic oil required for steering operation and realizing load-sensitive steering.

[0023] Braking process: Under normal circumstances, the brake valve group does not work, the B port and T port of the load-sensing hydraulic brake valve are connected, and the axle brake pressure is zero.

[0024] When braking is required, the driver operates the brake valve group. The valve core in the brake valve group moves under the action of the driver's operating force, connecting port A and port B. The oil in the accumulator enters the axle brake through port A, the brake valve group, and port B to achieve braking.

[0025] During the movement of the valve core of the brake valve group, the output pressure of port B is controlled by the elastic deformation of the spring, and the output pressure is proportional to the driver's operating force. When the maximum output pressure set by the brake valve group is reached, the brake output pressure is maintained at the maximum value.

[0026] At the same time, when the pressure at port B rises to the pressure value set by the brake light pressure switch, the brake light pressure switch closes, causing the brake light to light up.

[0027] Working hydraulic system: When the working hydraulic system is working, its P port receives the oil from the EF port of the priority valve for working. The LS port of the working hydraulic system outputs the pressure signal oil, which acts on the sensing oil port of the load sensing pump through the shuttle valve and the connecting pipeline.

[0028] The load-sensing pump adjusts the displacement according to the pressure signal of the sensing oil port to meet the working requirements of the working hydraulic system. At the same time, the shuttle valve compares the pressure signals of the LS port of the load-sensing hydraulic brake valve and the LS port of the working hydraulic system, and transmits the larger pressure signal to the sensing oil port of the load-sensing pump. The priority valve adjusts the flow distribution of the CF port and the EF port according to the pressure signal of its LS port, giving priority to meeting the needs of the steering hydraulic system, and the operation of the working hydraulic system will not interfere with the normal operation of the steering hydraulic system.

[0029] Pressure signal transmission and flow distribution: The entire system transmits pressure signals through the LS ports of each component. For example, the LS ports of the steering hydraulic system, load sensing hydraulic brake valve and working hydraulic system transmit pressure signals to the sensing oil port of the load sensing pump and the LS port of the priority valve.

[0030] The load-sensing pump adjusts the displacement according to the pressure signal of the sensing oil port, and the priority valve adjusts the flow distribution from the CF port to the steering hydraulic system and from the EF port to the working hydraulic system according to the pressure signal of the LS port. The shuttle valve plays the role of selecting and transmitting the larger pressure signal, ensuring that the system can reasonably distribute the oil flow according to the pressure requirements under different working conditions, and realize the efficient and stable operation of the entire hydraulic system.

[0031] The present invention provides a load-sensitive hydraulic brake valve and a load-sensitive hydraulic system thereof. The present invention provides the following beneficial effects: 1. The present invention comprehensively considers the full hydraulic power brake system with the existing load-sensitive hydraulic system and steering hydraulic system, eliminates the filling valve, and the oil source of the full hydraulic power brake system is taken from the existing priority valve CF port of the equipment, and the pressure feedback signal is selected through the shuttle valve on the load-sensitive brake valve, and the pressure feedback signal is transmitted to the priority valve and the load-sensitive pump to realize the filling and energy replenishment of the full hydraulic power brake system or the steering work of the steering hydraulic system.

[0032] 2. The present invention integrates multiple functions into the load-sensitive hydraulic brake valve, reducing the number of system components and pipeline connections, making the entire system structure more compact, occupying less space, and facilitating the layout and installation of equipment.

[0033] 3. The present invention eliminates the filling valve, reduces the number of parts and components, and reduces the procurement cost; at the same time, the compact structure reduces the piping and installation costs.

[0034] 4. The present invention avoids unnecessary energy loss, improves energy utilization efficiency and reduces energy consumption by automatically adjusting the displacement of the load-sensitive pump according to the pressure signals of each system and reasonably distributing the flow rate of the priority valve.

[0035] 5. The present invention comprehensively considers the full hydraulic power brake system with the existing load-sensitive hydraulic system and steering hydraulic system, eliminates the filling valve, and solves the problems of complex system structure and high cost; through reasonable pressure feedback and flow distribution, the coordinated work of various systems is achieved, reducing energy consumption.

[0036] 6. Compared with the prior art, the present invention has significant advantages such as compact structure, low cost and low energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the load-sensing hydraulic system of the present invention.

[0038] Figure 2 It is a schematic diagram of the load-sensing hydraulic brake valve of the present invention.

[0039] Among them, the oil tank 1; the load-sensitive pump 2; the priority valve 3; the load-sensitive hydraulic brake valve 4; the one-way valve 4-1; the brake valve component 4-2; the brake light pressure switch 4-3; the low-pressure alarm pressure switch 4-4; the shuttle valve 4-5; the high- and low-pressure unloading valves 4-6; the throttle hole 4-7; the accumulator 5; the axle brake 6; the steering hydraulic system 7; the working hydraulic system 8; the shuttle valve 9. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Please refer to the attached Figure 1 -Attached Figure 2 An embodiment of the present invention provides a load-sensitive hydraulic brake valve and a load-sensitive hydraulic system thereof. The load-sensitive hydraulic system includes a load-sensitive hydraulic brake valve 4, a load-sensitive pump 2, a priority valve 3, an accumulator 5, an axle brake 6, a steering hydraulic system 7, a working hydraulic system 8 and a shuttle valve 9, etc.

[0042] Specifically, the load-sensing hydraulic brake valve 4 is provided with a P port, an A port, a B port, a T port, an LS1 port, an LS port, a low-pressure alarm pressure switch 4-4 and a brake light pressure switch 4-3 on the outside. The P port is used as a filling oil inlet port, connected to the CF port of the priority valve 3 through a pipeline; the A port is used as a pressure-maintaining oil port, connected to the accumulator 5 through a pipeline; the B port is used as a brake output oil port, connected to the axle brake 6 through a pipeline; the T port is used as an oil return port, connected to the oil tank 1; the LS1 port is used as a feedback port, connected to the LS port of the steering gear located in the steering hydraulic system 7 through a pipeline; the LS port is used as a feedback port, connected to the LS port of the priority valve 3 and the sensing oil port of the load-sensing pump 2 through a pipeline. The low-pressure alarm pressure switch 4-4 is connected to the alarm through a line, used to send an alarm signal when the pressure is too low; the brake light pressure switch 4-3 is connected to the brake light through a line, used to control the lighting of the brake light.

[0043] The load-sensitive hydraulic brake valve 4 internally integrates a one-way valve 4-1, a shuttle valve 4-5, a high-low pressure unloading valve 4-6, and a brake valve group including a brake valve component 4-2. The one-way valve 4-1 is set in the oil circuit between the A port and the accumulator 5, and its opening pressure is a preset value to ensure that the oil in the accumulator 5 will not be depressurized too quickly, thereby realizing the pressure-maintaining function of the brake system. The two input ports of the shuttle valve 4-5 are respectively connected to the LS1 port and the P port, and the output port is connected to the LS port, which is used to select the larger of the LS1 port pressure and the P port pressure, and transmit the pressure signal to the priority valve 3 and the load-sensitive pump 2 through the LS port. The high-low pressure unloading valve 4-6 is set in the oil circuit between the P port and the T port, and has a high-pressure unloading pressure value and a low-pressure unloading pressure value, which is used to maintain the pressure of the accumulator 5 within a certain range. The brake valve group is composed of a valve core, a spring and a valve seat, represented by the brake valve component 4-2, which is arranged in the oil circuit between port A and port B. The output pressure of port B is adjusted by the movement of the valve core in the valve seat and the elastic deformation of the spring to meet the braking needs of the driver.

[0044] Load sensing pump 2: The oil outlet is connected to the P port of the priority valve 3 through a pipeline, sucking oil from the oil tank 1 and supplying oil to the priority valve 3. At the same time, its sensing oil port receives the pressure signal transmitted from the LS port of each hydraulic system through the pipeline, and adjusts the displacement by adjusting the swash plate angle or other adjustment methods according to the signal to meet the system working requirements.

[0045] Priority valve 3: It is a load-sensitive priority valve with LS port, CF port and EF port. The LS port is connected to the LS port of the load-sensitive hydraulic brake valve 4 through a pipeline to receive a pressure signal. The CF port is connected to the P port of the steering hydraulic system 7 and the P port of the load-sensitive hydraulic brake valve 4 through a pipeline, and the EF port is connected to the P port of the working hydraulic system 8 through a pipeline. The priority valve 3 adjusts the flow distribution from the CF port to the steering hydraulic system 7 and from the EF port to the working hydraulic system 8 according to the pressure signal received at the LS port, and gives priority to meeting the needs of the steering hydraulic system 7.

[0046] Steering hydraulic system 7: It is a load-sensitive steering hydraulic system with LS port and P port. The LS port is connected to the LS1 port of the load-sensitive hydraulic brake valve 4 through a pipeline to output pressure signal oil. The P port receives oil from the CF port of the priority valve 3 through a pipeline to achieve load-sensitive steering. The LS port of the steering gear is connected to the LS1 port of the load-sensitive hydraulic brake valve 4, and outputs pressure signal oil when working.

[0047] Working hydraulic system 8: It belongs to the load-sensitive hydraulic system and has LS port and P port. The P port is connected to the EF port of the priority valve 3 through a pipeline to receive oil for controlling various working devices, such as bucket lifting, etc. When working, its LS port outputs pressure signal oil, which acts on the sensing oil port of the load-sensitive pump 2 through the shuttle valve 9 and the corresponding connecting pipeline to adjust the displacement of the load-sensitive pump 2.

[0048] Shuttle valve 9: The two input ports are connected to the LS port of the load-sensing hydraulic brake valve 4 and the LS port of the working hydraulic system 8 through pipelines respectively, and the output port is connected to the sensing oil port of the load-sensing pump 2 through a pipeline, which is used to select the pressure signal oil with a larger pressure value between the two and transmit it to the sensing oil port of the load-sensing pump 2, so that the load-sensing pump 2 adjusts the displacement according to demand.

[0049] The operating principle of the above-mentioned load-sensing hydraulic system is as follows: 1. Filling process: After the system is started, the load sensing pump 2 sucks oil from the oil tank 1 and delivers the oil to the P port of the priority valve 3. The priority valve 3 delivers the oil to the P port of the steering hydraulic system 7 and the P port of the load sensing hydraulic brake valve 4 through the CF port.

[0050] When the pressure of the accumulator 5 connected to the A port of the load-sensing hydraulic brake valve 4 drops below the set low-pressure unloading pressure value, the high-low pressure unloading valve 4-6 is closed. At this time, the pressure oil at the P port of the load-sensing hydraulic brake valve 4 flows through the throttle hole 4-7 and the shuttle valve 4-5 in sequence, and then outputs from the LS port. A part of the pressure oil acts on the sensing oil port of the load-sensing pump 2 through the shuttle valve 9 and other components, causing the load-sensing pump 2 to increase the flow output. The other part of the pressure oil acts on the LS port of the priority valve 3, causing the pressure at the CF port of the priority valve 3 to rise, thereby filling the accumulator 5.

[0051] When the pressure of the accumulator 5 reaches the set high-pressure unloading pressure value, the high-low pressure unloading valve 4-6 opens. The pressure oil at the P port flows back to the oil tank 1 through the throttle hole 4-7, the high-low pressure unloading valve 4-6, and the T port. At the same time, the pressure oil at the LS port of the priority valve 3 and the sensing oil port of the load-sensing pump 2 also flows back to the oil tank 1 through the corresponding pipelines, the CF port of the priority valve 3 is unloaded, and the output flow of the load-sensing pump 2 is reduced. In this way, the automatic control of the pressure of the accumulator 5 is achieved, maintaining it within a certain range, and ensuring the stable operation of the braking system.

[0052] 2. Turning process: When the steering hydraulic system 7 is working, the LS port of the steering gear outputs pressure signal oil, and the signal oil is transmitted to the LS1 port of the load sensing hydraulic brake valve 4 through the pipeline.

[0053] The shuttle valve 4-5 inside the load sensing hydraulic brake valve 4 selects the larger of the pressure from the steering hydraulic system 7 at the LS1 port and the pressure at the P port, and outputs it from the LS port. This pressure signal acts on the LS port of the priority valve 3 and the sensing oil port of the load sensing pump 2.

[0054] The load-sensing pump 2 increases the displacement and outputs more oil by adjusting the swash plate angle according to the pressure signal of the sensing oil port. The priority valve 3 distributes more oil from the CF port to the steering hydraulic system 7 according to the pressure signal of the LS port, ensuring the supply of hydraulic oil required for steering operation, realizing load-sensitive steering, and making the steering operation more sensitive and efficient.

[0055] 3. Braking process: Under normal circumstances, the brake valve component 4-2 of the brake valve group does not work, the B port and the T port of the load-sensing hydraulic brake valve 4 are connected, the pressure of the axle brake 6 is zero, and the equipment runs normally.

[0056] When braking is required, the driver operates the brake valve member 4-2 of the brake valve group. The valve core in the brake valve group moves under the action of the driver's operating force, so that port A and port B are connected. The oil in the accumulator 5 enters the axle brake 6 through port A, the brake valve member 4-2 of the brake valve group, and port B to achieve braking.

[0057] During the movement of the valve core of the brake valve component 4-2 of the brake valve group, the output pressure of port B is controlled by the elastic deformation of the spring, and the output pressure is proportional to the driver's operating force. When the maximum output pressure set by the brake valve group is reached, the brake output pressure is maintained at the maximum value. At the same time, when the pressure of port B rises to the pressure value set by the brake light pressure switch 4-3, the brake light pressure switch 4-3 is closed, so that the brake light is turned on to alert surrounding vehicles and pedestrians. This braking method can accurately control the braking intensity according to the driver's needs and ensure driving safety.

[0058] 4. Working process of hydraulic system: When the working hydraulic system 8 is working, its P port receives the oil from the EF port of the priority valve 3 to drive the working device. The LS port of the working hydraulic system 8 outputs the pressure signal oil, which acts on the sensing oil port of the load sensing pump 2 through the shuttle valve 9 and the connecting pipeline.

[0059] The load sensing pump 2 adjusts the displacement according to the pressure signal of the sensing oil port to meet the working requirements of the working hydraulic system 8. At the same time, the shuttle valve 9 compares the pressure signals of the LS port of the load sensing hydraulic brake valve 4 and the LS port of the working hydraulic system 8, and transmits the larger pressure signal to the sensing oil port of the load sensing pump 2. The priority valve 3 adjusts the flow distribution of the CF port and the EF port according to the pressure signal of its LS port, giving priority to meeting the requirements of the steering hydraulic system 7, and the operation of the working hydraulic system 8 will not interfere with the normal operation of the steering hydraulic system 7, ensuring that each system can operate stably and collaboratively.

[0060] In the prior art, the full hydraulic power brake system, the load-sensitive hydraulic system and the steering hydraulic system may be relatively independent, resulting in a complex structure, high cost and high energy consumption. The present invention comprehensively considers the full hydraulic power brake system with the existing load-sensitive hydraulic system and steering hydraulic system, eliminates the filling valve, and solves the problem of complex system structure and high cost. Through reasonable pressure feedback and flow distribution, the coordinated work of each system is achieved, and energy consumption is reduced.

[0061] The present invention has the following advantages: Compact structure: Integrating multiple functions into the load-sensing hydraulic brake valve 4 reduces the number of system components and pipeline connections, making the entire system structure more compact, occupying less space, and facilitating the layout and installation of equipment.

[0062] Low cost: Eliminating the filling valve reduces the number of parts and reduces procurement costs. At the same time, the compact structure reduces piping and installation costs.

[0063] Low energy consumption: The load-sensitive pump 2 automatically adjusts the displacement according to the pressure signals of each system, and the priority valve 3 reasonably distributes the flow, thus avoiding unnecessary energy loss, improving energy utilization efficiency and reducing energy consumption.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A load-sensitive hydraulic brake valve, characterized in that: The load-sensing hydraulic brake valve has a P port, an A port, a B port, a T port, an LS1 port, an LS port, a low-pressure alarm pressure switch and a brake light pressure switch on the outside; The P port is the filling oil inlet port, connected to the CF port of the priority valve; Port A is a pressure-maintaining oil port, connected to an accumulator; The B port is a brake oil output port, connected to the axle brake; The T port is an oil return port, connected to the oil tank; The LS1 port is a feedback port, connected to the LS port of the steering gear; The LS port is a feedback port, connected to the LS port of the priority valve and the induction oil port of the load sensing pump; The low pressure alarm pressure switch is used for low pressure alarm and is connected to an alarm; The brake light pressure switch is used to connect the brake light and control the brake light.

2. A load-sensing hydraulic brake valve according to claim 1, characterized in that: The load-sensitive hydraulic brake valve is internally integrated with a one-way valve, a shuttle valve, a high and low unloading valve, and a brake valve group. The one-way valve is used to maintain the pressure of the brake system to ensure that the oil in the accumulator connected to the A port cannot be depressurized too quickly; The shuttle valve is used to select the larger of the pressure of the LS1 port and the pressure of the P port, and output it from the LS port, and finally transmit the pressure to the priority valve and the load sensing pump; The high and low pressure unloading valve is used to ensure that the accumulator connected to the A port is always maintained within a certain pressure range; The brake valve group is used to control the brake output pressure to ensure that the output pressure of the B port can meet the driver's deceleration or parking needs.

3. A load-sensing hydraulic brake valve according to claim 2, characterized in that: The opening pressure of the one-way valve is a preset value, which is used to control the pressure-maintaining function of the accumulator oil.

4. A load-sensing hydraulic brake valve according to claim 2, characterized in that: The high-low pressure unloading valve has a high-pressure unloading pressure value and a low-pressure unloading pressure value. The high-low pressure unloading valve performs an unloading operation when the pressure of the accumulator connected to the A port is higher than the high-pressure unloading pressure value, and stops the unloading operation when the pressure of the accumulator connected to the A port is lower than the low-pressure unloading pressure value.

5. A load-sensing hydraulic brake valve according to claim 1, characterized in that: The brake valve group includes a valve core, a spring and a valve seat, and the output pressure of the B port is adjusted by the movement of the valve core and the elastic deformation of the spring.

6. A load-sensitive hydraulic system, characterized in that: The load-sensing hydraulic brake valve according to any one of claims 1 to 5 further comprises a load-sensing pump, a priority valve, a steering hydraulic system, a working hydraulic system, a shuttle valve and corresponding connecting pipelines; The priority valve is a load-sensitive priority valve having an LS oil port, and the LS port of the priority valve is connected to the LS port of the brake valve; The priority valve further has a CF port and an EF port, wherein the CF port of the priority valve is connected to the P port of the steering hydraulic system and the P port of the load-sensing hydraulic brake valve, and the EF port of the priority valve is connected to the P port of the working hydraulic system; The steering hydraulic system is a load-sensitive steering hydraulic system having an LS oil port, and the LS port of the steering hydraulic system is connected to the LS1 port of the brake valve; The working hydraulic system is a load-sensitive hydraulic system and has an LS oil port; The oil outlet of the load sensing pump is connected to the P port of the priority valve; The load-sensing pump also has an induction oil port for sensing the pressure signal transmitted from the LS port of each hydraulic system, so as to adjust the displacement of the load-sensing pump to meet the working requirements.

7. A load sensing hydraulic system according to claim 6, characterized in that: The load-sensing pump adjusts its displacement by adjusting its swash plate angle or other adjustment methods according to the pressure signal sensed by the sensing oil port.

8. A load sensing hydraulic system according to claim 6, characterized in that: The steering hydraulic system includes a steering gear, the LS port of the steering gear is connected to the LS1 port of the load-sensing hydraulic brake valve, and the P port of the steering hydraulic system receives oil from the CF port of the priority valve for load-sensing steering.

9. A load sensing hydraulic system according to claim 6, characterized in that: The working hydraulic system feeds back the pressure signal to the sensing oil port of the load sensing pump through its LS oil port to adjust the displacement of the load sensing pump.

10. A load sensing hydraulic system according to claim 6, characterized in that: The shuttle valve is used to compare and select the pressures in different hydraulic circuits and transmit the larger pressure signal to the corresponding component; The priority valve adjusts the flow distribution from its CF port to the steering hydraulic system and the flow distribution from its EF port to the working hydraulic system according to the pressure signal received by the LS port, so as to give priority to meeting the demand of the steering hydraulic system.

Images