Electro-hydraulic reverse proportional brake valve and control method

Abstract

The invention discloses an electro-hydraulic reverse proportional brake valve and a control method, belongs to the field of hydraulic brake systems, and solves the problem that an existing brake valve cannot meet the remote control requirement of a high-risk occasion. The reverse proportional brake valve comprises a valve body and a valve element which is located in the valve body and can slide in the axial direction, a working oil port, an oil inlet and an oil drainage port are formed in the side wall of the valve body, a valve cavity isolated from the outside of the valve body is formed in the valve body, the valve cavity is communicated with the working oil port, the oil inlet and the oil drainage port, the working oil port is communicated with a brake, and the oil drainage port is communicated with the brake. The oil drainage port is communicated with the oil tank, the valve element is arranged in the valve cavity and slides along the inner wall of the valve cavity, and a proportional electromagnet used for driving the valve element to move upwards is arranged below the valve body. According to the electro-hydraulic reverse proportional brake valve and the control method, remote control can be achieved, the condition of a brake system can be monitored and diagnosed in real time, and the brake safety is improved.

Description

Technical Field

[0001] The invention relates to the field of hydraulic brake systems, and in particular to an electro-hydraulic reverse proportional brake valve and a control method thereof. Background Art

[0002] The brake system is an important part of engineering vehicles, and is crucial to the safety of life and property of drivers and the efficiency of vehicle production operations. The existing hydraulic brake system mainly includes hydraulic pumps, overflow valves, filling valves, accumulators, brake valves and brakes, etc. During operation, the hydraulic oil output by the hydraulic pump is supplied to the accumulator through the filling valve. The filling valve ensures that the hydraulic oil pressure in the accumulator is always maintained between the upper and lower limit pressures of the filling valve, which can meet the needs of multiple braking and ensure the reliability of braking.

[0003] At present, hydraulic brake valves widely used in mining transport vehicles and engineering vehicles are mainly divided into two types:

[0004] First: Series full-power hydraulic brake valve, referred to as brake valve, is mainly used in hydraulic brake-spring release brake dual-circuit brake system. When the vehicle needs to stop, step on the brake valve pedal, the brake valve increases the output pressure proportionally, the high-pressure oil stored in the accumulator is released and acts on the piston in the brake. Under the action of the pressure oil, the brake overcomes the spring force and forces the piston to squeeze the friction plate, thereby applying the brake. When the brake valve pedal is released, the high-pressure oil entering the brake piston cavity returns to the oil tank through the brake valve. At the same time, the spring force resets the piston and separates the friction plate, thereby releasing the brake. The brake valve core is a series structure up and down, and the brake system is a dual-circuit form. The front wheel brake and the rear wheel brake are each controlled by one circuit. If one of the circuits fails, the other circuit can still work normally, making the vehicle braking safe and reliable.

[0005] Second: Reverse-adjustable full hydraulic brake valve, referred to as reverse brake valve, is mainly used in spring brake-hydraulic release brake system. When the vehicle is running normally, the reverse brake valve outputs the maximum brake pressure to the brake piston, and forces the friction plate to separate by squeezing the piston, so that the brake is completely released; when the vehicle needs to stop, step on the reverse brake valve pedal, the reverse brake valve reduces the output pressure in proportion, the hydraulic oil pressure in the brake is reduced, the piston is acted upon by the spring force, and the high-pressure oil in the piston cavity is squeezed back into the oil tank. At the same time, the piston forces the friction plates to squeeze and rub against each other, thereby applying the brake. If any part of the brake system fails and causes pressure loss, the brake can automatically apply the brake to ensure the safety of the vehicle.

[0006] The main problems with the brake valve or reverse brake valve used in the traditional hydraulic brake system are as follows:

[0007] 1. For large engineering vehicles with heavy weight or heavy load, the vehicle is long and the distance between the axles is large. If the pressure oil output by the brake valve or reverse brake valve is directly delivered to the brakes of each axle of the vehicle to generate braking force, it will inevitably cause problems such as longer braking response time and uncoordinated braking between the axles, resulting in braking lag, increased braking distance and reduced safety. To solve the above problems, most of them add relay valves to the hydraulic brake system, but the relay valve has a complex structure and needs to be opened by pilot control oil alone, which makes the pipeline of the hydraulic brake system complex and the cost high.

[0008] 2. The working environment of mining transport vehicles is very harsh. They often drive on roads with a lot of dust and water accumulation. At the same time, they run for a long time in excavation working faces with poor visibility and prone to accidents such as roof collapse and rock spalling. These harsh factors seriously threaten the health and life safety of drivers. The existing brake valve or reverse brake valve is based on manual brake operation. The operator must operate on the equipment, which poses a great safety hazard.

[0009] 3. During driving, you will often encounter various road sections, road surfaces and road conditions. You need to implement scientific braking strategies according to the specific surrounding environment at that time to ensure that the wheels do not lock or skid, and to implement reliable braking to stop the vehicle. Both the brake valve and the reverse brake valve can only be adjusted by increasing the braking force, and cannot reduce the braking force by staged relief. This unidirectionality limits the driver's ability to finely adjust the braking force, especially in situations where precise control of the braking force is required, such as parking or avoiding accidental collisions. This limitation will be more obvious.

[0010] At present, with the improvement of the carrying capacity and working requirements of mining transport vehicles and engineering vehicles, engineering vehicles are developing towards large-scale. The braking system must ensure good braking performance under various working conditions. Especially in the construction of high-risk occasions, remote operation and control are more required, and the operation is easy and reliable to ensure driving safety and braking reliability. Summary of the invention

[0011] The technical problem to be solved by the present invention is to provide an electro-hydraulic reverse proportional brake valve and a control method in view of the above-mentioned deficiencies in the prior art, which can realize remote control, monitor and diagnose the condition of the brake system in real time, improve braking safety, and have the effects of anti-pollution, high reliability, sensitive braking, flexible control, easy operation and fast response speed.

[0012] The technical solution adopted in the present invention is: an electro-hydraulic reverse proportional brake valve, comprising a valve body and a valve core axially slidable in the valve body, a working oil port, an oil inlet port and an oil drain port are provided on the side wall of the valve body, a valve cavity isolated from the outside of the valve body is formed inside the valve body, the valve cavity is connected with the working oil port, the oil inlet port and the oil drain port, the working oil port is connected with the brake, the oil drain port is connected with the oil tank, the valve core is arranged in the valve cavity and slides along the inner wall of the valve cavity, a proportional electromagnet for driving the valve core to move upward is provided under the valve body, a spring for driving the valve core to move downward is provided above the valve body, a side channel is provided on the side wall of the valve body, one end of the side channel is connected with the oil drain port, and the other end is connected with the lower part of the valve core.

[0013] As a further improvement, a second plug, a gasket and a spring seat are provided above the valve body, the second plug is fixedly connected to the upper part of the valve body, the spring seat is arranged in the second plug, one end of the spring is sleeved on the spring seat, and the other end abuts against the gasket, and the gasket abuts against the upper step of the valve core.

[0014] Furthermore, a second sealing ring for internal sealing is provided between the valve body and the proportional electromagnet, an O-ring for external sealing is provided between the valve body and the proportional electromagnet, and a first sealing ring is provided between the second plug and the valve body.

[0015] Furthermore, a filter screen is provided at the working oil mouth passage, a fastening sleeve is provided on one side of the filter screen, a hole shoulder is provided at the opening end of the working oil mouth passage, and the filter screen is installed between the hole shoulder and the end of the fastening sleeve.

[0016] Furthermore, an upper blind hole and a lower blind hole are respectively provided at the upper and lower ends of the valve core, a damping hole is provided on the cylindrical side wall corresponding to the lower blind hole, and an oil return hole and an exhaust hole connected thereto are provided on the cylindrical side wall corresponding to the upper blind hole.

[0017] Furthermore, it also includes a feedback rod, a push rod, a limit rod, a pressure ring and a transition block, wherein the feedback rod is partially inserted into the lower blind hole of the valve core, the lower part of the feedback rod is connected to the limit rod, the upper part of the feedback rod and the push rod are movably installed in the lower blind hole of the valve core and generate relative sliding, the pressure ring is arranged below the limit rod and connected thereto, and the push rod (102) contacts the lower step of the valve core through the transition block.

[0018] Furthermore, the valve core is provided with a plurality of annular grooves, the outer wall of the valve core is provided with a first circumferential boss at the circumference, the first circumferential boss is movably mounted on the side wall between the oil inlet and the working oil port, the valve core is also provided with a second circumferential boss, the second circumferential boss is mounted on the side wall between the oil drain port and the working oil port of the valve body.

[0019] A control method for an electro-hydraulic reverse proportional brake valve, wherein a sensor senses a position change caused by a pedal force, generates a corresponding signal and sends it to an electronic system, and the electronic system controls a proportional solenoid, which converts different DC signals into different electromagnetic forces and outputs them to a valve core as control energy of the valve core. The control valve part realizes a working pressure regulation function. As the current decreases, the electromagnetic force gradually weakens, and the pressure generated by the hydraulic oil in the feedback channel of the blind hole at the bottom of the valve core and the working oil port gradually increases until the hydraulic pressure forms a force balance with the electromagnetic force and the spring force, thereby realizing the regulating effect of the electrical signal on the outlet pressure.

[0020] Furthermore, when the vehicle is running normally, the maximum current is passed through the proportional solenoid, generating an electromagnetic force proportional to the input current acting on the push rod of the proportional solenoid. The push rod overcomes the spring force of the spring, so that the oil inlet and the working oil port are completely closed, and the hydraulic oil cannot enter the working oil port through the oil inlet. The oil drain port is completely opened, and the hydraulic oil in the working oil port and the blind hole at the bottom of the valve core enters the oil tank through the oil drain port, and the brake is in a completely released state.

[0021] Furthermore, when the vehicle needs to brake, the proportional solenoid begins to reduce the input current, and the spring pushes the valve core to move toward the proportional solenoid. At this time, the hydraulic oil flows into the working oil port through the oil inlet, and the hydraulic oil at the working oil port enters the feedback channel formed by the blind hole at the bottom of the valve core through the damping hole and acts on the feedback rod. The feedback rod presses against the limit rod to form an upward feedback liquid pressure. The valve core is acted on by the feedback liquid pressure and the electromagnetic force of the proportional solenoid. When the electromagnetic force and the feedback liquid pressure are equal to the spring force, the system reaches a stable boost or equilibrium state. At this time, the hydraulic oil pressure in the brake increases proportionally, and the vehicle begins to brake. When the proportional solenoid gradually reduces the input current until the current is zero, so that the output pressure of its working oil port is at the maximum working pressure, the maximum brake pressure output by the electro-hydraulic reverse proportional brake valve flows to the brake piston to achieve complete braking.

[0022] Beneficial Effects

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The electro-hydraulic reverse proportional brake valve of the present invention combines the electronic and hydraulic systems, with the electronic system providing control and the hydraulic system providing power. By adjusting and arranging the components and utilizing the programmable electronic control unit drive signal, the brake pressure is output proportionally, so that the system can be remotely controlled, and the brake system status can be monitored and diagnosed in real time, thus avoiding the problem of slow brake response of traditional hydraulic brakes in such applications. At the same time, it has the advantages of anti-pollution, low cost and fast response speed.

[0025] 2. The electro-hydraulic reverse proportional brake valve of the present invention can be installed near the brake position. By using electrical signals instead of hydraulics for long-distance transmission, the brake valve is kept away from the cab, which saves space and keeps the noise of the hydraulic pipeline away from the operator, thereby improving the system performance and the driver's working environment.

[0026] 3. The electro-hydraulic reverse proportional brake valve of the present invention has high proportional control characteristics, fast response speed, compact structure, and is easy to process and assemble. It is suitable for providing hydraulic power for normal braking and emergency braking after power loss in electric control brakes, anti-skid brake systems, traction brake control systems, etc. in mining transport vehicles and engineering vehicles, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 It is a partial schematic diagram of the left view of the present invention.

[0029] Figure 3 It is a partial schematic diagram of the main view of the present invention.

[0030] Figure 4 It is a main cross-sectional schematic diagram of the valve core of the present invention.

[0031] Figure 5 Schematic diagram of the feedback lever of the present invention.

[0032] Figure 6 It is a schematic diagram of the valve core opening position of the present invention.

[0033] Figure 7 It is a schematic diagram of the valve core of the present invention when it has a certain stroke.

[0034] Figure 8 It is a schematic diagram of the valve core limit position of the present invention.

[0035] Figure numerals: proportional solenoid 1, valve body 2, pressure ring 3, limit rod 4, transition block 5, fastening sleeve 6, filter screen 7, valve core 8, gasket 9, first sealing ring 10, second plug 11, spring seat 12, spring 13, first plug 14, push rod 15, feedback rod 16, second sealing ring 17, O-ring 18, push rod 102, oil inlet 201, oil drain port 202, working oil port 203, valve chamber 204, side channel 205, exhaust hole 801, upper blind hole 802, oil return hole 803, damping hole 804, lower blind hole 805, first circumferential boss 806, second circumferential boss 807, upper step 809, lower step 808, pressure equalizing groove 161. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the specific embodiments in the accompanying drawings.

[0037] See also Figure 1-8 As shown, an electro-hydraulic reverse proportional brake valve of the present invention comprises a valve body 2 and a valve core 8 axially slidable in the valve body 2, a working oil port 203, an oil inlet 201 and an oil drain port 202 are provided on the side wall of the valve body 2, a valve cavity 204 isolated from the outside of the valve body is formed inside the valve body 2, the valve cavity 204 is communicated with the working oil port 203, the oil inlet 201 and the oil drain port 202, the working oil port 203 is communicated with the brake, the oil drain port 202 is communicated with the oil tank, the valve core 8 is arranged in the valve cavity 204 and slides along the inner wall of the valve cavity 204, a proportional electromagnet 1 for driving the valve core 8 to move upward is provided under the valve body 2, a spring 13 for driving the valve core 8 to move downward is provided above the valve body 2, a side channel 205 is provided on the side wall of the valve body, one end of the side channel 205 is communicated with the oil drain port 202, and the other end of the side channel 205 is communicated with the oil drain port 202. The end is connected to the lower part of the valve core 8. The proportional solenoid 1 is the electro-mechanical conversion element of the electro-hydraulic reverse proportional brake valve, which converts the electrical signal input by the proportional control amplifier into a force signal. It has a horizontal displacement-force characteristic that is independent of displacement. A certain control current corresponds to a certain output force, that is, the output force is proportional to the input current. Changing the current can proportionally change the output force, thereby controlling the size of the valve core 8 opening and keeping the electro-hydraulic reverse proportional brake valve outlet pressure continuously changing with the electrical signal. The electronic system provides control and the hydraulic system provides power. Through the adjustment and arrangement of components and the use of programmable electronic control unit drive signals, the proportional output brake pressure allows the system to be remotely controlled, and can monitor and diagnose the brake system status in real time, avoiding the problem of slow brake response of traditional hydraulic brakes in this application. At the same time, it has the advantages of anti-pollution, low cost and fast response speed.

[0038] Specifically, a second plug 11, a gasket 9 and a spring seat 12 are provided above the valve body 2. The second plug 11 is fixedly connected to the upper part of the valve body 2. The spring seat 12 is arranged in the second plug 11. One end of the spring 13 is sleeved on the spring seat 12, and the other end abuts against the gasket 9. The gasket 9 abuts against the upper step 809 of the valve core 8. The gasket 9 can limit the initial pre-compression stroke of the spring 13, and the spring seat 12 plays a guiding role for the spring 13.

[0039] Preferably, a second sealing ring 17 for internal sealing is provided between the valve body and the proportional electromagnet, an O-ring 18 for external sealing is provided between the valve body and the proportional electromagnet, and a first sealing ring 10 is provided between the second plug 11 and the valve body 2. The first sealing ring 10 has a sealing function. The first sealing ring 10 can block the hydraulic oil from flowing out of the gap between the valve body 2 and the second plug 11, and the second sealing ring 17 can block the hydraulic oil from flowing out of the gap between the proportional electromagnet 1 and the valve body 2 to prevent the hydraulic oil from leaking and affecting the working performance of the electro-hydraulic reverse proportional brake valve. The O-ring 18 is used to prevent external dust particles from entering the proportional electromagnet 1.

[0040] Furthermore, a filter screen 7 is provided at the cavity of the working oil port 203, a fastening sleeve 6 is provided on one side of the filter screen 7, a hole shoulder is provided at the open end of the cavity of the working oil port 203, the filter screen 7 is installed between the hole shoulder and the end of the fastening sleeve 6, a flange is provided at the edge of the open end of the filter screen 7, the flange is clamped between the hole shoulder and the end of the fastening sleeve 6, the filter screen 7 is fixed by the cooperation of the hole shoulder and the fastening sleeve 6, the filter screen 7 filters the hydraulic oil that returns to the oil tank of the brake and flows through the flow channel in the valve core 8 and the damping hole 804, thereby removing impurities in the hydraulic oil, effectively preventing the damping hole 804 and the valve core 8 from being blocked, and ensuring that the electro-hydraulic reverse proportional brake valve can work normally under complex working conditions.

[0041] Furthermore, an upper blind hole 802 and a lower blind hole 805 are respectively provided at the upper and lower ends of the valve core 8, and a damping hole 804 is provided on the side wall of the cylinder corresponding to the lower blind hole 805. The damping hole 804 can damp the movement of the valve core 8, thereby avoiding the vibration of the valve core 8 and improving the stability of the electro-hydraulic reverse proportional brake valve. The lower blind hole 805 and the damping hole 804 form a valve core feedback channel. The number of the damping hole 804 is one, and an oil return hole 803 and an exhaust hole 801 connected thereto are provided on the side wall of the cylinder corresponding to the upper blind hole 802, which can guide the gas in the upper valve cavity 204 of the valve body to flow out from the exhaust hole 801 through the upper blind hole 802 of the valve core and the oil return hole 803, so that the residual gas in the valve cavity 204 is discharged from the oil drain port 202, thereby preventing the gas from accumulating at one end of the valve core and causing the electro-hydraulic reverse proportional brake valve to produce abnormal noise.

[0042] Furthermore, it also includes a feedback rod 16, a push rod 15, a limit rod 4, a pressure ring 3 and a transition block 15, wherein the feedback rod 16 is partially inserted into the lower blind hole 805 of the valve core 8, the lower part of the feedback rod 16 is connected to the limit rod 4, the upper part of the feedback rod 16 and the push rod 15 are movably installed in the lower blind hole 805 of the valve core 8 and generate relative sliding, the pressure ring 3 is arranged below the limit rod 4 and connected thereto, the push rod 102 contacts the lower step 808 of the valve core 8 through the transition block 15, and the pressure ring 3 The limit rod 4 fixes and limits the feedback rod 16 to move downward through the proportional electromagnet 1. The proportional electromagnet 1 contacts the step 808 at the bottom of the valve core through the transition block 5. The feedback rod 16 is a cylindrical structure. The feedback rod 16 extends in the valve core and moves along the longitudinal axis of the feedback rod. The feedback rod 16 also has a pressure equalizing groove 161. The number of the pressure equalizing grooves 161 is greater than 2. The pressure equalizing grooves 161 can effectively reduce the radial unbalanced force on the feedback rod 16 and avoid the feedback rod 16 from getting stuck.

[0043] Furthermore, the valve core 8 is provided with a plurality of annular grooves. When the valve core 8 is installed in the valve cavity 204 of the valve body, the connection between the working oil port 203 cavity and the oil inlet 201 cavity or the oil drain port 202 cavity on the valve body can be opened by moving the valve core 8. A first circumferential boss 806 is provided at the circumference of the outer wall of the valve core 8. The first circumferential boss 806 is movably installed at the side wall between the oil inlet 201 and the working oil port 203, and can be moved along the longitudinal axis direction of the oil inlet cavity channel and the working oil cavity channel. The valve core 8 is also provided with a second circumferential boss 807. The second circumferential boss 807 is installed at the side wall between the oil drain port 202 and the working oil port 203 of the valve body, and can be moved along the longitudinal axis direction of the working oil cavity channel and the oil drain cavity channel.

[0044] A control method for an electro-hydraulic reverse proportional brake valve, wherein a sensor senses a position change caused by a pedal force, generates a corresponding signal and sends it to an electronic system, and the electronic system controls a proportional solenoid 1, which converts different DC signals into different electromagnetic forces and outputs them to a valve core 8 as control energy for the valve core 8. The control valve part realizes a working pressure regulation function. As the current decreases, the electromagnetic force gradually weakens, and the pressure generated by the hydraulic oil in the feedback channel of the blind hole 805 at the bottom of the valve core and the working oil port 203 gradually increases until the hydraulic pressure forms a force balance with the electromagnetic force and the spring force, thereby realizing the regulating effect of the electrical signal on the outlet pressure.

[0045] Reference below Figure 6-8 The working process of the electro-hydraulic reverse proportional brake valve according to an embodiment of the present invention is described, and the direction indicated by the arrow in the figure is the flow direction of the hydraulic oil.

[0046] Reference Figure 6As shown, when the vehicle is running normally, the maximum current is passed through the proportional electromagnet 1, and an electromagnetic force proportional to the input current is generated to act on the push rod 102 of the proportional electromagnet. The push rod 102 overcomes the spring force of the spring 13, so that the oil inlet 201 and the working oil port 203 are completely closed, and the hydraulic oil cannot enter the working oil port 203 through the oil inlet 201. The oil drain port 202 is completely opened, and the hydraulic oil in the working oil port 203 and the blind hole 805 at the bottom of the valve core enters the oil tank through the oil drain port 202, and the brake is in a completely released state.

[0047] Reference Figure 8 As shown, when the proportional solenoid 1 gradually reduces the input current until the current is zero and the electromagnetic force is zero, the first circumferential boss 806 of the valve core opens the valve ports of the oil inlet 201 and the working oil port 203 to the maximum, and the hydraulic oil flows from the oil inlet 201 cavity to the working oil port 203 cavity. The hydraulic oil in the working oil port 203 cavity enters the feedback channel formed by the blind hole 805 at the lower part of the valve core through the damping hole 804 on the valve core and acts on the feedback rod 16. The feedback rod 16 presses against the limit rod 4 to generate an upward feedback liquid pressure on the valve core 8. At this moment, there is a liquid pressure on the inner surface of the feedback channel cavity on the valve core 8, and a spring force acts on the upper step 809 of the valve core. The feedback liquid pressure is balanced with the spring force and is the same as the pressure in the working oil port 203 cavity, so that the output pressure of the working oil port 203 is at the maximum working pressure; the maximum brake pressure output by the electro-hydraulic reverse proportional brake valve flows to the brake piston to achieve complete braking. Furthermore, when the vehicle needs to brake, the proportional solenoid 1 begins to reduce the input current, and the spring 13 pushes the valve core 8 to move in the direction of the proportional solenoid 1. The first circumferential boss 806 of the valve core increases the valve openings of the oil inlet 201 and the working oil port 203, and the second circumferential boss 807 reduces the valve openings of the working oil port 203 and the oil drain port 202, and the output pressure of the working oil port 203 increases. At this time, the hydraulic oil flows into the working oil port 203 through the oil inlet 201, and the hydraulic oil at the working oil port 203 enters the feedback channel formed by the blind hole 805 at the lower part of the valve core through the damping hole 804 and acts on the feedback rod 16. The feedback rod 16 presses against the limit rod to form an upward feedback liquid pressure. The valve core 8 is acted upon by the feedback liquid pressure and the electromagnetic force of the proportional solenoid 1. When the electromagnetic force and the feedback liquid pressure are equal to the spring force, the system reaches a stable pressurization or equilibrium state. At this time, the hydraulic oil pressure in the brake increases proportionally, and the vehicle begins to brake.

[0048] Reference Figure 8As shown, when the proportional solenoid 1 gradually reduces the input current until the current is zero and the electromagnetic force is zero, the first circumferential boss 806 of the valve core opens the valve ports of the oil inlet 201 and the working oil port 203 to the maximum, and the hydraulic oil flows from the oil inlet 201 cavity to the working oil port 203 cavity. The hydraulic oil in the working oil port 203 cavity enters the feedback channel formed by the blind hole 805 at the lower part of the valve core through the damping hole 804 on the valve core and acts on the feedback rod 16. The feedback rod 16 presses against the limit rod 4 to generate an upward feedback liquid pressure on the valve core 8. At this moment, there is a liquid pressure on the inner surface of the feedback channel cavity on the valve core 8, and a spring force acts on the upper step 809 of the valve core. The feedback liquid pressure is balanced with the spring force and is the same as the pressure in the working oil port 203 cavity, so that the output pressure of the working oil port 203 is at the maximum working pressure; the maximum brake pressure output by the electro-hydraulic reverse proportional brake valve flows to the brake piston to achieve complete braking.

[0049] When an electro-hydraulic reverse proportional brake valve of the present embodiment is in use, the proportional solenoid 1 converts different DC signals into different electromagnetic forces and outputs them to the valve core 8 as the control energy of the valve core 8. The control valve part realizes the working pressure regulation function. As the current decreases, the electromagnetic force gradually weakens, and the pressure generated by the hydraulic oil in the feedback channel of the blind hole 805 at the bottom of the valve core and the working oil port 203 will gradually increase until the hydraulic pressure forms a force balance with the electromagnetic force and the spring force, thereby realizing the regulating effect of the electrical signal on the outlet pressure, thereby realizing the control provided by the electronic system and the power provided by the hydraulic system. Through the adjustment and arrangement of components, the programmable electronic control unit drive signal is used to output proportional brake pressure, so that the system can be remotely controlled and can be monitored and diagnosed in real time. The brake valve can be installed close to the brake position, and the long-distance transmission is carried out by replacing the hydraulic pressure with the electrical signal, so that the brake valve is far away from the cab, and the space is saved, and the noise of the hydraulic pipeline is far away from the operator, which improves the system performance and the driver's working environment. In addition, the brake valve has high proportional control characteristics, fast response speed, compact structure, and easy processing and assembly. It is suitable for normal braking and emergency braking after power loss of electric control brakes, anti-skid brake systems, traction brake control systems, etc. in mining transport vehicles and engineering vehicles to provide hydraulic power, and has a wide range of applications.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. An electro-hydraulic reverse proportional brake valve, characterized in that: The invention comprises a valve body (2) and a valve core (8) which is axially slidable in the valve body (2); a working oil port (203), an oil inlet (201) and an oil drain port (202) are provided on the side wall of the valve body (2); a valve cavity (204) which is isolated from the outside of the valve body is formed inside the valve body (2); the valve cavity (204) is connected to the working oil port (203), the oil inlet (201) and the oil drain port (202); the working oil port (203) is connected to the brake; the oil drain port (202) is connected to the brake; and the oil drain port (203) is connected to the brake. 02) is connected to the oil tank, the valve core (8) is arranged in the valve cavity (204) and slides along the inner wall of the valve cavity (204), a proportional electromagnet (1) for driving the valve core (8) to move upward is provided below the valve body (2), a spring (13) for driving the valve core (8) to move downward is provided above the valve body (2), a side channel (205) is opened on the side wall of the valve body, one end of the side channel (205) is connected to the oil drain port (202), and the other end is connected to the lower part of the valve core (8).

2. An electro-hydraulic reverse proportional brake valve according to claim 1, characterized in that: A second plug (11), a gasket (9) and a spring seat (12) are provided above the valve body (2); the second plug (11) is fixedly connected to the upper part of the valve body (2); the spring seat (12) is arranged in the second plug (11); one end of the spring (13) is sleeved on the spring seat (12) and the other end abuts against the gasket (9); the gasket (9) abuts against the upper step (809) of the valve core (8).

3. The electro-hydraulic reverse proportional brake valve according to claim 1, characterized in that: A second sealing ring (17) for internal sealing is arranged between the valve body and the proportional electromagnet, an O-ring (18) for external sealing is arranged between the valve body and the proportional electromagnet, and a first sealing ring (10) is arranged between the second plug (11) and the valve body (2).

4. The electro-hydraulic reverse proportional brake valve according to claim 1, characterized in that: A filter screen (7) is provided at the cavity of the working oil port (203), a fastening sleeve (6) is provided on one side of the filter screen (7), a hole shoulder is provided at the opening end of the cavity of the working oil port (203), and the filter screen (7) is installed between the hole shoulder and the end of the fastening sleeve (6).

5. The electro-hydraulic reverse proportional brake valve according to claim 1, characterized in that: The valve core (8) is provided with an upper blind hole (802) and a lower blind hole (805) at the upper and lower ends respectively; a damping hole (804) is provided on the cylindrical side wall corresponding to the lower blind hole (805); and an oil return hole (803) and an exhaust hole (801) communicating with the upper blind hole (802) are provided on the cylindrical side wall corresponding to the upper blind hole (802).

6. An electro-hydraulic reverse proportional brake valve according to claim 5, characterized in that: It also includes a feedback rod (16), a push rod (15), a limit rod (4), a pressure ring (3) and a transition block (15), wherein the feedback rod (16) is partially inserted into the lower blind hole (805) of the valve core (8), the lower part of the feedback rod (16) is connected to the limit rod (4), the upper part of the feedback rod (16) and the push rod (15) are movably installed in the lower blind hole (805) of the valve core (8) and generate relative sliding, the pressure ring (3) is arranged below the limit rod (4) and connected thereto, and the push rod (102) contacts the lower step (808) of the valve core (8) through the transition block (15).

7. The electro-hydraulic reverse proportional brake valve according to claim 5, characterized in that: The valve core (8) is provided with a plurality of annular grooves, and the outer wall of the valve core (8) is provided with a first circumferential boss (806) at the circumference, and the first circumferential boss (806) is movably installed at the side wall between the oil inlet (201) and the working oil port (203). The valve core (8) is also provided with a second circumferential boss (807), and the second circumferential boss (807) is installed at the side wall between the oil drain port (202) and the working oil port (203) of the valve body.

8. A control method for an electro-hydraulic reverse proportional brake valve, characterized in that: The sensor senses the position change caused by the pedal force and generates a corresponding signal and sends it to the electronic system. The electronic system controls the proportional solenoid (1). The proportional solenoid (1) converts different DC signals into different electromagnetic forces and outputs them to the valve core (8). As the control energy of the valve core (8), the control valve part realizes the working pressure regulation function. As the current decreases, the electromagnetic force gradually weakens, and the pressure generated by the hydraulic oil in the feedback channel of the blind hole (805) at the bottom of the valve core and the working oil port (203) gradually increases until the hydraulic pressure forms a force balance with the electromagnetic force and the spring force, thereby realizing the regulation effect of the electrical signal on the outlet pressure.

9. The control method of an electro-hydraulic reverse proportional brake valve according to claim 8, characterized in that: When the vehicle is running normally, the maximum current is passed through the proportional electromagnet (1), generating an electromagnetic force proportional to the input current to act on the push rod (102) of the proportional electromagnet. The push rod (102) overcomes the spring force of the spring (13), so that the oil inlet (201) and the working oil port (203) are completely closed, and the hydraulic oil cannot enter the working oil port (203) through the oil inlet (201). The oil drain port (202) is completely opened, and the hydraulic oil in the working oil port (203) and the blind hole (805) at the bottom of the valve core enters the oil tank through the oil drain port (202), and the brake is in a completely released state.

10. The control method of an electro-hydraulic reverse proportional brake valve according to claim 8, characterized in that: When the vehicle needs to brake, the proportional electromagnet (1) starts to reduce the input current, and the spring (13) pushes the valve core (8) to move in the direction of the proportional electromagnet (1). At this time, the hydraulic oil flows into the working oil port (203) through the oil inlet (201). The hydraulic oil at the working oil port (203) enters the feedback channel formed by the blind hole (805) at the bottom of the valve core through the damping hole (804) and acts on the feedback rod (16). The feedback rod (16) presses against the limit rod to form an upward feedback hydraulic pressure. The valve core (8) is acted by the feedback hydraulic pressure and the electromagnetic force of the proportional electromagnet (1). When the electromagnetic force and the feedback hydraulic pressure are equal to the spring force, the system reaches a stable pressurization or equilibrium state. At this time, the hydraulic oil pressure in the brake increases proportionally, and the vehicle starts to brake. When the proportional electromagnet (1) gradually reduces the input current until the current is zero, so that the output pressure of its working oil port (203) is at the maximum working pressure, the maximum brake pressure output by the electro-hydraulic reverse proportional brake valve flows to the brake piston, achieving full braking.

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