Electric forklift braking hydraulic system and control method thereof

Abstract

The invention discloses an electric forklift braking hydraulic system and a control method thereof, relates to the technical field of electric forklift braking hydraulic systems, and aims at solving the problem that an existing electric forklift braking hydraulic system cannot achieve the rapid, stable and energy-saving braking liquid filling function. The oil supply pipeline is provided with a gear pump, the diverter valve is communicated with the brake system through a first branch, the first branch is provided with an integrated brake prefill valve group, the integrated brake prefill valve group comprises an energy accumulator and an electromagnetic valve connected with the energy accumulator, and the electromagnetic valve is used for controlling the on-off of the first branch; the integrated brake prefill valve group further comprises a pressure monitoring assembly used for monitoring the pressure value of the energy accumulator in real time, and the gear pump, the flow divider valve, the electromagnetic valve and the pressure monitoring assembly are all in signal connection with a controller. Through the arrangement, the response speed and reliability of braking are improved.

Description

Technical Field

[0001] This invention relates to the field of electric forklift braking hydraulic systems, and more specifically, to an electric forklift braking hydraulic system and its control method. Background Technology

[0002] As industrial material handling vehicles, forklifts require essential functions such as steering, braking, lifting, and tilting. Counterbalance electric forklifts play a core role in the material handling field, and the performance of their hydraulic systems directly affects the overall efficiency, energy consumption, and safety of the vehicle.

[0003] In existing technologies, electric forklifts operate their braking functions very frequently during actual use. However, the hydraulic lines for the braking function are mostly located in the bypass of the main pump. This means that when the electric forklift's hydraulic system is running, pressurized hydraulic fluid is prioritized for steering and mast movements, while the braking system can only obtain excess fluid for filling and maintaining pressure after other actions are completed. The braking system's demand for pressurized hydraulic fluid is immediate. When frequent braking causes a drop in accumulator pressure, the electric forklift's hydraulic system must first complete filling before subsequent braking operations can be performed. This process introduces a certain delay, which, in severe cases, may affect driving safety.

[0004] Furthermore, the braking function relies primarily on a series of distributed valve assemblies, such as individual filling valves, throttle valves, and accumulators. This multi-valve arrangement not only occupies a significant amount of forklift installation space, but the numerous pipe fittings and hydraulic hose connections also increase the risk of leaks and malfunctions, leading to increased costs. When the forklift requires frequent braking, pressure and flow fluctuations occur among these distributed valve assemblies, further increasing the energy consumption of the electric forklift's hydraulic system.

[0005] Therefore, how to solve the problem that the existing electric forklift brake hydraulic system cannot achieve fast, stable and energy-saving brake fluid filling function is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an electric forklift braking hydraulic system that can ensure that the braking system can maintain a stable oil pressure after frequent braking, thereby improving the braking response speed and the reliability of braking effect.

[0007] Another objective of this invention is to provide a control method for the above-mentioned electric forklift braking hydraulic system, which improves braking response speed and enhances driving safety.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An electric forklift braking hydraulic system includes an oil tank connected to a flow divider valve via an oil supply line. The oil supply line is equipped with a gear pump. The flow divider valve is connected to the braking system via a first branch. The first branch is equipped with an integrated brake filling valve assembly. The integrated brake filling valve assembly includes an accumulator and a solenoid valve connected to the accumulator. The solenoid valve is used to control the on / off state of the first branch. The integrated brake filling valve assembly also includes a pressure monitoring component for real-time monitoring of the pressure value of the accumulator. The gear pump, flow divider valve, solenoid valve, and pressure monitoring component are all signal-connected to a controller.

[0010] Preferably, the diverter valve is connected to the multi-way directional valve through the first pipeline, and the multi-way directional valve is connected to the controller via signal.

[0011] Preferably, the pressure monitoring component includes a first pressure sensor and a second pressure sensor. When the first pressure sensor detects that the pressure value of the accumulator is lower than a first set pressure value, the controller controls the solenoid valve to open. When the second pressure sensor detects that the pressure value of the accumulator is lower than a second set pressure value, the controller issues an alarm signal, indicating that the second set pressure value is lower than the first set pressure value.

[0012] Preferably, the braking system includes a brake and a brake valve, the brake valve being used to control the accumulator to supply oil to the brake, and the brake valve being signal-connected to the controller.

[0013] Preferably, a filter is installed on the oil supply line, the filter is located between the oil tank and the gear pump, and the filter is connected to the controller signal.

[0014] Preferably, the integrated brake filling valve assembly and the brake system are connected to the oil tank via a return oil line, and a filter is installed on the return oil line.

[0015] Preferably, the fuel tank is equipped with an air filter for air circulation, and the air filter is connected to the controller signal.

[0016] Preferably, the oil tank is equipped with a dipstick for measuring the volume of oil in the tank.

[0017] A control method for an electric forklift braking hydraulic system, applied to the aforementioned electric forklift braking hydraulic system, the control method comprising:

[0018] Control the start-up of the gear pump and flow divider valve;

[0019] The operating status of the solenoid valve is controlled based on the received pressure signal;

[0020] Open the brake valve to apply the brakes.

[0021] Preferably, the process of controlling the operating state of the solenoid valve based on the received pressure signal includes:

[0022] When the first pressure sensor detects that the pressure value of the accumulator is lower than the first set pressure value, the controller controls the solenoid valve to close and begins to charge the accumulator with liquid.

[0023] When the first pressure sensor detects that the pressure value of the accumulator is higher than the first set pressure value, the controller controls the solenoid valve to de-energize, and the filling ends.

[0024] When the second pressure sensor detects that the pressure value of the accumulator is lower than the second set pressure value, the controller issues an alarm signal.

[0025] The electric forklift braking hydraulic system provided by this invention includes an oil tank, a gear pump, a flow divider valve, a braking system, an integrated brake filling valve assembly, and a controller. Specifically, the gear pump, flow divider valve, solenoid valve, and pressure monitoring components are all signal-connected to the controller. The controller enables intelligent control of the entire electric forklift braking hydraulic system, improving automation and control precision. The oil tank is connected to the flow divider valve via a supply line, ensuring a stable supply of hydraulic fluid to all components and guaranteeing normal system operation. The supply line is equipped with a gear pump, which efficiently delivers hydraulic fluid from the oil tank to the flow divider valve, ensuring a stable supply and improving system response speed. The flow divider valve is connected to the braking system via a first branch, ensuring an independent hydraulic fluid supply to the braking system and avoiding interference with other systems (such as the steering system), thus improving the reliability and response speed of the braking system.

[0026] The first branch circuit is equipped with an integrated brake fluid filling valve assembly, which includes an accumulator and a solenoid valve connected to the accumulator. The solenoid valve controls the on / off state of the first branch circuit. It responds quickly to controller signals, rapidly controlling the on / off state of the first branch. When fluid filling is required for braking, the solenoid valve opens immediately, allowing pressurized oil in the supply line containing the diverter valve to flow rapidly to the accumulator, significantly shortening the filling time and improving braking immediacy. When fluid filling is not required, the solenoid valve closes immediately, allowing pressurized oil in the supply line containing the diverter valve to flow directly back to the fuel tank, thereby improving system efficiency. The integrated brake fluid filling valve assembly also includes a pressure monitoring component for real-time monitoring of the accumulator's pressure. This component ensures the accumulator remains within a suitable pressure range, improving system stability and reliability. By monitoring the pressure in real-time, the controller can automatically adjust the solenoid valve's state according to actual needs, achieving intelligent management and increasing the system's automation level.

[0027] The electric forklift brake hydraulic system designed in the above manner significantly improves braking response speed and reliability through the coordinated operation of the integrated brake filling valve assembly and the flow divider valve, thereby enhancing driving safety. The integrated brake filling valve assembly integrates multiple functions into one module, reducing the overall size and weight of the system, while also reducing manufacturing and maintenance costs. It also reduces the complexity of the electric forklift brake hydraulic system, lowers the risk of leakage, improves the reliability and safety of the system, and saves installation space and costs. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the electric forklift braking hydraulic system provided by the present invention;

[0030] Figure 2 for Figure 1 A magnified view of a portion of the image;

[0031] Figure 3 This is a schematic diagram of the integrated brake fluid filling valve assembly provided by the present invention.

[0032] Figure 4 for Figure 1 A schematic diagram of another embodiment;

[0033] Figure 5 A flowchart illustrating the steps of the control method for the electric forklift braking hydraulic system provided by the present invention.

[0034] Figure label:

[0035] 1-Fuel tank;

[0036] 2- Gear pump;

[0037] 3-Multi-way directional valve;

[0038] 4-Flow divider valve;

[0039] 5-Brake system, 51-Brake, 52-Brake valve;

[0040] 6-Integrated brake fluid filling valve assembly, 61-Accumulator, 62-Solenoid valve, 63-First pressure sensor, 64-Second pressure sensor;

[0041] 7-Filter;

[0042] 8-Air filter;

[0043] 9-Patent dipstick;

[0044] 10-Steering gear;

[0045] 11-Speed ​​limiting valve. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] The core of this invention is to provide an electric forklift braking hydraulic system that ensures the braking system 5 maintains stable hydraulic pressure even after frequent braking, thereby improving braking response speed and the reliability of braking effect. Another core aspect of this invention is to provide a control method including the aforementioned electric forklift braking hydraulic system, which improves braking response speed and enhances driving safety.

[0049] Please refer to Figure 1 , Figure 2 and Figure 3 An electric forklift braking hydraulic system includes an oil tank 1, a gear pump 2, a flow divider valve 4, a braking system 5, an integrated brake filling valve group 6, and a controller.

[0050] Specifically, gear pump 2, flow divider valve 4, solenoid valve 62, and pressure monitoring components are all connected to the controller. The controller enables intelligent control of the entire electric forklift's braking hydraulic system, improving automation and control precision. The oil tank 1 is connected to the flow divider valve 4 via a supply line, ensuring a stable supply of oil to all components and guaranteeing normal system operation. The supply line is equipped with gear pump 2, which efficiently delivers oil from the oil tank 1 to the flow divider valve 4, ensuring a stable oil supply and improving system response speed. The flow divider valve 4 is connected to the braking system 5 via a first branch, ensuring the braking system 5 has an independent oil supply, avoiding interference with other systems (such as the steering system), and improving the reliability and response speed of the braking system 5.

[0051] The flow divider valve 4 is located in the oil supply line and is connected to the braking system 5 through the first branch. The flow divider valve 4 allows the braking system 5 to operate independently of other functions (such as steering, lifting, etc.), reducing mutual interference between different functions and improving the stability of the system. The flow divider valve 4 can accurately distribute the oil to the braking system 5, ensuring that the braking system 5 receives sufficient oil flow, thereby improving the reliability and response speed of braking. The first branch is equipped with an integrated brake fluid filling valve assembly 6, which includes an accumulator 61 and a solenoid valve 62 connected to the accumulator 61. The solenoid valve 62 controls the on / off state of the first branch. The solenoid valve 62 can quickly respond to the controller's signal and rapidly control the on / off state of the first branch. When fluid filling for braking is required, the solenoid valve 62 can open immediately, allowing the pressurized oil in the oil supply line where the diverter valve 4 is located to flow rapidly to the accumulator 61, significantly shortening the filling time and improving the immediacy of braking. When fluid filling for braking is not required, the solenoid valve 62 can close immediately, allowing the pressurized oil in the oil supply line where the diverter valve 4 is located to flow directly back to the oil tank 1, thereby improving the system's energy efficiency. The integrated brake fluid filling valve assembly 6 also includes a pressure monitoring component for real-time monitoring of the pressure value of the accumulator 61. The pressure monitoring component can monitor the pressure value of the accumulator 61 in real time, ensuring that the accumulator 61 is always maintained within a suitable pressure range, improving the system's stability and reliability. By monitoring the pressure value in real time, the controller can automatically adjust the state of the solenoid valve 62 according to actual needs, realizing intelligent management and improving the automation level of the system.

[0052] By incorporating an integrated brake filling valve assembly 6 in the first branch, the flow of hydraulic fluid to the braking system 5 can be quickly controlled, ensuring that the braking system 5 can obtain pressurized oil instantly when needed. This significantly reduces the time delay in brake filling, improves braking response speed, and effectively solves the driving safety hazards caused by filling delays in existing technologies. The integrated brake filling valve assembly 6 can precisely control the on / off state of the first branch, ensuring that the braking system 5 maintains stable hydraulic pressure even after frequent braking, avoiding brake pressure instability caused by pressure drops in the accumulator 61, thereby improving the reliability of braking performance. The integrated brake filling valve assembly 6 integrates multiple functions into one module, replacing the complex arrangement of distributed valve assemblies in traditional technologies, significantly reducing the overall size and weight of the hydraulic system and saving forklift installation space. The integrated design reduces the number of pipe joints and hydraulic hose connections in traditional hydraulic systems, lowering the risk of leakage and failure due to excessive connection points, and improving system reliability and safety.

[0053] It should be noted that the solenoid valve 62 can quickly respond to the controller's signal and rapidly control the on / off state of the first branch. In traditional hydraulic systems, brake fluid filling requires waiting for other actions to be completed before it can proceed, resulting in a significant time delay. The integrated brake fluid filling valve assembly 6, through the rapid control of the solenoid valve 62, ensures that the braking system 5 can immediately obtain pressurized oil when needed, thereby reducing braking delay and improving driving safety. When filling is not required, the solenoid valve 62 can be immediately closed, avoiding unnecessary oil flow and thus improving system efficiency.

[0054] The direct connection between the solenoid valve 62 and the accumulator 61 further simplifies the system structure and improves the system's sealing and reliability. The integrated brake filling valve assembly 6 integrates the accumulator 61 and the solenoid valve 62 into a single module, significantly reducing the overall size and weight of the system and saving forklift installation space.

[0055] Furthermore, the diverter valve 4 is connected to the multi-way directional valve 3 through the first pipeline, and the multi-way directional valve 3 is connected to the controller signal.

[0056] Through intelligent control of the gear pump 2, multi-way directional valve 3, flow divider valve 4, and integrated brake filling valve assembly 6, the hydraulic system can precisely allocate oil flow and pressure according to actual needs, avoiding increased energy consumption caused by pressure and flow fluctuations between multiple valves and improving the system's energy-saving effect. This hydraulic system, through optimized design and intelligent control, not only improves braking performance but also enhances the overall efficiency and reliability of the system, while reducing costs and maintenance difficulty, enabling the forklift to maintain efficient and stable operation in various application scenarios.

[0057] Please refer to Figure 4In one feasible embodiment, the oil tank 1 is connected to a double gear pump. The oil outlet of the double gear pump is connected to a multi-way directional valve 3 and a flow divider valve 4 through oil supply lines. The design of the double gear pump enables the electric forklift hydraulic system to provide two oil lines simultaneously to meet different functional requirements (such as steering, braking, lifting, etc.). Through the multi-way directional valve 3, the electric forklift hydraulic system can flexibly distribute the oil flow direction, realize the switching and combination of multiple functions, improve the system's versatility and adaptability, and thus improve the overall efficiency of the system.

[0058] The electric forklift brake hydraulic system configured in the above manner significantly improves braking response speed and reliability through the coordinated operation of the integrated brake filling valve assembly 6 and the diverter valve 4, enhancing driving safety. The integrated brake filling valve assembly 6 integrates multiple functions into one module, reducing the overall size and weight of the system, while also reducing manufacturing and maintenance costs. It also reduces the complexity of the electric forklift brake hydraulic system, lowers the risk of leakage, improves the reliability and safety of the system, and saves installation space and costs.

[0059] In the above situation, the pressure monitoring component includes a first pressure sensor 63 and a second pressure sensor 64. When the first pressure sensor 63 detects that the pressure value of the accumulator 61 is lower than the first set pressure value, the controller controls the solenoid valve 62 to open. When the second pressure sensor 64 detects that the pressure value of the accumulator 61 is lower than the second set pressure value, the controller issues an alarm signal, indicating that the second set pressure value is lower than the first set pressure value.

[0060] Understandably, solenoid valve 62 is connected to the controller signal, enabling precise control of the oil flow and pressure according to actual needs. Through precise control, the system can utilize the oil more efficiently during braking, reducing energy consumption caused by pressure and flow fluctuations. This not only improves the system's energy-saving effect but also extends the service life of the hydraulic system.

[0061] Specifically, by setting a first pressure sensor 63 and a second pressure sensor 64, the system can perform dual monitoring of the pressure of the accumulator 61. The first pressure sensor 63 is used for normal fluid filling control, ensuring that the braking system 5 can obtain sufficient pressurized oil in time when needed. The second pressure sensor 64 is used for low-pressure alarm. When the pressure of the accumulator 61 drops to a lower level, an alarm signal is issued in time to remind the operator to take measures to avoid brake failure due to insufficient pressure, which significantly improves the safety of the braking system 5. The first pressure sensor 63 can monitor the pressure value of the accumulator 61 in real time. When the pressure is lower than the first set pressure value, the controller immediately controls the solenoid valve 62 to open and start filling. This precise filling control ensures that the accumulator 61 is always kept within a suitable pressure range, avoiding the decrease in braking performance due to insufficient pressure or overfilling. By monitoring the pressure value in real time, the system can dynamically adjust the filling operation according to the actual working conditions, ensuring that the braking system 5 maintains optimal performance under different working conditions. Through precise pressure monitoring and control, the system only fills the accumulator 61 when the pressure is insufficient, avoiding unnecessary filling operations and reducing the energy consumption of the hydraulic system. The controller can intelligently control the operating status of gear pump 2 based on the feedback signal from the pressure sensor, further optimize the system's energy consumption management, and improve the overall energy efficiency of the system.

[0062] Furthermore, the braking system 5 includes a brake 51 and a brake valve 52. The brake valve 52 is used to control the accumulator 61 to supply oil to the brake 51, and the brake valve 52 is connected to the controller signal.

[0063] It should be noted that the brake valve 52 is connected to the controller signal and can open or close instantly according to the controller's instructions, ensuring that the pressurized oil in the accumulator 61 can quickly flow to the brake 51. This rapid response capability significantly improves the response speed of the braking system 5, reduces braking delay, and enhances driving safety. The controller can precisely control the opening of the brake valve 52 according to actual operating conditions (such as vehicle speed, load, etc.), achieving more precise braking operation and avoiding safety hazards caused by excessive or insufficient braking. The automated control of the brake valve 52 reduces the uncertainty of human operation, ensuring that each braking operation is performed according to the preset program, improving the reliability and consistency of the braking system 5. By precisely controlling the opening and closing of the brake valve 52, the system can avoid unnecessary oil flow, reduce the energy consumption of the hydraulic system, and improve the system's energy efficiency.

[0064] In the above embodiment, a filter 7 is provided on the oil supply line. The filter 7 is located between the oil tank 1 and the gear pump 2, and the filter 7 is connected to the controller signal.

[0065] Understandably, installing filter 7 on the oil supply line filters the hydraulic oil entering gear pump 2, effectively removing impurities and particulate matter, ensuring the cleanliness of the hydraulic oil, and thus improving the overall performance and reliability of the hydraulic system. Clean hydraulic oil reduces wear on critical components such as hydraulic pumps and valve assemblies, extending equipment lifespan and reducing maintenance costs. Filter 7 is connected to the controller signal, enabling real-time monitoring of its operating status (such as differential pressure and blockage). When filter 7 becomes clogged or malfunctions, the controller can promptly issue an alarm signal, reminding operators to perform maintenance or replacement, preventing hydraulic system failures caused by filter 7 blockage, and improving system stability and reliability.

[0066] Based on the above embodiments, the integrated brake filling valve group 6 and the brake system 5 are connected to the oil tank 1 through the return oil line, and the return oil line is equipped with a filter 7.

[0067] It should be noted that the filter 7 installed on the return oil line effectively filters the hydraulic oil returning from the braking system 5 and the integrated brake filling valve assembly 6 to the oil tank 1, removing impurities, particles, and contaminants from the oil. This ensures that the hydraulic oil returning to the oil tank 1 remains clean, improves the overall reliability of the system, and reduces system failures caused by oil contamination. By filtering the return oil, contaminants in the hydraulic oil are reduced, extending the service life of the hydraulic oil, lowering the frequency of hydraulic oil replacement, and saving maintenance costs.

[0068] In the above embodiment, the oil tank 1 is provided with an air filter 8 for connecting air, and the air filter 8 is connected to the controller signal.

[0069] Understandably, the air filter 8 is welded to the upper part of the oil tank 1 to achieve pressure balance between the oil tank 1 and the outside air. The air filter 8 effectively filters the air entering the oil tank 1, removing dust, particles, and contaminants, preventing these impurities from entering the oil tank 1. This maintains the cleanliness of the hydraulic oil, reduces hydraulic oil contamination, extends the service life of the hydraulic oil, lowers the frequency of hydraulic oil replacement, and saves maintenance costs. The air filter 8 is connected to the controller signal, enabling real-time monitoring of its operating status (such as blockage). When the air filter 8 is blocked or malfunctions, the controller can promptly issue an alarm signal, reminding operators to perform maintenance or replacement, avoiding system failures caused by problems with the air filter 8.

[0070] In a preferred embodiment, the oil tank 1 is provided with an oil dipstick 9 for measuring the volume of oil in the oil tank 1.

[0071] It should be noted that the dipstick 9 is threaded to the upper part of the hydraulic cylinder to measure the volume of hydraulic fluid inside the cylinder. The dipstick 9 can measure the volume of hydraulic fluid in the oil tank 1 in real time. By accurately monitoring the hydraulic fluid level, operators can add or replace hydraulic fluid in advance, avoiding system failures due to insufficient fluid or overflow and waste due to excessive fluid, and ensuring that the hydraulic system always operates at the appropriate fluid level.

[0072] Please refer to Figure 5 A control method for an electric forklift braking hydraulic system, applied to the aforementioned electric forklift braking hydraulic system, the control method comprising:

[0073] Step S1: Start the gear pump 2 and the flow divider valve 4;

[0074] Step S2: Control the operating state of solenoid valve 62 according to the received pressure signal;

[0075] Step S3: Open the brake valve 52 to activate the brake 51.

[0076] Understandably, by controlling the activation of gear pump 2 and flow divider valve 4, the hydraulic system can quickly enter a working state, providing sufficient oil pressure to braking system 5. This rapid start-up capability significantly improves braking response speed, reduces braking delay, and enhances driving safety. By precisely controlling the operating state of solenoid valve 62, the system can quickly adjust the oil flow direction according to real-time pressure signals, ensuring that brake 51 can immediately obtain pressurized oil when needed, achieving instant braking. Based on the received pressure signal, the controller can precisely control the operating state of solenoid valve 62, ensuring that the hydraulic system operates within the optimal pressure range, reducing system failures caused by insufficient or excessive pressure, and improving system reliability. Through real-time monitoring by pressure sensors, the system can promptly detect pressure anomalies and take measures to avoid braking system 5 failures due to pressure problems, further enhancing system stability. The controller dynamically adjusts the state of solenoid valve 62 according to real-time pressure signals, ensuring that the hydraulic system maintains optimal performance under different operating conditions. This dynamic adjustment capability improves the system's adaptability and flexibility, ensuring that braking system 5 can operate reliably under various operating conditions. By precisely controlling the operating state of the solenoid valve 62, the system can avoid unnecessary oil flow, reduce the energy consumption of the hydraulic system, and improve the system's energy efficiency.

[0077] By rapidly starting gear pump 2 and flow divider valve 4, and precisely controlling the operating state of solenoid valve 62, braking response speed is significantly improved, braking delay is reduced, and driving safety is enhanced. Precise pressure control and real-time monitoring feedback reduce system failures caused by pressure issues, improving system reliability and stability. Dynamically adjusting the state of solenoid valve 62 ensures the hydraulic system maintains optimal performance under different operating conditions, improving system adaptability and flexibility while reducing energy consumption. Automated control and intelligent monitoring improve operational convenience and system safety, reducing the risk of misoperation.

[0078] In the above embodiment, the process of controlling the operating state of the solenoid valve 62 according to the received pressure signal includes:

[0079] When the first pressure sensor 63 detects that the pressure value of the accumulator 61 is lower than the first set pressure value, the controller controls the solenoid valve 62 to close and start charging the accumulator 61 with liquid.

[0080] When the first pressure sensor 63 detects that the pressure value of the accumulator 61 is higher than the first set pressure value, the controller controls the solenoid valve 62 to de-energize, and the filling ends.

[0081] When the second pressure sensor 64 detects that the pressure value of the accumulator 61 is lower than the second set pressure value, the controller issues an alarm signal.

[0082] It should be noted that when the first pressure sensor 63 detects that the pressure value of the accumulator 61 is lower than the first set pressure value, the controller immediately controls the solenoid valve 62 to close, starting to fill the accumulator 61 with fluid. This instantaneous response ensures that the accumulator 61 can quickly obtain pressurized oil when needed, improving the response speed and reliability of the braking system 5. When the first pressure sensor 63 detects that the pressure value of the accumulator 61 is higher than the first set pressure value, the controller controls the solenoid valve 62 to de-energize, ending the filling process. This precise control avoids unnecessary filling operations, reduces the energy consumption of the hydraulic system, and extends the service life of the accumulator 61. When the second pressure sensor 64 detects that the pressure value of the accumulator 61 is lower than the second set pressure value, the controller issues an alarm signal. This low-pressure alarm function can promptly remind the operator that the pressure of the accumulator 61 is too low, avoiding brake failure due to insufficient pressure and significantly enhancing the safety of the system.

[0083] By ensuring timely filling and preventing overcharging, the accumulator 61 can quickly obtain pressurized oil when needed, while reducing energy consumption of the hydraulic system and extending the service life of the accumulator 61. The low-pressure alarm function promptly alerts operators when the accumulator 61 pressure is too low, preventing brake failure due to insufficient pressure and significantly enhancing system safety. Dynamically adjusting the state of the solenoid valve 62 ensures the hydraulic system operates within the optimal pressure range, improving system adaptability and flexibility while reducing energy consumption. Automated control and intelligent monitoring enhance operational convenience and system safety, reducing the risk of misoperation.

[0084] The forklift's braking operation consists of two steps: fluid filling and braking. Fluid filling is accomplished by the second gear oil pump, the diverter valve 4, and the integrated brake fluid filling valve assembly 6. The diverter valve 4 is located between the second gear oil pump and the multi-way directional valve 3, ensuring a stable flow of oil to the integrated brake fluid filling valve assembly 6. When the first pressure sensor 63 detects that the real-time pressure value of the accumulator 61 is less than the first set pressure value, the solenoid valve 62 inside the integrated brake fluid filling valve assembly 6 is energized, and this signal is transmitted to the controller. The controller then controls the second gear oil pump to start working, filling the accumulator 61 with fluid. Further, when the second pressure sensor 64 detects that the real-time pressure value of the accumulator 61 is less than the second set pressure value (which is less than the first set pressure value), the above fluid filling action is repeated, and an alarm signal is displayed on the forklift's instrument panel. When the first pressure sensor 63 detects that the real-time pressure value of the accumulator 61 is greater than the first set pressure value, the fluid filling ends. When solenoid valve 62 is de-energized, excess oil will flow directly back to oil tank 1 through solenoid valve 62 and the return oil line. Pressure monitoring of accumulator 61 is continuously performed after the forklift is started. When the first pressure sensor 63 detects that the real-time pressure value of accumulator 61 is lower than the first set pressure value, the filling process will begin. The diverter valve 4 ensures a real-time and stable flow supply for the filling process. The service brake is operated by the integrated brake filling valve assembly 6, brake valve 52, and brake 51. When brake valve 52 is depressed, the pressurized oil in accumulator 61 directly enters brake 51, achieving braking. When brake valve 52 is released, the oil inside brake 51 flows directly back to oil tank 1.

[0085] In summary, the electric forklift braking hydraulic system provided by this invention, through the integrated brake filling valve assembly 6 and precise pressure monitoring and control, enables the system to respond rapidly to braking demands, ensuring that the accumulator 61 can obtain pressurized oil instantly when needed, significantly improving braking response speed, reducing braking delay, and enhancing driving safety. The controller automatically controls the operating state of the solenoid valve 62 and brake valve 52 based on real-time pressure signals, ensuring that the braking system 5 can quickly enter the working state when needed, further improving the immediacy and reliability of braking. Through dual monitoring by the first pressure sensor 63 and the second pressure sensor 64, the system can monitor the pressure status of the accumulator 61 in real time, ensuring that the braking system 5 always operates within a safe pressure range. The low-pressure alarm function can promptly remind operators to take measures to avoid brake failure due to insufficient pressure. The integrated brake filling valve assembly 6 and the compact system design reduce the number of connection points and pipelines in the hydraulic system, reducing the risk of leakage and failure, and improving the overall reliability of the system. The controller dynamically adjusts the state of the solenoid valve 62 and brake valve 52 based on real-time pressure signals, ensuring that the hydraulic system maintains optimal performance under different operating conditions. This precise control not only improves braking performance but also reduces energy consumption caused by pressure fluctuations. Through on-demand fluid filling and intelligent energy management, the system avoids unnecessary fluid flow, reducing hydraulic system energy consumption and improving system efficiency. Through automated control and intelligent monitoring, operators no longer need to manually adjust the states of solenoid valve 62 and brake valve 52; the system automatically performs these operations, improving operational convenience and comfort.

[0086] Rapid fluid filling and instant braking significantly improve braking response speed, reduce braking delay, and enhance driving safety. Dual pressure monitoring and a compact system design reduce leakage and failure risks, improving overall system reliability. Precise control and dynamic adjustment ensure optimal performance of the hydraulic system under various operating conditions, reducing energy consumption and improving energy efficiency. Automated control and intelligent monitoring enhance operational convenience and system safety, reduce downtime, and improve equipment operating efficiency. Intelligent monitoring and early warning functions enable comprehensive management and intelligent control of the braking system, improving system intelligence and management efficiency. Reduced maintenance frequency and extended equipment life lower maintenance costs and improve system economy.

[0087] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0088] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0089] The above provides a detailed description of an electric forklift braking hydraulic system and its control method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. A hydraulic braking system for an electric forklift, comprising an oil tank (1), wherein the oil tank (1) is connected to a flow divider valve (4) via an oil supply line, the oil supply line is equipped with a gear pump (2), and the flow divider valve (4) is connected to a braking system (5) via a first branch line, characterized in that, The first branch is equipped with an integrated brake fluid filling valve assembly (6), which includes an accumulator (61) and a solenoid valve (62) connected to the accumulator (61). The solenoid valve (62) is used to control the opening and closing of the first branch. The integrated brake fluid filling valve assembly (6) also includes a pressure monitoring component for real-time monitoring of the pressure value of the accumulator (61). The gear pump (2), the diverter valve (4), the solenoid valve (62) and the pressure monitoring component are all signal connected to the controller.

2. The electric forklift braking hydraulic system according to claim 1, characterized in that, The diverter valve (4) is connected to the multi-way directional valve (3) through the first pipeline, and the multi-way directional valve (3) is connected to the controller signal.

3. The electric forklift braking hydraulic system according to claim 2, characterized in that, The pressure monitoring component includes a first pressure sensor (63) and a second pressure sensor (64). When the first pressure sensor (63) detects that the pressure value of the accumulator (61) is lower than the first set pressure value, the controller controls the solenoid valve (62) to open. When the second pressure sensor (64) detects that the pressure value of the accumulator (61) is lower than the second set pressure value, the controller issues an alarm signal. The second set pressure value is lower than the first set pressure value.

4. The electric forklift braking hydraulic system according to claim 3, characterized in that, The braking system (5) includes a brake (51) and a brake valve (52). The brake valve (52) is used to control the accumulator (61) to supply oil to the brake (51). The brake valve (52) is signal-connected to the controller.

5. The electric forklift braking hydraulic system according to claim 4, characterized in that, A filter (7) is provided on the oil supply pipeline. The filter (7) is located between the oil tank (1) and the gear pump (2). The filter (7) is connected to the controller signal.

6. The electric forklift braking hydraulic system according to claim 5, characterized in that, The integrated brake filling valve assembly (6) and the brake system (5) are connected to the oil tank (1) through the return oil line, and the filter (7) is provided on the return oil line.

7. The electric forklift braking hydraulic system according to claim 6, characterized in that, The oil tank (1) is equipped with an air filter (8) for connecting air, and the air filter (8) is connected to the controller signal.

8. The electric forklift braking hydraulic system according to claim 7, characterized in that, The oil tank (1) is equipped with an oil dipstick (9) for measuring the volume of oil in the oil tank (1).

9. A control method for a hydraulic braking system of an electric forklift, characterized in that, The control method, applied to the electric forklift braking hydraulic system of claim 8, includes: Control the start-up of the gear pump and flow divider valve; The operating status of the solenoid valve is controlled based on the received pressure signal; Open the brake valve to apply the brakes.

10. The control method for the electric forklift braking hydraulic system according to claim 9, characterized in that, The process of controlling the operating state of the solenoid valve based on the received pressure signal includes: When the first pressure sensor detects that the pressure value of the accumulator is lower than the first set pressure value, the controller controls the solenoid valve (62) to close and start filling the accumulator (61) with liquid; When the first pressure sensor (63) detects that the pressure value of the accumulator (61) is higher than the first set pressure value, the controller controls the solenoid valve (62) to de-energize, and the filling ends; When the second pressure sensor detects that the pressure value of the accumulator (61) is lower than the second set pressure value, the controller issues an alarm signal.

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