Electric control system with OPS function and electric control gearbox

Abstract

The invention relates to the technical field of engineering machinery electric control, in particular to an electric control system with an OPS function and an electric control gearbox, and the system is characterized in that a controller is connected with an electric control gear shifting handle, a seat OPS switch and a CutOff power cut-off switch; the controller is connected with the electric control speed change valve group, receives an output signal of the controller and controls a corresponding clutch of the electric control gearbox; the controller is configured to output a gearbox control signal to the electric control speed change valve group based on a signal from the electric control gear shifting handle; in response to a signal from the seat OPS switch, a safety control signal used for enabling the gearbox to return to a neutral gear is output to the electric control speed change valve group; and in response to a signal from the CutOff power cut-off switch, the gearbox control logic output to the electric control speed change valve group during braking is switched. And the safety and the reliability of the system are improved while the operation efficiency is ensured.

Description

Technical Field

[0001] This application relates to the field of electrical control technology for engineering machinery, specifically to an electrical control system with OPS function and an electronically controlled gearbox. Background Technology

[0002] With the rapid development of the logistics industry, large-tonnage forklifts are increasingly used in ports, docks, and factories, placing higher demands on their starting smoothness, shifting stability, and operational safety. Existing forklift transmission systems mostly use mechanical or hydraulic shifting methods, which are insufficient to meet the precise control requirements of the driver's posture sensing system for power operation. This is especially problematic when handling precision equipment or valuable goods, as starting and shifting can cause significant impacts, and the forklift is prone to slippage on inclines, posing significant safety hazards.

[0003] Furthermore, traditional systems lack intelligent judgment and linkage control of the driver's presence, and cannot automatically cut off power and lock the working device when the driver leaves the seat, resulting in higher operational risks. Therefore, there is an urgent need to develop an electronic control system and transmission that integrates intelligent sensing, electronic shifting, and multiple safety protection functions to improve the smoothness, adaptability, and inherent safety level of the vehicle operation. Summary of the Invention

[0004] To address the above problems, the present invention provides an electronic control system with OPS function and an electronically controlled transmission.

[0005] In a first aspect, the present invention provides an electronic control system with OPS function, applied to an electronically controlled transmission, the system including a controller, an electronically controlled shift lever, a seat OPS switch, a CutOff power cut-off switch and an electronically controlled transmission valve group; The controller's input port is connected to the electronic gear shift lever, the seat OPS switch, and the CutOff power cut-off switch; The controller's output port is connected to the electronically controlled transmission valve group, receives the controller's output signal, and controls the corresponding clutch of the electronically controlled transmission. The controller is configured to: Based on the signal from the electronically controlled shift lever, a transmission control signal is output to the electronically controlled transmission valve group through the output port; In response to a signal from the seat OPS switch, a safety control signal for returning the transmission to neutral is output to the electronically controlled transmission valve group through the output port; In response to a signal from the CutOff power cut-off switch, the transmission control logic output to the electronically controlled transmission valve group through the output port is switched during braking.

[0006] By coordinating the signal interaction between the electronic shift lever, seat OPS switch, CutOff power cut-off switch and electronic transmission valve group through the controller, signal delay or conflict caused by the decentralized control of multiple components is avoided, wiring harness connections are reduced, system failure rate is lowered, and the integration and reliability of the electronic control system of heavy-duty forklifts and other equipment are improved.

[0007] Targeting three core operating scenarios—gear control, driver presence protection, and braking power adaptation—the controller's differentiated signal output logic enables precise control of regular gear shifting, mitigates the risk of accidental vehicle movement after the driver leaves the seat through the OPS function, and adapts to different braking conditions with the CutOff function, comprehensively meeting the stringent safety requirements of construction machinery.

[0008] The control logic is designed around the clutch drive requirements of the electronically controlled transmission, which can be adapted to electronically controlled transmissions of different tonnages and transmission parameters without major modifications to the transmission itself, thus reducing the cost of equipment upgrades and modifications.

[0009] As a preferred embodiment of the technical solution of the present invention, the seat OPS switch is a normally open switch; When the driver sits down, the seat OPS switch closes, inputting a first status signal to the controller; when the driver leaves, the seat OPS switch opens, inputting a second status signal to the controller. The controller is configured to periodically scan the signal of the seat OPS switch at a settable scan period T; and when the second state signal is scanned and the state continues for more than a first preset time threshold t, output the safety control signal. The scanning period T and the first preset time threshold t are both parameterized by the controller.

[0010] By using a dual judgment logic of preset time threshold t and periodic scanning, the system effectively filters out the seat OPS switch erroneously disconnected signal caused by road bumps or the driver's brief adjustment of sitting posture, preventing the system from erroneously outputting a return to neutral command, ensuring the stability of continuous operation scenarios such as shoveling and transporting precision and valuable items, and reducing the number of operation interruptions.

[0011] The scanning period T and time threshold t can be customized by the controller. For example, in a port dock with severe turbulence, T can be increased to reduce scanning sensitivity, while in a precision instrument handling scenario, t can be decreased to improve safety response speed. This allows the system to flexibly optimize control strategies according to the actual working environment and enhance adaptability.

[0012] As a preferred embodiment of the present invention, the controller is further configured to: after outputting the safety control signal, when the signal of the seat OPS switch is restored from the second state signal to the first state signal, maintain the gear lock of the electronically controlled transmission; only when a signal is subsequently received that the electronically controlled shift lever has returned to the neutral position, the lock is released and normal control logic is restored.

[0013] After the driver returns to the seat, the system maintains the transmission locked state. The lock can only be released by actively returning the lever to neutral. This prevents sudden lurching of the vehicle caused by the driver not returning to neutral before leaving the seat and then immediately resuming power upon returning. This is particularly suitable for starting safety control of heavy forklifts transporting heavy materials, reducing the risk of collisions or material tipping. Using neutral as a prerequisite for unlocking aligns with the standard operating procedure for construction machinery drivers (confirming the gear is neutral before starting), requiring no additional training and reducing errors due to unfamiliarity with the operating logic, thus improving the user-friendliness and safety of the human-machine interface.

[0014] As a preferred embodiment of the present invention, the controller is further configured to perform neutral start protection, that is, only when the electronically controlled shift lever is in the neutral position is the engine start permission signal allowed to be output through the output port.

[0015] It only allows the output of the engine start permission signal when the electronic shift lever is in neutral, completely eliminating engine stalling, transmission shock or sudden vehicle movement caused by starting in gear, protecting core components such as the engine and transmission from damage, and avoiding safety threats to operators due to starting in gear. It is especially suitable for the starting safety requirements of heavy-duty equipment such as large-tonnage forklifts.

[0016] Without relying on the driver's subjective judgment, the controller's forced logic enables start-up protection, reducing safety accidents caused by operator negligence and lowering safety management costs during equipment use.

[0017] As a preferred embodiment of the technical solution of the present invention, the controller is configured as follows: When the CutOff power cut-off switch indicates that the function is enabled, if a braking signal is detected, the electronically controlled transmission will be controlled to return to neutral through the electronically controlled transmission valve group to achieve power cut-off. When the CutOff power cut-off switch indicates that the function is off, even if a braking signal is detected, the current gear of the electronically controlled transmission is maintained through the electronically controlled transmission valve group to keep the power uninterrupted. The operation of returning to neutral during braking is only performed when the CutOff function is activated and the electronically controlled transmission is in a low gear of first or second gear.

[0018] The CutOff function is distinguished between on and off modes, enabling rapid power cut-off during braking on flat ground and power retention during hill starts. It also limits braking to neutral only when the gear is low, avoiding transmission shock caused by sudden power cut-off during high-gear braking and extending the service life of the transmission.

[0019] Drivers do not need to manually adjust the power cut-off logic according to working conditions; they can simply switch modes using the CutOff switch. This is especially beneficial in work scenarios where there is frequent switching between slopes and flat ground, reducing operational steps, lowering driver fatigue, and indirectly improving work safety.

[0020] As a preferred embodiment of the technical solution of the present invention, the system further includes an OPS working device switch, which is connected to the input port of the controller; The controller is configured to: When both the seat OPS switch and the OPS working device switch are simultaneously received, indicating that the driver is in position, a first control signal is output to allow the hydraulic system of the working device to operate normally. If signals indicating the driver's presence are not received simultaneously, a second control signal is output to lock the hydraulic system of the working device.

[0021] The OPS function is extended from gearbox control to working device hydraulic system control. Through the dual confirmation logic of dual switches (seat OPS and working device OPS), it is ensured that the hydraulic system is only allowed to work when the driver is in the seat and the working device is in a safe state. This prevents displacement of the gantry, forks and other working devices due to hydraulic leakage or accidental triggering after the driver leaves the seat, thus protecting the safety of surrounding equipment and personnel.

[0022] The locking / unlocking logic of the working device is linked with the OPS control logic of the transmission to form an integrated safety control system for vehicle power and working device operation, avoiding safety vulnerabilities caused by asynchronous control between the two and further improving the overall safety of the equipment.

[0023] As a preferred embodiment of the present invention, the controller locks and unlocks the hydraulic system of the working device by controlling the opening and closing of an electrically controlled switch valve located in the hydraulic system circuit of the working device.

[0024] Locking of the working device is achieved by controlling the on / off state of an electrically controlled switching valve in the hydraulic circuit. Compared to mechanical locking structures, this method offers a faster response time and avoids locking failure due to mechanical wear. It is particularly suitable for high-frequency operation scenarios, ensuring the stability and durability of the working device's locking mechanism. The electrically controlled switching valve is highly integrated and compact, allowing it to be directly integrated into the hydraulic circuit of the working device without the need for additional complex locking mechanisms, thus reducing equipment manufacturing costs. Furthermore, troubleshooting and replacement of the switching valve are convenient, reducing subsequent maintenance time and costs.

[0025] Secondly, the present invention provides an electronically controlled transmission, comprising: The gearbox body contains multiple clutches; The electronic control system as described in the first aspect; the electronically controlled transmission valve group in the electronic control system is integrated on the gearbox body, including multiple electronically proportional valves that are connected one-to-one with the clutches.

[0026] By directly integrating the electronically controlled transmission valve assembly into the transmission body, the distance between the hydraulic oil passages of the electronic proportional valve and the clutch is shortened, reducing hydraulic oil flow resistance and pressure loss, improving the clutch engagement / disengagement response speed, and avoiding the risk of oil leakage caused by decentralized installation, thus ensuring the transmission efficiency of the transmission.

[0027] Equipped with the electronic control system described in the first aspect, the clutch control of the transmission is deeply integrated with safety functions such as OPS and CutOff, further improving the safety control precision and reliability of the transmission.

[0028] By controlling multiple electro-proportional valves and clutches in a one-to-one correspondence, precise switching of multiple gears can be achieved, meeting the speed and traction requirements of large-tonnage forklifts in different operating scenarios and improving equipment operating efficiency.

[0029] As a preferred embodiment of the technical solution of the present invention, the multiple clutches include a forward clutch and a reverse clutch for controlling the forward and reverse directions, and a first-gear clutch, a second-gear clutch, a third-gear clutch and a fourth-gear clutch for controlling specific gear positions. The electronically controlled transmission valve group includes a forward proportional valve, a reverse proportional valve, a first gear proportional valve, a second gear proportional valve, a third gear proportional valve, and a fourth gear proportional valve, each corresponding to one of the clutches. The controller is configured to: when the seat OPS switch indicates that the driver has been away from the seat for more than a set time, control the forward proportional valve and / or the reverse proportional valve to disengage the forward clutch and / or the reverse clutch, thereby returning the transmission to neutral. The controller is also configured to: respond to the signal of the CutOff power cut-off switch, switch the control logic of the electronically controlled transmission valve group during braking to achieve power cut-off on flat ground or power holding on slopes; and control the hydraulic pressure build-up process of the corresponding clutch by outputting a specific PWM current curve to the electro-proportional valve to achieve smooth engagement.

[0030] When the driver leaves the seat, only the forward / reverse clutch is disengaged, without having to disengage all gear clutches. This achieves the safe goal of returning the transmission to neutral while avoiding wear caused by frequent disengagement / engagement of other gear clutches, extending clutch life, and shortening the response time to return to neutral.

[0031] By controlling the hydraulic output of the electro-proportional valve through a specific PWM current curve, linear adjustment of the clutch pressure build-up process is achieved, avoiding the sudden rise and fall of pressure caused by traditional on / off valve control, reducing shift shock and noise, and improving driving comfort. It is especially suitable for scenarios with high requirements for stability, such as shoveling and transporting precision instruments and fragile items.

[0032] The control logic of the valve group is switched in response to the CutOff signal, so that the gearbox can quickly return to neutral when braking on flat ground and maintain power when braking on a slope. This adapts to the operation needs of large-tonnage forklifts in complex terrains such as ports and factories, and broadens the applicable scenarios of the equipment.

[0033] As a preferred embodiment of the technical solution of the present invention, the electronically controlled gear shift lever integrates gear shifting and reversing functions; wherein, reversing is achieved by pushing the lever forward or pulling it back to switch between three positions: forward, neutral, and reverse; gear shifting is achieved by rotating the lever to switch between four positions: first gear, second gear, third gear, and fourth gear. The electronically controlled gear shift lever is equipped with a locking button. When the locking button is in the locked state, the gear shifting operation of the electronically controlled gear shift lever is mechanically locked.

[0034] By integrating the forward / rear shifting and rotary shifting designs, the functions of two traditional levers are combined into a single lever, reducing driver actions and operational complexity. It is especially suitable for high-frequency shifting and reversing scenarios, thereby improving operational efficiency.

[0035] When the locking button is in the locked state, the gear shifting operation is mechanically locked to prevent the handle from being accidentally rotated due to bumps or collisions during vehicle operation. This prevents transmission system shocks or sudden changes in vehicle speed caused by accidental gear shifting and also prevents unauthorized personnel from accidentally activating the handle, further improving the safety of equipment operation.

[0036] The lever's directional (forward / neutral / reverse) and gear shifting (first to fourth gear) positions are clearly defined, and the operation is ensured by physical constraints (such as gear position stops), reducing the risk of misoperation caused by driver error in gear judgment, and is especially suitable for novice operators to quickly get started.

[0037] As can be seen from the above technical solutions, this application has the following advantages: by integrating the controller, electronic shift lever, seat OPS switch, CutOff power cut-off switch and electronic transmission valve group into one system, unified management and intelligent decision-making of the whole machine control are realized, and the reliability and response speed of the system are improved.

[0038] The OPS function employs a dual protection mechanism (seat switch + working device switch) to automatically cut off power and lock the working device when the driver leaves the seat, effectively preventing accidents caused by misoperation. The CutOff function offers two working modes: flat ground and ramp. By intelligently recognizing working conditions, it automatically switches the power cut-off logic, ensuring both braking efficiency on flat ground and safety when starting on ramps. Through parameterized scanning cycles and time thresholds, combined with precise control of the PWM current curve, it achieves flexible adjustment of the clutch engagement process, greatly improving shift smoothness and operating comfort.

[0039] The neutral start protection and handle locking device form multiple safety protections, effectively avoiding the risks of accidental start and misoperation. Attached Figure Description

[0040] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A connection block diagram of the system provided in an embodiment of the present invention.

[0042] Figure 2 This is a control logic diagram in an embodiment of the present invention.

[0043] Figure 3 This is a diagram illustrating the controller connection in an embodiment of the present invention. Detailed Implementation

[0044] To make the purpose, features, and advantages of this application more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solution protected by this application. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0046] like Figure 1 and Figure 2As shown, this embodiment of the invention provides an electronic control system with OPS function, applied to an electronically controlled transmission. The system includes a controller, an electronically controlled shift lever, a seat OPS switch, a CutOff power cut-off switch, and an electronically controlled transmission valve group. The controller's input port is connected to the electronic gear shift lever, the seat OPS switch, and the CutOff power cut-off switch; The controller's output port is connected to the electronically controlled transmission valve group, receives the controller's output signal, and controls the corresponding clutch of the electronically controlled transmission. The controller is configured to: Based on the signal from the electronically controlled shift lever, a transmission control signal is output to the electronically controlled transmission valve group through the output port; In response to a signal from the seat OPS switch, a safety control signal for returning the transmission to neutral is output to the electronically controlled transmission valve group through the output port; In response to a signal from the CutOff power cut-off switch, the transmission control logic output to the electronically controlled transmission valve group through the output port is switched during braking.

[0047] The gearbox is a core transmission component of construction machinery, earthmoving machinery, and other engineering vehicles. Its main functions are shifting gears and changing direction to meet the vehicle's traction and speed requirements. Based on the shifting method, it can be divided into mechanical shifting, hydraulic shifting, and electronic shifting, with electronic shifting technology becoming increasingly widespread. The electronic control system is the gearbox's operating system. The driver manipulates the shift lever to change direction and gears; typically, shifting direction is achieved by moving the lever forward or backward, and gear shifting is achieved by rotating the lever. The controller is a major component of the electronic control system of the gearbox. Its main function is to store and execute electronic control programs. The controller takes input signals and, by executing the electronic control programs, outputs signals from the output ports. This improves the smoothness of clutch engagement, ensuring a smooth start and good safety when the forklift is transporting valuable goods.

[0048] The electronic control system is equipped with an OPS (Optical Power Switch) module, primarily used to control the transmission's electronic valves and the working device. To ensure safe operation, the vehicle can only move normally and the working device can only function properly when the driver is in the seat. Conversely, when the driver is out of the seat, the OPS switch is in the off state, serving as an input signal to the controller. The electronic control module processes this signal, and the controller outputs a signal to control the electronic valves, returning the vehicle to neutral and locking the hydraulic system of the working device, thus ensuring the vehicle remains stationary.

[0049] The OPS (Optical Performance System) module includes a function to determine the driver's intentions. The time the driver leaves the seat is parameterized, typically set to 3 seconds. This is primarily to account for misjudgments caused by factors such as road surface roughness. The OPS function is only effective when the driver has been away from the seat for more than the set time.

[0050] The electronic control system includes a CutOff switch with two operating modes. Drivers can select the mode according to different operating conditions. When starting on an incline, the CutOff switch is activated, ensuring uninterrupted power when braking, thus preventing the vehicle from sliding and improving safety. When driving on level ground, the CutOff switch is deactivated; when braking, the transmission automatically shifts to neutral, interrupting power and allowing for rapid braking.

[0051] The electronic control system provided by this invention is equipped with OPS and CutOff functions. Its main purpose is to meet the requirements for stability and operational safety when transporting precision equipment, machine tools, and other valuable items using large-tonnage forklifts, thereby improving the driving experience and safety of the vehicle.

[0052] This application is based on the operating scenario of a large-tonnage forklift (compatible with a 4-speed front and 3-speed rear fixed-shaft power shift transmission), and combines the core components of the electronic control system (controller, electronic shift lever, seat OPS switch, CutOff power cut-off switch, electronic transmission valve group, etc., such as...) Figure 3 The collaborative working logic is shown in the figure.

[0053] After the controller (including input ports, output ports, processor and storage device) is connected to the vehicle power supply through the wiring harness, the control program is downloaded to the storage device via the data communication line. The processor completes initialization and detects the communication status of each component. If the electronic shift lever (integrating shift and reversing functions), seat OPS switch, CutOff power cut-off switch and electronic transmission valve group are all communicating normally, the system enters standby mode.

[0054] The driver must shift the electronic gear shift lever to the neutral (N) position (the middle position of the lever). Only after the controller input port detects the neutral signal will it output a start permission signal to the engine ECU through the output port. If the lever is in the forward (F) position, reverse (R) position, or any gear position (rotated to the 1st-4th gear position), the controller will not output the start permission signal, thus realizing neutral start protection.

[0055] After the engine is started, the driver unlocks the electronic shift lever by pressing the locking button (releasing the mechanical lock), and then operates the lever according to the work requirements: Reversing control: Push the handle forward to the F position, and the controller receives a forward signal; push the handle backward to the R position, and it receives a reverse signal. Gear shifting control: Rotate the handle to the corresponding position of gear 1-4 (the handle base shell is marked with gear position markings, and the arrow on the rotating part points to the target gear), and the controller receives the gear position signal; Based on the reversing and gear combination signals, the controller outputs a specific PWM current signal to the corresponding proportional valve of the electronically controlled transmission valve group through the output port. For example, when moving forward to first gear, the controller outputs a PWM signal to the KV forward proportional valve (corresponding to the KV forward clutch) and the K1 proportional valve (corresponding to the K1 gear clutch) to control the two clutches to gradually engage (while the other clutches disengage), thus achieving smooth power transmission. The PWM current curve is parameterized and optimized, and through three stages of control—oil filling and pressure building, engagement, and clamping—it ensures smooth clutch engagement and avoids shift shock.

[0056] Oil filling stage (0~T1): The current duty cycle slowly increases from 0% to 30% to ensure that the hydraulic oil smoothly fills the clutch oil chamber and avoids oil shock; Engagement phase (T1~T2): The current duty cycle increases linearly from 30% to 70%, the clutch friction plates gradually contact, and a soft power connection is achieved; Clamping stage (T2~T3): The current duty cycle increases from 70% to 90%, the clutch is fully engaged, and power is transmitted stably; The three time periods are dynamically allocated according to the target pressure build-up time, ultimately achieving shock-free clutch engagement and meeting the stability requirements when transporting precision and valuable items.

[0057] In some embodiments, the seat OPS switch is a normally open switch; When the driver sits down, the seat OPS switch closes, inputting a first status signal to the controller; when the driver leaves, the seat OPS switch opens, inputting a second status signal to the controller. The controller is configured to periodically scan the signal of the seat OPS switch at a settable scan period T; and when the second state signal is scanned and the state continues for more than a first preset time threshold t, output the safety control signal. The scanning period T and the first preset time threshold t are both parameterized by the controller.

[0058] The controller is also configured to: after outputting the safety control signal, maintain gear lock on the electronically controlled transmission when the signal of the seat OPS switch changes from the second state signal to the first state signal; and only unlock and restore normal control logic when a signal is subsequently received that the electronically controlled shift lever has returned to the neutral position.

[0059] The controller is also configured to perform neutral start protection, that is, to allow the output of an engine start permission signal through the output port only when a signal is received that the electronically controlled shift lever is in the neutral position.

[0060] The seat OPS switch is triggered by gravity to close after the driver sits down, inputting a high-level signal (first state signal) to the controller; at the same time, the OPS working device switch on the working device detects the driver's operating intention and inputs an in-position signal to the controller. After receiving both signals at the same time, the controller input port outputs a first control signal (valve closure) to the electronically controlled switch valve of the working device hydraulic system through the output port, allowing the working device such as the gantry to operate normally (such as fork lifting).

[0061] If the driver temporarily leaves the seat (e.g., to adjust cargo), the seat OPS switch disconnects and sends a low-level signal (second status signal) to the controller. The controller periodically collects this signal at a settable scan period T (set via host computer software). If the duration of the low-level signal is less than or equal to the preset time threshold t (default 3s, supports debugging and modification), it is determined to be a false trigger such as road bumps. The controller maintains the current PWM signal of the electronically controlled transmission valve group, the gearbox maintains the original gear, and the hydraulic system of the working device works normally. If the duration of the low-level signal is greater than t, the controller determines that the device is effectively disengaged and immediately executes dual safety controls: ① Outputs a safety control signal to the electronically controlled transmission valve group, cuts off the PWM signal of the KV forward proportional valve or the KR reverse proportional valve (according to the current reversing state), disengages the clutch in the corresponding direction, and returns the transmission to neutral; ② Cuts off the control signal of the electronically controlled switch valve of the hydraulic system of the working device (outputs a second control signal), disconnects the valve, suspends the hydraulic system, and locks the working device (e.g., the gantry cannot move).

[0062] After the driver returns to the seat, the seat OPS switch closes again (the signal changes from low level to high level), but the controller still maintains the transmission neutral lock state. Only when the driver operates the electronic shift lever to rotate to the neutral (N) position (the controller detects the neutral signal) and then shifts to the target gear, will the controller release the lock and resume outputting the PWM signal to the corresponding proportional valve, allowing the transmission to work normally.

[0063] After the driver returns to the seat, the seat OPS switch closes again, sending a high-level signal to the controller, but the controller remains locked. The driver needs to manually shift the electronic gear shift lever to the neutral (N) position. Only after the controller detects the neutral reset signal will the gearbox and the working device be unlocked. After unlocking, the driver can switch between F / R directional and 1-4 gear shifting as needed, and the transmission can then work normally, avoiding the safety risks caused by the driver directly shifting gears after returning.

[0064] In some embodiments, the controller is configured to: When the CutOff power cut-off switch indicates that the function is enabled, if a braking signal is detected, the electronically controlled transmission will be controlled to return to neutral through the electronically controlled transmission valve group to achieve power cut-off. When the CutOff power cut-off switch indicates that the function is off, even if a braking signal is detected, the current gear of the electronically controlled transmission is maintained through the electronically controlled transmission valve group to keep the power uninterrupted. The operation of returning to neutral during braking is only performed when the CutOff function is activated and the electronically controlled transmission is in a low gear of first or second gear.

[0065] The controller switches the control logic for the electronic transmission valve group during braking based on the mode signal from the CutOff power cut-off switch (received at the input port), adapting to both flat ground and incline driving conditions. Flat Ground Mode (CutOff Function Activated): When the driver turns on the CutOff switch, the controller detects this signal. If the vehicle is in first or second gear (low gear) and the driver presses the brake pedal (the controller input port receives the service brake signal), it immediately cuts off the PWM signals of all proportional valves in the electronically controlled transmission valve group through the output port, controlling the transmission to return to neutral, achieving rapid power cut-off and shortening the braking distance. If the vehicle is in third or fourth gear (high gear), even if a braking signal is detected, the controller maintains the current gear PWM signal to avoid transmission shock caused by sudden power cut-off in high gear.

[0066] Hill Start Mode (CutOff Function Off): When starting or driving on a hill (such as shoveling delicate and valuable items uphill), the driver sets the CutOff switch to the off state. At this time, even if the brake pedal is pressed, the controller maintains the PWM signal of the current gear of the electronic transmission valve group. For example, when driving on a hill in forward 2nd gear, it continuously outputs signals to the KV forward proportional valve and the K2 proportional valve to keep the two clutches engaged, avoid power interruption causing the vehicle to roll downhill, and ensure the safety of hill operation.

[0067] In some embodiments, the system further includes an OPS operating device switch connected to the input port of the controller; The controller is configured to: When both the seat OPS switch and the OPS working device switch are simultaneously received, indicating that the driver is in position, a first control signal is output to allow the hydraulic system of the working device to operate normally. If signals indicating the driver's presence are not received simultaneously, a second control signal is output to lock the hydraulic system of the working device.

[0068] The controller locks and unlocks the hydraulic system of the working device by controlling the opening and closing of an electrically controlled switch valve located in the hydraulic system circuit of the working device.

[0069] The controller connects to the pressure sensors at the clutch pressure test ports of each gear through the input port to collect the clutch working pressure in real time (normal range 0.8-1.2MPa). If the pressure exceeds the range, the controller outputs a pressure alarm signal to the vehicle's instrument panel through the output port, triggering the pressure alarm light. At the same time, when reversing, the controller detects the reverse R signal and automatically outputs a reversing alarm control signal to improve the surrounding safety warning effect.

[0070] After the vehicle stops operating, the driver pulls up the parking brake lever. The controller input port receives the parking brake signal and controls the normally open drum parking brake at the output end of the gearbox to lock through the output port, thus achieving safe braking. When starting again, after releasing the parking brake, the controller resumes control of the electronic transmission valve group, allowing the clutch to engage.

[0071] If the controller detects an abnormal seat OPS switch signal (such as a continuous high level but no driver operation), a faulty electro-proportional valve (no feedback of PWM signal), or a sudden drop in hydraulic pressure, it will immediately execute emergency protection—cut off all clutch PWM signals, force the transmission to return to neutral, lock the hydraulic system of the working device, and output a fault code to the instrument through the vehicle communication module to facilitate troubleshooting by maintenance personnel.

[0072] After the system is powered on, the controller first performs a self-test and establishes communication with the vehicle system via the CAN bus. The controller detects the current position of the electronic gear shift lever; if it is not in neutral (N), it prompts the driver to return the lever to neutral via the instrument panel. Simultaneously, the controller continuously monitors the status of the seat OPS switch. Only when it confirms that the driver is in position and the lever is in neutral will it output a start permission signal to the engine control system, completing system initialization. This neutral start protection mechanism effectively prevents potential safety hazards that may arise from starting the vehicle in gear.

[0073] The driver selects the gear according to the operational requirements using the electronically controlled gear shift lever. Taking first gear as an example, the driver first pushes the reversing lever forward to the forward (F) position, and then rotates the gear shift lever to the first gear position. After receiving the lever signal, the controller outputs specific PWM current signals to the KV proportional valve and K1 proportional valve of the electronically controlled transmission valve group through its built-in control algorithm. Under the control of the PWM signal, these two proportional valves precisely adjust the hydraulic oil pressure, so that the KV forward clutch and K1 first gear clutch are smoothly engaged, while the other clutches remain disengaged, realizing the power output of first gear.

[0074] During vehicle operation, the controller continuously scans the status of the seat OPS switch every 100ms. When the driver leaves the seat for any reason, the OPS switch changes from closed to open. To prevent misjudgment due to vehicle vibrations, the controller has a 3-second delay mechanism. Only if the driver remains off-seat for more than 3 seconds will the controller execute safety controls: immediately cutting off the output signal to the KV and KR proportional valves, disengaging the steering clutch, and shifting the transmission to neutral; simultaneously cutting off the control valve signal of the hydraulic system of the working device, locking the working device. This dual safety protection ensures that the vehicle automatically enters a safe state when the driver leaves the seat.

[0075] When the driver returns to the seat and the OPS switch closes again, the system does not immediately restore power. The controller remains in a safety locked state until the driver actively moves the gear shift lever to the neutral position, at which point the system is unlocked. This "neutral-to-unlock" design avoids the risk of the vehicle suddenly moving due to the driver accidentally sitting down, further enhancing the system's safety.

[0076] The system offers selectable power cut-off modes for different operating conditions. When operating on flat surfaces, the driver activates the CutOff function. When the vehicle is in a low gear and the brakes are applied, the controller immediately returns the transmission to neutral, achieving rapid power cut-off and improving braking efficiency. On slopes, the driver deactivates the CutOff function. Even when the brakes are applied, the controller maintains the clutch engagement in the current gear, ensuring uninterrupted power and effectively preventing the vehicle from slipping.

[0077] To achieve a smooth shifting experience, the system employs an intelligent clutch control strategy. The controller internally stores multiple optimized PWM current curves, compensating and correcting control parameters based on real-time transmission fluid temperature monitoring during shifts. Precise control of the clutch's hydraulic pressure build-up process via an electro-proportional valve enables smooth clutch engagement, significantly improving shift smoothness and operational comfort.

[0078] The system is also equipped with multiple auxiliary safety functions: the electronically controlled gear shift lever has a mechanical locking button to prevent accidental operation; the working device has an independent OPS detection switch, which, together with the seat switch, forms a dual-path detection system; and the transmission output is equipped with a parking brake, which is linked to the OPS function for control. These measures together construct a comprehensive safety protection system.

[0079] This invention provides an electronically controlled transmission, comprising: The gearbox body contains multiple clutches; The electronic control system described in the above embodiments; the electronically controlled transmission valve group in the electronic control system is integrated on the gearbox body, including multiple electronically proportional valves that are connected one-to-one with the clutches.

[0080] Multiple clutches include a forward clutch and a reverse clutch for controlling forward and reverse directions, and a first-gear clutch, a second-gear clutch, a third-gear clutch and a fourth-gear clutch for controlling specific gear positions; The electronically controlled transmission valve group includes a forward proportional valve, a reverse proportional valve, a first gear proportional valve, a second gear proportional valve, a third gear proportional valve, and a fourth gear proportional valve, each corresponding to one of the clutches. The controller is configured to: when the seat OPS switch indicates that the driver has been away from the seat for more than a set time, control the forward proportional valve and / or the reverse proportional valve to disengage the forward clutch and / or the reverse clutch, thereby returning the transmission to neutral. The controller is also configured to: respond to the signal of the CutOff power cut-off switch, switch the control logic of the electronically controlled transmission valve group during braking to achieve power cut-off on flat ground or power holding on slopes; and control the hydraulic pressure build-up process of the corresponding clutch by outputting a specific PWM current curve to the electro-proportional valve to achieve smooth engagement.

[0081] The electronically controlled gear shift lever integrates gear shifting and reversing functions; reversing is achieved by pushing the lever forward or pulling it back to switch between three positions: forward, neutral, and reverse; gear shifting is achieved by rotating the lever to switch between four positions: first gear, second gear, third gear, and fourth gear. The electronically controlled gear shift lever is equipped with a locking button. When the locking button is in the locked state, the gear shifting operation of the electronically controlled gear shift lever is mechanically locked.

[0082] As the core actuator for power transmission in a gearbox, the smoothness of clutch engagement directly affects the stability of forklift starting and shifting. This application achieves precise control through a triple strategy of oil temperature correction, speed matching, and PWM curve control. The specific steps are as follows: When the driver operates the electronically controlled gear shift lever (integrated shifting / reversing function) to change gears, the controller first obtains the actual oil temperature (range -20℃~120℃) through the temperature sensor built into the transmission, and corrects the target pressure build-up time according to the preset oil temperature-pressure build-up time mapping table. For example, when the oil temperature is 20℃, the target pressure build-up time is 0.8s. For every 10℃ increase in oil temperature, the pressure build-up time is shortened by 0.1s (to avoid too fast engagement caused by the decrease in oil viscosity at high temperatures), and for every 10℃ decrease in oil temperature, the pressure build-up time is extended by 0.15s (to avoid delayed engagement caused by the increase in oil viscosity at low temperatures).

[0083] The controller simultaneously collects the input speed (linked to engine speed) and output speed (linked to wheel speed) of the clutch corresponding to the target gear in real time via a speed sensor, and calculates the speed difference between the two: If the speed difference is greater than the preset threshold (normally set to 50r / min), the controller adjusts the shift motor to work in torque mode, and quickly reduces the speed difference by increasing the torque. When the speed difference is less than or equal to the preset threshold, the shift motor is immediately switched from torque mode to speed mode to avoid clutch shock caused by excessive torque. At the same time, the controller combines the corrected target pressure build-up time with the current oil temperature to generate the current-engagement time correspondence of the shift control valve (i.e., the electro-proportional valve), providing a basis for subsequent PWM signal output.

[0084] As a core component of human-machine interaction, the electronically controlled gear shift lever integrates gear shifting, steering, and safety locking functions. Its operation process and safety protection logic are as follows: Handlebar functions and operation: Reversing operation: The lever has three positions: forward (F), neutral (N), and reverse (R). The driver can switch directions by pushing forward or reversing backward. The middle position (N) is neutral by default. Gear shifting operation: The handle has a rotatable gear ring, and the base shell is marked with gear 1, 2, 3, and 4. When the arrow on the rotating ring points to the target gear, the gear shift from 1 to 4 is completed. Safety Lock: A locking button is located on the top of the handle. When pressed, the mechanical locking pin locks the rotating ring, preventing gear shifting (to prevent accidental activation). To unlock, simply press the button again to release the lock.

[0085] Neutral start protection activated: Before starting the forklift, the controller will detect the position of the electronic shift lever. Only when the lever is in the neutral (N) position, the controller input port receives a neutral signal and then outputs a start permission signal to the engine ECU through the output port, allowing the engine to start normally; If the lever is in the F / R position or the 1-4 gear shift position, the controller will not output a start permission. Even if the key is inserted and turned to the start position, the engine will not start, thus preventing the vehicle from jerking or the engine from stalling due to starting in gear.

[0086] The OPS (Operating System) function achieves safety control of the vehicle and working equipment through driver presence detection, delay determination, and dual locking. The specific logic is as follows: The seat OPS switch is a normally open micro switch, installed under the driver's seat cushion, and closed by the driver's weight. When the driver sits down, the switch closes, inputting a high-level presence signal to the controller; When the driver leaves the seat, the switch is turned off, and a low-level departure signal is input to the controller; Meanwhile, the working device (such as the gantry) is equipped with an OPS working device switch, which forms a dual detection system with the seat OPS switch.

[0087] The controller acquires the seat OPS switch signal in real time with a period of 0.2 seconds. If the low-level seat-off signal lasts for ≤3s (preset threshold t, which can be adjusted), it is determined to be due to road bumps or a brief seat-off (such as reaching for an object). The controller maintains the current control state, the gearbox maintains the original gear, and the working device works normally. If the low-level off-seat signal lasts for more than 3 seconds, it is determined to be a valid off-seat signal, and the controller immediately performs dual protection: ① Outputs a signal to the electronically controlled transmission valve group to cut off the current of the forward / reverse proportional valve, the corresponding clutch disengages, and the gearbox automatically returns to neutral; ② Cuts off the current of the electronically controlled switch valve of the hydraulic system of the working device, the hydraulic circuit is unloaded, and the gantry and other working devices are locked and cannot be moved.

[0088] After the driver returns to the seat, the seat OPS switch closes again, sending a high-level signal to the controller, but the controller remains locked. The driver needs to manually shift the electronic gear shift lever to the neutral (N) position. Only after the controller detects the neutral reset signal will the gearbox and the working device be unlocked. After unlocking, the driver can switch between F / R directional and 1-4 gear shifting as needed, and the transmission can then work normally, avoiding the safety risks caused by the driver directly shifting gears after returning.

[0089] The CutOff function adapts to both flat ground and sloped terrain operating conditions through mode switching, ensuring driving safety in different scenarios. The specific control logic is as follows: Function switches and mode definitions: The cab control panel is equipped with a CutOff power cut-off switch, which has two positions: on and off. Activation mode: Adapted for flat ground driving conditions; Off mode: Adapts to hill start / driving conditions (slope ≥ 15°).

[0090] Flat Ground Mode (CutOff Activated): When the driver presses the brake pedal, the controller detects the braking signal. If the transmission is in 1 / 2 low gear, it immediately controls the electronic transmission valve group to cut off the current of all proportional valves, and the transmission automatically returns to neutral, interrupting power and achieving rapid braking. If it is in 3 / 4 high gear, it maintains the current gear (to avoid braking shock in high gear). Ramp mode (CutOff off): Even if the driver presses the brake pedal, the controller maintains the proportional valve current corresponding to the current gear, the gearbox keeps the original gear, the power is not interrupted, and the forklift is prevented from rolling on the ramp (especially suitable for starting on a ramp when transporting precision and valuable items, to avoid the goods tilting and being damaged).

[0091] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An electronic control system with OPS function, applied to an electronically controlled transmission, characterized in that, The system includes a controller, an electronically controlled gear shift lever, a seat OPS switch, a CutOff power cut-off switch, and an electronically controlled transmission valve assembly. The controller's input port is connected to the electronic gear shift lever, the seat OPS switch, and the CutOff power cut-off switch; The controller's output port is connected to the electronically controlled transmission valve group, receives the controller's output signal, and controls the corresponding clutch of the electronically controlled transmission. The controller is configured to: Based on the signal from the electronically controlled shift lever, a transmission control signal is output to the electronically controlled transmission valve group through the output port; In response to a signal from the seat OPS switch, a safety control signal for returning the transmission to neutral is output to the electronically controlled transmission valve group through the output port; In response to a signal from the CutOff power cut-off switch, the transmission control logic output to the electronically controlled transmission valve group through the output port is switched during braking.

2. The electronic control system with OPS function according to claim 1, characterized in that, The seat OPS switch is a normally open switch; When the driver sits down, the seat OPS switch closes, inputting a first status signal to the controller; When the driver leaves, the seat OPS switch is turned off, and a second status signal is input to the controller; The controller is configured to periodically scan the signal of the seat OPS switch at a settable scan period T; and when the second state signal is scanned and the state continues for more than a first preset time threshold t, output the safety control signal. The scanning period T and the first preset time threshold t are both parameterized by the controller.

3. The electronic control system with OPS function according to claim 2, characterized in that, The controller is also configured to: after outputting the safety control signal, maintain gear lock on the electronically controlled transmission when the signal of the seat OPS switch changes from the second state signal to the first state signal; and only unlock and restore normal control logic when a signal is subsequently received that the electronically controlled shift lever has returned to the neutral position.

4. The electronic control system with OPS function according to claim 1, characterized in that, The controller is also configured to perform neutral start protection, that is, to allow the output of an engine start permission signal through the output port only when a signal is received that the electronically controlled shift lever is in the neutral position.

5. The electronic control system with OPS function according to claim 1, characterized in that, The controller is configured to: When the CutOff power cut-off switch indicates that the function is enabled, if a braking signal is detected, the electronically controlled transmission will be controlled to return to neutral through the electronically controlled transmission valve group to achieve power cut-off. When the CutOff power cut-off switch indicates that the function is off, even if a braking signal is detected, the current gear of the electronically controlled transmission is maintained through the electronically controlled transmission valve group to keep the power uninterrupted. The operation of returning to neutral during braking is only performed when the CutOff function is activated and the electronically controlled transmission is in a low gear of first or second gear.

6. The electronic control system with OPS function according to claim 1, characterized in that, The system also includes an OPS operating device switch, which is connected to the input port of the controller; The controller is configured to: When both the seat OPS switch and the OPS working device switch are simultaneously received, indicating that the driver is in position, a first control signal is output to allow the hydraulic system of the working device to operate normally. If signals indicating the driver's presence are not received simultaneously, a second control signal is output to lock the hydraulic system of the working device.

7. The electronic control system with OPS function according to claim 6, characterized in that, The controller locks and unlocks the hydraulic system of the working device by controlling the opening and closing of an electrically controlled switch valve located in the hydraulic system circuit of the working device.

8. An electronically controlled transmission, characterized in that, include: The gearbox body contains multiple clutches; The electronic control system as described in any one of claims 1 to 7; The electronically controlled transmission valve group in the electronic control system is integrated on the gearbox body, including multiple electronically proportional valves that are connected one-to-one with the clutches.

9. The electronically controlled transmission according to claim 8, characterized in that, Multiple clutches include a forward clutch and a reverse clutch for controlling forward and reverse directions, and a first-gear clutch, a second-gear clutch, a third-gear clutch and a fourth-gear clutch for controlling specific gear positions; The electronically controlled transmission valve group includes a forward proportional valve, a reverse proportional valve, a first gear proportional valve, a second gear proportional valve, a third gear proportional valve, and a fourth gear proportional valve, which are configured one-to-one with the clutches. The controller is configured to: when the seat OPS switch indicates that the driver has been away from the seat for more than a set time, control the forward proportional valve and / or the reverse proportional valve to disengage the forward clutch and / or the reverse clutch, thereby returning the transmission to neutral. The controller is also configured to: respond to the signal of the CutOff power cut-off switch, switch the control logic of the electronically controlled transmission valve group during braking to achieve power cut-off on flat ground or power holding on slopes; and control the hydraulic pressure build-up process of the corresponding clutch by outputting a specific PWM current curve to the electro-proportional valve to achieve smooth engagement.

10. The electronically controlled transmission according to claim 9, characterized in that, The electronically controlled gear shift lever integrates gear shifting and reversing functions; reversing is achieved by pushing the lever forward or pulling it back to switch between three positions: forward, neutral, and reverse; gear shifting is achieved by rotating the lever to switch between four positions: first gear, second gear, third gear, and fourth gear. The electronically controlled gear shift lever is equipped with a locking button. When the locking button is in the locked state, the gear shifting operation of the electronically controlled gear shift lever is mechanically locked.

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