Automatic speed limiting device for high portal frame walking of diesel fork lift truck

Abstract

The utility model relates to the field of forklifts, in particular to an automatic speed limiting device for high portal frame walking of a diesel fork lift truck, which comprises an electronic accelerator pedal, a stay wire sensor, a speed sensor, a speed limiting controller and an engine controller ECU (electronic control unit). The electronic accelerator pedal outputs an electric signal to the speed limiting controller according to the treading force, the stay wire sensor monitors the height of the portal frame and outputs an electric signal to the speed limiting controller, and the speed sensor detects the running speed and outputs an electric signal to the speed limiting controller; the input end of the speed limiting controller receives electric signals from the electronic accelerator pedal, the pull wire sensor and the speed sensor, and the output end of the speed limiting controller is connected with the engine controller ECU. And the engine controller ECU adjusts the rotating speed of the engine according to the electric signal sent by the speed limiting controller. Through cooperative work of the multiple sensors and the controller, comprehensive monitoring and dynamic speed limiting of the driving state of the forklift are achieved, the rollover risk in the high portal state is effectively reduced, and personnel and property safety is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of forklifts, and in particular to an automatic speed limiting device for the high mast of an internal combustion forklift. Background Technology

[0002] Forklifts, as a common type of industrial material handling equipment, play a vital role in logistics, warehousing, and other fields. However, during operation, especially when the mast is at a high position, the forklift's center of gravity shifts significantly, leading to decreased vehicle stability. In practice, if the driver travels at excessive speed while the mast is high, the forklift is highly susceptible to tipping over, causing accidents that can result in personal injury and property damage.

[0003] Traditional forklift speed limiters primarily operate mechanically or through simple electronic means. These devices often only restrict the vehicle's maximum speed and cannot dynamically adjust based on the forklift's actual operating conditions. For example, some forklifts are equipped with mechanical speed limiters that control speed by limiting engine speed; however, this method is relatively fixed and cannot adapt to different working conditions and operational needs. Furthermore, traditional speed limiters typically cannot monitor the forklift's mast height and travel speed in real time, and cannot automatically adjust the speed when the mast is high to ensure vehicle safety.

[0004] While some forklifts are equipped with electronic speed limiting systems in the current technology, most of these systems rely on a single sensor signal, such as a speed sensor, which cannot comprehensively and accurately determine the forklift's operating status. For example, some electronic speed limiting systems limit the speed solely based on the signal from the vehicle speed sensor, but this design fails to consider the impact of the forklift mast height on vehicle stability, potentially leading to safety hazards even at high mast heights. Furthermore, these systems typically employ simple logic control, unable to flexibly adjust to different operating conditions, and thus fail to meet the high safety and flexibility requirements of modern enterprises for forklifts.

[0005] In summary, existing forklift speed limiting technologies still have shortcomings in terms of safety under high mast conditions and cannot effectively reduce the accident rate. Therefore, developing a speed limiting system that can monitor forklift mast height and travel speed in real time and automatically adjust the speed under high mast conditions is of great significance for improving the safety and reliability of forklifts. Utility Model Content

[0006] The purpose of this invention is to propose an automatic speed limiting circuit for high mast travel of internal combustion forklifts. Through the coordinated work of multiple sensors and controllers, it can achieve comprehensive monitoring and dynamic speed limiting of the forklift's travel status, effectively reducing the risk of tipping over in high mast conditions and ensuring the safety of personnel and property.

[0007] To achieve the above objectives, the present invention provides an automatic speed limiting device for the high mast of an internal combustion forklift, comprising an electronic accelerator pedal, a cable sensor, a speed sensor, a speed limiter, and an engine controller (ECU). The electronic accelerator pedal outputs an electrical signal to the speed limiter based on the pedal pressure. The cable sensor monitors the mast height and outputs an electrical signal to the speed limiter. The speed sensor detects the travel speed and outputs an electrical signal to the speed limiter. The speed limiter receives electrical signals from the electronic accelerator pedal, the cable sensor, and the speed sensor at its input terminal, and its output terminal is connected to the engine controller (ECU). The engine controller (ECU) adjusts the engine speed according to the electrical signals sent by the speed limiter.

[0008] Preferably, the speed limit controller determines whether the forklift is in a high mast state based on the signal from the cable sensor, and when the forklift is in a high mast state and the vehicle speed exceeds the preset limit, it processes the received signal from the electronic accelerator pedal and sends it to the engine controller ECU to reduce the engine speed.

[0009] Preferably, it includes a battery and a key switch, wherein the battery supplies power to the electronic accelerator pedal, the cable sensor, the speed limiter, and the engine controller ECU via the key switch.

[0010] Preferably, a fuse is provided between the battery and the key switch.

[0011] Preferably, the output terminals of the electronic accelerator pedal, the cable sensor, and the speed sensor are connected to the speed limiter controller via twisted-pair shielded cables.

[0012] Preferably, the electronic accelerator pedal is an accelerator pedal that outputs CAN signals, including a pressure sensor and a signal conversion module, used to convert physical displacement into electrical signals and output them in the form of CAN signals.

[0013] Preferably, the pull-wire sensor includes a displacement sensor and a signal processing module, which is connected to the forklift mast via a mechanical pull wire, and is used to monitor the mast height in real time and output an electrical signal.

[0014] Preferably, the speed sensor includes a Hall effect sensor or an optical encoder, installed near the wheel or drive shaft, for monitoring the forklift's travel speed and outputting speed information.

[0015] Preferably, the speed limit controller includes a microprocessor, a signal receiving module, and a logic judgment module, used to receive and process signals from the electronic accelerator pedal, the cable sensor, and the speed sensor, and to judge the driving status of the forklift according to preset logic.

[0016] Preferably, the engine controller ECU includes a signal receiving module and an execution control module, used to adjust the fuel injection quantity and ignition timing of the engine according to the CAN signal sent by the speed limiter controller, thereby reducing the engine speed.

[0017] The beneficial effects of this utility model are as follows:

[0018] The control strategy of this invention is simple and clear, easy to understand and operate. Drivers do not need to learn complex operating procedures to effectively control the forklift's speed, reducing operational difficulty and improving work efficiency. By comprehensively analyzing the signals output by the cable sensor and speed sensor, the speed limit controller can accurately determine whether the vehicle is in a high mast state. This intelligent judgment based on actual operating conditions ensures the rationality and relevance of speed limit control, avoids unnecessary speed restrictions, and improves the forklift's adaptability under different working conditions.

[0019] This invention employs a unique control logic: in the low mast state, the speed limiter directly transmits the electronic accelerator pedal signal to the engine control unit (ECU), ensuring normal power output; while in the high mast state, the speed limiter processes the electronic accelerator pedal signal according to the mast height before transmitting it to the ECU, achieving precise control of vehicle speed. This novel control method not only improves safety but also optimizes the driving experience.

[0020] This invention allows customers to set speed limits according to their specific needs and factory conditions, and multiple mast heights can be set to correspond to different vehicle speeds. This customizability enables the forklift to better adapt to different working environments, meet diverse operational needs, and greatly enhance its practicality and market competitiveness.

[0021] By monitoring the mast height and vehicle speed in real time and automatically adjusting the speed when the mast is high, this invention effectively reduces the risk of forklift tipping over when the mast is high, significantly reduces the probability of accidents, and provides more reliable protection for operators and company property.

[0022] The various components of this invention work together through carefully designed electrical connections and signal transmission methods to form a complete closed-loop control system. This highly integrated design not only improves the stability and reliability of the system but also facilitates maintenance and upgrades, reducing long-term operating costs. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the automatic speed limiting device for the high mast of the internal combustion forklift described in this utility model;

[0024] Figure 2 This is a schematic diagram of the automatic speed limiting device for the high mast of an internal combustion forklift described in this utility model.

[0025] Attached reference numerals: 1. Battery; 2. Fuse; 3. Key switch; 4. Electronic accelerator pedal; 5. Engine control unit (ECU); 6. Cable sensor; 7. Speed ​​limiter; 8. Speed ​​sensor. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] See Figure 1 and Figure 2 This utility model discloses an automatic speed limiting circuit for a high mast forklift, the core structure of which includes a battery 1, a fuse 2, a key switch 3, an electronic accelerator pedal 4, an engine controller ECU 5, a cable sensor 6, a speed limit controller 7, and a speed sensor 8. These components work together through carefully designed electrical connections and signal transmission methods to ensure the safe operation of the forklift in high mast mode.

[0028] Battery 1 serves as the core power source for the entire circuit, with its positive terminal connected to the ignition switch 3 via fuse 2. One end of fuse 2 is connected to the positive terminal of battery 1, and the other end is connected to the input terminal of ignition switch 3. Fuse 2 not only provides overload protection but also ensures that current is transmitted within a safe range. Ignition switch 3 acts as the master switch for the circuit, with its output terminals connected to the power input terminals of the electronic accelerator pedal 4, engine control unit (ECU) 5, cable sensor 6, and speed limiter 7, respectively. This design ensures that all relevant components receive a stable power supply simultaneously when ignition switch 3 is powered on.

[0029] The electronic accelerator pedal 4 is an accelerator pedal that outputs a CAN signal. Its construction includes a pressure sensor and a signal conversion module. When the driver presses the accelerator pedal, the pressure sensor converts the physical displacement into an electrical signal, which is then processed internally and output as a CAN signal. The output of the electronic accelerator pedal 4 is connected to the speed limiter controller 7 via a twisted-pair shielded cable to ensure stable signal transmission and interference resistance.

[0030] The cable sensor 6 is a device for real-time monitoring of the forklift mast height, containing a displacement sensor and a signal processing module. The cable sensor 6 is connected to the mast via a mechanical cable. When the mast height changes, the displacement sensor detects the displacement of the cable and converts it into an electrical signal output. The output of the cable sensor 6 is also connected to the speed limiter 7 via a twisted-pair shielded cable to transmit mast height information.

[0031] Speed ​​sensor 8 is used to monitor the forklift's travel speed. It contains a Hall effect sensor or optical encoder. Mounted near the wheels or drive shaft, speed sensor 8 generates pulse signals by detecting rotational speed and converts them into speed information output. The output of speed sensor 8 is connected to the speed limit controller 7 via a twisted-pair shielded cable to ensure the real-time performance and accuracy of the speed data.

[0032] The speed limiter controller 7 is the core processing unit of the entire circuit, internally containing a microprocessor, a signal receiving module, and a logic judgment module. The input terminals of the speed limiter controller 7 receive the CAN signal from the electronic accelerator pedal 4, the mast height signal from the cable sensor 6, and the speed signal from the speed sensor 8. The speed limiter controller 7 determines whether the forklift is in a high mast state based on the signal from the cable sensor 6. If it is in a high mast state, the speed limiter controller 7 further determines whether the current vehicle speed exceeds a preset limit based on the signal from the speed sensor 8. The output terminal of the speed limiter controller 7 is connected to the engine controller ECU 5. When the vehicle speed exceeds the limit, the speed limiter controller 7 processes the received CAN signal from the electronic accelerator pedal 4 and sends the processed signal to the engine controller ECU 5.

[0033] The engine controller ECU5 is the engine control and management unit. It can adjust the engine speed according to the converted CAN message sent by the speed limiter 7. Internally, it includes a signal receiving module and an execution control module. The engine controller ECU5 receives the CAN signal sent by the speed limiter 7 and adjusts the engine's fuel injection quantity and ignition timing according to the signal content, thereby reducing the engine speed and bringing the forklift's travel speed down to a safe range.

[0034] All connections between components (CAN signals) use twisted-pair shielded cables. This design effectively reduces electromagnetic interference and ensures the stability and reliability of signal transmission. The speed limiter 7 is connected to the cable sensor 6, engine controller ECU 5, electronic accelerator pedal 4, and speed sensor 8, forming a complete closed loop for signal transmission and processing.

[0035] The implementation principle of this utility model is as follows: When the key switch 3 is powered on, the speed limiter 7 judges the driving status of the vehicle based on the signals from the cable sensor 6 and the speed sensor 8. Specifically, it determines whether the vehicle is in a high mast state based on the signal from the cable sensor 6. If the vehicle is not in a high mast state, the vehicle speed is not limited. If the vehicle is in a high mast state, it further judges the signal from the speed sensor 8. When the vehicle speed is less than the set speed limit, the vehicle continues to operate in its current state. When the vehicle speed is greater than the set speed limit, the speed limiter 7 processes the signal received from the electronic accelerator pedal 4 and sends it to the engine controller ECU 5, thereby controlling the engine operation, causing the engine speed to decrease accordingly, and the vehicle speed to decrease.

[0036] This design allows for customized speed limits based on factory conditions. When the forklift is in a high mast position, the speed is automatically limited, effectively reducing the probability of accidents and protecting personnel and property. Customers can also set their own speed limits according to specific factory conditions, further enhancing flexibility and adaptability. The coordinated operation of the entire circuit not only improves forklift safety but also optimizes the user experience, providing a reliable guarantee for efficient operation in industrial environments.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An automatic speed limiting device for the high mast of an internal combustion forklift, characterized in that, The system includes an electronic accelerator pedal (4), a cable sensor (6), a speed sensor (8), a speed limiter (7), and an engine controller (ECU) (5). The electronic accelerator pedal (4) outputs an electrical signal to the speed limiter (7) based on the pedal pressure. The cable sensor (6) monitors the mast height and outputs an electrical signal to the speed limiter (7). The speed sensor (8) detects the driving speed and outputs an electrical signal to the speed limiter (7). The speed limiter (7) receives electrical signals from the electronic accelerator pedal (4), the cable sensor (6), and the speed sensor (8) at its input terminal, and its output terminal is connected to the engine controller (ECU) (5). The engine controller (ECU) (5) adjusts the engine speed according to the electrical signal sent by the speed limiter (7).

2. The automatic speed limiting device for the high mast of an internal combustion forklift according to claim 1, characterized in that, The speed limit controller (7) determines whether the forklift is in a high mast state based on the signal from the cable sensor (6), and when the forklift is in a high mast state and the vehicle speed exceeds the preset limit, it processes the signal received from the electronic accelerator pedal (4) and sends it to the engine controller ECU (5) to reduce the engine speed.

3. The automatic speed limiting device for the high mast of an internal combustion forklift according to claim 1 or 2, characterized in that, It includes a battery (1) and a key switch (3), wherein the battery (1) supplies power to the electronic accelerator pedal (4), the cable sensor (6), the speed limiter (7) and the engine controller ECU (5) via the key switch (3).

4. The automatic speed limiting device for the high mast of an internal combustion forklift according to claim 3, characterized in that, A fuse (2) is provided between the battery (1) and the key switch (3).

5. An automatic speed limiting device for the high mast of an internal combustion forklift according to claim 1 or 2, characterized in that, The outputs of the electronic accelerator pedal (4), the cable sensor (6), and the speed sensor (8) are connected to the speed limiter (7) via twisted-pair shielded cables.

6. An automatic speed limiting device for the high mast of an internal combustion forklift according to claim 1 or 2, characterized in that, The electronic accelerator pedal (4) is an accelerator pedal that outputs CAN signals. It includes a pressure sensor and a signal conversion module, which is used to convert physical displacement into electrical signals and output them in the form of CAN signals.

7. The automatic speed limiting device for the high mast of an internal combustion forklift according to claim 6, characterized in that, The pull-wire sensor (6) includes a displacement sensor and a signal processing module. It is connected to the forklift mast via a mechanical pull wire and is used to monitor the mast height in real time and output an electrical signal.

8. The automatic speed limiting device for the high mast of an internal combustion forklift according to claim 7, characterized in that, The speed sensor (8) includes a Hall effect sensor or an optical encoder, which is installed near the wheel or drive shaft to monitor the forklift’s travel speed and output speed information.

9. The automatic speed limiting device for the high mast of an internal combustion forklift according to claim 8, characterized in that, The speed limit controller (7) includes a microprocessor, a signal receiving module and a logic judgment module, used to receive and process signals from the electronic accelerator pedal (4), the cable sensor (6) and the speed sensor (8), and to judge the driving status of the forklift according to preset logic.

10. The automatic speed limiting device for the high mast of an internal combustion forklift according to claim 9, characterized in that, The engine controller ECU (5) includes a signal receiving module and an execution control module, which are used to adjust the fuel injection quantity and ignition timing of the engine according to the CAN signal sent by the speed limit controller (7), thereby reducing the engine speed.

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