Folklift speed control system

Abstract

The present invention provides a speed control device for a forklift, comprising: a risk detection means mounted on a forklift to detect a dangerous situation while driving; and a motion control unit that receives a pedal operation signal generated through an accelerator pedal of the forklift, processes the pedal operation signal according to the risk detection signal of the risk detection means, and transmits it to an electronic control unit; wherein, when a risk detection signal is generated from the risk detection means, the motion control unit processes the signal value of the pedal operation signal to be reduced and transmits it to the electronic control unit, and the driving speed of the forklift is controlled according to the pedal operation signal transmitted from the motion control unit to the electronic control unit.

Description

Technology Field

[0001] The present invention relates to a speed control device for a forklift. More specifically, the invention relates to a speed control device for a forklift that can further enhance safety by decelerating the driving speed of the forklift in advance in various dangerous situations that may occur while the forklift is in operation, and can stably control the driving speed by comprehensively considering the operator's operating state and the work environment, while also safely resuming driving without sudden acceleration even after the danger is resolved. Background Technology

[0002] Generally, forklifts are widely used in industrial sites for loading and transporting heavy loads, and they have the advantage of high work efficiency and maneuverability.

[0003] However, forklifts are often operated in confined spaces where the operator's visibility is limited, and various risk factors exist, such as heavy loading, the mast being raised, sudden turns, and the approach of nearby workers. In such situations, if the operator presses the accelerator pedal deeply or accelerates suddenly, it can lead to serious industrial accidents, such as vehicle rollover, collision, or contact with workers.

[0004] To prevent such risks, various technologies have been proposed to limit or decelerate vehicle speeds. However, as these technologies fail to adequately reflect the complex risk factors of work sites or have limitations in performing immediate and precise control in hazardous situations, there is a persistent need for safer and more reliable speed control technologies. Prior art literature

[0005] Korean Registered Patent No. 10-2728976 The problem to be solved

[0006] The present invention was invented to solve the problems of the prior art, and the objective of the present invention is to provide a speed control device for a forklift that can further improve safety and prevent safety accidents by reducing the driving speed of the forklift in advance in various dangerous situations that may occur while the forklift is driving.

[0007] Another objective of the present invention is to provide a speed control device for a forklift that can stably control the driving speed and safely resume driving without sudden acceleration even after the danger is released, by comprehensively considering the driver's operating state and the working environment. means of solving the problem

[0008] The present invention provides a speed control device for a forklift, comprising: a risk detection means mounted on a forklift to detect a dangerous situation while driving; and a motion control unit that receives a pedal operation signal generated through an accelerator pedal of the forklift, processes the pedal operation signal according to the risk detection signal of the risk detection means, and transmits it to an electronic control unit; wherein, when a risk detection signal is generated from the risk detection means, the motion control unit processes the signal value of the pedal operation signal to be reduced and transmits it to the electronic control unit, and the driving speed of the forklift is controlled according to the pedal operation signal transmitted from the motion control unit to the electronic control unit.

[0009] At this time, the operation control unit may continuously reduce the signal value of the pedal operation signal while the risk detection signal of the risk detection means is maintained, and when the risk detection signal is maintained and then disappears, transmit the pedal operation signal in a non-pressure state to the electronic control unit without reducing the signal value of the pedal operation signal after a new pedal operation signal is generated from the accelerator pedal.

[0010] In addition, the speed control device of the forklift further includes an alarm device mounted on the forklift that indicates a dangerous condition in a visual or auditory manner, and the operation control unit can control the operation so that the alarm device operates as a dangerous detection signal is generated from the dangerous detection means.

[0011] In addition, the operation control unit can control the operation so that the alarm device continues to operate while the risk detection signal of the risk detection means is maintained, and when the risk detection signal is maintained and then disappears, it can control the operation so that the alarm device stops operating after a new pedal operation signal in a non-pressure state is generated from the accelerator pedal.

[0012] In addition, the speed control device of the forklift further includes a deceleration setting switch formed to allow a user to set a deceleration ratio for the driving speed, and the operation control unit can reduce the signal value of the pedal operation signal according to the deceleration ratio set through the deceleration setting switch.

[0013] In addition, the operation control unit may, when the signal value of the danger detection signal is greater than or equal to a preset threshold, convert the pedal operation signal into a pedal operation signal in a non-pressure state and transmit it to the electronic control unit, and simultaneously generate a brake operation signal and transmit it to the electronic control unit.

[0014] In addition, the risk detection means may include at least one of a lift sensor that detects the up and down operating position of the lift, a load measuring sensor that measures the load acting on the lift, a distance sensor that detects whether there is a person or object in the surrounding space of the forklift, and a steering angle measuring sensor that can measure the steering angle of the forklift. Effects of the invention

[0015] According to the present invention, by processing the accelerator pedal signal in the operation control unit and transmitting it to the electronic control unit, it is possible to prevent instantaneous entry into overspeed in dangerous situations, and by ensuring that normal driving is switched only when the accelerator pedal returns to a non-pressure state even after the danger detection signal is released, it is possible to prevent sudden acceleration when the danger is released, thereby providing a safer driving environment.

[0016] In addition, if the danger signal exceeds a threshold, the pedal signal is converted into a signal indicating a no-pressure state, and at the same time, a brake signal or a neutral signal for the forward / reverse lever is output, thereby enabling an immediate emergency stop and further enhancing safety.

[0017] In addition, by applying various risk detection sensors in combination, it is possible to detect hazardous situations at the work site in a detailed and comprehensive manner and enable customized speed control accordingly.

[0018] In addition, by activating the alarm device when a danger detection signal is generated, the dangerous situation can be clearly conveyed to the driver and the operator, and by stopping the alarm device after the accelerator pedal returns to a non-pressure state, it is possible to enable the driver to more accurately recognize the dangerous situation and the current driving situation. Brief explanation of the drawing

[0019] FIG. 1 is a block diagram illustrating the functional classification of the configuration of a speed control device for a forklift according to one embodiment of the present invention. FIG. 2 is a graph illustrating the speed control process of a speed control device of a forklift according to one embodiment of the present invention. Specific details for implementing the invention

[0020] Hereinafter, specific embodiments for implementing the present invention will be described in detail with reference to the drawings.

[0021] First, it should be noted that when assigning reference numerals to the components of each drawing, the same components are assigned the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the present invention, if it is determined that a detailed description of related known components or functions could obscure the essence of the invention, such detailed description is omitted.

[0022] Furthermore, when it is stated that one component is 'connected,' 'supported,' 'connected,' 'supplied,' 'transmitted,' or 'contacted' with another component, it should be understood that while the connection, support, connection, supply, transmission, or contact may be direct to that other component, there may also be other components present in between.

[0023] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0024] Furthermore, it should be noted in advance that expressions such as "upper side," "lower side," and "side" in this specification are described based on the drawings, and may be expressed differently if the orientation of the object changes. For the same reason, some components in the attached drawings may be exaggerated, omitted, or schematically depicted, and the size of each component does not entirely reflect its actual size.

[0025] Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but such components are not limited by such terms. These terms are used solely for the purpose of distinguishing one component from another.

[0026] The meaning of "comprising" as used in the specification is to specify certain characteristics, regions, integers, steps, actions, elements, and / or components, and does not exclude the existence or addition of other specific characteristics, regions, integers, steps, actions, elements, components, and / or groups.

[0027] FIG. 1 is a block diagram illustrating the configuration of a speed control device for a forklift according to one embodiment of the present invention, functionally classified, and FIG. 2 is a graph illustrating the speed control process of a speed control device for a forklift according to one embodiment of the present invention.

[0028] The speed control device for a forklift according to the present invention is a device that reduces the driving speed of a forklift when a dangerous situation is detected during the driving process of the forklift, and may be configured to include a danger detection means (300) and an operation control unit (200). In addition, it may further include a speed setting switch (400) and an alarm device (500).

[0029] Generally, a forklift is basically equipped with an accelerator pedal (100) for controlling the acceleration of the vehicle according to the driver's foot movements, and an electronic control unit (ECU, 600) that receives various control signals, including signals input from the accelerator pedal (100), and controls an engine or a drive motor.

[0030] The risk detection means (300) is installed to monitor the working environment and driving conditions of the forklift in real time, and can be configured to monitor the driving environment from multiple angles by combining various types of sensors rather than a single sensor.

[0031] For example, the danger detection means (300) may be composed of at least one of a lift sensor (310) that detects the up and down position of the lift, a load measuring sensor (320) that measures the load acting on the lift, a distance sensor (330) that detects a person or object present around the forklift, and a steering angle measuring sensor (340) that measures the steering angle of the forklift. These multiple sensors may be used individually, but multiple sensors may be combined and used in combination, thereby increasing the reliability of deceleration control according to dangerous situations.

[0032] The lift sensor (310) detects the lifting position of the lift. Since the risk of overturning increases as the center of gravity of the load rises when the lift rises above a certain height, the motion control unit (200) can determine the dangerous situation differently according to the lifting stage of the lift measured by the lift sensor (310). The load measurement sensor (320) measures the actual load acting on the lift, and the motion control unit (200) can determine the dangerous situation in stages by converting the load measured by the load measurement sensor (320) into a ratio relative to the rated load. In particular, since the risk of overturning increases when a heavy load is loaded and a sharp turn occurs simultaneously, it can generate a stronger deceleration or stop command under complex conditions in conjunction with the steering angle measurement sensor (340). The distance sensor (330) may include ultrasonic, LiDAR, infrared sensors, etc., and measures the distance to people or objects around the forklift. The motion control unit (200) can divide the danger zone into three stages based on distance (e.g., safe distance, caution distance, stop distance), reduce speed in the caution section, and generate an immediate stop command in the stop section. Additionally, if a person is detected, it can generate a control signal to operate more conservatively than an object even at the same distance. The steering angle measuring sensor (340) detects the steering angle, and the motion control unit (200) can generate a control signal to limit the speed of the forklift in stages if the steering angle measured by the steering angle measuring sensor (340) is greater than a certain angle. In particular, since the risk of overturning increases when combined with a lift raising state or a heavy load state, it can be controlled to impose stronger restrictions in this case.

[0033] The operation control unit (200) is connected between the accelerator pedal (100) and the electronic control unit (600) to receive a pedal operation signal generated through the accelerator pedal (100) of the forklift, and processes the pedal operation signal according to the danger detection signal of the danger detection means (300) and transmits it to the electronic control unit (600).

[0034] More specifically, when a danger detection signal is generated from the danger detection means (300), the operation control unit (200) can reduce the signal value of the pedal operation signal and transmit it to the electronic control unit (600). In this way, the driving speed of the forklift can be adjusted according to the pedal operation signal transmitted from the operation control unit (200) to the electronic control unit (600). Here, reducing the signal value of the pedal operation signal and transmitting it means converting the signal to a size lower than the original output value corresponding to the degree to which the driver pressed the accelerator pedal and transmitting it to the electronic control unit (600), thereby ensuring that the actual driving speed of the vehicle is maintained at a level limited to the driver's operation.

[0035] Conventional forklift speed control systems operate based on speed sensors mounted on the vehicle. This is a post-control method that reduces the output of the engine or motor only after detecting that the vehicle has exceeded a set speed limit. Since control begins only after the driver has already entered a state of overspeeding, this method can result in a slow response and increases the risk of cargo instability or overturning due to sudden deceleration. Furthermore, because speed sensors provide only the single piece of information known as the current speed, there are limitations in comprehensively considering various risk factors such as lift height or steering angle.

[0036] In contrast, the present invention adopts a method of reducing the driver's pedal operation signal value itself by installing an operation control unit (200) between the accelerator pedal (100) and the electronic control unit (600). This is a preventive control method, and even if the driver presses the accelerator pedal (100) all the way down, the operation control unit (200) reduces the signal value of the pedal operation signal according to the situation detected by the danger detection means (300) and transmits it to the electronic control unit (600), so that the vehicle can be controlled to a deceleration state immediately in a dangerous situation.

[0037] In accordance with this method, the present invention performs control preemptively at the acceleration input stage rather than retrospectively limiting the speed, which is the driving result value, thereby preventing entry into a dangerous situation at excessive speed and enabling customized speed control according to various risk factors.

[0038] Meanwhile, the motion control unit (200) continuously processes the signal value of the pedal operation signal to be reduced and transmits it to the electronic control unit (600) while the danger detection signal is maintained. Even after the danger detection signal disappears, the deceleration state is maintained until the driver completely releases the accelerator pedal (100) and an idle state signal is generated.

[0039] That is, the operation control unit (200) continuously reduces the signal value of the pedal operation signal while the danger detection signal of the danger detection means (300) is maintained, and when the danger detection signal is maintained and then disappears, it transmits the signal value of the pedal operation signal to the electronic control unit (600) without reducing it only after a new pedal operation signal in a non-pressure state is generated from the accelerator pedal (100).

[0040] This control method fundamentally prevents the vehicle from suddenly accelerating when a dangerous situation is released while the driver is unconsciously keeping the pedal pressed. Therefore, even after the dangerous situation ends, the pedal must be returned to its initial position to resume normal speed, and through this process, the driver consciously resumes driving.

[0041] Meanwhile, the forklift may be equipped with an alarm device (500) that indicates a dangerous condition in a visual or auditory manner. The alarm device (500) may include a warning light and a buzzer, and the operation control unit (200) may control the operation so that the alarm device (500) operates when a danger detection signal is generated from the danger detection means (300).

[0042] At this time, the operation control unit (200) controls the operation so that the alarm device (500) continues to operate continuously while the danger detection signal is maintained, and when the danger detection signal is maintained and then disappears, controls the operation so that the alarm device (500) stops operating only after a new pedal operation signal in a non-pressure state is generated from the accelerator pedal (100).

[0043] According to this control method, when the danger detection signal is not released, the alarm device (500) continues to operate to notify the driver and surrounding workers that the dangerous situation is continuing, and the alarm is stopped after the pedal returns to an idle state. Through this, the driver can intuitively recognize the progress of the deceleration control and whether it has been released.

[0044] In this way, the operation control unit (200) controls the deceleration and alarm operation states to be released only after the pedal returns to a non-pressure state following the deceleration control and alarm operation state according to the danger detection signal, thereby blocking sudden rapid acceleration immediately after the danger is released and maximizing on-site stability.

[0045] FIG. 2 illustrates, by way of example, the state of speed change of a forklift according to the operation control of such operation control unit (200). FIG. 2 (a) is the process of speed change of a general forklift according to the prior art, and FIG. 2 (b) is the process of speed change of a forklift according to the present invention.

[0046] As illustrated in FIG. 2 (a) and (b), the forklift accelerates from the start of driving until time t1 to reach a maximum speed of v2. If a danger detection signal occurs at time t2 while driving at v2, the forklift is decelerated to a preset deceleration speed of v1 (time t3). Once the deceleration process is complete, the forklift drives at the deceleration speed of v1, even if the accelerator pedal (100) is pressed to the maximum.

[0047] When the danger detection signal disappears at time t4, a typical forklift accelerates rapidly to the maximum speed v2 at time t4, as shown in (a) of FIG. 2. Therefore, after the danger detection signal disappears, an unintended rapid increase in speed occurs, which can cause safety accidents.

[0048] In one embodiment of the present invention, when the danger detection signal is extinguished as described above, the pedal can be re-accelerated after returning to a non-pressure state. Therefore, as shown in FIG. 2 (b), while the driver is operating in a non-pressure state, the speed is further decelerated until it becomes 0 at time t4 (until time t4'), and then when the driver presses the accelerator pedal, the speed gradually increases until it reaches a maximum speed v2 at time t5. Thus, even if the danger detection signal is extinguished, sudden acceleration does not occur, and the speed increases steadily and gradually according to the driver's operation, thereby maintaining driving safety.

[0049] The speed control method of the present invention, as shown in FIG. 2(b), controls the vehicle to return to a normal driving mode only after passing through a no-pressure state immediately after the danger detection signal disappears, thereby fundamentally preventing the problem of rapid acceleration that occurs in conventional technology and improving safety at the work site.

[0050] Meanwhile, the forklift may be equipped with a deceleration setting switch (400) that allows the user to set the deceleration ratio for the driving speed.

[0051] This deceleration setting switch (400) can be provided so that an administrator can set the deceleration ratio considering the characteristics of the workplace or safety regulations. At this time, the motion control unit (200) can limit the maximum driving speed of the forklift to a desired level by processing the signal value of the pedal operation signal to be reduced according to the deceleration ratio set by the deceleration setting switch (400) and transmitting it to the electronic control unit (600). In particular, since the deceleration ratio can be set in various ways through the deceleration setting switch (400), the deceleration ratio can be applied large or small depending on the user's needs, thereby allowing the magnitude of the deceleration of the forklift to be appropriately adjusted according to the site conditions.

[0052] Meanwhile, the operation control unit (200) can perform immediate emergency stop control beyond simple deceleration control when the signal value of the danger detection signal is greater than or equal to a preset threshold.

[0053] Specifically, the operation control unit (200) converts the pedal operation signal input from the accelerator pedal (100) into a signal of no-pressure state and transmits it to the electronic control unit (600), thereby preventing further acceleration signals from being input to the electronic control unit even if the driver is pressing the accelerator pedal. At the same time, the operation control unit (200) can immediately switch the vehicle to a stopped state by generating a separate brake operation signal and transmitting it to the electronic control unit (600).

[0054] At this time, the emergency stop method may be implemented differently depending on the driving method of the forklift. In the case of a forklift equipped with an electronic brake pedal, the operation control unit (200) directly controls the electrical signal of the brake pedal so that the electronic control device (600) immediately generates braking force. On the other hand, in a hydraulic drive type forklift, since it is difficult to control immediate stopping with only the brake signal, the operation control unit (200) outputs a signal to forcibly switch the signal of the forward / reverse lever to a neutral state to cut off the driving force, and the vehicle can be immediately decelerated and stopped.

[0055] Accordingly, when a dangerous situation is very urgent, the forklift can be controlled to an emergency stop state beyond a simple deceleration state, and can effectively prevent serious accidents such as rollover or collision.

[0056] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0057] 100: Accelerator pedal 200: Operation control unit 300: Risk Detection Means 310: Lift sensor 320: Load measuring sensor 330: Distance sensor 340: Steering angle measurement sensor 400: Deceleration setting switch 500: Alarm device 600: Electronic Control Unit

Claims

Claim 1 A risk detection means mounted on a forklift to detect a dangerous situation while driving; and a motion control unit that receives a pedal operation signal generated through the accelerator pedal of the forklift, processes the pedal operation signal according to the risk detection signal of the risk detection means, and transmits the result to an electronic control unit. A speed control device for a forklift, comprising a deceleration setting switch formed to allow a user to set a deceleration ratio for the driving speed, wherein the operation control unit, when a danger detection signal is generated from the danger detection means, processes the signal value of the pedal operation signal to be reduced and transmits it to the electronic control unit, and while the danger detection signal from the danger detection means is generated and maintained, continues to process the signal value of the pedal operation signal to be reduced and transmits it to the electronic control unit, and when the danger detection signal is maintained and then disappears, transmits the pedal operation signal to the electronic control unit without processing the signal value to be reduced after a new pedal operation signal in a non-pressure state is generated from the accelerator pedal, and the operation control unit processes the signal value of the pedal operation signal to be reduced according to the deceleration ratio set through the deceleration setting switch, and the driving speed of the forklift is controlled according to the signal value of the pedal operation signal transmitted from the operation control unit to the electronic control unit. Claim 2 delete Claim 3 In claim 1, the speed control device of the forklift further comprises an alarm device mounted on the forklift that indicates a dangerous condition in a visual or auditory manner, and the operation control unit controls the operation of the alarm device to operate as a dangerous detection signal is generated from the dangerous detection means. Claim 4 A speed control device for a forklift according to claim 3, wherein the operation control unit controls the operation so that the alarm device continues to operate while the risk detection signal of the risk detection means is maintained, and controls the operation so that the alarm device stops operating after a new pedal operation signal in a non-pressure state is generated from the accelerator pedal when the risk detection signal is maintained and then extinguished. Claim 5 delete Claim 6 A speed control device for a forklift according to claim 1, wherein the operation control unit converts the pedal operation signal into a pedal operation signal in a non-pressure state and transmits it to the electronic control unit when the signal value of the danger detection signal is greater than or equal to a preset reference value, and simultaneously generates a brake operation signal and transmits it to the electronic control unit. Claim 7 A speed control device for a forklift according to claim 1, wherein the risk detection means comprises at least one of a lift sensor that detects the up and down operating position of the lift, a load measuring sensor that measures the load acting on the lift, a distance sensor that detects whether there is a person or object in the surrounding space of the forklift, and a steering angle measuring sensor that can measure the steering angle of the forklift.

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