Weight change system

Abstract

When using a picking lift that operates at heights, ensure that the operator works carefully. [Solution] The weight change system is a weight change system used in a forklift 1 equipped with a driver's cab 6, and comprises a weight change unit, a weight determination unit, and a change command unit. The weight change unit is configured to change the weight of at least one of the steering wheel 15, pedal 17, and accelerator grip of the forklift 1, and the height detection unit is configured to detect the height PH of the driver's cab 6. The weight determination unit determines to increase the weight of at least one of the steering wheel 15, pedal 17, and accelerator grip according to the height PH of the driver's cab 6, and the change command unit controls the weight change unit to change the weight of at least one of the steering wheel 15, pedal 17, and accelerator grip according to the determination of the weight determination unit.

Description

Technical Field

[0001] The present invention relates to a forklift, particularly a weight change system for a picking lift.

Background Art

[0002] Conventionally, as disclosed in Patent Document 1, there is a forklift called a picking lift. This forklift has an operator's cab in front of the vehicle body, and the operator's cab is provided with a handle, an accelerator grip, a brake pedal, and a lift button for operating the forklift. And, left and right forks extending in the horizontal direction are provided on the operator's cab, and the operator's cab and the forks are configured to move up and down along the mast of the forklift. The driver gets on this operator's cab and performs operations such as forward movement, backward movement, turning, stopping, and lifting and lowering of the forks of the forklift.

[0003] When the driver raises the operator's cab, picking work may be performed at a high place, and the height of this high place may reach 5 m from the ground. Therefore, in order to protect the safety of the driver, a safety bar and a safety belt surrounding the driver are provided on the operator's cab. However, especially novice drivers may have a reduced concentration due to the fear of heights as the height of the work increases. Also, since accidents are likely to occur during high-altitude work, the driver may lack concentration due to habit when he or she should maintain concentration to perform the work.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the problem that the present invention aims to solve is to provide a system that allows the operator to work carefully in a picking lift used for work at high altitudes. [Means for solving the problem]

[0006] To solve the above problems, the weight changing system according to the present invention is A weight change system used in a forklift equipped with a driver's cab, A weight changing unit for changing the weight of at least one of the steering wheel, pedals, and accelerator grip of a forklift, A height detection unit that detects the height of the driver's cab, A weight determination unit that determines to increase the weight of at least one of the steering wheel, pedals, and accelerator grip according to the height of the driver's cab, The system includes a change command unit that controls a weight changing unit to change the weight of at least one of the steering wheel, pedals, and accelerator grip, according to the determination of a weight determination unit.

[0007] The above weight changing system is preferably, The weight determination unit determines that when the height of the driver's cab is above a predetermined height, the weight of at least one of the steering wheel, pedals, and accelerator grip becomes heavier.

[0008] The above weight changing system is preferably, The weight determination unit determines that when the height of the driver's cab is below a predetermined height, the weight of at least one of the steering wheel, pedals, and accelerator grip will not be changed.

[0009] The above weight changing system is preferably, The vehicle further includes a change notification unit that informs the driver that the weight of at least one of the steering wheel, pedals, and accelerator grip will be changed.

[0010] To solve the above problems, the forklift according to the present invention is equipped with a weight changing system as described in any of the above.

[0011] To solve the above problems, the weight changing program according to the present invention is: A program used in a weight changing system comprising a weight changing unit that changes the weight of at least one of the steering wheel, pedals, and accelerator grip of a forklift having a driver's cab, a height detection unit that detects the height of the driver's cab, and a computer, On the computer, A weight determination unit that determines to increase the weight of at least one of the steering wheel, pedals, and accelerator grip according to the height of the driver's cab, A change command unit controls a weight change unit according to the determination of the weight determination unit, causing it to change the weight of at least one of the steering wheel, pedals, and accelerator grip. [Effects of the Invention]

[0012] The weight adjustment system according to the present invention allows the driver to work carefully by changing the weight of at least one of the steering wheel, pedals, and accelerator grip according to the height of the driver's cab. [Brief explanation of the drawing]

[0013] [Figure 1] This is a side view showing a forklift relating to one embodiment of the present invention. [Figure 2] This is a perspective view showing the control panel of a forklift. [Figure 3] This is a block diagram of the weight change system. [Figure 4] This is a side view illustrating the operation of a forklift. [Figure 5] This is a flowchart illustrating the operation of the weight change system. [Modes for carrying out the invention]

[0014] Hereinafter, with reference to the attached drawings, an embodiment of a weight change system according to the present invention and a forklift equipped with the system will be described. The weight change system S according to this embodiment is configured to change the weights of the handle and the accelerator grip, but this is merely an example, and the weight change system according to the present invention may be configured to change the weight of at least one of the handle, the pedal, and the accelerator grip.

[0015] <Configuration of Forklift> FIG. 1 is a side view of the forklift 1 according to this embodiment, and FIG. 2 is a perspective view showing the operation unit of the forklift 1. The forklift 1 is a battery-powered picking lift, but this is merely an example, and the forklift according to the present invention is not limited thereto. The forklift 1 includes a plurality of wheels 2, a vehicle body 3, left and right mast 4, left and right forks 5, an operator's cab 6, a pillar 7, a head guard 8, a handle 15, an accelerator grip 16, a pedal 17, a lift button 18, a speaker 19, a height detection unit 20 (see FIG. 3), a weight change unit 21 (see FIG. 3), and a control unit 30 (see FIG. 3). The system including the speaker 19, the height detection unit 20, the weight change unit 21, and the control unit 30 is the weight change system S according to this embodiment.

[0016] The plurality of wheels 2 includes driven wheels and drive wheels, and the vehicle body 3 is disposed above the drive wheels. The left and right mast 4 are disposed in front of the vehicle body 3 and are configured to be telescopically extendable vertically. The left and right forks 5 are connected to the mast 4 via the operator's cab 6 so as to be liftable and configured to lift and lower the load W along the mast 4.

[0017] The operator's cab 6 is connected to the mast 4 so as to be liftable and configured to carry the driver H and lift and lower along the mast 4. The pillar 7 extends upward from the operator's cab 6 and supports the head guard 8.

[0018] A safety cable C is provided in the driver's cab 6, which is connected to the safety belt SB worn by the driver H to prevent the driver H from falling. In addition, as shown in Figure 2, an operating section is provided in the driver's cab 6, which is equipped with a handle 15, an accelerator grip 16, and an elevator button 18.

[0019] The steering wheel 15 is operated by the driver H to steer the drive wheels and turn the vehicle body 3. In this embodiment, the steering wheel 15 is configured as an electric power steering system, but this is merely one example and is not limited thereto.

[0020] The accelerator grip 16 is configured to be rotatable when held. The accelerator grip 16 is operated by the driver H and is configured to move the forklift 1 forward or backward depending on the direction of rotation, and to accelerate or decelerate forward and reverse movement depending on the amount of rotation. In this embodiment, the accelerator grip 16 has a device that assists the weight of the accelerator grip 16 by electronic control. However, the configuration of the accelerator grip 16 is not particularly limited as long as the weight can be changed, as will be explained later.

[0021] Pedal 17 is a brake pedal, and in this embodiment, it is configured as a so-called deadman's brake. Therefore, the forklift 1 cannot move unless the driver H is pressing pedal 17.

[0022] The lifting / lowering button 18 consists of an upward button and a downward button. The driver's cab 6 and fork 5 move up and down along the mast 4 when the respective buttons are pressed by the driver H.

[0023] In this embodiment, speaker 19 is located on the head guard 8. Speaker 19 emits a warning sound to inform driver H of a weight change, which will be described later. The warning sound may be, for example, "The weight of the steering wheel 15 and accelerator grip 16 will be increased" if the weight of the steering wheel 15 and accelerator grip 16 is to be increased.

[0024] The height detection unit 20 detects the height PH from the road surface G to the driver's cab 6. The height detection method of the height detection unit 20 is not particularly limited. The forklift 1 may further be equipped with a sensor for detecting the height PH of the driver's cab 6, and the height detection unit 20 may use this sensor to detect the height PH of the driver's cab 6. The sensor for detecting the height PH of the driver's cab 6 may be, for example, a distance sensor, a position sensor, or an optical encoder. In this case, the distance sensor may be ultrasonic or laser, and the height PH of the driver's cab 6 is detected by emitting ultrasonic waves or irradiating a laser to detect the distance from the bottom surface of the driver's cab 6 to the road surface G. In the case of a position sensor, the position sensor is placed on the lift cylinder of the lifting device that raises and lowers the mast 4, and the height PH of the driver's cab 6 is detected by detecting the extension and retraction state of the lift cylinder. In the case of an optical encoder, the optical encoder is attached to a shaft (not shown) that rotates in conjunction with the raising and lowering of the driver's cab 6, and the height PH of the driver's cab 6 is detected by counting the number of rotations of the shaft.

[0025] The weight adjustment unit 21 changes the operating weight of the handle 15 and the accelerator grip 16 based on commands from the adjustment command unit 307 (see Figure 3), which will be explained later. The weight adjustment unit 21 includes a handle weight adjustment unit that adjusts the weight of the handle 15 and an accelerator grip weight adjustment unit that adjusts the weight of the accelerator grip 16. If the weight adjustment unit 21 is configured to adjust the weight of either the handle 15 or the accelerator grip 16, it will have either the handle weight adjustment unit or the accelerator grip weight adjustment unit.

[0026] The steering wheel weight adjustment unit changes the weight of the steering wheel 15 when the driver H operates it, based on a command from the adjustment command unit 307. In this embodiment, the steering wheel 15 is assisted by electric power steering, which uses an electric motor to provide the force necessary for operating the steering wheel 15. Therefore, the steering wheel weight adjustment unit adjusts this assist force, thereby substantially changing the weight of the steering wheel 15 when the driver H operates it. However, this is merely an example, and the configuration of the steering wheel 15 and the steering wheel weight adjustment unit are not limited to this.

[0027] For example, if the forklift 1 is engine-powered and the steering wheel 15 is assisted in rotation by hydraulic power steering, the steering wheel weight adjustment unit may control the hydraulic pressure to adjust the assist force.

[0028] The accelerator grip weight adjustment unit may be configured, for example, to adjust the assist force of the accelerator grip 16 by electronic control. This effectively changes the weight of the accelerator grip 16 when operated by the driver H. However, this is merely an example, and the configuration of the accelerator grip 16 and the accelerator grip weight adjustment unit are not limited thereto.

[0029] For example, the accelerator grip weight adjustment unit may consist of a device that can adjust the weight of the accelerator grip 16 by means of a spring. Alternatively, the accelerator grip weight adjustment unit may be configured to change the magnitude of the power of each device that responds to the amount of operation of the accelerator grip 16, for example, based on a command from the adjustment command unit 307. In this way, the accelerator grip weight adjustment unit substantially changes the weight of the accelerator grip 16.

[0030] The control unit 30 is comprised of a computer located within the vehicle body 3 and includes a calculation unit, a storage device, and memory. The storage device stores a weight change program that causes the computer to execute as a weight determination unit 305, a change notification unit 306, and a change command unit 307, which will be described later.

[0031] <Functional configuration of the weight change system> Next, the functional configuration of the weight change system S will be described. As shown in Figure 3, the control unit 30 includes a weight determination unit 305, a change notification unit 306, and a change command unit 307.

[0032] The weight determination unit 305 determines that if the height PH (see Figures 1 and 4) of the driver's cab 6 is high, the weight of the steering wheel 15 and the accelerator grip 16 should be increased. This allows the weight determination unit 305 to operate the forklift 1 carefully at high altitudes.

[0033] More specifically, the weight determination unit 305 determines that the weight of the steering wheel 15 and accelerator grip 16 will not be changed (remain at the first weight) when the height PH of the driver's cab 6 is less than a predetermined height. Furthermore, the weight determination unit 305 determines that the weight of the steering wheel 15 and accelerator grip 16 will be increased (to the second weight) when the height PH of the driver's cab 6 is above the predetermined height. In this embodiment, the weight determined by the weight determination unit 305 is in two stages, but this is merely an example; the weight determined by the weight determination unit 305 may be in three or more stages depending on the height PH of the driver's cab 6.

[0034] When the weight determination unit 305 determines that the weight of the steering wheel 15 and accelerator grip 16 should be increased, the change notification unit 306 notifies the driver H of the change in weight of the steering wheel 15 and accelerator grip 16 by voice through the speaker 19. In this way, the change notification unit 306 makes the driver H aware of the change in weight of the steering wheel 15 and accelerator grip 16.

[0035] The change command unit 307 controls the weight change unit 21 according to the determination of the weight determination unit 305 to change the weight of the handle 15 and accelerator grip 16. As a result, the weight change system S allows the driver H to operate the forklift 1 carefully when the driver's cab 6 is higher than a predetermined height.

[0036] <Flowchart of the weight change system> Next, the operation of the weight changing system S according to this embodiment will be explained again with reference to Figures 4 and 5.

[0037] (1) When the forklift 1 moves to the front of the rack R on which the load W is placed (load handling position) and the driver's cab 6 rises (see Figure 4), the weight change system S detects the height PH of the driver's cab 6 using the height detection unit 20 (see S1 in Figure 5).

[0038] (2) Next, the weight changing system S determines the weight of the steering wheel 15 and the accelerator grip 16 based on the height PH of the driver's cab 6 (see S2 in Figure 5).

[0039] (3) Next, when the weight change system S decides to increase the weight of the steering wheel 15 and the accelerator grip 16, it notifies the driver H that the weight of the steering wheel 15 and the accelerator grip 16 will be increased (see S3 in Figure 5), and then increases the weight of the steering wheel 15 and the accelerator grip 16 (see S4 in Figure 5). After that, the driver H operates the accelerator grip 16 and the steering wheel 15 to move the forklift 1 forward, backward, or turn.

[0040] In this way, when the height PH of the driver's cab 6 is high, the weight change system S increases the weight of the steering wheel 15 and accelerator grip 16, allowing the driver H to operate the vehicle carefully and preventing sudden starts, sharp turns, and major operating errors. Conversely, when the height PH of the driver's cab 6 is low, the weight change system S does not increase the weight of the steering wheel 15 and accelerator grip 16, allowing the driver to operate the steering wheel 15 and accelerator grip 16 quickly.

[0041] Although one embodiment of the weight changing system and forklift according to the present invention has been described above, the present invention is not limited to the above embodiment. The weight changing system and forklift according to the present invention may be implemented, for example, by each of the following modifications or by combining each of the modifications.

[0042] <Variation> The weight change system S may be configured to change the weight of the pedal 17, as described above. In this case, the weight change unit 21 further includes a pedal weight change unit. The pedal weight change unit changes the weight of the pedal 17 when the driver H presses down on it, based on a command from the change command unit 307. The pedal weight change unit is composed of, for example, a device that can adjust the weight by hydraulics, or a device that can adjust the weight by a spring. Alternatively, for example, the pedal weight change unit may be an assist device that assists the force applied to the pedal 17. In this case, the pedal weight change unit may adjust the assist force based on a command from the change command unit 307, thereby substantially changing the weight of the pedal 17 when the driver H presses down on it. Or, for example, the pedal weight change unit may be configured to change the magnitude of the power or braking force of each device that responds to the amount of force applied to the pedal 17, based on a command from the change command unit 307. As a result, the pedal weight change unit substantially changes the weight of the pedal 17. Furthermore, the weight determination unit 305 determines the weight of the pedal 17 based on the weight of the driver's cab 6, and the change notification unit 306 notifies the driver H of the change in the weight of the pedal 17 when the weight of the pedal 17 is to be changed. Then, the change command unit 307 controls the weight change unit 21 to change the weight of the pedal 17 according to the determination of the weight determination unit 305.

[0043] • Any of the components of the control unit 30 may be configured, for example, by a server computer located on the cloud. In this case, the weight change system S changes the weight of the pedal 17 and the accelerator grip 16 or either of them by communicating with this server computer.

[0044] The forklift 1 may be equipped with a monitor instead of a speaker 19, and the change notification unit 306 may notify via this monitor that the weight of the accelerator grip 16 and the pedal 17 or either of them will be changed. [Explanation of symbols]

[0045] S Weight change system C Safety Cable G road surface H Driver R Rack PH driver's cab height SB Safety Belt W load 1 Forklift 2 wheels 3. Vehicle Body 4 Mast 5 forks 6. Driver's cab 7 Pillar 8 Headguard 15 Handle 16. Accelerator grip 17 pedals 18. Height adjustment buttons 19 speakers 20 Height detection unit 21 Weight change section 30 Control Unit 305 Weight determination unit 306 Notice of Changes 307 Change Command Unit

Claims

1. A weight change system used in a forklift equipped with a driver's cab, A weight changing unit for changing the weight of at least one of the steering wheel, pedals, and accelerator grip of the forklift, A height detection unit for detecting the height of the driver's cab, A weight determination unit that determines to increase the weight of at least one of the steering wheel, pedals, and accelerator grip according to the height of the driver's cab, A weight changing system comprising: a change command unit that controls the weight changing unit to change the weight of at least one of the handle, pedal and accelerator grip according to the determination of the weight determination unit.

2. The weight changing system according to claim 1, wherein the weight determination unit determines that when the height of the driver's cab is above a predetermined height, the weight of at least one of the steering wheel, pedals, and accelerator grip becomes heavier.

3. The weight changing system according to claim 1, wherein the weight determination unit determines not to change the weight of at least one of the steering wheel, pedals, and accelerator grip when the height of the driver's cab is less than a predetermined height.

4. The weight changing system according to claim 1, further comprising a change notification unit that notifies the driver that the weight of at least one of the steering wheel, the pedal, and the accelerator grip will be changed.

5. A forklift comprising a weight changing system according to any one of claims 1 to 4.

6. A program used in a weight changing system comprising a weight changing unit that changes the weight of at least one of the steering wheel, pedals, and accelerator grip of a forklift having a driver's cab, a height detection unit that detects the height of the driver's cab, and a computer, To the aforementioned computer, A weight determination unit that determines to increase the weight of at least one of the steering wheel, pedals, and accelerator grip according to the height of the driver's cab, A weight change program is executed by a change command unit that controls the weight change unit to change the weight of at least one of the handle, pedal and accelerator grip, according to the determination of the weight determination unit.

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