Weight change system

Abstract

In a forklift equipped with a driver's cab, the operator is instructed to carefully perform the lifting and lowering operations. [Solution] The weight change system S comprises a storage unit 301, a weight change unit 21, a weight determination unit 305, and a change command unit 307. The storage unit 301 stores the height of either or both of the loading and unloading positions. The weight change unit 21 is configured to change the weight of the lifting operation unit 18 that operates the lifting device. The weight determination unit 305 determines to increase the weight of the lifting operation unit 18 according to the height of the loading or unloading position, and the change command unit 307 controls the weight change unit 21 to change the weight of the lifting operation unit 18 according to the determination of the weight determination unit 305.

Description

Technical Field

[0005]

[0001] The present invention relates to a weight change system for a forklift having an operator's cab.

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 by a lifting device. The driver operates the forklift while riding on this operator's cab. When the driver raises the operator's cab, the driver works at a high place. Therefore, in order to protect the safety of the driver, a safety bar surrounding the driver is arranged on the operator's cab.

[0003] Also, for example, attachments such as "lift remote control" and "simple lift remote control" disclosed in Non-Patent Document 1 are disclosed, and an attachment that can attach an operator's cab to a forklift is disclosed. This attachment is configured to be able to move up and down by a remote control provided on the operator's cab.

[0004] By the way, when the loading position and the unloading position are relatively high, it is necessary to operate carefully in order to avoid the operator's cab contacting an obstacle when raising and lowering the operator's cab. However, the higher the working height, the more the concentration may decrease due to the fear of heights. Also, when descending from a relatively high place, it is difficult to grasp the situation on the ground. Therefore, when the loading position and the unloading position are relatively high, it is necessary to perform the lifting and lowering operations more carefully.

Prior Art Documents

Patent Documents

[0005] <​​ Japanese Patent Publication No. 2014-31250 [Non-patent literature]

[0006] [Non-Patent Document 1] Mitsubishi Logisnext homepage, "Attachments", [online], Mitsubishi Logisnext Corporation, logisnext.com, [searched September 18, 2024], Internet<URL:https: / / solutions.logisnext.com / product / product-23 / > [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the problem that the present invention aims to solve is to provide a system that allows the operator to carefully perform the lifting and lowering operation in a forklift equipped with a driver's cab. [Means for solving the problem]

[0008] 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 storage unit that stores the height of either or both of the loading and unloading positions, A weight adjustment unit that changes the weight of the lifting operation unit that operates the lifting device, A weight determination unit that determines how to increase the weight of the lifting operation unit according to the height of the loading or unloading position, The system includes a change command unit that controls a weight changing unit to change the weight of the lifting operation unit according to the determination of a weight determination unit.

[0009] The above weight changing system is preferably, The weight determination unit determines that the weight of the lifting operation unit increases when the height of the loading or unloading position is above a predetermined height.

[0010] The above weight changing system is preferably, The weight determination unit determines that the weight of the lifting / lowering unit should not be changed if the height of the loading or unloading position is less than a predetermined height.

[0011] The above weight changing system is preferably, The memory unit stores the height of the loading or unloading position in the rack as the rack level. The weight determination unit determines that the weight of the lifting operation unit increases when the number of rack levels at the loading or unloading position on the rack is equal to or greater than a predetermined number.

[0012] The above weight changing system is preferably, The memory unit stores the height of the loading or unloading position in the rack as the rack level. The weight determination unit determines that the weight of the lifting and lowering operation unit will not be changed if the number of rack levels at the loading or unloading position on the rack is less than a predetermined number.

[0013] The above weight changing system is preferably, The memory unit further stores the magnitude of the road surface slope at the loading / unloading position related to the loading / unloading position. The weight determination unit changes the weight of the lifting operation unit according to the degree of inclination of the road surface at the loading / unloading position and the height of the loading / unloading position.

[0014] The above weight changing system is preferably, The system further includes a tilt detection unit that detects the magnitude of the slope of the road surface at the loading / unloading position related to the loading / unloading position, The weight determination unit changes the weight of the lifting operation unit according to the degree of inclination of the road surface at the loading / unloading position and the height of the loading / unloading position.

[0015] The above weight changing system is preferably, It is further equipped with a change notification unit that informs the operator that the weight of the lifting / lowering mechanism will be changed.

[0016] In order to solve the above problems, the forklift according to the present invention includes the weight change system described in any of the above.

[0017] In order to solve the above problems, the weight change program according to the present invention is a program used in a weight change system including a weight change unit that changes the weight of the lifting operation unit of a forklift having an operator's cab and a computer, where the computer is caused to a weight determination unit that determines to increase the weight of the lifting operation unit according to the height of the load placement position or the load pickup position, and a change command unit that controls the weight change unit to change the weight of the lifting operation unit according to the determination of the weight determination unit, and is caused to execute.

Effect of the Invention

[0018] The weight change system according to the present invention can cause the driver to perform the lifting operation carefully by changing the weight of the lifting operation unit according to the height of the load pickup position and the load placement position.

Brief Description of the Drawings

[0019] [Figure 1] It is a side view showing a forklift according to an embodiment of the present invention. [Figure 2] It is a perspective view showing an operation unit. [Figure 3] It is a block diagram of a weight change system. [Figure 4] It is a side view showing the operation of a forklift. [Figure 5] It is a flowchart showing the operation of a weight change system.

Mode for Carrying Out the Invention

[0020] Hereinafter, an embodiment of a weight change system according to the present invention and a forklift equipped with the system will be described with reference to the accompanying drawings.

[0021] <Configuration of Forklift> Figure 1 is a side view of the forklift 1 according to this embodiment, and Figure 2 is a perspective view showing the operating section 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 to this. For example, the forklift according to the present invention may be a forklift equipped with a driver's cab as an attachment.

[0022] The forklift 1 comprises multiple wheels 2, a body 3, left and right masts 4, left and right forks 5, a driver's cab 6, pillars 7, a head guard 8, a steering wheel 15, an accelerator grip 16, pedals 17, a lifting / lowering operation unit 18, a speaker 19, a weight changing unit 21 (see Figure 3), a tilt detection unit 23 (see Figure 3), and a control unit 30 (see Figure 3). The system comprising this speaker 19, tilt detection unit 23, weight changing unit 21, and control unit 30 is the weight changing system S according to this embodiment.

[0023] Multiple wheels 2 include driven wheels and drive wheels, and the vehicle body 3 is positioned above the drive wheels. The left and right masts 4 are positioned in front of the vehicle body 3 and are configured to extend and retract vertically. The left and right forks 5 are connected to the masts 4 via the driver's cab 6 so as to be able to move up and down, and are configured to move up and down along the masts 4 by a lifting device (not shown) to raise and lower the load W.

[0024] The driver's cab 6 is connected to the mast 4 so as to be able to move up and down, and is configured to move up and down along the mast 4 with the driver H inside via a lifting device. The pillar 7 extends upward from the driver's cab 6 and supports the head guard 8.

[0025] 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 a lifting / lowering operating section 18.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] The lifting and lowering control unit 18 consists of an upward button and a downward button. In this embodiment, the upward and downward buttons incorporate a spring and a pressure sensor. The spring generates a repulsive force in each button. The pressure sensor is configured to detect the strength of the force applied. The driver's cab 6 and fork 5 move up and down along the mast 4 when the driver H presses each button with a predetermined pressure or greater.

[0030] In this embodiment, speaker 19 is located on the head guard 8. Speaker 19 emits a warning sound to inform the driver H of a weight change, which will be explained later. The warning sound may be, for example, "The weight of the lifting operation unit 18 will be increased" if the weight of the lifting operation unit 18 is increased.

[0031] The weight adjustment unit 21 changes the weight required to operate the lifting / lowering operation unit 18 based on commands from the change command unit 307 (see Figure 3), which will be explained later. The weight adjustment unit 21 may have, for example, solenoid coils (solenoids) located below the up button and the down button, respectively. The weight adjustment unit 21 then adjusts the repulsive force (weight) of each button by adjusting the current flowing through these solenoid coils. This changes the weight of each button.

[0032] Furthermore, the weight adjustment unit 21, for example, arranges a piezoelectric element in parallel with a spring and expands or contracts the piezoelectric element by applying voltage to it. The weight adjustment unit 21 then adjusts the voltage applied to the piezoelectric element to assist or suppress the rebound force (spring force) of each button. In this way, the weight adjustment unit 21 adjusts the rebound force (weight) of each button.

[0033] Alternatively, for example, the weight adjustment unit 21 may substantially adjust the weight of each button by adjusting the pressure value of the pressure sensor that recognizes each button as being pressed.

[0034] The tilt detection unit 23 detects the magnitude of the tilt of the road surface G at the loading / unloading position LP, which is related to the loading / unloading position. The configuration of the tilt detection unit 23 is not particularly limited. For example, the tilt detection unit 23 may have a camera positioned on the forklift 1 to photograph the front, and an analysis unit that analyzes the image generated by the camera to detect the magnitude of the tilt of the vehicle body 3 (tilt of the road surface G). Alternatively, the tilt detection unit 23 may have a sensor that detects the magnitude of the tilt of the road surface G, and the magnitude of the tilt of the loading / unloading position LP may be detected by that sensor.

[0035] 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.

[0036] <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 storage unit 301, a weight determination unit 305, a change notification unit 306, and a change command unit 307.

[0037] The memory unit 301 stores the height WH of the loading and unloading positions related to each loading and unloading operation.

[0038] Figure 4 is a side view showing a rack R on which a load W is placed and a forklift 1 stopped at the loading / unloading position LP. The weight determination unit 305 determines that the higher the height WH (see Figure 4) of the loading or unloading position, the heavier the weight of the lifting / unloading operation unit 18. This allows the weight determination unit 305 to perform lifting / unloading operations at high places with caution. Alternatively, the weight determination unit 305 may determine to increase the weight of the lifting / unloading operation unit 18 when the height WH of the loading or unloading position is above a predetermined height, and not change the weight of the lifting / unloading operation unit 18 (not increase the weight) when the height WH of the loading or unloading position is below the predetermined height. The predetermined height may be, for example, 1 m from the road surface G.

[0039] Furthermore, the weight determination unit 305 changes the weight of the lifting operation unit 18 according to the degree of inclination of the road surface G and the height WH of the loading or unloading position. As shown in Figure 4, the loading and unloading work position LP is the loading and unloading position in front of the rack R on which the load W is placed. If the road surface G is inclined, the driver H will feel more fear. Therefore, the weight determination unit 305 determines that the greater the inclination of the road surface G and the higher the height WH of the loading or unloading position, the heavier the weight of the lifting operation unit 18 will be.

[0040] More specifically, the weight determination unit 305 determines that the weight of the lifting operation unit 18 will not be changed (remain at the first weight) when the height WH of the loading or unloading position is less than a predetermined height. The weight determination unit 305 also determines that the weight of the lifting operation unit 18 will be increased (to the second weight) when the height WH of the loading or unloading position is equal to or greater than the predetermined height. Furthermore, even if the height WH of the loading or unloading position is less than the predetermined height, the weight of the lifting operation unit 18 will be increased (to the second weight) when the inclination of the road surface G is equal to or greater than a predetermined size. In addition, the weight determination unit 305 determines that the weight will be increased further (to the third weight) when the height WH of the loading or unloading position is equal to or greater than the predetermined height AND the inclination of the road surface G is equal to or greater than a predetermined size.

[0041] When the weight determination unit 305 determines that the weight of the lifting operation unit 18 should be increased, the change notification unit 306 notifies the driver H of the change in weight of the lifting operation unit 18 via voice from the speaker 19. In this way, the change notification unit 306 makes the driver H aware of the change in weight of the lifting operation unit 18.

[0042] The change command unit 307 controls the weight change unit 21 to change the weight of the lifting operation unit 18, in accordance with the determination of the weight determination unit 305. As a result, the weight change system S allows the driver H to perform the lifting operation carefully when the driver's cab 6 is higher than a predetermined height.

[0043] <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.

[0044] (1) First, when the forklift 1 moves to the loading / unloading position LP (see S1 in Figure 5), the weight change system S detects the tilt of the loading / unloading position LP (see S2 in Figure 5).

[0045] (2) The weight change system S obtains the height WH of the loading or unloading position from the storage unit 301 (see S3 in Figure 5), and determines the weight of the lifting operation unit 18 based on the height WH of the loading or unloading position (see S4 in Figure 5). Furthermore, the weight change system S determines the weight of the lifting operation unit 18 based on the height WH of the loading or unloading position and the degree of inclination of the loading / unloading position LP (see S4 in Figure 5).

[0046] (3) Next, when the weight change system S decides to increase the weight of the lifting operation unit 18, it notifies the driver H that the weight of the lifting operation unit 18 will be increased (see S5 in Figure 5), and then increases the weight of the lifting operation unit 18 (see S6 in Figure 5).

[0047] In this way, the weight change system S can prevent sudden lifting or major operational errors by increasing the weight of the lifting operation unit 18 when the loading or unloading position is high, thereby allowing the driver H to perform the lifting operation carefully. Furthermore, the weight change system S can enable quick operation of the lifting operation unit 18 by not increasing its weight when the loading or unloading position is low. In addition, the weight change system S can enable more careful lifting operation by increasing the weight of the lifting operation unit 18 the greater the inclination of the loading position LP, in addition to the height WH of the loading and unloading position.

[0048] 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.

[0049] <Variation> The weight change system S may be configured to change only one of the weights of the lifting operation unit 18, either the lifting or lowering weight. In this case, the weight change unit 21 changes only the weight of either the lifting button or the lowering button.

[0050] The memory unit 301 stores the height WH of the loading or unloading position in the rack R as the number of shelves in the rack R, and the weight determination unit 305 may decide to change the weight of the lifting operation unit 18 when the number of shelves in the rack R at the loading or unloading position is equal to or greater than a predetermined number of shelves. In this case, the weight determination unit 305 may also decide not to change the weight of the lifting operation unit 18 when the number of shelves in the rack R at the loading or unloading position is less than a predetermined number of shelves.

[0051] The memory unit 301 may store the magnitude of the inclination of the road surface G at the loading / unloading position LP. In this case, the weight determination unit 305 changes the weight of the lifting / lowering operation unit 18 according to the inclination of the road surface G stored in the memory unit 301 and the height WH of the loading or unloading position. In this case, the weight change system S does not need to include the inclination detection unit 23.

[0052] The lifting / lowering operation unit 18 is not limited to the buttons described above, but may be composed of a lever or the like. The lifting / lowering operation unit 18 may be composed of a rotatable operating member, such as an accelerator grip 16. In this case, the lifting / lowering operation unit 18 can be switched between raising and lowering depending on the direction of rotation. Furthermore, this lifting / lowering operation unit 18 may have a device that assists the weight when operating it via electronic control. In this case, the weight adjustment unit 21 may be configured to adjust the assist force of the lifting / lowering operation unit 18 via electronic control, for example. As a result, the weight adjustment unit 21 substantially changes the weight of the lifting / lowering operation unit 18 when operated by the driver H.

[0053] Furthermore, for example, the weight adjustment unit 21 may be composed of a device that can adjust the weight of the lifting operation unit 18 by means of a spring. Alternatively, the weight adjustment unit 21 may be configured to change the magnitude of the power of each device that responds to the amount of operation of the lifting operation unit 18, for example, based on a command from the change command unit 307. In this way, the weight adjustment unit 21 substantially changes the weight of the lifting operation unit 18. In these cases, the lifting operation unit 18 may be configured to accelerate or decelerate its lifting and lowering depending on the amount of rotation.

[0054] • 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 lifting operation unit 18 by communicating with this server computer.

[0055] • The forklift 1 may be equipped with a monitor instead of a speaker 19, and the change notification unit 306 may use this monitor to notify that the weight of the lifting operation unit 18 will be changed. [Explanation of symbols]

[0056] S Weight change system C Safety Cable G road surface H Driver LP loading / unloading location R Rack 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 Lifting and lowering control unit 19 speakers 21 Weight change section 23 Tilt detection unit 30 Control Unit 301 Storage section 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 storage unit that stores the height of either or both of the loading and unloading positions, A weight adjustment unit that changes the weight of the lifting operation unit that operates the lifting device, A weight determination unit that determines to increase the weight of the lifting operation unit according to the height of the loading position or the loading position, A weight change system comprising: a change command unit that controls the weight change unit to change the weight of the lifting operation unit according to the determination of the weight determination unit.

2. The weight adjustment system according to claim 1, wherein the weight determination unit determines that the weight of the lifting operation unit becomes heavier when the height of the loading position or the loading position is greater than or equal to a predetermined height.

3. The weight changing system according to claim 1, wherein the weight determination unit determines not to change the weight of the lifting operation unit when the height of the loading position or the loading position is less than a predetermined height.

4. The storage unit stores the height of the loading position or loading position in the rack as the number of shelves in the rack. The weight changing system according to claim 1, wherein the weight determination unit determines that the weight of the lifting operation unit becomes heavier when the number of rack levels at the loading position or loading position in the rack is equal to or greater than a predetermined number of levels.

5. The storage unit stores the height of the loading position or loading position in the rack as the number of shelves in the rack. The weight changing system according to claim 1, wherein the weight determination unit determines not to change the weight of the lifting operation unit when the number of rack levels at the loading position or loading position in the rack is less than a predetermined number of levels.

6. The memory unit further stores the magnitude of the slope of the road surface at the loading / unloading position related to the loading / unloading position, The weight determination unit changes the weight of the lifting operation unit according to claim 1, wherein the weight determination unit changes the weight of the lifting operation unit according to the magnitude of the inclination of the road surface at the loading / unloading position and the height of the loading position or the loading / unloading position.

7. The system further includes a tilt detection unit for detecting the magnitude of the inclination of the road surface at the loading / unloading position related to the loading / unloading position, The weight determination unit changes the weight of the lifting operation unit according to claim 1, wherein the weight determination unit changes the weight of the lifting operation unit according to the magnitude of the inclination of the road surface at the loading / unloading position and the height of the loading position or the loading / unloading position.

8. The weight changing system according to claim 1, further comprising a change notification unit that notifies the operator that the weight of the lifting operation unit will be changed.

9. A forklift comprising a weight changing system according to any one of claims 1 to 8.

10. A program used in a weight change system comprising a weight change unit for changing the weight of the lifting and lowering mechanism of a forklift having a driver's cab, and a computer, On the computer, A weight determination unit that determines how to increase the weight of the lifting operation unit according to the height of the loading or unloading position, A weight change command unit and a weight change program that are executed by controlling the weight change unit to change the weight of the lifting operation unit, according to the determination of the weight determination unit.

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