JP2026002014A - Forklifts and warning devices - Google Patents

Abstract

A forklift and a warning device are provided that enable an operator to intuitively understand that an undesirable event may occur due to the operation of a loading/unloading operation unit.
[Solution] The forklift 1 is equipped with a cargo handling operation unit 12 operated by an operator M to operate the forks 14, an illumination unit 17 that illuminates the cargo handling operation unit 12 with visible light, and a control unit that controls the illumination unit 17 so that the cargo handling operation unit 12 is illuminated while the cargo handling operation unit 12 is being operated when certain conditions are met.
[Selected Figure] Figure 1

Description

The present invention relates to a forklift equipped with a load-handling control unit operated by an operator to operate the forks, and a warning device.

Generally, forklifts operated by an operator are equipped with a cargo handling operation unit consisting of control levers such as a lift lever and a tilt lever (see, for example, Patent Document 1). The forks that handle cargo are configured to rise and fall in conjunction with the operation of the lift lever, and to tilt in conjunction with the operation of the tilt lever.

Patent No. 7481081

However, for example, if the lift lever is operated to raise the forks while they are tilted forward, the mast and forks may tilt further forward as the mast extends and the forks rise, which could cause the cargo supported by the forks to fall (i.e., the cargo may collapse). When such an undesirable event could occur, it is conceivable to display a warning message on the display or sound a warning buzzer to alert the operator to the operation of the cargo handling control unit.

However, with a configuration in which a warning message is displayed on a display, the operator must shift their gaze to the display to read the warning message. Furthermore, with a configuration in which a warning sound is emitted by a buzzer, there is a risk that the operator may not notice the warning sound if it is difficult to hear due to surrounding noise or hearing impairment, etc. Therefore, there is a problem in that the operator cannot intuitively grasp that an undesirable event may occur as a result of operating the loading and unloading operation unit.

The present invention was made in consideration of the above circumstances, and aims to provide a forklift and warning device that allows the operator to intuitively understand that an undesirable event may occur due to the operation of the loading and unloading control unit.

To solve the above problems, the forklift of the present invention is characterized by comprising a load handling operation unit operated by an operator to operate the forks, an illumination unit capable of illuminating the load handling operation unit with visible light, and a control unit that controls the illumination unit so that the load handling operation unit is illuminated while it is being operated when certain conditions are met.

The forklift truck also preferably includes a tilt sensor for detecting a forward tilt state in which the forks tilt downward as they move forward toward the tips of the forks, and a load sensor for detecting a cargo support state in which the forks are supporting cargo. The cargo handling operation unit includes a lift lever for moving the forks in the vertical direction. The control unit preferably defines the specific condition as the tilt sensor detecting the forward tilt state and the load sensor detecting the cargo support state, and when the specific condition is met, controls the illumination unit to illuminate the lift lever while the lift lever is being operated to move the forks upward.

The forklift truck further includes a lift sensor for detecting a high-lift state in which the lift height of the forks exceeds a predetermined lift height, and a load sensor for detecting a cargo-support state in which the forks are supporting cargo. The cargo handling operation unit includes a tilt lever for tilting the forks in the forward and backward directions. The control unit preferably defines the specific condition as the high-lift state being detected by the lift sensor and the cargo-support state being detected by the load sensor, and when the specific condition is met, controls the illumination unit so that the tilt lever is illuminated while the tilt lever is being operated to tilt the forks forward.

The forklift truck preferably further includes a lift sensor that detects the height of the forks and a tilt sensor that detects the tilt of the forks in the fore-and-aft direction, and the specific conditions preferably include a condition related to the height of the forks detected by the lift sensor or a condition related to the tilt of the forks in the fore-and-aft direction detected by the tilt sensor.

Furthermore, it is preferable that the cargo handling operation unit includes a lift lever for moving the forks up and down and a tilt lever for tilting the forks back and forth, and that the illumination unit is configured to be able to illuminate the lift lever and tilt lever with visible light individually.

In order to solve the above-mentioned problems, the warning device of the present invention is characterized by comprising an illumination unit capable of emitting visible light to a cargo handling operation unit operated by an operator to operate the forks of a forklift, and a control unit that controls the illumination unit so that the cargo handling operation unit is illuminated while it is being operated when certain conditions are met.

The present invention provides a forklift and warning device that allows the operator to intuitively understand that an undesirable event may occur due to the operation of the loading and unloading control unit.

1A and 1B are external views of a forklift according to an embodiment of the present invention, in which FIG. 1A is a left side view and FIG. 1B is a plan view. FIG. 2 is a block diagram showing a schematic configuration of the forklift according to the embodiment. 10 is a flowchart showing a control flow of an irradiation unit.

As shown in FIG. 1, the forklift 1 according to this embodiment is a counterbalance forklift and includes a riding section 11, a load handling operation section 12, a head guard 13, forks 14, a lift device 15, a tilt device 16, and an illumination unit 17. The illumination unit 17 constitutes the warning device of the present invention that is mounted on the forklift 1.

The riding section 11 consists of a driver's seat where the operator M sits. A loading/unloading operation section 12 is provided in front of the riding section 11 and is operated by the operator to operate the forks 14. A head guard 13 is provided above the riding section 11 to protect the operator M.

The cargo handling operation unit 12 includes a lift lever 12A for moving the forks 14 in the up-down direction Z and a tilt lever 12B for tilting the forks 14 in the forward-backward direction X. When the lift lever 12A is tilted in one predetermined direction, the lift device 15 moves the forks 14 upward, and when the lift lever 12A is tilted in the other direction, the lift device 15 moves the forks 14 downward. When the tilt lever 12B is tilted in one predetermined direction, the tilt device 16 tilts the forks 14 forward, and when the tilt lever 12B is tilted in the other direction, the tilt device 16 tilts the forks 14 backward. Each lever 12A, 12B is configured to return to its neutral position when the operator M releases their hands from the lever 12A, 12B.

The head guard 13 is made of a lattice material that covers the operator M from above. The head guard 13 is provided with an illumination unit 17 that illuminates the cargo handling operation unit 12 from above.

The fork 14 extends in the front-to-rear direction X and consists of two claws spaced apart in the left-to-right direction Y. The fork 14 directly supports cargo (not shown) by being inserted into the cargo, or indirectly supports the cargo by being inserted into a pallet (not shown) that supports the cargo. The fork 14 is attached to a lift bracket 15B that constitutes the lift device 15.

The lift device 15 moves the forks 14 in the vertical direction Z (i.e., raises and lowers them). The lift device 15 is composed of a mast 15A that can be extended and retracted in the vertical direction Z, a lift bracket 15B that can be raised and lowered along the mast 15A, and a lift cylinder (not shown) attached to the mast 15A. By operating the lift cylinder, the lift device 15 extends the mast 15A and raises the lift bracket 15B, moving the forks 14 upward (i.e., raising them). The lift device 15 also retracts the mast 15A and lowers the lift bracket 15B, moving the forks 14 downward (i.e., lowering them).

The tilt device 16 tilts the forks 14 in the fore-and-aft direction X (i.e., tilts them forward and backward). The tilt device 16 is composed of a tilt cylinder 16A connected to the mast 15A. By operating the tilt cylinder 16A, the tilt device 16 tilts the upper part of the mast 15A forward, causing the forks 14 to tilt forward (i.e., tilt forward). The tilt device 16 also tilts the upper part of the mast 15A backward, causing the forks 14 to tilt backward (i.e., tilt backward).

The illumination unit 17 is composed of an LED floodlight capable of emitting visible light toward the cargo handling operation unit 12. When the illumination unit 17 emits visible light toward the cargo handling operation unit 12, at least a portion of the cargo handling operation unit 12 and the vicinity of that portion are illuminated with visible light. The illumination unit 17 preferably emits visible light in a color (e.g., red) that is easily noticeable by the operator M. The illumination unit 17 is configured to be able to emit visible light individually toward each of the lift lever 12A and tilt lever 12B by changing the direction of emission of the visible light.

As shown in FIG. 2, the forklift 1 according to this embodiment further includes a lift sensor 21, a tilt sensor 22, a load sensor 23, and a control unit 24. The control unit 24 constitutes the warning device of the present invention that is installed on the forklift 1.

The lift sensor 21 is a sensor for detecting a high lift state in which the lift height of the forks 14 exceeds a predetermined lift height, and detects the lift height of the forks 14 (i.e., their position in the vertical direction Z) by acquiring operation information from the lift device 15. The lift sensor 21 outputs a signal indicating the lift height detection result to the control unit 24.

The tilt sensor 22 is a sensor for detecting a forward tilt state in which the forks 14 tilt downward as they move forward toward the tips of the forks 14. By acquiring operation information from the tilt device 16, the tilt sensor 22 detects the tilt of the forks 14 in the fore-and-aft direction X. The tilt sensor 22 outputs a signal indicating the tilt detection result to the control unit 24.

The load sensor 23 is a sensor for detecting the load support state in which the forks 14 are supporting a load, and detects the load acting on the forks 14. The load sensor 23 outputs a signal indicating the load detection result to the control unit 24.

When specific conditions are met, the control unit 24 controls the illumination unit 17 so that the loading/unloading operation unit 12 is illuminated while the loading/unloading operation unit 12 is being operated. The specific conditions include a condition related to the lift height of the forks 14 detected by the lift sensor 21, or a condition related to the tilt of the forks 14 in the fore-and-aft direction X detected by the tilt sensor 22.

Specifically, the control unit 24 determines that specific condition 1 is met when the tilt sensor 22 detects a forward tilt state and the load sensor 23 detects a load-supporting state, and when this specific condition 1 is met, it controls the illumination unit 17 so that the lift lever 12A is illuminated while the lift lever 12A is being operated to move the fork 14 upward.

Furthermore, the control unit 24 determines that specific condition 2 is met when the lift sensor 21 detects a high-lift state and the load sensor 23 detects a load-supporting state, and when this specific condition 2 is met, controls the illumination unit 17 so that the tilt lever 12B is illuminated while the tilt lever 12B is being operated to tilt the fork 14 forward.

The flow of control of the irradiating unit 17 by the control unit 24 will be described with reference to FIG.
First, the control unit 24 determines whether or not a specific condition is satisfied (step S1). Specifically, the control unit 24 determines in step S1 whether or not the above-mentioned specific condition 1 or specific condition 2 is satisfied based on the outputs of the sensors 21 to 23.

When the control unit 24 determines that the specific condition is not met (step S1: NO), the possibility of cargo collapse is low or nonexistent, so it does not control the illumination unit 17 to illuminate the cargo handling operation unit 12.

On the other hand, when the control unit 24 determines that a specific condition is met (step S1: YES), it determines whether a specific operation has been performed based on the output of the loading/unloading operation unit 12 (step S2).

Specifically, when the control unit 24 determines in step S1 that specific condition 1 is satisfied, it determines in step S2 whether the following specific operation 1 has been performed based on the output of the lift lever 12A.
Specific operation 1: Operation of the lift lever 12A to move the fork 14 upward

Furthermore, when the control unit 24 determines in step S1 that specific condition 2 is satisfied, it determines in step S2 based on the output of the tilt lever 12B whether or not the following specific operation 2 has been performed.
Specific operation 2: Operation of the tilt lever 12B to tilt the fork 14 forward

When the control unit 24 determines that a specific operation has not been performed (step S2: NO), the control unit 24 does not control the illumination unit 17 to illuminate the cargo handling operation unit 12, because the operator M has not performed an operation on the cargo handling operation unit 12 that would cause cargo to collapse.

On the other hand, when the control unit 24 determines that a specific operation has been performed (step S2: YES), because operator M is operating the cargo handling operation unit 12 in a way that causes cargo to collapse, the control unit 24 controls the illumination unit 17 to start illuminating the cargo handling operation unit 12 (step S3). At this time, if the control unit 24 determines in step S2 that specific operation 1 has been performed, it controls the illumination unit 17 to illuminate the lift lever 12A with visible light, and if the control unit 24 determines in step S2 that specific operation 2 has been performed, it controls the illumination unit 17 to illuminate the tilt lever 12B with visible light.

While the illumination unit 17 is illuminating the cargo handling operation unit 12, the control unit 24 determines whether the specific operation has ceased to be performed (step S4). In other words, the control unit 24 determines whether the specific operation determined to have been performed in step S2 has ceased to be performed after the cargo handling operation unit 12 has been illuminated.

When the control unit 24 determines that a specific operation has been performed (step S4: NO), because the operator M continues to operate the cargo handling operation unit 12 in a way that causes cargo to collapse, the control unit 24 does not control the irradiation unit 17 to stop irradiation, but instead maintains the irradiation of the cargo handling operation unit 12.

On the other hand, when the control unit 24 determines that the specific operation has ceased (step S4: YES), since the operator M is not operating the cargo handling operation unit 12 in a way that would cause cargo to collapse, the control unit 24 controls the illumination unit 17 to stop illuminating the cargo handling operation unit 12 (step S5).

In this embodiment, the following effects are obtained.
(1) The forklift 1 includes an illumination unit 17 that can illuminate the load handling operation unit 12 with visible light, and a control unit 24 that controls the illumination unit 17 so that the load handling operation unit 12 is illuminated while the load handling operation unit 12 is being operated when a specific condition is met. With this configuration, the operator M can intuitively understand by seeing the illuminated load handling operation unit 12 that the forklift 1 is in an unusual state and that the load handling operation unit 12 should not be operated. Therefore, the operator M can intuitively understand that an undesirable event, such as a load falling from the forks 14, may occur due to the operation of the load handling operation unit 12.

(2) When the above-mentioned specific condition 1 is satisfied, the control unit 24 controls the illumination unit 17 so that the lift lever 12A is illuminated while the lift lever 12A is being operated to move the forks 14 upward. This configuration allows the operator M to intuitively understand that an undesirable event may occur due to the operation of the lift lever 12A.

(3) When the above-mentioned specific condition 2 is satisfied, the control unit 24 controls the illumination unit 17 so that the tilt lever 12B is illuminated while the tilt lever 12B is being operated to tilt the fork 14 forward. This configuration allows the operator M to intuitively understand that an undesirable event may occur due to the operation of the tilt lever 12B.

(4) The above-mentioned specific conditions include a condition related to the height of the forks 14 detected by the lift sensor 21 or a condition related to the tilt of the forks 14 in the fore-and-aft direction X detected by the tilt sensor 22. With this configuration, situations in which there is a risk of cargo falling from the forks 14 can be specified by the height of the forks 14 or the tilt of the fore-and-aft direction X.

(5) The illumination unit 17 is configured to be able to illuminate the lift lever 12A and the tilt lever 12B individually with visible light. With this configuration, by illuminating only one of the lift lever 12A and the tilt lever 12B with visible light, the operator M can intuitively understand that the lift lever 12A and the tilt lever 12B that are currently being operated should not be operated.

The present invention is not limited to the above embodiment, and the above configuration can be modified. For example, the following modifications can be made, or the following modifications can be combined to make the present invention.

- The configuration of the illuminating unit 17 may be modified as appropriate. For example, the illuminating unit 17 may be provided somewhere other than the head guard 13. Furthermore, the illuminating unit 17 may be configured to simultaneously irradiate both the lift lever 12A and the tilt lever 12B with visible light.

Alternatively, the illumination unit 17 may be configured with multiple LED floodlights, with one LED floodlight configured to illuminate the lift lever 12A with visible light and another LED floodlight configured to illuminate the tilt lever 12B with visible light. In this case, it is possible to illuminate the lift lever 12A and the tilt lever 12B with visible light individually, or to illuminate both the lift lever 12A and the tilt lever 12B with visible light simultaneously.

- The control unit 24 may determine whether the above-mentioned specific operation 1 has been performed based on the operation information of the lift device 15, rather than the output of the lift lever 12A. Furthermore, the control unit 24 may determine whether the above-mentioned specific operation 2 has been performed based on the operation information of the tilt device 16, rather than the output of the tilt lever 12B.

- The cargo handling operation unit may include levers other than the lift lever 12A and tilt lever 12B, and the specific conditions and specific operations described in the above embodiment may be modified as appropriate. That is, for example, if the forklift is a reach forklift, the cargo handling operation unit may include a reach lever for moving the forks in the forward and backward directions. In this case, the forklift may be equipped with a reach sensor that detects the forward and backward positions of the forks, and the above specific conditions may include a condition related to the forward and backward positions of the forks detected by the reach sensor. The above specific conditions may also include a condition related to the traveling speed of the forklift detected by a vehicle speed sensor.

- The manner in which visible light is emitted by the illuminating unit 17 may be changed as appropriate. For example, the illuminating unit 17 may emit visible light intermittently. In other words, the control unit may cause the illuminating unit 17 to blink while maintaining illumination of the loading/unloading operation unit 12.

- In addition to illuminating the cargo handling operation unit 12 with the illumination unit 17, a warning message may be displayed on a display (not shown) equipped on the forklift, or a warning sound may be emitted from a buzzer (not shown) equipped on the forklift.

REFERENCE SIGNS LIST 1 Forklift 12 Load handling operation unit 12A Lift lever 12B Tilt lever 14 Fork 17 Illumination unit 21 Lift sensor 22 Tilt sensor 23 Load sensor 24 Control unit M Operator X Forward/backward direction Y Left/right direction Z Up/down direction

Claims (6)

a cargo handling operation unit operated by an operator to operate the forks;
an irradiation unit capable of irradiating the cargo handling operation unit with visible light;
a control unit that controls the illumination unit so that the cargo handling operation unit is illuminated while the cargo handling operation unit is being operated when a specific condition is satisfied. a tilt sensor for detecting a forward tilt state in which the fork is tilted downward as it moves forward toward the tip of the fork;
a load sensor for detecting a load support state in which the forks are supporting a load,
The cargo handling operation unit includes a lift lever for moving the fork in a vertical direction,
2. The forklift according to claim 1, wherein the control unit determines that the specific condition is that the tilt sensor detects the forward tilt state and that the load sensor detects the load supporting state, and when the specific condition is satisfied, controls the illumination unit to illuminate the lift lever while the lift lever is being operated to move the forks upward. a lift sensor for detecting a high lift state in which the lift height of the forks exceeds a predetermined lift height;
a load sensor for detecting a load support state in which the forks are supporting a load,
The cargo handling operation unit includes a tilt lever for tilting the fork in a forward and backward direction,
2. The forklift according to claim 1, wherein the control unit determines that the specific condition is that the lift sensor detects the high-lift state and that the load sensor detects the load-supporting state, and when the specific condition is satisfied, controls the illumination unit so that the tilt lever is illuminated while the tilt lever is operated to tilt the forks forward. a lift sensor that detects the lift height of the forks;
A tilt sensor that detects the tilt of the fork in the front-rear direction,
2. The forklift according to claim 1, wherein the specific conditions include a condition regarding a lift height of the forks detected by the lift sensor or a condition regarding a tilt angle of the forks in the front-to-rear direction detected by the tilt sensor. The cargo handling operation unit includes a lift lever for moving the forks in a vertical direction and a tilt lever for tilting the forks in a front-rear direction,
The forklift according to claim 1, wherein the illuminating unit is configured to be able to irradiate the lift lever and the tilt lever with visible light individually. an irradiation unit capable of irradiating visible light onto a cargo handling operation unit operated by an operator to operate forks provided on the forklift;
a control unit that controls the illumination unit so that the cargo handling operation unit is illuminated while the cargo handling operation unit is being operated when a specific condition is satisfied.