JP2026000057A - Warning device and forklift equipped with said device - Google Patents

Abstract

[Problem] To provide a warning device that can warn of over-approaching vehicles more appropriately than conventional devices. [Solution] The warning device of the present invention includes a left-side lighting device 30L attached to a forklift 1A that emits light toward the road surface G around the forklift 1A, an illumination direction changing device 31L that can change the direction of illumination from the left-side lighting device 30L, and a control device that issues a command to the illumination direction changing device 31L regarding the illumination direction generated based on the height H of a load B positioned on the forks 22L, 22R of the forklift 1A. (Selected Figure)

Description

The present invention relates to a warning device that prevents people in the vicinity of a forklift from getting too close to the forklift, and to a forklift equipped with such a device.

Conventionally, warning devices are known that prevent people near a forklift from getting too close to the forklift. For example, the warning device described in Non-Patent Document 1 consists of one lighting device each attached to the left and right head guards. The right lighting device projects light toward the road surface to the right of the vehicle body, drawing a warning line at a predetermined position slightly away from the vehicle body. Similarly, the left lighting device projects light toward the road surface to the left of the vehicle body, drawing a warning line at a predetermined position slightly away from the vehicle body. The warning lines allow people near the forklift to recognize the boundary between areas where it is not safe to approach and areas where it is not.

“Safety LED Line Light,” [online], PCS Corporation, [Retrieved May 31, 2024], Internet <URL: https://p-c-s.co.jp/items/led-line-light>

However, the boundary between areas that cannot be safely approached and areas that can be safely approached changes from moment to moment depending on factors such as the nature of the loading and unloading work being carried out. For example, when carrying a load that is prone to collapse, the area that cannot be safely approached becomes wider than when other loads are not being carried. However, the above-mentioned conventional warning devices and forklifts were unable to flexibly change the position of the warning line depending on factors such as the nature of the loading and unloading work.

The present invention was made in consideration of the above circumstances, and its objective is to provide a warning device that can issue a warning about approaching vehicles more appropriately than conventional devices, and a forklift equipped with such a device.

To solve the above problems, the warning device of the present invention is characterized by comprising a lighting device that is attached to a forklift and emits light toward the road surface around the forklift, an illumination direction change device that can change the direction of illumination from the lighting device, and a control device that issues to the illumination direction change device a command regarding the illumination direction generated based on the size or weight of the load positioned on the forks of the forklift.

The control device of the warning device may be configured to generate a command to move the illuminated position farther away from the forklift as the size of the load increases. The size of the load may be the height of the load relative to the road surface, or the height of the load relative to the forks.

The control device of the warning device may be configured to generate a command to move the illuminated position away from the forklift as the load weight increases.

The illumination direction change device of the warning device may change the illumination direction by oscillating the lighting device in accordance with a command.

If the lighting device of the warning device includes multiple lighting devices facing different directions, the illumination direction change device may change the direction of illumination by turning on one of the multiple lighting devices in accordance with a command.

In order to solve the above problems, the forklift according to the present invention comprises a vehicle body including a head guard, and a load handling device consisting of a mast and forks mounted in front of the vehicle body, and is characterized by comprising a lighting device mounted on the mast or head guard that emits linear light parallel to the forks toward the road surface around the forks, an illumination direction changing device that can change the direction of illumination from the lighting device, and a control device that gives the illumination direction changing device a command regarding the illumination direction generated based on the size or weight of the load positioned on the forks.

The forklift control device may be configured to generate a command to move the illuminated position farther away from the forks as the size of the load increases. The size of the load may be the height of the load relative to the road surface, or the height of the load relative to the forks.

The forklift control device may be configured to generate commands that move the illuminated position away from the forks as the load weight increases.

The forklift's illumination direction change device may change the illumination direction by oscillating the lighting device in accordance with a command.

If the forklift's lighting system includes multiple lighting devices facing different directions, the illumination direction change device may change the direction of illumination by turning on one of the multiple lighting devices in accordance with a command.

The present invention provides a warning device that can warn of approaching vehicles more appropriately than conventional devices, and a forklift equipped with the device.

1A and 1B are diagrams showing the appearance of a forklift according to a first embodiment of the present invention, in which FIG. 1A is a side view and FIG. 1B is a plan view. 1 is a block diagram showing a schematic configuration of a forklift and a warning device according to a first embodiment of the present invention; 10 is a graph showing the relationship between load height H and distances DL and DR in the first embodiment of the present invention. 1A and 1B are diagrams showing the appearance of a forklift according to a first embodiment of the present invention, in which (A) is a plan view when the height H of a load is H1, and (B) is a plan view when the height H of a load is H2 (where H2>H1). 10A and 10B are diagrams showing the appearance of a forklift according to a second embodiment of the present invention, in which FIG. 10A is a side view and FIG. FIG. 10 is a block diagram showing a schematic configuration of a forklift and a warning device according to a second embodiment of the present invention. 10 is a graph showing the relationship between load height H and distances DL and DR in a second embodiment of the present invention. 10A and 10B are diagrams showing the appearance of a forklift according to a third embodiment of the present invention, in which (A) is a side view and (B) is a plan view. FIG. 10 is a block diagram showing a schematic configuration of a forklift and a warning device according to a third embodiment of the present invention. 10 is a graph showing the relationship between the load W and the distances DL and DR in the third embodiment of the present invention. 10A and 10B are diagrams showing the appearance of a forklift according to a modified example of the present invention, in which FIG. 10A is a plan view when the size of the load is relatively small, and FIG. 10B is a plan view when the size of the load is relatively large. 10 is a graph showing the relationship between the dimensions or load of a load and the distances DL and DR in a modified example of the present invention. FIG. 10 is a block diagram showing a schematic configuration of a forklift and a warning device according to a modified example of the present invention. 10A and 10B are diagrams showing the appearance of a forklift according to a modified example of the present invention, in which (A) is a plan view in which the warning line is arc-shaped, and (B) is a plan view in which a warning line is also drawn in front.

Hereinafter, an embodiment of a warning device and forklift according to the present invention will be described with reference to the accompanying drawings.

[First Example]
1 shows a forklift 1A according to a first embodiment of the present invention. As shown in the figure, the forklift 1A is a counterbalance type forklift, and includes a vehicle body 10 that travels on a road surface G, and a loading device 20 provided in front of the vehicle body 10.

The cargo handling device 20 includes a mast 21 and a pair of left and right forks 22L, 22R that move up and down along the mast 21. When transporting a load B, the forks 22L, 22R are inserted into a pallet P carrying the load B.

The vehicle body 10 includes a seat 11 on which the operator M sits, an operating device 12 located within reach of the seated operator M's hands and feet, and a head guard 13 that covers the head of the seated operator M. The operating device 12 is composed of a lever for moving the forks 22L, 22R up and down, a lever for tilting the mast 21 forward and backward, and a handle for determining the direction of travel of the forklift 1A. The operating device 12 outputs an operating signal corresponding to the operation of the levers, etc., performed by the operator M to the control device 15A, which will be described later.

The vehicle body 10 further includes a travel device 14 and a control device 15A, which are not shown in FIG. 1. The travel device 14 is composed of a mechanism for changing the direction of the rear wheels (steered wheels), an engine, a transmission, etc. The control device 15A is composed of a microcontroller (MCU, Micro Controller Unit) and associated memory, etc. As shown in FIG. 2, the control device 15A controls the loading device 20 and the travel device 14 in response to operation signals output by the operating device 12.

As shown in Figures 1 and 2, the forklift 1A further includes a left-side lighting device 30L and an associated illumination direction change device 31L, a right-side lighting device 30R and an associated illumination direction change device 31R, and a height detector 16A that detects the height H of a load B relative to the road surface G. In this embodiment, the lighting devices 30L, 30R, illumination direction change devices 31L, 31R, and control device 15A constitute a "warning device."

The left-side lighting device 30L is mounted on the left end of the top of the mast 21 via an illumination direction change device 31L. The left-side lighting device 30L emits a line of red light LL parallel to the fork 22L toward the road surface G around the fork 22L. In other words, the left-side lighting device 30L draws a red warning line IL on the road surface G parallel to the fork 22L.

The illumination direction change device 31L can change the illumination direction of the light LL by pivoting the left-side lighting device 30L mainly in the vertical direction in accordance with commands given by the control device 15A. When the illumination direction change device 31L points the left-side lighting device 30L downward, the distance DL between the vehicle body 10 and the warning line IL in the vehicle width direction decreases. In other words, the warning line IL moves closer to the fork 22L. Conversely, when the illumination direction change device 31L points the left-side lighting device 30L upward, the distance DL between the vehicle body 10 and the warning line IL increases. In other words, the warning line IL moves farther away from the fork 22L.

The right-side lighting device 30R is mounted on the right end of the top of the mast 21 via the illumination direction change device 31R. The right-side lighting device 30R emits a line of red light LR parallel to the fork 22R toward the road surface G around the fork 22R. In other words, the right-side lighting device 30R draws a red warning line IR on the road surface G parallel to the fork 22R.

The irradiation direction change device 31R can change the irradiation direction of the light LR by swinging the right-side lighting device 30R mainly up and down in accordance with commands given by the control device 15A. When the irradiation direction change device 31R points the right-side lighting device 30R downward, the distance DR between the vehicle body 10 and the warning line IR in the vehicle width direction decreases. In other words, the warning line IR moves closer to the fork 22R. Conversely, when the irradiation direction change device 31R points the right-side lighting device 30R upward, the distance DR between the vehicle body 10 and the warning line IR increases. In other words, the warning line IR moves farther away from the fork 22R.

The height detector 16A is an ultrasonic distance sensor located at the top of the mast 21, i.e., at a position where it can look down on the load B. The height detector 16A detects the height H of the load B relative to the road surface G based on the vertical distance from the height detector 16A itself to the load B and the known height of the mast 21. The height detector 16A then outputs a detection signal corresponding to the detected height H to the control device 15A.

The height detector 16A may output a detection signal corresponding to the vertical distance from the height detector 16A itself to the load B. In this case, the control device 15A can determine the height H based on the known height of the mast 21 and the distance indicated by the detection signal.

The control device 15A generates a command to increase the aforementioned distance DL as the height H of the load B increases (see Figure 3). In other words, the control device 15A generates a command to move the position of the warning line IL away from the fork 22L as the height H of the load B increases. The control device 15A then provides the generated command to the irradiation direction change device 31L associated with the left-side lighting device 30L. Specifically, when the height H of the load B is H1, the control device 15A provides a command to the irradiation direction change device 31L to set the distance DL to D1 (see Figure 4(A)). Furthermore, when the height H of the load B is H2 (where H2 > H1), the control device 15A provides a command to the irradiation direction change device 31L to set the distance DL to D2 (where D2 > D1) (see Figure 4(B)).

The control device 15A also generates a similar command for the distance DR. That is, the control device 15A generates a command to increase the distance DR as the height H of the load B increases (see FIG. 3). In other words, the control device 15A generates a command to move the warning line IR farther away from the fork 22R as the height H of the load B increases. The control device 15A then provides the generated command to the irradiation direction change device 31R associated with the right-side lighting device 30R. Specifically, when the height H of the load B is H1, the control device 15A provides a command to the irradiation direction change device 31R to set the distance DR to D1 (see FIG. 4(A)). Furthermore, when the height H of the load B is H2 (where H2 > H1), the control device 15A provides a command to the irradiation direction change device 31R to set the distance DR to D2 (where D2 > D1) (see FIG. 4(B)).

In this way, the warning devices (30L, 30R, 31L, 31R, 15A) and forklift 1A according to this embodiment can provide an appropriate warning (indicating the boundary between areas that cannot be safely approached and areas that can) according to the height H of the load B.

The reason why the distances DL and DR are increased as the height H of the load B increases is that the higher the height H of the load B, the greater the likelihood of the load collapsing, and the wider the impact of the load collapsing. Furthermore, the reason why the distances DL and DR are not increased beyond D2 is that if the warning lines IL and IR are too far away from the forks 22L and 22R, the relationship between the warning lines IL and IR and the forklift 1A becomes weak, making it difficult to convey the meaning of the warning.

[Second Example]
A forklift 1B according to a second embodiment of the present invention is shown in Fig. 5. As shown in Fig. 5 and Fig. 6, the forklift 1B includes a vehicle body 10 (which includes a seat 11, an operating device 12, a head guard 13, a traveling device 14, and a control device 15B), a cargo handling device 20, lighting devices 30L and 30R, irradiation direction change devices 31L and 31R, and a height detector 16B that detects the height H of a load B relative to the forks 22L and 22R. In this embodiment, the lighting devices 30L and 30R, the irradiation direction change devices 31L and 31R, and the control device 15B constitute a "warning device."

The height detector 16B is an ultrasonic distance sensor located at the top of the mast 21, i.e., at a position where it can look down on the load B. The height detector 16B detects the height H of the load B relative to the forks 22L, 22R based on the vertical distance from the height detector 16B itself to the load B, the known height of the mast 21, and the height (lift height) of the forks 22L, 22R. The height detector 16B then outputs a detection signal corresponding to the detected height H to the control device 15B.

The height detector 16B may output a detection signal corresponding to the vertical distance from the height detector 16B itself to the load B. In this case, the control device 15B can determine the height H based on the known height of the mast 21, the lifting height, and the distance indicated by the detection signal.

The control device 15B generates a command to increase the distance DL as the height H of the load B increases (see Figure 7). In other words, the control device 15B generates a command to move the position of the warning line IL away from the fork 22L as the height H of the load B increases. The control device 15B then provides the generated command to the irradiation direction change device 31L associated with the left-side lighting device 30L. Specifically, when the height H of the load B is H1, the control device 15B provides a command to the irradiation direction change device 31L to set the distance DL to D1. Furthermore, when the height H of the load B is H2 (where H2 > H1), the control device 15B provides a command to the irradiation direction change device 31L to set the distance DL to D2 (where D2 > D1).

The control device 15B also generates a similar command for the distance DR. That is, the control device 15B generates a command to increase the distance DR as the height H of the load B increases (see Figure 7). In other words, the control device 15B generates a command to move the position of the warning line IR farther away from the fork 22R as the height H of the load B increases. The control device 15B then provides the generated command to the irradiation direction change device 31R associated with the right-side lighting device 30R. Specifically, when the height H of the load B is H1, the control device 15B provides a command to the irradiation direction change device 31R to set the distance DR to D1. Furthermore, when the height H of the load B is H2 (where H2 > H1), the control device 15B provides a command to the irradiation direction change device 31R to set the distance DR to D2 (where D2 > D1).

In this way, the warning devices (30L, 30R, 31L, 31R, 15B) and forklift 1B according to this embodiment can provide an appropriate warning (indicating the boundary between areas that cannot be safely approached and areas that can) based on the height H of the load B relative to the forks 22L and 22R.

[Third Example]
A forklift 1C according to a third embodiment of the present invention is shown in Figure 8. As shown in Figure 8 and Figure 9, the forklift 1C includes a vehicle body 10 (which includes a seat 11, an operating device 12, a head guard 13, a traveling device 14, and a control device 15C), a loading device 20, lighting devices 30L and 30R, irradiation direction change devices 31L and 31R, and a load detector 17 that detects the weight (load W) of a load B on the forks 22L and 22R. In this embodiment, the lighting devices 30L and 30R, the irradiation direction change devices 31L and 31R, and the control device 15C constitute a "warning device."

The load detector 17 is a sensor installed in an appropriate location on the loading device 20. The load detector 17 outputs a detection signal corresponding to the detected load W to the control device 15C.

The control device 15C generates a command to increase the distance DL as the load W increases (see Figure 10). In other words, the control device 15C generates a command to move the position of the warning line IL away from the fork 22L as the load W increases. The control device 15C then provides the generated command to the illumination direction change device 31L associated with the left-side lighting device 30L. Specifically, when the load W is W1, the control device 15C provides a command to the illumination direction change device 31L to set the distance DL to D1. Furthermore, when the load W is W2 (where W2 > W1), the control device 15C provides a command to the illumination direction change device 31L to set the distance DL to D2 (where D2 > D1).

The control device 15C also generates a similar command for the distance DR. That is, the control device 15C generates a command to increase the distance DR as the load W increases (see Figure 10). In other words, the control device 15C generates a command to move the position of the warning line IR away from the fork 22R as the load W increases. The control device 15C then provides the generated command to the irradiation direction change device 31R associated with the right-side lighting device 30R. Specifically, when the load W is W1, the control device 15C provides a command to the irradiation direction change device 31R to set the distance DR to D1. Furthermore, when the load W is W2 (where W2 > W1), the control device 15C provides a command to the irradiation direction change device 31R to set the distance DR to D2 (where D2 > D1).

In this way, the warning devices (30L, 30R, 31L, 31R, 15C) and forklift 1C according to this embodiment can provide an appropriate warning (indicating the boundary between areas that cannot be safely approached and areas that can be safely approached) according to the load W.

The reason why the distances DL and DR are increased as the load W increases is that the greater the load W, the greater the impact on the surrounding area if the load collapses.

[Modification]
Although the warning device and the forklift according to the present invention have been described above as examples, the present invention is not limited to these.

For example, the forklift (warning device) according to the present invention may vary the distances DL and DR in the same manner as in the first embodiment, etc., depending on the fore-and-aft dimension BFR or the left-and-right dimension BLR of the load B, as in the forklift 1D shown in Figure 11.

The forklift (warning device) according to the present invention may also change the distances DL and DR in a stepped manner depending on the dimensions (height H, front-to-rear dimension BFR or left-to-right dimension BLR) or load of the load B (see Figure 12(A)), or may change the distance DL in a stepped manner while changing the distance DR linearly depending on the dimensions or load of the load B (see Figure 12(B)).

As shown in FIG. 13, the forklift (warning device) according to the present invention may also include a control device 15E, m (where m is an integer of 2 or greater) left-side lighting devices 30L-1, 30L-2, ..., 30L-m facing in different directions, n (where n is an integer of 2 or greater) right-side lighting devices 30R-1, 30R-2, ..., 30R-n facing in different directions, and an illumination direction change device 31. In accordance with a command generated by the control device 15E based on the dimensions or load of load B, the illumination direction change device 31 turns on one of the left-side lighting devices 30L-1, 30L-2, ..., 30L-m and one of the right-side lighting devices 30R-1, 30R-2, ..., 30R-n, and turns off the other lighting devices. This allows the control device 15E and the illumination direction change device 31 to move the warning lines IL and IR closer or farther apart depending on the dimensions or load of load B.

Furthermore, the forklift (warning device) according to the present invention may be equipped with lighting devices 30L', 30R' that draw arc-shaped warning lines IL', IR' on the road surface G by emitting light LL', LR', as in the forklift 1F shown in Figure 14 (A).

The forklift (warning device) according to the present invention may further include a central lighting device 30C that draws a warning line IC on the road surface G ahead by emitting light LC, as in the forklift 1G shown in Figure 14(B). In this case, it is preferable that the control device of the forklift 1G move the warning line IC closer or farther away in a manner similar to that used to move the warning lines IL and IR closer or farther away.

Furthermore, height detectors 16A and 16B are not limited to ultrasonic distance sensors. For example, height detectors 16A and 16B may detect height H by analyzing image data acquired by a camera.

Furthermore, the present invention does not limit the method for detecting the dimensions BFR and BLR of load B.

1A, 1B, 1C, 1D, 1F, 1G Forklift 10 Vehicle body 11 Seat 12 Operating device 13 Head guard 14 Traveling device 15A, 15B, 15C, 15E Control device 16A, 16B Height detector 17 Load detector 20 Load handling device 21 Mast 22L, 22R Fork 30C Center lighting device 30L Left side lighting device 30R Right side lighting devices 31, 31L, 31R Illumination direction changing devices IC, IL, IR Warning line

Claims (14)

a lighting device attached to the forklift to irradiate light onto a road surface around the forklift;
an illumination direction changing device capable of changing the direction of illumination by the lighting device;
a control device that gives to the irradiation direction changing device a command regarding the direction of irradiation generated based on the size or weight of a load placed on the forks of the forklift. 2. The warning device according to claim 1, wherein the control device generates the command such that the position of the light to be emitted moves farther away from the forklift as the size of the load increases. 3. The warning device according to claim 2, wherein the dimension of the load is a height of the load relative to the road surface. 3. The warning device of claim 2, wherein the dimension of the load is the height of the load relative to the fork. 2. The warning device according to claim 1, wherein the control device generates the command such that the position of the light to be emitted moves away from the forklift as the weight of the load increases. 6. The warning device according to claim 1, wherein the illumination direction changing device oscillates the lighting device in accordance with the command. the lighting device includes a plurality of lighting devices facing in different directions;
6. The warning device according to claim 1, wherein the illumination direction changing device turns on any one of the plurality of lighting devices in accordance with the command. A forklift truck comprising a vehicle body including a head guard and a cargo handling device consisting of a mast and forks provided in front of the vehicle body,
a lighting device provided on the mast or the head guard, which irradiates a line of light parallel to the fork toward a road surface around the fork;
an illumination direction changing device capable of changing the direction of illumination by the lighting device;
a control device that gives to the irradiation direction changing device a command regarding the direction of irradiation generated based on the size or weight of a load placed on the forks. 9. The forklift according to claim 8, wherein the control device generates the command such that the irradiation position moves farther away from the forks as the size of the load increases. 10. The forklift according to claim 9, wherein the dimension of the load is the height of the load relative to the road surface. 10. The forklift according to claim 9, wherein the dimension of the load is the height of the load relative to the forks. 9. The forklift according to claim 8, wherein the control device generates the command such that the irradiated position moves away from the forks as the weight of the load increases. The forklift according to any one of claims 8 to 12, wherein the illumination direction changing device oscillates the lighting device in accordance with the command. the lighting device includes a plurality of lighting devices facing in different directions;
The forklift according to any one of claims 8 to 12, wherein the illumination direction changing device turns on any one of the plurality of lighting devices in accordance with the command.