Warning device and forklift having the same

Abstract

To provide a warning device capable of preventing a load collapse caused by an excessively high load.SOLUTION: A warning device according to the present invention is a device provided in a forklift 1A including a main body 10 having a driver's seat 11 and a fork 22L and a 22R provided in front of the main body 10, and includes lighting devices 30L and 30R that emit light LL and LR from the driver's seat 11 side toward a space on the fork 22L and the 22R that can be occupied by a cargo B to be handled, and a control device that controls lighting states of the lighting devices 22L and 22R based on a height H of the cargo B on the fork and the. 30L 30R. When the height H of the cargo B on the fork 22L and 22R exceeds a predetermined value, the control device switches the lighting state from off to on or on and off.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a warning device that warns an operator that a load placed on the forks is in a dangerous state, and to a forklift equipped with the device. [Background technology]

[0002] Various forklifts have been known in the past that are equipped with a function to notify the operator when a load placed on the forks is in a dangerous state. For example, a forklift described in Patent Document 1 is configured to determine whether a load placed on the forks is misaligned in the horizontal direction, and if it is determined that a load is misaligned, to notify the operator of the abnormality using an alarm device. This configuration can prevent the load from falling over. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-230903 Summary of the Invention [Problem to be solved by the invention]

[0004] However, whether or not a load will collapse is also greatly affected by factors other than the horizontal positional deviation of the load, such as the height of the load. However, to the applicant's knowledge, there has not been a warning device or forklift that can clearly notify the operator that the load is too high.

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a warning device that can prevent a load from falling over due to the load being too high, and a forklift equipped with the warning device. [Means for solving the problem]

[0006] In order to solve the above problems, the warning device of the present invention is provided on a forklift having a vehicle body with a driver's seat and forks provided in front of the vehicle body, and includes a lighting device that emits light from the driver's seat side toward the space above the forks that may be occupied by the load to be handled, and a control device that controls the lighting state of the lighting device based on the height of the load on the forks, and the control device is configured to switch the lighting state from off to on or flashing when the height of the load on the forks exceeds a predetermined threshold.

[0007] The height of the load may be measured based on the road surface or based on the forks.

[0008] In the latter case, it is preferable that the warning device of the present invention further comprises an illumination direction changing device that can change the direction of illumination by the lighting device, and that the control device sends an illumination direction command to the illumination direction changing device corresponding to the height of the fork.

[0009] In order to solve the above problems, the forklift according to the present invention comprises a vehicle body having a driver's seat and forks provided in front of the vehicle body, and is equipped with a lighting device that emits light from the driver's seat side toward the space above the forks that may be occupied by the load to be handled, and a control device that controls the lighting state of the lighting device based on the height of the load on the forks, and the control device is configured to switch the lighting state from off to on or flashing when the height of the load on the forks exceeds a predetermined threshold.

[0010] The height of the load may be measured based on the road surface or based on the forks.

[0011] In the latter case, it is preferable that the forklift according to the present invention further comprises an illumination direction changing device capable of changing the direction of illumination by the lighting device, and that the control device sends an illumination direction command to the illumination direction changing device corresponding to the height of the fork. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a warning device that can prevent load collapse caused by the load height being too high, and a forklift equipped with the device.

Brief Description of the Drawings

[0013] [Figure 1] It is a view showing the appearance of a forklift according to a first embodiment of the present invention, where (A) is a side view and (B) is a plan view. [Figure 2] It is a block diagram showing a schematic configuration of a forklift and a warning device according to a first embodiment of the present invention. [Figure 3] It is a graph showing the relationship between the load height and the lighting state of the lighting device in the first embodiment of the present invention. [Figure 4] It is a view showing the appearance of a forklift according to a second embodiment of the present invention, where (A) is a side view and (B) is a plan view. [Figure 5] It is a block diagram showing a schematic configuration of a forklift and a warning device according to a second embodiment of the present invention. [Figure 6] It is a graph showing the relationship between the load height and the lighting state of the lighting device in the second embodiment of the present invention. [Figure 7] It is a view showing the control by the control device in the second embodiment of the present invention, where (A) is a view showing the control when the lift height is low and the load height H > Hth2, (B) is a view showing the control when the lift height is high and the load height H > Hth2, (C) is a view showing the control when the lift height is low and the load height H < Hth2, and (D) is a view showing the control when the lift height is high and the load height H < Hth2. [Figure 8] It is a view showing a modification of the control by the control device in the first and second embodiments of the present invention, where (A) is a view showing the first modification and (B) is a view showing the second modification. S

Modes for Carrying Out the Invention

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a warning device and a forklift according to the present invention will be described with reference to the accompanying drawings.

[0015] [First Example] A forklift 1A according to a first embodiment of the present invention is shown in Figure 1. 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 cargo handling device 20 provided in front of the vehicle body 10.

[0016] 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 to be handled, the forks 22L, 22R are inserted into a pallet P on which the load B is placed.

[0017] The vehicle body 10 includes a driver's seat 11 where the operator M sits, an operating device 12 provided within reach of the 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, a handle for determining the direction of travel of the forklift 1A, etc. The operating device 12 outputs an operating signal corresponding to the operation of the levers, etc., performed by the operator M to a control device 15A, which will be described later.

[0018] The vehicle body 10 further includes a traveling device 14 and a control device 15A, which are not shown in Fig. 1. The traveling 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 cargo handling device 20 and the traveling device 14 in response to an operation signal output from the operation device 12.

[0019] 1 and 2, the forklift 1A further includes a left lighting device 30L, a right lighting device 30R, and a height detector 16A that detects the height H of a load B relative to a road surface G. In this embodiment, the lighting devices 30L and 30R and the control device 15A constitute a "warning device."

[0020] The left-side lighting device 30L is mounted on the left side wall of the mast 21 (more specifically, the outer mast) via an appropriate bracket 31L. The left-side lighting device 30L emits red light LL from the vehicle body 10 side where the driver's seat 11 is located, toward the space above the forks 22L, 22R, i.e., the space that could be occupied by a load B placed on the forks 22L, 22R. In this embodiment, the left-side lighting device 30L is mounted at a height Hth1 above the road surface G of the mast 21, and emits light LL horizontally. If the height H of the load B relative to the road surface G exceeds Hth1, the light LL emitted from the left-side lighting device 30L will naturally illuminate the load B.

[0021] The right-side lighting device 30R is mounted on the right side wall of the mast 21 (more specifically, the outer mast) via an appropriate bracket 31R. The right-side lighting device 30R emits red light LR from the vehicle body 10 side where the driver's seat 11 is located toward the space above the forks 22L and 22R. In this embodiment, the right-side lighting device 30R is mounted at a height Hth1 from the road surface G of the mast 21, and emits light LR horizontally. Naturally, if the height H of the load B relative to the road surface G exceeds Hth1, the light LR emitted from the right-side lighting device 30R will illuminate the load B. In other words, if the height H of the load B exceeds Hth1, the light LL and LR emitted from the two lighting devices 30L and 30R will illuminate the load B.

[0022] The height detector 16A is an ultrasonic distance sensor installed 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.

[0023] The height detector 16A may output a detection signal corresponding to the height 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.

[0024] The control device 15A controls the lighting state of the lighting devices 30L, 30R based on the height H of the load B. More specifically, as shown in Fig. 3, when the height H of the load B does not exceed the aforementioned Hth1 (hereinafter referred to as the "threshold"), the control device 15A sets the lighting state of the lighting devices 30L, 30R to "off," and when the height H of the load B exceeds the threshold Hth1, the control device 15A sets the lighting state of the lighting devices 30L, 30R to "on."

[0025] The threshold value Hth1 is set near the upper limit of the height at which it is thought that the load B will hardly collapse or tip over.

[0026] As described above, in the warning device (30L, 30R, 15A) and forklift 1A according to this embodiment, when a load B is present on forks 22L, 22R and its height H exceeds threshold value Hth1, the lighting devices 30L, 30R are turned on, illuminating load B. Also, in the warning device (30L, 30R, 15A) and forklift 1A according to this embodiment, the lighting devices 30L, 30R emit lights LL, LR from the vehicle body 10 side where the driver's seat 11 is located. Therefore, the warning device (30L, 30R, 15A) and forklift 1A according to this embodiment can easily notify the operator M seated in the driver's seat 11 that the height H of load B is too high, i.e., the extent to which the height H of load B exceeds threshold value Hth1.

[0027] [Second Example] Fig. 4 shows a forklift 1B according to a second embodiment of the present invention. As shown in Fig. 4 and Fig. 5, the forklift 1B includes a vehicle body 10 (which includes a driver's seat 11, an operating device 12, a head guard 13, a traveling device 14, and a control device 15B), a loading / unloading device 20, lighting devices 30L and 30R, irradiation direction change devices 32L and 32R, 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 32L and 32R, and the control device 15B constitute a "warning device."

[0028] The left-side lighting device 30L is provided on the left side wall of the mast 21 (more specifically, the outer mast) via a left-side illumination direction change device 32L. As in the first embodiment, the left-side lighting device 30L emits red light LL from the vehicle body 10 side toward the space above the forks 22L, 22R, i.e., the space that may be occupied by a load B placed on the forks 22L, 22R. In this embodiment, the left-side lighting device 30L is provided at a height Hth2 from the forks 22L, 22R when they are lowered to their limit.

[0029] The left-side illumination direction change device 32L can change the illumination direction of the light LL by swinging the left-side illumination device 30L up and down in accordance with an illumination direction command sent from the control device 15B.

[0030] The right-side lighting device 30R is provided on the right side wall of the mast 21 (more specifically, the outer mast) via a right-side illumination direction change device 32R. As in the first embodiment, the right-side lighting device 30R irradiates red light LR from the vehicle body 10 side toward the space above the forks 22L, 22R, i.e., the space that may be occupied by a load B placed on the forks 22L, 22R. In this embodiment, the right-side lighting device 30R is provided at a height Hth2 from the forks 22L, 22R when they are lowered to their limit.

[0031] The right irradiation direction change device 32R can change the irradiation direction of the light LR by swinging the right lighting device 30R up and down in accordance with an irradiation direction command sent from the control device 15B.

[0032] The height detector 16B is an ultrasonic distance sensor provided at the top of the mast 21, that is, at a position from which 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 (lifting 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.

[0033] The height detector 16B may output a detection signal corresponding to the height 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.

[0034] The control device 15B controls the lighting state of the lighting devices 30L, 30R based on the height H of the load B. More specifically, as shown in Fig. 6, when the height H of the load B does not exceed the aforementioned Hth2 (hereinafter referred to as the "threshold"), the control device 15B sets the lighting state of the lighting devices 30L, 30R to "off," and when the height H of the load B exceeds the threshold Hth2, the control device 15B sets the lighting state of the lighting devices 30L, 30R to "on."

[0035] The control device 15B generates an illumination direction command such that the illumination devices 30L, 30R point upward as the height of the forks 22L, 22R increases. More specifically, the control device 15B generates an illumination direction command such that the illumination devices 30L, 30R illuminate positions that are higher than the forks 22L, 22R by the threshold value Hth2.

[0036] 7(A), when the forks 22L, 22R are lowered to their limit and the height H of the load B placed on the forks 22L, 22R exceeds the threshold Hth2, the control device 15B turns on the lighting devices 30L, 30R and sends an illumination direction command corresponding to the lifting height to the illumination direction change devices 32L, 32R to orient the lighting devices 30L, 30R horizontally. As a result, the lighting devices 30L, 30R illuminate a position that is higher than the forks 22L, 22R by the threshold Hth2.

[0037] 7(B), when the forks 22L, 22R are raised to a certain extent and the height H of the load B placed on the forks 22L, 22R exceeds the threshold value Hth2, the control device 15B turns on the lighting devices 30L, 30R and sends an illumination direction command corresponding to the lifting height to the illumination direction change devices 32L, 32R to direct the lighting devices 30L, 30R diagonally upward. As a result, the lighting devices 30L, 30R illuminate a position that is higher than the forks 22L, 22R by the threshold value Hth2.

[0038] As shown in FIGS. 7(C) and 7(D), when the height H of the load B placed on the forks 22L and 22R does not exceed the threshold value Hth2, the control device 15B turns off the lighting devices 30L and 30R.

[0039] The threshold value Hth2 is set near the upper limit of the height at which it is thought that load B will hardly collapse or tip over.

[0040] In this way, the warning device (30L, 30R, 32L, 32R, 15B) and forklift 1B of this embodiment, like the first embodiment, can clearly notify the operator M seated in the driver's seat 11 that the height H of the load B is too high, i.e., the extent to which the height H of the load B exceeds the threshold value Hth2.

[0041] Note that the first embodiment is based on the idea that the higher the height H of the load B with respect to the road surface G, the greater the danger, and the second embodiment is based on the idea that the higher the height H of the load B with respect to the forks 22L and 22R, the greater the danger.

[0042] [Modification Example] As described above, the embodiments of the warning device and the forklift according to the present invention have been described, but the present invention is not limited to these.

[0043] For example, as shown in Fig. 8(A), the control device 15A of the forklift 1A (warning device) may turn off the lighting devices 30L and 30R when H≦Hth1, turn on the lighting devices 30L and 30R in blue when Hth1<H≦Hth1’, and turn on the lighting devices 30L and 30R in red when Hth1’<H. The same applies to the control device 15B of the forklift 1B (warning device). Note that Hth1’ (Hth2’) is a predetermined threshold value.

[0044] Also, as shown in Fig. 8(B), the control device 15A of the forklift 1A (warning device) may turn off the lighting devices 30L and 30R when H≦Hth1, turn on the lighting devices 30L and 30R in blue when Hth1<H≦Hth1’, and blink the lighting devices 30L and 30R in blue when Hth1’<H. The same applies to the control device 15B of the forklift 1B (warning device). Note that Hth1’ (Hth2’) is a predetermined threshold value.

[0045] Moreover, the forklifts 1A and 1B (warning devices) may be provided with at least one lighting device that irradiates light from the vehicle body 10 side toward the space on the forks 22L and 22R. That is, it is not essential in the present invention that one lighting device is provided on each of the left and right side walls of the mast.

[0046] Furthermore, the height detectors 16A and 16B are not limited to ultrasonic distance sensors. For example, the height detectors 16A and 16B may be sensors that detect the height H by analyzing image data acquired by a camera. [Explanation of symbols]

[0047] 1A, 1B Forklift 10 Vehicle body 11 Driver's seat 12 Operating device 13 Head guard 14 Running gear 15A, 15B control device 16A, 16B Height detector 20 Cargo handling equipment 21 Mast 22L, 22R fork 30L left side lighting device 30R Right side lighting device 32L Left side lighting direction change device 32R Right side illumination direction change device

Claims

1. A warning device provided on a forklift truck having a vehicle body with a driver's seat and a fork provided in front of the vehicle body, a lighting device that irradiates light from the driver's seat side toward a space above the forks that may be occupied by a load that is a loading target; a control device that controls the lighting state of the lighting device based on the height of the load on the forks; Equipped with The control device switches the lighting state from off to on or flashing when the height of the load on the fork exceeds a predetermined threshold. A warning device characterized by:

2. The height of the load is measured from the road surface.

2. The warning device according to claim 1.

3. The height of the load is the height based on the fork 2. The warning device according to claim 1.

4. The lighting device further includes an illumination direction change device that can change the direction of illumination by the lighting device, The control device sends an irradiation direction command corresponding to the height of the fork to the irradiation direction changing device.

4. The warning device according to claim 3.

5. A forklift truck having a vehicle body with a driver's seat and a fork provided in front of the vehicle body, a lighting device that irradiates light from the driver's seat side toward a space above the forks that may be occupied by a load that is a loading target; a control device that controls the lighting state of the lighting device based on the height of the load on the forks; Equipped with The control device switches the lighting state from off to on or flashing when the height of the load on the fork exceeds a predetermined threshold. A forklift characterized by:

6. The height of the load is measured from the road surface.

6. The forklift according to claim 5.

7. The height of the load is the height based on the fork 6. The forklift according to claim 5.

8. The lighting device further includes an illumination direction change device that can change the direction of illumination by the lighting device, The control device sends an irradiation direction command corresponding to the height of the fork to the irradiation direction changing device.

8. The forklift according to claim 7.

Images