Forklift and warning device

Abstract

To provide a forklift and a warning device capable of making an operator intuitively grasp that an undesirable event may occur due to operation of an operation part for cargo handling.SOLUTION: A forklift 1 includes a cargo handling operation part 12 operated by an operator M for operating a fork 14, an irradiation part 17 for irradiating the cargo handling operation part 12 with visible light, and a control part for controlling the irradiation part 17 so that the cargo handling operation part 12 is irradiated while the cargo handling operation part 12 is operated when a specific condition is satisfied.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a forklift truck equipped with a load handling operation unit that is operated by an operator to operate the forks, and a warning device. [Background technology]

[0002] Generally, a forklift truck on which an operator rides is equipped with a cargo handling operation unit that is made up of operation 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. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7481081 Summary of the Invention [Problem to be solved by the invention]

[0004] 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 load supported by the forks to fall (i.e., the load 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 call attention to the operation of the load handling operation unit.

[0005] However, in a configuration in which a warning message is displayed on a display, the operator must shift his or her gaze to the display to read the warning message. Furthermore, in 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 the sound is difficult to hear due to surrounding noise, hearing impairment, or the like. Therefore, there is a problem in that the operator cannot intuitively grasp that an undesirable event may occur due to the operation of the cargo handling operation unit.

[0006] The present invention has been made in consideration of the above circumstances, and its object is to provide a forklift and a warning device that allow the operator to intuitively understand that an undesirable event may occur due to the operation of the loading and unloading operation unit. [Means for solving the problem]

[0007] In order to solve the above problems, the forklift according to the present invention is characterized by comprising: a loading operation unit operated by an operator to operate the forks; an illumination unit capable of irradiating the loading operation unit with visible light; and a control unit that controls the illumination unit so that the loading operation unit is illuminated while the loading operation unit is being operated when certain conditions are met.

[0008] Furthermore, it is preferable that the forklift truck further 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 support cargo, wherein the cargo handling operation unit includes a lift lever for moving the forks in an up and down direction, and the control unit sets 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 satisfied, controls the illumination unit so that the lift lever is illuminated while the lift lever is being operated to move the forks upward.

[0009] Furthermore, it is preferable that 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 loading operation unit includes a tilt lever for tilting the forks in the forward and backward directions, and the control unit sets the specific condition as being that the high-lift state is detected by the lift sensor and that the cargo support state is detected by the load sensor, and when the specific condition is satisfied, controls the illumination unit so that the tilt lever is illuminated while the tilt lever is being operated to tilt the forks forward.

[0010] Furthermore, it is preferable that the forklift 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 that the specific conditions include a condition regarding the height of the forks detected by the lift sensor or a condition regarding the tilt of the forks in the fore-and-aft direction detected by the tilt sensor.

[0011] Furthermore, it is preferable that the cargo handling operation unit includes a lift lever for moving the forks in an up-down direction and a tilt lever for tilting the forks in a forward-backward direction, and that the illumination unit is configured to be able to illuminate visible light individually onto each of the lift lever and the tilt lever.

[0012] In order to solve the above-mentioned problems, the warning device according to the present invention is characterized by comprising an irradiation unit capable of irradiating visible light onto a loading operation unit operated by an operator to operate the forks of a forklift, and a control unit that controls the irradiation unit so that the loading operation unit is illuminated while the loading operation unit is being operated when certain conditions are met. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a forklift and a warning device that allow an operator to intuitively understand that an undesirable event may occur due to operation of a cargo handling operation unit. [Brief explanation of the drawings]

[0014] [Figure 1] 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. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of the forklift according to the embodiment. [Figure 3] 10 is a flowchart showing a control flow of an irradiation unit. DETAILED DESCRIPTION OF THE INVENTION

[0015] As shown in Fig. 1, the forklift 1 according to this embodiment is a counterbalance forklift, and includes a riding section 11, a cargo handling operation section 12, a head guard 13, forks 14, a lift device 15, a tilt device 16, and an illumination section 17. The illumination section 17 constitutes a warning device of the present invention that is mounted on the forklift 1.

[0016] The riding section 11 is composed of a driver's seat in which an operator M rides. A cargo handling operation section 12 that is operated by the operator to operate the forks 14 is provided in front of the riding section 11, and a head guard 13 that protects the operator M is provided above the riding section 11.

[0017] 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 of the levers 12A, 12B is configured to return to a neutral position when the operator M releases their hands from the levers 12A, 12B.

[0018] 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.

[0019] The fork 14 extends in the front-rear direction X and is composed of two claws spaced apart from each other in the left-right direction Y. The fork 14 directly supports a load (not shown) by being inserted into the load, or indirectly supports the load by being inserted into a pallet (not shown) that supports the load. The fork 14 is attached to a lift bracket 15B that constitutes the lift device 15.

[0020] 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 is extendable in the vertical direction Z, a lift bracket 15B that can move up and down 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, thereby moving the forks 14 upward (i.e., raising them). The lift device 15 also retracts the mast 15A and lowers the lift bracket 15B, thereby moving the forks 14 downward (i.e., lowering them).

[0021] The tilt device 16 tilts the forks 14 in the front-to-rear 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).

[0022] The illumination unit 17 is configured with an LED floodlight capable of emitting visible light onto the cargo handling operation unit 12. When the illumination unit 17 emits visible light onto 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. It is preferable that the illumination unit 17 emits visible light of 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 onto each of the lift lever 12A and the tilt lever 12B by changing the direction in which the visible light is emitted.

[0023] 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 a warning device of the present invention that is mounted on the forklift 1.

[0024] 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 (i.e., the position in the vertical direction Z) of the forks 14 by acquiring operation information of the lift device 15. The lift sensor 21 outputs a signal indicating the detection result of the lift height to the control unit 24.

[0025] The tilt sensor 22 is a sensor for detecting a forward tilt state in which the forks 14 tilt downward as they move forward, i.e., toward the tips of the forks 14, and detects the tilt of the forks 14 in the fore-and-aft direction X by acquiring operation information of the tilt device 16. The tilt sensor 22 outputs a signal indicating the tilt detection result to the control unit 24.

[0026] The load sensor 23 is a sensor for detecting a 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.

[0027] When specific conditions are met, the control unit 24 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. 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 angle of the forks 14 in the fore-and-aft direction X detected by the tilt sensor 22.

[0028] Specifically, the control unit 24 determines that a forward tilt state is detected by the tilt sensor 22 and a luggage support state is detected by the load sensor 23 as specific condition 1, and when this specific condition 1 is satisfied, 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.

[0029] Furthermore, the control unit 24 determines that a high-lift state is detected by the lift sensor 21 and that a load support state is detected by the load sensor 23 as specific condition 2, and when this specific condition 2 is satisfied, controls the illumination unit 17 so that the tilt lever 12B is illuminated while the tilt lever 12B is operated to tilt the fork 14 forward.

[0030] 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 specific condition 1 or specific condition 2 is satisfied based on the outputs of the sensors 21 to 23.

[0031] When the control unit 24 determines that a specific condition is not met (step S1: NO), the possibility of cargo collapse occurring is low or nonexistent, so the control unit 24 does not control the illumination unit 17 to illuminate the cargo handling operation unit 12.

[0032] On the other hand, when the control unit 24 determines that the specific condition is satisfied (step S1: YES), it determines whether or not a specific operation is being performed based on the output of the cargo handling operation unit 12 (step S2).

[0033] Specifically, when the control unit 24 determines in step S1 that specific condition 1 is satisfied, it determines in step S2 based on the output of the lift lever 12A whether or not the following specific operation 1 has been performed. Specific operation 1: Operation of lift lever 12A to move fork 14 upward

[0034] Furthermore, when it is determined in step S1 that specific condition 2 is satisfied, the control unit 24 determines in step S2 whether or not the following specific operation 2 is being performed, based on the output of the tilt lever 12B. Specific operation 2: Operation of tilt lever 12B to tilt fork 14 forward

[0035] 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 loading and unloading operation unit 12, because the operator M has not performed an operation on the loading and unloading operation unit 12 that would cause the cargo to collapse.

[0036] On the other hand, when the control unit 24 determines that a specific operation has been performed (step S2: YES), the operator M is operating the cargo handling operation unit 12 in a way that causes cargo to collapse, and therefore the control unit 24 controls the irradiation unit 17 to start irradiating the cargo handling operation unit 12 (step S3). At this time, when the control unit 24 determines in step S2 that specific operation 1 has been performed, it controls the irradiation unit 17 to irradiate the lift lever 12A with visible light, and when the control unit 24 determines in step S2 that specific operation 2 has been performed, it controls the irradiation unit 17 to irradiate the tilt lever 12B with visible light.

[0037] While the irradiating unit 17 is irradiating the cargo handling operation unit 12, the control unit 24 determines whether or not the specific operation has ceased to be performed (step S4). That is, the control unit 24 determines whether or not 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 irradiated.

[0038] When the control unit 24 determines that a specific operation is being performed (step S4: NO), since the operator M continues to operate the cargo handling operation unit 12, which causes the cargo to collapse, the control unit 24 does not control the irradiation unit 17 to stop the irradiation, and maintains the irradiation of the cargo handling operation unit 12.

[0039] On the other hand, when the control unit 24 determines that the specific operation has stopped (step S4: YES), the control unit 24 controls the irradiation unit 17 to stop irradiating the cargo handling operation unit 12 because the operator M is not operating the cargo handling operation unit 12 in a way that would cause the cargo to collapse (step S5).

[0040] In this embodiment, the following effects are obtained. (1) The forklift 1 includes an illuminating unit 17 that can irradiate the cargo handling operation unit 12 with visible light, and a control unit 24 that controls the illuminating unit 17 so that the cargo handling operation unit 12 is illuminated while the cargo 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 cargo handling operation unit 12, that the forklift 1 is in an unusual state and that the cargo 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 cargo handling operation unit 12.

[0041] (2) When the 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.

[0042] (3) When the above-described 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.

[0043] (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. According to this configuration, a situation in which a load may fall from the forks 14 can be specified by the height of the forks 14 or the tilt of the fores 14 in the fore-and-aft direction X.

[0044] (5) The illumination unit 17 is configured to be able to individually illuminate the lift lever 12A and the tilt lever 12B 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 he or she should not operate the lift lever 12A or the tilt lever 12B that he or she is currently operating.

[0045] The present invention is not limited to the above-described embodiment, and the above configurations can be modified. For example, the following modifications can be made, or the following modifications can be combined to make the present invention.

[0046] The configuration of the irradiating unit 17 may be changed as appropriate. For example, the irradiating unit 17 may be provided somewhere other than the head guard 13. Furthermore, the irradiating unit 17 may be configured to irradiate both the lift lever 12A and the tilt lever 12B with visible light at the same time.

[0047] Alternatively, the illumination unit 17 may be configured with a plurality of LED floodlights, one of which is configured to illuminate the lift lever 12A with visible light, and another of which is 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.

[0048] The control unit 24 may determine whether or not 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. Also, the control unit 24 may determine whether or not 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.

[0049] 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. 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 specific conditions may include a condition related to the forward and backward positions of the forks detected by the reach sensor. The specific conditions may also include a condition related to the traveling speed of the forklift detected by a vehicle speed sensor.

[0050] The manner in which visible light is emitted by the irradiating unit 17 may be changed as appropriate. For example, the irradiating unit 17 may irradiate visible light intermittently. That is, the control unit may blink the irradiating unit 17 while maintaining the illumination of the cargo handling operation unit 12.

[0051] 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) provided on the forklift, or a warning sound may be emitted from a buzzer (not shown) provided on the forklift. [Explanation of symbols]

[0052] 1 forklift 12 Cargo handling operation unit 12A Lift lever 12B Tilt lever 14 Fork 17 Irradiation unit 21 Lift sensor 22 Tilt sensor 23 Load sensor 24 Control Unit M Operator X Anteroposterior direction Y left / right direction Z vertical direction

Claims

1. 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; and 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 forklift characterized by:

2. 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, 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 luggage support state, and when the specific condition is satisfied, controls the illumination unit so that the lift lever is illuminated while the lift lever is being operated to move the fork upward.

2. The forklift according to claim 1.

3. 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, 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-support 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 fork forward.

2. The forklift according to claim 1.

4. 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, The specific conditions include a condition regarding the lift height of the forks detected by the lift sensor, or a condition regarding the tilt angle of the forks in the front-rear direction detected by the tilt sensor.

2. The forklift according to claim 1.

5. 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 illuminating unit is configured to be able to irradiate the lift lever and the tilt lever with visible light individually.

2. The forklift according to claim 1.

6. 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; and 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 warning device characterized by:

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