cargo handling vehicle

Abstract

To provide a cargo handling vehicle capable of detecting an abnormality that a hook part of a safety belt remains suspended from a guide bar of a head guard at a key-off.SOLUTION: A cargo handling vehicle has: a vehicle body; a driving cab installed at the front of the vehicle body and capable of elevating / lowering with respect to the vehicle body; a cargo handling tool provided in the driving cab; a head guard provided above the driving cab; a guide bar installed in the head guard and capable of suspending a hook part of a safety belt; and a detecting sensor for detecting the presence / absence of the hook part in the guide bar. The cargo handling vehicle has: a notification body for notifying of an abnormality based on the presence / absence of the hook part in the guide bar; and a controller 42 connected to the detecting sensor to control the notification body. The controller 42 controls the notification body to perform notification as the abnormality of the safety belt when the hook part is detected by the detecting sensor when being changed from a key-on state to a key-off state and the hook part is detected by the detecting sensor when being newly changed from the key-off state to the key-on state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cargo handling vehicle. [Background technology]

[0002] As a conventional technique related to cargo handling vehicles, for example, a safety belt fastening device for a picking forklift is known, as disclosed in Patent Document 1. This safety belt fastening device for a picking forklift is equipped with a safety bar to which the safety belt is fastened, an optical sensor that detects whether the safety belt is fastened to the safety bar, and a red light and an audio alarm that warn that the safety belt is not fastened to the safety bar.

[0003] When the safety belt is fastened to the safety bar, the light from the light projector is blocked by the hook, and it is detected that the safety belt is fastened to the safety bar.When the safety belt is not fastened to the safety bar, the light from the light projector is not blocked, and it is detected that the safety belt is not fastened, and a red light and an audio alarm are activated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-18212 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the safety belt fastening device for a picking forklift disclosed in Patent Document 1 cannot detect an abnormality where the safety belt remains connected to the safety bar after the forklift has stopped operating. In other words, with this type of cargo handling vehicle, there is a problem in that it cannot detect an abnormality where the hook part of the safety belt continues to hang on the guide bar of the head guard when the key of the cargo handling vehicle is in the off position.

[0006] The present invention has been made in consideration of the above problems, and its object is to provide a cargo handling vehicle that can detect an abnormality in which the hook portion of the safety belt continues to hang from the guide bar of the head guard when the key is turned off. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a cargo handling vehicle having a vehicle body, a driver's cab provided at the front of the vehicle body and capable of raising and lowering relative to the vehicle body, a loading device provided on the driver's cab, a head guard provided above the driver's cab, a guide bar provided on the head guard and enabling a hook portion of a safety belt to be suspended, and a detection sensor that detects the presence or absence of the hook portion on the guide bar, the cargo handling vehicle also having an alarm that issues an alert based on the presence or absence of the hook portion on the guide bar, and a controller connected to the detection sensor and controlling the alarm, the controller controlling the alarm so as to issue an alert as to an abnormality in the safety belt when the hook portion is detected by the detection sensor when the key is turned off from the key-on state and when the hook portion is detected by the detection sensor when the key is turned on again from the key-off state At the same time, control is performed to limit at least one of the speed of the vehicle body and the elevation of the driver's cab. It is characterized by:

[0008] In this invention, if the detection sensor detects the hook portion when the key is turned off from the key-on state, and if the hook portion is detected when the key is turned on again from the key-off state, the controller controls the alarm to warn of an abnormality in the safety belt. If the hook portion is hanging from the guide bar after key-off and again when the key is turned on again after key-off, it is highly likely that the operator is not wearing the safety belt, but the alarm can warn of an abnormality in the safety belt to alert the operator who is on board the cargo handling vehicle when the key is turned on. In addition to notifying the operator of an abnormality in the safety belt, the alarm is controlled to limit at least one of the vehicle speed and the driver's cab ascent and descent, allowing the operator to intuitively recognize an abnormality in the safety belt.

[0009] In the above-described cargo handling vehicle, the detection sensor may be configured to detect the presence or absence of the hook portion on the guide bar even when the key is turned off until a preset time has elapsed since the key was turned off. In this case, the detection sensor can detect the presence or absence of the hook portion for a preset time from when the key is turned off, making it possible to detect an abnormality in which the hook portion continues to hang even after the key is turned off.In addition, after the set time has elapsed, the detection sensor stops detecting the hook portion, thereby reducing the power consumption of the detection sensor in the key-off state.

[0010] In addition, in the above-mentioned cargo handling vehicles, The present invention , a loading vehicle having a vehicle body, a driver's cab provided at the front of the vehicle body and capable of raising and lowering relative to the vehicle body, a loading device provided on the driver's cab, a head guard provided above the driver's cab, a guide bar provided on the head guard and enabling a hook portion of a safety belt to be suspended, and a detection sensor for detecting the presence or absence of the hook portion on the guide bar; an alarm that issues an alert based on the presence or absence of the hook portion on the guide bar, and a controller connected to the detection sensor and controlling the alarm, wherein the controller controls the alarm so that when the hook portion is detected by the detection sensor when the key is turned off from a key-on state and when the hook portion is detected by the detection sensor when the key is turned on again from a key-off state, the alarm issues an alert to the driver so that the controller issues an alert to the driver so that the driver can raise an alert to the driver that the hook portion is abnormal with the safety belt; The detection sensor detects the presence or absence of the hook portion on the guide bar while the key is in an off state. Characterized by . In the present invention The key-on state is changed to the key-off state, and the detection sensor detects the presence or absence of the hook portion during the key-off state. Therefore, the detection sensor can reliably detect the presence or absence of the hook portion during the key-off state.

[0012] Furthermore, in the above-described cargo handling vehicle, when the hook portion is detected by the detection sensor when the key is turned off and when the hook portion is detected by the detection sensor after the key is turned on and an abnormality in the safety belt is reported, the controller may be configured to release the abnormality in the safety belt by removing the hook portion from the guide bar. In this case, even if the hook portion is detected when the key is turned off and the hook portion is detected when the key is turned on again from the key-off state, causing an abnormality in the safety belt, the abnormality in the safety belt can be resolved by removing the hook portion from the guide bar. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a cargo handling vehicle that can detect an abnormality in which the hook portion of the safety belt continues to hang on the guide bar of the head guard when the key is turned off. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a side view of an order-picking forklift truck according to an embodiment of the present invention. [Figure 2] FIG. 1 is a perspective view of an order-picking forklift according to an embodiment of the present invention. [Figure 3] FIG. 1 is a perspective view of a main part of an order-picking forklift according to an embodiment of the present invention. [Figure 4] FIG. 2 is a block diagram showing the electrical configuration of the order-picking forklift according to the present embodiment. [Figure 5] FIG. 10 is a flowchart showing the process of restricting the operation of the order-picking forklift according to the present embodiment. [Figure 6] FIG. 10 is a diagram showing a time chart of key switch and hook portion detection in the case of an abnormality in the safety belt. [Figure 7] FIG. 10 is a diagram showing a time chart according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0015] A cargo handling vehicle according to this embodiment will be described below with reference to the drawings. The cargo handling vehicle according to this embodiment is an order-picking forklift. The terms "front / back," "left / right," and "up / down" that specify directions are used based on the state in which the operator of the order-picking forklift is seated in the driver's cab and facing the forward direction of the order-picking forklift.

[0016] As shown in FIG. 1, an order-picking forklift (hereinafter simply referred to as a "forklift") 10 serving as a cargo handling vehicle has a vehicle body 11, and front wheels 12 are provided at the front of the vehicle body 11. The front wheels 12 are drive wheels and steerable wheels, and are located near the center of the vehicle body 11 in the left-right direction. The vehicle body 11 is equipped with a travel motor 13, which is an electric motor for travel, and the travel motor 13 drives the front wheels 12. The vehicle body 11 is also equipped with a steering device (not shown), which steers the front wheels 12. The rear of the vehicle body 11 is equipped with a pair of left and right legs 14 extending rearward, and rear wheels 15 are provided at the tips of the legs 14. The rear wheels 15 are rollable driven wheels.

[0017] The forklift 10 has a mast assembly 16. The mast assembly 16 is provided at the rear of the vehicle body 11 and includes a mast 17 and a cab 18 that can be raised and lowered relative to the mast 17. The mast 17 has an outer mast 19 and an inner mast 20 that can be raised and lowered relative to the outer mast 19. A sprocket 21 around which a chain 22 is hung is provided at the upper end of the inner mast 20. The cab 18 is suspended by the chain 22. The inner mast 20 is raised and lowered by driving a cargo handling motor 23 mounted on the vehicle body 11. The cab 18 is raised and lowered as the inner mast 20 is raised and lowered relative to the outer mast 19.

[0018] Next, the cab 18 will be described. As shown in FIG. 2, the cab 18 is a substantially rectangular platform on which an operator can sit. A pair of forks 24 serving as loading and unloading equipment is provided below the cab 18. The forks 24 extend rearward from the bottom of the cab 18. A pair of left and right pillars 25 are erected in front of the cab 18. The pillars 25 support a head guard 35, which will be described later. A front wall 26 is erected from the cab 18 between the left and right pillars 25. The front wall 26 is about half the height of the pillars 25, and a metal protective net 27 is provided above the front wall 26.

[0019] As shown in FIG. 2, an instrument panel 28 is provided on the front wall 26. The instrument panel 28 is provided with a steering wheel 29, an accelerator lever 30, a load handling lever 31, and a display 32. The cab 18 is provided with an operating pedal 33. The steering wheel 29 is a wheel that the operator operates to change direction while traveling. The accelerator lever 30 is a lever for operating the accelerator when moving the forklift 10 forward or backward. The load handling lever 31 is a lever for raising and lowering the cab 18. The accelerator lever 30 and the load handling lever 31 correspond to operating parts.

[0020] The display 32 is equipped with a display unit (not shown) that displays various information and a speaker unit (not shown) that generates warning sounds. The display unit of the display 32 can also emit light and flash. The display 32 also generates warning sounds, so it serves as an alarm. A pair of left and right side gates 34 for operator protection are provided near the top of the front wall 26. The side gates 34 are L-shaped gate bars that can be moved up and down and are fixed in a retracted position, which is an upwardly rotated position, and a guard position, which is a downwardly rotated position. Figure 1 shows the side gate 34 in the guard position, and Figure 2 shows the side gate 34 in the retracted position.

[0021] Here, the head guard 35 will be described. As shown in Fig. 3, the head guard 35 has a frame body 36, a plurality of horizontal partition members 37 that separate the space defined by the frame body 36 into front and rear, and a vertical partition member 38 that divides the space defined by the frame body 36 into two, left and right. For ease of explanation, the rear portion of the frame body 36 is not shown in Fig. 3.

[0022] As shown in FIG. 3 , the head guard 35 has a guide bar 39 for suspending a hook portion 51 of a safety belt 50 worn by the operator when boarding the cab 18. The safety belt 50 has a waist belt portion (not shown) worn around the operator's torso, the hook portion 51 suspended from the guide bar 39, a rope portion 52 connected to the waist belt, and a connecting portion 53 connecting the hook portion 51 and the rope portion 52. The hook portion 51 has a hook-shaped hook main body 54, a stopper body 55 that opens and closes an opening in the hook main body 54, and a through hole 56 for connecting to the connecting portion 53. When the stopper body 55 is pushed in and the hook main body 54 is hooked onto the guide bar 39, and then the stopper body 55 returns to its original position, the hook portion 51 will not come off the guide bar 39.

[0023] The guide bar 39 of this embodiment is provided in the head guard 35 between the rear of the frame body 36 and the rearmost horizontal partition member 37. The guide bar 39 allows the hook portion 51 to move back and forth in one direction. The guide bar 39 of this embodiment has a plurality of guide members 40, 41 arranged approximately parallel to each other.

[0024] The head guard 35 is equipped with a photoelectric sensor 60 that detects the presence or absence of the hook portion 51 on the guide bar 39. As shown in FIG. 3 , the photoelectric sensor 60 has a light-projecting unit 62 that projects sensor light (laser light) L and a light-receiving unit 61 that receives the projected sensor light L. The light-projecting unit 62 is attached to the head guard 35 via a light-projecting bracket 63 that is bent into an L shape. The light-projecting unit 62 is located to the right of the guide members 40 and 41, and the optical axis of the sensor light L projected from the light-projecting unit 62 is in the left-right direction. The light-receiving unit 61 is attached to the head guard 35 via a light-receiving bracket 64 that is bent into an L shape. The light-receiving unit 61 is located to the left of the guide members 40 and 41, and is provided at a position where it can receive the sensor light L projected from the light-projecting unit 62. The left-right positions of the light-projecting unit 62 and the light-receiving unit 61 relative to the guide members 40 and 41 may be changed. Furthermore, the photoelectric sensor 60 may be a diffuse reflection type photoelectric sensor in which the light projecting section 62 and the light receiving section 61 are integrated. In this case, a reflector (for example, a mirror) that reflects the sensor light L is installed on the opposite side of the guide members 40 and 41.

[0025] Next, the electrical configuration of the forklift 10 will be described. As shown in FIG. 4, the forklift 10 has a controller 42 that controls each part of the forklift 10. The controller 42 includes a CPU 43 and a storage unit 44 including RAM, ROM, etc. The controller 42 may also include dedicated hardware that executes at least some of the various processes, such as an application specific integrated circuit (ASIC). The controller 42 may be configured as a circuit including one or more processors that operate according to a computer program, one or more dedicated hardware circuits such as ASICs, or a combination thereof.

[0026] The memory unit 44 stores program codes or commands configured to cause the CPU 43 to execute processing. The memory unit 44 stores various programs for controlling each part of the forklift 10. The controller 42 is electrically connected to the traveling motor 13, the cargo handling motor 23, and the display 32.

[0027] The steering wheel 29 is provided with a steering sensor 45 that detects the amount of steering, and the steering sensor 45 is connected to the controller 42. The accelerator lever 30 is provided with an accelerator sensor 46 that detects the amount of accelerator, and the accelerator sensor 46 is connected to the controller 42. In addition, the cargo handling lever 31 is provided with a cargo handling lever sensor 47 that detects the amount of operation of the cargo handling lever 31, and the cargo handling lever sensor 47 is connected to the controller 42. Furthermore, a side gate sensor 48 is provided that detects the retracted position and guard position of the side gate 34, and the side gate sensor 48 is connected to the controller 42.

[0028] A key switch 49 is also connected to the controller 42. As shown in FIG. 2, the key switch 49 is provided on the instrument panel 28. The key switch 49 is a switch that outputs a start signal for starting electric devices such as the travel motor 13 and the cargo motor 23. The key switch 49 is operated by an operator when he inserts a key (not shown) and turns it. The key switch 49 has a key cylinder that includes physical contacts inside. The key cylinder switches between multiple switch states depending on the operating position of the key switch 49. The switch states are a key-off state (key switch OFF state) and a key-on state (key switch ON state). The key switch 49 outputs a signal related to the switch state to the controller 42.

[0029] When the key switch 49 is turned off so that the switch state is in the key-off state, it outputs an OFF signal to the controller 42. When the key switch 49 is turned on so that the switch state is in the key-on state, it outputs an ON signal to the controller 42.

[0030] The controller 42 receives an operation signal from an accelerator sensor 46 based on the operation of the accelerator lever 30 and controls the rotation speed of the travel motor 13. As a result, the forklift 10 travels in the direction of travel corresponding to the operation direction of the accelerator lever 30 at a speed corresponding to the amount of operation. The controller 42 receives an operation signal from a cargo handling lever sensor 47 based on the operation of the cargo handling lever 31 and controls the rotation speed of the cargo handling motor 23. As a result, the forklift 10 moves up or down in the direction of lifting or lowering corresponding to the operation direction of the cargo handling lever 31 at a speed corresponding to the amount of operation. The lift height of the cab 18 is transmitted to the controller 42 based on the rotation speed of the cargo handling motor 23. The controller 42 also receives a signal from a side gate sensor 48 indicating that the side gate 34 has been detected in the retracted position and the guard position.

[0031] Next, notification of an abnormality in the safety belt 50 by the forklift 10 according to this embodiment will be described. The abnormality in the safety belt 50 described here is an abnormality caused by the hook portion 51 continuing to hang from the guide bar 39 even when the key is turned off. As shown in the flow diagram of FIG. 5, when the key switch 49 is turned from the key-on state to the key-off state, the controller 42 determines whether the hook portion 51 is hanging from the guide bar 39 (step S001). Whether the hook portion 51 is hanging from the guide bar 39 depends on whether the photoelectric sensor 60 detects the hook portion 51. When the photoelectric sensor 60 detects the hook portion 51, the controller 42 determines that the hook portion 51 is hanging from the guide bar 39.

[0032] If the controller 42 determines in step S001 that the hook portion 51 is suspended from the guide bar 39, the controller 42 then determines whether the hook portion 51 will be suspended from the guide bar 39 when the key is turned on from the key-off state (step S002). As shown in FIG. 6, the photoelectric sensor 60 of this embodiment can detect the hook portion 51 even when the key is turned off from the key-on state until a preset time T1 has elapsed since the key was turned off. Once the set time T1 has elapsed, the photoelectric sensor 60 cannot detect the hook portion 51. In other words, the period from the set time T1 until the next key-on is a non-detection time T2 during which the photoelectric sensor 60 does not detect the hook portion 51.

[0033] When the key switch 49 is turned from the key-off state to the key-on state, if it is determined that the hook portion 51 is suspended from the guide bar 39, the controller 42 notifies the operator of an abnormality in the safety belt 50 (step S003). The abnormality in the safety belt 50 is notified by the display 32 as an alarm. The display portion of the display 32 as an alarm device displays a message indicating an abnormality in the safety belt 50, and the speaker portion generates an alarm sound indicating an abnormality in the safety belt 50.

[0034] If it is determined in step S001 that the hook portion 51 is not suspended from the guide bar 39 when the key is turned off, the controller 42 ends the flow without notifying of an abnormality in the safety belt 50 when the key is turned on. Also, if it is determined in step S002 that the hook portion 51 is not suspended from the guide bar 39 when the key is turned on from the key-off state, the controller 42 ends the flow without notifying of an abnormality in the safety belt 50 when the key is turned on.

[0035] In this embodiment, when an abnormality in the safety belt 50 is notified to the operator, the operation of the forklift 10 is restricted (step S004). Specifically, the operation restriction of the forklift 10 is described as follows: the controller 42 controls the travel motor 13 so that the forklift 10 cannot travel above a preset upper limit vehicle speed. In other words, the controller 42 restricts the vehicle speed. As another operation restriction, the controller 42 controls the load motor 23 so that the driver's cab 18 cannot be raised and only lowered. In addition to the operation restriction, the controller 42 also activates the display 32 to emit a warning sound. During the operation restriction, the controller 42 controls the display 32 so that a warning sound different from the warning sound indicating an abnormality in the safety belt 50 is emitted when at least one of the accelerator lever 30 and the load handling lever 31 is operated.

[0036] When the operation of the forklift 10 is restricted while an abnormality in the safety belt 50 has been notified, the controller 42 determines whether or not an operation to release the abnormality in the safety belt 50 has been performed (step S005). The operation to release the abnormality in the safety belt 50 is an operation in which the operator temporarily removes the hook portion 51 from the guide bar 39 when the key is on. The operation restriction is released by re-suspending the hook portion 51 from the guide bar 39. By temporarily removing the hook portion 51 from the guide bar 39 while an abnormality in the safety belt 50 has been notified, the photoelectric sensor 60 no longer detects the hook portion 51, and the abnormality in the safety belt 50 is released. Furthermore, by re-suspending the hook portion 51 from the guide bar 39, the photoelectric sensor 60 detects the hook portion 51, and the operation restriction is released.

[0037] Therefore, when the key is turned on, the controller 42 releases the abnormality and operation restriction of the safety belt 50 by removing the hook portion 51 from the guide bar 39 and suspending it again (step S006). The flow ends when the abnormality and operation restriction of the safety belt 50 are released. If it is determined in step S005 that no operation has been performed to release the abnormality of the safety belt 50, the controller 42 maintains the state in which an abnormality of the safety belt 50 is reported and the operation restriction. If the hook portion 51 is not detected when the key is turned on even after the flow for releasing the abnormality and operation restriction of the safety belt 50 has ended, an abnormality of the safety belt 50 is reported, indicating that the hook portion 51 is not suspended from the guide bar 39 when the key is turned on.

[0038] Next, the operation of the forklift 10 according to this embodiment will be described. When the operator of the forklift 10 operates the forklift 10, he or she boards the cab 18 and then hooks the hook portion 51 of the safety harness 50 onto the guide bar 39 to hang it down. With the key switch 49 turned on, when the hook portion 51 hangs down on the guide bar 39, the sensor light L emitted from the light-emitting portion 62 of the photoelectric sensor 60 is blocked, and the light-receiving portion 61 cannot receive the sensor light L. When the sensor light L is blocked, the controller 42 determines that the hook portion 51 is present on the guide bar 39.

[0039] When the hook portion 51 is suspended from the guide bar 39 after the key is turned on, the safety belt 50 is normal, no abnormality in the safety belt 50 is reported, and the forklift 10 is not subject to any operational restrictions. Therefore, when the operator in the cab 18 operates the accelerator lever 30 in a direction corresponding to the direction of travel, the forklift 10 travels at a speed corresponding to the amount of operation of the accelerator lever 30. Furthermore, when the load handling lever 31 is operated, the load handling motor 23 rotates in accordance with the amount of operation of the load handling lever 31. The rotation direction of the load handling motor 23 corresponds to the direction of operation of the load handling lever 31. In other words, the cab 18 is raised or lowered at a speed corresponding to the amount of operation in the lifting / lowering direction corresponding to the direction of operation of the load handling lever 31. The height of the cab 18 is detected based on the rotation speed of the load handling motor 23.

[0040] If the hook portion 51 is not suspended from the guide bar 39 after the key is turned on, the controller 42 reports an abnormality in the safety harness 50, indicating that the hook portion 51 is not suspended from the guide bar 39 when the key is turned on, and the forklift 10 is subject to an operation restriction. If the controller 42 determines that the height of the cab 18 is equal to or greater than the threshold and that the hook portion 51 is not on the guide bar 39, it controls the travel motor 13 to prevent the forklift 10 from traveling at a speed exceeding a preset upper limit vehicle speed. Furthermore, if the controller 42 determines that the height of the cab 18 is equal to or greater than the threshold and that the hook portion 51 is not on the guide bar 39, it controls the load motor 23 to disable the raising of the cab 18 and allow only the lowering of the cab 18. If the operator suspends the hook portion 51 from the guide bar 39 while the forklift 10 is subject to an operation restriction, the controller 42 releases the operation restriction.

[0041] Next, we will explain the case where an abnormality occurs in the safety belt 50 caused by the hook portion 51 continuing to hang from the guide bar 39 when the key is off. When stopping the forklift 10 that is in operation after work is completed, the operator changes the key switch 49 from the key-on state to the key-off state. After turning the key off, the operator usually removes the hook portion 51 from the guide bar 39 and stores the safety belt 50 in a designated location.

[0042] Even when the key is turned off from the key-on state, the photoelectric sensor 60 continues to detect the hook portion 51 until the preset time T1 has elapsed since the key was turned off. Therefore, if the hook portion 51 remains suspended from the guide bar 39 when the key is turned off from the key-on state, and if the hook portion 51 is still suspended from the guide bar 39 when the key is turned on from the key-off state, the controller 42 will notify the user of an abnormality in the safety belt 50.

[0043] If the hook portion 51 is detected subsequently from the key-off state to the key-on state, there is a possibility that the operator has not put on the safety belt 50 and that only the safety belt 50 remains on the forklift 10. Therefore, to encourage the operator to confirm and put on the safety belt 50, an abnormality in the safety belt 50 is notified when the conditions of detecting the hook portion 51 in the key-off state and detecting the hook portion 51 in the key-on state subsequent to the key-off state are met. At this time, the display 32 displays a warning indicating an abnormality in the safety belt 50 and also emits a warning sound. An abnormality in the safety belt 50 caused by the detection of the hook portion 51 in the key-off state and the detection of the hook portion 51 in the key-on state subsequent to the key-off state can be released by the operator temporarily releasing the hook portion 51. Then, the operation restriction is released by re-hanging the hook portion 51.

[0044] The forklift 10 according to this embodiment has the following advantages. (1) When the photoelectric sensor 60 detects the hook portion 51 when the key is turned off from the key-on state, and when the hook portion 51 is detected when the key is turned on from the key-off state, the controller 42 controls the display 32 to notify the operator of an abnormality in the safety belt 50. If the hook portion 51 is hanging from the guide bar 39 after the key is turned off and again when the key is turned on following the key-off, it is highly likely that the operator is not wearing the safety belt 50. However, by notifying the operator of an abnormality in the safety belt 50 by the display 32, it is possible to alert the operator who is on board when the key is turned on of the forklift 10.

[0045] (2) When the time elapsed since key-off is within a preset time T1, the photoelectric sensor 60 can detect the presence or absence of the hook portion 51, making it possible to detect an abnormality in which the hook portion 51 continues to hang even after the key is turned off. Furthermore, once the time elapsed since key-off has exceeded the set time T1, the detection of the hook portion 51 by the photoelectric sensor 60 is stopped, thereby reducing the power consumption of the photoelectric sensor 60 in the key-off state.

[0046] (3) When the photoelectric sensor 60 detects the hook portion 51 at key-off and when the photoelectric sensor 60 detects the hook portion 51 after key-on, the controller 42 controls to restrict at least one of the speed of the car body 11 and the elevation of the cab 18. Therefore, the display 32 notifies of an abnormality in the safety belt 50, and the controller 42 is controlled to restrict at least one of the speed of the car body 11 and the elevation of the cab 18, so that the operator can intuitively recognize the abnormality in the safety belt 50.

[0047] (4) When the photoelectric sensor 60 continues to detect the hook portion 51 at key-off and subsequent key-on times and an abnormality in the safety belt 50 is reported, the controller 42 cancels the abnormality in the safety belt 50 caused by the hook portion 51 being detected at key-off by removing the hook portion 51 from the guide bar 39. Furthermore, when the hook portion 51 is suspended from the guide bar 39 at key-on, the controller 42 releases the operation restriction. Therefore, even if the hook portion 51 is detected at key-off and subsequent key-on times and an abnormality in the safety belt 50 occurs, the operator can release the abnormality and operation restriction in the safety belt 50 by removing the hook portion 51 from the guide bar 39 and then suspending it from the guide bar 39.

[0048] (Variation) Next, a forklift 10 according to a modified example will be described. In the forklift according to the modified example, even when the key is turned off from the key-on state, the set time T1 for the elapsed time from the key-off state is not set. Therefore, as shown in FIG. 7, the photoelectric sensor 60 detects the hook portion 51 of the guide bar 39 even during the key-off state. According to this modified example, when the key is turned off from the key-on state, the photoelectric sensor 60 can reliably detect the presence or absence of the hook portion 51 during the key-off state. If a limit switch that does not require a power source and can detect the hook portion 51 is used as a detection sensor instead of the photoelectric sensor 60, power consumption can be reduced.

[0049] The present invention is not limited to the above-described embodiment (including modified examples), and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.

[0050] In the above embodiment (including the modified example), when an abnormality occurs in the safety belt, the operation of the cargo handling vehicle is restricted, but this is not limited to this. For example, when an abnormality occurs in the safety belt, the operation of the cargo handling vehicle may not be restricted, and only an abnormality notification may be issued. Also, as in the above embodiment, the operation of both the vehicle body speed limit and the cab elevation limit may be restricted, but the operation of only one of them may be restricted. In the above embodiment (including the modified example), a photoelectric sensor is used as the detection sensor, but this is not limiting. For example, a contact type sensor may be used as the detection sensor, and any type of sensor may be used as long as it can detect the presence or absence of the hook part of the safety belt. In the above embodiment (including the modified example), a display having a display unit that displays various information and a speaker unit that generates a warning sound is used as the notification device, but this is not limited to this. For example, the notification device may only display a warning on the display, or may not be a display but may generate a warning sound. The display 32 serving as a warning device displays a message indicating an abnormality in the safety belt 50, and the speaker generates a warning sound indicating an abnormality in the safety belt 50. In the above embodiment (including the modified example), an order-picking forklift truck is used as an example of the cargo handling vehicle, but the present invention is not limited to this. Any type or form of cargo handling vehicle may be used as long as it has a guide bar for suspending the hook portion of the safety belt. [Explanation of symbols]

[0051] 10. Forklift 11 Body 13. Traction motor 16 Mast equipment 18 Driver's cab 23 Loading motor 24 Fork 32 Display 35 Head Guard 39 Guide bar 42 Controller 49 key switches 50 Safety Belt 51 Hook part 60 Photoelectric Sensor 61 Light receiving section 62 Light projector L sensor light T1 threshold T2 Non-detection time

Claims

1. The car body and a driver's cab provided at a front portion of the vehicle body and capable of ascending and descending relative to the vehicle body; A loading device provided in the driver's cab; A head guard provided above the driver's cab; a guide bar provided on the head guard to enable the hook portion of the safety belt to be hung; a detection sensor for detecting the presence or absence of the hook portion on the guide bar, an alarm that notifies an abnormality based on the presence or absence of the hook portion in the guide bar; a controller connected to the detection sensor and controlling the notification body, The controller controls the alarm device to notify of an abnormality in the safety belt when the hook portion is detected by the detection sensor when the key is turned off from the key-on state, and when the hook portion is detected by the detection sensor when the key is turned on again from the key-off state, and controls the alarm device to perform at least one of limiting the speed of the vehicle body and limiting the elevation of the driver's cab.

2. 2. The cargo handling vehicle according to claim 1, wherein the detection sensor continues to detect the presence or absence of the hook portion of the guide bar even after the key is turned off until a preset time has elapsed since the key was turned off.

3. A vehicle body, a driver's cab provided at a front portion of the vehicle body and capable of ascending and descending relative to the vehicle body; A loading device provided in the driver's cab; A head guard provided above the driver's cab; a guide bar provided on the head guard to enable the hook portion of the safety belt to be hung; a detection sensor for detecting the presence or absence of the hook portion on the guide bar, an alarm that notifies an abnormality based on the presence or absence of the hook portion in the guide bar; a controller connected to the detection sensor and controlling the notification body, the controller controls the notifying body to notify that an abnormality has occurred in the safety belt when the hook portion is detected by the detection sensor when the key is turned off from the key-on state and when the hook portion is detected by the detection sensor when the key is turned on again from the key-off state; The loading vehicle is characterized in that the detection sensor detects the presence or absence of the hook portion on the guide bar while the key is in an off state.

4. A loading and unloading vehicle as described in any one of claims 1 to 3, characterized in that when the hook portion is detected by the detection sensor when the key is turned off, and when the hook portion is detected by the detection sensor after the key is turned on and an abnormality in the safety belt is reported, the controller releases the abnormality in the safety belt by removing the hook portion from the guide bar.

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