cargo handling vehicle

Abstract

To provide a cargo handling vehicle which can prevent erroneous discrimination of the presence or absence of a hook section of a safety belt when the hook section is suspended from a guide bar.SOLUTION: A cargo handling vehicle includes: a vehicle body; a control platform which is provided in a front section of the vehicle body and can be lifted with respect to the vehicle body; a cargo handling device which is provided in the control platform; and a head guard 35 which is provided above the control platform. The cargo handling vehicle further includes: a guide bar 45 which is provided in the head guard 35 and allows suspension of a hook section 51 of a safety belt 50 and movement of the hook section 51 in one direction; a photoelectric sensor 60 which optically detects the hook section 51 in the guide bar 45; and a controller which discriminates the presence or absence of the hook section 51 in the guide bar 45 by the detection of the photoelectric sensor 60. The guide bar 45 has a hook support section for supporting the hook section 51 so that the hook section 51 is not deviated from an optical axis of sensor light from the photoelectric sensor 60 even if the hook section swings with respect to the guide bar 45.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] A known example of prior art cargo handling vehicles is the picking forklift disclosed in Patent Document 1. The picking forklift disclosed in Patent Document 1 has a safety belt fastening device that fastens a safety belt worn by an operator who sits in a driver's compartment that can move up and down together with the forks of the picking forklift. The safety belt fastening device includes a safety bar that fastens the safety belt, 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 hook of the safety belt blocks the light from the light-emitting part of the optical sensor, detecting 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-emitting part of the optical sensor is not blocked, detecting that the safety belt is not fastened, and activating a red light and an audio alarm. Therefore, the safety belt fastening device of Patent Document 1 detects whether the safety belt is fastened to the safety belt fastening part, and sounds an alarm when the safety belt is not fastened. This prevents workers in the operator's cabin of the picking forklift from forgetting to fasten their safety belts and also urges them to fasten their safety belts. [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, in a cargo handling vehicle such as the picking forklift of Patent Document 1, when the hook portion of the safety belt tilts relative to the guide bar (safety bar), the sensor light of the photoelectric sensor may not be blocked, resulting in the erroneous determination that the hook portion is not on the guide bar. Furthermore, if the hook portion momentarily lifts up due to vibrations during travel, the hook portion may also be erroneously determined to be not on the guide bar. If the safety belt is erroneously determined to be not connected to the guide bar, an alarm may be sounded even though the safety belt is connected to the guide bar. Furthermore, if the cargo handling vehicle is controlled to restrict its operation in addition to issuing an alarm, the operation restriction significantly reduces work efficiency.

[0006] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a cargo handling vehicle that can prevent erroneous determination of the presence or absence of a hook portion of a safety belt when the hook portion is suspended from a guide bar. [Means for solving the problem]

[0007] In order to solve the above problems, a cargo handling vehicle having a vehicle body, a driver's cab provided at the front of the vehicle body and capable of rising and falling relative to the vehicle body, a cargo handling tool provided on the driver's cab, and a head guard provided above the driver's cab, is provided with: a guide bar provided on the head guard and enabling the suspension of a hook portion of a safety belt and the movement of the hook portion in one direction; a photoelectric sensor that optically detects the hook portion on the guide bar; and a controller that determines the presence or absence of the hook portion on the guide bar based on the detection by the photoelectric sensor, and the guide bar has a hook support portion that supports the hook portion so that it does not deviate from the optical axis of sensor light from the photoelectric sensor even when the hook portion swings relative to the guide bar. The guide bar has a plurality of guide members arranged substantially parallel to each other, and the plurality of guide members form the hook support portion that supports the hook portion at two or more points. It is characterized by:

[0008] In the present invention, the hook support portion of the guide bar supports the hook portion so that it does not deviate from the optical axis of the sensor light from the photoelectric sensor even if the hook portion swings relative to the guide bar. This allows the photoelectric sensor to reliably detect the hook portion on the guide bar, and prevents erroneous detection by the photoelectric sensor due to swinging of the hook portion relative to the guide bar. As a result, when the hook portion is suspended from the guide bar, the controller can reliably determine whether the hook portion is present or not. The plurality of guide members form a hook support portion that supports the hook portion at two or more points. In other words, by using the plurality of guide members, it is possible to realize a hook support portion that prevents the hook portion from deviating from the optical axis of the sensor light from the photoelectric sensor even when the hook portion swings relative to the guide bar.

[0009] In addition, in the above-mentioned loading vehicle, the photoelectric sensor may be provided on the head guard so that the sensor light is projected along the guide bar, and a cover member that covers the upper part of the sensor light may be provided on the head guard. In this case, the cover member covers the upper part of the sensor light, preventing the photoelectric sensor from malfunctioning due to receiving sunlight, and making it possible to reliably determine whether or not the hook portion is present on the guide bar regardless of whether the device is being operated indoors or outdoors.

[0010] In addition, in the above-mentioned loading and unloading vehicle, the guide bar may have a plurality of guide members arranged approximately parallel to each other, and the plurality of guide members may be configured to form the hook support portion that supports the hook portion at two or more points. In this case, the multiple guide members form a hook support portion that supports the hook portion at two or more points. In other words, by using multiple guide members, it is possible to realize a hook support portion that prevents the hook portion from deviating from the optical axis of the sensor light from the photoelectric sensor even if the hook portion swings relative to the guide bar.

[0011] The cargo handling vehicle may be configured to include an intervening member that fills the space between the plurality of guide members. In this case, since the intervening member fills the gaps between the multiple guide members, when the hook portion of the safety belt is hung on the guide bar, the hook portion does not get caught between the guide members, and the hook portion can be hung properly on the guide bar.

[0013] Furthermore, in the above-mentioned loading and unloading vehicle, the photoelectric sensor may have a light-emitting unit that emits sensor light from one end of the guide bar to the other end, and a light-receiving unit that receives the sensor light at the other end of the guide bar, and the controller may be configured to determine that the hook unit is on the guide bar when the sensor light is blocked by the hook unit, determine that the hook unit is not on the guide bar when the light-receiving unit receives the sensor light, and determine that the hook unit is on the guide bar when the light-receiving unit receives the sensor light after the sensor light is blocked by the hook unit, unless a preset time has elapsed after receiving the sensor light. In this case, even if the hook portion momentarily lifts off the guide bar due to vibrations during travel or the like and the light-receiving unit receives the sensor light without blocking the sensor light, it will not immediately be erroneously determined that the hook portion is not on the guide bar. In other words, even if the hook portion momentarily lifts off the guide bar and the light-receiving unit receives the sensor light without blocking the sensor light, it will be determined that the hook portion is on the guide bar unless a preset time has passed since the sensor light was received. Therefore, every time the hook portion momentarily lifts off the guide bar, it will not be erroneously determined that the hook portion is not on the guide bar, and an alarm will not be issued. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a cargo handling vehicle that can prevent erroneous determination of the presence or absence of a hook portion when the hook portion of a safety belt is suspended from a guide bar. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a side view of an order-picking forklift according to a first embodiment. FIG. [Figure 2] 1 is a perspective view of an order-picking forklift according to a first embodiment. FIG. [Figure 3] FIG. 2 is a perspective view of a main part of the head guard as viewed from above. [Figure 4] FIG. 2 is a perspective view of a main part of the head guard as viewed from below. [Figure 5] FIG. 2 is a longitudinal cross-sectional view of the guide bar. [Figure 6] (a) is a side view of the main part showing the state in which the hook part is naturally suspended from the guide bar, (b) is a side view of the main part showing the state in which the lower part of the hook part is inclined toward the rear, and (c) is a side view of the main part showing the state in which the lower part of the hook part is inclined toward the front. [Figure 7] FIG. 10 is a side view of the main part showing a state in which the hook portion is lifted up from the guide bar. [Figure 8] FIG. 10 is a perspective view showing a main part of a guide bar according to a second embodiment. [Figure 9] FIG. 10 is a vertical cross-sectional view of a guide bar according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] (First embodiment) A cargo handling vehicle according to a first embodiment will be described below with reference to the drawings. The cargo handling vehicle of this embodiment is an order-picking forklift. The terms "front / back," "left / right," and "up / down" that specify directions are shown 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.

[0017] 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 body 11, and front wheels 12 are provided at the front of the body 11. The front wheels 12 are drive wheels driven by an electric motor (not shown) for traveling housed in the body 11, and are also steerable wheels that can be steered by a steering device (not shown), and are located near the center in the left-right direction of the body 11. A pair of left and right legs 13 extending rearward are provided at the rear of the body 11, and rear wheels 14 are provided at the tips of the legs 13. The rear wheels 14 are rollable driven wheels.

[0018] The forklift 10 has a mast assembly 15. The mast assembly 15 is provided at the rear of the vehicle body 11 and includes a mast 16 and a driver's cab 17 that can be raised and lowered relative to the mast 16. The mast 16 has an outer mast 18 and an inner mast 19 that can be raised and lowered relative to the outer mast 18. The mast assembly 15 is provided with a lift cylinder 21 that raises and lowers the inner mast 19 relative to the outer mast 18. The upper end of a rod 21B provided on the lift cylinder 21 is connected to the upper end of the inner mast 19.

[0019] A sprocket 22 around which a chain 23 is hung is provided at the upper end of the inner mast 19. The cab 17 is suspended by the chain 23. The inner mast 19 moves up and down relative to the outer mast 18 as the rod 21B of the lift cylinder 21 extends and retracts relative to the cylinder body 21A, thereby moving the cab 17 up and down.

[0020] Next, the cab 17 will be described. As shown in FIG. 2, the cab 17 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 17. The forks 24 extend rearward from the bottom of the cab 17. A pair of left and right pillars 25 are erected in front of the cab 17. The pillars 25 support a head guard 35, which will be described later. A front wall 26 is erected from the cab 17 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.

[0021] As shown in FIG. 2, an instrument panel 28 is provided on the front wall 26. The instrument panel 28 is equipped with a steering wheel 29, an operating lever 30, various operating switches 31, and a warning buzzer 32. The cab 17 is equipped with operating pedals 33. The steering wheel 29 is operated by the operator when changing direction while traveling. The operating lever 30 raises and lowers the cab 17 and also serves to operate the accelerator when moving the forklift 10 forward or backward. A pair of left and right side gates 34 are provided near the top of the front wall 26 to protect the operator. The side gates 34 are L-shaped gate bars that can be moved up and down and are fixed in a retracted position, where they are rotated upward, and a guard position, where they are rotated downward. FIG. 1 shows the side gates 34 in the guard position, and FIG. 2 shows the side gates 34 in the retracted position.

[0022] Here, the head guard 35 will be described. As shown in FIG. 3 , the head guard 35 includes a frame body 36, a plurality of horizontal partition members 37 that divide the space defined by the frame body 36 into front and rear sections, and a vertical partition member 38 that divides the space defined by the frame body 36 into left and right sections. The frame body 36 includes a front plate portion 39, a rear plate portion 41, and a pair of left and right side plate portions 42. The front plate portion 39 extends in the left-right direction and is located in front of the frame body 36. The rear plate portion 41 extends in the left-right direction and is located in the rear of the frame body 36. The side plate portions 42 extend in the front-rear direction between and are connected to the ends of the front plate portion 39 and the rear plate portion 41. A pair of left and right reinforcing plates 43 is provided between the rear plate portion 41 and the rearmost horizontal partition member 37, and the reinforcing plates 43 are connected to the rear plate portion 41 and the rearmost horizontal partition member 37. For ease of explanation, most of the rear plate portion 41 is omitted in FIG.

[0023] As shown in Figures 3 and 4, the head guard 35 is equipped with a guide bar 45 for suspending a hook portion 51 of a safety belt 50 worn by the operator when boarding the cab 17. 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 45, 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 is equipped with 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. After the stopper body 55 is pushed in and the hook main body 54 is hooked onto the guide bar 45, when the stopper body 55 returns to its original position, the hook portion 51 will not come off the guide bar 45.

[0024] The guide bar 45 of this embodiment is provided in the head guard 35 between the rear plate portion 41 and the rearmost horizontal partition member 37. The guide bar 45 allows the hook portion 51 to move back and forth in one direction. The guide bar 45 of this embodiment has multiple guide members 46, 47 arranged approximately parallel to each other. The guide members 46, 47 are round metal bars. As shown in FIG. 5 , the guide member 46 has a pair of left and right end portions 46A, a pair of left and right inclined portions 46B, and a guide portion 46C extending in the left-right direction. The end portion 46A of the guide member 46 is fixed to the plate surface of the rearmost horizontal partition member 37. The inclined portion 46B extends slightly diagonally downward from the end portion 46A toward the rear. The guide portion 46C extends in the left-right direction between the pair of left and right inclined portions 46B.

[0025] The guide member 47 has a pair of left and right end portions 47A, a pair of left and right inclined portions 47B, and a guide portion 47C extending in the left-right direction. The end portions 47A are fixed to the plate surface of the rear plate portion 41. The inclined portions 47B each extend diagonally downward and slightly rearward from the end portions 47A. The guide portion 47C extends in the left-right direction between the pair of left and right inclined portions 47B. The guide portion 47C is located below the rear plate portion 41.

[0026] The guide portions 46C and 47C are disposed substantially parallel to each other and are at substantially the same height. Therefore, the guide portions 46C and 47C are positioned below the head guard 35. The guide portions 46C and 47C are disposed side by side in the front-to-rear direction relative to the vehicle body 11. The front-to-rear positions of the guide portions 46C and 47C are set so that the helmet (not shown) worn by the operator is unlikely to interfere with the hook portion 51. The distance between the guide portions 46C and 47C is set based on the shape of the hook portion 51 of the safety belt 50. Specifically, the guide portion 46C of the guide member 46 and the guide portion 47C of the guide member 47 support the hook portion 51 at two points. Therefore, the two guide members 46, 47 form a hook support portion that supports the hook portion 51 at two points using the guide portions 46C, 47C.

[0027] A metal plate member 48 is provided on guide members 46 and 47 to connect guide portion 46C and guide portion 47C. Plate member 48 corresponds to an intervening member that fills the space between guide members 46 and 47. By providing plate member 48, when hook portion 51 is hooked onto guide bar 45, hook portion 51 is prevented from being hooked onto only one of guide members 46 and 47.

[0028] 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 45. As shown in FIG. 3, the photoelectric sensor 60 has a light-emitting unit 62 that emits sensor light L and a light-receiving unit 61 that receives the emitted sensor light L. The light-emitting unit 62 is attached to a cover member 66 (described later) via a light-emitting-side bracket 64 that is bent into an L-shape. The light-emitting unit 62 is located to the right of the guide members 46, 47, and the optical axis of the sensor light L emitted from the light-emitting unit 62 is aligned with the longitudinal direction of the guide members 46C, 47C. The light-emitting unit 62 and the light-receiving unit 61 are positioned so as not to protrude rearward from the rear plate portion 41 of the head guard 35 in the front-to-rear direction, making them less likely to interfere with other objects and more easily protected (see FIG. 5).

[0029] The optical axis of the sensor light L is positioned slightly above and between the guide members 46C and 47C, so that it will not deviate from the optical axis even if the hook portion 51 swings back and forth while suspended from the guide members 46 and 47. The light-receiving portion 61 is mounted on the rearmost cover member 66 (described later) via an L-shaped light-receiving bracket 63. The light-receiving portion 61 is located to the left of the guide members 46 and 47 and is positioned so that it can receive the sensor light L emitted from the light-emitting portion 62. The left and right positions of the light-emitting portion 62 and the light-receiving portion 61 relative to the guide members 46 and 47 may be changed. The photoelectric sensor 60 may also be a diffuse reflection type photoelectric sensor in which the light-emitting portion 62 and the light-receiving portion 61 are integrated. In this case, a reflector (e.g., a mirror) that reflects the sensor light L is installed on the opposite side of the guide members 46 and 47.

[0030] The light-emitting unit 62 and the light-receiving unit 61 are connected to a controller 65 mounted on the vehicle body 11. The light-emitting unit 62 always emits sensor light L when the forklift 10 is being operated. When the light-receiving unit 61 receives the sensor light L, it transmits a signal indicating that the sensor light L has been received to the controller 65. When the light-receiving unit 61 does not receive the sensor light L, it transmits a signal indicating that the sensor light L has not been received to the controller 65.

[0031] When the light receiving unit 61 receives the sensor light L, it is determined that the hook portion 51 is not suspended from the guide bar 45, and the controller 65 issues a warning using the warning buzzer 32 and restricts the operation of the forklift 10. When the light receiving unit 61 does not receive the sensor light L, it is determined that the hook portion 51 is suspended from the guide bar 45 because the sensor light L is blocked, and the controller 65 does not issue a warning or restrict operation. The operation restrictions include, for example, restricting the lowering of the cab 17 and traveling at low speeds below a predetermined height.

[0032] In this embodiment, when hook portion 51 is suspended from guide bar 45, controller 65 does not issue a warning or restrict operation even if hook portion 51 momentarily lifts off guide bar 45 due to vibration or other causes and sensor light L is not blocked. When light receiving portion 61 receives sensor light L after sensor light L is blocked, controller 65 determines that hook portion 51 is on guide bar 45 unless a preset time has elapsed since receiving sensor light L. The set time is, for example, 0.5 seconds.

[0033] The head guard 35 of this embodiment has a metal cover member 66 that covers the guide bar 45, the light-emitting unit 62, and the light-receiving unit 61 from above. The cover member 66 has a cover main body 66A, a pair of left and right mounting portions 66B, and a pair of left and right mounting portions 66C. The mounting portions 66B extend downward from the cover main body 66A and are attached to the horizontal partition member 37 with bolts 67. The mounting portions 66C extend downward from the cover main body 66A. The light-emitting bracket 64 is attached to the right mounting portion 66C with bolts 68, and the light-receiving bracket 63 is attached to the left mounting portion 66C with bolts 68. The cover member 66 covers the upper side of the sensor light L of the photoelectric sensor 60, thereby preventing erroneous detection by the photoelectric sensor 60 due to strong sunlight.

[0034] Next, detection of the hook portion 51 in the forklift 10 according to this embodiment will be described. When an operator operates the forklift 10, if the hook portion 51 of the safety belt 50 is not suspended from the guide bar 45, the forklift 10 will issue a warning and restrict operation. As shown in FIG. 6(a), when the hook portion 51 is suspended from the guide bar 45, the hook portion 51 is supported at two points by the guide members 46 and 47 of the guide bar 45, and the sensor light L is blocked by the hook body 54 of the hook portion 51. Therefore, the controller 65 determines that the hook portion 51 is suspended from the guide bar 45, and does not issue a warning or restrict operation.

[0035] 6(b), for example, when rope portion 52 is pulled rearward and hook portion 51 is tilted so that the lower portion of hook portion 51 faces rearward, sensor light L is blocked by hook body 54 of hook portion 51. Therefore, controller 65 determines that hook portion 51 is suspended from guide bar 45, and does not issue a warning or restrict operation.

[0036] As shown in FIG. 6(c), for example, when rope portion 52 is pulled forward and hook portion 51 is tilted so that the lower portion of hook portion 51 faces forward, sensor light L is blocked by hook body 54 of hook portion 51. Therefore, controller 65 determines that hook portion 51 is suspended from guide bar 45 and does not issue a warning or restrict operation. In this way, even if hook portion 51 swings back and forth relative to guide bar 45, sensor light L is always blocked by hook body 54 of hook portion 51. Note that the swinging back and forth of hook portion 51 can occur not only when rope portion 52 is pulled, but also due to vibrations during travel and inertial forces during acceleration or deceleration.

[0037] Furthermore, as shown in Figure 7, it is possible that the hook portion 51 may momentarily rise from the guide bar 45 due to vibrations during travel or the like, and the sensor light L may not be blocked. In Figure 7, the hook portion 51 that momentarily rises from the guide bar 45 is indicated by a solid line, and the hook portion 51 that is supported at two points on the guide bar 45 is indicated by a two-dot chain line. Because the rise of the hook portion 51 is momentary, the time during which the sensor light L is not blocked is also momentary. For this reason, the controller 65 determines that the hook portion 51 is still hanging from the guide bar 45 because the preset time has not elapsed since the blocking of the sensor light L was released, and does not issue a warning or restrict operation.

[0038] The forklift 10 according to this embodiment has the following advantages. (1) Guide members 46, 47 forming the hook support portion of guide bar 45 support hook portion 51 so that it does not deviate from the optical axis of sensor light L from photoelectric sensor 60 even when hook portion 51 swings back and forth relative to guide bar 45. This allows photoelectric sensor 60 to reliably detect hook portion 51 on guide bar 45, and does not result in erroneous detection by photoelectric sensor 60 due to swinging of hook portion 51 relative to guide bar 45. As a result, when hook portion 51 is suspended from guide bar 45, controller 65 can reliably determine whether or not hook portion 51 is present.

[0039] (2) The photoelectric sensor 60 is provided on the head guard 35 so that the sensor light L of the photoelectric sensor 60 is projected along the guide bar 45, and a cover member 66 that covers the upper part of the sensor light L of the photoelectric sensor 60 is provided on the head guard 35. Therefore, because the cover member 66 covers the upper part of the sensor light L, it is possible to prevent the photoelectric sensor 60 from malfunctioning due to, for example, receiving sunlight, and it is possible to reliably detect the presence or absence of the hook portion 51 on the guide bar 45 regardless of whether the sensor is operated indoors or outdoors.

[0040] (3) Guide bar 45 has guide members 46 and 47 arranged approximately parallel to each other, and guide members 46 and 47 form a hook support portion that supports hook portion 51 at two points. In other words, by using guide members 46 and 47, it is possible to realize a hook support portion that does not deviate from the optical axis of sensor light L from photoelectric sensor 60 even if hook portion 51 swings back and forth relative to guide bar 45.

[0041] (4) The guide bar 45 is provided with a plate member 48 as an intervening member that fills the space between the guide members 46, 47. Since the plate member 48 fills the space between the guide members 46, 47, when the hook portion 51 of the safety belt 50 is suspended from the guide bar 45, the hook portion 51 does not get caught between the guide members 46, 47, and the hook portion 51 can be properly suspended from the guide bar 45.

[0042] (5) Photoelectric sensor 60 has light-emitting unit 62 that emits sensor light L from one end of guide bar 45 to the other end, and light-receiving unit 61 that receives sensor light L at the other end of guide bar 45. When sensor light L is blocked by hook portion 51, controller 65 determines that hook portion 51 is on guide bar 45, and when light-receiving unit 61 receives sensor light L, determines that hook portion 51 is not on guide bar 45. When light-receiving unit 61 receives sensor light L after sensor light L is blocked by hook portion 51, controller 65 determines that hook portion 51 is on guide bar 45 unless a preset time has elapsed since receiving sensor light L. For this reason, even if hook portion 51 momentarily lifts off guide bar 45 due to vibrations during driving or the like, and light-receiving unit 61 receives sensor light without blocking the sensor light, controller 65 will not immediately erroneously determine that hook portion 51 is not on guide bar 45. In other words, unless a preset time has elapsed since light reception, it is determined that hook portion 51 is present on guide bar 45. Therefore, every time hook portion 51 momentarily lifts off guide bar 45, it is not erroneously determined that hook portion 51 is absent and an alarm is not issued.

[0043] (Second embodiment) Next, a forklift according to a second embodiment will be described. The forklift according to this embodiment differs from the first embodiment in the configuration of the guide bar. In this embodiment, the same configuration as in the first embodiment will be referred to and the same reference numerals will be used.

[0044] As shown in FIG. 8, the guide bar 71 included in the forklift 70 of this embodiment has a single guide member 72 that supports the hook portion 51. The guide member 72 has a pair of left and right mounting support portions 73 and a guide portion 74 that extends in the left-right direction between the mounting support portions 73. The mounting support portion 73 is generally trapezoidal and is formed by bending both ends of the guide portion 74. Ends of the mounting support portion 73 are fixed to the rear panel portion 41 and the rearmost horizontal partition member 37. An opening 75 is formed in the mounting support portion 73 in alignment with the optical axis of the sensor light L so that the sensor light L can pass through.

[0045] The guide portion 74 corresponds to the hook support portion, and is plate-shaped with a cross section formed in a substantially arc shape. The guide portion 74 extends in the front-to-rear direction relative to the vehicle body 11. As shown in FIG. 9 , a surface 76 of the guide portion 74 is a support surface that supports the hook portion 51 when the hook portion 51 is suspended, and is set to have a curvature that is substantially the same as the curvature of the inner arc-shaped edge of the hook main body 54. In other words, the guide portion 74 is formed following the shape of the hook portion 51. Therefore, the guide portion 74 is capable of supporting the hook portion 51 at least at two or more points.

[0046] This embodiment provides the same advantages as the advantages (1) and (2) of the first embodiment. Furthermore, in this embodiment, guide bar 71 has a single guide member 72, which reduces the number of parts compared to a guide bar using multiple guide members, thereby reducing the manufacturing cost of the guide bar.

[0047] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.

[0048] In the above embodiment, 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. In the above embodiment, the head guard is provided with a cover member that covers the upper portion of the sensor light from the photoelectric sensor, but the present invention is not limited to this. The cover member is not an essential component, and for example, if the vehicle is used indoors, it is not necessary to provide the head guard with a cover member. In the first embodiment, two guide members are used as the plurality of guide members to support the hook member at two points. However, this is not limiting. For example, three guide members may be used to support the hook member at three points or two points, and any number of guide members may be used. Furthermore, the plurality of guide members are not limited to round bars and may be plate materials, and the cross-sectional shape may be any desired shape. In the first embodiment, an intervening member is provided to fill the space between the guide members, but this is not limiting. The intervening member is not an essential requirement, and even in the case of a plurality of guide members, no intervening member may be provided. [Explanation of symbols]

[0049] 10, 70 forklift 11 Body 12 Front wheels 13th Leg 14 rear wheels 15 Mast equipment 17 Driver's cab 24 Fork 32 Warning buzzer (alarm device) 33 Operation pedal 35 Head Guard 45, 71 Guide bar 46, 47, 72 Guide members 46C, 47C, 74 guide part 48 Plate member 50 Safety Belt 51 Hook part 60 Photoelectric Sensor 61 Light receiving section 62 Light projector 65 Controller 66 Cover member L Sensor light (optical axis)

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 cargo handling vehicle having a head guard provided above the driver's cab, a guide bar provided on the head guard for suspending the hook portion of the safety belt and for allowing the hook portion to move in one direction; a photoelectric sensor that optically detects the hook portion of the guide bar; a controller that determines the presence or absence of the hook portion on the guide bar based on detection by the photoelectric sensor, the guide bar has a hook support portion that supports the hook portion so that the hook portion does not deviate from the optical axis of the sensor light from the photoelectric sensor even when the hook portion swings relative to the guide bar, The guide bar has a plurality of guide members arranged substantially parallel to one another, The plurality of guide members form the hook support portion that supports the hook portion at two or more points.

2. the photoelectric sensor is provided on the head guard so that the sensor light is projected along the guide bar, 2. The cargo handling vehicle according to claim 1, wherein a cover member for covering the upper part of the sensor light is provided on the head guard.

3. A loading and unloading vehicle as described in claim 1 or 2, characterized in that an intervening member is provided to fill the space between the multiple guide members.

4. The photoelectric sensor a light projecting unit that emits the sensor light from one end of the guide bar to the other end; a light receiving portion at the other end of the guide bar that receives the sensor light, The controller When the sensor light is blocked by the hook portion, it is determined that the hook portion is present on the guide bar; When the light receiving unit receives the sensor light, it determines that the hook portion is not on the guide bar, A loading vehicle as described in claim 1 or 2, characterized in that when the light receiving unit receives the sensor light after the sensor light is blocked by the hook portion, it determines that the hook portion is on the guide bar unless a predetermined set time has elapsed after the sensor light is received.

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