Vehicle approach warning device and picking truck equipped with said device

Abstract

To provide a vehicle approach notification device not giving discomfort to people around when a lighting state of an illumination unit changes, and a picking truck.SOLUTION: The vehicle approach notification device comprises: a first illumination unit that is provided in a liftable driver stand of a vehicle and that emits first notification light toward the rear road surface of the vehicle; a second illumination unit that is provided in an unliftable body of the vehicle and that emits second notification light toward the road surface; and a control unit that lights the first illumination unit while turning off the second illumination unit when the lifting position H of the driver stand is less than a prescribed threshold value Hth, and turns off the first illumination unit while lighting the second illumination unit when the lifting position H is equal to or greater than the threshold value Hth. The control unit executes change control for illumination states of the first and second illumination units when the lifting position becomes less than the threshold value Hth and equal to or greater than the threshold value Hth after the elapse of predetermined delay time td.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a vehicle approach warning device that warns people in the vicinity of an approaching vehicle by shining light toward a road surface around the vehicle, and to a picking truck equipped with said device. [Background technology]

[0002] Conventionally, a picking truck equipped with a vehicle approach notification device including a first illumination unit and a second illumination unit is known (for example, see Patent Document 1). The first illumination unit is provided in a driver's cab that can be raised and lowered, and is turned on when the driver's cab is lower than a predetermined threshold, i.e., at a low lift height, and irradiates a first notification light toward the road surface behind the vehicle. On the other hand, the second illumination unit is provided in a vehicle body that cannot be raised and lowered, and is turned on when the driver's cab is equal to or higher than the threshold, i.e., at a high lift height, and irradiates a second notification light toward the road surface behind the vehicle. According to this vehicle approach notification device and picking truck, when the first notification light of the first illumination unit is at a high lift height where it cannot sufficiently reach the road surface, the second illumination unit irradiates the second notification light toward the road surface instead of the first illumination unit, so that it is possible to reliably notify people in the vicinity of the approach of a vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6984987 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-mentioned conventional vehicle approach warning device and picking truck, a so-called chattering phenomenon occurs in which the first lighting unit and the second lighting unit repeatedly flash immediately after the driver's cab is raised and its raised / lowered position exceeds the threshold value, and immediately after the driver's cab is lowered and its raised / lowered position falls below the threshold value, causing discomfort to people in the vicinity.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and its objective is to provide a vehicle approach warning device and a picking truck that do not cause discomfort to people in the vicinity when the lighting state of the lighting unit is changed. [Means for solving the problem]

[0006] In order to solve the above problem, the vehicle approach warning device of the present invention includes a first lighting unit provided in a driver's cab that can be raised and lowered of the vehicle, and irradiating a first warning light toward a road surface behind the vehicle; a second lighting unit provided in a vehicle body that cannot be raised and lowered, and irradiating a second warning light toward the road surface; and a control unit that turns on the first lighting unit and turns off the second lighting unit when the raised or lowered position of the driver's cab is below a predetermined threshold, and turns off the first lighting unit and turns on the second lighting unit when the raised or lowered position is equal to or greater than the threshold, and is characterized in that the control unit executes control to change the lighting state of the first lighting unit and the second lighting unit when the raised or lowered position is below the threshold, and control to change the lighting state of the first lighting unit and the second lighting unit when the raised or lowered position is equal to or greater than the threshold, after a predetermined delay time has elapsed.

[0007] It is preferable that the delay time of the vehicle approach warning device is set so as to become shorter as the raising / lowering speed of the driver's cab increases.

[0008] It is preferable that the delay time of the vehicle approach warning device is set to a first delay time when the speed of ascent and descent of the driver's seat is less than a predetermined first speed threshold, and to a second delay time shorter than the first delay time when the speed of ascent and descent is equal to or greater than the first speed threshold.

[0009] It is preferable that the delay time of the vehicle approach warning device is set to a second delay time when the speed of ascent and descent of the driver's seat is less than a predetermined second speed threshold, and to a third delay time shorter than the second delay time when the speed of ascent and descent is equal to or greater than the second speed threshold.

[0010] The first and second illumination sections of the vehicle approach warning device are preferably provided such that axes of the first and second alert lights intersect on the road surface when the elevation position is equal to the threshold value.

[0011] It is preferable that the color of the second alert light of the vehicle approach alert device is different from the color of the first alert light.

[0012] In addition, in order to solve the above-mentioned problems, the picking truck of the present invention comprises a vehicle body having a running device, a mast provided at the rear of the vehicle body, a driver's cab that can be raised and lowered along the mast, a first lighting unit provided at the driver's cab that irradiates a first alert light toward a road surface behind the vehicle, a second lighting unit provided at the vehicle body that irradiates a second alert light toward the road surface, and a control unit that turns on the first lighting unit and extinguishes the second lighting unit when the lifted position of the driver's cab is below a predetermined threshold, and turns off the first lighting unit and turns on the second lighting unit when the lifted position is equal to or greater than the threshold, and is characterized in that the control unit executes control to change the lighting states of the first lighting unit and the second lighting unit when the lifted position is below the threshold, and control to change the lighting states of the first lighting unit and the second lighting unit when the lifted position is equal to or greater than the threshold, after a predetermined delay time has elapsed.

[0013] It is preferable that the delay time of the picking truck is determined so as to become shorter as the raising and lowering speed of the driver's cab increases.

[0014] It is preferable that the delay time of the picking truck is set to a first delay time when the ascent / descension speed of the cab is less than a predetermined first speed threshold, and to a second delay time shorter than the first delay time when the ascent / descension speed is equal to or greater than the first speed threshold.

[0015] It is preferable that the delay time of the picking truck is set to a second delay time when the ascent / descension speed of the cab is less than a predetermined second speed threshold, and to a third delay time shorter than the second delay time when the ascent / descension speed is equal to or greater than the second speed threshold.

[0016] The first and second illumination units of the picking truck are preferably provided such that axes of the first and second notification lights intersect on the road surface when the lifted / lowered position is equal to the threshold value.

[0017] It is preferable that the color of the second notification light of the picking truck is different from the color of the first notification light.

[0018] In this specification, the term "lighting" includes regular blinking that is designed not to cause discomfort to people in the vicinity. Effect of the Invention

[0019] According to the present invention, it is possible to provide a vehicle approach warning device and a picking truck that do not cause discomfort to people in the vicinity when the lighting state of the lighting unit is switched. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic side view of a picking truck according to a first embodiment of the present invention. [Diagram 2] 1 is a block diagram of a vehicle approach warning device according to a first embodiment. [Diagram 3] 6 is a graph showing the relationship between the lighting state and the illumination distance of each illumination unit and the lifting position in the first embodiment. [Figure 4] 1A is a schematic side view of a picking truck according to a first embodiment when it is at a low lifting height, and FIG. 1B is a schematic side view of a picking truck according to a first embodiment when it is at a high lifting height. [Diagram 5] 6 is a graph showing an example of changes over time in the lighting state and elevation position of each illumination unit in the first embodiment. [Figure 6] FIG. 5 is a block diagram of a vehicle approach warning device according to a second embodiment of the present invention. [Figure 7] 13 is a graph showing the relationship between the delay time and the ascending / descending speed in the second embodiment. [Figure 8]13 is a graph showing an example of changes over time in the lighting state and elevation position of each illumination unit in the second embodiment. [Figure 9] FIG. 11 is a block diagram of a vehicle approach warning device according to a third embodiment of the present invention. [Figure 10] 13 is a graph showing the relationship between the delay time and the ascending / descending speed in the third embodiment. [Figure 11] 13 is a graph showing an example of changes over time in the lighting state and elevation position of each illumination unit in the third embodiment. [Figure 12] FIG. 11 is a block diagram of a vehicle approach warning device according to a fourth embodiment of the present invention. [Figure 13] 13 is a graph showing the relationship between the delay time and the ascending / descending speed in the fourth embodiment. [Figure 14] 13 is a graph showing an example of changes over time in the lighting state and elevation position of each illumination unit in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a vehicle approach warning device and a picking truck according to the present invention will be described with reference to the accompanying drawings.

[0022] [First Example] A picking truck 10 according to a first embodiment of the present invention is shown in FIG. 1. As shown in the figure, the picking truck 10 according to this embodiment includes a vehicle body 11 having a traveling device, left and right legs 12, 12 and a mast 13 provided at the rear of the vehicle body 11, and a cab 14 that can be raised and lowered along the mast 13. The cab 14 also includes an operation panel 15 including various levers and the like operated by an operator, a fall guard 16 for preventing the operator from falling, a pair of left and right forks 17, 17 extending rearward, and a head guard 18 for covering the operator's head. The forks 17, 17 are provided on the floor plate of the cab 14.

[0023] The picking truck 10 according to this embodiment further includes a control unit 21A, a first illumination unit 22, a second illumination unit 23, and a lifting position detection unit 30, which constitute a vehicle approach warning device 20A.

[0024] The first illumination unit 22 is composed of an LED light that irradiates the first notification light L1 toward the road surface F behind the vehicle. The image of the first notification light L1 that appears on the road surface F may be a circle with a vague outline, or may be a spot, line, or arrow with a clear outline due to the action of a lens or slit provided in the first illumination unit 22. In addition, the color of the first notification light L1 is preferably a color that stands out against the road surface F in order to enhance the notification effect. In this embodiment, the color of the first notification light L1 is blue.

[0025] The first illumination unit 22 is provided at the rear end of the head guard 18 via a suitable bracket (not shown). The first illumination unit 22 is provided so that its irradiation direction (i.e., the axis of the first notification light L1) forms an angle θ1 with respect to the vertical line P.

[0026] The second illumination unit 23 is composed of an LED light that irradiates the second alert light L2 toward the road surface F behind the vehicle. The image of the second alert light L2 that appears on the road surface F may be a circle with a vague outline, or a spot, line, or arrow with a clear outline, similar to the image of the first alert light L1. In addition, the color of the second alert light L2 is preferably a color that stands out against the road surface F in order to enhance the alert effect, and is more preferably different from the color of the first alert light L1. In this embodiment, the color of the second alert light L2 is red.

[0027] The second illumination unit 23 is provided at the rear of the vehicle body 11 via a suitable bracket (not shown). The second illumination unit 23 is provided so that its irradiation direction (i.e., the axis of the second notification light L2) forms an angle θ2 (where θ2>θ1) with respect to the vertical line P.

[0028] As shown in FIG. 2, the control unit 21A is configured to change the lighting state of the first lighting unit 22 and the second lighting unit 23 depending on the elevation position H of the cab 14 detected by the elevation position detection unit 30.

[0029] In Fig. 1, the control unit 21A is provided inside the vehicle body 11, but the position of the control unit 21A can be changed arbitrarily. For example, the control unit 21A may be provided in the driver's cab 14. In Fig. 1, the lift position detection unit 30 is provided inside the vehicle body 11, but this position can also be changed arbitrarily.

[0030] Next, the operation of the picking truck 10 and the vehicle approach warning device 20A according to this embodiment will be described in more detail with particular reference to FIGS.

[0031] (1) When the lift position H is less than a predetermined threshold value Hth In this case, the control unit 21A turns on the first illumination unit 22 and turns off the second illumination unit 23. As a result, a blue image due to the first notification light L1 appears on the road surface F. Note that an example of "when the elevation position H is less than the threshold value Hth" is when the elevation position H shown in FIG. 5(A) is the lower limit value Hmin.

[0032] The distance D1 from the tip of the fork 17, 17 to the center of the image of the first notification light L1 is referred to as the "first irradiation distance." As shown in Fig. 3, the first irradiation distance D1 changes depending on the elevation position H. More specifically, the first irradiation distance D1 becomes longer as the elevation position H becomes higher.

[0033] In this embodiment, the threshold value Hth is 1 m. The threshold value Hth is set to a value such that the second notification light L2 is not blocked by the cab 14 when the elevation position H is equal to the threshold value Hth.

[0034] (2) When the lift position H is equal to or greater than a predetermined threshold Hth In this case, the control unit 21A turns off the first illumination unit 22 and turns on the second illumination unit 23. As a result, a red image by the second notification light L2 appears on the road surface F. Note that an example of "when the lift position H is equal to or greater than the threshold value Hth" is when the lift position H shown in FIG. 5(B) is the upper limit value Hmax.

[0035] The distance D2 from the tip of the fork 17, 17 to the center of the image of the second notification light L2 is called the "second irradiation distance." In this embodiment, the threshold value Hth and the angles θ1, θ2 are determined so that the first irradiation distance D1 and the second irradiation distance D2 are equal when the lift position H is equal to the threshold value Hth (see Figs. 1 and 3). That is, in this embodiment, when the lift position H is equal to the threshold value Hth, the axes of the first notification light L1 and the second notification light L2 intersect on the road surface F. This prevents the image of the notification light from moving instantaneously when the lift position H is equal to the threshold value Hth, causing people in the vicinity to lose sight of the image.

[0036] 3, in the picking truck 10 and the vehicle approach warning device 20A according to this embodiment, the second irradiation distance D2 does not change even if the lift position H changes between the threshold value Hth and the upper limit value Hmax. Therefore, the picking truck 10 and the vehicle approach warning device 20A according to this embodiment can always deliver sufficient warning light to the road surface F. In other words, the picking truck 10 and the vehicle approach warning device 20A can prevent a decrease in the warning effect when the vehicle is raised high.

[0037] Furthermore, in the picking truck 10 and vehicle approach warning device 20A according to this embodiment, the color of the image appearing on the road surface F changes depending on the lift position H. The operator of the picking truck 10 tends to have difficulty noticing people in the vicinity when the truck is elevated, but with the picking truck 10 and vehicle approach warning device 20A according to this embodiment, people in the vicinity can notice that the truck is elevated based on the color of the image appearing on the road surface F and become more vigilant around the picking truck 10, thereby being able to avoid contact with the picking truck 10.

[0038] In this way, when the elevation position H of the cab 14 is below the threshold value Hth, the control unit 21A turns on the first illumination unit 22 and turns off the second illumination unit 23, and when the elevation position H is equal to or greater than the threshold value Hth, the control unit 21A turns off the first illumination unit 22 and turns on the second illumination unit 23. However, when the elevation position H becomes less than the threshold value Hth and when it becomes equal to or greater than the threshold value Hth, the control unit 21A does not immediately execute control to change the illumination states of the first illumination unit 22 and the second illumination unit 23, but executes the control after a predetermined delay time td has elapsed, as shown in FIG.

[0039] That is, in this embodiment, when the lift position H becomes equal to or greater than the threshold Hth at time t1, the first illumination unit 22 switches from ON to OFF and the second illumination unit 23 switches from OFF to ON at the time when the delay time td has elapsed from time t1. Also, in this embodiment, when the lift position H becomes less than the threshold Hth at time t2, the first illumination unit 22 switches from OFF to ON and the second illumination unit 23 switches from ON to OFF at the time when the delay time td has elapsed from time t2. Therefore, according to the picking truck 10 and the vehicle approach warning device 20A of this embodiment, it is possible to prevent the first illumination unit 22 and the second illumination unit 23 from repeatedly blinking in an unpleasant manner, i.e., chattering, immediately after the lift position H becomes less than the threshold Hth and immediately after it becomes equal to or greater than the threshold Hth.

[0040] [Second Example] A vehicle approach warning device 20B according to a second embodiment of the present invention is shown in Fig. 6. The vehicle approach warning device 20B differs from the vehicle approach warning device 20A according to the first embodiment shown in Fig. 2 in that it includes a control unit 21B instead of the control unit 21A, but is otherwise common to the vehicle approach warning device 20A.

[0041] In addition, the picking truck according to the second embodiment of the present invention differs from the picking truck 10 according to the first embodiment shown in FIG. 1 in that it is equipped with a vehicle approaching warning device 20B instead of the vehicle approaching warning device 20A, but is common to the picking truck 10 in other respects.

[0042] The control unit 21B calculates the lifting speed VH of the cab 14 based on the lifting position H of the cab 14 detected by the lifting position detection unit 30. For example, when the lifting position detection unit 30 detects the lifting position H at a frequency of 20 times per second, the control unit 21B calculates the lifting speed VH by the following formula based on the latest lifting position H (e.g., H1) and the lifting position H detected 0.05 seconds ago (e.g., H2). VH=|(H1-H2) / 0.05|

[0043] Furthermore, the control unit 21B calculates the delay time td corresponding to the elevation speed VH calculated by the above formula based on the relationship between the predetermined delay time td and the elevation speed VH (see FIG. 7). In this embodiment, the delay time td is determined to become shorter as the elevation speed VH increases.

[0044] Then, when the lift position H becomes less than the threshold value Hth, or becomes equal to or greater than the threshold value Hth, the control unit 21B does not immediately execute control to change the lighting state of the first lighting unit 22 and the second lighting unit 23, but executes the control after a delay time td calculated from the relationship shown in FIG. 7 has elapsed.

[0045] The timing of the change control by the control unit 21B will be specifically described with reference to FIG.

[0046] (1) When the lift speed VH is the standard speed In this case, when the lift position H becomes less than the threshold value Hth, and when it becomes equal to or greater than the threshold value Hth, the control unit 21B executes control to change the lighting state of the first lighting unit 22 and the second lighting unit 23 after the delay time td2 has elapsed (see FIG. 8(B)).

[0047] (2) When the lift speed VH is relatively slow In this case, it is expected that the period during which chattering occurs is longer than when the lifting speed VH is standard. Therefore, when the lifting position H becomes less than the threshold value Hth and when it becomes equal to or greater than the threshold value Hth, the control unit 21B executes the control for changing the lighting state of the first lighting unit 22 and the second lighting unit 23 after a delay time td1 (where td1 > td2) has elapsed (see Fig. 8(A)).

[0048] (3) When the lifting speed VH is relatively high In this case, it is expected that the period during which chattering occurs is shorter than when the lifting speed VH is standard. Therefore, when the lifting position H becomes less than the threshold value Hth and when it becomes equal to or greater than the threshold value Hth, the control unit 21B executes the control for changing the lighting state of the first lighting unit 22 and the second lighting unit 23 after a delay time td3 (where td3 < td2) has elapsed (see Fig. 8(C)).

[0049] According to the picking truck and the vehicle approach notification device 20B according to the present embodiment, by executing the control for changing the lighting state of the first lighting unit 22 and the second lighting unit 23 as early as possible within the range where chattering does not occur, it is possible to prevent a decrease in the notification effect.

[0050] [Third Embodiment] Fig. 9 shows a vehicle approach notification device 20C according to the third embodiment of the present invention. The vehicle approach notification device 20C is different from the vehicle approach notification device 20A according to the first embodiment shown in Fig. 2 in that it includes a control unit 21C instead of the control unit 21A, but is common with the vehicle approach notification device 20A in other respects.

[0051] Further, the picking truck according to the third embodiment of the present invention is different from the picking truck 10 according to the first embodiment shown in Fig. 1 in that it includes a vehicle approach notification device 20C instead of the vehicle approach notification device 20A, but is common with the picking truck 10 in other respects.

[0052] The control unit 21C obtains the lifting speed VH of the driver's cab 14 in the same manner as the control unit 21B in the second embodiment.

[0053] Furthermore, the control unit 21C obtains a delay time td corresponding to the elevation speed VH based on a predetermined relationship between the delay time td and the elevation speed VH (see FIG. 10). In this embodiment, the delay time td is determined so as to change in a stepwise manner from td1 to td2 or from td2 to td1 when the elevation speed VH reaches the first speed threshold VHth1.

[0054] Then, when the lift position H becomes less than the threshold value Hth, or becomes equal to or greater than the threshold value Hth, the control unit 21C does not immediately execute control to change the lighting state of the first lighting unit 22 and the second lighting unit 23, but executes the control after a delay time td calculated from the relationship shown in FIG. 10 has elapsed.

[0055] The timing of the change control by the control unit 21C will be specifically described with reference to FIG.

[0056] (1) When the vertical speed VH is equal to or greater than the first speed threshold VHth1 In this case, when the lift position H becomes less than the threshold value Hth, and when it becomes equal to or greater than the threshold value Hth, the control unit 21C executes control to change the lighting state of the first lighting unit 22 and the second lighting unit 23 after the delay time td2 has elapsed (see Figures 11(B) and (C)).

[0057] (2) When the vertical speed VH is less than the first speed threshold VHth1 In this case, it is expected that the period during which chattering occurs is longer than in other cases. Therefore, when the elevation position H becomes less than the threshold value Hth and when it becomes equal to or greater than the threshold value Hth, the control unit 21C executes the change control of the lighting state of the first illumination unit 22 and the second illumination unit 23 after the delay time td1 (where td1>td2) has elapsed (see FIG. 11(A)).

[0058] According to the picking truck and vehicle approach notification device 20C of this embodiment, it is possible to obtain effects similar to those of the picking truck and vehicle approach notification device 20B of the second embodiment with simplified control.

[0059] [Fourth Example] A vehicle approach warning device 20D according to a fourth embodiment of the present invention is shown in Fig. 12. The vehicle approach warning device 20D differs from the vehicle approach warning device 20A according to the first embodiment shown in Fig. 2 in that it includes a control unit 21D instead of the control unit 21A, but is otherwise common to the vehicle approach warning device 20A.

[0060] In addition, the picking truck according to the fourth embodiment of the present invention differs from the picking truck 10 according to the first embodiment shown in FIG. 1 in that it is equipped with a vehicle approaching warning device 20D instead of the vehicle approaching warning device 20A, but is common to the picking truck 10 in other respects.

[0061] The control unit 21D obtains the lifting speed VH of the cab 14 in the same manner as the control unit 21B in the second embodiment and the control unit 21C in the third embodiment.

[0062] Furthermore, the control unit 21D obtains a delay time td corresponding to the elevation speed VH based on a predetermined relationship between the delay time td and the elevation speed VH (see FIG. 13). In this embodiment, the delay time td is determined to change in a stepwise manner from td2 to td3 or from td3 to td2 when the elevation speed VH becomes a second speed threshold VHth2 (where VHth2>VHth1).

[0063] Then, when the lift position H becomes less than the threshold value Hth, or becomes equal to or greater than the threshold value Hth, the control unit 21D does not immediately execute control to change the lighting state of the first lighting unit 22 and the second lighting unit 23, but executes the control after a delay time td calculated from the relationship shown in FIG. 13 has elapsed.

[0064] The timing of the change control by the control unit 21D will be specifically described with reference to FIG.

[0065] (1) When the vertical speed VH is less than the second speed threshold VHth2 In this case, when the lifting position H becomes less than the threshold value Hth and when it becomes equal to or greater than the threshold value Hth, the control unit 21D executes the control for changing the lighting states of the first lighting unit 22 and the second lighting unit 23 after the elapse of the delay time td2 (see FIGS. 14(A) and (B)).

[0066] (2) When the lifting speed VH is equal to or higher than the second speed threshold value VHth2 In this case, it is expected that the period during which chattering occurs is shorter than in the case where it is not so. For this reason, when the lifting position H becomes less than the threshold value Hth and when it becomes equal to or greater than the threshold value Hth, the control unit 21D executes the control for changing the lighting states of the first lighting unit 22 and the second lighting unit 23 after the elapse of the delay time td3 (where td3 < td2) (see FIG. 14(C)).

[0067] According to the picking truck and the vehicle approach notification device 20D according to the present embodiment, it is possible to obtain an effect similar to that of the picking truck and the vehicle approach notification device 20B according to the second embodiment with simplified control.

[0068] [Modification Example]

[0069] As described above, the first to fourth embodiments of the vehicle approach notification device and the picking truck according to the present invention have been described, but the configuration of the present invention is not limited to these.

[0070] For example, the relationships between the delay time td and the lifting speed VH shown in FIGS. 7, 10, and 13 are merely illustrative. In the present invention, the delay time td can be obtained based on an arbitrary relationship such that the delay time becomes shorter in two steps, three steps, ··· continuously as the lifting speed VH increases.

[0071] Further, the first lighting unit 22 may be provided at an arbitrary position on the driver's cab 14 (a position other than the rear end portion of the head guard 18).

[0072] Further, the first irradiation distance D1 and the second irradiation distance D2 do not necessarily have to coincide when the lifting position H is the threshold value Hth.

[0073] Furthermore, the color (blue) of the first alert light L1 and the color (red) of the second alert light L2 are merely examples. For example, in the present invention, the first alert light L1 and the second alert light L2 may have the same color.

[0074] The threshold value Hth(1 m) is also merely an example. [Explanation of symbols]

[0075] 10 Picking Truck 11 Vehicle body 12 Legs 13 Mast 14 Cab 15 Control panel 16 Fall guard 17. Fork 18 Head Guard 20A, 20B, 20C, 20D Vehicle approach warning device 21A, 21B, 21C, 21D Control section 22 First Lighting Section 23 Second Lighting Section 30 Lifting position detection unit

Claims

1. a first illumination unit provided in a driver's cab that can be raised and lowered of the vehicle and configured to emit a first notification light toward a road surface behind the vehicle; a second illumination unit provided on a vehicle body that cannot be raised or lowered of the vehicle and configured to irradiate a second notification light toward the road surface; a control unit that turns on the first illumination unit and turns off the second illumination unit when the elevation position of the cab is less than a predetermined threshold, and turns off the first illumination unit and turns on the second illumination unit when the elevation position is equal to or greater than the threshold; Equipped with the control unit executes, after a predetermined delay time has elapsed, control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is less than the threshold value, and control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is equal to or greater than the threshold value; The delay time is set to be shorter as the raising / lowering speed of the cab increases. A vehicle approach warning device comprising:

2. A first lighting unit provided in a driver's cab that can be raised and lowered of a vehicle, the first lighting unit irradiating a first notification light toward a road surface behind the vehicle; a second illumination unit provided on a vehicle body that cannot be raised or lowered of the vehicle and configured to irradiate a second notification light toward the road surface; a control unit that turns on the first illumination unit and turns off the second illumination unit when the elevation position of the cab is less than a predetermined threshold, and turns off the first illumination unit and turns on the second illumination unit when the elevation position is equal to or greater than the threshold; Equipped with the control unit executes, after a predetermined delay time has elapsed, control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is less than the threshold value, and control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is equal to or greater than the threshold value; The delay time is set to a first delay time when the ascent / descent speed of the cab is less than a predetermined speed threshold, and is set to a second delay time shorter than the first delay time when the ascent / descent speed is equal to or greater than the speed threshold. A vehicle approach warning device comprising:

3. The first illumination unit and the second illumination unit are provided such that axes of the first notification light and the second notification light intersect on the road surface when the elevation position is equal to the threshold value.

3. The vehicle approach warning device according to claim 1 or 2.

4. The color of the second notification light is different from the color of the first notification light.

3. The vehicle approach warning device according to claim 1 or 2.

5. A vehicle body having a running device; A mast provided at the rear of the vehicle body; A cab that can rise and fall along the mast; A first illumination unit provided in the cab and configured to emit a first notification light toward a road surface behind the vehicle; a second illumination unit provided on the vehicle body and configured to irradiate a second notification light toward the road surface; a control unit that turns on the first illumination unit and turns off the second illumination unit when the elevation position of the cab is less than a predetermined threshold, and turns off the first illumination unit and turns on the second illumination unit when the elevation position is equal to or greater than the threshold; Equipped with the control unit executes, after a predetermined delay time has elapsed, control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is less than the threshold value, and control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is equal to or greater than the threshold value; The delay time is set to be shorter as the raising / lowering speed of the cab increases. A picking truck characterized by:

6. A vehicle body having a running device, A mast provided at the rear of the vehicle body; A cab that can rise and fall along the mast; A first illumination unit provided in the cab and configured to emit a first notification light toward a road surface behind the vehicle; a second illumination unit provided on the vehicle body and configured to irradiate a second notification light toward the road surface; a control unit that turns on the first illumination unit and turns off the second illumination unit when the elevation position of the cab is less than a predetermined threshold, and turns off the first illumination unit and turns on the second illumination unit when the elevation position is equal to or greater than the threshold; Equipped with the control unit executes, after a predetermined delay time has elapsed, control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is less than the threshold value, and control to change the lighting states of the first lighting unit and the second lighting unit when the elevation position is equal to or greater than the threshold value; The delay time is set to a first delay time when the ascent / descent speed of the cab is less than a predetermined speed threshold, and is set to a second delay time shorter than the first delay time when the ascent / descent speed is equal to or greater than the speed threshold. A picking truck characterized by:

7. The first illumination unit and the second illumination unit are provided such that axes of the first notification light and the second notification light intersect on the road surface when the elevation position is equal to the threshold value.

7. The picking truck according to claim 5 or 6.

8. The color of the second notification light is different from the color of the first notification light.

7. The picking truck according to claim 5 or 6.

Images