Safety fence support structure and fall prevention device

Abstract

To provide a support structure for a safety fence for a vehicle, which has a simple structure, is robust and can be easily installed in an existing structure, and to provide a fall prevention device.SOLUTION: In a support structure for a safety fence, the safety fence 20 includes an upright member 24, a rotating shaft, an engaging member, a compression spring, a cable-like member, a support base 40; the support base has a rotating-shaft support portion and a to-be-engaged member; the to-be-engaged member includes a first engagement recessed portion, a second engagement recessed portion, and a connecting portion in which the engaging member moves; a disengaging mechanism 28 is disposed on the safety fence; one-end portion of the cable-like portion is wound around a movable winding portion 29 and a fixed winding portion in order after connected to a fixing connection portion of the disengaging function; and when a tensile force is applied to the other-end side, the movable winding portion moves, so that a force for disengaging the engaging member from the first engagement recessed portion or the second engagement recessed portion is applied to the engaging member.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a support structure for a safety fence installed on a gate plate that is arranged at an opening of a vehicle and raised and lowered between the ground surface and the floor surface inside the vehicle, and a fall prevention device installed on the support structure for the safety fence. [Background technology]

[0002] The bed of a truck, a vehicle used to transport cargo, is mounted on a chassis frame consisting of wheels, a ladder frame, a suspension mechanism, etc., so there is a significant difference in height between the floor of the vehicle and the ground, which makes it difficult to load and unload cargo.

[0003] In order to improve the workability of the above-mentioned loading and unloading operations and to reduce the burden on workers, a tailgate mechanism is known in which a gate plate used when loading cargo is raised and lowered between the ground and the floor of the loading platform. Such a gate plate is usually attached to the rear end of a truck and has a structure that raises and lowers the gate plate while keeping it horizontal to prevent cargo from falling off the gate plate.

[0004] In recent years, it has been proposed to provide side guards on a gate plate to prevent cargo from accidentally falling off or falling off the side edge of the gate plate during work (see, for example, Patent Document 1).

[0005] The applicant has also proposed a technology in which light-emitting elements are arranged on the side edges of a gate plate so that the side edges can be easily seen when working at night or in a dark place, thereby enabling workers to easily recognize the widthwise edges of the gate plate (see Patent Document 2).

[0006] However, when a worker performs loading and unloading work on a gate plate, the worker may lose balance. In such a case, if a safety fence that the worker can grab with his / her hand is provided, the worker can work with peace of mind. Therefore, it is considered to provide a safety fence on the edge of the gate plate in the vehicle width direction. However, since the gate plate of the tailgate mechanism is stored in an upright state at the rear of the vehicle during driving when no loading and unloading work is being performed, the safety fence on the gate plate needs to be removable or foldable relative to the gate plate. In response to such technical issues, for example, a safety fence has been provided on a liftable gate plate that guides a wheelchair or the like from the rear of the vehicle into the vehicle, and a mechanism for the safety fence that opens and closes in conjunction with the opening and closing of the gate plate has been proposed (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-030628 A [Patent Document 2] JP 2019-006246 A [Patent Document 3] Japanese Patent Application Publication No. 08-020277 Summary of the Invention [Problem to be solved by the invention]

[0008] It is conceivable to apply the technology described in the above Patent Document 3 to the tailgate mechanism of a truck to open and close the safety fence in accordance with the opening and closing of the gate plate. However, in order to link the opening and closing of the safety fence with the change between when the gate plate is stored and when it is in use, an extremely complicated mechanism is required. In addition, in order to later install a safety fence as disclosed in Patent Document 3 on a gate plate that does not have a safety fence attached, it is necessary to replace the entire tailgate mechanism and make extensive modifications to the vehicle, which requires a considerable amount of cost. In addition, since the mechanism of the safety fence is complicated, it cannot be repaired immediately in the event of a breakdown, and it is difficult to say that the structure is appropriate for a tailgate mechanism of a vehicle used for cargo transportation.

[0009] The present invention has been made in consideration of the above-mentioned facts, and its main technical object is to provide a support structure for a vehicle safety fence that is simple and robust in structure and can be easily installed on existing structures, and a fall prevention device to be installed on the support structure for the safety fence. [Means for solving the problem]

[0010] In order to solve the above-mentioned main technical problem, according to the present invention, there is provided a support structure for a safety fence which is installed on a gate plate which is disposed at an opening of a vehicle and which is raised and lowered between the ground surface and the floor surface inside the vehicle, and which is capable of changing its posture between a stored state in which it is folded up on the gate plate and an upright state, the safety fence comprising: an upright member whose posture changes between the stored state and the upright state; a rotating shaft which is disposed on one end side of the upright member and which serves as a rotation center when the posture changes; an engaging member which is disposed movably in the longitudinal direction of the upright member; a compression spring which is supported by the upright member and presses the engaging member towards the one end side; a cord-like member which pulls the engaging member towards the other end side of the upright member; and a support base which supports the upright member, the support base comprising a rotating shaft support part which rotatably supports the rotating shaft, and an engaged member which the engaging member engages with, the engaged member comprising a first engaging recess which engages with the engaging member when the safety fence is in the stored state to maintain the stored state, and a second engaging recess which engages with the engaging member when the safety fence is in the upright state. and a second engagement recess with which the engaging member engages to maintain the upright state when the safety fence is in a stored state and a connection portion connecting the first engagement recess and the second engagement recess and through which the engaging member moves when the state of the safety fence changes between the stored state and the upright state. The safety fence is provided with an engagement release mechanism including a fixed connecting portion to which one end of the rope-like member is connected, a movable wrapping portion around which the rope-like member, which is connected to the engaging member and can move in the direction in which the engaging member moves, and a fixed wrapping portion that is fixed to the safety fence and around which the rope-like member is wrapped. One end of the rope-like member is connected to the fixed connecting portion and is wrapped around the movable wrapping portion and the fixed wrapping portion in that order. When a tensile force is applied to the other end side of the rope-like member, the movable wrapping portion moves and a force is applied to the engaging member in a direction that releases the engagement of the engaging member with the first engagement recess or the second engagement recess.

[0011] The safety fence is disposed at the edge portion of the gate plate in the vehicle width direction, the standing members include a first standing member on the front side of the vehicle and a second standing member on the rear side of the vehicle, the support base includes a first support base supporting the first standing member and a second support base supporting the second standing member, the first standing member is provided with a first connecting rod having one end connected to the engaging member of the first standing member, the second standing member is provided with a second connecting rod having one end connected to the engaging member of the second standing member, the other end side of the first connecting rod and the other end side of the second connecting rod are connected by a rod connecting bar extending in the front-rear direction of the vehicle, the rod connecting bar is held so as to be movable in parallel in the longitudinal direction of the first standing member and the second standing member, and the moving wrapping Department and It is preferable that the support structure is provided on each of the first standing member and the first support base, and the second standing member and the second support base.

[0012] It is preferable that the other end side of the first upright member and the other end side of the second upright member are connected by a connecting member extending in the fore-and-aft direction of the vehicle, the fixed connecting portion and the fixed wrapping portion are arranged on the connecting member, and the tensile force acting on the other end side of the cord-like member is transmitted to the engaging member via the rod connecting bar, the first connecting rod, and the second connecting rod, and acts in a direction that releases the engagement of the engaging member with the first engaging recess or the second engaging recess in the first support base and the second support base.

[0013] The cord-like member is a flat belt, and one end of the flat belt is connected to a fixed connecting part disposed substantially at the center of the connecting member, The rod connecting bar and the fixed winding portion It is preferable that the engaging member is wound around the wire in sequence, and the engaging member is preferably a rotating roller.

[0014] In addition, in order to solve the above-mentioned main technical problem, according to the present invention, there is provided a fall prevention device that is arranged on the support structure of the above-mentioned safety fence, wherein the safety fences are a pair of safety fences arranged at opposing positions at the vehicle widthwise edge portion of the gate plate, a connectable portion is formed at the rear end portion of one of the safety fences, and a fall prevention belt is stored in the other safety fence that is retracted by an elastic member and can be retracted from a retractable portion arranged at the rear end of the other safety fence, and the connecting end of the fall prevention belt retracted from the retractable portion of the other safety fence is configured to be connectable to the connectable portion of the one of the safety fences. Effect of the Invention

[0015] The support structure for a safety fence of the present invention is a support structure for a safety fence that is installed on a gate plate that is disposed at an opening of a vehicle and that is raised and lowered between the ground surface and the floor surface inside the vehicle, and that is capable of changing its posture between a stored state folded into the gate plate and an upright state. The safety fence comprises an upright member whose posture changes between the stored state and the upright state, a rotation axis that is disposed on one end side of the upright member and serves as the center of rotation when the posture changes, an engagement member that is disposed movably in the longitudinal direction of the upright member, and a locking member that is supported by the upright member and faces the one end side. the safety fence includes a compression spring which presses the engaging member, a cord-like member which pulls the engaging member towards the other end of the standing member, and a support base which supports the standing member, the support base including a rotating shaft support part which rotatably supports the rotating shaft, and an engaged member which engages with the engaging member, the engaged member including a first engaging recess which engages with the engaging member when the safety fence is in a stored state to maintain the stored state, and a second engaging recess which engages with the engaging member when the safety fence is in a standing state to maintain the standing state, and a connecting portion that connects the first engagement recess and the second engagement recess, and through which the engagement member moves when the state of the safety fence changes between a stored state and an upright state. The safety fence is provided with a disengagement mechanism that includes a fixed connecting portion to which one end of the rope-like member is connected, a movable wrapping portion around which the rope-like member, which is connected to the engagement member and can move in the direction in which the engagement member moves, and a fixed wrapping portion that is fixed to the safety fence and around which the rope-like member is wrapped. The rope-like member has one end connected to the fixed connecting portion and is wrapped around the movable wrapping portion and the fixed wrapping portion in that order, and is configured such that when a tensile force is applied to the other end side of the rope-like member, the movable wrapping portion moves and a force is applied to the engagement member in a direction in which the engagement of the engagement member with the first engagement recess or the second engagement recess is released. This provides a support structure for a safety fence that is simple in structure and robust, and can be easily installed on an existing gate plate on which no safety fence is provided.

[0016] In addition, the fall prevention device installed in the support structure of the safety fence of the present invention has a coupling part formed at the rear end of one safety fence, and the other safety fence houses a fall prevention belt that is retracted by an elastic member and can be reeled out from a reel-out part disposed at the rear end of the other safety fence, and the coupling end of the fall prevention belt reeled out from the reel-out part of the other safety fence can be coupled to the coupling part of the one safety fence, so that while enjoying the effects of the support structure of the safety fence of the present invention described above, when the gate plate is raised or lowered with cargo piled up on it, the cargo is prevented from collapsing and falling backward from the gate plate. In addition, when the gate plate is set to be flush with the floor surface inside the vehicle, the fall prevention belt is reeled out and the coupling end is coupled to the coupling part, thereby reducing the anxiety of the worker when the worker moves the cargo between the inside of the vehicle and the gate plate. [Brief description of the drawings]

[0017] [Figure 1] (a) is an oblique view of a vehicle to which the safety fence of this embodiment is applied, in which the safety fence installed on a gate plate is in a stored state, and (b) is an oblique view of the safety fence shown in (a) in an upright state. [Diagram 2] 2 is an enlarged perspective view of a first safety fence and a first support base of FIG. 1(a). FIG. [Diagram 3] 3 is a see-through side view showing the inside of the first safety fence and the first support base shown in FIG. 2. [Figure 4] 2 is an enlarged perspective view showing a first disengagement mechanism of the first safety fence shown in FIG. 1. [Diagram 5] 1 is a partially see-through side view showing the first safety fence changing from a stored state (a) to an intermediate state (b) to an upright state (c). FIG. [Figure 6] An enlarged oblique view showing the first upright member and the first support base when the first safety fence is in an upright state. [Figure 7] 2 is a perspective view showing a state in which a fall prevention belt is unwound in a fall prevention device installed on the safety fence shown in FIG. 1. [Figure 8]8 is a perspective view showing a state in which the fall prevention belt shown in FIG. 7 is stored in a second handrail portion. [Figure 9] 9(a) is a plan view showing a portion of the first handrail section and the second handrail section shown in FIG. 8 with transparency, and FIG. 9(b) is a side view showing a portion of the second handrail section shown in FIG. 9(a) with transparency. [Figure 10] 10(a) is a plan view showing a portion of the first handrail section and the second handrail section shown in FIG. 7 with transparency, and FIG. 10(b) is a side view showing a portion of the second handrail section shown in FIG. 10(a) with transparency. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a support structure for a safety fence and a fall prevention device constructed based on the present invention will be described in detail with reference to the accompanying drawings.

[0019] FIG. 1 shows a vehicle 100 (shown by a two-dot chain line) having a box-shaped loading platform 110 to which the support structure and fall prevention device of the present embodiment of the safety fence are applied. FIG. 1(a) shows a tailgate mechanism 130 including a gate plate 2 arranged at the rear of the vehicle 100 and raised and lowered between the ground surface and the floor surface inside the vehicle. When the vehicle 100 is not carrying out loading and unloading work, the gate plate 2 is stored in an upright position along the opening and closing door 120 at the rear of the box-shaped loading platform 110, and when the loading and unloading work is carried out, as shown in FIG. 1(a), it is opened in the direction indicated by the arrow R1 and placed in a horizontal position. Note that the X direction indicated by the arrows in FIG. 1 is the front-rear direction of the vehicle, the Y direction is the width direction of the vehicle, and the Z direction is the up-down direction, and these XYZ directions are assumed to be common directions in the following drawings as well. In addition, in the illustrated embodiment, an example is shown in which the opening / closing door 120 at the rear of the box-type cargo platform 110 is composed of two double doors, but the present invention is not limited to this, and the opening / closing door may be divided into four doors, or a portion of the opening at the rear of the box-type cargo platform 110 may be opened and closed by a gate plate 2.

[0020] The gate plate 2 is generally rectangular and includes a load receiving surface 4, a front edge 6, a rear edge 8, a right edge 10, and a left edge 12. The first and second safety fences 20 and 30, which are safety fences according to the present embodiment, are disposed to face each other at the right edge 10 and the left edge 12. The first and second safety fences 20 and 30 are made of, for example, alloy steel, and are safety fences that can change their posture between a stored state in which they are folded into the gate plate 2 as shown in FIG. 1(a) and an upright state in which they are raised in the directions indicated by the arrows R2 and R3 as shown in FIG. 1(b) (see FIG. 1(b)). In FIG. 1(b) where the first and second safety fences 20 and 30 are in the upright state, the opening and closing door 120 at the rear of the box-shaped loading platform 110 is in an open state (not shown).

[0021] The first safety fence 20 is equipped with an upright member 24 whose position changes by 90 degrees with respect to the gate plate 2 between the stored state and the upright state. The upright member 24 includes a first upright member 24A on the rear side of the vehicle and a second upright member 24B on the front side of the vehicle. The second safety fence 30 is also equipped with a configuration substantially similar to that of the first safety fence 20 described above, and includes an upright member 34 whose position changes between the stored state and the upright state described above. The upright member 34 includes a first upright member 34A on the rear side of the vehicle and whose position changes by 90 degrees between the stored state and the upright state, and a second upright member 34B on the front side of the vehicle.

[0022] The first safety fence 20 is provided with a first support base 40 arranged behind the right edge 10 of the gate plate 2 and supporting one end side (the side that becomes lower when erected) of the first standing member 24A, and a second support base 50 arranged in front and supporting one end side (the side that becomes lower when erected) of the second standing member 24B. Similarly, the second safety fence 30 is provided with a first support base 60 arranged behind the left edge 12 of the gate plate 2 and supporting one end side (the side that becomes lower when erected) of the first standing member 34A of the second safety fence 30, and a second support base 70 arranged in front and supporting one end side (the side that becomes lower when erected) of the second standing member 34B.

[0023] The first safety fence 20 is provided with a first handrail section 22, which is a connecting member that connects the other end side (the upper side when erected) of the first standing member 24A and the other end side (the upper side when erected) of the second standing member 24B. The first standing member 24A and the second standing member 24B are connected by a horizontal member 26 in addition to the first handrail section 22. The first safety fence 20 further includes a fence extension section 27 that extends from the first standing member 24A toward the rear of the vehicle, and a first disengagement mechanism 28, which will be described in detail later.

[0024] Similarly to the first safety fence 20, the second safety fence 30 also includes a second handrail portion 32, which is a connecting member that connects the other end side (the side that becomes the upper side when erected) of the first standing member 34A and the other end side (the side that becomes the upper side when erected) of the second standing member 34B. The first standing member 34A and the second standing member 34B are connected by a horizontal member 36 in addition to the second handrail portion 32. Furthermore, the second safety fence 30 includes a fence extension portion 37 that extends from the second standing member 34B toward the rear side of the vehicle, and a second disengagement mechanism 38 that has a configuration similar to the first disengagement mechanism 28 described above.

[0025] Fig. 2 shows an enlarged view of the first upright member 24A of the first safety fence 20 and the first support base 40 in a state in which the first safety fence 20 is folded relative to the gate plate 2 shown in Fig. 1(a). Note that in Fig. 2, for the convenience of explaining the support structure between the first upright member 24A and the first support base 40, some components are shown transparently using dashed lines, etc.

[0026] 2, the first support base 40 includes a rectangular flat plate member 41 fixed on the load receiving surface 4 of the gate plate 2, a pair of rotating shaft support members 43, 44 erected perpendicular to the plate member 41 and facing each other, a connecting member 45 connecting the pair of rotating shaft support members 43, 44 on the right edge portion 10 side of the gate plate 2, and an engaged member 46 erected at an intermediate position between the rotating shaft support members 43, 44 and engaged with an engaging member described later. Bolts are inserted into the four corners of the plate member 41 from below the gate plate 2, and the plate member 41 is fixed on the upper surface of the plate member 41 by nuts B.

[0027] A rotation shaft 241 is disposed on one end side of the first standing member 24A, which becomes the center of rotation when the posture of the first standing member 24A changes from the stored state to the standing state. The rotation shaft 241 is supported by two extension plates 243, 244 that extend one end side of the first standing member 24A and are disposed so as to face each other in the X direction, and is rotatably supported by the rotation shaft support members 43, 44 of the first support base 40 described above.

[0028] 2, and also with reference to FIG. 3, the support structure formed by the first upright member 24A and the first support base 40 will be described in further detail.

[0029] The first standing member 24A includes a first connecting rod 245 supported to be movable in the longitudinal direction (Y direction in the figure) of the first standing member 24A. A slide shaft 246 connected to the first connecting rod 245 so as to be movable integrally therewith is disposed on one end side of the first connecting rod 245, and a rotating roller 242 is rotatably supported on one end side of the slide shaft 246 as an engagement member. The slide shaft 246 is inserted relatively movably through support plates 248a, 248b fixed at a distance in the longitudinal direction so as to connect the extension plates 243, 244 of the first standing member 24A, and is disposed to pass through a coil-shaped compression spring 247 disposed between the support plates 248a, 248b. One side of the compression spring 247 abuts against the support plate 248a, and the other side is supported by a pin 249 that is held to pass through in a direction perpendicular to the slide shaft 246. With this configuration, the rotating roller 242 of the first standing member 24A is pressed toward one end side of the first standing member 24A, i.e., toward the engaged member 46 side of the first support base 40. As described above, in this embodiment, the slide shaft 246, which is a separate member, is connected to one end side of the first connecting rod 245 via the connecting portion 245a, but the first connecting rod 245 and the slide shaft 246 may be formed integrally.

[0030] As shown in Figure 3, the engaged member 46 of the first support base 40 described above includes a first engagement recess 461 with which the rotating roller 242, which is an engagement member, engages when the first safety fence 20 is in a stored state, maintaining the first safety fence 20 in the stored state, a second engagement recess 462 with which the rotating roller 242 engages when the first safety fence 20 is in an upright state, maintaining the first safety fence 20 in an upright state, and a connection portion 463 that connects the first engagement recess 461 and the second engagement recess 462, and along which the rotating roller 242 moves when the state of the first safety fence 20 changes between the stored state and the upright state.

[0031] In the above description, the support structure constituted by the first standing member 24A and the first support base 40 has been described, but in the first safety fence 20 of this embodiment, the second standing member 24B and the second support base 50 are also provided with a support structure similar to that described above. That is, the second standing member 24B is provided with a second connecting rod (not shown) corresponding to the first connecting rod 245, one end of the second connecting rod is provided with a rotating roller (not shown) corresponding to the rotating roller 242, and the second support base 50 is also provided with an engaged member (not shown) corresponding to the engaged member 46. As can be seen from FIG. 1 and FIG. 2, the first safety fence 20 is provided with a rod connecting bar 29 extending horizontally and connecting the other end of the first connecting rod 245 and the other end of the second connecting rod of the second standing member 24B (not shown). 2, a long hole 240 into which an end of the core material 29b of the rod connecting bar 29 is inserted is also formed in the approximate center of the second standing member 24B, and the rod connecting bar 29 is supported so as to be movable in parallel to the longitudinal direction of the first standing member 24A and the second standing member 24B. With this configuration, by translating the rod connecting bar 29 along the long hole 240, it is possible to move the rotating roller 242, which is an engagement member of the first standing member 24A, and the rotating roller (not shown), which is an engagement member of the second standing member 24B, along the longitudinal direction of the first standing member 24A and the second standing member 24B.

[0032] 1 and 3, the first safety fence 20 of this embodiment is provided with a first disengagement mechanism 28 that functions as a disengagement mechanism for releasing the engagement of the rotating roller 242 with the first engagement recess 461 and the second engagement recess 462 of the engaged member 46. The configuration and function of the first disengagement mechanism 28 of this embodiment will be described in more detail with reference to Figs. 4 and 5 in addition to Figs. 1 to 3.

[0033] The first disengagement mechanism 28 of this embodiment is disposed at a substantially intermediate position between the first standing member 24A and the second standing member 24B in the first handrail section 22, as shown in FIG. 1. The first disengagement mechanism 28 is provided with a cord-like member 281 for pulling the rotating roller 242 of the first standing member 24A and the rotating roller (not shown) of the second standing member 24B to the other end side (left side in FIG. 3) of the first standing member 24A and the second standing member 24B. The cord-like member 281 includes, for example, a rope, a string, or a belt-like member, and is preferably a flexible and slippery member, and in this embodiment, a resin flat belt is used. As shown in FIG. 4, the cord-like member 281 is provided with one end 281a fixed to the fixed connecting portion 283 of the belt bracket 282 and a ring-shaped gripping portion 281b constituting the other end to be gripped and pulled by the operator.

[0034] The cord-like member 281, one end 281a of which is fixed to the fixed connecting portion 283 of the belt bracket 282, is wound around the rod connecting bar 29 and turned over, and then wound around a fixed winding portion 284 disposed adjacent to the fixed connecting portion 283 of the belt bracket 282 and turned over to the one end side. With this configuration, the rod connecting bar 29 functions as a moving winding portion that moves along the longitudinal direction of the first standing member 24A and the second standing member 24B by pulling the cord-like member 281 in the direction indicated by the arrow R4. As can be seen from Figs. 2 and 3, the rod connecting bar 29 is configured to include at least a hollow pipe-shaped outer portion 29a and a core material 29b, and as shown in Fig. 4, by pulling the cord-like member 281 in the direction indicated by the arrow R4 as described above, the outer portion 29a of the rod connecting bar 29 can be smoothly moved in the direction indicated by the arrow R5 in the figure while rotating.

[0035] Figure 5 shows how, by operating the above-mentioned first engagement release mechanism 28, the first safety fence 20 changes from a stored state (a) in which it is folded into the gate plate 2, through an intermediate state (b), to an upright state (c).

[0036] First, when the first safety fence 20 is in the stored state (a) shown in Fig. 5, the rotating roller 242 of the first standing member 24A is pressed against the first engaging recess 461 of the engaged member 46 by the action of the compression spring 247 and engaged. As a result, the first safety fence 20 is fixed in the stored state (a). Here, the operator grasps the gripping portion 281b of the cord-like member 281 of the first engagement release mechanism 28 and pulls it in the direction shown by the arrow R4 in Fig. 4. As described above, the rod connecting bar 29 is connected to the rotating roller 242 via the first connecting rod 245 of the first standing member 24A and to the rotating roller (not shown) via the second connecting rod of the second standing member 24B. Therefore, the tensile force acting on the cord-like member 281 becomes a force resisting the compression spring force of the compression spring 247 via the pin 249 of the slide shaft 246, and acts in the direction shown by the arrow R6 in Fig. 5, disengaging the rotating roller 242 from the first engagement recess 461 of the engaged member 46. At the same time, the engagement of the rotating roller (not shown) of the second standing member 24B from the first engagement recess of the engaged member (not shown) of the second support base 50 is also disengaged.

[0037] As can be seen from the intermediate state (b) in Fig. 5, the worker can raise the first safety fence 20 in the direction indicated by the arrow R7, and while grasping the first handrail portion 22, change the position of the first safety fence 20 further toward the upright state (c). At this time, the worker can release the cord-like member 281, and the rotating roller 242 of the first upright member 24A is moved while contacting the above-mentioned connection portion 463 of the engaged member 46, and the first safety fence 20 becomes the upright state (c) upright with respect to the gate plate 2 (see also Fig. 6). As a result, the rotating roller 242 is pressed toward the engaged member 46 by the action of the compression spring 247, and automatically engages with the second engagement recess 462, and becomes the upright state (c) (for convenience of explanation, the rotating shaft support members 43 and 44 are omitted in Fig. 6).

[0038] Here, as shown in the drawing, a step portion 243a is provided on the side of the extension plate 243 in this embodiment that abuts against the connecting member 45 of the first support base 40, and when the rotating roller 242 engages with the second engagement recess 462 of the engaged member 46, the step portion 243a abuts against the connecting member 45 of the first support base 40. A step portion of a similar shape is also formed on the other extension plate 244, which abuts against the connecting member 45. As a result, when the rotating roller 242 is engaged with the second engagement recess 462, the first safety fence 20 is restricted from falling inward and is also restricted from falling outward, so that the upright position (c) is well maintained.

[0039] Incidentally, the first disengagement mechanism 28 has a configuration for reducing the pulling force of the operator, the principle of which can be explained using a so-called movable pulley. That is, the fixed winding part 284 of the first disengagement mechanism 28 corresponds to a so-called fixed pulley, and the rod connecting bar 29 corresponds to a so-called movable pulley. With this configuration, the force required when the operator pulls the cord-like member 281 to disengage the rotating roller 242 from the first engagement recess 461 against the compression spring force of the compression spring 247 is reduced by half compared to the case where the configuration is not provided. As a result, the spring force of the compression spring 247 can be made stronger within the range of the pulling force that the operator can apply to the cord-like member 281, and the state when the first safety fence 20 is in the stored state (a) or the upright state (c) can be more appropriately maintained.

[0040] When the first safety fence 20 is changed from the upright state (c) to the stored state (a), the operator pulls the grip portion 281b of the cord-like member 281, and the tensile force acts on the rod connecting bar 29 which functions as the moving winding portion, disengaging the rotating roller 242 from the second engagement recess 462, and also disengaging the rotating roller (not shown) from the second engagement recess in the second upright member 24B, thereby bringing the first safety fence 20 to the intermediate state (b), and then to the stored state (a) in which it is folded up against the gate plate 2.

[0041] Furthermore, the second safety fence 30 shown in Figure 1 also has a configuration similar to that of the first safety fence 20 described above, and by pulling the cord-like member of the second engagement release mechanism 38 arranged on the second safety fence 30, the rod connecting bar 39 of the second safety fence 30 can be moved, thereby easily operating the second safety fence 30 between the stored state shown in Figure 1(a) and the upright state shown in Figure 1(b) (detailed explanation is omitted).

[0042] In the above embodiment, an example was shown in which the rotating roller 242 was provided as the engaging member, but the present invention is not limited to the engaging member being the rotating roller 242. For example, instead of the rotating roller 242, it is possible to configure the tip of the slide shaft 246 with a curved surface coated with fluororesin having excellent slip properties, or to form a curved surface coated with ultra-high molecular weight polyethylene or the like.

[0043] In addition, in the above-described embodiment, an example is shown in which the first engagement release mechanism 28 of the first safety fence 20 is arranged in the first handrail portion 22, but the present invention is not limited to this. For example, a horizontal member connecting the first upright member 24A and the second upright member 24B of the first safety fence 20 can be arranged separately from the first handrail portion 22, and the first engagement release mechanism 28 can be arranged on the horizontal member.

[0044] Furthermore, a fall prevention device, which will be described below with reference to Figures 7 to 10, is provided on the first safety fence 20 and the second safety fence 30 that constitute a pair of safety fences arranged at opposing positions on the edge portion in the vehicle width direction of the gate plate 2 of this embodiment. Note that the box-shaped loading platform 110 of the vehicle 100 on which the gate plate 2 is arranged is omitted in Figures 7 and 8.

[0045] As shown in Fig. 7 and Fig. 8, the fall prevention device of this embodiment includes a substantially D-shaped connected part 80 formed at the rear end of the first safety fence 20 on one side, a fall prevention belt 91 that can be stored in the second safety fence 30 on the other side and can be reeled out in the direction indicated by the arrow R8 from a reel-out part 90 disposed at the rear end of the second safety fence 30, and a connecting end 92 formed at the end of the fall prevention belt 91. The connecting end 92 of the fall prevention belt 91 reeled out from the reel-out part 90 of the second safety fence 30 is connected to the connected part 80 of the first safety fence 20 as shown in the figure. By setting a fall prevention device including such a fall prevention belt 91, for example, when the gate plate 2 is raised or lowered with luggage piled up on it, the luggage is prevented from collapsing and falling backward from the gate plate 2. In addition, with the gate plate 2 set at the same height as the floor surface inside the vehicle, when a worker moves luggage between the inside of the vehicle and the gate plate 2, the worker can pay out the fall prevention belt 91 and connect the connecting end 92 to the connected part 80, thereby reducing the worker's anxiety about luggage falling, etc., and further improving work safety.

[0046] 8 shows the fall prevention belt 91 stored inside the second handrail section 32 that connects the upper part of the first standing member 34A and the upper part of the second standing member 34B of the second safety fence 30. When the fall prevention belt 91 is stored in the second handrail section 32, the hook-shaped connecting end 92 stops at the reel-out section 90 and is exposed to the rear.

[0047] Fig. 9(a) shows a plan view of the first handrail portion 22 of the first safety fence 20 and the second handrail portion 32 of the second safety fence 30 (for convenience of explanation, the distance between the two is shown narrow). Fig. 9(b) shows a side view of the second handrail portion 32. Note that the second handrail portion 32 shown in Figs. 9(a) and 9(b) shows a state in which the fall prevention belt 91 is stored inside the second handrail portion 32, and for convenience of explanation, the internal configuration is shown in a see-through manner.

[0048] An elastic member 93 is disposed inside the second handrail portion 32 (the shape of the spring in the middle portion is omitted). The elastic member 93 is, for example, a tension coil spring. One end 93a of the elastic member 93 is engaged with the end of the second handrail portion 32 on the vehicle front side (left side in the figure), and the other end 93b is engaged with a locking portion 94a of a belt slider 94 held in the second handrail portion 32 so as to be slidable in the longitudinal direction. The belt slider 94 is formed with a winding portion 95 around which the fall prevention belt 91 is wound. The winding portion 95 of this embodiment includes a first winding portion 95a disposed on the vehicle rear side (right side in the figure) along the longitudinal direction of the second handrail portion 32, and a second winding portion 95b disposed on the vehicle front side. A belt fixing portion 96 to which a fixed end 91a of the fall prevention belt 91 is fixed is disposed on the side of the payout portion 90 inside the second handrail portion 32. The fall prevention belt 91 with the fixed end 91a fixed to the belt fixing portion 96 is first wound around a first winding portion 95a of the belt slider 94 and reversed, then wound around a belt reversing portion 97 disposed near the belt fixing portion 96 and reversed, and then wound around a second winding portion 95b of the belt slider 94 and reversed, and the connecting end 92 of the fall prevention belt 91 is engaged with the payout portion 90 of the second handrail portion 32. In addition, a guide pin 98 is also disposed in the second handrail portion 32 of this embodiment to separate the fall prevention belt 91 reversed at the belt reversing portion 97 from the above-mentioned belt fixing portion 96 so that it does not interfere with it. With the above-mentioned configuration, the tensile force of the elastic member 93 described above is constantly acting on the belt slider 94, and the entire fall prevention belt 91 is pulled into the inside of the second handrail portion 32.

[0049] In the fall prevention device having the above configuration, when the fall prevention belt 91 is unwound as shown in Fig. 7 and Fig. 10 to connect the connecting end 92 of the fall prevention belt 91 to the connected part 80, the worker grasps and pulls the connecting end 92 to unwound the fall prevention belt 91 from the unwound part 90 of the second handrail part 32. As a result, the belt slider 94 disposed inside the second handrail part 32 slides in the direction shown by the arrow R9 in Fig. 9 and Fig. 10, that is, toward the unwound part 90, against the tensile force of the elastic member 93. Here, the length of the fall prevention belt 91 is set to a length including only the play that is sufficient for the connecting end 92 to be unwound from the unwound part 90 of the second handrail part 32 and for the connecting end 92 to reach the connected part 80 on the first handrail part 22 side and engage with the connected part 80. As a result, even if a force acts to pull out the fall prevention belt 91 further, the fall prevention belt 91 is prevented from being stretched and bent more than necessary, and even if the luggage piled up on the gate plate 2 tries to collapse, the fall prevention belt 91 supports the luggage and prevents the luggage from collapsing.

[0050] As described above, the fall prevention device of this embodiment is equipped with a mechanism for reducing the pulling force of the worker, the principle of which can be explained using a so-called movable pulley. More specifically, the first winding portion 95a and the second winding portion 95b correspond to the movable pulley, the belt reversal portion 97 corresponds to the fixed pulley, and the belt slider 94 on which the first winding portion 95a and the second winding portion 95b are arranged is pulled by the tension coil spring 93. Therefore, the pulling force required to pull the connection end portion 92 to pay out the fall prevention belt 93 is reduced to 1 / 4 compared to the case where the above mechanism is not provided, due to the principle of the movable pulley. [Explanation of symbols]

[0051] 2: Gate plate 4: Loading surface 6: Front edge 8: Rear edge 10:Right edge 12: Left edge 20:First safety fence 22:First handrail part 24: Standing member 24A: First upright member 241: Rotation axis 242: Rotating roller 243, 244: Extension plate 245: First connecting rod 246: Slide shaft 247: Compression spring 24B: Second standing member 26: Horizontal member 27:Fence extension 28:First disengagement mechanism 281: Cord-like member 281a: One end 281b: Gripping part (other end) 282: Belt bracket 283: Fixed connection part 284: Fixed winding part 29: Rod connecting bar 29a: External shape 29b: Core material 30:Second safety fence 34: Standing member 34A: First upright member 34B: Second standing member 36: Horizontal member 37:Fence extension 38:Second disengagement mechanism 39: Rod connecting bar 40:First support base 41: Plate member 43, 44: Rotating shaft support member 45: Linked member 46: Engaged member 461: First engagement recess 462: Second engagement recess 463: Connection 50:Second support base 60:First support base 70:Second support base 80: Joined part 90: Feeding section 91: Fall prevention belt 92: Joining end 93: Elastic material 93a: One end 93b: Other end 94: Belt slider 94a: Locking part 95: Wrapping section 95a: First wrapping part 95b: Second wrapping section 96: Belt fixing part 97: Belt reversal part 98: Guide pin 100:Vehicle 110: Box-type loading platform 120: Opening and closing door 130: Tailgate mechanism

Claims

1. A support structure for a safety fence, which is installed on a gate plate disposed at an opening of a vehicle and raised and lowered between the ground surface and a floor surface inside the vehicle, and which can change its posture between a stored state folded up by the gate plate and an upright state, The safety fence comprises an upright member whose posture changes between a stored state and an upright state, a rotation axis disposed on one end side of the upright member and serving as the center of rotation when the posture changes, an engaging member disposed movably in the longitudinal direction of the upright member, a compression spring supported by the upright member and pressing the engaging member toward the one end side, a cord-like member for pulling the engaging member toward the other end side of the upright member, and a support base for supporting the upright member; the support base includes a rotating shaft support portion that rotatably supports the rotating shaft, and an engaged member with which the engaging member engages; The engaged member comprises a first engaging recess with which the engaging member engages when the safety fence is in a stored state, maintaining the stored state, a second engaging recess with which the engaging member engages when the safety fence is in an upright state, and a connecting portion that connects the first engaging recess and the second engaging recess, and through which the engaging member moves when the state of the safety fence changes between the stored state and the upright state, The safety fence is provided with an engagement release mechanism including a fixed connection portion to which one end of the rope-like member is connected, a movable winding portion around which the rope-like member, which is connected to the engagement member and can move along the direction in which the engagement member moves, is wound, and a fixed winding portion that is fixed to the safety fence and around which the rope-like member is wound, The one end of the rope-like member is connected to the fixed connecting portion, and the rope-like member is wound around the moving winding portion and the fixed winding portion in this order. A support structure for a safety fence configured so that when a tensile force acts on the other end side of the cord-like member, the moving wrapping portion moves, and a force acts on the engaging member in a direction such that the engaging member is disengaged from the first engaging recess or the second engaging recess.

2. The safety fence is disposed at an edge portion of the gate plate in a vehicle width direction, The standing members include a first standing member on the rear side of the vehicle and a second standing member on the front side of the vehicle, The support base includes a first support base supporting the first standing member and a second support base supporting the second standing member, A first connecting rod is disposed on the first standing member, one end of which is connected to the engaging member of the first standing member, and a second connecting rod is disposed on the second standing member, one end of which is connected to the engaging member of the second standing member, and the other end of the first connecting rod and the other end of the second connecting rod are connected by a rod connecting bar extending in the front-rear direction of the vehicle, The rod connecting bar is held so as to be movable parallel to the longitudinal direction of the first standing member and the second standing member, and functions as the moving winding portion; 2. The support structure for a safety fence according to claim 1, wherein the support structure is provided on each of the first standing member and the first support base, and the second standing member and the second support base.

3. The other end side of the first standing member and the other end side of the second standing member are connected by a connecting member extending in the front-rear direction of the vehicle, The fixed connecting portion and the fixed winding portion are disposed on the connecting member, A support structure for a safety fence as described in claim 2, wherein a tensile force acting on the other end side of the cord-like member is transmitted to the engaging member via the rod connecting bar, the first connecting rod, and the second connecting rod, and is configured to act in a direction such that the engaging member is disengaged from the first engaging recess or the second engaging recess in the first support base and the second support base.

4. A support structure for a safety fence as described in claim 3, wherein the cord-like member is a flat belt, one end of which is connected to a fixed connecting portion arranged approximately in the center of the connecting member, and which is wound in turn around the rod connecting bar and the fixed winding portion.

5. 5. The support structure for a safety fence according to claim 1, wherein the engaging member is a rotating roller.

6. A fall prevention device provided on a support structure for a safety fence according to any one of claims 1 to 5, The safety fence is a pair of safety fences arranged at opposing positions on the edge portions of the gate plate in the vehicle width direction, A connecting portion is formed at the rear end of one of the safety fences, The other safety fence houses a fall prevention belt that can be retracted by an elastic member and retracted from a retractable portion arranged at the rear end of the other safety fence, and the connecting end of the fall prevention belt retracted from the retractable portion of the other safety fence is configured to be connectable to the connected portion of the one safety fence.

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