JP7501460B2 - Shelf stopper device - Google Patents

Description

This invention relates to a shelf stopper device.

As a conventional technology for load shelf stopper devices, for example, a device for preventing slippage of a pallet on a loading shelf disclosed in Patent Document 1 is known. The device for preventing slippage of a pallet on a loading shelf disclosed in Patent Document 1 is provided on the horizontal member of the loading shelf body and includes a substantially U-shaped mounting member that is attached to the horizontal member from the side, and a stopper member that is fixed to the side of the horizontal member opposite the side to which the mounting member is attached via a nut and the mounting member. When the stopper member is fixed, the upper end of the stopper member is located above the top surface of the horizontal member and above the bottom surface of the pallet so as to suppress slippage of the pallet. Therefore, according to the device for preventing slippage of a pallet on a loading shelf disclosed in Patent Document 1, the stopper member can prevent the pallet from falling off the loading shelf.

JP 2006-182470 A

However, in the device for preventing slippage of pallets on a loading shelf disclosed in Patent Document 1, the stopper member protrudes above the load placement surface of the shelf. For this reason, when loading or unloading a load, it is necessary to lift the load from the placement surface by an additional amount equal to the amount of protrusion of the stopper member so that the load or loading device does not interfere with the stopper member. When a stopper member is provided in this way, in a load shelf with multiple placement surfaces in the vertical direction, the gap between the stopper member and the upper load shelf becomes narrow, making it difficult for loads to be loaded or unloaded. To make it easier for loads to be loaded or unloaded, the gap between the stopper member and the upper load shelf can be widened, but in this case, there is a problem that the storage efficiency of the load shelf is reduced compared to when no stopper member is provided.

The present invention was made in consideration of the above problems, and the object of the present invention is to provide a load shelf stopper device that can prevent loads from falling off the load shelf without reducing the storage efficiency of the load shelf.

In order to solve the above problems, the present invention has a hydraulic pressure generator that is provided on the loading surface of a load shelf and generates hydraulic pressure when it receives the load of a load placed on the load shelf, a volume-varying container that is connected to the hydraulic pressure generator and changes in volume according to the hydraulic pressure of the hydraulic pressure generator, a movable stopper member that is provided on the front of the load shelf and that protrudes and retracts from the loading surface, a displacement member that is connected to the movable stopper member and displaced in the direction of protruding and retracting from the loading surface, and a biasing member that applies a biasing force to the displacement member in a direction that compresses the volume-varying container, and the displacement member is characterized in that the displacement member displaces the movable stopper member so that it protrudes from the loading surface due to the expansion of the volume of the volume-varying container caused by the hydraulic pressure of the hydraulic pressure generator generated by placing a load on the loading surface, and displaces the movable stopper member so that it descends due to the biasing force when the hydraulic pressure is released when the loaded load is removed.

In the present invention, when a load is placed on the shelf, the load applies a load to the hydraulic pressure generator, and hydraulic pressure due to the load is generated in the hydraulic pressure generator. The hydraulic pressure of the hydraulic pressure generator expands the volume of the volume variable container. The expansion of the volume of the volume variable container causes the displacement member to rise against the biasing force of the biasing member, and as the displacement member rises, the movable stopper member rises and protrudes from the placement surface. The movable stopper member can prevent the load from falling from the shelf. On the other hand, when the load is removed from the shelf, the hydraulic pressure of the hydraulic pressure generator due to the placement of the load is released, so the displacement member descends due to the biasing force of the biasing member, reducing the volume of the volume variable container. As the displacement member descends, the movable stopper member also descends. As the movable stopper member descends, there is no need to lift the load more than necessary above the placement surface. Therefore, even if the movable stopper member is provided, the storage efficiency of the shelf is not reduced.

In the above-mentioned luggage shelf stopper device, a guide member for guiding the movable stopper member in the retracting direction may be provided on the front surface of the luggage shelf.
In this case, since the guide member is provided on the front side of the shelf, the movable stopper member can be smoothly raised and lowered in the direction of projection and recess. Also, by guiding the movable stopper member, the force with which the movable stopper holds back the load that is about to come out of the shelf can be strengthened.

In the above-mentioned load shelf stopper device, the hydraulic pressure generator may be configured as a bag-shaped member made of an oil-resistant, elastically deformable rubber material and filled with hydraulic oil.
In this case, since the hydraulic pressure generator is filled with hydraulic oil, the movable stopper member can be reliably operated by placing a load on the hydraulic pressure generator. Also, since the hydraulic pressure generator is made of an oil-resistant rubber material, a hydraulic pressure generator using hydraulic oil can be realized.

Furthermore, in the above-mentioned shelf stopper device, the displacement member may have a male threaded portion extending in the protruding/retracting direction, and the movable stopper member may have a screw hole into which the male threaded portion is screwed.
In this case, the displacement member has a male threaded portion extending in the protruding/retracting direction, and the stopper member has a threaded hole into which the male threaded portion is screwed, so that the amount of protrusion of the movable stopper relative to the mounting surface can be easily adjusted by rotating the displacement member.

In addition, in the above-mentioned shelf stopper device, a stopper concealing portion is provided which conceals the movable stopper member when the movable stopper member descends from the loading surface, and the movable stopper member has an exposed portion which is exposed when it protrudes from the loading surface, and the exposed portion may be configured to have a visual identification function.
In this case, the exposed portion of the stopper member has a visual identification function, so that when the stopper member protrudes from the placement surface and the exposed portion is exposed, the movable stopper member protruding from the placement surface can be intuitively understood by the exposed portion. Therefore, the presence or absence of a load on the shelf can be confirmed by checking the exposed portion of the movable stopper. Note that the visual identification function refers to an identification function that can strongly appeal visually by a distinctive color, pattern, figure, etc.

The present invention provides a load shelf stopper device that can prevent loads from falling off a load shelf without reducing the storage efficiency of the load shelf.

1 is a perspective view of a load storage shelf to which a load shelf stopper device according to a first embodiment is applied; FIG. 2 is a front view of a main part of the shelf stopper device according to the first embodiment. FIG. 2 is a side view of a main part of the shelf stopper device according to the first embodiment. FIG. 2 is a plan view of the shelf stopper device according to the first embodiment. 1A is a front view of the load shelf stopper device when a load is placed on the load shelf, and FIG. 1B is a front view of the load shelf stopper device when a load has been removed from the load shelf. 1A is a front view showing the main parts of a luggage shelf stopper device according to a second embodiment, FIG. 1B is a plan view of the luggage shelf stopper device according to the same embodiment, and FIG. 1C is a front view of a movable stopper according to the same embodiment.

First Embodiment
Hereinafter, a load shelf stopper device according to a first embodiment will be described with reference to the drawings. In this embodiment, an example in which the load shelf stopper device is applied to a load storage shelf having multiple load shelves will be described.

As shown in FIG. 1, the cargo storage shelf 10 comprises a number of pillars 11, cross beam members 12, 13 connecting the upper ends of the pillars 11, and a cargo shelf 15 provided between the pillars 11. The pillars 11 are arranged at regular intervals in one direction (X direction) and arranged in pairs in the front and rear in a direction intersecting the one direction (Y direction). The cross beam members 12 are members that connect the upper ends of the pillars 11 in one direction (X direction). The cross beam members 13 are members that connect the upper ends of the pillars 11 in a direction intersecting the one direction (Y direction). A reinforcing member 14 is provided at the lower part of the pillars 11 to connect the pillars 11 in the direction intersecting the one direction.

Between the support posts 11, luggage shelves 15 are fixed. As shown in Figs. 2 and 3, the luggage shelves 15 are flat and have a flat loading surface 16 on which luggage W can be placed. In the luggage storage shelf 10, a plurality of luggage shelves 15 are arranged in one direction (X direction), and the luggage shelves 15 are arranged in multiple tiers in the vertical direction. In this embodiment, the luggage shelves 15 are arranged in two tiers, one above the other, and in three rows in one direction. In addition, a space that can be used as a storage space for storing luggage W is formed below the lower luggage shelf 15. Each luggage shelf 15 has an opening that allows luggage W to be put in and taken out from a direction (Y direction) that intersects with the one direction. The end face 17 on the opening side of the luggage shelf 15 corresponds to the front face of the luggage shelf 15.

Next, the cargo W will be described. As shown in FIG. 1, the cargo W is mounted on a pallet 18, and is stored on the cargo shelf 15 together with the pallet 18. The pallet 18 has an insertion port 19 that allows the forks of a forklift (not shown) to be inserted. The pallet 18 in this embodiment is a resin pallet, but it may also be a wooden pallet. For ease of explanation, the cargo W is illustrated as being box-shaped, but is not limited to being box-shaped. Furthermore, the cargo W may be composed of a single item, or may be an assembly of multiple items stacked in layers.

The load shelf 15 of this embodiment is provided with a load shelf stopper device 20. The load shelf stopper device 20 is intended to prevent the load W on the load shelf 15 from falling off the load shelf 15 together with the pallet 18. As shown in Figures 2 and 3, the load shelf stopper device 20 has a bag-shaped member 21 as a hydraulic pressure generator, a volume-varying container 22, piping 23, a movable stopper member 24, a displacement member 25, a guide member 26, and a coil spring 27 as a biasing member.

The bag-shaped member 21 is a flat bag made of an oil-resistant elastically deformable rubber material, and is filled with hydraulic oil. The bag-shaped member 21 is placed on the end surface 17 of the loading surface 16 of the shelf 15, and allows a load W to be placed on the bag-shaped member 21. A connection port 28 for connecting one end of the piping 23 is provided on the loading surface 16 side of the bag-shaped member 21. The piping 23 is a flexible pipe made of an oil-resistant material for connecting the bag-shaped member 21 and the volume-varying container 22. The other end of the piping 23 is connected to the volume-varying container 22. Note that Figures 2 and 3 show the bag-shaped member 21 without the load W placed on it.

A storage case 30 that stores the volume-varying container 22 is attached to the end surface 17 of the shelf 15. The storage case 30 is box-shaped and has a bottom plate portion 31, a top plate portion 32, a front plate portion 33, a rear plate portion 34, and a side plate portion 35. The bottom plate portion 31 supports the volume-varying container 22. The top plate portion 32 is provided with a through hole 36 through which the displacement member 25 is inserted. The front plate portion 33 and the rear plate portion 34 form a pair and connect the bottom plate portion 31 and the top plate portion 32. The rear plate portion 34 is fixed to the end surface 17 of the shelf 15 by welding. One of the pair of side plate portions 35 has an insertion hole 37 formed therein for inserting the piping 23.

The volume variable container 22 has a flexible cylindrical container body 41 and a connection port 42 provided on the bottom side of the container body 41. The container body 41 is filled with hydraulic oil. The container body 41 is a container that can expand and contract at least in the vertical direction according to the hydraulic pressure of the hydraulic oil. The other end of the piping 23 is connected to the connection port 42. When a load W is placed on the bag-shaped member 21 and the pressure of the hydraulic oil in the volume variable container 22 increases, the volume variable container 22 expands upward according to the pressure of the hydraulic oil. When the pressure of the hydraulic oil in the bag-shaped member 21 is released and a downward external force is applied, the volume variable container 22 contracts downward according to the external force. In other words, the volume variable container 22, the piping 23 and the bag-shaped member 21 form a closed circuit of the hydraulic oil.

A displacement member 25 is attached to the top of the container body 41. The displacement member 25 has a first shaft portion 43, a second shaft portion 44, a flange portion 45 provided at the lower end of the first shaft portion 43, and a male screw portion 46 provided at the upper end of the second shaft portion 44. The first shaft portion 43 is inserted into the through hole 36 of the top plate portion 32. The second shaft portion 44 extends coaxially to the upper end of the first shaft portion 43. The outer diameter of the second shaft portion 44 is smaller than the outer diameter of the first shaft portion 43. The male screw portion 46 is provided from the upper end of the second shaft portion 44. The first shaft portion 43, the second shaft portion 44, the flange portion 45, and the male screw portion 46 are integrally formed. The flange portion 45 is formed in a disk shape so that the diameter is increased from the first shaft portion 43. The lower surface of the flange portion 45 abuts against the top of the container body 41. Therefore, the displacement member 25 rises and falls in response to changes in the volume of the volume-varying container 22, that is, it can be displaced in the vertical direction.

A coil spring 27 is interposed between the top plate portion 32 and the flange portion 45 as a biasing member. The coil spring 27 is a compression coil spring, and the first shaft portion 43 of the displacement member 25 is inserted into the coil spring 27. The lower surface of the top plate portion 32 and the upper surface of the flange portion 45 function as a seat surface that supports the coil spring 27. Therefore, the coil spring 27 applies a biasing force to the displacement member 25 that always directs the displacement member 25 downward.

Next, the movable stopper member 24 will be described. The movable stopper member 24 is a rectangular plate member and is connected to the displacement member 25. The movable stopper member 24 is a member for preventing the load W from falling off the shelf 15, and protrudes from and retracts from the placement surface 16 according to the displacement of the displacement member 25. The lower end surface of the movable stopper member 24 is provided with a screw hole 47 into which the male screw portion 46 of the displacement member 25 can be screwed. By adjusting the screwing of the male screw portion 46 into the screw hole 47, the vertical position of the movable stopper member 24 relative to the displacement member 25 is adjusted. Incidentally, since the displacement member 25 is not fixed to the volume-changing container 22, the amount of protrusion of the movable stopper member 24 relative to the placement surface 16 can be adjusted simply by rotating the displacement member 25 relative to the movable stopper member 24 without removing the guide member 26 from the end surface 17.

In this embodiment, when the volume-varying container 22 is at its most contracted state, the upper end of the movable stopper member 24 is located below the mounting surface 16, and when the volume-varying container 22 is at its most expanded state, the upper end of the movable stopper member 24 protrudes above the mounting surface 16. Note that when the volume-varying container 22 is at its most contracted state, the position of the upper end of the movable stopper member 24 may be adjusted to a position that protrudes slightly above the mounting surface 16, for example, as long as the storage efficiency of the storage space in the shelf 15 is not significantly reduced.

A pair of guide members 26 are provided on the end surface 17 of the load shelf 15 to guide both ends of the movable stopper member 24. The guide member 26 has an attachment portion 51 fixed to the load shelf 15 via a bolt 48, and a guide portion 52 having a guide groove 53. The attachment portion 51 is provided with a through hole (not shown) through which the bolt is inserted. The load shelf 15 is also formed with a screw hole (not shown) into which the bolt 48 is screwed. The guide groove 53 provided in the guide portion 52 is a groove that extends in the vertical direction when the guide member 26 is attached to the load shelf 15, and is a groove with a cross section that is approximately U-shaped as shown in FIG. 4. The groove width is greater than the plate thickness of the movable stopper member 24. The guide member 26 has a function of guiding the movable stopper member 24 in the vertical direction, as well as a function of resisting the load that the movable stopper member 24 receives from the load W that is about to protrude from the load shelf 15. Note that one of the guide members 26 is not shown in FIG. 3.

Next, the operation of the load shelf stopper device 20 according to this embodiment will be described. As shown in FIG. 5(a), when a load W is placed on the load shelf 15, the bag-shaped member 21 elastically deforms so as to be crushed under the load of the load W and the pallet 18, and the hydraulic oil is discharged from the bag-shaped member 21. As the hydraulic oil is discharged from the bag-shaped member 21, the pressure of the hydraulic oil in the volume variable container 22 increases through the piping 23, and the volume variable container 22 expands upward against the biasing force of the coil spring 27. As the volume variable container 22 expands, the displacement member 25 is displaced upward, so the movable stopper member 24 rises and protrudes from the loading surface 16.

When the movable stopper member 24 protrudes from the mounting surface 16, even if the load W is displaced together with the pallet 18 from the load shelf 15 in a direction that causes it to fall toward the frontage, the pallet 18 abuts against the movable stopper member 24, restricting the displacement of the pallet 18 and the load W. Both ends of the movable stopper member 24 in the width direction (X direction) are restricted by the guide grooves 53 of the guide member 26, so it will not fall over even if it is pressed against by the load W and the pallet 18. In this way, by the movable stopper member 24 protruding from the mounting surface 16, the load W will not fall off the load shelf 15 together with the pallet 18 even if it is displaced.

Next, we will explain the case where the load W and pallet 18 are removed from the load shelf 15. When the load W and pallet 18 are scooped up by a forklift, the load W and pallet 18 are released from the bag-shaped member 21. As a result, the pressure of the hydraulic oil in the volume variable container 22 decreases, and the biasing force of the coil spring 27 overcomes the force trying to raise the displacement member 25, so the displacement member 25 descends. As the displacement member 25 descends, the volume variable container 22 shrinks, and the movable stopper member 24 descends as the displacement member 25 descends.

As shown in FIG. 5(b), when the volume of the volume variable container 22 is sufficiently reduced, the movable stopper member 24 descends to a position where it does not protrude from the mounting surface 16. The reduction in the volume of the volume variable container 22 corresponds to an increase in the hydraulic oil in the bag-shaped member 21, and the bag-shaped member 21 expands due to the increase in the hydraulic oil.

In this way, the load shelf stopper device 20 of this embodiment causes the movable stopper member to protrude from the loading surface 16 simply by placing the load W together with the pallet 18 on the load shelf 15. Also, the load shelf stopper device 20 lowers the movable stopper member 24 to a position where it does not protrude from the loading surface 16 simply by lifting the load W and the pallet 18 slightly so that the load of the load W and the pallet 18 on the bag-shaped member 21 is relieved.

The shelf stopper device 20 of this embodiment has the following advantages.
(1) When a load W is placed on the load shelf 15, a load is applied to the bag-shaped member 21 as a hydraulic pressure generator by the load W, and hydraulic pressure is generated in the bag-shaped member 21 due to the load of the load W. The hydraulic pressure of the bag-shaped member 21 expands the volume of the volume-varying container 22 through the piping 23. The expansion of the volume of the volume-varying container 22 raises the displacement member 25 against the biasing force of the coil spring 27 as a biasing member, and as the displacement member 25 rises, the movable stopper member 24 rises and protrudes from the placement surface 16. The movable stopper member 24 can prevent the load W from falling off the load shelf 15. On the other hand, when the load W is removed from the load shelf 15, the hydraulic pressure caused by the load W being placed in the bag-shaped member 21 is released, so the displacement member 25 descends due to the biasing force of the coil spring 27, reducing the volume of the volume-varying container 22. As the displacement member 25 descends, the movable stopper member 24 also descends. By lowering the movable stopper member 24, it is not necessary to lift the load W more than necessary above the placement surface. Therefore, the provision of the movable stopper member 24 does not reduce the storage efficiency of the load shelf 15.

(2) A guide member 26 that guides the movable stopper member 24 in the retracting direction is provided on the end face 17, which is the front face of the luggage shelf 15. Therefore, the movable stopper member 24 can be smoothly raised and lowered in the retracting direction guided by the guide member 26. In addition, by the guide member 26 guiding the movable stopper member 24, the force with which the movable stopper member 24 holds back the luggage W can be strengthened. Furthermore, since the guide member 26 is provided on the end face 17, it is easy to add and install the luggage shelf stopper device 20 on an existing luggage shelf.

(3) The bag-shaped member 21 serving as a hydraulic pressure generator is made of an oil-resistant, elastically deformable rubber-based material and is filled with hydraulic oil. Therefore, the movable stopper member 24 can be reliably operated by placing the load W on the bag-shaped member 21. In addition, because the bag-shaped member 21 is made of an oil-resistant rubber-based material, a hydraulic pressure generator using hydraulic oil can be realized.

(4) The displacement member 25 has a male threaded portion 46 extending in the projection/retraction direction, and the movable stopper member 24 has a screw hole 47 into which the male threaded portion 46 is screwed. Therefore, the amount of protrusion of the movable stopper member 24 from the mounting surface 16 can be easily adjusted by rotating the displacement member 25 relative to the movable stopper member 24. In particular, since the displacement member 25 is not fixed to the volume-varying container 22, the amount of protrusion of the movable stopper member 24 from the mounting surface 16 can be adjusted simply by rotating the displacement member 25 relative to the movable stopper member 24 without removing the guide member 26 from the end surface 17.

(5) Because the movable stopper member is protruded from the loading surface 16 by utilizing the load of the load W, no drive source is required to make the movable stopper appear and disappear, and the configuration of the load shelf stopper device 20 is simple.

Second Embodiment
Next, a description will be given of a load shelf stopper device according to a second embodiment. The load shelf stopper device of this embodiment differs from the previous embodiment in that the movable stopper member is exposed only when it protrudes from the loading surface. In this embodiment, the same configuration as in the first embodiment is referred to and the same reference numerals are used.

As shown in FIG. 6(a), the shelf stopper device 60 of this embodiment has a guide member 62 that guides the movable stopper member 61. As shown in FIG. 6(b), the guide member 62 has a pair of mounting portions 63 and a guide portion 64 that is generally U-shaped in plan view. The mounting portions 63 correspond to the mounting portion 51 of the first embodiment. The guide portion 64 has a pair of guide grooves 65 and a stopper concealing portion 66. The pair of guide grooves 65 are grooves that guide both ends of the movable stopper member 61 in the vertical direction. The stopper concealing portion 66 is a plate-shaped portion that conceals the movable stopper member 61 when viewed from the front when the movable stopper member 61 is lowered below the placement surface 16.

The movable stopper member 61 of this embodiment has the same shape as the first stopper member, but has an exposed portion 67 that is exposed when protruding from the mounting surface 16, as shown in FIG. 6(c). The exposed portion 67 has a visually identifiable function when viewed from the front. Specifically, the exposed portion 67 is painted yellow, which is a visually noticeable color. The portions of the movable stopper member 61 other than the exposed portion 67 are hidden by the guide member even when the movable stopper member is at its highest point. Note that the paint may be applied not only to the exposed portion 67, but also to the entire movable stopper member 61.

This embodiment provides the same effects as the effects (1) to (3) and (5) of the first embodiment. In addition, the exposed portion 67 of the movable stopper member 61 has a visual identification function. Therefore, when the movable stopper member 61 protrudes from the placement surface 16 and the exposed portion 67 is exposed, the exposed portion 67 allows the user to intuitively grasp that the movable stopper member 61 protrudes from the placement surface 16. Therefore, the presence or absence of a load W on the load shelf 15 can be confirmed by checking the exposed portion 67 of the movable stopper. Note that a visual identification function refers to an identification function that can strongly appeal visually by a distinctive color, figure, pattern, etc.

The present invention is not limited to the above embodiment, and various modifications are possible within the scope of the invention. For example, the following modifications may be made:

In the above embodiment, the bag-shaped member serving as the hydraulic pressure generator is made of a rubber-based material, but is not limited to this. The bag-shaped member may be made of any elastically deformable material capable of generating hydraulic pressure when subjected to the load of a load, and may be made of, for example, resin. Furthermore, the hydraulic pressure generator may be made of a material other than an elastically deformable bag-shaped member as long as it is capable of generating hydraulic pressure when subjected to the load of a load.
In the above embodiment, hydraulic oil is used as the liquid filled in the bag-shaped member and the volume variable container as the hydraulic pressure generator, but the liquid is not limited to hydraulic oil. The liquid filled in the bag-shaped member and the volume variable container may be a coolant used as engine cooling water. In this case, maintenance and inspection are easier than with hydraulic oil.
In the above embodiment, the volume-varying container is configured such that the container body can expand and contract. However, the volume-varying container may be configured, for example, as a cylinder and a piston that reciprocates within the cylinder, and a displacement member may be provided on the piston.
In the above embodiment, the shelf stopper device has a guide member, but this is not limited to this. If the movable stopper member can be raised and lowered smoothly, there is no need to provide a guide member. Also, the guide member is used as a member for resisting the pressing force of the load against the movable stopper member, but if a separate means for resisting the pressing force of the load against the movable stopper member is provided, the guide member does not need to be provided.
In the above embodiment, the biasing member is a compression coil spring housed in the housing case, but is not limited to this. The biasing member may be, for example, a tension coil spring that connects the lower end of the movable stopper member to the top plate of the housing case.
In the above embodiment, the load shelf is a flat plate that supports the entire bottom surface of the load (pallet), but is not limited to this. For example, the load shelf may be formed by combining a plurality of cross members, in which case a hydraulic generator may be provided on the top surface of the cross members.

10: cargo storage shelf 15: cargo shelf 16: loading surface (cargo shelf)
17 End face (shelf)
18 Pallet 20, 60 Shelf stopper device 21 Bag-shaped member (hydraulic pressure generator)
22 Volume variable container 23 Pipe 24, 61 Movable stopper member 25 Displacement member 26, 62 Guide member 27 Coil spring (biasing member)
46 Male thread portion 47 Screw hole 52, 64 Guide portion 53, 65 Guide groove 60 Shelf stopper device (second embodiment)
66 Stopper concealing portion 67 Exposed portion W Load

Claims (5)

A hydraulic pressure generator is provided on a loading surface of the load shelf and generates hydraulic pressure by receiving a load of a load placed on the load shelf;
a volume variable container connected to the hydraulic pressure generator and having a volume variable in response to the hydraulic pressure of the hydraulic pressure generator;
A movable stopper member provided on the front surface of the shelf and adapted to protrude from and retract into the storage surface;
a displacement member connected to the movable stopper member and displaced in a direction to protrude from and retract into the placement surface;
a biasing member that applies a biasing force to the displacement member in a direction that biases the volume varying container in a contracting direction,
the displacement member displaces the movable stopper member so as to protrude from the placement surface due to a volume expansion of the volume variable container caused by a hydraulic pressure of the hydraulic pressure generator generated by placing a load on the placement surface,
A load shelf stopper device characterized in that when a placed load is removed and hydraulic pressure is released, the movable stopper member is displaced downward by the biasing force. The shelf stopper device according to claim 1, characterized in that a guide member that guides the movable stopper member in the direction of emergence and retreat is provided on the front side of the shelf. The shelf stopper device according to claim 1 or 2, characterized in that the hydraulic pressure generator is a bag-shaped member made of an oil-resistant, elastically deformable rubber material and filled with hydraulic oil. The shelf stopper device according to any one of claims 1 to 3, characterized in that the displacement member has a male threaded portion extending in the projection/retraction direction, and the movable stopper member has a screw hole into which the male threaded portion is screwed. a stopper concealing portion that conceals the movable stopper member when the movable stopper member descends from the placement surface,
the movable stopper member has an exposed portion that is exposed when protruding from the placement surface,
5. The shelf stopper device according to claim 1, wherein the exposed portion has a visual identification function.

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