Sheet shutter

Abstract

To prevent damage to a base end part of a clamping portion when wind pressure is applied to a sheet curtain, by restricting movement of an engaging element in a width direction of the sheet curtain, compared to a case where the clamping portion is in a cantilever state with a restricting surface as the base end.SOLUTION: The sheet shutter includes a sheet curtain that opens or closes an opening, engaging elements attached to both widthwise ends of the sheet curtain, and a pair of guide rails attached to the widthwise ends of the sheet curtain and extending in a vertical direction, with engaged portions formed thereon that engage with the engaging elements so that they can move up and down. The engaged portions are formed by a pair of clamping portions that clamp the engaging elements in the thickness direction, and a main body portion that spans the base ends of the pair of clamping portions and is formed with restricting surfaces that restrict movement of the engaging elements in the width direction, and the main body portion has recesses that are recessed outward in the width direction between the restricting surfaces and the pair of clamping portions.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a sheet shutter. [Background technology]

[0002] Patent document 1 describes a guide rail for engaging and retaining locking bodies arranged on both sides of a sheet-like shutter curtain in a non-slip manner, and for guiding the opening and closing of the opening by the shutter curtain, the guide rail being composed of a support rail fixed to the main body and having a deep groove-shaped concave groove portion that opens on the inner side of the opening width, and a rigid rail body that can be freely fitted into the concave groove portion via a resilient mechanism and has a locking piece at its tip that prevents the locking body from falling out, and the rail body is a split type in which at least one of the locking pieces is displaceable, and when fitted within the concave groove portion it maintains a guiding position that prevents the locking body from falling out, but when it protrudes from the concave groove portion the displaceable locking piece is displaced to assume a release position to release the locking body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-207756 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, sheet shutters have been provided with multiple resin engaging elements at both ends of the sheet curtain that engage with guide rails. Specifically, a pair of guide rails are provided that extend vertically so as to sandwich the sheet curtain from both widthwise ends. These guide rails are made of resin, and the guide rails are formed with engaged portions that engage with the engaging elements provided at both ends of the sheet curtain. The sheet curtain moves up and down with the engaging elements provided on the sheet curtain engaged with the engaged portions of the guide rails.

[0005] Here, the engaged portion of the guide rail has a C-shaped cross section and is formed by a pair of clamping portions that clamp the engaging element in the thickness direction of the sheet curtain, and a main body portion that is hung across the base ends of the pair of clamping portions and has a restricting surface that restricts movement of the engaging element in the width direction of the sheet curtain. In this configuration, the clamping portions are in a cantilevered state with the restricting surface as the base end.

[0006] On the other hand, when wind pressure is applied to the sheet curtain while it is closing the opening, the engaging elements at both ends of the sheet curtain engage with the engaged parts of the guide rail, causing the sheet curtain to swell. If this wind pressure becomes strong, the clamping parts that form the engaged parts will bend in a cantilevered state, and the base end of the clamping parts may be damaged.

[0007] The object of the present disclosure is to restrict the movement of the engaging element in the width direction of the sheet curtain when wind pressure is applied to the sheet curtain, and to prevent the base end portion of the clamping portion from being damaged compared to when the clamping portion is in a cantilevered state with the restricting surface as its base end. [Means for solving the problem]

[0008] The sheet shutter according to the first aspect of the present disclosure comprises a sheet curtain that opens or closes an opening by moving up and down, engaging elements attached to both ends of the sheet curtain in the width direction and arranged in a row in the vertical direction, and a pair of guide rails that are respectively arranged at both ends of the sheet curtain in the width direction and extend in the vertical direction, with which the engaging elements can engage so as to be movable in the vertical direction and on which concave engaging portions that are open on the inside in the width direction are formed, the engaging portions being formed by a pair of clamping portions that clamp the engaging elements from the thickness direction of the sheet curtain, and a main body portion that is hung across the base ends of the pair of clamping portions and on which regulating surfaces that regulate the movement of the engaging elements in the width direction are formed, and the main body portion is characterized in that a recess that is recessed outward in the width direction is formed in each of the portions of the main body portion between the regulating surfaces and the pair of clamping portions.

[0009] According to the above configuration, the restricting surfaces formed on the main body restrict movement of the engaging elements in the width direction. Furthermore, recesses recessed outward in the width direction are formed in the main body between the restricting surfaces and the pair of clamping portions. That is, the clamping portions are cantilevered with the bottoms of the recesses as their base ends. Therefore, the length of the cantilevered portions is longer than when the clamping portions are cantilevered with the restricting surfaces as their base ends, and therefore, more energy is absorbed by the deflection of the clamping portions than when the clamping portions are cantilevered with the restricting surfaces as their base ends.

[0010] This restricts the movement of the engaging element in the width direction of the sheet curtain when wind pressure is applied to the sheet curtain, and prevents the base end portion of the clamping portion from being damaged compared to when the clamping portion is in a cantilevered state with the restricting surface as its base end.

[0011] A sheet shutter according to a second aspect of the present disclosure is characterized in that, in the sheet shutter described in the first aspect, the regulating surface faces inward in the width direction, and the portion of the engaged portion that is outward in the width direction from the regulating surface is made into a regulating area in which the movement of the engaging element is regulated by the regulating surface, and a gradual change portion is formed at the base end portion of the clamping portion and in the regulating area in which the thickness of the clamping portion gradually increases.

[0012] According to the above configuration, a gradually changing portion in which the thickness of the clamping portion gradually increases is formed in the regulating area where the movement of the engaging element is regulated, thereby preventing damage to the base end portion of the clamping portion without hindering the movement of the engaging element moving within the engaged portion.

[0013] A sheet shutter according to a third aspect of the present disclosure is characterized in that, in the sheet shutter described in the second aspect, the engaging element arranged in the engaged portion is movable in the thickness direction, and the regulating surface is formed so as to come into contact with the center of the engaging element in the thickness direction even when the engaging element has moved in the thickness direction.

[0014] According to the above configuration, even if the engaging element engaging with the engaged portion moves in the thickness direction, the regulating surface comes into contact with the center of the engaging element, thereby preventing the engaging element from tilting toward the intended design position. [Effects of the Invention]

[0015] According to the present disclosure, when wind pressure is applied to the sheet curtain, the movement of the engaging element in the width direction of the sheet curtain is restricted, and damage to the base end portion of the clamping portion can be prevented compared to when the clamping portion is in a cantilevered state with the restricting surface as the base end. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing a sheet shutter according to an embodiment of the present disclosure. [Figure 2]FIG. 2 is a perspective view showing the upper end portion of the sheet shutter according to the embodiment of the present disclosure. [Figure 3] 1 is a perspective view showing a guide rail, a side frame, etc. provided in a sheet shutter according to an embodiment of the present disclosure. FIG. [Figure 4] 1 is an enlarged perspective view showing a curtain unit and an engagement element provided in a sheet shutter according to an embodiment of the present disclosure. FIG. [Figure 5] 1 is a perspective view showing a curtain unit and an engagement element provided in a sheet shutter according to an embodiment of the present disclosure. FIG. [Figure 6] 1A and 1B are a plan view and a side view showing an engagement element provided in a sheet shutter according to an embodiment of the present disclosure. [Figure 7] 1 is an exploded perspective view showing an end portion of a curtain unit provided in a sheet shutter according to an embodiment of the present disclosure. FIG. [Figure 8] 11 is an enlarged side view of a portion G01 in FIG. 10 showing engagement between an engagement element and an engagement recess in the sheet shutter according to the embodiment of the present disclosure. FIG. [Figure 9] FIG. 2 is an exploded perspective view showing a gear member, a contact block, a curtain unit, etc. of a sheet shutter according to an embodiment of the present disclosure. [Figure 10] 1 is a side view showing a gear member, a contact block, a curtain unit, etc. of a sheet shutter according to an embodiment of the present disclosure. [Figure 11] 1 is a cross-sectional view showing a guide unit and the like provided in a sheet shutter according to an embodiment of the present disclosure. [Figure 12] FIG. 10 is a cross-sectional view showing a guide unit provided in a sheet shutter according to a comparative example to the embodiment of the present disclosure. [Figure 13] 1A and 1B are state diagrams showing a state in which no wind pressure is applied to the sheet curtain and a state in which wind pressure is applied to the sheet curtain in a sheet shutter according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0017] An example of a sheet shutter according to an embodiment of the present disclosure will be described with reference to Figures 1 to 13. Note that arrow H shown in the figures indicates the up-down direction (vertical direction) of the sheet shutter, arrow W is perpendicular to arrow H and indicates the width direction (horizontal direction) of the sheet shutter, and arrow L is perpendicular to arrows H and W and indicates the depth direction (horizontal direction) of the sheet shutter.

[0018] (Overall composition) The sheet shutter 10 is a sheet shutter that is attached to a loading entrance 160 of a warehouse or the like, and as shown in Figures 1 and 2, it comprises a frame 12, a guide unit 14, a take-up roll 20, a curtain unit 30, a drive roll 60, and a contact block 80. The frame 12, guide unit 14, take-up roll 20, curtain unit 30, drive roll 60, and contact block 80 are symmetrical in the width direction with respect to a center line CL11 of the sheet shutter 10. The loading entrance 160 is an example of an opening.

[0019] [Frame 12] 1, the frame 12 includes a pair of side frames 22 and a shutter case 18. The pair of side frames 22 each extend in the vertical direction and are disposed on either side of the delivery entrance 160 in the width direction, at both ends of the curtain unit 30 in the width direction.

[0020] 2, the cross section of the side frame 22 is C-shaped with the inside in the width direction open. Furthermore, a guide unit 14 extending in the up-down direction is attached to each of the pair of side frames 22. Note that in this embodiment, the inside in the width direction is the side facing the center part of the sheet shutter 10 in the width direction, and the outside in the width direction is the side opposite to the side facing the center part of the sheet shutter 10 in the width direction.

[0021] The shutter case 18 extends in the width direction at the upper ends of the pair of side frames 22 and spans the pair of side frames 22. The cross section of the shutter case 18 is rectangular and extends in the depth direction.

[0022] [Winding roll 20] As shown in FIG. 2, the winding roll 20 is disposed inside the shutter case 18 on one side in the depth direction (the right side in the figure), and an end of the curtain unit 30 is attached to the winding roll 20.

[0023] The winding roll 20 extends in the width direction, and the axial direction of the winding roll 20 is the width direction. Furthermore, the winding roll 20 is rotatably supported by a frame member (not shown). The winding roll 20 is biased by a biasing member (not shown) so as to rotate in a direction in which the curtain unit 30 is wound up (hereinafter referred to as the "winding direction").

[0024] In this configuration, a force acts on the curtain unit 30 in the direction in which it is wound by the winding roll 20 .

[0025] [Curtain Unit 30] When the curtain unit 30 closes the entrance 160 of the warehouse or the like, the curtain unit 30 is disposed between a pair of side frames 22 as shown in Fig. 1. The curtain unit 30 separates the interior area of ​​the warehouse or the like from the exterior area of ​​the warehouse or the like.

[0026] 3 and 4, the curtain unit 30 includes a sheet curtain 32 and a pair of wires 36 provided at both widthwise end portions of the sheet curtain 32. The curtain unit 30 further includes a plurality of engaging elements 40 attached to both widthwise end portions of the sheet curtain 32 and arranged side by side in the vertical direction (the movement direction of the curtain unit 30), and screws 38 for attaching the engaging elements 40 to the sheet curtain 32.

[0027] -32 sheet curtains, 36 wires- The sheet curtain 32 is formed in a sheet shape from a resin material, and has a rectangular shape extending in the vertical direction (movement direction) when viewed from the depth direction, as shown in Fig. 1. In other words, the thickness direction of the sheet curtain 32 is the depth direction. The end of the sheet curtain 32 in the movement direction is attached to the winding roll 20, as shown in Fig. 2.

[0028] 4 and 5, both ends of the sheet curtain 32 in the width direction are folded back. Furthermore, the tip of the folded back portion is fused to the other overlapping portion of the sheet curtain 32. As a result, a hollow portion 32a is formed at the base end of the folded back portion of the sheet curtain 32.

[0029] The wire 36 is disposed in the hollow portion 32a and extends in the direction of movement of the sheet curtain 32, and is provided at both ends in the width direction of the sheet curtain 32. The wire 36 is formed by twisting together a plurality of wires such as steel wires. In this way, by disposing the wire 36 in the hollow portion 32a, both ends in the width direction of the sheet curtain 32 bulge in the thickness direction of the sheet curtain 32 compared to other portions.

[0030] - Engagement element 40, screw 38 - The engaging elements 40 are attached to both end portions in the width direction of the sheet curtain 32, and as shown in Figures 4 and 5, a plurality of engaging elements 40 are lined up in the moving direction of the sheet curtain 32. In other words, a plurality of engaging elements 40 are lined up in the winding direction of the sheet curtain 32. The engaging elements 40 are integrally formed using a resin material (in this embodiment, polyacetal (POM)).

[0031] As shown in Figure 6(A), when viewed from above, the engaging element 40 has a rectangular shape with a U-shaped groove portion 42 that opens on the inner side in the width direction (hereinafter referred to as the "inner side in the width direction"), and protrusions 44 are formed on each opening end of the groove portion 42.

[0032] Furthermore, the widthwise inner portion of the groove 42 is formed with a gradually changing portion 42a in which the opening width gradually widens toward the widthwise inner portion when viewed from above. Also, the widthwise outer portion of the groove 42 (hereinafter referred to as the "widthwise outer portion") is formed with an elliptical circular portion 42b in which the width widens when viewed from above. Both widthwise ends of the sheet curtain 32, which is expanded by the wire 36 (see FIG. 4), are arranged in this circular portion 42b.

[0033] Furthermore, the engaging element 40 is formed with a side surface 40a facing outward in the width direction, and a through-hole 46 having a circular cross section that penetrates from the side surface 40a to the circular portion 42b of the groove portion 42. An expanding diameter portion 46a whose diameter gradually increases outward in the width direction is formed at the outer portion of this through-hole 46 in the width direction.

[0034] Then, as shown in Figures 4 and 7, a screw 38 is inserted into this through hole 46 from the outside in the width direction, and the tip portion of the screw 38 is screwed into the wire 36, thereby attaching the engaging element 40 to both ends of the sheet curtain 32 in the width direction.

[0035] The screw 38 is a countersunk tapping screw, and when the tip portion of the screw 38 is screwed into the wire 36, the head of the screw 38 is positioned in the expanded diameter portion 46a of the through hole 46, as shown in Figures 4 and 7. This allows the head of the screw 38 to fit into the expanded diameter portion 46a of the through hole 46 and not protrude from the side surface 40a of the engaging element 40.

[0036] Furthermore, as shown in Figures 6(B) and 8, the engaging element 40 is formed with a contact portion 50 that contacts the contact block 80 and an engaging portion 54 that engages with an engaging recess 66 of a gear member 64 provided on the drive roll 60.

[0037] [Drive roll 60] 2, the drive roll 60 is disposed inside the shutter case 18 on the other side in the depth direction (the left side in the figure) and above the pair of side frames 22. Furthermore, a portion of the curtain unit 30 that can be wound by or unwound from the winding roll 20 is wound around the drive roll 60.

[0038] The drive roll 60 extends in the width direction, with the axial direction of the drive roll 60 being the width direction. The drive roll 60 is rotatably supported by a frame member (not shown). The drive roll 60 includes a roll body 62 extending in the width direction, and a pair of gear members 64 attached to both ends of the roll body 62 in the width direction.

[0039] 9, the gear member 64 is made of metal and has an annular shape, and a plurality of engaging recesses 66 that engage with the engaging portions 54 of the engaging pieces 40 are formed side by side in the circumferential direction on the outer peripheral surface of the gear member 64. In addition, a flange 78 that protrudes radially outward relative to other portions is formed on the outer side of the gear member 64 in the width direction.

[0040] 8, the engagement recess 66 has a pair of side flat surfaces 66a formed on both end portions in the gear circumferential direction, and a bottom surface 66b sandwiched between the pair of side flat surfaces 66a and facing outward in the radial direction of the gear member 64 (hereinafter referred to as the "gear radial direction"). The side flat surfaces 66a are flat, and the bottom surface 66b is curved and convex inward in the gear radial direction.

[0041] Furthermore, the driving roll 60 is rotated in both positive and negative directions by the driving force transmitted from a motor (not shown).

[0042] [Contact block 80] The contact blocks 80 are made of metal and are arranged at the other depth side and both widthwise end sides inside the shutter case 18, as shown in Fig. 2. Specifically, the contact blocks 80 are arranged on the opposite side of the gear member 64 with the engaging element 40 sandwiched therebetween, as shown in Fig. 10.

[0043] The contact block 80 is formed in an arc shape and is attached to a frame member (not shown). The contact block 80 has an inner peripheral surface 80a facing the gear member 64 side.

[0044] In this configuration, when the engaging element 40 engaged with the engaging recess 66 of the gear member 64 moves radially outward, the inner circumferential surface 80a of the contact block 80 comes into contact with the contact portion 50 of the engaging element 40. This maintains the engagement between the engaging recess 66 of the gear member 64 and the engaging element 40.

[0045] [Guide unit 14] 11, the guide unit 14 is disposed inside the side frame 22 and attached to the side frame 22. An engaging element 40 attached to the sheet curtain 32 engages with an engaged portion 100a formed on a guide rail 100 provided on the guide unit 14 so as to be movable in the up and down direction. Details of the guide unit 14 will be described later.

[0046] (Effect of overall structure) When a loading entrance 160 of a warehouse or the like is blocked by the curtain unit 30, and the drive roll 60 shown in FIG. 10 receives rotational force from the motor and rotates in the forward direction (the direction K01 shown in FIG. 10), the rotating gear member 64 sequentially engages the engaging elements 40 that approach in the tangential direction (F01 in the figure) with the engaging recesses 66. Furthermore, the rotating gear member 64 sequentially disengages the engaging elements 40 that were engaged with the engaging recesses 66, and the disengaged engaging elements 40 move away in the tangential direction (F02 in the figure). The rotating gear member 64 also causes the curtain unit 30 to be taken up by the take-up roll 20 (see FIG. 2).

[0047] Then, the portion of the curtain unit 30 that is blocking the entrance 160 moves upward while being guided by the pair of guide rails 100 shown in Figure 11. This causes the entrance 160 of the warehouse or the like to be opened by the curtain unit 30.

[0048] In contrast, when the entrance 160 of a warehouse or the like is opened by the curtain unit 30, and the drive roll 60 shown in Figure 10 receives rotational force from the motor and rotates in the negative direction (K02 direction shown in Figure 10), the rotating gear member 64 sequentially engages the engaging elements 40 approaching from the tangential direction (F11 in the figure) with the engaging recesses 66, causing the curtain unit 30 to unwind from the winding roll 20 (see Figure 2).

[0049] Furthermore, the rotating gear member 64 sequentially disengages the engaging elements 40 that were engaged with the engaging recesses 66, and the disengaged engaging elements 40 move away in the tangential direction (F12 in the figure). The rotating gear member 64 also moves the curtain unit 30 downward. As a result, the delivery entrance 160 of the warehouse or the like is blocked by the curtain unit 30.

[0050] (Main part configuration) Next, a pair of guide units 14 extending in the vertical direction will be described. As shown in Fig. 11, the guide unit 14 is disposed inside the side frame 22 and attached to the side frame 22. The guide unit 14 includes a guide rail 100, a retainer 140, and a mounting bolt 150. The guide rail 100 is disposed over the entire area in the vertical direction where the side frame 22 is provided.

[0051] [Guide Rail 100] The guide rail 100 is made of high density polyethylene (HDPE), a resin material, and extends in the vertical direction. The outer shape of the guide rail 100 is rectangular and extends in the width direction, as shown in Fig. 11, and the guide rail 100 is formed with a recessed engaged portion 100a that is open on the inside in the width direction.

[0052] The engaged portion 100a is formed by a pair of clamping portions 102 that sandwich the engaging element 40 from the depth direction and extend in the width direction, and a main body portion 104 that spans the base ends of the pair of clamping portions 102 on the outer sides in the width direction.

[0053] 11, the clamping portion 102 is cantilevered and extends in the width direction. Specifically, the base end portion of the clamping portion 102 on the outer side in the width direction is a fixed end, and the tip end portion of the clamping portion 102 on the inner side in the width direction is a free end.

[0054] In addition, a pair of flange portions 102a are formed at the tip ends of the pair of clamping portions 102 so as to protrude in opposite directions and prevent the engaging element 40 engaged with the engaged portion 100a from slipping out of the engaged portion 100a.

[0055] 11, the main body 104 is bridged over the base ends of the pair of clamping parts 102, and a restricting surface 104a facing inward in the width direction is formed on the inner part of the main body 104 in the width direction. This restricting surface 104a comes into contact in the width direction with the side surface 40a (see FIG. 6(A)) of the engaging element 40 that is movably arranged on the engaged part 100a, thereby restricting the outward movement of the engaging element 40 in the width direction.

[0056] The restricting surface 104a is spaced apart from the clamping portion 102 in the depth direction, and a recess 110 recessed outward in the width direction is formed in the portion of the main body 104 between the restricting surface 104a and the clamping portion 102. This causes the clamping portion 102 to be in a cantilevered state with the bottom of the recess 110 as its base end. The recess 110 is also formed in a restricting region B, which is on the outer side of the restricting surface 104a in the width direction, and in which the movement of the engaging member 40 is restricted by the restricting surface 104a.

[0057] The engaging element 40 engaged with the engaged portion 100a is movable in the depth direction within the engaged portion 100a, and the restricting surface 104a is formed so as to come into contact with the center portion (CE in the drawing) in the depth direction of the engaging element 40 even when the engaging element 40 has moved in the depth direction. In other words, the length of the restricting surface 104a in the depth direction is determined so that the restricting surface 104a comes into contact with the center portion CE of the engaging element 40 even when the engaging element 40 has moved in the depth direction.

[0058] On the other hand, the widthwise outer portion of the main body 104 is formed with a pair of recesses 106 into which both ends of the retainer 140, which has a C-shaped cross section, fit, and a storage recess 108 in which the head of the mounting bolt 150 is stored.

[0059] Furthermore, a rounded surface 112 is formed at the corner formed by the pair of clamping portions 102, the base end, and the bottom of the recess 110. By forming this rounded surface 112, a gradually changing portion 102b is formed at the base end portion of the clamping portion 102, where the thickness in the depth direction gradually increases toward the base end of the clamping portion 102. The gradually changing portion 102b is formed in the restriction region B.

[0060] [Retainer 140] The retainer 140 is formed by bending a sheet metal member and extends in the vertical direction. Furthermore, as shown in Fig. 11, the cross section of the retainer 140 is C-shaped with the inner side in the width direction being open, and as described above, both ends of the retainer 140 fit into the recesses 106 formed in the guide rail 100. The retainer 140 is disposed in the vertical direction over the entire range in which the guide rail 100 is provided.

[0061] [Mounting bolt 150] 11, the head of the mounting bolt 150 is disposed in a storage recess 108 formed in the guide rail 100, and the threaded portion of the mounting bolt 150 is inserted into a through-hole (not shown) formed in the retainer 140 and the side frame 22, and is tightened into a weld nut 28 attached to the side frame 22.

[0062] (Function of main components) Next, the operation of the guide unit 14 when wind pressure is applied to the sheet curtain 32 while the curtain unit 30 (sheet curtain 32) is blocking the loading entrance 160 of a warehouse or the like will be described in comparison with the guide unit 214 of the sheet shutter 210 according to the comparative embodiment. First, the guide unit 214 of the sheet shutter 210 according to the comparative embodiment will be described, focusing on the differences from the guide unit 14 of this embodiment.

[0063] [Configuration of guide unit 214] 12, the main body 304 of the guide rail 300 of the guide unit 214 does not have the recess 110 (see FIG. 11), and the restricting surface 304a formed on the main body 304 extends from the base end of one clamping portion 302 to the base end of the other clamping portion 302. In this way, the clamping portion 302 is in a cantilevered state with the restricting surface 304a as the base end.

[0064] Furthermore, the base end portion of the clamping portion 302 does not have a gradually changing portion where the thickness gradually increases in the depth direction, and the thickness of the base end portion of the clamping portion 302 is constant.

[0065] [Effect when wind pressure is applied] Next, when wind pressure is applied to the sheet curtain 32 while the curtain unit 30 is closing the loading entrance 160 of a warehouse or the like, movement of both ends of the sheet curtain 32 in the depth direction is restricted, causing the sheet curtain 32 to expand in a curved shape, as shown by the two-dot chain line in Figure 1. Here, the movement of the upper end of the sheet curtain 32 is restricted by gear members 64 (see Figure 2), and the lower end of the sheet curtain 32 is a free end, so the amount of expansion of the lower end portion of the sheet curtain 32 is greater than the amount of expansion of the upper end portion of the sheet curtain 32.

[0066] As shown in Figures 13(A) and (B), as the sheet curtain 32 expands, a force is applied to the engaging elements 40 attached to both ends of the sheet curtain 32 shown in Figure 11 to move them to the other side in the depth direction (the lower side in Figure 11), and the engaging elements 40 try to come out of the engaging portions 100a formed on the guide rail 100.

[0067] In this case, the clamping portion 302 of the guide rail 300 of the guide unit 214 and the clamping portion 102 of the guide rail 100 of the guide unit 14 will bend from their base ends as the base point, as shown in Figures 11 and 12 (see the dotted lines in each figure).

[0068] Here, the length (L01 shown in FIG. 11) of the clamping portion 102 of the guide rail 100 in which the recess 110 is formed is longer than the length (L02 shown in FIG. 12) of the clamping portion 302 of the guide rail 300 in which no recess is formed.

[0069] Therefore, the amount of bending of clamping portion 102 is greater than the amount of bending of clamping portion 302. In other words, the energy absorbed by the bending of clamping portion 102 is greater than the energy absorbed by the bending of clamping portion 302. As a result, the bending stress generated at the base end of clamping portion 102 is smaller than the bending stress generated at the base end of clamping portion 302.

[0070] (summary) As explained above, in the sheet shutter 10, the bending stress generated at the base end of the clamping portion 102 is smaller than the bending stress generated at the base end of the clamping portion 302. Also, in the sheet shutter 10, the guide rail 100 is formed with a restricting surface 104a that restricts the movement of the engaging element 40 engaged with the engaged portion 100a in the width direction. As a result, when wind pressure is applied to the sheet curtain 32, the movement of the engaging element 40 in the width direction is restricted, and damage to the base end portion of the clamping portion 102 can be suppressed more effectively than in the sheet shutter 210 according to the comparative embodiment.

[0071] Furthermore, in the sheet shutter 10, a gradually changing portion 102b whose thickness gradually increases is formed at the base end portion of the clamping portion 102. The gradually changing portion 102b is formed in a restriction area B where the movement of the engaging element 40 is restricted by the restriction surface 104a. This makes it possible to prevent the base end portion of the clamping portion 102 from being damaged without impeding the movement of the engaging element 40 that moves within the engaged portion 100a.

[0072] Furthermore, in the sheet shutter 10, the length of the restriction surface 104a in the depth direction is determined so that even if the engaging element 40 engaging with the engaged portion 100a moves in the depth direction, the restriction surface 104a comes into contact with the center portion CE of the engaging element 40 in the depth direction. As a result, even if the engaging element 40 engaging with the engaged portion 100a moves in the depth direction, the restriction surface 140a comes into contact with the center portion CE of the engaging element 40, thereby preventing the attitude of the engaging element 40 from tilting relative to the design target.

[0073] Although the present disclosure has been described in detail with respect to specific embodiments, it will be apparent to those skilled in the art that the present disclosure is not limited to such embodiments and that various other embodiments are possible within the scope of the present disclosure. For example, in the above embodiment, the gradually changing portion 102b is formed by providing the rounded surface 112 at the corner formed by the clamping portion 102, the base end, and the bottom of the recess 110. However, it is sufficient that the thickness gradually increases toward the base end of the clamping portion 102. [Explanation of symbols]

[0074] 10 Sheet shutter 32 Sheet Curtain 40 Engagement element 100 guide rail 100a Engaged part 102 Clamping part 102b Gradually changing part 104 Main body 104a Regulatory aspects 110 recess 160 Carry-in entrance (example of opening) CE central part B Regulatory area

Claims

1. A sheet curtain that opens or closes the opening by moving up and down; A plurality of engaging elements are attached to both ends of the sheet curtain in the width direction of the sheet curtain and are arranged in the vertical direction; a pair of guide rails that are respectively disposed at both ends of the sheet curtain in the width direction, extend in the vertical direction, engage with the engaging elements so as to be movable in the vertical direction, and have recessed engaged portions that are open on the inside in the width direction; The engaged portion is formed by a pair of clamping portions that clamp the engaging element in the thickness direction of the sheet curtain, and a main body portion that is hung across base ends of the pair of clamping portions and has a restricting surface that restricts movement of the engaging element in the width direction, In the main body, recesses recessed outward in the width direction are formed in portions between the restricting surfaces and the pair of clamping portions. Sheet shutter.

2. The restriction surface faces inward in the width direction, a restriction area in which movement of the engaging element is restricted by the restriction surface, the restriction area being an outer portion of the engaging portion in the width direction relative to the restriction surface; a gradually changing portion in which the thickness of the clamping portion gradually increases is formed at the base end portion of the clamping portion and in the restriction region; The sheet shutter according to claim 1.

3. The engaging element disposed on the engaged portion is movable in the thickness direction, The restricting surface is formed so as to be in contact with a central portion of the engaging element in the thickness direction even when the engaging element is moved in the thickness direction. The sheet shutter according to claim 1.

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