Door and container having the same

Abstract

To provide a door, especially a ceiling door, having high strength and rigidity and capable of being easily and safely opened / closed without causing deformation such as torsion in opening / closing, and to provide a container having the same.SOLUTION: A door 6 is openably / closably attached to a container in such a manner as to allow an opening 2a formed to be penetrated in a predetermined direction to be opened or closed, and a surface of the door forms a bulging portion whose center side bulges toward the outer side in a thickness direction relative to a peripheral edge side and is formed in such a curved surface shape as to be gently inclined to the inner side in the thickness direction toward the peripheral edge from the bulging portion in a front view.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to a door (opening / closing door) and a container provided with the same. More specifically, it relates to a door (opening / closing door) that has high strength and rigidity and can be easily and safely opened and closed without causing deformations such as twisting during opening and closing, and a container that is provided with this door, particularly on the top surface part (ceiling part).

Background Art

[0002] Conventionally, as a method for transporting powders and granules (bulk) such as wood pellets, there is a transportation method using a bulk container that utilizes a box-shaped container.

[0003] In such a bulk container, the powders and granules are loaded by being filled, for example, through an inlet provided in the upper surface wall or ceiling part that constitutes the container.

[0004] Containers are known that are provided with such an inlet and a door (hatch) for closing the inlet.

[0005] For example, in Japanese Patent Application Laid-Open No. 2001-19086 (Patent Document 1), a container with a ceiling door that can be manually opened and closed using the principle of a lever without using power has been proposed.

[0006] This container is a container for transporting large cargo. In the container, two door panels (1), (1) that open like double doors are provided on the ceiling of the container, and at appropriate positions on the side walls of the container, screw shafts (2), (2) are erected with ratchet gears (4), (4) and ratchet handles (5), (5) disposed at the lower part. Screw nuts (3), (3) that mesh with the screw shafts (2), (2) and move up and down rotatably are covered, and arms (6), (6) that bridge between the screw nuts (3), (3) and the door panels (1), (1) and open and close the door panels (1), (1) by moving up and down are disposed.

[0007] Furthermore, in Utility Model Registration No. 3129196 Gazette (Patent Document 2), a container for transporting bulk granular materials that can prevent condensation inside the outer plate of the container has been proposed.

[0008] This container for transporting bulk granular materials is a container for transporting bulk granular materials having a box shape and corner fittings at the upper and lower four corners, the container has a ceiling hatch for loading on the ceiling part, and also has an end inlet at the upper part of the rear end face of the container, the lower part of the rear end face of the container has a rear discharge port for unloading, granular materials can be loaded and transported from the ceiling hatch or the rear inlet, and the container has a heat insulation structure for the six faces constituting the same.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0010] Conventionally, the door (ceiling door) provided on the upper surface wall or ceiling part (top surface part) of the container has been formed of a plate-like body having a rectangular shape in plan view and having a high weight, as shown in FIGS. 10 and 11. Therefore, there has been a problem that opening and closing are not easy, deformation (twisting phenomenon) is likely to occur during opening and closing, and the sealing performance is insufficient.

[0011] The container with a ceiling door described in the above Patent Document 1 is easy to open and close. However, depending on the weight of the ceiling door, deformation may occur during opening and closing, and there is a risk of damage to the arm. Furthermore, further improvement is required in the airtightness of the ceiling door.

[0012] In the container for transporting bulk powders described in the above Patent Document 2, depending on the weight of the ceiling hatch, deformation may occur during opening and closing of the ceiling hatch. Furthermore, regarding the opening and closing of the ceiling hatch 30, since it is necessary for an operator to climb onto the container to perform it, further improvement is required in easily and safely opening and closing the hatch.

[0013] In view of this situation, the present invention aims to provide a door (opening and closing door), particularly a ceiling door and a container equipped with the same, which have high strength and rigidity and can be easily and safely opened and closed without causing deformation such as torsion during opening and closing.

Means for Solving the Problems

[0014] The invention described in claim 1 of the present invention is a door that is detachably mounted so as to open or close an opening formed to penetrate in a predetermined direction, wherein the opening is formed in the top surface (ceiling part) of the container, the surface of the door forms a bulging portion in which the center side bulges outward in the thickness direction with respect to the peripheral side in a front view, and is formed in a curved surface shape that gently inclines inward in the thickness direction from the bulging portion toward the periphery , one end side thereof is pivotally supported on a support shaft disposed near the opening or in the vicinity of the opening so as to be rotatable in the vertical direction, and is provided with at least one rotation assisting member for assisting the rotation in the vertical direction, and the other end side is configured to be a free end, The rotation assisting member is composed of a rotation assisting member body including a mounting portion formed in the center so as to be U-shaped, and a pair of coil portions composed of compression coil springs having a required length formed at both ends of the mounting portion, and mounting portions are formed at respective both end edges of the rotation assisting member. , The pair of coil portions are respectively mounted on both ends of the outer peripheral portion of the support shaft. At least one of the mounting portions is attached to the door. wherein the bulging length of the bulging portion is set to 10 to 20 mm and is a door characterized thereby.

[0015] The invention according to claim 2 of this invention is In the door according to claim 1, The bulging length of the bulging portion is Set to 10 to 12 mm It is characterized by that.

[0016] The invention according to claim 3 of this invention is In the door according to claim 1, The door Is provided with a peripheral wall portion that hangs or stands up from its peripheral edge It is characterized by that.

[0017] The claim of this invention 4 The invention described in Claim 1 In the door described in The shape of the door In a front view, it is selected from a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape, and all of these corners are rounded It is characterized by that.

[0018] The claim of this invention 5 The invention described in Claim 1 In the door described in The door A locking projection is provided at the central portion in the length direction of the side surface on the free end side, and engages with the locking means to lock the closing of the door. At the edge of the end portion on the free end side, a long bar-shaped reinforcing member is provided along the side surface on the free end side It is characterized by that. It is characterized by that.

[0019] The claim of this invention 6 The invention described in Comprising the door according to any one of claims 1 to 3 A container characterized by that.

Effect of the Invention

[0020] The door (opening / closing door) according to the present invention is detachably mounted so as to open or close an opening formed to penetrate in a predetermined direction, and its surface forms a bulging portion in which the center side bulges outward in the thickness direction with respect to the peripheral side in a front view, and is formed in a curved surface shape that gently inclines inward in the thickness direction from the bulging portion toward the periphery. Therefore, since this door has high strength and rigidity, it is possible to reduce its weight. As a result, it becomes possible to easily and safely open and close the door. Furthermore, since the door has high strength and rigidity, it is possible to suppress the occurrence of deformation such as torsion when it is opened and closed.

[0021] In the door, the bulging length of the bulging portion can be set to 6 to 20 mm, more preferably 10 to 12 mm. With such a configuration, the door is extremely excellent in terms of its strength and rigidity. In the present invention, the bulging length of the bulging portion is set to 10 to 20 mm.

[0022] In addition, the door can be provided with a peripheral wall portion provided so as to hang down or stand up from its peripheral edge portion. With such a configuration, it becomes possible to further improve the strength and rigidity of the door.

[0023] Furthermore, one end side of the door can be rotatably supported near the opening or in the vicinity of the opening, and the other end side can be configured to be a free end. In this case, the shape of the door can be selected from a substantially circular shape, a substantially elliptical shape, or a substantially polygonal shape in a front view, with all of these corner portions rounded. With such a configuration, it becomes possible to further reduce the occurrence of deformation (torsion phenomenon) when the door is opened and closed.

[0024] Regarding the door, it can be configured to be pivotally supported in the vertical direction on a support shaft arranged at or near the opening, and to be provided with at least one rotation support member for assisting the rotation in the vertical direction. At this time, the rotation support member is constituted by a rotation support member main body including a mounting portion formed in the central portion so as to be U-shaped, and a pair of coil portions formed of compression coil springs having a required length formed at both end portions of the mounting portion. Mounting portions are formed at both end edges of the rotation support member, the pair of coil portions are respectively attached to both ends of the outer peripheral portion of the support shaft, and at least one of the mounting portions can be attached to the door. With such a configuration, the door can be rotated with a lighter force, so that the opening and closing of the door becomes easier. In addition, in this invention, the door is configured to include at least one rotation assisting member.

[0025] The door is provided with a locking projection projecting from the central portion in the length direction of the side surface on the free end side and engaging with the locking means to lock the closing of the door, and a long bar-shaped reinforcing member arranged along the side surface on the free end side at the edge of the end portion on the free end side. With such a configuration, the strength and rigidity of the door are significantly improved, and in particular, the occurrence of deformations such as twisting when lifting the door to open the opening can be more suppressed.

[0026] Furthermore, the door is preferably mounted on an opening formed in the container, particularly an opening formed in the top surface (ceiling portion) thereof, that is, used as a ceiling door. With such a configuration, since the door is arranged such that the bulging portion faces outward (upward), even when an operator performs work on the door, the work can be performed safely. In the present invention, the opening is formed in the top surface (ceiling portion) of the container.

[0027] According to the container provided with the door or door device of the present invention, the door (opening / closing door) can be opened and closed easily and safely, so that the opening can be opened and closed easily and safely.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Mode for Carrying Out the Invention

[0029] Hereinafter, an example of the implementation of the door (hatch) or door device according to the present invention will be specifically described based on the accompanying drawings. Note that the present invention is not limited to the disclosed embodiments, and various improvements can be made without changing the gist thereof.

[0030] FIG. 1 is a schematic explanatory diagram showing an example of a container 1 including a door (hatch) or door device 6 (hereinafter referred to as "door 6") according to the present invention. FIG. 2 is a front view showing the door 6 provided on the top surface portion of the container shown in FIG. 1. FIG. 3 is a sectional view taken along the line A-A' of FIG. 2, and FIG. 4 is a sectional view taken along the line B-B'.

[0031] The container 1 is formed in an elongated box shape by a top surface portion 2, a pair of side surface portions 3, 3 on the longitudinal side, a side surface portion 4 on the front wife side, a side surface portion 5 on the rear wife side, and a bottom surface portion (not shown). In this embodiment, the container 1 is configured such that its length in the longitudinal direction is about 6.1 meters, its length in the short hand direction is about 2.5 meters, and its height is about 2.9 meters.

[0032] As shown in FIG. 1, at least one opening 2a having a required size (opening dimension) that enables the loading of the object to be conveyed is provided in the top surface portion 2 to fill the object to be conveyed into the container 1. In FIG. 1, the openings 2a are formed to penetrate one by one on the front end side and the rear end side of the top surface portion 2 so as to extend along the longitudinal direction of the container 1.

[0033] Regarding the size (opening dimension) of the opening 2a, it may be appropriately selected according to the size of the container or the like, and there is no particular limitation. In this embodiment, each of the openings 2a is configured such that the length in the longitudinal direction is about 1.7 meters and the length in the short direction is about 1.1 meters.

[0034] A door 6 that enables the opening 2a to be opened and closed is provided in the opening 2a. As shown in FIGS. 1 and 2, the door 6 is composed of a flat door body 61 having a required thickness, and the door body 61 has a size corresponding to the opening 2a in which it is disposed. In this embodiment, the door body 61 is configured such that its thickness is about 2 mm. Also, reference numeral 61e is a handle used when an operator lifts the door 6.

[0035] In this embodiment, the door body 61 is made of a metal material from the viewpoints of maintaining strength during use and mass, etc., but an appropriate material can be selected as long as the effects of this invention are not impaired. For example, general steel plates such as SS400, high weathering steel plates such as JIS SPA-H, etc. can be selected. In this embodiment, the door body 61 is made of a high weathering steel plate JIS SPA-H and has a mass of about 47 kg.

[0036] In this invention, the surface of the door body 61 constituting the door 6 forms a bulging portion 61a that bulges outward in the thickness direction (upward in this embodiment) on the center О side (central portion) with respect to the peripheral edge (peripheral portion) 61b side when viewed from the front, and is formed in a curved surface shape that gently slopes inward in the thickness direction (downward in this embodiment) from the bulging portion 61a toward the peripheral edge portion 61b. In FIGS. 3 and 4, the door body 61 has a bulging shape in which the central portions in the front-rear and left-right directions bulge upward (in the thickness direction) in a cross-sectional view. That is, this central portion forms a bulging portion 61a, and the bulging shape is formed by a gently downwardly inclined curved surface from the central portion (bulging portion 61a) toward the periphery (in the direction intersecting the thickness direction). With such a configuration, the strength and rigidity of the door 6 are improved, so that the weight of the door 6 can be reduced. Therefore, the opening and closing operation of the door 6 is extremely easy and safe.

[0037] Regarding the bulging length (bulging height) L of the central portion (bulging portion), it is preferably set to about 6 to 20 mm, more preferably about 9 to 15 mm, and even more preferably about 10 mm to 12 mm. When the bulging length L of the bulging portion is less than 6 mm, sufficient strength and rigidity tend not to be obtained. On the other hand, when the bulging length L of the bulging portion exceeds 20 mm, stress tends to be generated in the central portion when a vertical load is applied from the upper surface of the door 6, and the internal volume of the container 1 tends to become smaller due to the regulation regarding the maximum height of the container 1 in which the door 6 is provided. In particular, when the door 6 is mounted on the top surface, there is a tendency for a risk of slipping when an operator stands on this door 6. In FIGS. 1 to 4, the bulging length L of the central portion of the door body 61 is set to about 10 mm.

[0038] Regarding the door body 61, as shown in FIGS. 3 and 4, it can be configured to include a peripheral wall portion 61d provided to hang down or stand up from the peripheral edge portion 61b thereof. With such a configuration, it is possible to further improve the strength and rigidity of the door 6. Regarding the width M of the peripheral wall portion 61d, there is no particular limitation, and for example, it can be 40 mm or less.

[0039] There is no particular limitation on the opening and closing direction of the door 6. For example, with respect to the door 6, in order to open or close the outlet side (outer side) of the opening 2a, it can be configured to rotate in the vertical direction toward the outside by being rotatably supported on the upper end of the outlet side of the opening 2a or on the top surface portion 2 in the vicinity thereof. In FIGS. 1 and 2, one end (base end portion: the left side in FIGS. 1 and 2) in the short side direction of the door 6 is rotatably supported by support shafts 9, 9 arranged at a predetermined interval along the longitudinal direction of the opening 2a on the top surface portion 2 in the vicinity of the opening 2a. On the other hand, the other end side (tip portion: the right side in FIGS. 1 and 2) of the door 6 is configured to be a free end portion (61c). Therefore, the door 6 rotates in the vertical direction with the support shafts 9, 9 as fulcrums. In this embodiment, with respect to the door 6, while one end side in the short side direction is rotatably supported on the top surface portion 2 in the vicinity of the opening 2a so as to open and close in the vertical direction, the other end side is configured to be a free end portion 61c. However, it may be configured such that one end side in the longitudinal direction is rotatably supported on the upper end of the outlet side of the opening 2a or on the top surface portion 2 in the vicinity of the opening 2a, and the other end side is a free end portion.

[0040] The door 6 can be provided with a rotation assist member to assist its rotation in the vertical direction. With such a configuration, the force required to lift the door 6 can be reduced.

[0041] In FIGS. 1 and 2, as shown in FIG. 5, the rotation assist member 7 is constituted by a compression coil spring formed by winding a wire rod having a required length. It is constituted by a rotation assist member main body 71 including a coil portion 71a and attachment portions 71b, 71c formed at both ends thereof. For the rotation assist member 7, its coil portion 71a is mounted on the outer peripheral portion of the support shaft 9. The base end portion (the first attachment portion 71b) is attached to the top surface portion 2 in the vicinity of the support shaft 9 via a bracket (not shown), while the tip portion (the second attachment portion 71c) is attached to a bracket (not shown) attached to the door main body 61 constituting the door 6.

[0042] The rotation support member 7 always biases the door 6 upward. When the door 6 rotates upward, the coil portion 71a of the rotation support member 7 extends due to its biasing force. Therefore, with respect to the door 6, it can be rotated with a light force while receiving the support of the rotation support member 7.

[0043] FIG. 10 is a schematic explanatory view showing an example of a container provided with a conventional door (hatch) or door device 106 (hereinafter referred to as "door 106"), and FIG. 11 is a front view showing the door 106 provided on the top surface portion 102 of the container 101 shown in FIG. 10. In the opening 102a formed through the top surface portion 102, a door 106 that enables its opening and closing is provided. Conventionally, since the door (106) provided in the container has a high mass, there are problems such as the need to make the rotation support member (107) provided on the support shaft (108) large in order to support its rotation, and there is a risk that this rotation support member (107) may be damaged. However, in this invention, since the door body 61 constituting the door 6 is made lighter in weight, miniaturization of the rotation support member is realized.

[0044] FIGS. 6 and 7 are schematic explanatory views showing other embodiments of the rotation support member. In FIG. 6, as shown in FIG. 7, the rotation support member 8 is formed from a wire having a required length, and includes a mounting portion (first mounting portion) 81a formed in a substantially U-shape in plan view at the central portion, and a pair of coil portions 81b, 81c having a required length formed at both ends thereof. The pair of coil portions 81b, 81c are both configured as compression coil springs. Further, mounting portions (second and third mounting portions) 81d, 81e are formed at both end edges of the rotation support member 8. The rotation support member 8 has its coil portions 81b and 81c respectively attached to both ends of the outer peripheral portion of the support shaft 9, and the attachment portion 81a is attached to a bracket 15 formed on the top surface portion 2 in the vicinity of the support shaft 9 (between the periphery of the opening portion 2a and the support shaft 9). Attachment portions 81d and 81e formed at both end edges of the rotation support member 8 are attached to brackets 16 and 16 attached to the door main body 61. Regarding the attachment portions 81a, 81d, and 81e, at least one of them may be attached on the door main body 61, and at least one of the remaining attachment portions may be attached on the top surface portion 2 in the vicinity of the support shaft 9.

[0045] In the rotation support member 8 having such a configuration, since the coil portions 81b and 81c respectively constitute compression coil springs, the rotation support member 8 always biases the door 6 upward. When the door 6 rotates upward, the coil portions 81b and 81c of the rotation support member 8 extend due to their biasing force. Therefore, for the door 6, with the support of the rotation support member 8, it can rotate with a lighter force.

[0046] In FIG. 6, the rotation support member 8 is provided for each of the three support shafts 9 around which the door 6 is pivotally supported near the central portion in the longitudinal direction of the door 6 and near the left and right end portions. In FIG. 6, the rotation support member 8 is configured to be able to support (assist) about 60% of the mass or force with one. On the other hand, in FIG. 6, the door 6 has a mass of about 47 kg. When opening this door 6 using only the handle 61e on one side (holding one end of the free end portion 61c of the door 6), that is, when lifting it upward, the mass that the operator should bear is about 23.5 kg because the door 6 is supported at two points on the left and right. Therefore, when lifting the door 6 using the handle 61e on one side, about 14.1 kg of mass is supported by the rotation support member 8, that is, the rotation support member 8 can receive the support of a force of about 138 N. Therefore, when lifting the door 6 upward using the handle 61e on one side, the mass that the operator has to bear is reduced to approximately 9.4 kg (the required force is approximately 92 N), and moreover, the possibility of damage to the rotation assisting member is decreased.

[0047] The rotation assisting member (7 or 8) that exhibits such an effect can be disposed on at least one of the left and right support shafts 9, 9 on which the door 6 is pivotally supported. Depending on the mass of the door 6, it is preferable that the rotation assisting members are disposed on each of the left and right support shafts 9, 9.

[0048] Regarding the shape of the door body 61 that constitutes the door 6, there is no particular limitation as long as it can be opened and closed (rotated) in a predetermined direction. The shape of the door body 61 is preferably a shape without corners such as a substantially circular or substantially elliptical shape in a front view, or a shape having a plurality of corners such as a substantially polygonal shape (more preferably a substantially square or substantially rectangular shape, etc.), and is selected from those in which all of these corners are rounded. With such a configuration, it becomes even more difficult for the door 6 to be deformed (twisting phenomenon) when it is opened and closed. In FIGS. 1 and 2, the shape of the door body 61 is substantially rectangular in a front view (when viewed from above), and all four corners thereof are rounded.

[0049] A packing or the like can be disposed on the periphery of the door 6 or the periphery of the opening 2a to improve the sealing performance when they are in contact with each other. In this embodiment, a flange (not shown) standing upward is provided on the periphery of the opening 2a, and a packing (not shown) is disposed inside a groove having a required depth formed on the lower surface periphery of the door body 61 so as to correspond to this flange.

[0050] A locking means for locking (fixing) the closing of the door 6 can be provided on the top surface portion 2 so that the door 6 is not inadvertently opened.

[0051] In FIGS. 1 and 2, a locking means 10 is disposed near the free end 61c of the door 6 on the top surface portion 2 so as to be engageable with a locking projection 61e disposed at the end on the free end 61c side. As shown in FIGS. 8 and 9, this locking means 10 is composed of a locking means main body 10a, a hollow case member 10b, a shaft member 10c, an engaging portion 10d, a lever portion 10e, and a compression coil spring 10f.

[0052] The tip of the locking means main body 10a is supported so as to be rotatable in the same direction as the rotation direction of the door 6, that is, in the vertical direction, about the support shaft 11 of the top surface portion 2, and the case member 10b is rotatably supported at the rear end portion. The case member 10b is hollow, and its rear end portion (the end portion on the side away from the door 6) is rotatably attached to the rear end portion of the locking means main body 10a about a support shaft 17. The shaft member 10c has a required diameter and length, and is disposed in the case member 10b so as to be slidable and non-removable in a direction of approaching and separating from the door 6 (the left-right direction in FIG. 1). The tip of the shaft member 10c is disposed so as to protrude from the tip of the case member 10b. An engaging portion 10d is formed at the tip of the shaft member 10c, and a disk-shaped holding portion 10g configured to be able to hold the compression coil spring 10f is provided at the rear end portion. The engaging portion 10d is provided at the tip of the shaft member 10c, has a substantially elliptical shape in plan view, and is configured to be engageable with a locking projection 141 protruding from the surface (outer surface) of a plate-like member 14 disposed at the free end 61c of the door body 61. The lever portion 10e is for operating the locking and unlocking of the door 6, and is provided so as to extend rearward (the side away from the door 6) from the rear end portion of the locking means main body 10a. The compression coil spring 10f is formed by winding a wire rod having a required length, and is interposed between the inner surface on the tip side (door 6 side) of the case member 10b and the holding portion 10g. Since this compression coil spring 10f always biases the engaging portion 10d in a direction away from the door 6, the door 6 is not likely to be inadvertently opened when its closing is locked. In addition, in FIGS. 1 and 2, the plate-like member 14 extends laterally (rightward in FIGS. 1 and 2) along a direction parallel to the surface of the door 6 from the central portion in the longitudinal direction of the end portion on the free end portion 61c side (the central portion in the length direction (front-rear direction in FIGS. 1 and 2) of the side surface of the free end portion 61c side of the door 6), and the locking projection 141 is provided so as to project upward from the surface (outer surface) of the plate-like member 14.

[0053] In the locking means 10 having such a configuration, by lifting the lever portion 10e upward, that is, moving (rotating) it in a direction away from the top surface portion 2, the case member 10b moves in a direction toward the door 6. Along with the movement of the case member 10b, the shaft member 10c and the engaging portion 10d provided thereon also move, and the engaging portion 10d reaches a position where it can engage with the locking projection 141. In that state, by hooking the engaging portion 10d on the locking projection 141 and pushing down the lever portion 10e, that is, moving (rotating) it in a direction approaching the top surface portion 2, the door 6 is firmly fixed (locked) to the top surface portion 2. Thus, the closing of the door 6 can be locked easily and firmly. In addition, when the lever portion 10e is lifted upward again, the engagement between the engaging portion 10d and the locking projection 141 is released, and the engaging portion 10d returns to a position where it can engage with the locking projection 141, so the locking of the closing of the door 6 is released.

[0054] A reinforcing member can be disposed on the door body 61 to improve its strength and suppress the occurrence of deformations such as twisting. As the reinforcing member, for example, one made of a long rod-shaped body extending linearly can be selected.

[0055] In FIGS. 1 and 2, on the door body 61, six (three pairs) of reinforcing members (first reinforcing members) 12 are arranged so as to extend along the short side direction of the door body 61. Each of the reinforcing members (first reinforcing members) 12 is formed of a long rod-shaped body extending linearly, and is arranged so as to extend from the edge of the rotatable end of the door body 61 to the edge of the free end 61c facing it (along the short side direction (left-right direction in FIG. 1)). In FIGS. 1 and 2, among the reinforcing members (first reinforcing members) 12, the two (one pair) arranged on each of the left and right end portions are arranged so as to extend from the edge near the support shaft 9 to the edge of the free end 61c facing it. Therefore, the strength and rigidity of the door 6 are further enhanced.

[0056] In FIGS. 1 and 2, on the door body 61, further, reinforcing members (second reinforcing members) 13 are arranged so as to extend along the longitudinal direction of the door body 61 across both longitudinal edges. The reinforcing member 13 is formed of a long rod-shaped body extending linearly, and is arranged so as to extend along the edge of the end portion on the free end 61c side of the door body 61 (along the longitudinal direction or the axial direction of the rotation axis (front-rear direction in FIG. 1)).

[0057] When the door 6 is configured to be rotatable in the vertical direction, it is preferable to arrange the reinforcing member 13 near the edge of the end portion on the free end 61c side of the door body 61 so as to extend along this edge. With such a configuration, the strength and rigidity of the door body 6 are remarkably improved, and in particular, the occurrence of deformations such as twisting when lifting the door 6 to open the opening 2a can be further suppressed. Furthermore, when locking means (reference numeral 10 in FIGS. 1 and 2) configured to be engageable with the central portion of the free end 61c of the door 6 is provided, an effect that the tightening pressure by the locking means 10 is dispersed can also be obtained.

[0058] In the present invention, the door described above is configured to open and close in the vertical direction. However, there is no limitation on the specific structure of the door 6 as long as it enables the opening and closing of the opening, such as a structure in which the door slides in the front-rear or left-right direction.

[0059] Also, in the present invention, the door is disposed in the opening formed in the top surface portion of the container, but it can also be provided on the side surface portion or the bottom surface portion other than the top surface portion.

Embodiment

[0060] Hereinafter, the present invention will be described in detail with reference to embodiments, but the present invention is not limited by these embodiments.

[0061] <Embodiment 1> (Manufacture of Door) A steel plate having a vertical length of about 1100 mm, a horizontal width of about 1700 mm, and a thickness of about 2 mm was formed in a curved shape in a sectional view in which the central portion in the front-rear and left-right directions bulged upward with a bulging length of 6 mm and gently sloped downward from the central portion toward the periphery to manufacture the door.

[0062] <Embodiments 2 - 5> (Manufacture of Door) The door was manufactured in the same manner as in Embodiment 1 except that the bulging length was set to the value described in Table 1 below.

[0063] <Comparative Example> (Manufacture of Door) The door was manufactured in the same manner as in Embodiment 1 except that bulging was not performed.

[0064]

Table 1

[0065] <Test Example> Evaluation of Strength Regarding the above-mentioned door, based on the following test method, the deflection amount and stress at the central part were measured and analyzed to evaluate the strength. These results are shown in Table 2 and Figures 12 to 17.

[0066] (Test method) For the central part of the obtained door, a vertical load of 60 kg (force 588 N) was applied in a range of 600 mm in diameter using a material testing machine, and the deflection amount and stress generated at that time were measured, and analysis was performed by finite element analysis (FEA).

[0067]

Table 2

[0068] (Results) From Table 2 and Figure 12, it was found that for the door manufactured in Example 1, although it deflects slightly downward, the generation of deflection is reduced. Furthermore, in this door, the stress is reduced, and this stress is dispersed and generated within the region including the range where the load is applied and its peripheral part at the central part. Therefore, it can be seen that in this door, the strength and rigidity are improved, so weight reduction can be achieved, and the occurrence of deformations such as twisting can be suppressed. Also, from Table 2 and Figures 13 - 16, it was found that for the doors manufactured in Examples 2 - 5, there is almost no generation of deflection, and the stress is further reduced compared to the door manufactured in Example 1. Furthermore, in these doors, in each case, the stress is dispersed and generated at the peripheral part or the peripheral part and the central part within the region including the range where the load is applied or the range where the load is applied and its peripheral part. In particular, for the doors manufactured in Examples 3 and 4, in each case, the stress is dispersed and generated only at the peripheral part within the region including the range where the load is applied and its peripheral part. Therefore, it can be seen that in these doors (doors manufactured in Examples 2 - 5), the strength and rigidity are further improved, so further weight reduction can be achieved, and the occurrence of deformations such as twisting can be further suppressed. In contrast, from Table 2 and FIG. 17, it can be seen that in the door manufactured in the comparative example, it bent significantly downward, and very large stress concentrated and occurred throughout the region including the loaded area and its peripheral part. Therefore, it can be understood that this door has low strength and rigidity and is likely to undergo deformations such as twisting. From the above, it is obvious that according to the door of the present invention, since its strength and rigidity are improved, weight reduction can be achieved, and the occurrence of deformations such as twisting can be suppressed.

Industrial Applicability

[0069] The door of the present invention can be disposed in a container, particularly in an opening (loading opening for the object to be conveyed) formed in the top surface (ceiling portion) thereof, and enables the opening and closing of this opening to be performed easily and safely. Therefore, it can be used in any container.

Explanation of Reference Numerals

[0070] 1 Container 2 Top surface (ceiling portion) 2a Opening 3 Side wall (left or right side) 4 Front wife side side wall 5 Rear wife side side wall 6 Door (hatch) 61 Door body 61a Bulging portion 61b Peripheral edge portion 61c Free end 61d Peripheral wall portion 61e Handle 7 Rotation support member (first embodiment) 71 Rotation support member body 71a Coil portion (compressed coil spring) 71b Mounting portion (first mounting portion) 71c Mounting portion (second mounting portion) 8 Rotation support member (second embodiment) 81 Rotation support member body 81a Mounting part (first mounting part) 81b, 81c Coil part (compression coil spring) 81d Mounting part (second mounting part) 81e Mounting part (third mounting part) 9 Support shaft 10 Locking means 10a Locking means main body 10b Case member 10c Shaft material 10d Engaging part 10e Lever part 10f Compression coil spring 10g Holding part 11 Support shaft 12 First reinforcing member (short - side reinforcing member) 13 Second reinforcing member (long - side reinforcing member) 14 Plate - shaped member 141 Locking projection 15, 16 Bracket 17 Support shaft 101 Container 102 Top surface part (ceiling part) 102a Opening 106 Door (conventional door) 107 Rotation support member 108 Support shaft 109 Locking means (locking rod) L Bulging length at the center part (bulging height) M Width of the peripheral wall part О Center

Claims

1. A door that is detachably mounted so as to open or close an opening formed through in a predetermined direction, wherein the opening is formed in the top surface (ceiling portion) of the container, and the door has a surface that forms a bulging portion in which the center side bulges outward in the thickness direction with respect to the peripheral side in a front view, and is formed in a curved surface shape that gently inclines inward in the thickness direction from the bulging portion toward the periphery. One end side thereof is pivotally supported in the vertical direction on a support shaft disposed at or near the opening, and is provided with at least one rotation support member for assisting the rotation in the vertical direction, and the other end side is configured to be a free end, the rotation support member is composed of a rotation support member main body including a mounting portion formed in the center so as to be U-shaped, and a pair of coil portions composed of compression coil springs having a required length formed at both ends of the mounting portion, and mounting portions are formed at both end edges of the rotation support member, the pair of coil portions are respectively mounted on both ends of the outer peripheral portion of the support shaft, at least one of the mounting portions is attached to the door, the bulging length of the bulging portion is set to 10 to 20 mm characterized door.

2. The bulging length of the bulging portion is set to 10 to 12 mm characterized by the door according to claim 1.

3. The door is characterized by comprising a peripheral wall portion provided so as to hang down or stand up from its peripheral edge characterized by the door according to claim 1.

4. The shape of the door is in a front view, substantially circular, substantially elliptical, or substantially polygonal, and is selected from those in which all of these corners are rounded characterized by the door according to claim 1.

5. The door is characterized by comprising a locking projection projecting from the central portion in the length direction of the side surface on the free end side and engaging with locking means to lock the closing of the door, and a long rod-shaped reinforcing member disposed along the side surface on the free end side so as to extend along the edge of the end on the free end side characterized by the door according to claim 1.

6. characterized by comprising the door according to any one of claims 1 to 3 characterized container.

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