CONTAINER

Description

TECHNICAL FIELD

The present invention relates to containers used in cargo transportation, truck loading boxes, railway freight cars, and container houses.

BACKGROUND ART

The demand for freight transport is generally asymmetric between regions. Therefore, in freight transport using containers, containers often become empty on the outbound or return journey. Since containers occupy the same volume regardless of whether they are loaded with freight or not, a large number of empty containers are transported. In response to this problem, the applicant has proposed a container in which the container volume can be reduced to half or less when the container is empty by separating the container into upper and lower portions and making the posts provided at the four corners of the container foldable inward with the upper container or the lower container as an axis of rotation (Patent Document 1). On the other hand, in truck loading boxes, railway freight cars, container houses, etc., reducing the volume of containers when not in use is normally not considered.

PRIOR ART DOCUMENT

Patent Document

Patent Document 1:

Japanese Patent No. 6311850

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

An object of the present invention is to provide a container which has a reduced volume and improved transport efficiency when unladen.

Means for Solving the Problems

A container including: a pair of endwalls (14); a pair of sidewalls (12, 38, 42, 52); a top structure (16) and a bottom structure (18); a sidewall rotating means for folding the sidewalls (12, 38, 42, 52) under the top structure (16) or onto the bottom structure (18); an end frame (20) configured to surround four sides of the endwall (14); an endwall tilting means (28, 56) that enables the end frame (20) standing upright on the bottom structure (18) to be lifted and tilted towards the bottom structure (18), wherein the top structure (16) can be raised and lowered along corner posts (20A) between the upper end of the end frame (20) positioned upright and the floor of the bottom structure (18), and the endwall tilting means (28, 56) allows the endwall to be laid down on the top structure (16) which is put on the floor.

A recessed portion (32A) for accommodating an auxiliary post (32) being laid down is provided in the bottom structure (18) under the end frame (20) placed upright, and when the auxiliary post (32) is placed upright the tip end of the auxiliary post (32) extends to a position higher than the endwall (14) placed on top of the top structure (16). A connecting mechanism (26) for connecting containers (10) to each other is provided at the tip end of the auxiliary post (32).

The endwall tilting means (28, 56) may include a rotating shaft (28A) provided on the side of the bottom structure (18), and an arm (28) having one end supported by the rotating shaft (28A) and the other end fixed to the lower end of the corner post (20A), and the rotating shaft (28A) is located a predetermined distance (D) inward from the endwall (14) in the longitudinal direction.

The endwall tilting means (28, 56) may include an endwall guide (56) provided on the side of the bottom structure (18) with a guide groove (56A) along the vertical direction, and an endwall rotation shaft (14B) having one end engaged with the guide groove (56A) and the other end fixed to the lower end of the corner post (20A).

A sidewall engaging portion (56) that engages with the upper or lower end of the sidewall (12, 38, 42, 52) may be provided along the side of the top structure (16) or the bottom structure (18). Furthermore, sidewall storage section capable of storing the sidewalls (12, 38, 42) may be provided on the underside of the top structure (16), the upper side of the sidewall (12) is pivotally supported on the side of the top structure (16), and the left and right. sidewalls (12) are stacked and stored inside the top structure (16). The sidewall (38, 42) may be divided into an even number of panels, one above the other, so that the sidewall (38, 42) can be folded inward, and the left and right sidewalls (38, 42) are folded in parallel to each other. Furthermore, the corner posts may be provided with a locking mechanism (39) for preventing the top structure (16) from falling.

Effect of the Invention

According to the present invention, a container is provided which has a reduced volume and improved transport efficiency when unladen.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a schematic configuration of a container according to a first embodiment;

FIG. 2 is a perspective view showing a typical structure of a forklift engaging portion provided on a top structure of the container shown in FIG. 1 when collapsing the container;

FIG. 3 is a side view showing a schematic view of a container top being lowered, and a partially enlarged view showing the configuration of a mechanism for preventing the top structure from falling, which is provided on a corner post;

FIG. 4 is a perspective view showing the front and rear frames (corner posts) being folded together with the front and rear doors (endwalls);

FIG. 5 is a perspective view showing a schematic configuration of auxiliary posts used when stacking collapsed containers;

FIG. 6 is a perspective view showing a schematic configuration of a container according to a second embodiment;

FIG. 7 is a perspective view showing a schematic configuration in which sidewalls are stored in the container's top structure in a second embodiment;

FIG. 8 is a perspective view showing a schematic configuration of a container according to a third embodiment;

FIG. 9 is a perspective view showing a state when the collapsed containers are stacked;

FIG. 10 is a schematic perspective view of a container according to a fourth embodiment assembled at a first height;

FIG. 11 is a schematic cross-sectional view of a sidewall engaging portion;

FIG. 12 is a schematic cross-sectional view of a container according to a fourth embodiment;

FIG. 13 is a schematic perspective view of the container according to the fourth embodiment which is being folded from the first height;

FIG. 14 is a schematic perspective view of the container of the fourth embodiment folded to a second height;

FIG. 15 is a schematic perspective view showing the configuration of a groove of a sidewall-engaging portion corresponding to a corrugated steel plate, as viewed obliquely from below;

FIG. 16 is a schematic cross-sectional view of a sidewall-engaging portion of an alternate embodiment;

FIG. 17 is a partial schematic perspective view of a container according to a fifth embodiment;

FIG. 18 is a partial schematic perspective view of a container according to a fifth embodiment;

FIG. 19 is a partial schematic perspective view of a container according to an alternate embodiment of the fifth embodiment.

EMBODIMENT OF THE INVENTION

Hereafter, embodiments of the present invention are described with reference to the accompanying drawings. The container according to the present invention can be used not only as a shipping container (intermodal freight container) but also as a truck loading box or a railway freight car, and can also be used as a container house. Therefore, in the present specification and claims, the term container includes a shipping container, a truck freight box, railway freight car, and container house. FIG. 1 is a perspective view showing the general configuration of a container according to a first embodiment of the present invention.

The container 10 of the first embodiment includes a pair of left and right sidewalls 12, a pair of front and rear end walls 14, a top structure 16, and a bottom structure 18. As shown in FIG. 1, the sidewalls 12 are pivotally supported on the side of the top structure 16 via a hinge or the like (sidewall rotating means) and can be rotated toward the inside of the container. The height of the folded sidewalls 12 is less than the width of the top structure 16, and the sidewalls 12 that are rotated inward into the container can be stored inside a sidewall storage section provided on the bottom side of the top structure 16 from the bottom side. The left and right sidewalls 12 are rotated about axes at. different heights relative to the top structure 16 and are stacked alternately and stored within the top structure 16, and are fixed in the top structure 16 by a locking mechanism (not shown). The heights at which the left and right. sidewalls 12 are pivotally supported on the sides of the top structure 16 are determined according to the aspect ratio of the container 10, and in order to fold both sidewalls 12 alternately, the pivotal positions of the left and right sides may be set to different heights. For example, ISO standard containers have a width of 2438 mm and three optional heights H of 2896 mm, 2591 mm, or 2438 mm, so the pivotal heights for the sidewalls 12 are adapted to the selected dimension. When the left and right sidewalls 12 are upright, the lower edges of the sidewalls 12 can be fixed to the sides of the bottom structure 18 by a locking mechanism (not shown).

FIG. 2 is a schematic enlarged view of the top surface portion of the container 10. Note that the front end wall 14 is omitted in FIG. 2. A pair of forklift pockets 16A into which forks of a forklift are inserted are provided near the center of the top structure 16 in the longitudinal direction, spanning the left and right top side frames. The forklift pockets 16A are used when raising and lowering the top structure 16, which stores the sidewalls 12. The elevation of the top structure 16 is performed by the power of a forklift.

FIG. 3 is a side view showing how the top structure 16 is lowered. FIG. 4 is a diagram showing how the end wall 14 is pushed down onto the top structure 16 lowered onto the bottom structure 18. FIG. 4(a) shows a state in which the top structure 16 is lowered onto the floor while the front and rear end walls 14 are standing upright on the bottom structure 18. FIG. 4(b) shows a state in which only the front end wall 14 is folded over onto the bottom structure 18 while the rear end wall 14 is standing upright.

As shown in FIG. 4, the four sides of the end wall 14 are surrounded by an end frame 20, and a door 22, such as a double door, or an endwall panel 24 is attached to the inside of the end frame 20. The doors 22 may be provided at both the front and rear ends, or endwall panels 24 may be provided at both the front and rear ends, otherwise the door 22 may be provided on one side and the endwall panel 24 on the other side. Posts 20A supporting the top structure 16 are arranged on the left and right sides of the end frames 20, and the upper and lower ends of the posts 20A are connected through cross beams 20B. A connecting mechanism 26 is provided at the upper end of the post 20A to connect with a container stacked on top during a container operation. Incidentally, connecting mechanisms 26 are provided at the bottom surface of the bottom structure 18 corresponding to the positions of the posts 20A to connect with the container below. The connecting mechanisms 26 may have a structure similar to that of a conventional container.

The lower end of the post 20A is fixed to one end of an arm (endwall tilting means) 28, in which the other end of the arm 28 is pivotally supported on the side frame of the bottom structure 18. The rotation shaft 28A of the arm 28 provided on the side frame of the bottom structure 18 is located at a predetermined distance D from the center of the end frame 20, which is in the upright position, toward the center of the side frame along its longitudinal direction. The distance D is determined according to the thickness of the top structure 18 placed on the floor. Namely, the distance D is set to a value at which the end frame 20 is lifted so that the endwall 14 closely fits on the top face of the top structure 16 when the endwall 14 is folded onto the bottom structure 18 by rotating the end frame 20 about the rotation shaft 28A.

When the end frames 20 are upright, the top structure 16 is interposed between the front and rear end frames 20. As shown by the solid line in FIG. 3, the top structure 16 is positioned at the upper end of the end frame 20 (first height) when loading cargo. On the surface of the post 20A that makes contact with the top structure 16A, locking mechanisms 30 are provided at every predetermined height. The locking mechanism 30 has a latch bolt structure in which a claw pushed outward from the post 20A by the biasing force of a spring or the like engages with the top structure 16 to prevent it from falling, and the claw is pushed back into the post 20A when the top structure 16 is being raised.

When used at the first height, the top structure 16 is supported by the locking mechanism 30, and its end is fixed to the upper end of the post 20A by a locking mechanism (not shown). At this time, the upright end frame 20 is fixed to the frame of the bottom structure 18 by a locking mechanism (not shown). When the top structure 16 is lowered to the position where it makes contact with the bottom structure 18 (second height), the locking mechanism 30 is retracted in the post 20A by a locking release mechanism (not shown).

As shown in FIG. 5, auxiliary posts 32 are provided on the frame of the bottom structure 18 at positions beneath the posts 20A in the upright position. The auxiliary post 32 can be tilted inward in the container lateral direction. When the end frame 20 is made upright, the auxiliary post 32 is accommodated in a recessed portion 32A provided in the frame of the bottom structure 18. As shown in FIG. 4(b), when the endwall 14 is folded onto the top structure 16 placed on the bottom structure 18, the auxiliary posts 32 can be made upright. The upright auxiliary post 32 can be fixed in its position by a locking mechanism (not shown).

A connecting mechanism 34 having the same function as the connecting mechanism 26 is provided at the upper end of the auxiliary post 32. When the container 10 is fully folded, that is, when the front and rear endwalls 14 are folded onto the top structure 16 and fixed to the bottom structure 18 by a locking mechanism (not shown), and the auxiliary posts 32 are erected, the connecting mechanism 34 is located at position slightly higher than the endwalls 14 stacked on the top structure 16. As shown in FIG. 9, when the folded containers 10 are stacked, the connecting mechanism 34 is engaged with and fixed to the connecting mechanism 26 provided on the bottom structure 18 of the upper container 10. The above-mentioned configuration is the same in the other embodiments.

On the other hand, unfolding the container 10 folded to the second height, then assembling it to the first height, the above-mentioned folding work is performed in reverse. That is, after the front and rear endwalls 14 are made upright, the top structure 16 is lifted to the first height by a forklift and fixed to the end frames 20, and then the left and right sidewalls 12 are unfolded, further, the sides of the container 10 are sealed and the sidewalls are fixed to the end frames 20 and the bottom structure 18. It is also possible to provide rounded corners for both ends of the frame on the endwall 14 side of the top structure 16, so that when the top structure 16 is lifted, the endwalls 14 stand up by contact with the top structure 16 that is being lifted. In this case, it is preferable to apply a surface treatment or use a special material for the contact part of the top structure 16 with the end frame 20 regarding wear resistance and low friction. Examples of surface treatments include a coating (such as dichroic coating) and plating (such as electroless nickel plating and hard chrome plating), and examples of special materials include ABREX™, HARDOX™, and EVERHARD™.

Furthermore, when loading or unloading cargo into or from a container 10, operations may be carried out from the side of the container 10 by maintaining the top structure 16 at the first height and retracting one or both of the left and right sidewalls 12 within the top structure 16.

As described above, according to the container of the first embodiment, the volume of the empty container can be further reduced, and as a result, the transport efficiency of the empty container is improved. In addition, it can be provided as a simple configuration, and the collapsing operation of the container can be easily carried out by a few operators. Furthermore, by using the auxiliary posts, the collapsed empty containers can be safely stacked in the same manner as conventional containers.

Next, the configuration of the container 36 of the second embodiment will be described with reference to FIG. 6, which is a perspective view showing the general configuration of the container 36, and FIG. 7, which is an enlarged view of the top surface of the container 36. Note that the endwall 14 on the front side is omitted in FIG. 7. The container 36 of the second embodiment has substantially the same configuration as the container 10 of the first embodiment but differs in the structure of the sidewalls 12. The same reference numerals are used for the same configuration as the first embodiment, and the description thereof will be omitted.

The sidewall 38 of the second embodiment is divided into a plurality of (even number of) panels in the vertical direction and each of the panels is connected by a hinge. The panels can be folded in an accordion-like manner toward the inside of the container 36. In the example of FIG. 6, the sidewall 38 is divided into two panels, upper and lower panels 38A and 38B. The upper side of the upper panel 38A is pivoted to the side of the top structure 16, and the lower side is connected to the upper side of the lower panel 38B via a hinge. Both ends of the lower side of the lower panel 38B are configured to be movable along guide grooves or the like provided along the posts 20A. The upper and lower panels 38A and 38B are folded toward the inside of the container 36 via the folding operation. When the lower side of the lower panel 38B reaches the height of the top structure 16, the upper and lower panels 38A and 38B are stored inside the top structure 16 in a folded state. The folded left and right sidewalls 38 are sized so as not to interfere with each other inside the top structure 16. When the panel is divided into four or more panels, both ends of the lower side of the even-numbered panels from the top are configured to be movable along the posts 20A.

As described above, the container of the second embodiment can provide the same effects as those of the first embodiment. In the second embodiment, the lower side of the lower panel 38B is made detachable from the frame of the bottom structure 18, and the sidewall 38 is folded and lifted up to be stored in the top structure 16. However, the lower side of the lower panel 38B can also be pivotally supported on the side of the frame of the bottom structure 18. In this case, the sidewalls 38 are folded as the top structure 16 descends and are stored inside the top structure 16 when the top structure 16 comes into contact with the bottom structure 18. This eliminates the need for a locking mechanism for fixing the upper and lower panels 38A, 38B inside the top structure 16.

Next, a container according to a third embodiment will be described with reference to FIG. 8. The container according to the third embodiment differs from the first embodiment in the configuration of its sidewalls, as in the second embodiment. The other configurations are the same as those in the first and second embodiments, and the same reference numerals are used for the same configurations, and the description thereof will be omitted.

The sidewall 42 of the container 40 of the third embodiment is divided into a plurality of (even number of) panels 42A, 42B connected by hinges as in the second embodiment, and a drop-side panel 42C completely separated from the panels 42A, 42B. The panels 42A, 42B have the same configuration as the panels 38A, 38B of the second embodiment. The lower side of the panel 42C is pivotally supported on the side of the bottom structure 18, and can rotate inward or outward from the container 40. When the top structure 16 is fixed at the first height, the panels 42A, 42B, 42C are erected, and the lower side of the panel 42B and the upper side of the panel 42C are fixed by a locking mechanism (not. shown). When the top structure 16 is lowered onto the bottom structure 18 to collapse the container 40, the panels 42A, 42B are folded and stored inside the top structure 16, and the panel 42C is folded over onto the floor of the bottom structure 18. When loading or unloading the container 40 with the sidewall 42 open, the panel 42C is rotated to the outside of the container 40.

As described above, the container of the third embodiment can also provide the same effects as those of the first and second embodiments.

Next, a container according to the fourth embodiment will be described with reference to FIGS. 10 to 15. FIG. 10 is a perspective view of a container 50 according to the fourth embodiment, which is assembled to a first height. The container 50 according to the fourth embodiment has a structure in which the left and right sidewalls 52 are folded inward along the sides of the bottom structure 18. The sidewalls 52 can be alternately tipped over the bottom structure 18 along the sides of the bottom structure 18 via hinges and the like. In addition, the top structure 16 of the container 50 is provided with sidewall-engaging portions 54 along the lower surfaces of the respective sides. The other configurations are substantially similar to those of the first to third embodiments, and the same reference numerals are used for the similar configurations, and the description thereof will be omitted.

As shown in the cross-sectional view of FIG. 11, the sidewall-engaging portion 54 is provided with a groove 54A capable of accommodating the upper end of the sidewall 52. The upper end of the sidewall 52 is water-tightly fitted into the groove 54A of the sidewall-engaging portion 54 by raising and lowering the top structure 16 (for example, a seal member 54B is provided in the groove 54A). The sidewall-engaging portion 54 partially plays the role of a sidewall in the upper portion of the container, so that the height of the sidewall 52 is less than the width W. Furthermore, the lower ends of the left and right sidewalls 52 are pivotally supported about rotation axes L1 and L2 provided at different. heights relative to the bottom structure 18. With the above configuration, the left and right sidewalls 52 can be folded alternately on top of the floor of the bottom structure 18, as shown in the cross-sectional view of FIG. 12.

When collapsing the container 50 with the top structure 16 assembled at the first height to the second height, the top structure 16 is lifted by a lifting device such as a forklift, and the upper ends of the sidewalls 52 are removed from the grooves 54A of the sidewall-engagement portions 54, as shown in the perspective view of FIG. 13. Then, each sidewall 52 is folded over onto the floor of the bottom structure 18. Next, as shown in the perspective view of FIG. 14, the top structure 16 is placed on the sidewalls 52 folded over onto the bottom structure 18 via a lifting device such as a forklift, and the front and rear endwalls 14 are folded over onto the top structure 16, which is placed on the sidewalls 52, and the auxiliary posts 32 are erected, as in the first to third embodiments.

Incidentally, when a corrugated steel plate is used for the sidewall 52, the groove 54A is also structured to correspond to the corrugation of the sidewall 52 as shown in FIG. 15, and the upper end portion of the sidewall 52 fits snugly and watertightly into the groove 54A.

As shown in the cross-sectional view of FIG. 16, a sidewall-engaging portion 55 having an L-shaped cross section, which is an alternative embodiment of the sidewall-engaging portion 54, may be used by removing the side portion inside the groove 54A of the sidewall-engaging portion 54. In this embodiment, the sidewalls 52 can be operated before lifting up the top structure 16.

As described above, the container of the fourth embodiment can obtain the same effects as those of the first to third embodiments, and can ensure greater watertightness. Incidentally, the configuration of the sidewall-engaging parts 54, 55 of the fourth embodiment can also be applied to the bottom structure 18 of the first embodiment. In the fourth embodiment, grooves similar to the sidewall-engaging parts may be provided along the sides of the bottom structure 18 so that the lower ends of the sidewalls 52 can be slightly fitted to the bottom structure 18 in a watertight manner.

FIGS. 17 and 18 are partial perspective views of a container according to the fifth embodiment. In the first to fourth embodiments, substantially L-shaped arms 28 are used as the endwall tilting means, but in the fifth embodiment, endwall guides 56, which will be described later, are used. Note that other configurations are substantially similar to those of the fourth embodiment, etc., and the same reference numerals are used for similar configurations, and descriptions thereof will be omitted.

FIG. 17 is a perspective view of the area around the endwall guide 56 when the container is assembled at the first height. FIG. 18 shows the state when the sidewalls 52 are folded onto the bottom structure 18 and the top structure 16 is placed on top of the folded sidewalls 52, and furthermore, the endwall 14 is guided by the endwall guide 56 and folded onto the top structure 16.

The endwall guide 56 includes a long plate member having a slit guide groove 56A extending in the longitudinal direction (vertical direction) in its center. An endwall-rotating shaft 14B protruding outward is provided at each lower end of the corner post 20A of the endwalls 14. The endwall guide 56 is fixed to the bottom structure 18 so as to be disposed along the outside of each corner post 20A, and the endwall-rotating shaft 14B is engaged with each guide groove 56A. This allows the endwall-rotating shaft 14B to move up and down within the guide groove 56A.

As shown in FIG. 18, when the left and right sidewalls 52 are folded onto the bottom structure 18 and the top structure 16 is placed on the folded sidewalls 52, the endwall 14 (end frame 20) is lifted while maintaining an upright position using a lifting device such as a forklift. At this time, the endwall-rotating shaft 14B is moved along the guide groove 56A while the endwall 14 is kept upright. When the endwall-rotating shaft 14B reaches the upper end of the guide groove 56A, the endwall 14 is folded onto the top structure 16 that has been lowered to the second height, with the endwall-rotating shaft 14B as the rotating shaft. Here, the length of the guide groove 56A corresponds approximately to the predetermined distance D, for example.

In addition, guide posts (not shown) may be provided at the four corners of the bottom structure 18 to hold the endwall 14 upright on the bottom structure 18 and guide the lifting and lowering of the endwalls 14 in the upright state. The guide posts, for example, protrude vertically upward from the four corners of the bottom structure 18 and engage with each of the corner posts 20A. The guide post members are shorter than the distance D and are inserted into guide holes provided inside the corner posts 20A along the longitudinal direction. When the endwall 14 is upright on the bottom structure 18, the guide posts are fitted into the guide holes from the bottom surface of the corner posts 20A. When the endwall 14 (corner posts 20A) is lifted vertically, the corner posts 20A are moved along the guide posts while maintaining its upright position, and when the endwall-rotating shafts 14B reach the upper end of the guide grooves 56A, the guide posts are completely removed from the guide holes so that the endwall 14 becomes rotatable inward into the container about the endwall-rotating shaft 14B.

Furthermore, the end frame 20 is provided with an endwall lift member 14A at an appropriate predetermined position, and when folding the endwall 14, a wire is hooked to the endwall lift member 14A and the endwall 14 is lifted by a lifting device such as a forklift. In the example of FIG. 17 and FIG. 18, the endwall lift member 14A is provided at two locations on the left and right of the lower cross beam 20B, but the endwall lift member 14A may be provided on the left and right corner posts 20A or the upper cross beam 20B, or may be provided at multiple heights of the endwall 14. Furthermore, as long as it is of sufficient strength, the endwall lift member 14A may be provided at a location other than the end frame 20.

FIG. 19 is a partial perspective view of a container showing the configuration of an alternate embodiment of the fifth embodiment. In the fifth embodiment, the endwall guide 56 is disposed on the outside of the corner post 20A (outside the frame of the bottom structure 18), but in the alternate embodiment, it is provided adjacent to the corner post 20A on the frame of the bottom structure 18. For example, an L-shaped endwall-rotating shaft. 15, which engages with a guide groove 56A of the endwall guide 56, is provided at the lower end of the corner post 20A. For example, one end of the L-shaped endwall-rotating shaft 15 is provided on the inner surface of the corner post 20A in the container longitudinal direction and extends along the container longitudinal direction, then the other end of the endwall-rotating shaft 15 is bent 90 degrees outward to engage with the guide groove 56A. Thereby, the endwall-rotating shaft 15 can be raised and lowered along the guide groove 56A, and the endwall can be folded over the top structure 16 lowered to the second height about the endwall-rotating shaft 15, as the rotation axis, at the upper end of the guide groove 56A. The shape of the endwall-rotating shaft 15 is not limited to that of this embodiment as long as it serves as a rotating shaft, and for example, it may be U-shaped. In such case, both ends of the U-shaped shaft are attached to the corner post 20A. The installation position of the U-shaped shaft to the corner post 20A is also not limited to that of this embodiment. In this alternate embodiment, the endwall-rotating shaft 15 and the endwall guide 56 are disposed outside the recessed portion of the sidewall 52, which is a corrugated steel plate.

As described above, the fifth embodiment can also provide the same effects as the first to fourth embodiments.

When the container of the present embodiments is applied as a truck loading box or a railroad freight car, it can be detachable with respect to the chassis of the truck or freight car, but it can also be used in a permanently installed state.

The configuration of each part described in each embodiment can be applied independently to other embodiments as long as there is no structural contradiction. For example, the configuration of dividing the sidewall into a plurality of panels in the second and third embodiments can also be applied to the sidewall in the fourth and fifth embodiments. The configuration of the endwall tilting means can also be replaced in each embodiment, and other configurations can also be replaced as long as there is no structural contradiction.