An open car lower side door and open car

Abstract

The utility model discloses a kind of open wagon lower side door and open wagon, open wagon lower side door includes: lower side door panel (100), the lower side door panel (100) is made of composite material, the lower side door panel (100) has opposite outer side and inner side, the lower side door panel (100) includes the first protruding area (101) and the second protruding area (102) that protrude from the outer side and are relatively independent, the first protruding area (101) is set along the outer periphery of the lower side door panel (100) and the second protruding area (102) is located in the first protruding area (101);Hinge (200), the hinge (200) is connected with the outer side of the lower side door panel (100);Thickening layer, the thickening layer is set to the inner side and is set corresponding with the first protruding area (101) and / or the second protruding area (102).The utility model discloses open wagon lower side door, reduce weight and reduce goods leakage probability.

Description

Technical Field

[0001] This utility model relates to the field of vehicle equipment technology, and in particular to a lower side door of a wagon and a wagon itself. Background Technology

[0002] Open wagons are the main type of freight car on my country's railways, accounting for about 60-70% of the total number of freight cars. This type of wagon is used to transport a variety of goods such as coal, timber, steel coils, and containers.

[0003] Currently, the lower side door of open wagons is mainly made of carbon steel and consists of door panels, hinges, etc. Its disadvantage is that it is heavy and it is difficult to operate the lower side door manually. Therefore, some work sites use mechanical equipment to lift the lower side door, which can easily cause collision and deformation to the lower side door.

[0004] Non-metallic materials can be used to make the lower door panel, but this will undoubtedly reduce the rigidity of the lower door panel. Under the pressure of the cargo inside the vehicle, the lower door panel is prone to deformation, which will increase the gap between the edge of the lower door panel and the vehicle body, causing cargo leakage.

[0005] Therefore, how to reduce weight and the probability of cargo leakage is a problem that urgently needs to be solved by those in this technical field. Utility Model Content

[0006] In view of this, the present invention provides a lower side door for open wagons to reduce weight and the probability of cargo leakage.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A convertible lower side door, comprising:

[0009] The lower door panel is made of composite material and has an outer side and an inner side facing away from each other. The lower door panel includes a first protruding area and a second protruding area that protrude from the outer side and are relatively independent. The first protruding area is arranged along the outer periphery of the lower door panel and the second protruding area is located within the first protruding area.

[0010] A hinge, wherein the hinge is connected to the outer side surface of the lower door panel;

[0011] A thickened layer is disposed on the inner side surface and corresponds to the first protruding area and / or the second protruding area.

[0012] Optionally, in the aforementioned convertible lower side door, the thickening layer includes a first thickening layer disposed in the first protruding area, the edge of the first thickening layer being aligned with the edge of the lower side door panel.

[0013] Optionally, in the lower side door of the aforementioned convertible, along the arrangement direction of the outer and inner sides, the projection structure of the first thickened layer is a rectangular structure with a length of L2 and a width of H2.

[0014] Optionally, in the aforementioned convertible lower side door, the thickening layer further includes a third thickening layer disposed on the side of the first thickening layer facing away from the lower side door panel;

[0015] Along the arrangement direction of the outer and inner sides, the projection structure of the first thickened layer is a rectangular structure with a length of L3 and a width of H2, where L3 < L2, and the third thickened layer is located in the middle of the first thickened layer in the length direction.

[0016] Optionally, in the aforementioned convertible lower side door, the number of the first thickened layers is multiple and arranged circumferentially along the first raised area.

[0017] Optionally, in the aforementioned convertible lower side door, the thickened layer includes a second thickened layer disposed in the second protruding area; along the arrangement direction of the outer side and the inner side, the projected structure of the second thickened layer is a rectangular structure.

[0018] Optionally, in the lower side door of the aforementioned convertible, along the arrangement direction of the outer and inner sides, the projected edge of the second thickened layer is located outside the edge of the second protruding area.

[0019] Optionally, in the aforementioned convertible lower side door, the hinge includes a hinge body connected to the lower side door panel and a rib located on the side of the hinge body facing away from the lower side door panel;

[0020] Wherein, the fold satisfies at least one of the following:

[0021] The hinge body is a multi-layer composite material layer stacked together. The hinge body has a pin hole end and a fastening end facing away from each other. The pin hole end is bent away from the lower door panel to form a pin hole portion. Multiple material layer ends of the pin hole end are arranged sequentially towards the pin hole portion in a direction away from the lower door panel. And / or, the fastening end has an auxiliary material layer stacked with the multi-layer composite material layer.

[0022] The cross-section of the fold is a "T" shaped cross-section, and the fold body is perpendicular to the rib.

[0023] The hinge includes a first composite material layer and a second composite material layer. The second composite material layer has a first portion and a second portion arranged at an angle. The first portion is superimposed on the first composite material layer to form the hinge body, and the second portion forms the rib.

[0024] Optionally, the lower side door of the aforementioned convertible meets at least one of the following conditions:

[0025] The hinge and the lower door panel are an integral structure, or the hinge and the lower door panel are connected by a connecting structure;

[0026] The hinge and the lower door panel are made of fiber-reinforced resin-based composite material;

[0027] The cross-section of the first protruding region is a trapezoidal structure;

[0028] The thickened layer is made of the same material as the lower door panel.

[0029] This utility model also provides a convertible, including a body and a convertible lower side door disposed on the body, wherein the convertible lower side door is any of the convertible lower side doors described above.

[0030] As can be seen from the above technical solution, the open wagon lower side door provided by this utility model effectively reduces the weight of the lower side door panel by using composite materials, thereby reducing the overall weight of the open wagon lower side door. This facilitates manual operation of the open wagon lower side door for opening and closing, and reduces the possibility of deformation of the open wagon lower side door due to collisions. Furthermore, the first and second protruding areas of the lower side door panel protrude from the outer side, thus preventing compression of cargo inside the vehicle. Since the hinge is connected to the outer side of the lower side door panel, a thickened layer can be provided on the inner side of the lower side door panel without affecting the hinge's function. Because the first protruding area is located along the outer periphery of the lower side door panel and the second protruding area is located within the first protruding area, the strength of the first and / or second protruding areas is improved by providing corresponding thickened layers, thereby increasing the rigidity of the lower side door panel and reducing the deformation of the lower side door panel under the pressure of cargo inside the vehicle. This avoids excessive gaps between the edge of the lower side door panel and the vehicle body, effectively reducing the probability of cargo leakage.

[0031] The open wagon provided by this utility model has the aforementioned open wagon lower side door, and therefore has the same technical effect as the aforementioned open wagon lower side door, and is not specifically limited here. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the main structure of the lower side door of a convertible provided in an embodiment of the present utility model;

[0034] Figure 2 A side view of the lower side door of a convertible provided in an embodiment of this utility model;

[0035] Figure 3 This is a schematic diagram of the main structure of the lower door panel provided in an embodiment of the present utility model;

[0036] Figure 4 for Figure 3 A partial sectional view of AA;

[0037] Figure 5 for Figure 3 A partial sectional view of BB;

[0038] Figure 6 A side view of the folding structure provided for an embodiment of this utility model;

[0039] Figure 7 This is a schematic diagram of the main view structure of the folding page provided in an embodiment of the present utility model;

[0040] Figure 8 A first cross-sectional schematic diagram of a folding mechanism provided in an embodiment of this utility model;

[0041] Figure 9 This is a second cross-sectional schematic diagram of the folding mechanism provided in an embodiment of the present invention;

[0042] Figure 10 A third cross-sectional schematic diagram of the folding mechanism provided in this embodiment of the utility model;

[0043] Figure 11 This is a fourth cross-sectional schematic diagram of the folding mechanism provided in an embodiment of the present invention.

[0044] in,

[0045] The lower door panel 100 has a first raised area 101, a second raised area 102, a first thickened layer 110, a second thickened layer 120, and a third thickened layer 130.

[0046] Fold 200, fold body 210, first composite material layer 2101, second composite material layer 2102, multi-layer composite material layer 211, pin hole 212, snap fastener end 213, filling area 214, first intermediate area 215, rib 220, rib bottom surface 221, rib side surface 222, second intermediate area 223. Detailed Implementation

[0047] This utility model discloses a lower side door for open wagons to reduce weight and the probability of cargo leakage. This utility model also provides an open wagon.

[0048] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0049] like Figures 1-5 As shown, this utility model embodiment provides a lower side door for a convertible, including a lower door panel 100, a hinge 200, and a thickening layer. The lower door panel 100 is made of composite material and has an outer side and an inner side facing away from each other. The lower door panel 100 includes a first protruding area 101 and a second protruding area 102 protruding from the outer side and relatively independent. The first protruding area 101 is disposed along the outer periphery of the lower door panel 100, and the second protruding area 102 is located within the first protruding area 101. The hinge 200 is connected to the outer side of the lower door panel 100. The thickening layer is disposed on the inner side and corresponds to the first protruding area 101 and / or the second protruding area 102.

[0050] The convertible lower door provided in this embodiment of the invention effectively reduces the weight of the lower door panel 100 by using composite materials, thereby reducing the overall weight of the convertible lower door. This facilitates manual operation of the convertible lower door for opening and closing and reduces the likelihood of deformation of the convertible lower door due to collisions. Furthermore, the first protruding area 101 and the second protruding area 102 of the lower door panel 100 protrude from the outer side, thus preventing compression of cargo inside the vehicle. Since the hinge 200 is connected to the outer side of the lower door panel 100, a thickened layer can be provided on the inner side of the lower door panel 100 without affecting the function of the hinge 200. Since the first protruding area 101 is provided along the outer periphery of the lower door panel 100 and the second protruding area 102 is located within the first protruding area 101, by providing thickened layers corresponding to the first protruding area 101 and / or the second protruding area 102, the strength of the first protruding area 101 and / or the second protruding area 102 is improved, thereby increasing the rigidity of the lower door panel 100 and reducing the deformation of the lower door panel under the pressure of cargo inside the vehicle. This avoids the situation where the gap between the edge of the lower door panel 100 and the vehicle body is too large, effectively reducing the probability of cargo leakage.

[0051] The convertible lower side door provided in this embodiment of the utility model achieves a balance between weight and rigidity by using composite material to make the lower side door panel 100, and by adding a thickened layer to the inner side of the lower side door panel 100 corresponding to the first protruding area 101 and / or the second protruding area 102. That is, while meeting the rigidity requirements, the weight of the convertible lower side door is reduced as much as possible.

[0052] Furthermore, by providing thickened layers corresponding to the first protruding region 101 and / or the second protruding region 102, the thickened layers are at least partially embedded in the grooves formed on the inner side of the first protruding region 101 and / or the second protruding region 102, thereby reducing the impact on the cargo inside the vehicle.

[0053] Figure 4 and Figure 5 In the figure, the outer side of the lower door panel 100 is the left side of the lower door panel 100, and the inner side of the lower door panel 100 is the right side of the lower door panel 100.

[0054] In some embodiments, the thickening layer includes a first thickening layer 110 disposed in the first protruding region 101, the edge of the first thickening layer 110 being aligned with the edge of the lower door panel 100. This configuration effectively strengthens the edge of the lower door panel 100, further preventing an increase in the gap between the lower door panel 100 and the vehicle body due to edge deformation, thereby reducing the probability of cargo leakage.

[0055] To facilitate the processing of the first thickened layer 110 and its connection with the first protruding area 101 of the lower door panel 100, the projection structure of the first thickened layer 110 is a rectangular structure with a length of L2 and a width of H2 along the arrangement direction of the outer and inner sides.

[0056] like Figure 3 As shown, in some embodiments, the first protruding region 101 can be a rectangular frame structure with rounded corners. Each side of the rectangular frame structure can be a certain distance from the edge of the lower door panel 100, wherein the width of each side of the rectangular frame structure is less than H2. L2 can be the size of the straight-line region of at least one side of the first protruding region 101, and H2 can be the sum of the width of the first protruding region 101 and the distance between the first protruding region 101 and the edge of the lower door panel 100.

[0057] The thickening layer may further include a third thickening layer 130 disposed on the side of the first thickening layer 110 facing away from the lower side door panel 100. That is, the area of ​​the first protruding region 101 where the first thickening layer 110 is disposed is further thickened by the third thickening layer 130. The first thickening layer 110 has a rectangular structure with a length of L3 and a width of H2, where L3 < L2, and the third thickening layer 130 is located at the midpoint of the first thickening layer 110 along its length.

[0058] The number of first thickened layers 110 can be multiple and arranged circumferentially along the first protruding region 101. Taking the first protruding region 101 as an example, it can be a rectangular frame structure with four sides, and each side can be provided with a corresponding first thickened layer 110.

[0059] Alternatively, the first thickened layer 110 can be configured as a structural layer that matches the structure of the first protruding region 101. For example, the first thickened layer 110 can be configured as a rectangular frame structural layer, which is connected to the corners (four sides and rounded corners) of the first protruding region 101 respectively.

[0060] In some embodiments, the thickening layer includes a second thickening layer 120 disposed in the second protruding region 102; the projected structure of the second thickening layer 120 is a rectangular structure along the arrangement direction of the outer and inner sides. The projected edge of the second thickening layer 120 is located outside the edge of the second protruding region 102 along the arrangement direction of the outer and inner sides. Through the above arrangement, the strength of the middle region of the lower door panel 100 is effectively strengthened, further preventing the increase of the gap between the lower door panel 100 and the vehicle body due to edge displacement caused by deformation of the middle of the lower door panel 100, thereby reducing the probability of cargo leakage.

[0061] The second protruding region 102 has a length of L1 and a width of H1. Along the arrangement direction of the outer and inner sides, the projected edge of the second thickened layer 120 is located outside the edge of the second protruding region 102; that is, the length of the second thickened layer 120 is greater than L1, and the width of the second thickened layer 120 is greater than H1. In other words, the second thickened layer 120 can completely cover the second protruding region 102 and extends outward (towards the edge of the lower door panel 100) by a certain dimension, effectively improving the rigidity of the second protruding region 102.

[0062] The first thickening layer 110, the second thickening layer 120, and the third thickening layer 130 can be a single-layer structure or a multi-layer structure. The laying angle of the first thickening layer 110, the second thickening layer 120, and the third thickening layer 130 can be one or more of 0°, ±45°, and / or 90°, so as to match the structure of the raised area.

[0063] like Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the hinge 200 includes a hinge body 210 connected to the lower door panel 100 and a rib 220 located on the side of the hinge body 210 facing away from the lower door panel 100.

[0064] The hinge body 210 includes multiple layers of composite material 211 stacked together. The hinge body 210 has opposing pin hole ends and latching ends 213. The pin hole ends are bent away from the lower door panel 100 to form a pin hole portion 212. Multiple material layer ends at the pin hole ends are arranged sequentially towards the pin hole portion 212 in a direction away from the lower door panel 100. These multiple material layer ends are the ends of each composite material layer in the multiple composite material layer 211 located at the pin hole end. By arranging the multiple material layer ends at the pin hole ends sequentially towards the pin hole portion 212 in a direction away from the lower door panel 100, a sloping structure with a uniform transition is achieved at the pin hole ends. Since the pin hole portion 212 is bent away from the lower door panel 100, its wall thickness is twice the thickness of the multiple composite material layer 211, and the pin hole portion 212 can be formed without delaminating the multiple composite material layer 211, effectively improving the strength of the pin hole portion 212. That is, the strength of the pin hole 212 can be guaranteed without adding an auxiliary thickening layer inside or outside the pin hole 212. Of course, an additional thickening layer can be added inside or outside the pin hole 212. The inner side of the overlapping portion of the pin hole 212 can be a filling area 214, which improves the structural stability of the pin hole 212 by filling with resin or other filler materials. The pin hole end can rotate with the vehicle body through the pin hole 212, and the latch end 213 can be fastened to the vehicle body.

[0065] The snap fastener 213 may also have an auxiliary material layer superimposed on the multi-layer composite material layer 211. That is, an additional auxiliary material layer is added, so that the number of material layers in the snap fastener 213 is greater than the number of material layers in the hinge body 210. The number of auxiliary material layers can be multiple and gradually increase in thickness in the snap fastener 213.

[0066] In some embodiments, the hinge 200 has a T-shaped cross-section, and the hinge body 210 is perpendicular to the rib 220. For example... Figure 6 As shown, the bottom surface 221 of the rib 220 is connected to the folding body 210, and the side surface 222 of the rib 220 is perpendicular to the folding body 210. This arrangement effectively increases the strength of the folding body 210.

[0067] like Figure 6 and Figure 8 As shown, the hinge 200 includes a first composite material layer 2101 and a second composite material layer 2102. The second composite material layer 2102 has a first part and a second part arranged at an angle. The first part is superimposed with the first composite material layer 2101 to form a hinge body 210, and the second part forms a rib 220.

[0068] like Figure 8As shown, there are two sets of second composite material layers 2102 arranged symmetrically. The two sets of second composite material layers 2102 and the first composite material layer 2101 form a first intermediate region 215. The first intermediate region 215 can be used to fill with filler materials such as resin.

[0069] like Figure 9 As shown, the second composite material layer 2102 is an integral structure, with a middle bend forming a second part and a second intermediate region 223. The first part and the first composite material layer 2101 together form a first intermediate region 215. The first intermediate region 215 and the second intermediate region 223 can be used to fill with filler materials such as resin.

[0070] like Figure 10 As shown, the end of the rib 220 away from the first composite material layer 2101 can be a bent portion, that is, the end of the rib 220 is bent by bending along one side in the second part.

[0071] like Figure 11 As shown, the end of the rib 220 away from the first composite material layer 2101 can be a "T" shaped end. There are two sets of second composite material layers 2102 arranged symmetrically. Both ends of the two sets of second composite material layers 2102 have bent structures, so that each set of second composite material layers 2102 forms a "C" shaped structure. The two sets of second composite material layers 2102 are arranged symmetrically so that one side of each set forms a first intermediate region 215, and the other side forms a second intermediate region 223. The first intermediate region 215 and the second intermediate region 223 can be used to fill with resin or other filler materials.

[0072] Other structures can also be made for the cross-section of the hinge 200; no specific restrictions are imposed here, and all are within the scope of protection.

[0073] Furthermore, the hinge 200 and the lower door panel 100 are an integral structure, or the hinge 200 and the lower door panel 100 are connected by a connecting structure.

[0074] Preferably, the hinge 200 and the lower door panel 100 are made of fiber-reinforced resin matrix composite material. Other materials can also be used. The density of fiber-reinforced resin matrix composite material is generally 1.6–2.2 kg / m³. 3 The density of the original steel structural material was 7.8 kg / m³. 3 The density of the structural material in the technical solution of this invention is about one-quarter of that of the original structural material, thus significantly reducing the structural weight and achieving lightweighting of the lower side door. At the same time, the resin-based material has good chemical stability, which improves the corrosion resistance of the lower side door.

[0075] The thickness of the lower door panel 100 can be 6 to 10 mm, and the four corners of the lower door panel 100 are rounded.

[0076] During the thickening process of the first raised area 101 and / or the second raised area 102, according to design requirements (rigidity requirements), after each part is laid to the designed thickness, it is cured using a hot autoclave or molding process to connect the thickened layer to the lower door panel 100. Furthermore, during the processing of the hinge 200, prepreg or other materials can be used for overall laying and end-to-end thickening with composite material layers according to a specified sequence. After laying, it is cured using a hot autoclave or molding process. Alternatively, a pultrusion process can be used to facilitate mass production and reduce manufacturing costs.

[0077] To improve the maintainability of the lower side door of the convertible, the lower door panel 100 and the hinge 200 can be separately cured and then connected to each other using detachable rivets or clips, allowing for individual replacement of the lower door panel 100 and the hinge 200. After the lower door panel 100 and the hinge 200 are assembled, a high-strength, wear-resistant, and anti-corrosion coating can be sprayed onto the inner surface of the lower door panel 100 to further improve its impact resistance.

[0078] like Figure 5 As shown, the cross-section of the first protruding region 101 can be a trapezoidal structure. Of course, the cross-section of the first protruding region 101 can also be other structures, such as triangular or arc-shaped structures. No specific limitations are imposed here, and all are within the scope of protection.

[0079] The thickened layer is made of the same material as the lower door panel 100. That is, the thickened layer can be made of fiber-reinforced resin-based composite material.

[0080] This utility model embodiment also provides a convertible, including a body and a lower convertible door disposed on the body, wherein the lower convertible door is any of the convertible lower doors described above. Since the aforementioned lower convertible door has the above-described technical effects, a convertible with the aforementioned lower convertible door should also have the same technical effects, and no specific limitations are made here.

[0081] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0082] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A lower side door of a convertible, characterized in that, include: The lower door panel (100) is made of composite material and has an outer side and an inner side facing away from each other. The lower door panel (100) includes a first protruding area (101) and a second protruding area (102) that protrude from the outer side and are relatively independent. The first protruding area (101) is arranged along the outer periphery of the lower door panel (100) and the second protruding area (102) is located within the first protruding area (101). A hinge (200) is connected to the outer side of the lower door panel (100); A thickened layer is disposed on the inner side and corresponds to the first protruding area (101) and / or the second protruding area (102).

2. The lower side door of the open wagon as described in claim 1, characterized in that, The thickened layer includes a first thickened layer (110) disposed in the first protruding area (101), the edge of the first thickened layer (110) being aligned with the edge of the lower door panel (100).

3. The lower side door of the open wagon as described in claim 2, characterized in that, Along the arrangement direction of the outer side and the inner side, the projection structure of the first thickened layer (110) is a rectangular structure with a length of L2 and a width of H2.

4. The lower side door of the convertible as described in claim 3, characterized in that, The thickening layer also includes a third thickening layer (130) disposed on the side of the first thickening layer (110) facing away from the lower door panel (100). Along the arrangement direction of the outer side and the inner side, the projection structure of the first thickened layer (110) is a rectangular structure with a length of L3 and a width of H2, where L3 < L2 and the third thickened layer (130) is located in the middle of the first thickened layer (110) in the length direction.

5. The lower side door of the open wagon as described in claim 2, characterized in that, The number of the first thickened layers (110) is multiple and they are arranged circumferentially along the first protruding region (101).

6. The lower side door of the open wagon as described in claim 1, characterized in that, The thickened layer includes a second thickened layer (120) disposed in the second protruding region (102); along the arrangement direction of the outer side and the inner side, the projection structure of the second thickened layer (120) is a rectangular structure.

7. The lower side door of the convertible as described in claim 6, characterized in that, Along the arrangement direction of the outer and inner sides, the projected edge of the second thickened layer (120) is located outside the edge of the second protruding region (102).

8. The lower side door of the convertible as described in claim 1, characterized in that, The hinge (200) includes a hinge body (210) connected to the lower side panel (100) and a rib (220) on the side of the hinge body (210) facing away from the lower side panel (100). Wherein, the fold (200) satisfies at least one of the following: The hinge body (210) is a multi-layer composite material layer (211) stacked together. The hinge body (210) has a pin hole end and a fastener end (213) facing away from each other. The pin hole end is bent away from the lower door panel (100) to form a pin hole portion (212). The multiple material layer ends of the pin hole end are arranged sequentially towards the pin hole portion (212) in a direction away from the lower door panel (100). And / or, the fastener end (213) has an auxiliary material layer stacked with the multi-layer composite material layer (211). The cross-section of the hinge (200) is a "T" shaped cross-section, and the hinge body (210) is perpendicular to the rib (220); The fold (200) includes a first composite material layer and a second composite material layer. The second composite material layer has a first portion and a second portion arranged at an angle. The first portion is superimposed on the first composite material layer to form the fold body (210), and the second portion forms the rib (220).

9. The lower side door of the convertible as described in claim 1, characterized in that, Meet at least one of the following: The hinge (200) and the lower door panel (100) are an integral structure, or the hinge (200) and the lower door panel (100) are connected by a connecting structure; The hinge (200) and the lower door panel (100) are made of fiber-reinforced resin-based composite material; The cross-section of the first protruding region (101) is a trapezoidal structure; The thickened layer is made of the same material as the lower door panel (100).

10. A wagon, comprising a body and a lower side door disposed on the body, characterized in that, The lower side door of the open wagon is the lower side door of the open wagon as described in any one of claims 1-9.

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