Folding box

Abstract

The utility model provides a folding box. The folding box comprises a plate spring and an end frame. The plate spring is arranged beside the bottom frame and provided with a free end. The end frame is rotatably connected to the bottom frame through a hinge, the hinge comprises a plate spring pressing plate, and the plate spring pressing plate is closer to the free end of the plate spring than the end frame, so that the plate spring pressing plate can abut against the upper portion of the plate spring while rotating, and therefore the plate spring is bent and deformed. Wherein in the process that the plate spring is pressed down by the plate spring pressing plate, the distance from the surface, making contact with the plate spring, of the plate spring pressing plate to the rotating axis of the hinge tends to be gradually increased. When the end frame begins to rotate, the plate spring pressing plate can abut against the plate spring earlier, so that the plate spring begins to bend and deform, and the plate spring enters a working state in advance. Due to the fact that the distance between the contact surface and the hinge shaft is gradually increased, when the plate spring pressing plate continues to press the plate spring downwards, a large distance is kept between the plate spring pressing plate and the end of the plate spring, and the plate spring pressing plate is prevented from being disengaged from the end face of the plate spring during folding.

Description

Technical Field

[0001] The utility model relates to the technical field of containers, and more specifically to a folding box. Background Art

[0002] For existing folding boxes, in order to reduce the impact during the folding of the end frame and reduce the labor intensity when the end frame is erected, a boosting mechanism is generally provided. This boosting mechanism mainly realizes its function by the leaf spring pressing shaft arranged on the end frame compressing the leaf spring on the chassis.

[0003] Currently, when the end frame is folded, the leaf spring pressing shaft contacts the leaf spring relatively late, and the boosting mechanism starts slowly. When the end frame is erected, the dead travel is too long. The existing leaf spring pressing shafts are generally short cylinders or semi-cylinders and are welded to the bottom of the end frame. Affected by the structure, when the end frame is erected, the distance between the leaf spring pressing shaft and the free end of the leaf spring is large, and the dead travel is too long. To make the leaf spring pressing shaft contact the free end of the leaf spring as soon as possible and enter the working state in advance, the leaf spring pressing shaft needs to be moved down to make it as close to the leaf spring as possible. However, when the distance between the leaf spring pressing shaft and the leaf spring is too close, the leaf spring pressing shaft will protrude from the end face of the leaf spring after the end frame is folded, resulting in jamming. To prevent the leaf spring pressing shaft from protruding from the end face of the leaf spring during folding, the leaf spring pressing shaft needs to be moved up, which will lead to the leaf spring pressing shaft being too far from the leaf spring when the end frame is erected, and the dead travel is too long.

[0004] In addition, for the existing leaf spring pressing shaft structure, the torque generated by the self-weight of the end frame is always greater than the supporting torque provided by the leaf spring. As a result, when the end frame is folded, the buffering provided by the leaf spring is small, and the end frame falls down too fast and is likely to hit the chassis and workers, posing a safety hazard; when lifting the end frame, the boosting provided by the leaf spring is insufficient, the working stroke is short, and the labor intensity is large.

[0005] Therefore, a folding box is needed to at least partially solve the above problems. Summary of the Utility Model

[0006] A series of simplified concepts are introduced in the Summary of the Utility Model section, which will be further detailed in the Detailed Description section. The Summary of the Utility Model section of the present utility model does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0007] To at least partially solve the above problems, the present utility model provides a folding box with a chassis, including:

[0008] A leaf spring, the leaf spring is arranged beside the chassis, and the leaf spring has a free end;

[0009] An end frame, the end frame is rotatably connected to the chassis through a hinge, the hinge includes a leaf spring pressing plate, the leaf spring pressing plate is closer to the free end of the leaf spring than the end frame, so that the leaf spring pressing plate can be pressed against the upper side of the leaf spring while rotating, so that the leaf spring is bent and deformed; wherein,

[0010] During the process of the leaf spring pressing plate pressing down the leaf spring, the distance from the surface of the leaf spring pressing plate in contact with the leaf spring to the rotation axis of the hinge shows a gradually increasing trend.

[0011] For the folding box according to the present invention, when the end frame starts to rotate, the leaf spring pressing plate can press against the leaf spring earlier, causing the leaf spring to start bending and deforming, so as to enter the working state in advance, improving the sensitivity and efficiency of the folding box operation. Since the distance from the contact surface to the hinge axis is increasing, when the leaf spring pressing plate continues to press down the leaf spring, a relatively large distance is maintained from the end of the leaf spring, ensuring that the leaf spring pressing plate always maintains stable contact with the leaf spring during rotation, and preventing the leaf spring pressing plate from disengaging from the end face of the leaf spring during folding.

[0012] Optionally, a guiding curved surface is provided on the outer periphery of the side of the leaf spring pressing plate close to the leaf spring, the guiding curved surface can connect and act on the leaf spring, and the distances from different positions of the guiding curved surface along the circumferential direction of the leaf spring pressing plate to the rotation axis of the hinge are different.

[0013] Optionally, the guiding curved surface includes a first curved surface, a transition curved surface and a second curved surface connected in sequence, and the first curved surface is closer to the free end of the leaf spring than the transition curved surface; wherein,

[0014] The radius of curvature of the transition curved surface is greater than the radius of curvature of the first curved surface;

[0015] The radius of curvature of the transition curved surface is greater than the radius of curvature of the second curved surface.

[0016] Optionally, the transition curved surface is a straight line segment.

[0017] Optionally, the guiding curved surface includes a first curved surface, a transition curved surface and a second curved surface connected in sequence, and the first curved surface is closer to the free end of the leaf spring than the transition curved surface; wherein,

[0018] The radius of curvature of the first curved surface is greater than the radius of curvature of the transition curved surface;

[0019] The radius of curvature of the first curved surface is greater than the radius of curvature of the second curved surface.

[0020] Optionally, the guiding curved surface includes a first curved surface, a transition curved surface and a second curved surface connected in sequence, and the first curved surface is closer to the free end of the leaf spring than the transition curved surface; wherein,

[0021] The radius of curvature of the second surface is greater than that of the first surface;

[0022] The radius of curvature of the second surface is greater than that of the transition surface.

[0023] Optionally, the guiding surface includes a first surface, a transition surface, and a second surface that are connected in sequence. The first surface is closer to the free end of the leaf spring than the transition surface; wherein,

[0024] The radius of curvature of any two of the first surface, the transition surface, and the second surface is equal and greater than that of the third.

[0025] Optionally, the guiding surface includes a first surface and a second surface. The first surface is closer to the free end of the leaf spring than the second surface, and one or more notches are provided between the first surface and the second surface; wherein,

[0026] Both the first surface and the second surface are convex surfaces, and the notch is a plane or a surface that is concave inward and does not contact the leaf spring.

[0027] Optionally, in the state where the end frame is erected, at least a part of the guiding surface extends along the height direction of the folding box.

[0028] Optionally, the hinge further includes a hinge plate connected to the leaf spring pressing plate, and reinforcing ribs are provided between the hinge plate and the leaf spring pressing plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The following drawings of the embodiments of the present invention are here as a part of the present invention for understanding the present invention. The embodiments and descriptions of the present invention are shown in the drawings to explain the principles of the present invention. In the drawings,

[0030] Figure 1 is a three-dimensional schematic diagram of a folding box according to a preferred embodiment of the present invention, in which the end frame is in an erected state;

[0031] Figure 2 is a three-dimensional schematic diagram of a folding box according to a preferred embodiment of the present invention, in which the end frame is in a folded state;

[0032] Figure 3 is Figure 1 a partial enlarged view of part A in

[0033] Figure 4 is Figure 2 a partial enlarged view of part B in

[0034] Figure 5Schematic three-dimensional structure diagram of the hinge plate and the leaf spring pressing plate in Embodiment 1;

[0035] Figure 6 Schematic front view of the hinge plate and the leaf spring pressing plate in Embodiment 1;

[0036] Figure 7 Diagram showing the change in the contact state between the free end of the leaf spring and the leaf spring pressing plate during the folding process of the end frame;

[0037] Figure 8 Partial three-dimensional schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 2;

[0038] Figure 9 Partial front view schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 2;

[0039] Figure 10 Partial three-dimensional schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 3;

[0040] Figure 11 Partial front view schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 3;

[0041] Figure 12 Partial three-dimensional schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 4;

[0042] Figure 13 Partial front view schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 4;

[0043] Figure 14 Partial three-dimensional schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 5;

[0044] Figure 15 Partial front view schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 5;

[0045] Figure 16 Partial three-dimensional schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 6;

[0046] Figure 17 Partial front view schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 6;

[0047] Figure 18 Partial three-dimensional schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 7;

[0048] Figure 19 Partial front view schematic diagram of the leaf spring pressing plate and the leaf spring in Embodiment 7;

[0049] Figure 20 Partial front view schematic diagram of the leaf spring pressing plate in Embodiment 7.

[0050] Explanation of Reference Numerals

[0051] 1: Underframe

[0052] 2: End frame

[0053] 3: Hinge

[0054] 31: Hinge shaft

[0055] 32: Hinge plate

[0056] 321: Connection hole

[0057] 33: Leaf spring pressure plate

[0058] 331: First curved surface

[0059] 332: Transition curved surface

[0060] 333: Second curved surface

[0061] 334: Notch

[0062] 4: Leaf spring

[0063] 41: Free end of leaf spring

[0064] 42: Fixed end of leaf spring

[0065] DH: Height direction Detailed implementation mode

[0066] In the following description, a large number of specific details are given to provide a more thorough understanding of the present utility model. However, it is obvious to those skilled in the art that the embodiments of the present utility model can be implemented without one or more of these details. In other examples, in order to avoid confusion with the embodiments of the present utility model, some technical features well known in the art are not described.

[0067] In this article, ordinal numbers such as "first" and "second" cited in the present utility model are only identifiers and do not have any other meanings, such as a specific order, etc. Moreover, for example, the term "first component" itself does not imply the existence of a "second component", and the term "second component" itself does not imply the existence of a "first component".

[0068] In this article, "up", "down", "front", "rear", "left", "right", etc. are only used to represent the relative positional relationship between relevant parts, rather than defining the absolute positions of these relevant parts.

[0069] In this article, "equal", "same", etc. are not strict mathematical and / or geometric restrictions, and also include errors that can be understood by those skilled in the art and are allowed in manufacturing or using, etc.

[0070] Unless otherwise specified, the numerical ranges in this document include not only the entire range between its two endpoints, but also several sub-ranges contained therein.

[0071] Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the present invention is thorough and complete, and the concept of these exemplary embodiments is fully conveyed to those of ordinary skill in the art.

[0072] As Figure 1 and Figure 2 shown, the present invention provides a folding box, which is composed of a bottom frame 1 and end frames 2. The end frames 2 are hinged to both ends of the bottom frame 1 through hinges 3.

[0073] As Figures 3 to 6 shown, the hinge 3 includes a hinge plate 32 and a leaf spring pressing plate 33 connected to each other. The hinge plate 32 is provided with a connection hole 321, and a hinge shaft 31 is rotatably connected in the connection hole 321. The hinge 3 is connected to the bottom frame 1 through the hinge shaft 31.

[0074] The lower end of the end frame 2 is fixedly connected to the hinge plate 32, enabling it to rotate around the hinge shaft 31, thereby switching between the erected state and the folded state of the end frame 2. On both sides of the bottom frame 1 near the hinge 3, leaf springs 4 are provided. The leaf spring 4 includes a leaf spring free end 41 and a leaf spring fixed end 42 arranged in opposite directions along its length direction. The leaf spring fixed end 42 is the end far from the hinge 3 and is fixed on the bottom frame 1; the leaf spring free end 41 is the end close to the hinge 3 and can deform under force to generate elastic force. By providing the leaf springs 4 on both sides of the bottom frame 1 and providing a leaf spring pressing plate 33 on the end frame 2 that interacts with the leaf springs 4, stable support and assistance can be provided during the folding and erection of the end frame 2. When the end frame 2 is erected, the leaf spring pressing plate 33 presses against the leaf spring 4, and the leaf spring 4 generates elastic force to help the end frame 2 stand up; when the end frame 2 is folded, the elastic force of the leaf spring 4 plays a buffering role, slowing down the folding speed of the end frame 2 and avoiding damage caused by falling too quickly.

[0075] As Figure 5 shown, the leaf spring pressing plate 33 is fixed on the side of the hinge plate 32 close to the leaf spring 4 and can rotate around the hinge shaft 31 as the hinge plate 32 rotates. The leaf spring pressing plate 33 is closer to the free end of the leaf spring 4 than the end frame 2, so that the leaf spring pressing plate 33 can press above the leaf spring 4 while rotating, thereby causing the leaf spring 4 to bend and deform. When the end frame 2 starts to rotate, the leaf spring pressing plate 33 can press against the leaf spring 4 earlier, causing the leaf spring 4 to start bending and deforming, so as to enter the working state earlier and improve the sensitivity and efficiency of the folding box operation.

[0076] Optionally, a guiding surface is provided on the outer periphery of the side of the leaf spring pressing plate 33 close to the leaf spring 4. During the process of the leaf spring pressing plate 33 pressing down the leaf spring 4, as the end frame 2 rotates, the compression amount of the free end of the leaf spring 4 increases, and the distance from the free end of the leaf spring 4 to the hinge shaft 31 first decreases and then increases. Therefore, in order to prevent the leaf spring pressing plate 33 from disengaging from the end face of the leaf spring 4, the distances from the points on the guiding surface of the leaf spring pressing plate 33 to the hinge shaft are increasing, so that when the leaf spring pressing plate 33 continues to press down the leaf spring 4, it always maintains a large distance from the end of the leaf spring 4, ensuring that the leaf spring pressing plate 33 always maintains stable contact with the leaf spring 4 during rotation, avoiding the leaf spring pressing plate 33 from disengaging from the end face of the leaf spring 4 during folding, and enhancing the stability and safety of the folding box.

[0077] The guiding surface of the leaf spring pressing plate 33 can connect to and act on the leaf spring 4, and the distances from different positions of the guiding surface along the circumferential direction of the leaf spring pressing plate 33 to the rotation axis of the hinge 3 are different. The design of the guiding surface enables the leaf spring pressing plate 33 to contact and act on the leaf spring 4 more smoothly during rotation, realizing a guiding function.

[0078] The guiding surface of the leaf spring pressing plate 33 is mainly composed of three arc surfaces, and the transition between each arc surface is smooth. The guiding surface includes a first surface 331, a transition surface 332, and a second surface 333 that are connected in sequence. The first surface 331 is closer to the free end of the leaf spring 4 than the transition surface 332. The distances from the points on the arcs of the first surface 331, the transition surface 332, and the second surface 333 to the axis of the hinge shaft 31 show a gradually increasing trend.

[0079] As Figure 7 (a) shows, when the end frame 2 starts to fold from the erected state, since the end frame 2 cannot flip by its own weight in the erected state, it needs to be flipped around the hinge shaft 31 under the action of an artificial torque. There is a certain gap between the first surface 331 of the leaf spring pressing plate 33 and the free end 41 of the leaf spring. At this time, the leaf spring 4 is not compressed and does not provide assistance, which can reduce the labor intensity of manual flipping.

[0080] As Figure 7 (b) shows, as the end frame 2 gradually folds, the end frame 2 flips under the torque formed by its own weight. The first surface 331 of the leaf spring pressing plate 33 contacts the free end 41 of the leaf spring, and the leaf spring 4 starts to be compressed quickly. The supporting torque provided by the leaf spring 4 cancels out most of the torque generated by the weight of the end frame 2, playing a buffering role and reducing the folding speed of the end frame 2.

[0081] As Figure 7As shown in (c), when the end frame 2 folds into the middle section, the torque generated by the self-weight of the end frame 2 becomes larger and larger. At this time, the transition surface 332 of the leaf spring pressure plate 33 comes into contact with the free end 41 of the leaf spring. Since the distances (i.e., the force arms) from the contact points on the arc of the transition surface 332 to the axis of the hinge shaft 31 are larger than those of the contact points on the first surface 331, the compression amount of the free end 41 of the leaf spring is also larger. Therefore, both the elastic force and the force arm of the leaf spring 4 increase, so the supporting torque provided by the leaf spring 4 also becomes larger and larger until it reaches a basically stable state with the torque generated by the self-weight of the end frame 2, further reducing the folding speed of the end frame 2 and realizing the smooth folding of the end frame 2.

[0082] As shown in Figure 7 (d), as the end frame 2 further folds, the second surface 333 of the leaf spring pressure plate 33 comes into contact with the free end 41 of the leaf spring. The distances (i.e., the force arms) from the contact points on the second surface 333 to the axis of the hinge shaft 31 continue to increase, the elastic force generated by the compression of the leaf spring 4 and the force arm also continue to increase, and the supporting torque provided by the leaf spring 4 will be greater than the torque generated by the self-weight of the end frame 2, avoiding the end frame 2 from falling too fast when folding and hitting the chassis 1 or the staff, which is safer and more reliable. At this time, if a little downward pressure is applied manually, the folding action of the end frame 2 can be realized.

[0083] The process of the end frame 2 switching from the folded state to the erected state is opposite to the above process. The setting of the leaf spring pressure plate 33 can make the leaf spring 4 play a better boosting role and reduce the labor intensity of the worker when lifting the end frame 2.

[0084] In addition, since the first surface 331 and the second surface 333 of the leaf spring pressure plate 33 are spaced apart by a certain distance along the height direction DH of the hinge plate 32, the first surface 331 can be as close as possible to the free end 41 of the leaf spring when the end frame 2 is erected, so as to provide buffering earlier and disengage from the boost later; at this time, the second surface 333 can still maintain a large distance from the axis of the hinge shaft, so that the second surface 333 will not come out of the free end 41 of the leaf spring when the end frame 2 folds, enhancing the stability and safety of the folding box. Through the setting of the first surface 331 and the second surface 333, the leaf spring pressure plate 33 has a certain size. Therefore, the working stroke of the leaf spring pressure plate 33 acting on the leaf spring 4 is increased, and the buffering and boosting effects are better.

[0085] Optionally, a reinforcing rib is provided between the hinge plate 32 and the leaf spring pressure plate 33. The connection strength between the hinge plate 32 and the leaf spring pressure plate 33 is enhanced.

[0086] The guiding surface of the leaf spring pressure plate 33 is introduced below through specific embodiments.

[0087] Embodiment 1

[0088] As shown in Figures 3 to 6As shown, the guiding surface includes a first surface 331, a transition surface 332, and a second surface 333 that are connected in sequence. The first surface 331 is closer to the free end of the leaf spring 4 than the transition surface 332.

[0089] The radius of curvature r2 of the transition surface 332 is greater than the radius of curvature r1 of the first surface 331. The radius of curvature r2 of the transition surface 332 is greater than the radius of curvature r3 of the second surface 333.

[0090] Optionally, the radius of curvature r3 of the second surface 333 is greater than, less than, or equal to the radius of curvature r1 of the first surface 331. Here, the size relationship between the radius of curvature r3 of the second surface 333 and the radius of curvature r1 of the first surface 331 is not specifically limited.

[0091] Optionally, the radius of curvature r1 of the first surface 331 is relatively small, which is convenient for manual force application.

[0092] Optionally, the hinge plate 32 and the leaf spring pressing plate 33 are integrally formed.

[0093] Embodiment 2

[0094] As Figure 8 and Figure 9 shown, the difference between this embodiment and Embodiment 1 is that the leaf spring pressing plate 33 is a sheet metal bending part. The settings of the first surface 331 and the second surface 333 are similar to those in Embodiment 1.

[0095] Optionally, the transition surface 332 is a section of a plane.

[0096] The transition surface 332 is a straight line segment. The radius of curvature of the straight line segment is relatively large to avoid cracks or deformations at the bending point.

[0097] Embodiment 3

[0098] As Figure 10 and Figure 11 shown, the difference between this embodiment and Embodiment 1 is that the leaf spring pressing plate 33 is a casting.

[0099] The radius of curvature r2 of the transition surface 332 is greater than the radius of curvature r1 of the first surface 331. The radius of curvature r2 of the transition surface 332 is equal to the radius of curvature r3 of the second surface 333.

[0100] Optionally, the transition surface 332 and the second surface 333 are the same arc surface, that is, the working surface of the leaf spring pressing plate 33 consists of only 2 arc surfaces. This makes the design and manufacturing process of the transition surface 332 easier, not only reducing the manufacturing cost but also improving the production efficiency.

[0101] Similarly, optionally, the transition surface 332 and the first surface 331 are the same arc surface, that is, the working surface of the leaf spring pressing plate 33 consists of only 2 arc surfaces.

[0102] Example 4

[0103] As Figure 12 and Figure 13 shown, the guiding surface includes a first surface 331, a transition surface 332 and a second surface 333 which are connected in sequence. The first surface 331 is closer to the free end of the leaf spring 4 than the transition surface 332.

[0104] The radius of curvature of the first surface 331 is greater than that of the transition surface 332. The radius of curvature of the first surface 331 is greater than that of the second surface 333. The relatively large radius of curvature of the first surface 331 increases the downward pressing stroke of the free end 41 of the leaf spring.

[0105] Example 5

[0106] As Figure 14 and Figure 15 shown, the guiding surface includes a first surface 331, a transition surface 332 and a second surface 333 which are connected in sequence. The first surface 331 is closer to the free end of the leaf spring 4 than the transition surface 332.

[0107] The radius of curvature of the second surface 333 is greater than that of the first surface 331. The radius of curvature of the second surface 333 is greater than that of the transition surface 332. The relatively large radius of curvature of the second surface 333 ensures that the leaf spring pressing plate 33 does not come out of the free end 41 of the leaf spring.

[0108] Example 6

[0109] As Figure 16 and Figure 17 shown, the guiding surface includes a first surface 331, a transition surface 332 and a second surface 333 which are connected in sequence. The first surface 331 is closer to the free end of the leaf spring 4 than the transition surface 332.

[0110] The radius of curvature of the first surface 331 is equal to that of the second surface 333 and greater than that of the transition surface 332.

[0111] Example 7

[0112] As Figure 18 and Figure 19 shown, the guiding surface includes a first surface 331 and a second surface 333. The first surface 331 is closer to the free end of the leaf spring 4 than the second surface 333. A notch 334 is further provided between the first surface 331 and the second surface 333.

[0113] Preferably, both the first surface 331 and the second surface 333 are convex surfaces, and the notch 334 is a plane or a surface that is concave inward and does not contact the leaf spring.

[0114] Reference Figure 20 , in some embodiments of the present embodiment, as Figure 20 (a) shows, the notch 334 is a curved surface recessed inward. As Figure 20 (b) shows, the notch 334 is a plane recessed inward. As Figure 20 (c) shows, the notch 334 is provided in multiple numbers, and there is a convex curved surface or plane between the notches 334. In the present embodiment, the curved surface or plane between the notches 334 is not specifically limited.

[0115] Preferably, in actual production, the first curved surface 331 and the second curved surface 333 can be cut with a flat plate or welded together with two round steel bars.

[0116] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. Terms such as "provided" that appear herein can either mean that one component is directly attached to another component or that one component is attached to another component through an intermediate component. The features described in one embodiment herein can be applied alone or in combination with other features to another embodiment, unless the feature is not applicable or otherwise stated in that other embodiment.

[0117] The present invention has been described through the above embodiments, but it should be understood that the above embodiments are only for the purpose of illustration and example, and are not intended to limit the present invention within the scope of the described embodiments. Those skilled in the art can understand that according to the teachings of the present invention, more variations and modifications can be made, and these variations and modifications all fall within the scope of protection required by the present invention.

Claims

1. A folding box having a chassis, characterized in that, Comprising: A leaf spring, which is arranged beside the chassis, and the leaf spring has a free end; An end frame, which is rotatably connected to the chassis through a hinge. The hinge includes a leaf spring pressing plate, and the leaf spring pressing plate is closer to the free end of the leaf spring than the end frame, so that the leaf spring pressing plate can be pressed against the upper side of the leaf spring while rotating, thereby causing the leaf spring to bend and deform; wherein, During the process of the leaf spring pressing plate pressing down the leaf spring, the distance from the surface of the leaf spring pressing plate in contact with the leaf spring to the rotation axis of the hinge shows a gradually increasing trend.

2. The folding box according to claim 1, wherein, A guiding curved surface is provided on the outer periphery of the side of the leaf spring pressing plate close to the leaf spring. The guiding curved surface can connect and act on the leaf spring, and the distances from different positions of the guiding curved surface along the circumferential direction of the leaf spring pressing plate to the rotation axis of the hinge are different.

3. The folding box according to claim 2, wherein The guiding curved surface includes a first curved surface, a transition curved surface and a second curved surface connected in sequence. The first curved surface is closer to the free end of the leaf spring than the transition curved surface; wherein, The radius of curvature of the transition curved surface is greater than the radius of curvature of the first curved surface; The radius of curvature of the transition curved surface is greater than the radius of curvature of the second curved surface.

4. The folding box according to claim 3, characterized in that, The transition curved surface is a straight line segment.

5. The folding box according to claim 2, characterized in that, The guiding curved surface includes a first curved surface, a transition curved surface and a second curved surface connected in sequence. The first curved surface is closer to the free end of the leaf spring than the transition curved surface; wherein, The radius of curvature of the first curved surface is greater than the radius of curvature of the transition curved surface; The radius of curvature of the first curved surface is greater than the radius of curvature of the second curved surface.

6. The folding box according to claim 2, characterized in that, The guiding curved surface includes a first curved surface, a transition curved surface and a second curved surface connected in sequence. The first curved surface is closer to the free end of the leaf spring than the transition curved surface; wherein, The radius of curvature of the second curved surface is greater than the radius of curvature of the first curved surface; The radius of curvature of the second curved surface is greater than the radius of curvature of the transition curved surface.

7. The folding box according to claim 2, wherein The guiding curved surface includes a first curved surface, a transition curved surface and a second curved surface connected in sequence. The first curved surface is closer to the free end of the leaf spring than the transition curved surface; wherein, The radius of curvature of any two of the first curved surface, the transition curved surface and the second curved surface is equal and greater than the radius of curvature of the third one.

8. The folding box according to claim 2, characterized in that, The guiding curved surface includes a first curved surface and a second curved surface. The first curved surface is closer to the free end of the leaf spring than the second curved surface. One or more notches are arranged between the first curved surface and the second curved surface; wherein, Both the first curved surface and the second curved surface are outwardly convex curved surfaces, and the notches are inwardly concave planes or curved surfaces that do not contact the leaf spring.

9. The folding box according to any one of claims 2 to 8, characterized in that, In the state where the end frame is erected, at least part of the guiding curved surface extends along the height direction of the folding box.

10. The folding box according to any one of claims 1 to 8, characterized in that, The hinge further includes a hinge plate connected to the leaf spring pressing plate, and a reinforcing rib is arranged between the hinge plate and the leaf spring pressing plate.

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