Backrest folding structure and wheelchair

Abstract

The utility model discloses a backrest folding structure, which comprises a bracket, the two brackets are rotationally connected through the rotary connecting structure; the clamping structure comprises a clamping piece; the angle adjusting structure comprises an adjusting part; when the two supports rotate to the unfolding state in the opposite forward direction, the extending ends of the adjusting pieces abut against the corresponding supports, and the extending ends of the clamping pieces abut against the corresponding supports so as to limit relative rotation of the two supports. The clamping pieces are driven to be away from the corresponding supports so as to relieve rotation limitation, and the two supports reversely rotate to be in the folded state. According to the backrest folding structure, double limiting is achieved through the adjusting piece and the clamping piece, the structure is compact, stability is high, one support can rotate relative to the other support and can be folded, and the backrest folding structure is easy to use and particularly suitable for wheelchairs. The wheelchair adopts the backrest folding structure, and is compact in overall structure, high in stability and easy to use.

Description

Technical Field

[0001] This utility model relates to the field of wheelchair technology, and in particular to a backrest folding structure and a wheelchair. Background Technology

[0002] Wheelchairs are a type of mobile seating commonly used by people with limb disabilities and mobility impairments. For wheelchairs with backrests, the backrest can be fixed or movable relative to the seating area. A fixed backrest cannot be angled, while a movable backrest allows for angle adjustment. In related technologies, the backrest can also rotate from an unfolded state to a folded state relative to the seating area, making foldable wheelchairs more portable. A toothed structure is often used in these technologies to achieve backrest angle adjustment. However, this method is space-consuming and inconvenient to use. Furthermore, after the backrest angle is adjusted, a single structural limiter is typically used, resulting in poor stability. Utility Model Content

[0003] The purpose of this utility model is to disclose a backrest folding structure that uses adjusting parts and snap-fit ​​parts to achieve double limiting. The structure is compact and has strong stability. One support can rotate and fold relative to the other support. It is easy to use and is especially suitable for wheelchairs.

[0004] The second objective of this utility model is to disclose a wheelchair that adopts the backrest folding structure, which has a compact overall structure, strong stability, and is easy to use.

[0005] To achieve the first objective mentioned above, this utility model discloses a backrest folding structure, comprising:

[0006] support;

[0007] A rotating connection structure is used to rotatably connect two supports.

[0008] The snap-fit ​​structure includes a snap-fit ​​member, the connecting end of which is movably connected to one of the brackets, the protruding end of which abuts against another bracket or a rotating connection structure to restrict the relative rotation of the two brackets, and the protruding end of which separates from the other bracket or the rotating connection structure to release the rotation restriction.

[0009] An angle adjustment structure includes an adjustment member, the connecting end of which is movably connected to one of the supports, and the extending end of which abuts against the other support to limit the relative rotation angle between the two supports.

[0010] As an optional implementation, the snap-fit ​​structure also includes a slide rail and an elastic element. The slide rail is connected and fixed to one of the brackets. The snap-fit ​​element and the elastic element are both inserted into the slide rail and are slidably connected to the slide rail. The snap-fit ​​element and the elastic element are coaxially arranged. The elastic element drives the snap-fit ​​element to abut against or rotate with the other bracket to restrict the relative rotation of the two brackets.

[0011] As an optional implementation, the snap-fit ​​structure also includes an operating member that is drive-connected to the snap-fit ​​member. The operating member drives the snap-fit ​​member away from another bracket or rotatable connection structure to release the rotation restriction.

[0012] As an optional implementation, both sides of the two brackets are provided with snap-fit ​​structures, the operating parts of the two snap-fit ​​structures are connected as one piece, and the operating parts are rope structures.

[0013] As an optional implementation, the rotating connection structure includes a rotating shaft and a connecting piece. The connecting piece is disposed between two supports. One end of the connecting piece is fixedly connected to one of the supports, and the other end of the connecting piece is rotatably connected to the other support via the rotating shaft.

[0014] As an optional implementation, the connecting end of the adjusting member is threadedly connected to one of the brackets;

[0015] The connecting piece is provided with at least two third limiting holes for abutting against the snap-fit ​​component, and the position of the third limiting holes is adapted to the adjustment position of the adjusting component;

[0016] When the snap-fit ​​part abuts against one of the third limiting holes, the protruding end of the adjusting part abuts against the other bracket.

[0017] As an alternative implementation, one of the supports is a main support, and the other support is a backrest support.

[0018] As an optional implementation, the connecting end of the snap-fit ​​is movably connected to the main body bracket, the protruding end of the snap-fit ​​abuts against the backrest bracket or the rotating connection structure to restrict the relative rotation between the main body bracket and the backrest bracket, and the protruding end of the snap-fit ​​is separated from the backrest bracket or the rotating connection structure to release the rotation restriction.

[0019] As an optional implementation, the connecting end of the adjusting member is threadedly connected to the backrest bracket, and the protruding end of the adjusting member abuts against the main body bracket to limit the relative rotation angle between the main body bracket and the backrest bracket.

[0020] When the main support and the backrest support are rotated to the unfolded state in a relatively forward direction, the extended end of the adjusting component abuts against the main support.

[0021] To achieve the second objective mentioned above, this utility model discloses a wheelchair, including the aforementioned backrest folding structure.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] 1. The backrest folding structure in this utility model uses an adjusting component to limit the relative rotation angle of the two supports, and further uses a snap-fit ​​component to limit the relative rotation of the two supports. Thus, the adjusting component and the snap-fit ​​component achieve double limiting. The structure is compact and has strong stability. One support can rotate and fold relative to the other support. It is easy to use and is especially suitable for wheelchairs.

[0024] 2. The wheelchair in this utility model adopts the backrest folding structure, which has a compact overall structure, strong stability, and is easy to use. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments 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.

[0026] Figure 1 This is a first-view external structural schematic diagram of the backrest folding structure in the folded state of Embodiment 1 of this utility model;

[0027] Figure 2 This is a second-view external structural schematic diagram of the backrest folding structure in the folded state of Embodiment 1 of this utility model;

[0028] Figure 3 This is a third-view external structural schematic diagram of the backrest folding structure in the folded state of Embodiment 1 of this utility model;

[0029] Figure 4 This is Embodiment 1 of the present utility model. Figure 3 Schematic diagram of the cross-sectional structure along the AA direction;

[0030] Figure 5 This is Embodiment 1 of the present utility model. Figure 4 A partial schematic diagram;

[0031] Figure 6 This is an exploded view of the backrest folding structure of Embodiment 1 of this utility model;

[0032] Figure 7 A schematic diagram of the external structure of the backrest folding structure in the unfolded state in Embodiment 1 of this utility model.

[0033] Explanation of key figure labels:

[0034] 10. Bracket; 20. Rotary connection structure; 201. Rotating shaft; 202. Connecting piece; 203. Third limiting hole; 30. Snap-fit ​​structure; 301. Snap-fit ​​part; 302. Slide rail; 303. Elastic part; 304. Operating part; 305. First limiting hole; 306. Second limiting hole; 40. Angle adjustment structure; 401. Adjusting part; 402. Tightening nut. Detailed Implementation

[0035] 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.

[0036] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this invention and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0037] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0038] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this utility model based on the specific circumstances.

[0039] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0040] The technical solution of this utility model will be further described below with reference to the embodiments and accompanying drawings.

[0041] Example 1

[0042] Please see Figures 1-7 This application discloses a backrest folding structure, including: a support 10; a rotatable connection structure 20, through which two supports 10 are rotatably connected; a snap-fit ​​structure 30, which includes a snap-fit ​​member 301, the connecting end of the snap-fit ​​member 301 being movably connected to one of the supports 10, the protruding end of the snap-fit ​​member 301 abutting against the other support 10 or the rotatable connection structure 20 to restrict the relative rotation of the two supports 10, and the protruding end of the snap-fit ​​member 301 separating from the other support 10 or the rotatable connection structure 20 to release the rotation restriction; and an angle adjustment structure 40, which includes an adjustment member 401, the connecting end of the adjustment member 401 being movably connected to one of the supports 10, and the protruding end of the adjustment member 401 abutting against the other support 10 to restrict the relative rotation angle of the two supports 10.

[0043] When the two supports 10 are rotated to the unfolded state in a relatively forward direction, the protruding end of the adjusting member 401 abuts against the corresponding support 10, and the protruding end of the locking member 301 abuts against the corresponding support 10 or the rotating connection structure 20 to restrict the relative rotation of the two supports 10; by moving the locking member 301 away from the corresponding support 10 or the rotating connection structure 20 to release the rotation restriction, the two supports 10 rotate in the opposite direction to the folded state.

[0044] It should be noted that the above-mentioned forward rotation is clockwise rotation and reverse rotation is counterclockwise rotation; or the above-mentioned forward rotation is counterclockwise rotation and reverse rotation is clockwise rotation.

[0045] The backrest folding structure of this utility model uses an adjusting member 401 to limit the relative rotation angle of the two supports 10, and further uses a snap-fit ​​member 301 to limit the relative rotation of the two supports 10. Thus, the adjusting member 401 and the snap-fit ​​member 301 achieve double limiting. The structure is compact and has strong stability. One support 10 can rotate and fold relative to the other support 10. It is easy to use and is especially suitable for wheelchairs.

[0046] It should be noted that the two supports 10 are the first support and the second support, respectively. The lower support 10 is the first support, and the upper support 10 is the second support. The first support and the second support are rotatably connected by the rotatable connection structure 20.

[0047] For example, the connecting end of the snap-fit ​​301 is movably connected to the first bracket, and the protruding end of the snap-fit ​​301 abuts against or rotates with the second bracket to restrict the relative rotation between the first bracket and the second bracket. The protruding end of the snap-fit ​​301 separates from the second bracket or the rotating connection structure 20 to release the rotation restriction; or, the connecting end of the snap-fit ​​301 is movably connected to the second bracket, and the protruding end of the snap-fit ​​301 abuts against or rotates with the first bracket to restrict the relative rotation between the first bracket and the second bracket. The protruding end of the snap-fit ​​301 separates from the first bracket or the rotating connection structure 20 to release the rotation restriction.

[0048] For example, the connecting end of the adjusting member 401 is movably connected to the first bracket, and the protruding end of the adjusting member 401 abuts against the second bracket to limit the relative rotation angle between the first bracket and the second bracket; or, the connecting end of the adjusting member 401 is movably connected to the second bracket, and the protruding end of the adjusting member 401 abuts against the first bracket to limit the relative rotation angle between the first bracket and the second bracket.

[0049] See Figures 1-7 The connecting end of the snap-fit ​​member 301 is movably connected to the first bracket, and the protruding end of the snap-fit ​​member 301 is connected to the rotating connection structure 20 to restrict the relative rotation of the first bracket and the second bracket. The protruding end of the snap-fit ​​member 301 is separated from the rotating connection structure 20 to release the rotation restriction. The connecting end of the adjusting member 401 is movably connected to the second bracket, and the protruding end of the adjusting member 401 abuts against the first bracket to restrict the relative rotation angle of the first bracket and the second bracket.

[0050] It should be noted that the connecting end of the snap-fit ​​301 and one of the brackets 10 can be connected by sliding connection, threaded connection or rolling connection. The following is an example of the connecting end of the snap-fit ​​301 being connected by sliding connection with one of the brackets 10.

[0051] See Figures 4-6 In this embodiment of the utility model, the snap-fit ​​structure 30 further includes a slide rail 302 and an elastic member 303. The slide rail 302 is connected and fixed to one of the brackets 10. The snap-fit ​​member 301 and the elastic member 303 are both inserted into the slide rail 302, and the snap-fit ​​member 301 is slidably connected to the slide rail 302. The snap-fit ​​member 301 and the elastic member 303 are coaxially arranged. The elastic member 303 drives the snap-fit ​​member 301 to abut against the other bracket 10 or the rotating connection structure 20 to restrict the relative rotation of the two brackets 10.

[0052] Thus, the elastic element 303 provides an elastic pushing force to the snap-fit ​​element 301, so that the snap-fit ​​element 301 can abut against the corresponding other bracket 10 or rotating connection structure 20 under the action of the elastic element 303.

[0053] Specifically, the elastic element 303 is a spring or an elastic column.

[0054] In this embodiment of the utility model, the snap-fit ​​structure 30 further includes an operating member 304, which is connected to the snap-fit ​​member 301 in a transmission manner. The operating member 304 drives the snap-fit ​​member 301 away from the other bracket 10 or the rotational connection structure 20 to release the rotation restriction.

[0055] Specifically, the operating element 304 can be a rigid structure or a flexible structure. For example, the operating element 304 can be a pull rod or a pull rope. The user pulls the operating element 304 to cause the locking element 301 to slide away from one of the brackets 10 or the rotating connection structure 20 to release the rotation restriction.

[0056] In this embodiment of the utility model, one end of the slide rail 302 is provided with a first limiting hole 305 to prevent the snap-fit ​​member 301 from falling out, and the other end of the slide rail 302 is provided with a second limiting hole 306 to prevent the elastic member 303 from falling out.

[0057] In this embodiment of the utility model, both sides of the two brackets 10 are provided with snap-fit ​​structures 30, the operating parts 304 of the two snap-fit ​​structures 30 are connected as one piece, and the operating parts 304 are rope structures.

[0058] See Figure 5 For ease of assembly, the snap-fit ​​part 301 and the slide rail 302 are made separately and then connected into one piece by welding, threaded connection and other methods. The snap-fit ​​part 301 has an operating part 304 with a rope structure inside.

[0059] Since both sides of the two brackets 10 are provided with snap-fit ​​structures 30, the snap-fit ​​structures 30 are used to snap the two sides of the two brackets 10 together. Both sides of the two brackets 10 are subjected to the snap-fit ​​action of the snap-fit ​​structures 30, resulting in balanced force and stable connection.

[0060] See Figures 1-7 The slide rail 302 is fixedly connected to the first bracket. The elastic element 303 drives the locking member 301 to abut against the rotating connection structure 20 to restrict the relative rotation of the two brackets 10. The elastic element 303 provides an elastic pushing force to the locking member 301, so that the locking member 301 can abut against the rotating connection structure 20 under the action of the elastic element 303. The operating element 304 drives the locking member 301 away from the rotating connection structure 20 to release the rotation restriction. The user only needs to pull the operating element 304 to simultaneously drive the two locking members 301 away from the rotating connection structure 20 by sliding to release the rotation restriction. When the user releases the operating element 304, the two locking members 301 are respectively driven by the elastic force of the corresponding elastic element 303 to slide back to their original position, making it easy for the user to use.

[0061] In this embodiment of the utility model, the rotating connection structure 20 includes a rotating shaft 201 and a connecting piece 202. The connecting piece 202 is disposed between two supports 10. One end of the connecting piece 202 is fixedly connected to one of the supports 10, and the other end of the connecting piece 202 is rotatably connected to the other support 10 through the rotating shaft 201.

[0062] See Figure 6 One end of the connecting piece 202 is inserted into the second bracket to achieve connection and fixation, and the connecting piece 202 and the second bracket are tightly fitted; the rotating shaft 201 is provided with threads, and the rotating shaft 201 is threadedly connected to the first bracket to achieve connection and fixation of the rotating shaft 201 itself, wherein the other end of the connecting piece 202 is provided with a through hole that is rotatably connected to the rotating shaft 201 to form a rotatable connection with the rotating shaft 201.

[0063] Because of the connecting piece 202, there is a certain range of movement space between the two supports 10, so the unfolding angle between the two supports 10 can be adjusted by adjusting the adjusting piece 401, thus avoiding interference between the two supports 10.

[0064] It should be noted that the connecting end of the adjusting component 401 and one of the brackets 10 can be connected by sliding connection, threaded connection or rolling connection. The following example illustrates the connection between the connecting end of the adjusting component 401 and one of the brackets 10 by thread.

[0065] In this embodiment of the utility model, the connecting end of the adjusting member 401 is threadedly connected to one of the brackets 10; the connecting piece 202 is provided with at least two third limiting holes 203 for abutting against the snap-fit ​​member 301, and the position arrangement of the third limiting holes 203 is adapted to the adjustment position of the adjusting member 401; when the snap-fit ​​member 301 abuts against one of the third limiting holes 203, the protruding end of the adjusting member 401 abuts against the other bracket 10; this arrangement is applicable to the technical solution where the protruding end of the snap-fit ​​member 301 abuts against the rotating connection structure 20.

[0066] See Figures 1-7 The connecting end of the adjusting member 401 is threadedly connected to the second bracket. When the snap-fit ​​member 301 abuts against one of the third limiting holes 203, the protruding end of the adjusting member 401 abuts against the first bracket.

[0067] Thus, in some other embodiments, the protruding end of the snap-fit ​​member 301 abuts against the corresponding bracket 10, and a third limiting hole 203 for abutting against the snap-fit ​​member 301 is provided on the corresponding bracket 10.

[0068] Since the adjusting member 401 is threadedly connected to the bracket 10, stepless adjustment is achieved between the adjusting member 401 and the bracket 10. That is, by controlling the threaded connection position between the connecting end of the adjusting member 401 and the bracket 10, i.e., by controlling the extension length of the protruding end of the adjusting member 401, the unfolding angle between the two brackets 10 can be adjusted. However, there is a gap between the two third limiting holes 203. In order to achieve the double limiting of the locking member 301 and the adjusting member 401, the cooperation between the locking member 301 and the third limiting hole 203 restricts the adjustment position of the adjusting member 401. Therefore, the angle adjustment between the first bracket and the second bracket is a stepped adjustment.

[0069] In use, the extension length of the extended end of the adjusting member 401 is adjusted by rotating the adjusting member 401 so that when the snap-fit ​​member 301 abuts against one of the third limiting holes 203, the extended end of the adjusting member 401 abuts against the bracket 10, thereby realizing the double limiting of the snap-fit ​​member 301 and the adjusting member 401 and improving the connection stability between the two brackets 10.

[0070] To increase the angle adjustment range between the two brackets 10, the number of third limit holes 203 can be increased.

[0071] Specifically, in order to improve the fit stability between the snap-fit ​​component 301 and the third limiting hole 203, the third limiting hole 203 is a round hole, the protruding end of the snap-fit ​​component 301 is cylindrical, the inner diameter of the third limiting hole 203 is adapted to the outer diameter of the snap-fit ​​component 301, the inner diameter of the third limiting hole 203 is greater than or equal to the outer diameter of the snap-fit ​​component 301, and the unilateral gap range between the inner diameter of the third limiting hole 203 and the outer diameter of the snap-fit ​​component 301 is 0-2mm.

[0072] To prevent the adjusting component 401 from loosening after adjustment, two locking nuts 405 are fitted on the adjusting component 401. By tightening the locking nuts 405, the adjusting component 401 is locked to the corresponding threaded bracket 10.

[0073] In this embodiment of the utility model, see Figure 1 as well as Figure 7 One of the supports 10 is the main support, and the other support 10 is the backrest support.

[0074] Specifically, the first support is the main support, and the second support is the backrest support.

[0075] See Figure 7 In this embodiment of the utility model, the connecting end of the snap-fit ​​member 301 is movably connected to the main support, the protruding end of the snap-fit ​​member 301 abuts against the rotating connection structure 20 to restrict the relative rotation of the main support and the backrest support, and the protruding end of the snap-fit ​​member 301 separates from the rotating connection structure 20 to release the rotation restriction.

[0076] See Figure 7 In this embodiment of the utility model, the connecting end of the adjusting member 401 is threadedly connected to the backrest bracket, and the protruding end of the adjusting member 401 abuts against the main body bracket to limit the relative rotation angle between the main body bracket and the backrest bracket; when the main body bracket and the backrest bracket rotate to the unfolded state by relative forward rotation, the protruding end of the adjusting member 401 abuts against the main body bracket.

[0077] A specific usage process of this utility model is as follows:

[0078] The user pulls the operating element 304 to move the locking element 301 away from the backrest support, thus releasing the rotation restriction. The user rotates the backrest support clockwise relative to the main support to a predetermined angle, at which point it is in an unfolded state, and the protruding end of the adjusting element 401 abuts against the main support. The user releases the operating element 304, and the protruding end of the locking element 301 extends under the action of the elastic element 303 and abuts against the third limiting hole 203 on the connecting piece 202. The locking element 301 and the adjusting element 401 simultaneously restrict the relative rotation between the main support and the backrest support. (See reference...) Figure 7 .

[0079] The user pulls the operating element 304 to move the latching member 301 away from the backrest support, thus releasing the rotation restriction. The user rotates the backrest support counterclockwise relative to the main support to a folded state. The user releases the operating element 304, and the protruding end of the latching member 301 returns to its original position under the action of the elastic member 303. (See reference...) Figures 1-3 .

[0080] Example 2

[0081] To achieve the second objective mentioned above, this utility model discloses a wheelchair, including the aforementioned backrest folding structure.

[0082] The wheelchair in this invention adopts this backrest folding structure, which is compact, stable, and easy to use.

[0083] It should be noted that the wheelchair also includes wheels, a seat cushion, and a backrest cushion. The wheels and seat cushion are connected to the main frame, and the backrest cushion is connected to the backrest frame.

[0084] The foregoing has provided a detailed description of a backrest folding structure and a wheelchair disclosed in the embodiments of this utility model. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the backrest folding structure and wheelchair of this utility model and its core ideas. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A folding structure for a backrest, characterized in that, include: Frame (10); A rotating connection structure (20) is provided, through which the two brackets (10) are rotatably connected; A snap-fit ​​structure (30) includes a snap-fit ​​member (301), the connecting end of which is movably connected to one of the brackets (10), the protruding end of which abuts against the other bracket (10) or the rotating connection structure (20) to restrict the relative rotation of the two brackets (10), and the protruding end of which separates from the other bracket (10) or the rotating connection structure (20) to release the rotation restriction; An angle adjustment structure (40) includes an adjustment member (401), the connecting end of the adjustment member (401) is movably connected to one of the brackets (10), and the protruding end of the adjustment member (401) abuts against the other bracket (10) to limit the relative rotation angle of the two brackets (10).

2. The backrest folding structure according to claim 1, characterized in that: The snap-fit ​​structure (30) further includes a slide rail (302) and an elastic element (303). The slide rail (302) is connected and fixed to one of the brackets (10). The snap-fit ​​element (301) and the elastic element (303) are both inserted into the slide rail (302). The snap-fit ​​element (301) is slidably connected to the slide rail (302). The snap-fit ​​element (301) and the elastic element (303) are coaxially arranged. The elastic element (303) drives the snap-fit ​​element (301) to abut against the other bracket (10) or the rotational connection structure (20) to restrict the relative rotation of the two brackets (10).

3. The backrest folding structure according to claim 2, characterized in that: The snap-fit ​​structure (30) further includes an operating member (304), which is connected to the snap-fit ​​member (301) in a transmission manner. The operating member (304) drives the snap-fit ​​member (301) away from the other bracket (10) or the rotating connection structure (20) to release the rotation restriction.

4. The backrest folding structure according to claim 3, characterized in that: Both sides of the two brackets (10) are provided with the snap-fit ​​structure (30), the operating parts (304) of the two snap-fit ​​structures (30) are connected as one unit, and the operating parts (304) are rope structures.

5. The backrest folding structure according to claim 1, characterized in that: The rotating connection structure (20) includes a rotating shaft (201) and a connecting piece (202). The connecting piece (202) is disposed between two of the brackets (10). One end of the connecting piece (202) is fixedly connected to one of the brackets (10), and the other end of the connecting piece (202) is rotatably connected to the other bracket (10) through the rotating shaft (201).

6. The backrest folding structure according to claim 5, characterized in that: The connecting end of the adjusting member (401) is threadedly connected to one of the brackets (10); The connecting piece (202) is provided with at least two third limiting holes (203) for abutting against the snap-fit ​​member (301), and the position of the third limiting holes (203) is adapted to the adjustment position of the adjusting member (401); When the snap-fit ​​(301) abuts against one of the third limiting holes (203), the protruding end of the adjusting member (401) abuts against the other of the brackets (10).

7. The backrest folding structure according to any one of claims 1-6, characterized in that: One of the brackets (10) is a main support, and the other bracket (10) is a backrest support.

8. The backrest folding structure according to claim 7, characterized in that: The connecting end of the snap-fit ​​member (301) is movably connected to the main body bracket. The protruding end of the snap-fit ​​member (301) abuts against the backrest bracket or the rotating connection structure (20) to restrict the relative rotation between the main body bracket and the backrest bracket. The protruding end of the snap-fit ​​member (301) separates from the backrest bracket or the rotating connection structure (20) to release the rotation restriction.

9. The backrest folding structure according to claim 7, characterized in that: The connecting end of the adjusting member (401) is threadedly connected to the backrest bracket, and the protruding end of the adjusting member (401) abuts against the main body bracket to limit the relative rotation angle between the main body bracket and the backrest bracket. When the main support and the backrest support are rotated to the unfolded state in a relatively forward direction, the protruding end of the adjusting member (401) abuts against the main support.

10. A wheelchair, characterized in that, Includes the backrest folding structure as described in claim 1.

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