Construction method of roof cast-in-place cornice formwork supporting frame

Abstract

The invention discloses a construction method of a roof cast-in-place cornice formwork supporting frame, which comprises at least two wall body fixing pieces for providing mounting support for the formwork supporting frame; the outer protection cantilever frame is used for protecting the exterior of the wall body; and the formwork supporting frame is connected with the wall fixing piece and used for pouring the cornice. By arranging the extension piece on the wall body fixing piece, the formwork supporting frame can act on the wall body fixing piece, then the number of holes punched in the wall body is reduced, damage to a concrete structure is reduced, the stress area of the formwork supporting frame on the wall body can be effectively increased through the wall body fixing piece, and damage to the wall body structure is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of concrete construction, and more specifically to a construction method for a roof cast-in-place cantilevered eaves formwork support frame. Background Art

[0002] In the formwork system of cast-in-place eaves on the roof, there are usually problems such as large width of cast-in-place eaves and high formwork height. When performing formwork, cantilever formwork is required, so the overall strength and stability requirements of the support frame and the protection frame are relatively high. In the existing cantilever formwork system, the steel pipe of the support frame is prone to slippage, bending, deformation and other problems. In order to solve the above problems, it is usually necessary to fix the concrete wall with multi-hole bolts to enhance the formwork requirements. However, in the case where the thickness of the roof eaves is too large (such as the double-layer eaves in this application), the steel pipe scaffolding can no longer meet the frame support requirements, and the overall rigidity of the steel pipe frame is small. It is difficult to meet the overall stability by only relying on fasteners for fixing, and it is easy to slip, instability, etc. Therefore, how to increase the stability of the bracket on the basis of reducing the damage to the concrete structure, meet the requirements of single-sided formwork for ultra-high and ultra-thick walls, and increase the stability of the frame is a technical problem to be solved by the present invention. Summary of the invention

[0003] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention 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 scope of protection of the claimed technical solution.

[0004] To at least partially solve the above problems, the present invention provides a construction method for a cast-in-place roof eaves formwork support frame, comprising: at least two wall fixings to provide installation support for the formwork support frame;

[0005] External protective cantilever frame to protect the outside of the wall;

[0006] The formwork support frame is connected to the wall fixing piece and is used for pouring the cantilevered eaves.

[0007] Preferably, it further comprises at least two wall ties, and when construction is performed at the location of a wall opening, the two wall ties are respectively arranged at the top and bottom of the opening.

[0008] According to the construction method of the cast-in-place roof eaves formwork support frame according to the claim or the description, it is characterized in that it also includes at least one extension piece, the extension piece is connected to the wall fixing piece and extends to the outside of the wall, and the formwork support frame is connected to the extension piece.

[0009] Preferably, the wall fixing part is composed of a bolt, an external wall fastener located at one end of the bolt, an internal wall fastener located at the other end of the bolt, and a gasket assembly, wherein the gasket assembly is located on the outer wall of the wall, one end of the bolt passes through the wall and the gasket assembly and is connected to the external wall fastener, and the other end of the bolt is located on the inner side of the wall and is connected to the internal wall fastener.

[0010] Preferably, the gasket assembly is a first gasket, the first gasket is a pad, the bolt passes through the pad, the external wall fastener consists of two steel pipes, a chevron and a nut, the two steel pipes are respectively located on both sides of the bolt and are fixed to the pad by the chevron and the nut, the chevron and the nut are arranged on the bolt, and the extension piece is connected to one of the steel pipes.

[0011] Preferably, the gasket assembly of the wall fixing member located at the bottom is a second gasket, and the second gasket is composed of a steel pipe sleeve, and the steel pipe sleeve is arranged outside the bolt.

[0012] Preferably, the inner wall fastener is composed of an adjusting member, at least three washers and a nut, the bolt passes through the adjusting member, the washers and the nut, and the adjusting member abuts against the inner wall of the wall through the nut.

[0013] Preferably, the adjusting part is composed of a fitting part abutting against the inner wall of the wall, and a pressing part movably connected to the fitting part, the fitting part is provided with a first through hole, the aperture of the first through hole is larger than the diameter of the bolt, the pressing part is provided with a second through hole, the aperture of the second through hole is adapted to the bolt, one end of the pressing part is a plane abutting against the gasket, and the other end is a convex spherical surface, one end of the fitting part is a plane abutting against the inner wall of the wall, and the other end is a concave ball groove, the diameter of the ball groove is adapted to the diameter of the convex spherical surface of the pressing part.

[0014] Preferably, the formwork support frame consists of a support frame upright connected to the extension piece, a formwork keel located at the top of the support frame upright, and a diagonal rod located between two adjacent support frame uprights, the top of the diagonal rod being connected to the bottom of the formwork keel via a connector, and the bottom of the diagonal rod being connected to the support frame upright.

[0015] Preferably, the connector is composed of a fixing plate provided with a plurality of third through holes, a first connecting plate, a second connecting plate and a third connecting plate provided on the bottom surface of the fixing plate, the first connecting plate and the third connecting plate are provided in parallel, and a gap between the first connecting plate and the third connecting plate constitutes a limiting groove, the first connecting plate is connected to the third connecting plate through the second connecting plate, and the second connecting plate is provided with a through hole communicating with the limiting groove;

[0016] The end of the oblique rod extends into the limiting groove through the through hole and is connected to the bottom surface of the fixing plate;

[0017] Or the end of the oblique rod is connected to the second connecting plate through a rotating assembly.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] By arranging an extension on the wall fixing, the formwork support frame can act on the wall fixing, thereby reducing the number of holes punched in the wall and reducing damage to the concrete structure. The wall fixing can effectively increase the force-bearing area of ​​the formwork support frame on the wall and reduce damage to the wall structure.

[0020] The construction method of the cast-in-place roof eaves formwork support frame described in the present invention, and other advantages, objectives and features of the present invention will be partially reflected through the following description, and will also be partially understood by technical personnel in the field through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 It is a schematic diagram of the construction of the present invention at the hole position.

[0023] Figure 2 It is a schematic diagram of the construction of the present invention at a non-opening location.

[0024] Figure 3 The schematic diagram of the gasket assembly is a first gasket.

[0025] Figure 4 The schematic diagram of the gasket assembly is a second gasket.

[0026] Figure 5 Exploded view of fasteners in wall.

[0027] Figure 6 Schematic diagram of the adjustment member when the bolt is perpendicular to the wall (as shown in A) and inclined to the wall (as shown in B).

[0028] Figure 7 A schematic diagram of the connector structure.

[0029] Figure 8 Schematic diagram of the first connection method between the connector and the diagonal rod.

[0030] Fig. 9 Schematic diagram of the second connection method between the connector and the diagonal rod.

[0031] In the figure: 1 external protective cantilever frame, 2 formwork support frame, 21 support frame upright, 22 formwork keel, 23 diagonal rod, 3 wall connecting member, 4 extension member, 5 bolt, 6 fastener outside the wall, 7 fastener inside the wall, 71 fitting member, 72 pressing member, 81 pad, 82 steel pipe sleeve, 9 connector, 91 fixing plate, 92 first connecting plate, 93 second connecting plate, 94 third connecting plate, 95 limiting groove, 10 rotating assembly, 100 opening, 101 floor, 102 frame beam. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0033] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0034] like Figure 1-Figure 9 As shown, the present invention provides a construction method for a cast-in-place eaves formwork support frame for a roof, comprising: at least two wall fixings, providing installation support for the formwork support frame 2. It should be noted that the two wall fixings described in this embodiment are not just a limitation on the number, and can be understood as the two wall fixings being divided into a lowermost wall fixing (hereinafter referred to as the lowermost fixing), and a wall fixing above the lowermost fixing (hereinafter referred to as the upper fixing). The lowermost fixing is only used to fix the inclined rod of the formwork support frame 2, while the upper fixing plays a role in fixing and supporting the formwork support frame 2, and is the main force point in this application;

[0035] At least one extension member 4, which may be a steel pipe, is connected to the wall fixing member (upper fixing member) and extends to the outside of the wall, and the formwork support frame 2 is connected to the extension member 4 to support and fix the two;

[0036] The wall fixing member is composed of a bolt 5, an external wall fastener 6 located at one end of the bolt 5, an internal wall fastener 7 located at the other end of the bolt 5, and a gasket assembly, wherein the gasket assembly is located on the outer wall of the wall, one end of the bolt 5 passes through the wall and the gasket assembly and is connected to the external wall fastener 6, and the other end of the bolt 5 is located inside the wall and is connected to the internal wall fastener 7. The internal wall fastener 7 is used to fix the bolt 5 from the inside of the wall, and the external wall fastener 6 is used to fix the bolt from the outside of the wall.

[0037] Because the upper fixing member is the main force point, the pad assembly of the upper fixing member is usually the first pad, the first pad is the pad 81, the bolt 5 passes through the pad 81, the external wall fastener 6 is composed of two steel pipes, a mountain-shaped piece and a nut, the two steel pipes are respectively located on both sides of the bolt 5, and are fixed to the pad 81 by the mountain-shaped piece and the nut, the mountain-shaped piece and the nut are arranged on the bolt 5, and the extension member 4 is connected to one of the steel pipes, such as Figure 1-3 As shown, two steel pipes are usually arranged horizontally, respectively located on the upper and lower sides of the bolt 5, and then fixed in position by a mountain-shaped piece, and the nut is tightened so that the force can be transmitted to the pad 81 through the two steel pipes, and finally act on the outer wall of the wall. By increasing the force-bearing area of ​​the outer wall of the wall, the damage of the formwork support 2 to the wall is reduced.

[0038] The gasket assembly of the wall fixing member at the bottom (the bottom fixing member) is the second gasket, and the second gasket is composed of a steel pipe sleeve 82, which is sleeved outside the bolt 5 and is tightened and fixed by a nut. Figure 1 , 2 As shown in FIG. 4 , the steel pipe sleeve 82 acts as a gasket to increase the contact area with the outer wall of the wall. At the same time, the arrangement of the steel pipe sleeve 82 can provide enough space for connecting the diagonal rod of the formwork support frame 2 therewith, without the need to separately arrange a steel pipe and matching fixings for connecting with the diagonal rod.

[0039] The external protective cantilever frame 1 can be composed of a variety of fasteners, steel pipes, plywood, etc. The formwork support frame 2 is connected to the wall fixing member (upper fixing member) through an extension member 4, and its inclined rod is connected to the steel pipe sleeve 82 on the lowest fixing member;

[0040] The formwork support frame 2 is composed of a support frame upright 21 connected to the extension member 4, a formwork keel 22 located at the top of the support frame upright 21, the diagonal brace, and a diagonal rod 23 located between two adjacent support frame uprights 21, the diagonal brace is connected to the upper and lower extension members 4, it should be noted that the two extension members 4 mentioned here are extension members 4 on the same vertical plane, the top of the diagonal rod 23 is connected to the bottom of the formwork keel 22 through a connector 9, the bottom of the diagonal rod 23 is connected to the support frame upright 21, the angle between the diagonal rod 23 and the formwork keel 22 is not less than 60°, and the support frame upright 21 is connected to the wall fixing member through the extension member 4 for pouring the cantilever eaves;

[0041] By setting the extension piece 4 on the wall fixing piece, the formwork support frame 2 can act on the wall fixing piece, thereby reducing the number of holes punched in the wall, thereby reducing damage to the concrete structure. By setting the diagonal rod and the diagonal rod 23, the stability of the formwork support frame 2 can be effectively increased. The wall fixing piece can effectively increase the force-bearing area of ​​the formwork support frame 2 on the wall and reduce damage to the wall structure. In order to ensure the firmness of the connection, the wall fixing piece located at the top usually needs to be installed on the frame beam 102, and the bottom fixing piece is usually located on the lower floor of the upper fixing piece, such as Figure 2 As shown in . The above is an implementation method for setting wall fixings for closed walls (without openings). When constructing at locations with openings, multiple upper fixings cannot be set because the floors have openings. At this time, in order to avoid unnecessary damage to the wall caused by drilling more holes in the wall and installing more upper fixings, the present application also provides an implementation method for construction at the openings, that is, when constructing at the openings, the present application also includes at least two wall connecting members 3. When constructing at the wall openings, the two wall connecting members 3 are respectively set at the top and bottom of the openings, as shown in . Figure 1 As shown, the wall connecting member 3 can be a clip-on structure, and an extension member 4 is also provided on the wall connecting member 3 for fixing the formwork support frame 2. To ensure the stability and firmness of the structural connection, the extension member 4 of the wall connecting member 3 is usually connected with a steel pipe perpendicular to the extension member 4 through a connecting structure such as a right-angle fastener.

[0042] Because the wall fastener 7 is located on the inner side of the wall, and its main function is to fix the bolt 5 from the inside, nuts and washers can be directly used as the wall fastener 7. During construction, not all holes for installing the bolt 5 are horizontal holes, and the orientation of the holes may vary depending on the construction personnel. Therefore, when the formwork support frame 2 is actually erected, the inclined bolt 5 may be subjected to a pulling force toward the outer wall of the wall. At this time, because the bolt 5 is in a non-horizontal state, the wall fastener 7 is not completely attached to the inner wall of the wall. When the bolt 5 is subjected to tension, the pressure of the wall fastener 7 on the inner wall of the wall is uneven, which may easily damage the inner wall of the wall, and cause the wall fastener 7 and the bolt 5 to be disengaged, bitten, damaged, etc., resulting in the inability to separate the wall fastener 7 from the bolt 5 when the bolt 5 is subsequently removed, or the inner wall of the wall is damaged. To this end, we provide a specific implementation of an internal wall fastener 7, which is composed of an adjusting member, at least three washers and a nut. The bolt 5 passes through the adjusting member, the washers and the nut, and the adjusting member abuts against the inner wall of the wall through the nut. The adjusting member is composed of a fitting member 71 abutting against the inner wall of the wall, and a pressing member 72 movably connected to the fitting member 71. The fitting member 71 is provided with a first through hole, the aperture of which is larger than the diameter of the bolt 5. The pressing member 72 is provided with a second through hole, the aperture of which is adapted to the bolt 5. One end of the pressing member 72 is a plane abutting against the washer, and the other end is a convex spherical surface. One end of the fitting member 71 is a plane abutting against the inner wall of the wall, and the other end is a concave ball groove. The diameter of the ball groove is adapted to the diameter of the convex spherical surface of the pressing member 72. During construction, whether the bolt 5 is in a state vertical to the wall, such as Figure 6 As shown in A, it is still in a state of being inclined toward the wall. Figure 6 As shown in B. The nut, gasket and pressing piece 72 can all remain coaxial with the bolt 5, so as to facilitate the connection and separation of the nut and the bolt 5. Because the inner diameter of the first through hole of the fitting piece 71 is larger than the diameter of the bolt 5, when the bolt 5 is inclined to the wall, the plane of the fitting piece 71 can still be in a state of being in contact with the inner wall of the wall, and the pressing piece 72 can be in contact with the fitting piece 71 through the protruding spherical surface, so as to realize the conversion of the inclined force direction into the force direction perpendicular to the wall, so as to ensure that no matter whether the bolt 5 is in a state of being perpendicular to the wall, the wall fastener 7 can be in surface contact with the wall, so as to avoid damage to the wall and the nut.

[0043] In the prior art, when cantilevering the formwork, the support frame and the protection frame have the problem of poor stability. In the present application, we increase the stability by adding a diagonal rod 23 between the support frame uprights 21 of the formwork support frame 2, limiting the support angle, and adding a diagonal rod connected to the lowest fixing member. The above optimization directions are all optimized for the vertical poles of the formwork support frame 2. In addition to the way the steel pipes that constitute the bracket are erected, the formwork keel 22 of the formwork support frame 2 will also affect the stability of the formwork support frame 2, because the formwork support frame 2 needs to support the formwork through the formwork keel 22. During pouring, the poured concrete will gradually increase the force on the formwork support frame 2 in the vertical direction. Therefore, the firmness between the formwork keel 22 that is directly in contact with the bottom surface of the formwork and the support frame vertical poles 21 and diagonal rods 23 connected thereto is crucial, especially when the formwork keel 22 shakes in the horizontal direction, the force on the diagonal rod 23 is very large. For this reason, in order to ensure the firmness of the connection between the diagonal rod 23 and the formwork keel 22, a connector 9 is provided between the two. The connector 9 is composed of a fixing plate 91 provided with a plurality of third through holes, a first connecting plate 92, a second connecting plate 93 and a third connecting plate 94 provided on the bottom surface of the fixing plate 91. Since the template keel 22 is usually composed of wood and square steel, the fixing plate 91 can be connected to the bottom of the template keel 22 by means of screws, bolts and other structures. The first connecting plate 92 and the third connecting plate 94 are arranged in parallel, and the gap between the two constitutes a limiting groove 95. The first connecting plate 92 is connected to the third connecting plate 94 through the second connecting plate 93. The second connecting plate 93 is provided with a through hole connected to the limiting groove 95. Figure 7 As shown;

[0044] When the diagonal rod 23 is made of steel pipe or square steel, the end of the diagonal rod 23 can be inserted into the connector 9, such as Figure 8 As shown, even if the end of the oblique rod 23 extends into the limiting groove 95 through the through hole and is connected to the bottom surface of the fixing plate 91, it can be a fixed connection, or a plug-in or detachable connection. Because the oblique rod 23 and the support frame upright 21 are connected separately, and the template keel 22 is located above the oblique rod 23, the connection method between the oblique rod 23 and the connector 9 is not limited. It should be noted that the limiting groove 95 formed between the first connecting plate 92 and the third connecting plate 94 can limit the oblique rod 23 inserted into the limiting groove 95;

[0045] When the inclined rod 23 adopts the above-mentioned plug-in connection method, there is a certain limit on the installation angle of the inclined rod 23. Since the connector 9 is an integral body, in order to increase the application range of the connector 9, a mounting hole for mounting the rotating assembly 10 can be provided on the second connecting plate 93, and the end of the inclined rod 23 can be connected to the second connecting plate 93 through the rotating assembly 10. Fig. 9 As shown, the rotating assembly 10 can be a bearing sleeved on a fixed shaft, and the two ends of the fixed shaft are connected to the mounting holes on the second connecting plate 93 by screws, and the outer wall of the bearing is connected to the end of the inclined rod 23, thereby there is no restriction on the installation angle of the inclined rod 23. Usually, the first connecting plate 92 and the third connecting plate 94 are triangular plates, one side of which is connected to the fixed plate 91, and the angle opposite to the side is located below the fixed plate 91, thereby making the through hole of the second connecting plate 93 an inclined hole, and the aperture of the through hole should be larger than the diameter of the inclined rod 23.

[0046] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0047] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A construction method for a cast-in-place roof eaves formwork support frame, characterized in that: include: At least two wall fixings, providing installation support for the formwork support frame (2); An external protective cantilever frame (1) is used to protect the exterior of the wall; The formwork support frame (2) is connected to the wall fixing member and is used for pouring the cantilevered eaves.

2. The construction method of the cast-in-place eaves formwork support frame for the roof according to claim 1, characterized in that: It also comprises at least two wall connecting members (3). When construction is carried out at the position of a wall opening, the two wall connecting members (3) are respectively arranged at the top and bottom of the opening.

3. The construction method of the cast-in-place eaves formwork support frame for the roof according to claim 1 or 2, characterized in that: It also comprises at least one extension piece (4), wherein the extension piece (4) is connected to the wall fixing piece and extends to the outside of the wall, and the formwork support frame (2) is connected to the extension piece (4).

4. The construction method of the cast-in-place eaves formwork support frame of the roof according to claim 3, characterized in that: The wall fixing component is composed of a bolt (5), an external wall fastener (6) located at one end of the bolt (5), an internal wall fastener (7) located at the other end of the bolt (5), and a gasket assembly. The gasket assembly is located on the outer wall of the wall. One end of the bolt (5) passes through the wall and the gasket assembly and is connected to the external wall fastener (6). The other end of the bolt (5) is located on the inner side of the wall and is connected to the internal wall fastener (7).

5. The construction method of the cast-in-place eaves formwork support frame of the roof according to claim 4, characterized in that: The gasket assembly is a first gasket, the first gasket is a gasket plate (81), the bolt (5) passes through the gasket plate (81), the external wall fastener (6) is composed of two steel pipes, a chevron and a nut, the two steel pipes are respectively located on both sides of the bolt (5) and are fixed to the gasket plate (81) by the chevron and the nut, the chevron and the nut are arranged on the bolt (5), and the extension piece (4) is connected to one of the steel pipes.

6. The construction method of the cast-in-place eaves formwork support frame for the roof according to claim 4, characterized in that: The gasket assembly of the wall fixing member located at the bottom is a second gasket, and the second gasket is composed of a steel pipe sleeve (82), and the steel pipe sleeve (82) is sleeved outside the bolt (5).

7. The construction method of the cast-in-place eaves formwork support frame of the roof according to claim 4, characterized in that: The wall fastener (7) is composed of an adjusting piece, at least three washers and a nut, the bolt (5) passes through the adjusting piece, the washers and the nut, and the adjusting piece abuts against the inner wall of the wall through the nut.

8. The construction method of the cast-in-place eaves formwork support frame of the roof according to claim 7, characterized in that: The adjusting member is composed of a fitting member (71) abutting against the inner wall of the wall, and a pressing member (72) movably connected to the fitting member (71); the fitting member (71) is provided with a first through hole, the diameter of which is larger than the diameter of the bolt (5); the pressing member (72) is provided with a second through hole, the diameter of which is adapted to the bolt (5); one end of the pressing member (72) is a plane abutting against the gasket, and the other end is a convex spherical surface; one end of the fitting member (71) is a plane abutting against the inner wall of the wall, and the other end is a concave ball groove, the diameter of which is adapted to the diameter of the convex spherical surface of the pressing member (72).

9. The construction method of the cast-in-place eaves formwork support frame for the roof according to claim 3, characterized in that: The formwork support frame (2) is composed of a support frame upright (21) connected to the extension member (4), a formwork keel (22) located at the top of the support frame upright (21), and an inclined rod (23) located between two adjacent support frame uprights (21), wherein the top of the inclined rod (23) is connected to the bottom of the formwork keel (22) via a connector (9), and the bottom of the inclined rod (23) is connected to the support frame upright (21).

10. The construction method of the cast-in-place eaves formwork support frame of the roof according to claim 9, characterized in that: The connector (9) is composed of a fixing plate (91) provided with a plurality of third through holes, a first connecting plate (92) provided on the bottom surface of the fixing plate (91), a second connecting plate (93) and a third connecting plate (94), wherein the first connecting plate (92) and the third connecting plate (94) are provided in parallel, and a gap between the first connecting plate (92) and the third connecting plate (94) forms a limiting groove (95), the first connecting plate (92) is connected to the third connecting plate (94) via the second connecting plate (93), and the second connecting plate (93) is provided with a through hole communicating with the limiting groove (95); The end of the oblique rod (23) extends into the limiting groove (95) through the through hole and is connected to the bottom surface of the fixing plate (91); Or the end of the inclined rod (23) is connected to the second connecting plate (93) via a rotating assembly (10).

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