Expansion fixing sleeve and invisible connecting piece

Abstract

The utility model relates to the technical field of connecting pieces, and particularly discloses an expansion fixing sleeve and an invisible connecting piece, the expansion fixing sleeve comprises a connecting section and an expansion fixing section, when the expansion fixing sleeve is fixed in a hole of a part to be connected, the expansion fixing section is always in an expansion state under the action of an expansion acting piece, and the invisible connecting piece is fixed. The expansion fixing sleeve is prevented from falling off from the holes of the connecting parts when the two connecting parts are disconnected; a retaining piece is arranged on the side wall of the connecting section, one end of the retaining piece is fixed to the side wall of the connecting section, the other end of the retaining piece is a free end, the free end of the retaining piece can conduct radial displacement under the action of radial pressure, and when the free end is not subjected to external force, the outer wall of the retaining piece protrudes out of the outer wall of the connecting section; the retaining piece moves inwards in the radial direction so that the inner wall of the retaining piece can protrude out of the inner wall of the connecting section. According to the utility model, the invisible connection of two parts can be realized, and the repeated use can be realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to connecting piece technical field, concretely relates to an expansion fixing sleeve and invisible connecting piece. BACKGROUND

[0002] The existing furniture connecting piece adopts the mode of bolt or three-in-one lock catch matched connecting rod to connect, when connecting, the both ends of the connecting rod are inserted into two furniture parts to be connected respectively, then the connecting rod is fixed in the furniture parts through the bolt or three-in-one lock catch, the two furniture parts are connected, the connecting mode leads to the exposure of the bolt or three-in-one lock catch, is not favorable to the structure of the beautiful connecting rod, and the insertion rod 500 in Figure 2 .

[0003] Another connecting mode of the furniture part is to adopt expansion piece to connect to avoid the exposure of the bolt or three-in-one lock catch. Figure 1 The expansion piece mainly includes integral structure and split structure, the integral structure as shown in includes threaded rod 400 and expansion sleeve 300 set in one end of threaded rod 400, when using, the threaded end of threaded rod 400 is fixed in furniture part A, then one end provided with expansion sleeve 300 is inserted into furniture part B by external force, expansion sleeve 300 is fixed in furniture part B by the elastic action of expansion sleeve 300, and the connection of furniture part A and furniture part B is realized. The integral structure can only realize one-time connection, when furniture part A and furniture part B are separated, the expansion sleeve 300 end is pulled out under the action of external force, and the wood chips in the hole of furniture part B are taken out, so that the hole diameter of furniture part B is enlarged, when the expansion sleeve 300 is inserted for the second time, effective connection cannot be realized.

[0004] The split structure as shown in Figure 2As shown, including iron sleeve 300 and insert rod 500, one end of insert rod 500 is threaded section, one end of iron sleeve 300 is expansion end 301, expansion end 301 is formed by a plurality of hooks 3011, the expansion end 301 is opened under the support of the insert rod 500, because the iron sleeve 300 is not elastic, in order to realize the insert rod 500 is inserted into the iron sleeve 300, the inner diameter of the iron sleeve 300 needs to be set to be greater than the maximum outer diameter of the insert rod 500, in use, first, the threaded section of the insert rod 500 is fixed in the furniture part A, then the expansion sleeve 300 is placed in the furniture part B, the expansion end 301 is arranged inward, then the furniture part A and the furniture part B are hit, the insert rod 500 is inserted into the expansion sleeve 300, the expansion end 301 is opened and fixed in the furniture part B, and then the connection of the furniture part A and the furniture part B is realized. The split structure has the following problems: 1) the contact area of the hook 3011 and the hole wall of the furniture part B is small, only the outer edge of the hook 3011 contacts the hole wall of the furniture part B, so that the connection stability of the expansion sleeve 300 and the furniture part B is not good; 2) the iron sleeve 300 and the insert rod 500 are only connected at the most protruding part of the inner side of the hook 3011, so that the connection stability of the iron sleeve 300 and the insert rod 500 is not good; 3) the expansion end 301 is opened by the end of the insert rod 500 away from the threaded section, which requires that the depth of the insert rod 500 inserted into the iron sleeve 300 must be suitable, but the depth of the insert rod 500 inserted into the iron sleeve 300 cannot be accurately controlled, or the insertion length is too short, so that the expansion end 301 cannot be expanded, or the insertion length is too long, so that the insert rod 500 has no contact with the expansion end 301, so that the iron sleeve 300 and the insert rod 500 cannot be effectively connected. Utility model content

[0005] The utility model discloses a kind of expansion fixing sleeve and invisible connecting piece, which can not only realize the invisible connection of two components, but also be reused.

[0006] The utility model realizes by the following technical scheme:

[0007] An expansion fixing sleeve includes a connecting section and an expansion fixing section, and an axial through hole is formed in the connecting section. When the expansion fixing sleeve is fixed in a hole of a component to be connected, the expansion fixing section is always in an expanded state under the action of an expansion element, preventing the expansion fixing sleeve from falling out of the hole of the component to be connected when the two connected components are disconnected, i.e., separated.

[0008] A side wall of the connecting section is provided with a retreat-stop piece, one end of which is fixed to the side wall of the connecting section, and the other end is a free end. The free end of the retreat-stop piece can be radially displaced under the action of a radial pressure.

[0009] The main difference between the utility model and the expansion sleeve of the existing expansion connecting piece is that:

[0010] 1) when in use, the expansion fixing section is always in an expanded state under the action of the expansion action member, i.e. after the expansion fixing sleeve is fixed to the to-be-connected component by the expansion action member, it is fixed to the connected component during use and will not fall off the connected component due to separation of the two components, i.e. the expansion action member functions to achieve expansion fixing of the expansion section and prevent the expansion fixing sleeve from falling off the hole of the to-be-connected component when the to-be-connected component is disconnected;

[0011] 2) the side wall of the expansion fixing sleeve is provided with a retreat-stop piece, which functions to connect the expansion fixing sleeve to the connecting rod for connecting the two components after the two components are connected, and when the pulling force reaches a certain value, the connecting rod and the retreat-stop piece can be separated, thereby achieving separation of the two connected components, and the expansion fixing sleeve is still fixed to one of the components for next connection, and the expansion fixing sleeve is usually reused for 2-3 times before it is disabled.

[0012] In summary, the expansion fixing sleeve designed in the utility model can achieve invisible connection of two components and can be reused.

[0013] In order to ensure that the expansion fixing sleeve is still fixed to the hole of one of the connected components when the two connected components are separated, the pulling force of the expansion fixing section is set to be greater than the pulling force of the retreat-stop piece.

[0014] In a preferred mode, when not subjected to external force, the outer wall of the retreat-stop piece protrudes from the outer wall of the connecting section, and when subjected to extrusion of the hole wall, the retreat-stop piece moves inward along the radial direction so that the inner wall of the retreat-stop piece protrudes from the inner wall of the connecting section; when subjected to extrusion of the hole wall, the retreat-stop piece moves inward along the radial direction so that the bottom of the groove is broken or deformed to protrude from the inner wall of the connecting section; when the retreat-stop piece is subjected to extrusion of the hole wall, the retreat-stop piece moves inward along the radial direction so that the inner wall of the connecting section is deformed to form a protrusion.

[0015] In a preferred mode, the expansion action member is arranged in the connecting section, and axial displacement of the expansion action member is used to achieve expansion of the expansion fixing section.

[0016] The utility model directly places the expansion action member in the expansion fixing sleeve, inserts the connecting rod for connection into the expansion fixing sleeve, uses the connecting rod to achieve axial displacement of the expansion action member, pushes the expansion action member to the expansion fixing section, and achieves expansion and fixing of the expansion fixing sleeve in the to-be-connected component.

[0017] In a preferred mode, a limiting block is arranged on the inner wall of the connecting section, and a protrusion is arranged on the lower part of the outer wall of the expansion action member, and the limiting block and the protrusion have an overlapping part in the radial direction to achieve blocking and limiting of the protrusion by the limiting block.

[0018] In a preferred mode, the shape of the expansion member comprises an equal-diameter cylinder, a cross or a cylinder with a protrusion.

[0019] In a preferred mode, the expansion fixing section comprises at least two expansion petals, and the plurality of expansion petals can be expanded under the action of the expansion member.

[0020] In a preferred mode, the expansion petal comprises an equal-diameter section and a variable-diameter section, and the variable-diameter section is connected to the connecting section at one end, and the radial thickness of the variable-diameter section gradually increases from the end connected to the connecting section to the other end.

[0021] The expansion member with the above structure is beneficial to the expansion of the expansion fixing section formed by the plurality of expansion petals under the axial thrust of the expansion member inserted between the plurality of expansion petals.

[0022] In a preferred mode, the inner walls of the equal-diameter section and the variable-diameter section are circularly arcuate, which is beneficial to the axial displacement of the expansion member.

[0023] In a preferred mode, the anti-back-off piece comprises a fixing section and an anti-back-off section, the fixing section is fixed to the side wall of the connecting section at one end, the inner walls of the fixing section and the anti-back-off section are flush, and the outer wall of the anti-back-off section protrudes from the fixing section.

[0024] That is, the thickness of the anti-back-off section of the anti-back-off piece is greater than the thickness of the fixing section, which is more beneficial to the radial movement of the anti-back-off section under the radial force, and the radial movement of the anti-back-off piece can be understood as the radial swing of the anti-back-off section with the connecting position of the fixing section to the side wall of the connecting section as the fixed point, that is, the free end of the anti-back-off piece of the utility model can swing under the radial force.

[0025] In a preferred mode, the side wall of the connecting section is provided with a through hole, and the bottom of the anti-back-off piece is fixed in the through hole.

[0026] In a preferred mode, the free end of the anti-back-off piece and the through hole have a gap one.

[0027] In a preferred mode, the circumferential side wall of the anti-back-off piece and the through hole have a gap two.

[0028] That is, the anti-back-off piece of the utility model has a gap between the remaining side walls and the through hole except that one end of the anti-back-off piece is fixed to the through hole, which is more beneficial to the radial movement of the anti-back-off piece.

[0029] In a preferred mode, the outer wall of the expansion fixing sleeve is provided as a rough surface.

[0030] The rough surface can increase the friction between the expansion fixing and the inner wall of the hole of the connecting component, and improve the stability of the expansion fixing sleeve fixed in the hole.

[0031] In a preferred mode, the way of forming the rough surface comprises:

[0032] The outer wall of the expansion fixing sleeve is provided with a plurality of annular grooves, or the outer wall of the expansion fixing sleeve is provided with a threaded surface or a checkered surface.

[0033] The invisible connecting piece comprises a connecting rod and an expansion fixing sleeve.

[0034] The connecting rod comprises a threaded fixing section and an insertion connecting section, the threaded fixing section is inserted into a hole of another component to be connected in use, and the outer wall of the insertion connecting section is provided with a locking piece matched with the retreat stopper; the insertion connecting section is used for inserting the expansion fixing sleeve and pushing the expansion piece to axially displace.

[0035] The invisible connecting piece of the utility model is connected by the cooperation of the retreat stopper and the locking piece, which can not only meet the connection of two components, but also realize the separation of the connecting rod and the expansion fixing sleeve when a certain pressure is applied to the two components, because the expansion fixing sleeve is fixed to one of the components by the expansion fixing piece, and thus the separation of the two connected components is realized, and the separated expansion fixing sleeve is still fixed in one of the components, so that the next connection of the two components can be realized.

[0036] In a preferred mode, the locking piece is in the form of a reverse thread, a thread, a pineapple thread, an annular protrusion or a bump.

[0037] In a preferred mode, the outer wall of the locking piece protrudes from the outer wall of the insertion connecting section, that is, the maximum outer diameter of the locking piece is greater than the outer diameter of the insertion connecting section, so as to adapt to the tolerance of the holes of the two connected components.

[0038] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0039] 1. The utility model improves the structure of the existing expansion sleeve, realizes the improvement of the fixing mode and the connecting mode, and all the prior arts use an insertion rod to insert the expansion sleeve and realize the expansion of the expansion sleeve by the insertion rod, that is, the prior art directly realizes the expansion and fixing of the expansion sleeve by an insertion rod and the connection of the insertion rod and the expansion sleeve, but in the utility model, the expansion and fixing of the expansion fixing sleeve realizes the connection of the expansion fixing sleeve and another component by two different structures: the expansion and fixing of the expansion fixing sleeve is realized by the expansion piece, and the detachable connection of the connecting rod for connecting the two components and the retreat stopper is realized, the connecting rod and the retreat stopper can be separated when the pulling force reaches a certain value, and thus the two connected components can be separated, and the expansion fixing sleeve is still fixed in one of the components for the next connection, and the expansion fixing sleeve will be invalid after being repeatedly used for 2-3 times, that is, the expansion fixing sleeve of the utility model can not only realize the invisible connection of the two components, but also can be repeatedly used.

[0040] 2. The invisible connecting piece, comprising a connecting rod and an expansion fixing sleeve, through setting the locking piece matched with the stopper piece on the expansion fixing sleeve on the connecting rod, not only the connecting rod and the expansion fixing sleeve can be connected, but also the connecting rod and the expansion fixing sleeve can be separated, when using, the expansion fixing sleeve is fixed in the hole of one of the connecting parts, the threaded fixing section of the connecting rod is inserted into the hole of the other connecting part, then the insertion connecting section of the connecting rod is inserted into the expansion fixing sleeve to realize the connection of the connecting rod and the expansion fixing sleeve, when the two parts are connected, the connecting rod and the expansion fixing sleeve are in the hole and cannot be exposed, the invisible connection is realized, and the connecting rod and the expansion fixing sleeve can be separated and used again, the problem that the existing expansion connecting piece cannot be reused is solved. BRIEF DESCRIPTION OF DRAWINGS

[0041] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application. In the drawings:

[0042] Figure 1 It is a schematic view of the integral structure in the prior art;

[0043] Figure 2 It is a schematic view of the split structure in the prior art;

[0044] Figure 3 It is a perspective view of the expansion fixing sleeve in embodiment 1 of the present application;

[0045] Figure 4 It is a front view of the expansion fixing sleeve in embodiment 1 of the present application;

[0046] Figure 5 It is a sectional view of the expansion fixing sleeve in embodiment 1 of the present application;

[0047] Figure 6 It is a structural schematic view of the connecting rod of the present application;

[0048] Figure 7 It is a structural schematic view of the stopper piece in embodiment 1 of the present application;

[0049] Figure 8 It is a partial sectional view of the expansion fixing sleeve Figure 1 ;

[0050] Figure 9 It is a partial sectional view of the expansion fixing sleeve Figure 2 ;

[0051] Figure 10 It is a schematic view of the connection of the furniture plate A and the furniture plate B in embodiment 3 after connection;

[0052] Figure 11 It is a front view of the expansion fixing sleeve in embodiment 3.

[0053] Figure 12 is a partial sectional view of the expansion fixing sleeve in Example 3;

[0054] Figure 13 is a partial schematic view of the expansion fixing sleeve in Example 4.

[0055] Markings in the drawings and corresponding names of parts:

[0056] 1-expansion fixing section; 2-connection section; 3-1-retaining piece one; 3-2-retaining piece two; 3-3-retaining piece three; 4-expansion acting piece;

[0057] 11-expansion petal; 21-through hole; 22-limiting block; 23-gap one; 24-gap two; 25-groove; 26-axial through hole; 31-fixing section; 32-retaining section; 41-protrusion;

[0058] 111-equal-diameter section; 112-variable-diameter section;

[0059] 100-expansion fixing sleeve; 200-connection rod; 300-iron sleeve; 400-threaded rod; 500-insertion rod; 600-furniture plate A; 700-furniture plate B;

[0060] 201-insertion connection section; 202-threaded fixing section; 203-locking piece; 204-top cap;

[0061] 301-expansion end; 3011-catch. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and advantages of the present application more clearly understood, the present application will be further described in detail below with embodiments, the illustrative embodiments of the present application and the description thereof are only used to explain the present application, and do not limit the present application, the following described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0063] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application can be practiced without these specific details. In other embodiments, in order to avoid obscuring the present application, well-known structures, materials or methods are not specifically described. The materials, instruments and reagents used in the following embodiments, etc. can be obtained from commercial channels if not otherwise specified. The technical means used in the embodiments, if not otherwise specified, are conventional means known to those skilled in the art.

[0064] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0065] Example 1:

[0066] To address the problem that expansion joints used for furniture connections in existing technologies cannot be reused, such as... Figures 3-7 As shown, this embodiment provides an expansion fixing sleeve, including a connecting section 2 and an expansion fixing section 1. The connecting section 2 and the expansion fixing section 1 are preferably integrally formed. An axial through hole 26 is formed within the connecting section 2, and the end of the connecting section 2 away from the expansion fixing section 1 is designated as the inlet end. The expansion fixing section 1 includes at least two expansion petals 11, with a circumferential gap between adjacent expansion petals 11 in the circumferential direction, and a central gap is formed between the multiple expansion petals 11 on the central side. This central gap communicates with the axial through hole 26, and the multiple expansion petals 11 can expand under the action of the expansion member 4. In a specific case, such as... Figure 3 As shown, the expansion fixing section 1 is composed of four expansion petals 11 evenly arranged in the circumferential direction. In a preferred embodiment, to better achieve the expansion fixing section 1 expanding under external force, the expansion petal 11 includes a constant diameter section 111 and a variable diameter section 112. One end of the variable diameter section 112 is connected to the connecting section 2, and the radial thickness of the variable diameter section 112 gradually increases from the end connected to the connecting section 2 to the other end. That is, a frustum-shaped hole is set at the lower end of the multiple expansion petals 11, specifically referring to the external force inlet end. More preferably, the inner walls of the constant diameter section 111 and the variable diameter section 112 are rounded. In this embodiment, when the expansion fixing segment 1 expands and is fixed in the hole of the component to be connected under the action of the expansion member 4, the outer wall of the expansion petal 11 is in contact with the hole wall. That is, when the expansion fixing segment 1 expands and is fixed, there is a large contact area between it and the hole wall. Therefore, the expansion fixing sleeve has good stability in the hole. In addition, the equal diameter segment 111 of the expansion fixing segment 1 has a certain length in the circumferential direction. As long as the expansion member 4 enters the equal diameter segment 111 side, the expansion fixing segment 1 can be expanded. There is no need to precisely control the length of the expansion member 4 entering the expansion fixing segment 1, which improves the convenience of operation.

[0067] When the expansion fixing sleeve 100 is fixed in the hole of the component to be connected, the expansion fixing section 1 is always in the expanded state under the action of the expansion action piece 4, preventing the expansion fixing sleeve 100 from falling out of the hole of the component to be connected when the two connected components are disconnected, i.e. separated, that is, when the expansion fixing sleeve 100 is fixed in the hole of one of the connected components by the expansion action piece 4, even if the two connected components are separated under the action of external force, the expansion fixing sleeve 100 will not fall off and will always be placed in the hole of the connected component; that is, in this embodiment, the expansion action piece 4 first provides radial pressure to the expansion fixing section 1 to expand the expansion fixing section 1, and then is fixed in the hole of the component to be connected. The components to be connected in this embodiment can be any two components that need to be connected, such as furniture boards, etc. In order to better illustrate the technology, the two components to be connected are defined as furniture board A 600 and furniture board B 700.

[0068] In this embodiment, the specific shape and placement position of the expansion action piece 4 are not limited, as long as it can act on the expansion fixing section 1 under the action of external force. For example: the expansion action piece 4 can be placed separately outside the expansion fixing sleeve 100, when needed, the expansion action piece 4 is inserted into the connecting section 2 from the opening end away from the expansion fixing section 1, then the expansion fixing sleeve is inserted into the hole of the furniture board A 600, and finally the expansion action piece 4 is pushed into the expansion fixing section 1 by applying an axial pushing force to expand the expansion fixing section 1 and fix the expansion fixing sleeve in the hole of the furniture board A 600. In a preferred case, the expansion action piece 4 is arranged below the expansion fixing section 1 in the expansion fixing sleeve 100, and the expansion of the expansion fixing section 1 is achieved by the axial displacement of the expansion action piece 100. The expansion action piece 4 can be directly placed in the expansion fixing sleeve 100, or can be connected with the expansion fixing sleeve 100, and the connection is disconnected under the action of the axial pushing force. Preferably, when the expansion action piece 4 is directly placed in the expansion fixing sleeve 100, as shown in Figure 8 The limiting block 22 is arranged on the inner wall of the connecting section 2, and the protrusion 41 is arranged on the lower part of the outer wall of the expansion action piece 4, and the limiting block 22 and the protrusion 41 have an overlapping part in the radial direction to achieve the blocking and limiting of the limiting block 22 to the protrusion 41, that is, after the expansion action piece 4 is placed in the connecting section 2, the axial ends of the expansion action piece 4 are respectively limited by the limiting block 22 and the expansion fixing section 1 to improve the stability of the expansion action piece 4 placed in the connecting section 2. The shape of the expansion action piece 4 includes an equal-diameter cylinder, a cross, or a cylinder with a protruding part. When the expansion action piece 4 is an equal-diameter cylinder, as shown in Figure 5As shown, when the expansion member 4 is subjected to axial thrust, since the outer diameter of the expansion member 4 is greater than the width of the central gap formed between the plurality of expansion petals 11, when the expansion member 4 enters between the plurality of expansion petals 11, the plurality of expansion petals 11 are expanded, realizing the expansion of the expansion fixing section 1 to fix the expansion fixing sleeve in the hole of the furniture plate A; the cross and the column with the protruding part are the same, which are based on the principle that the outer diameter of the expansion member 4 is greater than the width of the central gap formed between the plurality of expansion petals 11 to realize the expansion of the expansion fixing section 1.

[0069] The side wall of the connecting section 2 is provided with a retreat stop piece one 3-1, one end of the retreat stop piece one 3-1 is fixed on the side wall of the connecting section 2, and the other end is a free end. The free end of the retreat stop piece one 3-1 can be radially displaced under the action of radial pressure. When not subjected to external force, the outer wall of the retreat stop piece one 3-1 protrudes from the outer wall of the connecting section 2. When subjected to extrusion by the hole wall, the retreat stop piece one 3-1 moves inward along the radial direction so that the inner wall of the retreat stop piece one 3-1 protrudes from the inner wall of the connecting section 2.

[0070] In this embodiment, the tension of the expansion fixing section 1 is greater than the tension of the retreat stop piece one 3-1, so that when the two connected parts are separated under a certain tension, the expansion fixing sleeve 100 can still be fixed in the hole of one of the connected parts under the action of the expansion fixing section 1.

[0071] Specifically, a through hole 21 is arranged on the side wall of the connecting section 2, which communicates the radial inner side and the radial outer side of the connecting section 2. The bottom of the retreat stop piece one 3-1 is fixed in the through hole 21. The bottom of the retreat stop piece one 3-1 refers to the side close to the opening end of the expansion fixing sleeve 100. Preferably, as shown in the figure, Figure 9 As shown, the free end of the retreat stop piece one 3-1 has a gap one 23 with the through hole 21. Further preferably, the circumferential side wall of the retreat stop piece one 3-1 has a gap two 24 with the through hole 21, which is more conducive to the radial displacement of the free end of the retreat stop piece one 3-1 under the action of radial force. The free end of the retreat stop piece one 3-1 in this embodiment can swing in the through hole 21 under the action of radial force.

[0072] The free end of the retreat stop piece one 3-1 is away from or close to the expansion fixing section 1. In an optional case, as shown in the figure, Figure 4 The through hole 21 is a square hole. The through hole 21 has a certain length in the axial direction, and the through hole 21 has the same circumferential width from top to bottom. One end of the retreat stop piece one 3-1 is fixed at the bottom of the through hole 21, so that the top of the retreat stop piece one 3-1, i.e. the end close to the expansion fixing section 1, forms a free end. In this case, top and bottom are relative to Figure 4 The free end of this embodiment specifically refers to the end not connected with the inner wall of the through hole 21.

[0073] In another alternative case, the through hole 21 is still a square hole, and the difference from the above-mentioned alternative case is that one end of the first stopper piece 3-1 is fixed at the top of the through hole 21, so that the bottom of the first stopper piece 3-1, i.e., the end away from the expansion fixing section 1, forms a free end.

[0074] In the present embodiment, the number of the first stopper pieces 3-1 is at least two, and preferably, when the number of the first stopper pieces 3-1 is two, the two first stopper pieces 3-1 are symmetrically arranged with the central axis of the connecting section 2 as the center, and when the number of the first stopper pieces 3-1 is three, the three first stopper pieces 3-1 are evenly arranged in the circumferential direction of the connecting section 2.

[0075] In the present embodiment, the circumferential gap length between different adjacent two expansion petals 11 can be the same or different, for example, as shown in Figure 3 the circumferential gap length above the first stopper piece 3-1 is smaller than the circumferential gap length on both sides of the first stopper piece 3-1, and the bottom of the circumferential gap on both sides of the first stopper piece 3-1 is higher than the top of the first stopper piece 3-1 or the bottom of the circumferential gap on both sides of the first stopper piece 3-1 can extend downward to the bottom of the first stopper piece 3-1 or to any position between the top and the bottom of the first stopper piece 3-1.

[0076] In a preferred embodiment, the outer wall of the expansion fixing sleeve 100 is provided with a rough surface. The rough surface can be formed in the following ways:

[0077] The outer wall of the expansion fixing sleeve 100 is provided with a plurality of annular grooves, as shown in Figures 3-5 or the outer wall of the expansion fixing sleeve 100 is provided with a threaded surface or a checkered surface. The rough surface has the effect of increasing the friction between the expansion fixing sleeve 100 and the hole wall after the expansion fixing sleeve 100 is fixed in the hole of the furniture plate A600, thereby improving the stability of the expansion fixing sleeve 100 fixed in the hole.

[0078] The material of the expansion fixing sleeve 100 of the present embodiment is not limited, as long as it can functionally meet the needs, which can be plastic or metal, etc.

[0079] Embodiment 2:

[0080] The present embodiment is based on Embodiment 1, and the shape of the first stopper piece 3-1 is further limited in the present embodiment to facilitate better radial displacement of the free end of the first stopper piece 3-1 under the action of the radial force.

[0081] In the embodiment, the retreat-stop piece 3-1 comprises a fixing segment 31 and a retreat-stop segment 32; the fixing segment 31 is fixed at one end on the side wall of the connecting segment 2; the outer wall of the retreat-stop segment 32 protrudes from the fixing segment 31. The specific shape of the fixing segment 31 and the retreat-stop segment 32 is not limited, as long as the corresponding functions are met, wherein the fixing segment 31 meets the requirement of fixing the retreat-stop piece 1-3-1 in the through hole 21, and the retreat-stop segment 32 meets the requirement of connecting the expansion fixing sleeve 100 with the connecting rod 200.

[0082] In an optional case, as shown in Figure 3 , the fixing segment 31 and the retreat-stop segment 32 are both arc-shaped blocks, the inner walls of the fixing segment 31 and the retreat-stop segment 32 are flush, and the thickness of the fixing segment 31 is smaller than the thickness of the retreat-stop segment 32, which is beneficial to the radial displacement of the free end of the retreat-stop piece 1-3-1.

[0083] In another optional case, not shown in the figure, the retreat-stop segment 32 is an arc-shaped block, and the fixing segment 31 is composed of at least one connecting piece, one end of the connecting piece is connected with the inner wall of the through hole 21, and the other end is connected with the retreat-stop segment 32. When there are at least two connecting pieces, there is a gap between the adjacent two connecting pieces. The specific shape of the connecting piece is not limited, and it can be a columnar body or a plate structure.

[0084] Embodiment 3:

[0085] As shown in Figure 11 , Figure 12 , the embodiment is based on embodiment 1, and the difference from embodiment 1 is that the structure of the connecting segment 2 is different. In the embodiment, the side wall of the connecting segment 2 is inwardly recessed to form a groove 25, and the retreat-stop piece 2-3-2 is arranged in the groove 25. When the retreat-stop piece 2-3-2 is extruded by the hole wall, the bottom of the groove 25 is broken, so that the inner wall of the retreat-stop piece 2-3-2 protrudes from the inner wall of the connecting segment 2 or the bottom of the groove 25 is deformed to protrude from the inner wall of the connecting segment 2.

[0086] In the embodiment, in the initial state, the inner wall of the retreat-stop piece 2-3-2 is in contact with the bottom of the groove 25, and the outer wall of the retreat-stop piece 2-3-2 protrudes from the outer wall of the connecting segment 2. After the expansion fixing sleeve 100 is inserted into the hole of the furniture plate A600, the retreat-stop piece 2-3-2 is extruded by the hole wall of the hole of the furniture plate A600, and a radial force is applied to the bottom of the groove 25, so that the bottom of the groove 25 is deformed to protrude from the inner wall of the connecting segment 2 or broken.

[0087] In the embodiment, the connection mode of the retreat-stop piece 2-3-2 and the groove 25 is not limited, which can be one end fixed and the other end free as in embodiment 1, or both ends fixed.

[0088] Embodiment 4:

[0089] As shown in Figure 13As shown, the embodiment is based on embodiment 1, and the difference from embodiment 1 is that the structure of connecting section 2 is different, in this embodiment, the side wall of connecting section 2 is not designed with through hole 21, and directly on the side wall of connecting section 2 is arranged retreat-stop piece three 3-3, when expansion fixing sleeve 100 is inserted into the hole of furniture plate A600, retreat-stop piece three 3-3 is extruded by the hole wall of the hole of furniture plate A600, radial force is applied to the side wall of connecting section 2, and the side wall of connecting section 2 is deformed to form a protrusion inward.

[0090] Embodiment 5:

[0091] As Figures 3-7 shown, a hidden connecting piece, comprising a connecting rod 200, an expansion action piece 4, and the expansion fixing sleeve 100 of any one of embodiments 1-4; the following is described with the expansion fixing sleeve 100 of embodiment 1;

[0092] The connecting rod 200 comprises a threaded fixing section 202 and an insertion connecting section 201. The threaded fixing section 202 is inserted into a hole of another component to be connected, i.e. the furniture plate B in use. The insertion connecting section 201 is connected to the threaded fixing section 202 at one end, and the outer wall of the insertion connecting section 201 is provided with a locking piece 203 which cooperates with the anti-backout piece 1 3-1. When the insertion connecting section 201 is inserted into the expansion fixing sleeve 100, the other end of the insertion connecting section 201 pushes the expansion piece 4 to axially displace. When the expansion piece 4 is pushed into the expansion fixing section 1, the locking piece 203 enters the position corresponding to the anti-backout piece 1 3-1, and the locking piece 203 and the anti-backout piece 1 3-1 apply radial force. The anti-backout piece 1 3-1 has a certain restoring force under the radial force of the hole wall and the anti-backout piece 1 3-1 on both sides, and the restoring force realizes the clamping and fixing of the connecting rod 200. Thus, the effective connection of the connecting rod 200 and the expansion fixing sleeve 100 is realized, and since the anti-backout piece 1 3-1 has a certain length in the axial direction, the connection stability of the connecting rod 200 and the expansion fixing sleeve 100 is good, i.e. the anti-backout piece 1 3-1 of the embodiment has a blocking and positioning effect on the withdrawal of the connecting rod 200. Specifically, the form of the locking piece 203 includes reverse thread, thread, pineapple thread, annular protrusion or bump. Preferably, the length of the locking piece 203 in the axial direction is equivalent to the length of the anti-backout piece 1 3-1 in the axial direction, and further preferably, when the connecting rod 200 is connected to the expansion fixing sleeve 100, the top of the locking piece 203 is slightly lower than the top of the anti-backout piece 1 3-1, so that the problem of the top of the anti-backout piece 1 3-1 being stuck in the annular groove of the locking piece 203 to cause the withdrawal failure when the connecting rod 200 is pulled out of the expansion fixing sleeve 100 is avoided. Or preferably, a circular arc chamfer is arranged inside the top of the anti-backout piece 1 3-1, so that even if the top of the locking piece 203 is higher than the top of the anti-backout piece 1 3-1, the connecting rod 200 can be pulled out of the expansion fixing sleeve 100 under a certain pulling force. During the pulling process, since the pulling force of the expansion fixing section 1 is greater than the pulling force of the anti-backout piece 1 3-1, when the pulling force applied to the two connected furniture plates is between the pulling force of the expansion fixing section 1 and the pulling force of the anti-backout piece 1 3-1, the connecting rod 200 can be pulled out of the expansion fixing sleeve 100. Since the pulling force of the expansion fixing section 1 has not been reached, the expansion fixing sleeve 100 will not be pulled out. In the embodiment, the pulling force of the anti-backout piece 1 3-1 specifically refers to the pulling force for separating the connecting rod 200 and the expansion fixing sleeve 100, and the pulling force of the expansion fixing section 1 specifically refers to the pulling force for pulling the expansion fixing sleeve 100 out of the hole.

[0093] In the embodiment, since the anti-backout piece 1 3-1 has a certain length in the axial direction, the connecting rod 200 and the expansion fixing sleeve 100 have a large contact area after being connected, which can ensure the connection stability of the connecting rod 200 and the expansion fixing sleeve 100.

[0094] Preferably, one end of the insertion connecting section 201 is connected with the threaded fixing section 202, and the other end is provided with a top cap 204; when the insertion connecting section 201 is inserted into the expansion fixing sleeve 100, the expansion acting member 4 is pushed to move axially by the top cap 204; the outer diameter of the top cap 204 is larger than the outer diameter of the insertion connecting section 201.

[0095] The working principle of the embodiment is as follows:

[0096] The expansion fixing sleeve 100 is inserted into the hole of the furniture plate A 600, under the action of the hole wall, the stop piece one 3-1 swings inward, so that the inner wall of the stop piece one 3-1 protrudes from the inner wall of the expansion fixing sleeve 100, the threaded fixing section 202 of the connecting rod 200 is fixed in the hole of the furniture plate B 700, and then the insertion connecting section 201 of the connecting rod 200 is inserted into the expansion fixing sleeve 100 from the inlet end of the connecting section 2, in the insertion process, the top or top cap 204 of the insertion connecting section 201 pushes the expansion acting member 4 into the expansion fixing section 1, in this process, the locking member 203 applies a radial outward pushing force to the stop piece one 3-1, when the connecting rod 200 is inserted into the specified position, the stop piece one 3-1 is subjected to the double pressure of the hole wall and the radial two sides of the connecting rod 200, has the restoring force, realizes the clamping fixing of the locking member 203 of the connecting rod 200. Only when the applied pulling force reaches a certain value, the connecting rod 200 can be pulled out of the expansion fixing sleeve 100, for example, when 30-20 Kg pulling force is applied to the furniture plate A 600 or the furniture plate B 700, the connecting rod 200 can be pulled out of the expansion fixing sleeve 100, at this time, the expansion fixing sleeve 100 is still fixed in the hole of the furniture plate A 600 under the action of the expansion acting member 4, for next connection. The connected furniture plate A 600 and the furniture plate B 700 are as shown in Figure 10 .

[0097] In a preferred case, the outer wall of the locking member 203 protrudes from the outer wall of the insertion connecting section 201, that is, the maximum outer diameter of the locking member 203 is greater than the outer diameter of the insertion connecting section 201, so that the hole of the furniture plate A 600 and the hole of the furniture plate B 700 have a tolerance.

[0098] The above specific embodiments further illustrate the purpose, technical scheme and beneficial effects of the utility model, and it should be understood that the above description is only a specific embodiment of the utility model, and is not used to limit the protection scope of the utility model, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the utility model should be included in the protection scope of the utility model.

[0099] It should be noted that the structure, proportion, size and the like shown in the drawings attached to the present specification are only used to cooperate with the content disclosed in the specification, so as to be understood and read by those skilled in the art, and do not define the limiting conditions for the implementation of the present application, so it does not have substantial technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size does not affect the effect and purpose that can be achieved by the present application, and should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and the like in the present specification are only for the convenience of clear description, and are not used to limit the scope of the present application. The change or adjustment of the relative relationship is also considered as the implementation of the present application without substantial changes in technical content.

Claims

1. An inflatable fixing sleeve, characterized in that, The connecting section (2) is provided with an axial through hole (26); when the expansion fixing sleeve (100) is fixed in the hole of the component to be connected, the expansion fixing section (1) is expanded by the axial displacement of the expansion effect part (4); and the expansion fixing section (1) is always in the expanded state under the action of the expansion effect part (4). The side wall of the connecting section (2) is provided with a through hole (21); the through hole (21) is provided with a retreat prevention piece one (3-1), one end of the retreat prevention piece one (3-1) is fixed in the through hole (21), the other end is a free end, the free end of the retreat prevention piece one (3-1) can be radially displaced under the action of radial pressure; or the side wall of the connecting section (2) is recessed inward to form a groove (25), the groove (25) is provided with a retreat prevention piece two (3-2), when the retreat prevention piece two (3-2) is extruded by the hole wall, the bottom of the groove (25) is broken or protrudes from the inner wall of the connecting section (2); or the outer wall of the connecting section (2) is provided with a retreat prevention piece three (3-3).

2. An inflatable fixing sleeve according to claim 1, wherein When not subjected to external force, the outer wall of the retreat prevention piece one (3-1) protrudes from the outer wall of the connecting section (2), when extruded by the hole wall, the retreat prevention piece one (3-1) moves inward along the radial direction to make the inner wall of the retreat prevention piece one (3-1) protrude from the inner wall of the connecting section (2); the outer wall of the retreat prevention piece two (3-2) protrudes from the outer wall of the connecting section (2), when extruded by the hole wall, the retreat prevention piece two (3-2) moves inward along the radial direction to make the bottom of the groove (25) broken or the bottom of the groove (25) deformed to protrude from the inner wall of the connecting section (2); when the retreat prevention piece three (3-3) is extruded by the hole wall, the retreat prevention piece two (3-2) moves inward along the radial direction to make the inner wall of the connecting section (2) deformed to form a protrusion.

3. An inflatable fixing sleeve according to claim 1, wherein The expansion effect part (4) is arranged in the connecting section (2).

4. An inflatable fixing sleeve according to any one of claims 1 to 3, wherein The shape of the expansion effect part (4) includes an equal-diameter cylinder, a cross, or a cylinder with a protrusion.

5. An inflatable restraint according to claim 1, wherein, The expansion fixing section (1) includes at least two expansion petals (11), and a plurality of expansion petals (11) can be expanded under the action of the expansion effect part (4).

6. An inflatable fixing sleeve according to claim 5, wherein The expansion petals (11) include an equal-diameter section (111) and a variable-diameter section (112), one end of the variable-diameter section (112) is connected to the connecting section (2), and the radial thickness of the variable-diameter section (112) gradually increases from one end connected to the connecting section (2) to the other end.

7. An inflatable fixing sleeve according to claim 6, wherein The inner walls of the equal-diameter section (111) and the variable-diameter section (112) are circularly arcuate.

8. An inflatable restraint according to claim 1, wherein, The retreat prevention piece one (3-1) includes a fixed section (31) and a retreat prevention section (32); one end of the fixed section (31) is fixed to the inner wall of the through hole (21); and the outer wall of the retreat prevention section (32) protrudes from the fixed section (31).

9. An inflatable restraint according to claim 1, wherein, The free end of the retreat prevention piece one (3-1) and the through hole (21) have a gap one (23).

10. The inflatable restraint according to claim 1, wherein, The circumferential side wall of the retreat prevention piece one (3-1) and the through hole (21) have a gap two (24).

11. An inflatable restraint according to claim 1, wherein, The outer wall of the expansion fixing sleeve (100) is provided with a rough surface.

12. An inflatable fixing sleeve according to claim 11, wherein The rough surface is formed by: The outer wall of the expansion fixing sleeve (100) is provided with a plurality of annular grooves, or the outer wall of the expansion fixing sleeve (100) is provided with a threaded surface or a checkered surface.

13. A hidden connector, characterized by: The connecting rod (200) and the expansion fixing sleeve (100) according to any one of claims 1-12 are included. The connecting rod (200) includes a threaded fixing section (202) and an insertion connecting section (201), the threaded fixing section (202) is inserted into the hole of another component to be connected in use, the outer wall of the insertion connecting section (201) is provided with a locking member (203) matched with the first retreat prevention piece (3-1); the insertion connecting section (201) is used for inserting the expansion fixing sleeve (100) and pushing the expansion member (4) to axially displace.

14. The concealed connector of claim 13, wherein: The inner wall of the connecting section (2) is provided with a limiting block (22), the outer wall of the expansion member (4) is provided with a protrusion (41), the limiting block (22) and the protrusion (41) have an overlapping part in the radial direction to realize the blocking and limiting of the limiting block (22) to the protrusion (41).

15. The concealed connector of claim 13, wherein: The locking member (203) includes a reverse thread, a thread, a pineapple thread, an annular protrusion or a bump.

16. The concealed connector according to any one of claims 13-15, wherein: The outer wall of the locking member (203) protrudes from the outer wall of the insertion connecting section (201).

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