Hidden inward-opening and inward-reversing hinge suitable for 180-degree opening of U-shaped door and window hardware notch

Abstract

The invention discloses an invisible inward-opening and inward-reversing hinge suitable for 180-degree opening of a U-shaped door and window hardware notch. The invisible inward-opening and inward-reversing hinge comprises an upper hinge body and a lower hinge body. An upper fixing plate; one end of the upper connecting rod is connected with an extension plate; a first limiting groove is formed in the bottom of the upper positioning plate; the first sliding rod is arranged between the upper connecting rod and the upper fixing plate, and a first adjusting fixing piece is arranged on one side of the first sliding rod; a lower fixing plate; a connecting cylinder is arranged on the outer side of the bearing corner; installing a cushion block; and the second connecting block is arranged between the lower fixing plate and the bearing corner. Through the matched combination design of the upper hinge and the lower hinge, 180-degree large-angle stable opening of the door and window sash is stably achieved, the core requirements for ventilation and cleaning of the door and window in the large-opening state are met, meanwhile, the door and window sash can be directly matched with a universal standard U-shaped notch profile, additional milling machining and modification of the profile are not needed, and the cost is reduced. And the application range and the global market suitability of the product are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of door and window hardware accessories, and in particular to a concealed inward opening and tilting hinge suitable for U-shaped door and window hardware slots that open 180 degrees. Background Technology

[0002] With the continuous improvement of building energy conservation and home comfort requirements, inward-opening and tilt-and-turn windows have been widely used in residential and commercial buildings due to their core advantages such as high ventilation and safety, small indoor space occupation, and convenient cleaning and maintenance. The U-shaped groove, as a universal standard groove structure for door and window profiles, is currently the most widely used profile matching structure in door and window systems. The inward-opening and tilt-and-turn hinge hardware that matches it is the core component determining the opening performance, sealing performance, and load-bearing safety performance of doors and windows.

[0003] Currently, for U-shaped slot doors and windows, the industry mainly focuses on inward-opening and tilt-and-turn hinges with small-angle opening structures. Hardware systems that can achieve a 180-degree large-angle opening have significant technical shortcomings in the international market. For example, existing 180-degree opening hinge products have unreasonable opening trajectory designs, which easily lead to component interference and jamming during opening and closing. Repeated opening and closing results in severe component wear, directly affecting the product's service life and opening smoothness. They are also difficult to meet the needs of different usage scenarios and mostly require additional custom production. Summary of the Invention

[0004] This invention provides a concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots. Through the matching combination design of upper hinge 1 and lower hinge 2, it can stably achieve a large-angle and smooth 180-degree opening of the door and window sash, which not only meets the core needs of ventilation and cleaning when the door and window are fully open, but also can be directly adapted to universal standard U-shaped slot profiles without the need for additional milling and modification of the profiles, greatly improving the product's applicability and global market adaptability.

[0005] To solve the above-mentioned technical problems, the present invention provides a concealed inward opening and tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots, comprising: An upper hinge and a lower hinge; the upper hinge includes an upper fixed plate, an upper connecting rod, an upper positioning plate and a first sliding rod, and the lower hinge includes a lower fixed plate, a load-bearing corner, a mounting pad and a second connecting block; The upper fixing plate is provided with a first through groove and a second through groove, and a first slider is slidably provided inside the first through groove; An upper connecting rod is connected to an extension plate at one end, and a first connecting plate and a second connecting plate are provided on the surface of the upper connecting rod. The upper positioning plate has a first limiting groove at the bottom; A first sliding rod is disposed between the upper connecting rod and the upper fixed plate, and a first adjusting and fixing piece is provided on one side of the first sliding rod; The lower fixing plate is provided with a third through groove and a fourth through groove; The load-bearing corner is equipped with a connecting cylinder on the outside, and a positioning column is provided inside the connecting cylinder. Mounting pads are provided at the bottom of the lower fixing plate; The second connecting block is disposed between the lower fixed plate and the load-bearing corner, and the top of the second connecting block is provided with a third connecting plate.

[0006] As a preferred embodiment of the above technical solution, the upper fixing plate is L-shaped, and a movable groove is provided through the side of the upper fixing plate. One end of the upper connecting rod is provided with a protruding limiting block, and the protruding limiting block is slidably disposed inside the movable groove.

[0007] As a preferred embodiment of the above technical solution, the extension plate and the first connecting plate are fitted together, the bottom surface of the upper positioning plate is provided with a first limiting groove, the extension plate is slidably disposed inside the first limiting groove, and a connecting shaft is provided through the extension plate and its end is matched and connected to the upper positioning plate.

[0008] As a preferred embodiment of the above technical solution, a positioning rod is provided through the surface of the first slide rod, and the positioning rod passes through the upper connecting rod, the extension plate, and the first slide rod in sequence to match and connect with the first slider. An adjusting screw is provided through the surface of the first adjusting fixing plate, and the adjusting screw passes through the upper connecting rod, the first connecting plate, and the first adjusting fixing plate in sequence to match and connect with the upper fixing plate.

[0009] As a preferred embodiment of the above technical solution, a second slider is slidably provided inside the third through groove, and a second adjusting and fixing piece is provided on the surface of the fourth through groove.

[0010] As a preferred embodiment of the above technical solution, both the load-bearing corner and the surface of the upper positioning plate are provided with installation interfaces, and one end of the bottom of the positioning column passes through the third connecting plate and the second connecting block and is connected to the lower fixing plate.

[0011] As a preferred embodiment of the above technical solution, a side pad is provided on the outer side of the mounting pad, the lower fixing plate is provided on the inner side of the side pad, and a connecting bend is provided between the side pad and the mounting pad.

[0012] As a preferred embodiment of the above technical solution, the bottom of the second connecting block is provided with a second limiting groove, the second connecting block is provided with a second sliding rod through the inside and the second sliding rod passes through the second limiting groove and is matched and connected with the second slider, and the second adjusting fixing piece is provided with an adjusting screw through and is matched and connected with the lower fixing plate.

[0013] As a preferred embodiment of the above technical solution, the top of the third connecting plate is provided with a connecting piece, a locking post is provided through the inside of the load-bearing corner, one end of the bottom of the locking post is provided through the load-bearing corner and matched with the connecting piece, and a fourth connecting plate is provided between the second connecting block and the third connecting plate.

[0014] This invention provides a concealed inward-opening and inward-tilting hinge suitable for U-shaped door and window hardware openings. It comprises an upper fixed plate, an upper connecting rod, an upper positioning plate, a first sliding rod, a lower fixed plate, a load-bearing corner, and a second connecting block. Through the sliding limit cooperation between the movable groove of the upper fixed plate and the protruding limiting block of the upper connecting rod, the linkage cooperation between the first slider and the first sliding rod in the first through groove, and the transmission cooperation between the second slider and the second connecting block in the third through groove of the lower fixed plate, the movement path of the door and window sash is precisely constrained throughout the entire opening and closing process. There is no interference from any components or any jamming or obstruction throughout the entire process, ensuring smooth opening and closing. The smooth operation significantly reduces component friction and extends product lifespan. Simultaneously, the fully concealed structural design hides all components within the profile grooves after installation, ensuring a clean and seamless overall appearance for the doors and windows. This perfectly complements the aesthetic requirements of high-end doors and windows. The matching design of the first and second adjusting plates allows for precise micro-adjustments in multiple directions and dimensions, adapting to U-groove door and window profiles of varying wall thicknesses and specifications. This solves the pain points of traditional hardware, such as narrow compatibility and low tolerance for errors, and can cover a wide range of applications. The installation requirements of most standard U-groove door and window systems on the market are significantly reduced, greatly simplifying installation and after-sales adjustments. This effectively improves on-site installation efficiency and profile compatibility. Both the upper and lower hinges adopt an integrated rigid load-bearing structure. The upper positioning plate and load-bearing corner are equipped with dedicated installation interfaces, enabling high-strength and stable connections with door and window sashes and frames. Combined with multiple sets of limiting sliding structures and coaxial connection positioning structures, the overall load-bearing capacity and structural rigidity are effectively improved, resisting structural deformation and displacement risks under strong wind pressure. At the same time, the precise motion trajectory design ensures uniform compression and reset of the sealing strip during the opening and closing of the door and window sash. It can maintain stable sealing performance even after long-term repeated use, fundamentally avoiding problems such as sealing failure, air leakage, and water seepage. The hinge provided by this invention, through the matching combination design of the upper and lower hinges, stably achieves a smooth 180-degree large-angle opening of the door and window sash. This not only meets the core needs of ventilation and cleaning when the door and window are fully open, but also directly adapts to universal standard U-groove profiles without the need for additional milling modifications to the profiles, greatly improving the product's applicability and global market compatibility.

[0015] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is an exploded view of the upper hinge of the present invention; Figure 3 This is a bottom view of the upper hinge of the present invention; Figure 4 This is an exploded view of the lower hinge of the present invention.

[0017] In the diagram: 1 Upper hinge, 2 Lower hinge, 3 Upper fixed plate, 31 First through groove, 311 First slider, 32 Second through groove, 33 Movable groove, 4 Upper connecting rod, 41 Extension plate, 411 Connecting shaft, 42 First connecting plate, 43 Second connecting plate, 44 Protruding limiting block, 5 Upper positioning plate, 51 First limiting groove, 6 First sliding rod, 61 Positioning rod, 62 First adjusting fixing piece, 7 Lower fixed plate, 71 Third through groove, 711 Second slider, 72 Fourth through groove, 721 Second adjusting fixing piece, 8 Load-bearing corner, 81 Connecting cylinder, 82 Positioning post, 9 Mounting pad, 91 Side pad, 92 Connecting bend, 10 Second connecting block, 101 Third connecting plate, 102 Second limiting groove, 103 Connecting piece, 104 Fourth connecting plate, 105 Locking post. Detailed Implementation

[0018] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0019] See Figure 1-4 This invention provides a concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots, comprising: Upper hinge 1 and lower hinge 2; upper hinge 1 includes upper fixed plate 3, upper connecting rod 4, upper positioning plate 5 and first sliding rod 6, and lower hinge 2 includes lower fixed plate 7, load-bearing corner 8, mounting pad 9 and second connecting block 10. The upper fixed plate 3 is provided with a first through groove 31 and a second through groove 32, and a first slider 311 is slidably provided inside the first through groove 31. The upper connecting rod 4 has an extension plate 41 connected to one end, and a first connecting plate 42 and a second connecting plate 43 are provided on the surface of the upper connecting rod 4. The upper positioning plate 5 has a first limiting groove 51 at the bottom; The first slide rod 6 is disposed between the upper connecting rod 4 and the upper fixed plate 3, and a first adjusting and fixing piece 62 is provided on one side of the first slide rod 6; The lower fixing plate 7 is provided with a third through groove 71 and a fourth through groove 72; The load-bearing corner is 8, with a connecting cylinder 81 on the outside and a positioning post 82 inside the connecting cylinder 81. Mounting pad 9 is placed at the bottom of the lower fixing plate 7; The second connecting block 10 is located between the lower fixed plate 7 and the load-bearing corner 8, and the top of the second connecting block 10 is provided with a third connecting plate 101.

[0020] This embodiment provides a concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots. It comprises an upper fixed plate 3, an upper connecting rod 4, an upper positioning plate 5, a first sliding rod 6, a lower fixed plate 7, a load-bearing corner 8, and a second connecting block 10. Through the sliding limit cooperation between the movable groove 33 of the upper fixed plate 3 and the protruding limiting block 44 of the upper connecting rod 4, the linkage cooperation between the first slider 311 in the first through groove 31 and the first sliding rod 6, and the transmission cooperation between the second slider 711 in the third through groove 71 of the lower fixed plate 7 and the second connecting block 10, the movement path of the entire opening and closing process of the door and window sash is precisely constrained. The entire process is free of component interference and jamming, ensuring smooth and stable opening and closing, significantly reducing component friction wear and extending product lifespan. Simultaneously, the overall design employs a fully concealed structure, with all components hidden within the profile grooves after installation, ensuring a clean and complete overall appearance for the doors and windows. This perfectly matches the aesthetic requirements of high-end doors and windows. Through the matching structure of the first adjusting fixing plate 62 and the second adjusting fixing plate 721, precise micro-adjustments in multiple directions and dimensions can be achieved, adapting to U-groove door and window profiles of different wall thicknesses and specifications, solving the compatibility issues of traditional hardware. Addressing the pain points of narrow range and low error tolerance, this system covers the installation needs of most standard U-groove door and window systems on the market, significantly reducing the difficulty of installation and after-sales adjustment, effectively improving on-site installation efficiency and profile compatibility. Both the upper hinge 1 and lower hinge 2 adopt an integrated rigid load-bearing structure. The upper positioning plate 5 and load-bearing corner 8 are equipped with dedicated installation interfaces, enabling high-strength and stable connections with door and window sashes and frames. Combined with multiple sets of limiting sliding structures and coaxial connection positioning structures, it effectively improves overall load-bearing capacity and structural rigidity, resisting structural deformation and displacement risks under strong wind pressure scenarios; simultaneously, it provides precise operation... The dynamic trajectory design ensures uniform compression and repositioning of the sealing strip during the opening and closing of doors and windows, maintaining stable sealing performance even after long-term repeated use. This fundamentally avoids problems such as seal failure, air leakage, and water seepage. The hinge provided by this invention, through the matching combination design of upper hinge 1 and lower hinge 2, stably enables smooth opening of doors and windows at a large angle of 180 degrees. This not only meets the core needs of ventilation and cleaning when doors and windows are fully open, but also directly adapts to universal standard U-shaped groove profiles without the need for additional milling modifications to the profiles, greatly improving the product's applicability and global market adaptability.

[0021] In a further embodiment of this invention, the upper fixing plate 3 is L-shaped, and a movable groove 33 is provided through the side of the upper fixing plate 3. One end of the upper connecting rod 4 is provided with a protruding limiting block 44, which is slidably disposed inside the movable groove 33.

[0022] In this embodiment, the movable groove 33 of the upper fixed plate 3 and the protruding limiting block 44 of the upper connecting rod 4 slide and limit each other, and the first slider 311 in the first through groove 31 and the first sliding rod 6 work together to precisely constrain the movement path of the door and window sash throughout the opening and closing process. There is no interference from parts or jamming or obstruction throughout the process, and the opening and closing is smooth and stable, which greatly reduces the friction wear of parts and extends the service life of the product.

[0023] In a further embodiment of this invention, the extension plate 41 and the first connecting plate 42 are fitted together, the bottom surface of the upper positioning plate 5 is provided with a first limiting groove 51, the extension plate 41 is slidably disposed inside the first limiting groove 51, and a connecting shaft 411 is provided through the extension plate 41 and its end is matched and connected to the upper positioning plate 5.

[0024] In this embodiment, the extension plate 4 is locked inside the connecting shaft 411 to limit the position of the extension plate, and at the same time, it can limit the position of the entire upper connecting rod 4.

[0025] In a further embodiment of this invention, a positioning rod 61 is provided through the surface of the first slide rod 6. The positioning rod 61 passes through the upper connecting rod 4, the extension plate 41, the first slide rod 6 and is matched and connected to the first slider 311. An adjusting screw is provided through the surface of the first adjusting fixing piece 62. The adjusting screw passes through the upper connecting rod 4, the first connecting plate 42, the first adjusting fixing piece 62 and is matched and connected to the upper fixing plate 3.

[0026] In this embodiment, the linkage between the first slider 311 and the first slide rod 6 in the first through groove 31 can precisely constrain the movement path of the entire opening and closing process of the door and window sash. The whole adopts a fully concealed structure design. After installation, all components are hidden inside the profile groove, with no exposed structure, ensuring the simplicity and integrity of the overall appearance of the door and window.

[0027] In a further embodiment of this invention, a second slider 711 is slidably provided inside the third through groove 71, and a second adjusting and fixing piece 721 is provided on the surface of the fourth through groove 72.

[0028] The matching structure design of the first adjusting fixing piece 62 and the second adjusting fixing piece 721 in this embodiment can realize precise micro-adjustment in multiple directions and dimensions, adapt to U-shaped groove door and window profiles with different wall thicknesses and specifications, and solve the pain points of narrow compatibility and low fault tolerance of traditional hardware.

[0029] In a further embodiment of this invention, both the load-bearing corner 8 and the upper positioning plate 5 are provided with mounting interfaces, and one end of the bottom of the positioning column 82 passes through the third connecting plate 101 and the second connecting block 10 and connects to the lower fixing plate 7.

[0030] In this embodiment, the upper positioning plate 5 and the load-bearing corner 8 are equipped with dedicated installation interfaces, which can achieve a high-strength and stable connection with the door and window sash and frame. Combined with multiple sets of limiting sliding structures and coaxial connection positioning structures, the overall load-bearing capacity and structural rigidity are effectively improved, resisting the risk of structural deformation and displacement under strong wind pressure.

[0031] In a further embodiment of this invention, a side pad 91 is provided on the outer side of the mounting pad 9, and a lower fixing plate 7 is provided on the inner side of the side pad 91. A connecting bend 92 is provided between the side pad 91 and the mounting pad 9.

[0032] In this embodiment, the mounting pad 9 and side pad 91 can be adjusted and replaced according to installation and thickness requirements to meet different market demands.

[0033] In a further embodiment of this invention, the bottom of the second connecting block 10 is provided with a second limiting groove 102, the second connecting block 10 is provided with a second sliding rod through it and the second sliding rod passes through the second limiting groove 102 and is matched and connected with the second slider 711, and the second adjusting fixing piece 721 is provided with an adjusting screw through it and is matched and connected with the lower fixing plate 7.

[0034] The matching structural design of the first adjusting fixing piece 62 and the second adjusting fixing piece 721 in this embodiment can achieve precise micro-adjustment in multiple directions and dimensions, and adapt to U-shaped groove door and window profiles with different wall thicknesses and specifications.

[0035] In a further embodiment of this invention, the top of the third connecting plate 101 is provided with a connecting piece 103, the inside of the load-bearing corner 8 is provided with a locking post 105, one end of the bottom of the locking post 105 passes through the load-bearing corner 8 and is matched and connected with the connecting piece 103, and a fourth connecting plate 104 is provided between the second connecting block 10 and the third connecting plate 101.

[0036] In this embodiment, the upper positioning plate 5 and the load-bearing corner 8 are provided with dedicated installation interfaces, which can achieve a high-strength and stable connection with the door and window sash and frame. With the cooperation of multiple sets of limit sliding structures and coaxial connection positioning structures, the locking column 105 is positioned and locked again by the top of the connecting piece 103 to maintain the stability of the overall structure.

[0037] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0038] 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 at least one of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots, characterized in that, include: Upper hinge (1) and lower hinge (2); the upper hinge (1) includes an upper fixed plate (3), an upper connecting rod (4), an upper positioning plate (5) and a first sliding rod (6); the lower hinge (2) includes a lower fixed plate (7), a load-bearing corner (8), a mounting pad (9) and a second connecting block (10); The upper fixed plate (3) is provided with a first through groove (31) and a second through groove (32), and a first slider (311) is slidably provided inside the first through groove (31). The upper connecting rod (4) has an extension plate (41) connected to one end. The surface of the upper connecting rod (4) is provided with a first connecting plate (42) and a second connecting plate (43). The upper positioning plate (5) has a first limiting groove (51) at the bottom; The first slide rod (6) is located between the upper connecting rod (4) and the upper fixing plate (3), and a first adjusting fixing piece (62) is provided on one side of the first slide rod (6). The lower fixing plate (7) is provided with a third through groove (71) and a fourth through groove (72); The load-bearing corner (8) is provided with a connecting cylinder (81) on the outside, and a positioning column (82) is provided inside the connecting cylinder (81). Mounting pad (9) is set at the bottom of the lower fixing plate (7); The second connecting block (10) is located between the lower fixed plate (7) and the load-bearing corner (8), and the top of the second connecting block (10) is provided with a third connecting plate (101).

2. The concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware grooves according to claim 1, characterized in that, The upper fixing plate (3) is L-shaped, and a movable groove (33) is provided through the side of the upper fixing plate (3). One end of the upper connecting rod (4) is provided with a protruding limiting block (44), and the protruding limiting block (44) is slidably disposed inside the movable groove (33).

3. The concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware grooves according to claim 1, characterized in that, The extension plate (41) and the first connecting plate (42) are fitted together. The bottom surface of the upper positioning plate (5) is provided with a first limiting groove (51). The extension plate (41) is slidably disposed inside the first limiting groove (51). A connecting shaft (411) is provided through the extension plate (41) and its end is matched and connected to the upper positioning plate (5).

4. The concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware grooves according to claim 1, characterized in that, A positioning rod (61) is provided through the surface of the first slide rod (6). The positioning rod (61) passes through the upper connecting rod (4), the extension plate (41), and the first slide rod (6) in sequence and is matched and connected with the first slider (311). An adjusting screw is provided through the surface of the first adjusting fixing plate (62). The adjusting screw passes through the upper connecting rod (4), the first connecting plate (42), and the first adjusting fixing plate (62) in sequence and is matched and connected with the upper fixing plate (3).

5. A concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware grooves according to claim 1, characterized in that, The third through groove (71) is provided with a second slider (711) inside, and the surface of the fourth through groove (72) is provided with a second adjusting and fixing piece (721).

6. A concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots, as described in claim 1, is characterized in that... The load-bearing corner (8) and the upper positioning plate (5) are both provided with installation interfaces. One end of the bottom of the positioning column (82) passes through the third connecting plate (101) and the second connecting block (10) and is connected to the lower fixing plate (7).

7. A concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware grooves according to claim 1, characterized in that, The mounting pad (9) has a side pad (91) on its outer side, and the lower fixing plate (7) is located on the inner side of the side pad (91). A connecting bend (92) is provided between the side pad (91) and the mounting pad (9).

8. A concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots, as described in claim 1, is characterized in that... The second connecting block (10) has a second limiting groove (102) at the bottom. The second connecting block (10) has a second sliding rod that passes through it and is connected to the second slider (711) through the second limiting groove (102). The second adjusting fixing piece (721) has an adjusting screw that passes through it and is connected to the lower fixing plate (7).

9. A concealed inward-opening and inward-tilting hinge suitable for 180-degree opening of U-shaped door and window hardware slots, as described in claim 1, is characterized in that... The third connecting plate (101) is provided with a connecting piece (103) at the top, and a locking post (105) is provided inside the load-bearing corner (8). One end of the bottom of the locking post (105) passes through the load-bearing corner (8) and is matched and connected with the connecting piece (103). A fourth connecting plate (104) is provided between the second connecting block (10) and the third connecting plate (101).

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