Nickel-titanium alloy sliding cover, preparation method of nickel-titanium alloy sliding cover and self-ligating bracket

Abstract

The invention relates to a nickel-titanium alloy sliding cover and a preparation method thereof and a self-ligating bracket, the nickel-titanium alloy sliding cover comprises a sliding sheet, a connecting sheet and a clamping sheet which are connected in sequence, the sliding sheet, the connecting sheet and the clamping sheet are connected to form a sheet-shaped structure with a U-shaped rotary section, a limiting protrusion is formed on the side, close to the clamping sheet, of the sliding sheet in a protruding mode, and the limiting protrusion is connected with the clamping sheet. The nickel-titanium alloy sliding cover is made of nickel-titanium alloy. The nickel-titanium alloy sliding cover is made of nickel-titanium alloy, and the nickel-titanium alloy has hyperelasticity, a shape memory effect and good biocompatibility and is not prone to deformation in orthodontic treatment. In addition, a limiting protrusion is formed on the face, close to the clamping piece, of the sliding piece in a protruding mode, compared with a traditional mode of adopting an elastic arm, the limiting mode of the limiting protrusion is better in structural reliability, the pressure of an orthodontic wire and the external force applied to the sliding cover by a patient can be well borne, deformation is not prone to occurring in the treatment process, and the service life of the sliding cover is prolonged. And the structural stability is further ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of orthodontic instruments, and particularly to a nickel-titanium alloy sliding cover, a preparation method thereof, and a self-locking bracket. Background Art

[0002] Orthodontic treatment is a highly specialized branch discipline in the dental field, mainly for correcting tooth, jaw, and facial deformities, and gradually restoring the normal occlusal function of patients by fixing orthodontic appliances inside the oral cavity. Brackets are an important part of orthodontic appliances, mainly bonded to anterior teeth, canines, and premolars. Orthodontic treatment guides misaligned teeth to move to the ideal position by installing orthodontic wires in the slot grooves of the brackets. Traditional brackets use ligature wires or elastic rubber bands to fix the orthodontic arch wire in the slot groove, but this fixing method has disadvantages such as time-consuming and inconvenient clinical operation, large friction, and poor comfort. In recent years, the emergence of self-locking bracket correction systems has introduced new methods for the orthodontic treatment of malocclusions.

[0003] The biggest feature of self-locking brackets is that the self-locking structure of the brackets replaces the traditional ligature wire (loop) to ligate the orthodontic wire, reducing the friction inside the orthodontic appliance and significantly increasing the treatment efficiency. It is a fast, comfortable, and safe fixed correction device. The self-locking structure is usually added to the sliding cover of the traditional bracket, and the orthodontic wire is fixed in the slot groove. During orthodontic treatment, the sliding cover of the self-locking bracket bears the pressure of the orthodontic wire and the external force applied by the patient on the sliding cover. Traditional sliding covers are mostly made of stainless steel, with insufficient fatigue resistance and prone to deformation during treatment.

[0004] Document CN103340691A discloses a self-locking bracket with an anti-displacement sliding cover. The sliding cover used is an integral structure, integrally formed by elastic metal. The elastic metal includes nickel-titanium shape memory alloy, nickel-titanium-based shape memory alloy, titanium-based alloy, cobalt-chromium alloy, etc. The sliding cover used is a sheet-like structure with a U-shaped cross-section in rotation, including a sliding piece for sliding in the slideway, a card that can be inserted into the card slot at the end, and a connecting piece connecting the sliding piece and the card. The sliding piece and the card are respectively located on the two arms of the U. The sliding piece includes two elastic arms, and the outer edges of the two elastic arms are in interference fit with the inner wall of the slideway, so that the sliding piece can only slide forward or backward under the action of an external force. When the external force disappears, the sliding piece is fixed at the current position in the slideway. However, although the above sliding piece can improve the fatigue resistance by using nickel-titanium metal, the locking structure of the sliding cover depends on the two elastic arms at the front end of the sliding cover, and the structure of the elastic arms is still prone to deformation, thus affecting the treatment experience. Summary of the Invention

[0005] Based on this, it is necessary to provide a nickel-titanium alloy sliding cover that is not easily deformed, has super elasticity, good shape memory effect, and good biocompatibility, as well as a preparation method thereof and a self-locking bracket.

[0006] In a first aspect, the present application provides a nickel-titanium alloy sliding cover, including a sliding piece, a connecting piece, and a card connected in sequence. The sliding piece, the connecting piece, and the card are connected to form a sheet-like structure with a U-shaped cross-section in rotation. It is characterized in that a limiting protrusion is convexly formed on one side of the sliding piece close to the card, and the material of the nickel-titanium alloy sliding cover is nickel-titanium alloy.

[0007] In one embodiment, the limiting protrusion is formed at the end of the sliding piece away from the connecting piece;

[0008] In one embodiment, the limiting protrusion is an arc-shaped limiting protrusion, and an arc-shaped groove is formed on the other side of the sliding piece;

[0009] In one embodiment, an operation hole is formed on the card.

[0010] In one embodiment, the thickness of the nickel-titanium alloy sliding cover is 0.15 - 0.50 mm;

[0011] In one embodiment, the overall width range of the nickel-titanium alloy sliding cover is 1.0 - 4.0 mm.

[0012] In one embodiment, the thickness of the nickel-titanium alloy sliding cover is 0.15 - 0.25 mm;

[0013] In one embodiment, the overall width range of the nickel-titanium alloy sliding cover is 1.5 - 3.0 mm.

[0014] In a second aspect, the present application provides a manufacturing method of a nickel-titanium alloy sliding cover. The nickel-titanium alloy sliding cover is the nickel-titanium alloy sliding cover described in any of the above embodiments. The manufacturing method includes the following steps:

[0015] Provide a nickel-titanium alloy rod or a nickel-titanium alloy sheet;

[0016] Process the nickel-titanium alloy rod or the nickel-titanium alloy sheet into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece, and a card;

[0017] Process an operation hole and a bayonet for clamping into a card slot of a self-locking bracket on the card;

[0018] Process a limiting protrusion on the sliding piece;

[0019] Perform surface treatment on the surface of the nickel-titanium alloy sliding cover. The surface treatment includes at least one of chemical treatment, polishing, and mechanical grinding treatment.

[0020] In one embodiment, the finish temperature of austenite transformation of the nickel-titanium alloy rod is not higher than 50 °C, and the diameter range of the nickel-titanium alloy rod is 3-15 mm; the cold deformation amount of the nickel-titanium alloy rod is 20-70%;

[0021] In one embodiment, the finish temperature of austenite transformation of the nickel-titanium alloy sheet is not higher than 50 °C, and the cold deformation amount of the nickel-titanium alloy sheet is 20-70%; the thickness of the nickel-titanium alloy sheet is 0.1-0.5 mm.

[0022] In one embodiment, the cold deformation amount of the nickel-titanium alloy rod is 30-50%; and / or, the cold deformation amount of the nickel-titanium alloy sheet is 30-50%; and / or, the thickness of the nickel-titanium alloy sheet is 0.1-0.25 mm.

[0023] In one embodiment, a wire cutting machine tool or a numerical control machine tool processing method is used to process the nickel-titanium alloy rod into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece and a card; or, a stamping process is used to process the nickel-titanium alloy sheet into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece and a card;

[0024] In one embodiment, a limiting protrusion is formed on the sliding piece by using a thermoforming process or a stamping process.

[0025] In a third aspect, the present application provides a self-locking bracket, including a bracket body and the nickel-titanium alloy sliding cover as described in any one of the above embodiments. The bracket body has a slideway and a clamping groove. The sliding piece is slidably installed in the slideway, and the end of the card away from the connecting piece is clamped and installed in the clamping groove.

[0026] In one embodiment, the self-locking bracket further includes a bottom plate, and the bottom plate is connected to the bracket body and is used to cover the slideway.

[0027] The above nickel-titanium alloy sliding cover is made of nickel-titanium alloy. Nickel-titanium alloy has superelasticity, shape memory effect and good biocompatibility, and is not easy to deform during orthodontic treatment. Moreover, in the present application, a limiting protrusion is convexly formed on the surface of the sliding piece close to the card. Compared with the traditional method using elastic arms, the limiting method of the limiting protrusion has better structural reliability, can better withstand the pressure of the orthodontic wire and the external force applied by the patient on the sliding cover, is not easy to deform during the treatment process, and further ensures the structural stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0029] Figure 2 Structural schematic diagram of a self-locking bracket according to an embodiment of the present application;

[0030] Figure 3 Structural schematic diagram of a self-locking bracket according to an embodiment of the present application;

[0031] Figure 4 Exploded view of the structure according to an embodiment of the present application;

[0032] Figure 5a Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0033] Figure 5b Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0034] Figure 6a Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0035] Figure 6b Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0036] Figure 6c Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0037] Figure 7 Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0038] Figure 8 Structural schematic diagram of a self-locking bracket according to an embodiment of the present application;

[0039] Figure 9 Structural schematic diagram of a self-locking bracket according to an embodiment of the present application;

[0040] Figure 10a Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0041] Figure 10b Intermediate state structural schematic diagram of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0042] Figure 10cSchematic diagram of the intermediate state structure of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application;

[0043] Figure 11 Schematic diagram of the intermediate state structure of a nickel-titanium alloy sliding cover in the manufacturing process of the manufacturing method of a nickel-titanium alloy sliding cover according to an embodiment of the present application. Detailed implementation manners

[0044] To facilitate the understanding of the present invention, in order to make the above-mentioned objects, features, and advantages of the present invention more obvious and understandable, the following will describe the detailed implementation manners of the present invention in conjunction with the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention, and the preferred embodiments of the present invention are given in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. The present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0045] In a first aspect, please refer to Figure 1 , the present application provides a nickel-titanium alloy sliding cover 10, including a sliding piece 11, a connecting piece 12, and a card 13 connected in sequence. The sliding piece 11, the connecting piece 12, and the card 13 are connected to form a sheet-like structure with a U-shaped cross-section in rotation. A limiting protrusion 111 is convexly provided on one surface of the sliding piece 11 close to the card 13. The limiting protrusion 111 of the present application serves as a locking and limiting device for the sliding cover and plays a role of limiting and locking when cooperating with a self-locking bracket. In the present application, the material of the nickel-titanium alloy sliding cover is nickel-titanium alloy. In this way, the material is nickel-titanium alloy, and nickel-titanium alloy has superelasticity, shape memory effect, and good biocompatibility, and is not easily deformed during orthodontic treatment. Moreover, in the present application, a limiting protrusion is convexly provided on one surface of the sliding piece close to the card. The limiting method of the limiting protrusion is more reliable than the traditional method using an elastic arm. The limiting protrusion structure can better withstand the pressure of the orthodontic wire and the external force applied by the patient on the sliding cover, and is not easily deformed during the treatment process, further ensuring the structural stability.

[0046] In one embodiment, the limiting protrusion 111 is formed at the end of the sliding piece 11 away from the connecting piece 12; in this way, a better limiting and locking effect can be achieved. For example, the limiting protrusion 111 is an arc-shaped limiting protrusion, and an arc-shaped groove 112 is formed on the other side of the sliding piece 11; in this way, it can be formed by stamping process, and the processing process is simple and convenient.

[0047] In one embodiment, an operation hole is formed in the card 13. In this way, during orthodontic treatment, the doctor uses a probe or other tool to enter the hole to open the sliding cover of the self-locking bracket. For example, the operation hole has a circular cross-section.

[0048] In one embodiment, the thickness of the nickel-titanium alloy sliding cover is 0.15 - 0.50 mm; for example, the overall width range of the nickel-titanium alloy sliding cover is 1.0 - 4.0 mm. For example, the thickness of the nickel-titanium alloy sliding cover is 0.15 - 0.25 mm; for example, the overall width range of the nickel-titanium alloy sliding cover is 1.5 - 3.0 mm. In this way, the structural firmness is better.

[0049] In a second aspect, the present application provides a self-locking bracket. Please refer to Figures 2 to 4 and combine with Figure 1 , the self-locking bracket includes a bracket body 20 and the nickel-titanium alloy sliding cover 10 as described in any one of the above embodiments. The bracket body 20 has a slideway 21 and a clamping groove 22. The sliding piece 11 is slidably installed in the slideway 21, and the end of the card 13 away from the connecting piece 12 is clamped and installed in the clamping groove 22. For example, the bracket body 20 further has a placement groove 23 for placing the orthodontic wire. When the card is clamped and installed in the clamping groove, the placement groove is blocked to ensure the fixation of the orthodontic wire. Among them, Figure 2 is a schematic diagram of the nickel-titanium alloy sliding cover 10 of the self-locking bracket when it is not locked, Figure 3 is a schematic diagram of the nickel-titanium alloy sliding cover 10 of the self-locking bracket when it is locked, Figure 4 is an exploded view of the self-locking bracket. For example, the self-locking bracket further includes a bottom plate 30. The bottom plate 30 is connected to the bracket body 20 and is used to cover the slideway 21. In specific applications, the nickel-titanium alloy sliding cover 10 can be first installed on the bracket body 20, and then the bottom plate is welded and installed on the bracket body 20. During orthodontic treatment, the doctor uses a probe or other tool to enter the hole of the operation hole to open the sliding cover.

[0050] In a third aspect, the present application provides a manufacturing method of a nickel-titanium alloy sliding cover. The nickel-titanium alloy sliding cover is the nickel-titanium alloy sliding cover as described in any one of the above embodiments. The manufacturing method includes the following steps: "

[0051] Provide a nickel-titanium alloy rod or a nickel-titanium alloy sheet;

[0052] Process the nickel-titanium alloy bar or nickel-titanium alloy sheet into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece, and a card.

[0053] Process an operation hole and a bayonet for clamping into the clamping groove of the self-locking bracket on the card.

[0054] Process a limit protrusion on the sliding piece.

[0055] Perform surface treatment on the surface of the nickel-titanium alloy sliding cover, and the surface treatment includes at least one of chemical treatment, polishing, and mechanical grinding treatment.

[0056] In one embodiment, the end temperature of austenite transformation of the nickel-titanium alloy bar is not higher than 50 °C, and the diameter range of the nickel-titanium alloy bar is 3 - 15 mm; the cold deformation amount of the nickel-titanium alloy bar is 20 - 70%; for example, the end temperature of austenite transformation of the nickel-titanium alloy sheet is not higher than 50 °C, and the cold deformation amount of the nickel-titanium alloy sheet is 20 - 70%; the thickness of the nickel-titanium alloy sheet is 0.1 - 0.5 mm. For example, the cold deformation amount of the nickel-titanium alloy bar is 30 - 50%; and / or, the cold deformation amount of the nickel-titanium alloy sheet is 30 - 50%; and / or, the thickness of the nickel-titanium alloy sheet is 0.1 - 0.25 mm. In this way, it can ensure that the nickel-titanium alloy bar / sheet has good superelasticity and can meet the requirement of the sliding cover opening and closing repeatedly in the oral environment without deformation. By using the above nickel-titanium alloy bar or nickel-titanium alloy sheet, it further ensures that the nickel-titanium alloy has superelasticity and shape memory effect and is not easily deformed during orthodontic treatment.

[0057] In one embodiment, use a wire cutting machine or a numerical control machine tool processing method to process the nickel-titanium alloy bar into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece, and a card; or, use a stamping process to process the nickel-titanium alloy sheet into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece, and a card; for example, use a thermoforming process or a stamping process to process a limit protrusion on the sliding piece. In one embodiment, after processing the limit protrusion, perform a heat treatment operation on the whole nickel-titanium alloy sliding cover, and the temperature range of the sliding cover heat treatment is 250 - 750 °C, preferably 400 - 580 °C, and the heat treatment time is 2 minutes - 100 hours. After heat treatment, a protrusion is processed on the lower layer of the sliding cover, and the sliding cover has good elasticity and fatigue resistance.

[0058] The following separately introduces the process of making a nickel-titanium alloy sliding cover in two cases of nickel-titanium alloy bar and nickel-titanium alloy sheet and installing it on the bracket body to form a self-locking bracket.

[0059] In one embodiment, a method for manufacturing a nickel-titanium alloy sliding cover using a nickel-titanium alloy rod and a method for installing the nickel-titanium alloy sliding cover on a bracket body to form a self-locking bracket include the following steps:

[0060] 1. Select a nickel-titanium alloy rod or block with appropriate dimensions, appropriate austenite transformation end temperature, and mechanical properties to ensure that the nickel-titanium alloy rod has good superelasticity and can meet the requirements of repeated opening and closing of the sliding cover in the oral environment without deformation. The diameter range of the nickel-titanium alloy rod is 3-15 mm, and the cross-sectional length of the nickel-titanium alloy block is 3-15 mm. The austenite transformation end temperature is not higher than 50 °C. The nickel-titanium alloy rod has good elasticity, and its cold deformation amount is 20-70%, preferably 30-50%. In this way, it can be ensured that the nickel-titanium alloy rod has good superelasticity and can meet the requirements of repeated opening and closing of the sliding cover in the oral environment without deformation.

[0061] 2. Forming process: Cut the selected nickel-titanium alloy rod into the length required for processing the sliding cover, and process it according to the processing drawing. The nickel-titanium alloy rod can be processed into the required basic shape by processing methods such as wire cutting forming machine tools and numerical control machine tools. The sliding cover is divided into upper and lower layers. The upper layer is a card, and the lower layer is a sliding piece. The connection between the card and the sliding piece is a connecting piece. The upper card is used to install the orthodontic wire in the groove of the bracket body, and the lower sliding piece is used to place it in the slideway of the orthodontic bracket body assembled with it. The thickness range of the sliding cover is 0.15-0.50 mm, preferably 0.15-0.25 mm; the overall width of the sliding cover is 1.0-4.0 mm, preferably 1.5-3.0 mm. The processed shape is as Figure 5a or Figure 5b shown.

[0062] 3. Fine processing: Process the sliding cover with the basic shape by means of a laser machine, numerical control wire cutting machine tool, numerical control machine tool, etc. Process holes (operation holes) on the upper card of the sliding cover. During orthodontic treatment, doctors can use a probe or other tools to enter the holes to open the sliding cover. Combining with the shape of the orthodontic bracket assembled with the sliding cover, the sliding cover is further processed into different shapes, such as Figure 6a , Figure 6b , Figure 6c shown, to cooperate with the corresponding structure of the card slot.

[0063] 4. Processing the locking structure: Place the sliding cover in the tooling, apply force to the end of the lower layer of the sliding cover, and through the method of heat treatment and shaping, process a protrusion at the front end of the sliding cover, which is the limit protrusion. This protrusion is higher than other parts of the lower layer of the sliding cover, and this protrusion serves as the locking and limiting device of the sliding cover. The heat treatment temperature range of the sliding cover is 250-750 °C, preferably 400-580 °C, and the heat treatment time is 2 minutes - 100 hours. After heat treatment, a protrusion is processed on the lower layer of the sliding cover, and the sliding cover has good elasticity and fatigue resistance. As Figure 7as shown

[0064] 5. Perform surface treatment on the sliding cover. The surface of the sliding cover can be treated to be bright and round by chemical treatment, polishing, or mechanical grinding.

[0065] 6. Combine the sliding cover with the main body of the orthodontic bracket. There is a slideway at the middle position of the lingual side of the main body of the orthodontic bracket. The width of the slideway is 1 - 2.5 mm, preferably 1.2 - 1.8 mm. The height of the slideway is 0.15 - 1.2 mm. The height of the slideway is higher than the non-protruding part of the lower layer of the sliding cover and lower than the protruding part at the front end of the lower layer of the sliding cover. The lower layer of the sliding cover is placed in the slideway of the main body of the orthodontic bracket, and the upper layer of the sliding cover is placed above the working wing in the gingival direction of the bracket and inserted into the card slot of the main body and covers the bracket slot groove.

[0066] 7. Assemble the base plate of the orthodontic bracket to the bracket main body by welding, as Figure 9 shown, which is a schematic diagram after the sliding cover is pulled open. When the sliding cover is in the closed state, the upper sliding cover covers the slot groove of the bracket. When it is necessary to insert or replace the orthodontic wire, pull the upper sliding cover in the occlusal direction. Both the upper and lower sliding covers move from the gingival direction to the occlusal direction. When the upper sliding cover no longer covers the slot groove after moving, the lower sliding cover reaches the edge of the slideway of the bracket body. Since the height of the slideway is lower than the protrusion of the lower layer of the sliding cover, the protrusion cannot pass through the slideway, so that the sliding cover cannot continue to move, as Figure 8 shown. Due to the limitation of the slideway, the bracket body above the sliding cover, and the base plate below the sliding cover on the sliding cover, it is ensured that the sliding cover will not break away from the slideway when the sliding cover is pulled open, and the moving distance of the upper sliding cover is restricted. The moving distance range of the sliding cover is 0.5 - 2 mm, preferably 0.7 - 1.0 mm.

[0067] In one embodiment, the method for manufacturing a nickel-titanium alloy sliding cover using a nickel-titanium alloy sheet and the method for installing the nickel-titanium alloy sliding cover on the bracket main body to form a self-locking bracket include the following steps:

[0068] 1. Select a nickel-titanium alloy sheet with appropriate thickness, finish temperature of austenite transformation, and mechanical properties to ensure good superelasticity and meet the requirement that the sliding cover can be repeatedly opened and closed in the oral environment without deformation. The thickness of the nickel-titanium alloy sheet is 0.1 - 0.5 mm, preferably 0.1 - 0.25 mm; the width range is 1 - 4 mm, preferably 1.5 - 2.0 mm. The finish temperature of austenite transformation of the nickel-titanium alloy sheet is not higher than 50 °C. The sheet has good elasticity, and the cold deformation amount of the bar is 20 - 70%, preferably 30 - 50%. In this way, it is ensured to have good superelasticity and meet the requirement that the sliding cover can be repeatedly opened and closed in the oral environment without deformation.

[0069] 2. Forming process: Using precision stamping process, according to the shape and size design of the sliding cover, the nickel-titanium alloy sheet is stamped into the basic shape of the sliding cover. The precision of the stamping die needs to be controlled within ±0.1 mm to ensure that the dimensional accuracy of the sliding cover meets the assembly standard of the self-locking bracket. The end for subsequent processing into the lower-layer sliding cover can form a protrusion during the stamping process (such as Figure 10a , Figure 10b , Figure 10c shown).

[0070] 3. Fine processing: Using heat treatment to shape the sliding cover processed into the basic form into the required bent form. The sliding cover is divided into upper and lower layers. The upper layer is a card, the lower layer is a sliding piece, and the connecting piece is located in the middle of the two. The upper-layer card is used to install the orthodontic wire in the slot of the bracket, and the lower-layer sliding piece is used to place it in the slideway of the orthodontic bracket assembled with it. The upper and lower layers of the cover plate are connected by the connecting piece. During the stamping process, if there is no protrusion at the end of the lower layer of the sliding cover, a protrusion is formed by applying external force and heat treatment during this heat treatment process, which is the limiting protrusion. The protrusion is higher than other parts of the lower layer of the sliding cover, and this protrusion serves as the locking and limiting device of the sliding cover. The shape of the sliding cover after shaping is as shown in Figure 11 shown. The temperature range of the heat treatment of the sliding cover is 250 - 750 °C, preferably 400 - 580 °C, and the heat treatment time is 2 minutes - 100 hours. After heat treatment, a protrusion is processed on the lower layer of the sliding cover, and the sliding cover has good elasticity and fatigue resistance.

[0071] 4. Surface treatment of the sliding cover can be carried out by chemical treatment, polishing, and mechanical grinding to make the surface of the sliding cover bright and round.

[0072] 5. Combine the sliding cover with the main body of the orthodontic bracket. There is a slideway in the middle position of the lingual side of the main body of the orthodontic bracket. The width of the slideway is 1 - 2.5 mm, preferably 1.2 - 1.8 mm. The height of the slideway is 0.15 - 1.2 mm. The height of the slideway is higher than the non-protruding part of the lower layer of the sliding cover and lower than the protruding part at the front end of the lower-layer sliding cover. The lower layer of the sliding cover is placed in the slideway of the orthodontic bracket, and the upper layer of the sliding cover is placed in the groove above the working wing in the gingival direction of the bracket and covers the bracket slot.

[0073] 6. Assemble the orthodontic bracket base plate with the bracket main body by welding, as shown in Figure 9 shown. When the sliding cover is in the closed state, the upper-layer sliding cover covers the slot of the bracket. When it is necessary to insert or replace the orthodontic wire, pull the upper-layer sliding cover towards the occlusal direction. Both the upper and lower-layer sliding covers move from the gingival direction to the occlusal direction. When the upper-layer sliding cover no longer covers the slot after moving, the lower-layer sliding cover reaches the edge of the slideway of the bracket body. Since the height of the slideway is lower than the protrusion of the lower layer of the sliding cover, the protrusion cannot pass through the slideway, so that the sliding cover cannot continue to move, as shown in Figure 8As shown. Due to the restrictions on the sliding cover by the slideway, the bracket body on the upper part of the sliding cover, and the bottom plate on the lower part of the sliding cover, it is ensured that the sliding cover will not disengage from the slideway when the sliding cover is pulled open, and the moving distance of the upper sliding cover is restricted. The moving distance range of the sliding cover is 0.5 - 2 mm, preferably 0.7 - 1.0 mm.

[0074] The above nickel-titanium alloy sliding cover, its preparation method and self-locking bracket, the material of the nickel-titanium alloy sliding cover is nickel-titanium alloy. Nickel-titanium alloy has superelasticity, shape memory effect and good biocompatibility, and is not easy to deform during orthodontic treatment. Moreover, in this application, a limiting protrusion is convexly formed on the side of the sliding piece close to the card. Compared with the traditional method using elastic arms, the limiting method of the limiting protrusion has better structural reliability, can better withstand the pressure of the orthodontic wire and the external force applied by the patient on the sliding cover, is not easy to deform during the treatment process, and further ensures the structural stability.

[0075] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification. It should be noted that the phrases "in one embodiment", "for example", "again for example", etc. in this application are intended to illustrate this application, rather than to limit this application.

[0076] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A nickel-titanium alloy sliding cover, comprising a sliding piece, a connecting piece and a card which are sequentially connected, wherein the sliding piece, the connecting piece and the card are connected to form a sheet-like structure with a U-shaped cross-section in rotation, and is characterized in that, On the side of the sliding piece close to the card, a limiting protrusion is convexly formed, and the nickel-titanium alloy sliding cover is made of nickel-titanium alloy.

2. The nickel-titanium alloy sliding cover according to claim 1, wherein The limiting protrusion is formed at the end of the sliding piece away from the connecting piece; And / or, the limiting protrusion is an arc-shaped limiting protrusion, and an arc-shaped groove is formed on the other side of the sliding piece; And / or, an operation hole is formed on the card.

3. The nickel-titanium alloy sliding cover according to claim 2, wherein, The thickness of the nickel-titanium alloy sliding cover is 0.15 - 0.50 mm; And / or, the overall width range of the nickel-titanium alloy sliding cover is 1.0 - 4.0 mm.

4. The nickel-titanium alloy sliding cover according to claim 3, wherein The thickness of the nickel-titanium alloy sliding cover is 0.15 - 0.25 mm; And / or, the overall width range of the nickel-titanium alloy sliding cover is 1.5 - 3.0 mm.

5. A manufacturing method of a nickel-titanium alloy sliding cover, characterized in that, The nickel-titanium alloy sliding cover is the nickel-titanium alloy sliding cover described in any one of claims 1 to 4, and the manufacturing method includes the following steps: Provide a nickel-titanium alloy rod or a nickel-titanium alloy sheet; Process the nickel-titanium alloy rod or the nickel-titanium alloy sheet into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece, and a card; Form an operation hole and a bayonet for a card slot for clamping a self-locking bracket on the card; Form a limiting protrusion on the sliding piece; Perform surface treatment on the surface of the nickel-titanium alloy sliding cover, and the surface treatment includes at least one of chemical treatment, polishing, and mechanical grinding treatment.

6. The manufacturing method according to claim 5, characterized in that, The end temperature of the austenite transformation of the nickel-titanium alloy rod is not higher than 50 °C, and the diameter range of the nickel-titanium alloy rod is 3 - 15 mm; the cold deformation amount of the nickel-titanium alloy rod is 20 - 70%; And / or, the end temperature of the austenite transformation of the nickel-titanium alloy sheet is not higher than 50 °C, and the cold deformation amount of the nickel-titanium alloy sheet is 20 - 70%; the thickness of the nickel-titanium alloy sheet is 0.1 - 0.5 mm.

7. The manufacturing method according to claim 5, wherein The cold deformation amount of the nickel-titanium alloy rod is 30 - 50%; and / or, the cold deformation amount of the nickel-titanium alloy sheet is 30 - 50%; and / or, the thickness of the nickel-titanium alloy sheet is 0.1 - 0.25 mm.

8. The manufacturing method according to claim 5, wherein, Use a wire cutting machine tool or a numerical control machine tool processing method to process the nickel-titanium alloy rod into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece, and a card; or, use a stamping process to process the nickel-titanium alloy sheet into a sheet-like structure with a U-shaped cross-section formed by a sliding piece, a connecting piece, and a card; And / or, use a thermoforming process or a stamping process to form a limiting protrusion on the sliding piece; And / or, after forming the limiting protrusion, perform a heat treatment operation on the whole nickel-titanium alloy sliding cover, and the temperature range of the heat treatment operation is 250 °C - 750 °C, preferably 400 °C - 580 °C, and the heat treatment time is 2 minutes - 100 hours.

9. A self-locking bracket, characterized in that, It includes a bracket body and the nickel-titanium alloy sliding cover described in any one of claims 1 to 8, the bracket body has a slideway and a card slot, the sliding piece is slidably installed in the slideway, and the end of the card away from the connecting piece is clamped and installed in the card slot.

10. The self-locking bracket according to claim 9, wherein The self-locking bracket further includes a bottom plate, and the bottom plate connects the bracket body and is used to cover the slideway; And / or, the width of the slideway is 1 - 2.5 mm, and the height of the slideway is 0.15 - 1.2 mm.

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