Nut forming method based on spring type thread structure and nut

Abstract

The invention relates to the technical field of nut manufacturing, and particularly discloses a nut forming method based on a spring type thread structure and a nut The method comprises the steps that 10, the spring type thread structure is prefabricated, the spring type thread structure comprises a strip-shaped body extending spirally, and a thread tooth-shaped structure is prefabricated on the inner surface of the strip-shaped body; 20, the spring type thread structure is axially pressed and then kept in the pressed state, and the strip-shaped bodies of the adjacent circles are tightly attached; and 30, welding is conducted on the attaching gaps of the strip-shaped bodies of the adjacent circles, and the prefabricated spring type thread structures are welded to form nut structures. The nut produced through the nut forming method is high in precision, overall cutting machining is avoided, the material utilization rate is increased, the production cost is reduced, the application range is wider, and the nut forming method meets the manufacturing requirements of various nuts.

Description

Technical Field

[0001] The present invention relates to the technical field of nut manufacturing, and particularly relates to a nut forming method and a nut based on a spring-type thread structure. Background Art

[0002] In the existing fields of machining and fastener manufacturing, nuts are usually manufactured by machining methods such as threading or grinding threads. However, these traditional methods have the following problems: (1) Threading is of low efficiency and poor surface quality. The traditional turning process requires a long-shank tool to machine a long nut. The tool has insufficient rigidity and is prone to vibration, resulting in poor surface roughness of the thread. During the turning process, the thread accuracy is greatly affected by tool wear, making it difficult to ensure the lead accuracy.

[0003] (2) Thread grinding can improve the surface quality and accuracy, but the thread grinding efficiency is low, the cost is high, and it is difficult to grind long nuts, resulting in low output per unit time. Due to the limited length of the grinding wheel rod, it is easy to be restricted by space when grinding long nuts, and it is difficult to effectively grind the full thread. The grinding equipment is expensive and the maintenance cost is high, making the overall manufacturing cost remain high.

[0004] Based on the deficiencies of traditional nut processing, a manufacturing solution for manufacturing nuts in a split manner has emerged in the prior art. Generally, the thread structure and the housing structure are processed separately, and then the two are assembled into a complete nut by means of later physical connection or hot processing.

[0005] For example, Chinese Patent No. CN105127690A discloses a tool and method for machining an internal thread with an extra-large pitch. First, a steel plate strip with a corresponding cross-section is made according to the thread structure; then, the above steel plate strip is wound into a spiral steel plate strip thread; finally, the above steel plate strip thread is placed in the inner hole of the part and fixed in the inner hole of the part by welding, thereby forming a nut structure with an internal thread.

[0006] The above internal thread processing method disclosed in CN105127690A, although it can simplify the processing flow of the overall nut structure to a certain extent, has the following defects: (1) When machining nuts with a small radial dimension, especially slender lead screws, the internal welding space is limited. Since welding occurs in the narrow inner cavity of the nut, the welding angle and the accessibility of the welding torch are poor, making it difficult to ensure that each turn of the spring can be welded in place with the housing.

[0007] (2) The welding reliability is poor. The internal solder joints often concentrate in local areas, easily forming problems such as virtual welding, discontinuous welds or poor contact, which in turn affect the overall structural strength and load performance of the nut.

[0008] (3) Poor consistency. Due to limitations in welding operation techniques and positions, it is difficult to ensure the consistency of the finished products.

[0009] For another example, a method for manufacturing a nut tube disclosed in a Chinese invention patent with the publication number CN117283236A. First, a special threaded wire is wound into a spring nut with tightly adjacent turns in a spring shape. Then, a heat-melt tube or a plastic steel tube is lined on the outer ring of the spring nut to firmly integrate it with the spring nut, thereby forming the required nut tube.

[0010] The method for manufacturing the nut tube disclosed in the above CN117283236A changes the traditional manufacturing method of nuts and can be applied in some light-load and low-strength application scenarios. However, the above method for manufacturing the nut tube still has the following defects: (1) Limited structural strength: The plastic material itself has insufficient strength and is difficult to withstand high torque or high axial loads, and problems such as thread slipping and loosening are likely to occur during use.

[0011] (2) Poor thermal stability: In a high-temperature environment, the heat-melt tube or the plastic steel tube may undergo thermal deformation or aging, resulting in a decrease in connection reliability.

[0012] (3) It cannot be used for high-precision components. Due to differences in material ductility and elasticity, it is difficult to meet the high-precision requirements for overall coaxiality and dimensional stability.

[0013] In summary, the existing split-connected nut solutions generally have technical problems such as insufficient structural stability, poor welding reliability, or limited application scope. There is an urgent need for a new nut forming process that can ensure thread accuracy and achieve the unity of overall structural strength and manufacturing efficiency. Summary of the Invention

[0014] The technical problem to be solved by the present invention is to provide a nut forming method based on a spring-type thread structure, which directly welds a preformed spring-type thread structure into an integral nut structure in a compressed state to overcome various defects of traditional nut manufacturing based on turning threads and manufacturing nuts through a split structure.

[0015] To solve the above technical problem, the technical solution provided by the present invention is as follows: A nut forming method based on a spring-type thread structure, at least including the following steps: Step 10: Pre-manufacture a spring-type thread structure, where the spring-type thread structure includes a spiral-extending strip-shaped body, and a thread tooth profile structure is pre-manufactured on the inner surface of the strip-shaped body; Step 20: Axially compress and hold the spring-type thread structure in a compressed state, with the adjacent turns of the strip-shaped body closely fitting together; Step 30: Weld at the joint gap of the strip-shaped bodies in adjacent circles, and the prefabricated spring-type thread structure is formed into a nut structure by welding.

[0016] In a preferred embodiment, the thread profile structure is any one of trapezoidal thread, T-shaped thread, triangular thread, arc thread, and rectangular thread.

[0017] In a preferred embodiment, in Step 10, at least one side of the outer surface of the strip-shaped body is prefabricated with a welding groove surface; in Step 20, after the spring-type thread structure is axially pressed together, a welding groove is formed at the welding groove surface.

[0018] In a preferred embodiment, both sides of the outer surface of the strip-shaped body are prefabricated with welding groove surfaces.

[0019] In a preferred embodiment, the welding groove surface is an inclined surface, an arc surface or an irregular concave surface.

[0020] In a preferred embodiment, in Step 30, welding filler material is placed in the welding groove, and brazing process is used for welding.

[0021] In a preferred embodiment, in Step 30, laser welding process is used for welding.

[0022] In a preferred embodiment, in Step 10, the strip-shaped body is not provided with a welding groove surface, and in Step 30, laser welding process is used for welding. In a preferred embodiment, it further includes a finishing process to finish the internal thread of the nut.

[0023] The present invention also discloses a nut, which is made by the nut forming method based on the spring-type thread structure, and the internal thread of the nut is a single-start thread or a multi-start thread.

[0024] The nut forming method based on the spring-type thread structure and the nut of the present invention have the following beneficial effects compared with the prior art: (1) Relying on the geometric arrangement of the thread profile structure in the spring-type thread structure can ensure accurate lead control and thread uniformity, and the produced nut has high precision, avoiding the deviation of the traditional cutting process.

[0025] (2) Avoid overall cutting processing, improve material utilization rate, and reduce production cost.

[0026] (3) The overall nut is formed by welding strip-shaped bodies. Compared with the internal thread processing method disclosed in CN105127690A in the traditional split nut manufacturing method, the number of processes is less, it is not restricted by the welding space, the welding reliability and consistency are better, and the welding accuracy is higher; compared with the manufacturing method of the nut tube disclosed in CN117283236A, the thermal stability is better, the structural strength is higher, and the accuracy is better.

[0027] (4) It has a wider scope of application and is suitable for various nut manufacturing requirements, including the manufacture of high-strength fasteners, deep-hole nuts, high-precision robot lead screw nuts, and other special nuts. Description of the Drawings

[0028] Figure 1 It is a schematic external structure diagram of the spring-type thread structure shown in the first embodiment; Figure 2 For Figure 1 It is a schematic partial cross-sectional structure diagram after axial compression and merging of the spring-type thread structure shown; Figure 3 For Figure 2 It is a schematic diagram of the nut structure formed after the overall welding and forming of the nut structure shown; Figure 4 It is a schematic external structure diagram of the spring-type thread structure shown in the second embodiment; Figure 5 For Figure 4 It is a schematic partial cross-sectional structure diagram after axial compression and merging of the spring-type thread structure shown. Detailed Embodiments

[0029] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0031] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, an integral connection, or a detachable connection; it can be the communication inside two components; it can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] A nut forming method based on a spring - type thread structure in this embodiment includes the following steps: Step 10: Pre - fabricate the spring - type thread structure. The spring - type thread structure shown in Embodiment 1 is as Figure 1 、 Figure 2 shown, and includes a spiral - extending strip - shaped body 1, and a thread profile structure is pre - fabricated on the inner surface of the strip - shaped body 1. It should be noted that in this embodiment, there is a gap 3 between adjacent turns of the strip - shaped body 1. Of course, there may also be no obvious gap between adjacent turns of the strip - shaped body.

[0033] It should be noted that, preferably, the thread profile structure is any one of trapezoidal thread, T - shaped thread, triangular thread, arc thread, and rectangular thread, and its thread profile structure can be pre - fabricated into any required thread profile. In this embodiment, preferably, the thread profile structure is a triangular thread 7.

[0034] In addition, during the pre - fabrication process of the spring - type thread structure in this embodiment, the thread profile structure can be pre - fabricated into a single - start thread or a multi - start thread. Preferably, in this embodiment, it is a three - start thread.

[0035] A spring - type thread structure shown in Embodiment 2 is as Figure 4 、 Figure 5 shown, and the difference from the spring - type thread structure shown in Embodiment 1 is: (1) The thread profile is different. In Embodiment 2, the thread profile structure is a trapezoidal thread 8. (2) The number of thread starts is different. In Embodiment 2, the trapezoidal thread 8 is a single - start thread.

[0036] It should be noted that the pre - fabrication of the spring - type thread structure is a prior art. For example, the production of conventional springs, the production of steel strip threads in CN105127690A, and the production method of spring nuts in CN117283236A can all be used for the pre - fabrication of the spring - type thread structure in this embodiment. The present application does not limit the production method of its spring - type thread structure.

[0037] As a special feature of this embodiment, where, as Figure 1As shown, welding bevel surfaces 2 are prefabricated on both sides of the outer surface of the strip-shaped body 1. It should be noted that in this embodiment, the welding bevel surface 2 can be any conventional welding bevel surface such as an inclined surface, an arc surface or an irregular concave surface, and the present application does not limit the specific form of the welding bevel surface.

[0038] Preferably, in this embodiment, the welding bevel surface 2 is an inclined surface, and the welding bevel surfaces 2 on both sides are symmetrical.

[0039] It should be noted that setting the welding bevel surfaces 2 on both sides is a preferred implementation manner of the present application. In specific applications, setting the welding bevel surface 2 on only one side can also meet the requirements.

[0040] In addition, it should be noted that although the welding bevel surface 2 is provided in the spring-type thread structures of both Embodiment 1 and Embodiment 2, this is not the only limitation on the forming method of the present application. In the spring-type thread structure preformed in Step 10, the strip-shaped body 1 may not be prefabricated with a welding bevel surface.

[0041] Step 20: Axially compress and hold the spring-type thread structure in the Figure 2 shown compressed state, and the strip-shaped bodies 1 of adjacent turns are closely attached to each other.

[0042] Among them, in the spring-type thread structures of Embodiment 1 and Embodiment 2, since the strip-shaped body 1 is provided with the welding bevel surface 2, as Figure 2 、 Figure 5 shown, a welding groove 4 is formed at the welding bevel surface after the spring-type thread structure is axially compressed.

[0043] It should be noted that if the spring-type thread structure preformed in Step 10 is not provided with a welding bevel surface, then there will be no welding groove after the spring-type thread structure is axially compressed.

[0044] Step 30: Weld at the joint gap between the strip-shaped bodies of adjacent turns, and the prefabricated spring-type thread structure is formed into a nut structure by welding. In this embodiment, the spring-type thread structure is formed into an integral nut structure by welding, which changes the processing method of traditional nuts.

[0045] Preferably, the spring-type thread structures described in Embodiment 1 and Embodiment 2 can be welded either by a laser welding process; or by a brazing process along the welding groove 4 for integral welding, as Figure 3 shown, to form a continuous weld bead 6, so that the spring-type thread structure is formed into an integral nut. Among them, during the integral welding process, a welding filler material, such as a welding wire, is added into the welding groove to improve the strength of the nut and prevent problems such as voids or uneven structures during the welding process.

[0046] It should be noted that both the laser welding process and the brazing process are conventional welding processes in the prior art, and the specific welding processes thereof will not be elaborated in this application.

[0047] It should be noted that if the laser welding process is used for welding, after welding, according to the requirements of the application scenario, heat treatment process can be carried out when necessary to achieve the required hardness or mechanical properties of the nut. If the brazing process is used for welding, after brazing, different heat treatment processes can also be adopted according to the different requirements of the nut application scenario for hardness to obtain nut structures with different hardnesses. The specific heat treatment process is not limited in this embodiment.

[0048] In this embodiment, finish machining can also be performed on the internal thread of the nut. For example, the internal thread can be finish machined by an extrusion process to improve the accuracy of the internal thread. It should be noted that the finish machining process of the internal thread is a conventional process for existing internal threads, and the specific process thereof will not be elaborated in this embodiment.

[0049] As another equivalent embodiment of this embodiment, in step 10, the strip-shaped body is not provided with a welding groove surface. Thus, in step 30, the laser welding process is used for overall welding. The advantage of the laser welding process is that the welding strength is high and it will not affect the hardness inside the nut. After welding, according to the requirements of the application scenario, heat treatment process can be carried out when necessary to achieve the required hardness or mechanical properties of the nut.

[0050] In summary, the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A nut forming method based on a spring-type thread structure, characterized in that, At least include the following steps: Step 10: Prefabricate a spring-type thread structure, the spring-type thread structure includes a strip-shaped body extending spirally, and a thread profile structure is prefabricated on the inner surface of the strip-shaped body; Step 20: Axially compress and hold the spring-type thread structure in the compressed state, and the adjacent turns of the strip-shaped body are closely fitted; Step 30: Weld at the fitting gap between the adjacent turns of the strip-shaped body, and the prefabricated spring-type thread structure is formed into a nut structure by welding.

2. The nut forming method according to claim 1, wherein The thread profile structure is any one of trapezoidal thread, T-shaped thread, triangular thread, arc thread, and rectangular thread.

3. The nut forming method according to claim 1, characterized in that, In Step 10, at least one side of the outer surface of the strip-shaped body is prefabricated with a welding groove surface; in Step 20, after the spring-type thread structure is axially compressed, a welding groove is formed at the welding groove surface.

4. The nut forming method according to claim 3, wherein Both sides of the outer surface of the strip-shaped body are prefabricated with welding groove surfaces.

5. The nut forming method according to claim 3 or 4, characterized in that, The welding groove surface is an inclined surface, an arc surface or an irregular concave surface.

6. The nut forming method according to claim 5, characterized in that, In Step 30, welding filler material is placed in the welding groove, and brazing process is used for welding.

7. The nut forming method according to claim 5, characterized in that, In Step 30, laser welding process is used for welding.

8. The nut forming method according to claim 1, characterized in that, In Step 10, the strip-shaped body is not provided with a welding groove surface, and in Step 30, laser welding process is used for welding.

9. The nut forming method according to claim 1-4 or 6-8, characterized in that, It further includes a finishing process to finish the internal thread of the nut.

10. A nut, characterized in that, Made by the nut forming method based on the spring-type thread structure according to any one of claims 1-9, and the internal thread of the nut is a single-start thread or a multi-start thread.

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