Threaded fastener capable of automatically guiding

Abstract

The utility model discloses a threaded fastener capable of automatically guiding, which comprises a guiding section and a screwing-in section, a guiding section is arranged between the guiding section and the screwing-in section, the guiding section is provided with at least two circles of guiding threads, and the crest surfaces of the guiding threads are arranged in a plane; the device has the advantages that when the bolt obliquely enters the internal threaded hole, the bolt can be automatically guided by means of the structure of the thread, so that the bolt can be smoothly screwed into the internal threaded hole.

Description

Technical Field

[0001] The utility model relates to a thread fastener, in particular to a thread fastener capable of automatically guiding. Background Art

[0002] In the field of modern automobile manufacturing, fasteners are an indispensable and important component in the automobile assembly process. On average, each passenger car uses about 2,000 fasteners, covering key parts such as the vehicle frame, gearbox, engine and chassis. Due to the widespread use and complex distribution of fasteners in various parts of the car, assembly work faces a variety of complex and challenging conditions, especially in limited space. Workers are burdened with heavy responsibilities during assembly. It is often difficult to accurately locate the specific position of the threaded holes due to obstructed vision and visual blind spots. This situation depends largely on the experience and craftsmanship of the workers.

[0003] If the operators in the fastening process perform repetitive labor for a long time, they are very likely to become fatigued, resulting in reduced operating accuracy, making the alignment of bolts and nuts very difficult. If there is an axial deviation, even a slight cross misalignment, it may prevent the bolt from being smoothly screwed into the threaded hole, which will seriously affect the assembly efficiency and extend the production cycle. In order to solve this problem, workers must try to adjust the bolt position many times. This adjustment process not only consumes time, but also significantly disrupts the production process and reduces the overall production line efficiency.

[0004] In addition, in the face of assembly difficulties, some workers may take non-ideal countermeasures, even if the bolts and threaded holes are not completely aligned, they still use force to tighten to achieve the tightening goal. This practice may generate excessive friction between the bolts and the internal threads, causing thread damage or bolt seizure, and even bolt breakage in severe cases, which will directly endanger the safe operation and durability of the car and increase the risk of quality problems. In conventional tightening operations, the metric thread has a 60° tooth angle, the external thread crest should be used in conjunction with the internal thread root, and the external thread root is matched with the internal thread crest. When the bolt is screwed in at an inclined angle, the external thread crest often contacts the internal thread crest, and the external thread root and the internal thread root contact at the same time, resulting in invalid matching and the problem of not being able to screw in smoothly. Utility Model Content

[0005] The utility model aims to solve the above problems and provides a threaded fastener capable of automatic guiding, so that when the bolt is tilted into an internal threaded hole, the structure of the thread itself can realize automatic guiding of the bolt, so that the bolt can be smoothly screwed into the internal threaded hole.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions: a threaded fastener capable of automatic correction, comprising a guide section and a screw-in section, a correction section is provided between the guide section and the screw-in section, the correction section has at least two circles of correction threads, and the top surface of the correction threads is a plane setting.

[0007] Preferably, the tooth profile of the guide thread is a trapezoidal thread, a wavy thread, a rectangular thread or a serrated thread.

[0008] Preferably, the length of the guiding section is L, L=2P-2.5P, wherein P is the pitch of the guiding thread.

[0009] Preferably, the screw-in section has a threaded portion, and a pitch of the threaded portion is consistent with a pitch of the pilot thread.

[0010] Preferably, the tooth bottom of the guide thread adopts an arc transition with a radius of R, satisfying 0.15P≤R≤0.20P.

[0011] Preferably, the tooth profile of the threaded portion is a triangular thread, and the tooth height of the pilot thread is 35%-55% of the tooth height of the threaded portion.

[0012] Preferably, the length of the guide section is longer than that of the guiding section, and shorter than that of the screw-in section.

[0013] Preferably, the front end of the guide section is provided with a chamfer.

[0014] Compared with the prior art, the advantages of the utility model are: the guiding section containing at least two circles of guiding threads arranged between the guide section and the screw-in section cleverly solves the common alignment problem in threaded docking. The key feature of this guiding thread is that its tooth top surface is designed to be a plane. This design makes it possible for the plane top surface of the guiding section to effectively contact the thread of the matching fastener if the axis is not fully aligned when the threaded fastener is initially screwed in, even if there is a slight tilt. Through a simple rotation action, these plane tooth tops can guide the fastener to self-adjust to the correct alignment position, which not only reduces the difficulty of operation during installation and improves work efficiency, but also reduces the risk of thread damage caused by improper installation, ensuring the reliability of the connection and the service life of the fastener. In addition, this design also means that less force is required during the tightening process, making the operation easier, thereby increasing the installation speed while also ensuring the safety of the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. It is obvious that the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0016] Figure 1 It is a structural schematic diagram of the utility model;

[0017] Figure 2 It is a schematic diagram of the first correction process of the utility model;

[0018] Figure 3 It is a schematic diagram of the second correction process of the utility model;

[0019] Figure 4 It is a schematic diagram of the third correction process of the utility model;

[0020] In the figure, 1, guide section; 2, screw-in section; 3, guide section; 4, guide thread; 5, threaded portion; 6, chamfer. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] Embodiment 1: As shown in the figure, a threaded fastener capable of automatic self-alignment comprises a guide section 1 and a screw-in section 2, a guide section 3 is provided between the guide section 1 and the screw-in section 2, the guide section 3 has at least two circles of guide threads 4, and the top surface of the guide threads 4 is a plane setting.

[0023] The design goal of the flat crest of pilot section 3 is to provide a wider contact surface during the initial screw-in phase when the axis of the threaded fastener may be misaligned. This has three main effects:

[0024] 1. Increased contact area: Compared with traditional triangular or other sharp-topped threads, flat crests can provide a larger contact area under inclined conditions. This larger contact area helps to disperse the pressure on the thread contact point, reduce the risk of local damage, and ensure better contact and fit with the mating thread;

[0025] 2. Automatic guiding effect: When the axis of the threaded fastener is not aligned during installation, the flat top of the thread can form a physical guiding and correction mechanism by contacting the internal thread and utilizing the characteristics of its wider top surface being placed in parallel. This physical mechanism can effectively guide the tilted threaded fastener to realign and allow it to be screwed in smoothly without getting stuck or damaging the thread.

[0026] 3. Improve installation efficiency and reduce errors: Due to the guiding characteristics of the flat top, even if the operator cannot visually confirm the alignment of the bolt and nut, it can ensure that the fasteners are installed correctly and smoothly. This not only improves installation efficiency and reduces installation time, but also significantly reduces losses caused by installation errors.

[0027] Embodiment 2: As shown in the figure, different from Embodiment 1, the tooth profile of the guide thread 4 is a trapezoidal thread, a wavy thread, a rectangular thread or a serrated thread.

[0028] In the present structure, the tooth profile design adopted by the guide thread 4 includes trapezoidal thread, wavy thread, rectangular thread or serrated thread. The common advantage of these tooth profiles is that they can provide a larger tolerance space in the initial stage of the fastener, so that the thread can be smoothly guided and corrected to the correct position even when the axis is not fully aligned, and then smoothly screwed in.

[0029] The trapezoidal thread, with its wide top and narrow bottom shape, optimizes the contact area and reduces the concentrated pressure and damage caused by inaccurate docking; the wavy thread provides more flexible adaptability through its changing crests and troughs, which can effectively disperse the force between different stress points and reduce the risk of jamming; the rectangular thread can provide a more stable grip due to its straight tooth edge, which increases the guiding stability during initial contact; the serrated thread provides an automatic alignment anchoring effect through its sharp tooth edge during contact, ensuring that the fastener can be effectively pulled into the correct track even in the case of inaccurate alignment. During production, the guiding thread 4 selects the shape of the thread according to the actual use needs, so that the threaded fastener can adapt to different working environments.

[0030] In this embodiment, the length of the guiding section 3 is L, where L=2P-2.5P, wherein P is the pitch of the guiding thread 4 .

[0031] The length L of the guiding section 3 is set to L=2P-2.5P, where P represents the pitch of the guiding thread 4, and is intended to optimize the guiding performance and deviation correction capability of the guiding thread 4. This length setting ensures that the guiding thread 4 has sufficient contact area and guiding length to effectively deal with the axis deviation problem that may exist during the installation of the fastener. When the fastener begins to be screwed in but is not fully aligned with the receiving hole, this specific length of the guiding section 3 provides a gradual introduction and correction process. During this process, the threaded fastener can automatically adjust its axis before entering the screw-in section 2 to ensure smooth docking, effectively optimizing the installation performance and use effect of the fastener.

[0032] In this embodiment, the screw-in section 2 has a threaded portion 5 , and the pitch of the threaded portion 5 is consistent with the pitch of the pilot thread 4 .

[0033] In the above structure, by maintaining the consistency of the pitch, the fastener can smoothly enter the screw-in section 2 after the axial deviation of the guide thread 4 is self-corrected, thereby achieving high-efficiency and high-precision fastening. It not only avoids the sudden increase in screw-in resistance caused by different pitches, but also ensures the stability and reliability of the threaded fastener during the entire screw-in process. In addition, this pitch consistency design is also conducive to improving the load-bearing capacity of the fastened joint. Since the pitch of the screw-in section 2 and the guide section 3 is the same, the fit between the threads is tighter, reducing the possibility of loosening and enhancing the overall stability and durability of the fastening structure.

[0034] Embodiment 3: As shown in the figure, different from Embodiment 2, the tooth bottom of the pilot thread 4 adopts an arc transition, and its radius R satisfies 0.15P≤R≤0.20P.

[0035] When the fastener starts to screw in and automatically guides, the arc-shaped bottom of the tooth makes each contact of the tooth line smoother, which helps to alleviate the difficulty of screwing in due to axis misalignment, and also makes the transition between threads smoother. In addition, the arc transition design also helps to reduce the friction and wear caused by misalignment between threads during the tightening process, thereby extending the service life of the fastener and the corresponding connection parts.

[0036] Selecting 0.15P to 0.2P as the range of arc radius carefully balances the transition curvature with the need for guiding capability in actual operation, which not only ensures sufficient guiding effect but also avoids weakening of the thread's load-bearing capacity due to excessive curvature.

[0037] In this embodiment, the thread profile of the threaded portion 5 is a triangular thread, and the thread height of the pilot thread 4 is 35%-55% of the thread height of the threaded portion 5 .

[0038] In the above structure, the triangular thread of the threaded portion 5 is widely used in a variety of fasteners because of its simple structure, convenient manufacturing and large contact area, providing good fastening and sealing performance. The triangular thread is used as the main thread shape to ensure good compatibility and versatility between the fastener and the mating part. The tooth height of the pilot thread 4 is designed to be 35%-55% of the tooth height of the threaded portion 5, which means that the pilot thread 4 has a smaller tooth height than the main thread. This design makes it so that when the fastener starts to screw in, the first thing it contacts is the pilot thread 4 with a smaller tooth height. These threads are relatively easier to enter the mating threaded hole due to their smaller tooth height. When the axis of the fastener is slightly deflected, the smaller tooth height has better fault tolerance, which can effectively guide and adjust the fastener to align it correctly and avoid cross-threading or jamming. In addition, since the guide thread 4 has a smaller tooth height, after the guiding effect on the fastener is completed during the initial screwing in, the main thread (triangular thread) will then bear a greater load-bearing capacity, ensuring the firmness of the connection. This design not only achieves high-efficiency guiding at the beginning stage of tightening, but also ensures reliability and stability at the end stage of tightening.

[0039] Embodiment 4: As shown in the figure, the difference from Embodiment 3 is that the length of the guide section 1 is longer than the length of the guide section 3 and shorter than the length of the screw-in section 2.

[0040] In the above structure, the guide section 1 is the initial part of the fastener contacting the mating part. Its length exceeds the guiding section 3, which means that its main function is to provide initial pointing and guidance for the fastener when entering the target screw hole. The longer guide section 1 can increase the stability of contact with the target accessory, reduce the difficulty of screwing in due to indirect alignment, and lay the foundation for the smooth transition between the guiding section 3 and the screwing section 2.

[0041] The guiding section 3 is shorter than the guiding section 1, which provides sufficient space and time for precise axis correction. The slight axial deviation that may exist in the initial stage of screwing in can be effectively corrected. The guiding section 3 is deliberately controlled to be shorter in length, aiming to complete the guiding function as soon as possible to avoid reduced screwing efficiency due to excessive length, and to give way to the screwing-in section 2 responsible for the final fixation in time.

[0042] As the final tightening stage, screw-in section 2 is the longest in length, with the purpose of ensuring that the fastener can penetrate deep into the fitting and provide sufficient gripping force and connection stability through sufficient thread contact area. This design of screw-in section 2 not only ensures the tightening force, but also ultimately locks the position of the fastener.

[0043] In this embodiment, a chamfer 6 is provided at the front end of the guide section 1 .

[0044] The introduction of chamfer 6 is mainly based on improving the initial guidance of the fastener screwing process and reducing the difficulty of alignment in the initial installation. When the fastener begins to enter the matching screw hole, it is often difficult for the operator to manually position it with complete accuracy. At this time, chamfer 6 plays a role in finding the hole. Even if the axis of the fastener and the screw hole deviates slightly, chamfer 6 can slide and contact the edge of the screw hole, and guide the axis of the fastener to align with the axis of the screw hole under the action of slight force, making the screwing action smoother and reducing the risk of local deformation or damage caused by direct hard collision.

[0045] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A threaded fastener capable of self-guiding, comprising a guide section and a screw-in section, characterized in that: A guiding section is provided between the guide section and the screw-in section. The guiding section has at least two circles of guiding threads, and the top surface of the guiding threads is a plane.

2. The self-guiding threaded fastener according to claim 1, characterized in that: The tooth profile of the guide thread is a trapezoidal thread, a wavy thread, a rectangular thread or a sawtooth thread.

3. The self-guiding threaded fastener according to claim 1, characterized in that: The length of the guiding section is L, L=2P-2.5P, wherein P is the pitch of the guiding thread.

4. A self-guiding threaded fastener according to claim 1 or 3, characterized in that: The screw-in section has a threaded portion, and the pitch of the threaded portion is consistent with the pitch of the pilot thread.

5. The self-guiding threaded fastener according to claim 3, characterized in that: The tooth bottom of the guide thread adopts an arc transition, and its radius is R, satisfying 0.15P≤R≤0.20P.

6. The self-guiding threaded fastener according to claim 4, characterized in that: The tooth profile of the threaded portion is a triangular thread, and the tooth height of the pilot thread is 35%-55% of the tooth height of the threaded portion.

7. The self-guiding threaded fastener according to claim 1, characterized in that: The length of the guide section is longer than that of the guiding section, and shorter than that of the screw-in section.

8. The self-guiding threaded fastener according to claim 1, characterized in that: The front end of the guide section is provided with a chamfer.

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