Screw joint piece
By combining trapezoidal or sawtooth guide threads with ordinary thread molds in the screw connectors, the problem of screw connectors being screwed into different shafts is solved, achieving efficient screwing and low-cost manufacturing.
Patent Information
- Application Number
- CN202422207703.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2034-09-09
AI Technical Summary
Existing screw-in components are prone to misalignment during screwing, resulting in uneven screwing and low success rate, and the use of special molds is costly.
Design a screw connector that uses a trapezoidal or sawtooth guide thread with a thread height smaller than that of the fixed thread. It is prepared using a common thread mold. The guide thread has a large contact area with the internal thread, providing greater force, correcting the axis of the screw connector, and improving the smoothness and success rate of screwing.
The self-guiding effect improves the smoothness and success rate of screwing in the screws, reduces manufacturing costs, and does not rely on high-cost special molds.
Smart Images
Figure CN223839507U_ABST
Abstract
Description
Technical Field
[0001] The embodiments of this application relate to the field of mechanical connection structure technology, and more particularly to a screw connector. Background Technology
[0002] Threaded connections are a widely used connection method in various mechanical structures. During a threaded connection, a threaded fitting with external threads is screwed into a mating part with internal threads, allowing the internal and external threads to engage and thus achieve a fixed connection. However, in actual connection processes, due to accumulated manufacturing errors, improper operation, and other reasons, the threaded fitting and the mating part often become misaligned, preventing the threaded fitting from being screwed in smoothly. Utility Model Content
[0003] In view of this, the embodiments of this application aim to provide a screw connector that can improve screwing smoothness and success rate, and has a lower cost.
[0004] An embodiment of this application provides a screw connector, the screw connector comprising: a cylindrical body having a head end and a tail end on opposite sides along the axial direction; a fixed thread disposed on the cylindrical body; and a guide thread disposed on the cylindrical body and located between the fixed thread and the head end, wherein the tooth profile of the guide thread is trapezoidal or sawtooth, and the tooth height of the guide thread is less than the tooth height of the fixed thread.
[0005] In some embodiments, the tooth height of the guide thread gradually increases along the direction close to the fixed thread.
[0006] In some embodiments, along the direction close to the fixed thread, the crest surface of the guide thread is inclined toward the direction away from the cylindrical body.
[0007] In some embodiments, the crest surface of each thread of the guide thread is coplanar with a tapered surface.
[0008] In some embodiments, the tooth profile of the fixed thread is triangular, and the tooth profile of the guide thread is trapezoidal.
[0009] In some embodiments, the number of turns of the guide thread is N, where 2 ≤ N ≤ 5.
[0010] In some embodiments, the guide thread engages with the fixed thread.
[0011] In some embodiments, the pitch and helix angle of the guide thread are the same as those of the fixed thread.
[0012] In some embodiments, the guide thread is spaced apart from the head end of the columnar body, such that the circumferential surface of the columnar body located between the guide thread and the head end is exposed to form a cylindrical surface.
[0013] In some embodiments, an arc-shaped transition surface is formed between the cylindrical surface and the end face of the head end.
[0014] The screw connectors in this application have a self-guiding effect, which can improve the smoothness and success rate of screwing in, and the manufacturing cost is low. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of the screw connector according to an embodiment of this application;
[0016] Figure 2 This is a schematic diagram of the tooth profile of the guide thread and the fixing thread of the screw connector according to an embodiment of this application;
[0017] Figure 3 This is a schematic diagram of the tooth profiles of the guide thread and the fixing thread of a screw connector according to another embodiment of this application;
[0018] Figure 4 This is a schematic diagram of the tooth profile of the guide thread and the fixing thread of the screw connector according to another embodiment of this application.
[0019] Explanation of reference numerals in the attached figures
[0020] 1. Columnar body; 1a. Head end; 1b. Tail end; 11. Cylindrical surface; 12. Arc-shaped transition surface; 2. Fixed thread; 3. Guide thread; 3a. Tooth crest surface. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.
[0022] The specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction. For example, different combinations of specific technical features can form different embodiments and technical solutions. To avoid unnecessary repetition, the various possible combinations of the specific technical features in this application will not be described separately.
[0023] In the following description, the terms "first," "second," etc., are used merely to distinguish different objects and do not indicate that the objects have the sameness or relationship. It should be understood that the directional descriptions "above," "below," "outside," and "inside" refer to the orientation under normal use conditions, while "left" and "right" refer to the left and right directions shown in the corresponding diagrams, which may or may not be the left and right directions under normal use conditions.
[0024] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. "A plurality of" means two or more.
[0025] An embodiment of this application provides a screw connector, referring to... Figures 1-4 The screw connector includes a cylindrical body 1, a fixing thread 2, and a guide thread 3.
[0026] The cylindrical body 1 has a head end 1a and a tail end 1b on opposite sides along the axial direction. It can be understood that the axial direction here is both the axial direction of the cylindrical body 1 itself and the axial direction of the entire screw connection. The head end 1a specifically refers to the end of the cylindrical body 1 that enters the mating part first during the actual connection process, while the tail end 1b is the other end of the cylindrical body 1 opposite to the head end 1a.
[0027] In actual use, the user can hold the tail end 1b of the columnar body 1 or use an external connecting tool (such as a screwdriver or power tool gun) to apply force to the tail end 1b of the columnar body 1, thereby screwing the columnar body 1 into the mating part. As an example, the end face of the tail end 1b of the columnar body 1 can be formed with a connecting structure for mating with external connecting tools, such as a slotted groove, a cross-shaped groove, a polygonal groove, etc. Alternatively, the tail end 1b of the columnar body 1 can be formed with a gripping structure that is easy for the user to hold. Or, the screwing part can include a cap-shaped structure connected to the tail end 1b of the columnar body 1, with the cap-shaped structure forming a connecting structure on the side surface of the columnar body 1 facing away from it. There are no restrictions on this.
[0028] The fixing thread 2 is provided on the columnar body 1. The thread mentioned here and in other parts below specifically refers to the helical continuous protrusion with a specific cross-section made on the circumferential surface of the columnar body 1.
[0029] The fixing thread 2 is used to engage with the internal thread of the mating part to achieve a fixed connection. The specific tooth profile, tooth height, pitch, number of turns, and other related parameters of the fixing thread 2 can be determined by those skilled in the art based on the relevant parameters of the internal thread in the mating part that is suitable for actual needs, and there are no restrictions on this. As an example, the tooth profile of the fixing thread 2 can be triangular, trapezoidal, or sawtooth.
[0030] The term "tooth profile" as used here and elsewhere in the text refers specifically to the cross-sectional geometry of the thread. "Tooth height" specifically refers to the distance from the crest to the root of the thread in a direction perpendicular to the thread axis (i.e., the axis of the cylindrical body 1). "Pitch" specifically refers to the axial distance between two corresponding points on the pitch diameter line of two adjacent threads.
[0031] The guide thread 3 is provided on the columnar body 1 and located between the fixed thread 2 and the head end 1a. The guide thread 3 is mainly used to correct the axis of the screwed part to be approximately coaxial with the axis of the internal thread on the mating part during the screwing process. That is, it provides self-guidance during the screwing process, so that the subsequent fixed thread 2 can engage with the internal thread more smoothly.
[0032] In related technologies, curved threads are typically used for guidance. Since the curved thread cannot fully engage with the internal thread, it can be screwed into the internal thread even when the screwed component is not aligned with the internal thread. When the curved thread is screwed into the internal thread, but the subsequent fixing thread has not yet entered the internal thread, the screwed component can wobble relative to the axis of the internal thread. Therefore, as the curved thread continues to be screwed in, the axial direction of the screwed component will be corrected by the force generated by the contact between the curved thread and the internal thread.
[0033] However, it is understandable that curved threads are not commonly used in this field and require special thread molds for preparation. The cost of such special thread molds is much higher than that of ordinary thread molds commonly used in this field (such as triangular thread molds, trapezoidal thread molds, sawtooth thread molds, etc.), and their lifespan is also much shorter than that of ordinary thread molds. This results in a higher manufacturing cost for screw-in parts using curved threads.
[0034] To solve the above problems, in this embodiment, the tooth profile of the guide thread 3 is set to be trapezoidal or sawtooth, and the tooth height of the guide thread 3 is set to be less than the tooth height of the fixed thread 2.
[0035] It is understandable that, in order to achieve a fixed connection, the tooth height of the guide thread 3 is usually approximately the same as that of the internal thread in the mating part. Since the tooth height of the guide thread 3 is smaller than that of the fixed thread 2, the guide thread 3 and the internal thread will not fully engage, but there will be a certain gap. This gap allows the guide thread 3 to be screwed into the internal thread even when the screwed part and the internal thread are not on the same axis. Furthermore, when only the guide thread 3 is screwed in and the fixed thread 2 is not screwed in, there will be a certain amount of wobble relative to the axis of the internal thread. As the guide thread 3 continues to be screwed in, the axial direction of the screwed part will be corrected by the force generated by the contact between the guide thread 3 and the internal thread, allowing the subsequent fixed thread 2 to smoothly engage with the internal thread, thus improving the smoothness and success rate of screwing in the screwed part.
[0036] Compared with the arc-shaped threads used in related technologies, the guide thread 3 in this embodiment can provide a greater force when it contacts the internal thread (because the trapezoidal thread and sawtooth thread have a larger effective contact area with the internal thread), thus resulting in a better self-guiding effect.
[0037] Furthermore, it can be understood that in this embodiment, both trapezoidal and sawtooth threads are commonly used threads in the art. Therefore, the guide thread 3 in this embodiment can be prepared using a common thread mold, resulting in relatively low manufacturing costs. In addition, the tooth profile of the fixed thread 2 in the art is typically selected from triangular, trapezoidal, or sawtooth shapes. Regardless of which tooth profile is chosen, it can be formed into a trapezoidal or sawtooth thread with a small tooth height through cutting, grinding, or other methods. This means that the fixed thread 2 and the guide thread 3 can be prepared using the same mold, further reducing manufacturing difficulty and cost.
[0038] As an example, in the actual preparation process, a triangular thread can be formed on the cylindrical body 1 using a triangular thread mold. Then, the tooth tip of the section of the triangular thread near the head end 1a is cut or ground into a flat surface, so that the tooth height of this part of the thread is reduced and the tooth shape becomes trapezoidal, thereby forming a guide thread 3. The remaining unground part forms a fixed thread 2.
[0039] As another example, in the actual preparation process, a trapezoidal thread mold or a sawtooth thread mold can be used to form a trapezoidal thread or a sawtooth thread on the cylindrical body 1. Then, by cutting or grinding the tooth tip of a section of the trapezoidal thread or sawtooth thread head end 1a, the tooth height of that part of the thread is reduced, thereby forming a guide thread 3. The remaining unground part forms a fixed thread 2.
[0040] Of course, those skilled in the art can also choose to use two different specifications of thread molds to prepare the guide thread 3 and the fixed thread 2 respectively. Since the two molds used are common thread molds commonly used in the field, only the specifications are different, the effect of reducing the preparation difficulty and cost can also be achieved.
[0041] In some embodiments, refer to Figure 2 Along the direction close to the fixed thread 2, the tooth height of the guide thread 3 gradually increases. In this embodiment, because the tooth height of the guide thread 3 gradually increases, as the guide thread 3 is screwed in, its engagement with the internal thread will become increasingly tight, thereby continuously providing force to correct the axial direction of the screwed part, thus achieving a better self-guiding effect.
[0042] by Figure 2 For example, Figure 2The guide thread 3 shown in the figure has three threads. Along the direction close to the fixed thread 2, the thread heights of the three threads are H1, H2, and H3, respectively, where H1 < H2 < H3. It should be noted that in this embodiment, H1, H2, and H3 can form an arithmetic sequence or a non-arithmetic sequence, and there is no limitation on this.
[0043] Of course, in other embodiments, reference is made to Figure 3 The tooth height of guide thread 3 can remain unchanged.
[0044] In some embodiments, still refer to Figure 2 Along the direction close to the fixed thread 2, the crest surface 3a of the guide thread 3 is inclined in a direction away from the cylindrical body 1. Here, the crest surface 3a specifically refers to the side surface of the guide thread that is away from the cylindrical body 1.
[0045] Compared with the embodiment where the tooth crest surface 3a is parallel to the axis of the columnar body 1, the tooth crest surface 3a in this embodiment, which is inclined in the above direction, can generate a greater force in the axial direction of the columnar body 1 when the guide thread 3 contacts the internal thread, thereby achieving a better self-guiding effect.
[0046] Of course, in some other embodiments, refer to Figure 3 The crest surface 3a of the guide thread 3 can also be parallel to the axis of the cylindrical body 1.
[0047] In some embodiments, still refer to Figure 2 The crest surface 3a of each thread of the guide thread 3 is coplanar with a tapered surface. Specifically, Figure 2 The diagram shows three threads of the guide thread 3, with the crest surfaces 3a of the three threads aligned on the same straight line. Thus, in the actual manufacturing process, a conical grinding wheel can be used to grind the thread to form the guide thread 3, further reducing the manufacturing difficulty and cost.
[0048] Of course, in some other embodiments, refer to Figure 4 The crest surfaces 3a of each thread of the guide thread 3 may not be coplanar.
[0049] In some embodiments, the number of turns of the guide thread 3 is N, where 2 ≤ N ≤ 5. It is understood that too few turns of the guide thread 3 may result in poor self-guiding performance, while too many turns may reduce the number of turns of the fixing thread 2, potentially failing to achieve the desired tightening performance. Therefore, in this embodiment, the number of turns of the guide thread 3 is set to 2-5 turns, thereby balancing the self-guiding effect and tightening performance of the screwed connection.
[0050] In some embodiments, the tooth profile of the fixing thread 2 is triangular, and the tooth profile of the guide thread 3 is trapezoidal. Setting the tooth profile of the fixing thread 2 as triangular helps to improve the fastening performance of the screwed connection, while setting the tooth profile of the guide thread 3 as trapezoidal allows the guide thread 3 to be manufactured by the cutting, grinding and other methods mentioned above, reducing the manufacturing difficulty and cost.
[0051] In some embodiments, the guide thread 3 engages with the fixed thread 2. This further improves the smoothness of screwing in the bolted component and makes the thread distribution on the bolted component more compact, making it easier to meet the number of turns required by the fixed thread 2 and achieving a better tightening effect.
[0052] In some embodiments, the pitch and helix angle of the guide thread 3 are the same as those of the fixed thread 2. This further improves the smoothness of screwing in the threaded parts.
[0053] In some embodiments, refer to Figure 1 The guide thread 3 is spaced apart from the head end 1a of the cylindrical body 1, so that the circumferential surface of the cylindrical body 1 located between the guide thread 3 and the head end 1a is exposed to form a cylindrical surface 11. This cylindrical surface 11 can perform preliminary correction of the axis of the screwed part before the guide thread 3 is screwed into the internal thread, thereby further improving the smoothness of screwing in the screwed part.
[0054] In some embodiments, an arc-shaped transition surface 12 is formed between the cylindrical surface 11 and the end face of the head end 1a. The arc-shaped transition surface 12 can further improve the smoothness of the cylindrical surface 11 entering the internal thread, thereby further improving the smoothness of screwing in the screwed parts.
[0055] In the description of this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine different embodiments or examples described in this application, as well as features of different embodiments or examples.
[0056] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A screw connector, characterized in that, The screw connector includes: The columnar body has a head end and a tail end on opposite sides along the axial direction; A fixed thread is provided on the cylindrical body; A guide thread is provided on the cylindrical body and located between the fixed thread and the head end. The tooth profile of the guide thread is trapezoidal or sawtooth, and the tooth height of the guide thread is less than that of the fixed thread. Along the direction close to the fixed thread, the tooth crest of the guide thread is inclined in the direction away from the cylindrical body.
2. The screw connector according to claim 1, characterized in that, Along the direction close to the fixed thread, the tooth height of the guide thread gradually increases.
3. The screw connector according to claim 1, characterized in that, The crest surface of each thread of the guide thread is coplanar with a tapered surface.
4. The screw connector according to claim 1, characterized in that, The fixed thread has a triangular tooth profile, and the guide thread has a trapezoidal tooth profile.
5. The screw connector according to claim 1, characterized in that, The number of turns of the guide thread is N, where 2 ≤ N ≤ 5.
6. The screw connector according to claim 1, characterized in that, The guide thread is connected to the fixed thread.
7. The screw connector according to claim 1, characterized in that, The pitch and helix angle of the guide thread are the same as those of the fixed thread.
8. The screw connector according to claim 1, characterized in that, The guide thread is spaced apart from the head end of the columnar body, so that the circumferential surface of the columnar body located between the guide thread and the head end is exposed to form a cylindrical surface.
9. The screw connector according to claim 8, characterized in that, An arc-shaped transition surface is formed between the cylindrical surface and the end face of the head end.