Threaded structure, threaded connection pair, and stud manufacturing method

Abstract

The application discloses a thread structure, which comprises a conical thread section and a cylindrical thread section which is connected with the small end thread of the conical thread section; the conical thread section and the cylindrical thread section both comprise mating thread parts with equal pitches to be able to match with the same cylindrical mating thread; the pitch of the thread section close to the cylindrical thread section of the conical thread section and / or the pitch of the thread section close to the conical thread section of the cylindrical thread section is increased or decreased compared with the pitch of the mating thread part. The thread structure can effectively solve the problem that the thread structure cannot effectively adjust the circumferential relative position relationship of the thread angle when being locked. The application further discloses a threaded connection pair comprising the thread structure, and further discloses a stud manufacturing method for producing the thread structure.

Description

Technical Field

[0001] This invention relates to the field of connection technology, and more specifically, to a threaded structure, a threaded connection pair including the threaded structure, and a method for manufacturing a stud for producing the aforementioned threaded structure. Background Technology

[0002] In the field of liquid pipeline connections, several sealing methods are commonly used to achieve sealed connections between pipes and between pipes and components. Welding is a non-removable connection, sealing rings have strict requirements for the sealing structure, and raw rubber tape and sealant are commonly used for threaded connections. Raw rubber tape is prone to shedding debris when cut by the threads during use; therefore, threadlocker is widely used for sealing threaded connections in liquid pipelines.

[0003] Currently, in threaded connections and thread sealant systems, the relative circumferential position of the threaded pair is uncontrollable. This uncontrollability stems primarily from two reasons: First, for cylindrical threads, the threaded pair is generally a clearance fit. During thread tightening, the reverse tension is typically provided by end-face contact. Since the starting position of the internal and external threads is uncertain, the relative position after tightening is also uncertain. Second, for tapered threads, there are machining errors. The size within the tolerance range determines the different thread clearances, resulting in an uncertain tightening depth and thus an uncertain relative positional relationship.

[0004] In summary, how to effectively solve the problem of the inability to effectively adjust the relative circumferential position of the threaded structure during locking is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the first objective of the present invention is to provide a threaded structure that can effectively solve the problem that the relative position of the circumferential threads with the corresponding mating threads cannot be effectively adjusted when the threaded structure is locked. The second objective of the present invention is to provide a threaded connection pair including the threaded structure. The third objective of the present invention is to provide a stud manufacturing method for producing the above-mentioned threaded structure. The fourth objective of the present invention is to provide a stud manufacturing method for producing the above-mentioned threaded structure.

[0006] To achieve the first objective mentioned above, the present invention provides the following technical solution:

[0007] A threaded structure includes a tapered thread section and a cylindrical thread section that is threaded to the small end of the tapered thread section; both the tapered thread section and the cylindrical thread section include mating thread portions with equal pitch to mate with the same cylindrical mating thread, wherein the pitch of a section of the tapered thread section near the cylindrical thread section and / or the pitch of a section of the cylindrical thread section near the tapered thread section is increased or decreased compared to the pitch of the mating thread portion.

[0008] In use, when both the cylindrical and tapered thread sections are threaded into the cylindrical mating thread, they respectively mate at different thread portions of the cylindrical mating thread. During tightening, because at least one of the cylindrical and tapered thread sections at their closest points experiences a change in pitch, at least one type of engagement occurs. This means that during initial engagement, a portion of the tapered thread near the major diameter section is no longer centered within the groove of the cylindrical mating thread, but rather offset. At this point, the torque can be further increased to cause adaptive deformation of the thread structure and / or the cylindrical mating thread, allowing the thread structure to continue to advance. This, in turn, allows adjustment of the angular positional relationship between the thread structure and the cylindrical mating thread to meet predetermined positional requirements. In summary, this thread structure effectively solves the problem of the inability to effectively adjust the circumferential relative positional relationship of the mating threads during tightening.

[0009] Preferably, compared to the mating thread portion of the conical thread segment, the thread teeth or grooves of the conical thread segment near the cylindrical thread segment are widened.

[0010] Preferably, the pitch at the junction of the tapered thread section and the cylindrical thread section is larger than the pitch of the mating thread section.

[0011] Preferably, the pitch between the threads on the conical thread segment and the pitch between the threads on the cylindrical thread segment are equal; the tooth width of the conical thread segment is smaller than the tooth width of the cylindrical thread segment, so that the pitch between adjacent threads at the junction of the conical thread segment and the cylindrical thread segment is increased compared to the pitch of the mating thread portion.

[0012] Preferably, both the tapered thread section and the cylindrical thread section are external threads.

[0013] Preferably, the major diameter section of the tapered thread segment has a relief groove.

[0014] Preferably, both the tapered thread section and the cylindrical thread section are internal threads.

[0015] To achieve the second objective mentioned above, the present invention also provides a threaded connection pair, which includes a first component and a second component having a cylindrical mating thread, and further includes any of the aforementioned thread structures. Both the conical thread section and the cylindrical thread section of the thread structure are mated with the cylindrical mating thread, and the pitch of the mating thread portion of the thread structure is equal to the pitch of the cylindrical mating thread. Since the aforementioned thread structure has the above-mentioned technical effects, the threaded connection pair having this thread structure should also have corresponding technical effects.

[0016] To achieve the third objective mentioned above, the present invention also provides a method for manufacturing a stud that fits into an internal thread of a cylinder, comprising the following steps:

[0017] The driving machining cylinder rotates relative to the tool in a preset direction and at a preset speed around the axis, and translates relative to the tool along the axis at a first speed at a preset distance, so that the tool processes the front section of the thread;

[0018] The driving machining column rotates uniformly around the axis relative to the tool in the preset direction and at the preset rotation speed, and translates relative to the tool along the axis at a preset distance at a second speed not equal to the first speed, so that the tool processes the intermediate section of the thread;

[0019] The driving machining cylinder rotates uniformly around the axis relative to the tool in the preset direction and at the preset speed, and translates relative to the tool along the axis at the first speed for a preset distance, so that the tool processes the rear thread, one of the front thread and the rear thread is a cylindrical thread and the other is a tapered thread.

[0020] Since the aforementioned thread structure has the aforementioned technical effects, the stud manufacturing method used to manufacture the thread structure and its fit with the internal thread of a cylinder should also have the corresponding technical effects.

[0021] To achieve the fourth objective mentioned above, the present invention also provides a method for manufacturing a stud that fits into an internal thread of a cylinder, comprising the following steps:

[0022] A stud with a tapered thread section and a cylindrical thread section is obtained, wherein the cylindrical thread section is threadedly connected to the small end of the tapered thread section, and the thread pitch of the tapered thread section, the thread pitch of the cylindrical thread section, and the thread pitch at the connection are all equal.

[0023] The tapered thread section is cut on one side.

[0024] Since the aforementioned thread structure has the aforementioned technical effects, the stud manufacturing method used to manufacture the thread structure and its fit with the internal thread of a cylinder should also have the corresponding technical effects. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of a threaded structure provided in an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of another threaded structure provided in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of a threaded structure and a cylindrical mating thread provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of another thread structure and a cylindrical mating thread provided in an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of another thread structure and a cylindrical thread provided in an embodiment of the present invention.

[0031] The following labels are shown in the attached diagram:

[0032] 1. Conical thread section; 2. Cylindrical thread section; 3. Cylindrical mating thread; 4. Mating thread section; 5. Adjusting thread section. Detailed Implementation

[0033] This invention discloses a threaded structure to effectively solve the problem that the relative circumferential position of the threaded structure with the corresponding mating thread cannot be effectively adjusted when the threaded structure is locked.

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figures 1-5 , Figure 1 A schematic diagram of a threaded structure provided in an embodiment of the present invention; Figure 2 A schematic diagram of another threaded structure provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of a threaded structure and a cylindrical mating thread provided in an embodiment of the present invention; Figure 4This is a schematic diagram of another thread structure and a cylindrical mating thread provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of another thread structure and a cylindrical thread provided in an embodiment of the present invention.

[0036] In some specific embodiments, this embodiment provides a threaded structure, which can be an external thread or an internal thread.

[0037] Specifically, the threaded structure includes both a tapered thread section 1 and a cylindrical thread section 2. The tapered thread section 1 refers to the thread formed on a tapered cylinder, with one end being the large end and the other the small end, the diameter of the small end being smaller than the diameter of the large end. The cylindrical thread section 2 refers to the thread formed on a cylinder. The teeth of the threads on both the cylindrical thread section 2 and the tapered thread section 1 can be triangular or trapezoidal, and can be standard tooth profiles.

[0038] In some embodiments, the cylindrical thread segment 2 and the small end of the tapered thread segment 1 are threadedly connected to form an integral and continuous thread, allowing them to be fitted with the same cylindrical mating thread 3 for continuous screwing. Since the cylindrical thread segment 2 is connected to the small end of the tapered thread segment 1, the small end of the tapered thread segment 1 can have the same diameter as the cylindrical thread segment 2. When the thread structure is used as an external thread, and when it is fitted with the same cylindrical internal thread (i.e., one of the aforementioned cylindrical mating threads 3), generally the cylindrical thread segment 2 first enters the cylindrical internal thread and engages. Then, the thread structure continues to rotate relative to the cylindrical internal thread, and the tapered thread segment 1 then enters the cylindrical internal thread. As the diameter of the entered external thread portion gradually increases until it can no longer be screwed in, the teeth of the tapered thread segment 1 will abut against the teeth of the cylindrical internal thread.

[0039] There are generally several situations at this time, such as Figure 3 As shown, at this point, the thread structure, from the cylindrical thread section 2 to the conical thread section 1, has the same thread pitch at all points. When tightening, there is a section of teeth on the conical thread section 1 that abuts against the corresponding teeth on both sides of the cylindrical internal thread. At this point, the teeth on the conical thread section 1 near the larger section will form an interference fit with the tooth groove of the cylindrical internal thread, while the teeth on the conical thread section 1 near the smaller section, as well as the teeth on the cylindrical thread section 2, will form gaps with the corresponding tooth groove sidewalls.

[0040] It can also be as shown in the appendix. Figure 4 , 5 As shown, regarding Figure 4 , Figure 5 The cooperation relationships within are described in detail below.

[0041] In some embodiments, both the tapered thread segment 1 and the cylindrical thread segment 2 include mating thread portions 4 with equal pitches. That is, both the tapered thread segment 1 and the cylindrical thread segment 2 include mating thread portions 4, and the mating thread portions 4 of the tapered thread segment 1 and the cylindrical thread segment 2 have equal pitches. In use, the pitch of the cylindrical mating thread 3 is generally made equal to the pitch of the mating thread portions 4. For example... Figure 3 As shown, each part of the conical thread section 1 and each part of the cylindrical thread section 2, as well as the joints between them, are all the aforementioned mating threaded parts 4.

[0042] In some embodiments, the pitch of the section of thread in the conical thread segment 1 near the cylindrical thread segment 2 and / or the pitch of the section of thread in the cylindrical thread segment 2 near the conical thread segment 1 is increased or decreased compared to the mating thread portion 4. That is, the thread structure has an adjusting thread segment, the pitch of which is increased or decreased compared to the pitch of the mating thread. This adjusting thread segment can be a section of thread in the conical thread segment 1 near the cylindrical thread segment 2, or a section of thread in the cylindrical thread segment 2 near the conical thread segment 1, or both sections can have this adjusting thread segment at their connection points. Of course, the increase or decrease is less than the mating clearance, and preferably not greater than half of the mating clearance. The mating clearance can refer to the maximum possible clearance between the teeth when the cylindrical thread segment 2 meshes with the aforementioned cylindrical mating thread 3; the specific value is determined without changing the mating relationship.

[0043] In some embodiments, as shown in the appendix Figure 4 As shown, after adding the aforementioned adjusting thread section, during initial locking, the two sides of the teeth of the adjusting thread section located on the conical thread section 1 abut against the two sides of the tooth groove of the cylindrical mating thread 3. At this time, the symmetry line of the teeth of the adjusting thread section is aligned with the symmetry line of the tooth groove of the cylindrical mating thread 3. However, due to the increase in the pitch of the adjusting thread section, the symmetry lines of the teeth of the mating thread portions 4 located on the cylindrical thread section 2 and the conical thread section 1, respectively, are shifted from the corresponding symmetry lines of the tooth grooves of the cylindrical mating thread 3, as shown in the attached figure. Figure 4 As shown, the left side of the adjusting thread section is shifted to the left, while the right side is shifted to the right. Especially for the mating thread 4 of the tapered thread section 1, since it is in an offset state, there is still room for movement on the side with larger clearance. When the torque increases, and permissible elastic deformation and / or plastic deformation occurs, the thread structure can continue to rotate, thereby adjusting the angle.

[0044] In some embodiments, as shown in the appendix Figure 5 As shown, after adding the aforementioned adjusting thread section, during initial locking, due to the relative relationship between the mating thread portion 4 of the cylindrical thread section 2 and the mating thread portion 4 of the tapered thread section 1... Figure 3The offset of the thread structure causes the mating thread portion 4 on the cylindrical thread segment 2 and the mating thread portion 4 on the conical thread segment 1 to be offset in opposite directions relative to the corresponding cylindrical mating thread 3 tooth groove, so as to abut against the tooth groove wall on the opposite side, thereby achieving initial locking. The side that is close to each other has a large gap, which allows the thread structure to continue to rotate when the torque increases and allow elastic deformation and / or plastic deformation occurs, thereby adjusting the angle.

[0045] In some embodiments, when both the cylindrical thread segment 2 and the tapered thread segment 1 are engaged with the cylindrical mating thread 3 during use, they are respectively engaged with different thread portions of the cylindrical mating thread 3. During tightening, because at least one of the cylindrical thread segment 2 and the tapered thread segment 1 approaches each other, a change in pitch occurs, resulting in at least the following: Figure 4 , 5 A specific meshing relationship is proposed, such that during initial engagement, a portion of the threads in the tapered thread segment 1, near the major diameter section, are no longer centered within the tooth groove of the cylindrical mating thread 3, but rather offset. At this point, the torque can be further increased to cause adaptive deformation of the thread structure and / or the cylindrical mating thread 3, allowing the thread structure to continue screwing in. This, in turn, adjusts the angular positional relationship between the thread structure and the cylindrical mating thread 3 to meet predetermined positional requirements. In summary, this thread structure effectively solves the problem of the inability to effectively adjust the circumferential relative positional relationship between the thread structure and the corresponding mating threads during locking.

[0046] In some embodiments, as shown in the appendix Figure 1 As shown, compared to the mating thread portion 4 of the conical thread segment 1, the thread teeth or tooth grooves of the section of the conical thread segment 1 near the cylindrical thread segment 2 can be widened to obtain the aforementioned adjusting thread segment. Specifically, at the starting point of the small end teeth of the conical thread segment 1, while keeping the width between the tooth grooves constant, the width of the teeth can be gradually increased compared to the initial value, and then gradually decreased back to the initial value, thus forming the aforementioned adjusting thread segment. The width of the subsequent teeth of the conical thread segment 1 remains at the initial value, thus obtaining the aforementioned mating thread portion 4. The tooth widths of the cylindrical thread segment 2 are all at the initial value, therefore all are mating thread portions 4.

[0047] In some embodiments, the pitch at the junction of the tapered thread section 1 and the cylindrical thread section 2 is larger than the pitch of the mating thread portion 4, and the tooth width of the mating thread portion 4 of the tapered thread section 1 is equal to the tooth width of the mating thread portion 4 of the cylindrical thread section 2.

[0048] Specifically, at the connection point, the helix angle of the thread on the adjusting thread section can be formed, gradually increasing from one end to the other compared to the thread helix angle of the mating thread 4, and then gradually decreasing, in order to connect with the subsequent mating thread 4.

[0049] In some embodiments, as shown in the appendix Figure 2 As shown, the pitch between the threads on the conical thread section 1 and the pitch between the threads on the cylindrical thread section 2 are equal. The tooth width of the conical thread section 1 is smaller than the tooth width of the cylindrical thread section 2, so that the pitch between adjacent threads at the junction of the conical thread section 1 and the cylindrical thread section 2 is larger than the pitch of the mating thread section 4. Of course, the tooth width of the conical thread section 1 in contact with the tooth of the cylindrical thread section 2 can gradually transition, that is, gradually increase from small to large.

[0050] When performing unilateral cutting, the starting point of the teeth in the conical thread segment 1 can be gradually and continuously increased in cutting depth over a certain distance to form the teeth of the adjusting thread portion 5, and then this cutting depth can be maintained to continue cutting. Of course, the starting point of cutting can also be from the teeth of the cylindrical thread segment 2, so that at least a portion of the adjusting thread portion 5 is located in the cylindrical thread segment 2.

[0051] In some embodiments, as shown in the appendix Figure 1 , 2 As shown, both the tapered thread segment 1 and the cylindrical thread segment 2 can be external threads. Correspondingly, the tapered thread segment 1 can have a large section with a relief groove to facilitate thread machining, while a threaded head is located on the side of the relief groove away from the tapered thread segment 1.

[0052] Based on the threaded structures provided in the above embodiments, the present invention also provides a threaded connection pair, which includes a first component and a second component having a cylindrical mating thread 3, including any of the threaded structures in the above embodiments. Both the tapered thread section 1 and the cylindrical thread section 2 of the threaded structure are mated with the cylindrical mating thread 3, and the pitch of the mating thread portion 4 of the threaded structure is equal to the pitch of the cylindrical mating thread 3. Since this threaded connection pair adopts the threaded structure in the above embodiments, the beneficial effects of this threaded connection pair are explained in the above embodiments.

[0053] Among them, the cylindrical mating thread 3 can be the internal thread in the threaded hole, while the corresponding thread structure is the external thread on the screw.

[0054] Based on the threaded structures provided in the above embodiments, the present invention also provides a method for manufacturing a stud that mates with an internal cylindrical thread, the method comprising the following steps:

[0055] The driving machining cylinder rotates relative to the tool in a preset direction and at a preset speed around the axis, and translates relative to the tool along the axis at a first speed at a preset distance, so that the tool processes the front section of the thread;

[0056] The driving machining column rotates uniformly around the axis relative to the tool in the preset direction and at the preset rotation speed, and translates relative to the tool along the axis at a preset distance at a second speed not equal to the first speed, so that the tool processes the intermediate section of the thread;

[0057] The driving machining cylinder rotates uniformly around the axis relative to the tool in the preset direction and at the preset speed, and translates relative to the tool along the axis at the first speed for a preset distance, so that the tool processes the rear thread, one of the front thread and the rear thread is a cylindrical thread and the other is a tapered thread.

[0058] Since this method for manufacturing studs that fit into internal cylindrical threads can be used to manufacture the threaded structures in some of the above embodiments, please refer to the above embodiments for the beneficial effects of this method for manufacturing studs that fit into internal cylindrical threads.

[0059] Based on the threaded structures provided in the above embodiments, the present invention also provides a method for manufacturing a stud that mates with an internal cylindrical thread, the method comprising the following steps:

[0060] A stud with a tapered thread section 1 and a cylindrical thread section 2 is obtained, wherein the cylindrical thread section 2 is threadedly connected to the small end of the tapered thread section 1, and the thread pitch of the tapered thread section 1, the thread pitch of the cylindrical thread section 2, and the thread pitch at the connection are all equal.

[0061] The tapered thread section 1 is cut on one side.

[0062] Since this method for manufacturing studs that fit into internal cylindrical threads can be used to manufacture the threaded structures in some of the above embodiments, please refer to the above embodiments for the beneficial effects of this method for manufacturing studs that fit into internal cylindrical threads.

[0063] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A threaded connection pair, comprising a first component and a second component having a cylindrical mating thread, wherein the external thread of the first component is a threaded structure, characterized in that, The threaded structure includes a tapered thread segment and a cylindrical thread segment that connects to the small end thread of the tapered thread segment; both the tapered thread segment and the cylindrical thread segment include mating thread portions with equal pitch to mate with the cylindrical mating thread; the pitch of the thread segment of the tapered thread segment near the cylindrical thread segment and / or the pitch of the thread segment of the cylindrical thread segment near the tapered thread segment is increased or decreased compared to the pitch of the mating thread portion; the pitch of the mating thread portion of the threaded structure is equal to the pitch of the cylindrical mating thread.

2. The threaded connection pair according to claim 1, characterized in that, Compared to the mating thread portion of the conical thread segment, the thread teeth or grooves of the conical thread segment near the cylindrical thread segment are widened.

3. The threaded connection pair according to claim 1, characterized in that, The pitch at the junction of the tapered thread section and the cylindrical thread section is larger than the pitch of the mating thread section.

4. The threaded connection pair according to claim 1, characterized in that, The pitch between the threads on the conical thread section and the pitch between the threads on the cylindrical thread section are equal; the tooth width of the conical thread section is smaller than the tooth width of the cylindrical thread section, so that the pitch between adjacent threads at the junction of the conical thread section and the cylindrical thread section is larger than the pitch of the mating thread portion.

5. The threaded connection pair according to any one of claims 1-4, characterized in that, Both the tapered thread section and the cylindrical thread section are external threads.

6. The threaded connection pair according to claim 5, characterized in that, The large-diameter section of the tapered thread segment has a relief groove.

7. A method for manufacturing a stud that fits into an internal thread of a cylinder, characterized in that, The application to the threaded connection pair according to any one of claims 1 to 6 includes the following steps: The driving machining cylinder rotates relative to the tool in a preset direction and at a preset speed around the axis, and translates relative to the tool along the axis at a first speed at a preset distance, so that the tool processes the front section of the thread; The driving machining column rotates uniformly around the axis relative to the tool in the preset direction and at the preset rotation speed, and translates relative to the tool along the axis at a preset distance at a second speed not equal to the first speed, so that the tool processes the intermediate section of the thread; The driving machining cylinder rotates uniformly around the axis relative to the tool in the preset direction and at the preset speed, and translates relative to the tool along the axis at the first speed for a preset distance, so that the tool processes the rear thread, one of the front thread and the rear thread is a cylindrical thread and the other is a tapered thread.

8. A method for manufacturing a stud that fits into an internal thread of a cylinder, characterized in that, The application to the threaded connection pair according to any one of claims 1 to 6 includes the following steps: A stud with a tapered thread section and a cylindrical thread section is obtained, wherein the cylindrical thread section is threadedly connected to the small end of the tapered thread section, and the thread pitch of the tapered thread section, the thread pitch of the cylindrical thread section, and the thread pitch at the connection are all equal. The tapered thread section is cut on one side.

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