Parallel-tapered integral threaded joint for rebar connections

Abstract

In a threaded connection structure between an internally threaded body and an externally threaded body for connecting reinforcing bars, the internally threaded body includes a parallel internally threaded portion formed with parallel threads on an inner diameter thereof and a parallel-taper integrated internally threaded portion formed integrally at one end of the parallel internally threaded portion with a tapered internally threaded portion whose inner diameter narrows, and the externally threaded body includes a parallel externally threaded portion formed with parallel threads on an outer diameter thereof and a parallel-taper integrated externally threaded portion formed integrally at one end of the parallel internally threaded portion with a tapered internally threaded portion whose outer diameter narrows, and the internal diameter (minor diameter) of the parallel internally threaded portion is larger than the maximum internal diameter of the tapered internally threaded portion, and the external diameter (major diameter) of the parallel internally threaded portion is The parallel-taper integrated threaded connection structure for connecting reinforcing bars is provided, in which the inner diameter of the parallel female thread portion is larger than the maximum outer diameter of the tapered male thread portion, and thread discontinuities are formed between the parallel female thread portion and the tapered female thread portion and between the parallel male thread portion and the tapered male thread portion, respectively, and the inner diameter of the parallel female thread portion is larger than the maximum outer diameter of the tapered male thread portion.

Description

[Technical Field]

[0001] The present invention relates to a parallel-taper integrated threaded connection structure for connecting rebars, and more particularly, to an invention in which, when a female-threaded body and a male-threaded body are threadedly connected, a female-male parallel thread portion and a female-male tapered thread portion are simultaneously connected in a parallel-taper manner, and this effect is utilized to reduce the number of connection rotations, making threaded connection possible.The invention also relates to an invention in which the guiding effect of the tapered structure eliminates the need to align the start point of the spiral, and reduces the phenomenon of loosening after connection. [Background technology]

[0002] In the conventional method for connecting male and female parallel threads for connecting rebars, the number of rotations required to complete the connection is equal to the number of threads, so that the threads must be rotated until all threads are fully connected, and the time required for the connection increases with the number of threads. In addition, the axial centers and the starting points of the helix must be aligned when initially connecting the male and female threads.

[0003] Referring to Figure 15 of the related art, Patent Document 1 (US Patent No. 3,415,552) discloses a metal reinforcing bar for ties with a coupling sleeve having a thread formed thereon. The tapered reinforcing bar end and coupling sleeve disclosed in the patent are configured to include a connection between male and female threads using a tapered thread.

[0004] When we look closely at the method of joining using only male and female tapered threads, we see that the number of rotations required to complete the joining is reduced compared to when joining female and male parallel threads, allowing for quick joining, and the tapered structure allows for a guiding action when inserting the male threads. However, due to the limitations of the tapered structure at the start of thread joining, the joining between the threads is incomplete, and after joining is complete, there is a risk of axial flow due to insufficient strength, or the threads may loosen when vibrations occur or come out even with a smaller tensile force than with parallel threads.

[0005] Also, referring to drawing X1 in Figure 4, in a conventional example in which a tapered thread and a parallel thread are simply combined, when the tapered thread is positioned at the end of the rebar and is positioned closer to the end than the parallel thread, the maximum outer diameter of the tapered thread and the outer diameter of the parallel thread are the same, causing interference between the female thread 34 and the male thread 35 during insertion. Therefore, the tapered thread could not be inserted deeply to be coupled without thread rotation, which resulted in the disadvantage that the number of rotations required to complete coupling was less than that of a parallel thread but more than that of a tapered thread, and it was also difficult to form a thread.

[0006] 16, a rebar connection structure is disclosed in Patent No. 10-0439628, in which the parallel threads are located at the end of the rebar and are positioned closer to the end than the tapered threads. In this rebar connection structure, a rebar is formed with a connecting socket having female threads formed symmetrically on both sides, and a rebar having male threads formed at its end and threadedly coupled to the end of the connecting socket. The female threads 11 of the connecting socket 10 have a tapered, drawn female thread 11a on the outside, and a horizontal, tension female thread 11b formed continuously on the inside of the drawn female thread 11a. The end of the male threads 21 of the rebar 20 has a horizontal, tension male thread 21b that is threadedly coupled to the tension female thread 11b of the connecting socket 10, and the tension male thread 21b has a tapered, drawn male thread 21a that is threadedly coupled to the drawn female thread 11a of the connecting socket 10.

[0007] However, when one looks closely at this configuration, the thread between the tension female thread portion 11b and the tension male thread portion 21b is a parallel thread portion, so the number of rotations required for coupling is inevitably greater than that of a tapered thread portion. In fact, when fastening the connecting socket and the reinforcing bar, it is thought that the axes of the male and female parallel thread portions should be aligned even after the reinforcing bar is inserted into the connecting socket, and the screw coupling operation should be carried out.

[0008] In addition, since the connection between the parallel thread portions is first established and only after the connection up to the last parallel thread is completed, the connection between the tapered thread portions is realized later, it is believed that the structure ultimately does not allow for simultaneous connection of the parallel thread and the tapered thread. Here, an invention is disclosed that utilizes the advantages of parallel threads and tapered threads while solving the problems associated with each of the parallel threads and tapered threads. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] US Patent 3415552 Summary of the Invention [Problem to be solved by the invention]

[0010] The object of the present invention is to form a parallel female thread portion and a parallel male thread portion with any diameter standard, without being concerned with the maximum inner diameter of a tapered female thread portion or the maximum outer diameter of a tapered male thread portion. Another object of the present invention is to allow a tapered screw to be inserted deeply even without screw rotation. Another object of the present invention is to reduce the number of coupling rotations while ensuring that all parallel tapered threads are coupled without leakage. Another object is to simultaneously couple the parallel thread portion and the tapered thread portion. Another object is to enable the connection between the threads to be locked without the need for a lock nut. Another object is to reduce distortion in straightness compared to connections using only tapered threads. Another object is to generate a guiding effect when inserting the male threaded body. Another object is to enable quick screw connection. Another object is to minimize the phenomenon of loosening of the screws. [Means for solving the problem]

[0011] The present invention, which has been devised to achieve the above object, provides a threaded connection structure between an internally threaded body and an externally threaded body for connecting reinforcing bars, wherein the internally threaded body includes a parallel internally threaded portion formed with parallel threads on its inner diameter, and a parallel-tapered integrated internally threaded portion formed integrally with a tapered internally threaded portion whose inner diameter narrows at one end of the internally threaded portion; the externally threaded body includes a parallel internally threaded portion formed with parallel threads on its outer diameter, and a parallel-tapered integrated internally threaded portion formed integrally with a tapered internally threaded portion whose outer diameter narrows at one end of the internally threaded portion; the internal diameter of the parallel internally threaded portion is larger than the maximum internal diameter of the tapered internally threaded portion, and the external diameter of the parallel internally threaded portion is larger than the maximum external diameter of the tapered internally threaded portion; and thread discontinuities are formed between the parallel internally threaded portion and the tapered internally threaded portion, and between the parallel internally threaded portion and the tapered internally threaded portion, respectively, and the internal diameter of the parallel internally threaded portion is larger than the maximum external diameter of the tapered internally threaded portion.

[0012] The female-threaded body and the male-threaded body are characterized in that they are temporarily joined so that the tapered male thread portion of the male-threaded body is completely inserted into the female-threaded body without any thread rotation. The female-threaded body and the male-threaded body are characterized in that they are shaped to be temporarily joined so that both the female-male tapered thread portions and the female-male parallel thread portions can be threadably joined.

[0013] The male or female threaded body is integrated with the reinforcing bar, and the male or female threaded body is integrated with one end of the reinforcing bar, male threaded bodies are integrated with both ends of the reinforcing bar, female threaded bodies are integrated with both ends of the reinforcing bar, or male and female threaded bodies are integrated with both ends of the reinforcing bar, respectively. The externally threaded body or the internally threaded body is friction-welded to be integrated with the reinforcing bar.

[0014] When male threaded bodies are integrated with both ends of the reinforcing bar, the rotation directions of the threads of the male threaded bodies at both ends are the same or opposite to each other; when female threaded bodies are integrated with both ends of the reinforcing bar, the rotation directions of the threads of the female threaded bodies at both ends are the same or opposite to each other; and when a male threaded body and a female threaded body are integrated with both ends of the reinforcing bar, respectively, the rotation directions of the threads of the female threaded bodies at both ends and the male threaded body are the same or opposite to each other. The parallel-taper integral male thread portion is characterized in that it is directly formed on the reinforcing bar by thread machining the end of the reinforcing bar.

[0015] In a threaded coupling structure between an internally threaded body and an externally threaded body for connecting reinforcing bars, the internally threaded body is a reinforcing bar coupler in which a parallel female thread portion formed with parallel threads on the inner diameter and a parallel-tapered integrated female thread portion formed integrally with a tapered female thread portion whose inner diameter narrows at one end of the parallel female thread portion are formed on the same axis with the tapered thread directions facing each other; and the externally threaded body is a reinforcing bar formed with a parallel male thread portion formed with parallel threads on the outer diameter and a parallel-tapered integrated male thread portion formed integrally with a tapered male thread portion whose outer diameter narrows at one end of the parallel male thread portion, wherein thread discontinuities are formed between the parallel female thread portion and the tapered female thread portion and between the parallel male thread portion and the tapered male thread portion, and the internal diameter of the parallel female thread portion is larger than the maximum external diameter of the tapered male thread portion.

[0016] The reinforcing bar coupler is characterized in that the threads of the parallel-tapered integral female screw portions facing each other have the same or opposite rotation directions. [Effects of the Invention]

[0017] The present invention has the effect of forming thread discontinuities between the parallel female thread portion and the tapered female thread portion, and between the parallel male thread portion and the tapered male thread portion, thereby making it possible to form the parallel female thread portion and the parallel male thread portion to any diameter standard, without having to be concerned with the maximum inner diameter of the tapered female thread portion or the maximum outer diameter of the tapered male thread portion.

[0018] In addition, the inner diameter of the parallel female thread portion is formed larger than the maximum outer diameter of the tapered male thread portion, which has the effect of allowing the tapered thread portion of the male threaded body to be completely inserted into the female threaded body without any screw rotation and temporarily joined.

[0019] In addition, when the female-threaded body and the male-threaded body are rotated to couple together, the female-male parallel thread portion and the female-male tapered thread portion are simultaneously coupled together, which has the effect of reducing the number of coupling rotations while enabling a configuration in which all parallel-tapered threads are coupled together without coming off.

[0020] Furthermore, the tapered thread and the parallel thread form threads that interlock with each other, which has the effect of simultaneously joining the parallel thread portion and the tapered thread portion.

[0021] In addition, when the connection is completed, the parallel thread portion and the tapered thread portion are mutually squeezed, so that the connection between the threads can be locked without a lock nut.

[0022] Furthermore, after joining, the female-threaded body and the male-threaded body are joined together through a connection that includes a connection using a parallel thread portion, so that the straightness of the parallel thread portion can be maintained, and there is an effect of even less straightness distortion than with a connection using only tapered threads.

[0023] Furthermore, when the male-threaded body is inserted into the female-threaded body, the axis is automatically aligned by the angle of the taper, which has the effect of providing a guiding function when the male-threaded body is inserted.

[0024] In addition, the work of aligning the axes, which must be done every time a rebar is joined, can be omitted, thereby improving the efficiency of the rebar joining work.

[0025] Furthermore, when inserting a male-threaded body into a female-threaded body, there is no need to perform a separate operation to align the thread start point, which has the effect of enabling quick screw connection.

[0026] Furthermore, when the female-threaded body and male-threaded body are formed with a parallel-tapered integrated single-start thread, the parallel-tapered thread structure has the effect of ensuring a high joining speed similar to that of a multiple-start thread.

[0027] In addition, by reducing the lead angle of a single-start thread, there is an effect of minimizing the phenomenon of loosening of the thread. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a partial cross-sectional view of an embodiment of the present invention; [Figure 2] 1 is a view showing an internally threaded body having a parallel-taper integrated internal thread portion formed thereon. [Figure 3] 1 is a view showing a male-threaded body having a parallel-taper integral male thread portion formed thereon. [Figure 4] 10 is a diagram showing a difference in bonding depth when provisionally bonding in preparation for a conventional embodiment and an embodiment of the present invention. [Figure 5] 1 is a view showing a temporarily joined state according to the first embodiment. [Figure 6] 10 is a view showing a temporary coupling state according to a second embodiment. [Figure 7] 10 is a view showing a temporary coupling state according to a third embodiment. [Figure 8] 10 is a diagram showing a 0 rotation state after temporary coupling in the first embodiment. [Figure 9] 10 is a view showing a state where the first embodiment has been temporarily coupled and rotated once. [Figure 10] 10 is a view showing a state where two rotations have been made after temporary coupling in the first embodiment. [Figure 11] 10 is a diagram showing a state where the connector has been rotated three times after temporary coupling in the first embodiment. [Figure 12] 10 is a view showing a state where four rotations have been made after temporary coupling in the first embodiment. [Figure 13] 1 is a drawing showing a reinforcing bar, an internally threaded body, and an externally threaded body. [Figure 14] 1 is a diagram showing an embodiment of an internally threaded body having parallel-taper integral internal threads formed on both sides. [Figure 15] 1 is a diagram showing a conventional embodiment. [Figure 16] 1 is a diagram showing a conventional embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

[0029] The parallel-tapered integral screw connection structure for connecting reinforcing bars will be described in detail below. In this specification, a parallel thread refers to a thread in which the inner diameter or outer diameter of the thread is constant along the axial direction, and a tapered thread refers to a thread in which the inner diameter or outer diameter of the thread increases or decreases along the axial direction, forming a taper angle. Furthermore, unless otherwise specified, "comprising" a certain element does not mean excluding other elements, but rather means that other elements may be further included.

[0030] 1 to 3, the parallel-taper integral threaded joint structure of the present invention includes an internally threaded body 20, an externally threaded body 30, a parallel-taper integral internally threaded portion 21, and a parallel-taper integral externally threaded portion 31.

[0031] The female-threaded body 20 includes a parallel female-threaded portion P1 formed with parallel threads on the inner diameter, and a parallel-tapered integrated female-threaded portion 21 in which a tapered female-threaded portion T1 whose inner diameter narrows is integrally formed at one end of the parallel female-threaded portion P1.

[0032] The internally threaded body 20 has a parallel internal thread portion P1 and a tapered internal thread portion T1 formed on the inner diameter thereof inward, so that the tapered internal thread portion T1 is positioned more inward than the parallel internal thread portion P1.

[0033] The male-threaded body 30 includes a parallel male-threaded portion P2 formed with parallel threads on the outer diameter, and a parallel-tapered integrated male-threaded portion 31 integrally formed with a tapered male-threaded portion T2 whose outer diameter narrows at one end of the parallel male-threaded portion P2.

[0034] The tapered threads T1 and T2 and parallel threads P1 and P2 are formed to mutually corresponding standards for threaded connection, and are all threaded together in a male-female interlocking structure.

[0035] For this reason, the minor diameter (DP1) of the parallel female thread portion P1 is formed to be larger than the maximum minor diameter DT1 of the tapered female thread portion T1.

[0036] That is, the tapered female thread portion T1 is formed so that the inner diameter gradually increases toward the parallel female thread portion P1, but the maximum inner diameter DT1 of the tapered female thread portion T1 is formed smaller than the inner diameter DP1 of the parallel female thread portion P1.

[0037] The major diameter (DP2) of the parallel male thread portion P2 is larger than the maximum major diameter DT2 of the tapered male thread portion T2.

[0038] That is, the outer diameter of the tapered male thread portion T2 is formed so as to gradually increase in the direction of the parallel male thread portion P2, but the maximum outer diameter DT2 of the tapered male thread portion T2 is formed smaller than the outer diameter DP2 of the parallel male thread portion P2.

[0039] This allows the tapered threads T1, T2 and the parallel threads P1, P2 to all form mating threads.

[0040] Furthermore, thread discontinuities 23, 33 are formed between the parallel female thread portion P1 and the tapered female thread portion T1, and between the parallel male thread portion P2 and the tapered male thread portion T2, respectively. The discontinuous portions 23, 33 may have various shapes and methods as long as the threads are discontinuous.

[0041] For example, a recessed portion can be machined to form a circumferentially recessed band, which results in a continuous tapered thread portion-recess portion-parallel thread portion T1-23-P1, T2-33-P2 configuration. As a result, the threads of the tapered thread portions T1 and T2 are not continuous.

[0042] However, it is not necessary to form the recess as described above in order to discontinuously form the thread, and various configurations for forming discontinuous threads are possible.

[0043] If the threads are discontinuous, thread machining is easy, and the parallel female thread portion P1 and the parallel male thread portion P2 can be formed to any diameter standard without having to consider the maximum inner diameter DT1 of the tapered female thread portion T1 or the maximum outer diameter DT2 of the tapered male thread portion.

[0044] This allows the effective cross-sectional areas of the tapered thread portions T1, T2 and the parallel thread portions P1, P2 to be added together, providing resistance to tensile forces and the like.

[0045] For efficient and quick screw coupling work, the inner diameter DT1 of the parallel female thread portion P1 is formed larger than the maximum outer diameter DT2 of the tapered male thread portion.

[0046] With this configuration, unwanted interference between the threads can be prevented at the source during the screw coupling operation.

[0047] As a result, when the female-threaded body 20 and the male-threaded body 30 are rotated to couple together, the female-male parallel thread portions P1 and P2 and the female-male tapered thread portions T1 and T2 are simultaneously coupled together. This action reduces the number of coupling rotations while enabling a configuration in which all parallel-tapered threads are coupled together without coming off.

[0048] In other words, the tapered threads and parallel threads are all configured to form mating threads, which has the effect of simultaneously connecting the male and female parallel thread portions P1, P2 and the male and female tapered thread portions T1, T2.

[0049] Furthermore, when the connection is complete, the tapered threads T1, T2 and the parallel threads P1, P2 are mutually squeezed, locking the connection between the threads without the need for a lock nut. This allows for a self-locking action and eliminates initial slippage at the rebar connection.

[0050] After being joined, the female-threaded body 20 and the male-threaded body 30 include a connection by the parallel thread portions P1 and P2, and can maintain straightness due to the parallel thread portions P1 and P2, which is thought to have the effect of reducing straightness distortion compared to a connection using only the tapered thread portions T1 and T2.

[0051] The internally threaded body 20 and the externally threaded body 30 are made of a metal material.

[0052] Referring to drawing X1 in Figure 4, in the case of a conventional embodiment in which a tapered thread and a parallel thread are simply combined, when the maximum outer diameter of the tapered thread and the outer diameter of the parallel thread are the same, interference occurs between the female thread 35 and the male thread 34 36. This limits the provisional coupling depth D1, and the tapered thread cannot be inserted deeply enough to achieve provisional coupling without thread rotation.

[0053] However, according to the present invention, as shown in drawing X2 of Figure 4, the inner diameter of the parallel female thread portion of the female-threaded body and the male-threaded body is formed larger than the maximum outer diameter of the tapered male thread portion, and when the temporary coupling is completed, the tapered thread portions can be in contact with each other 37 and the parallel thread portions can be spaced apart 38. As a result, since the temporary coupling depth is determined by whether or not the tapered thread portion and the parallel thread portion are in contact with each other, the temporary coupling depth in drawing X2 is deeper than that in drawing X1.

[0054] That is, the male-threaded body can be inserted into the female-threaded body without thread rotation to the starting point of the connection between the tapered threads of the female and male tapered thread portions (Fig. 5), or the starting point of the simultaneous connection between the tapered threads of the female and male tapered thread portions and the parallel threads of the female and male parallel thread portions (Fig. 6), or the starting point of the connection between the parallel threads of the female and male parallel thread portions (Fig. 7), and provisional connection can be performed D2. Here, the connection depth D2 during provisional connection can be increased (D2>D1).

[0055] As described above, when the inner diameter DP1 of the parallel female thread portion P1 is formed larger than the maximum inner diameter DT1 of the tapered female thread portion T1, the tapered male thread portion T2 of the male threaded body 30 is configured to be temporarily coupled so as to be completely inserted into the female threaded body 21 without any thread rotation.

[0056] In other words, the tapered male thread portion T2 of the male threaded body 30 is completely inserted into the inside of the female threaded body 21, and provisional coupling can be achieved deep enough to not be exposed to the outside.

[0057] This makes it possible to omit the axial alignment work that must be performed every time a reinforcing bar is joined, when the initial joining occurs, thereby improving the efficiency of the reinforcing bar joining work.

[0058] Referring to FIG. 5, first, as a first embodiment, a female-threaded body 202 and a male-threaded body 203 can be temporarily joined such that the female and male tapered thread portions are in contact with each other 200 and the female and male parallel thread portions are spaced apart 201.

[0059] For example, when the threads are single-start threads, a preferred embodiment is one in which the male and female parallel threads begin to couple when the male and female tapered threads are rotated 0.5 turns.

[0060] Therefore, if one pitch is 2.5, when the female and male tapered thread portions come into contact with each other, the separation distance 204 between the joining start points of the female and male parallel thread portions is 1.25 mm, which is half of 2.5 mm.

[0061] There is no need to search for the starting point of the connection between the male and female tapered threads. The male and female threads naturally align during the rotation process.

[0062] As a result, when the male threaded body 203 is inserted into the female threaded body 202, the axis is automatically aligned by the angle of the taper, which has the effect of providing a guiding function when the male threaded body 203 is inserted.

[0063] This eliminates the need for a separate thread start point alignment process, allowing for quick screw connection.

[0064] In the case of parallel threads, the thread start point must be aligned in order for the initial thread connection to occur, but the present invention does not require this starting point alignment even though it is an invention that includes thread connection between parallel threads in its configuration.

[0065] After the temporary joining, when rotation begins in the screw direction, joining between the parallel threads begins, and immediately thereafter joining between the tapered threads also begins.

[0066] Referring to FIG. 6, as a second embodiment, a female-threaded body 302 and a male-threaded body 303 can be temporarily joined so that the female and male tapered thread portions and the female and male parallel thread portions are simultaneously in contact 300, 301.

[0067] In this embodiment, when the tapered thread portion and the parallel thread portion are provisionally coupled, they are all in contact 300, 301, so when rotated in the rotational direction, both the male and female tapered threads and the male and female parallel threads begin to couple together.

[0068] Referring to FIG. 7, in a third embodiment, the female-threaded body 402 and the male-threaded body 403 can be temporarily joined such that the female and male tapered thread portions are spaced apart 400 from each other and the female and male parallel thread portions are in contact 401 with each other.

[0069] In the case of such an embodiment, when rotation in the thread direction is started after provisional coupling, coupling between the parallel threads begins, and immediately thereafter coupling between the tapered threads also begins.

[0070] In either case, once the threads are temporarily joined and the threads are started to rotate in the screw direction, the tapered threads and parallel threads are all joined.

[0071] In this way, the female-threaded body and the male-threaded body are configured to be temporarily joined so that the female-male tapered thread portions and the female-male parallel thread portions can all be threadedly joined.

[0072] The internally threaded body and the externally threaded body may be single-start or multiple-start threads.

[0073] A single thread can advance by about the pitch in one rotation, making quick connection difficult, but as the lead angle of the thread decreases, loosening of the thread occurs less frequently when vibration or tension in the axial direction occurs.

[0074] Double thread screws can advance twice the pitch per revolution, allowing for quick connection, but as the lead angle of the screw increases, loosening of the screw can easily occur when vibration or tension in the axial direction occurs.

[0075] Also, triple threads allow for faster connection, but are more susceptible to loosening.

[0076] Preferably, when the female-threaded body and the male-threaded body are formed with a parallel-taper integrated single-start thread, the parallel-taper thread structure ensures the same high coupling speed as a multiple-start thread, while minimizing the loosening of the threads by reducing the lead angle of the single-start thread.

[0077] Furthermore, when even faster connection is required, the female-threaded body and the male-threaded body can be formed with multiple threads. The first embodiment will be described in more detail below.

[0078] 8 to 12, the internally threaded body 40 has a taper angle of 6° with respect to the axial direction and is a single-start thread. The tapered internal thread portion 42 has a pitch of 2.5 mm, a maximum inner diameter of 33.42 mm, and 18 tapered internal threads. The parallel internal thread portion 45 has a pitch of 2.5, an inner diameter of 36.78 mm, and 4 parallel internal threads.

[0079] The male-threaded body 41 has a taper angle of 6° relative to the axial direction and is a single-start thread. The tapered male-threaded portion 42 has a pitch of 2.5 mm, a maximum outer diameter of 35.51 mm, and 18 tapered male-thread threads. The parallel male-threaded portion 44 has a pitch of 2.5 mm, an outer diameter of 38.68 mm, and 4 parallel male-thread threads.

[0080] When the tapered male and female thread portions are in contact with each other in the provisionally joined state, the parallel female thread portion 45 and the parallel male thread portion 44 are spaced apart by 1.25 mm.

[0081] The inner diameter of the parallel female thread portion 45 is larger than the maximum outer diameter 35.51 mm of the tapered male thread portion 42 (36.78 mm > 35.51 mm), so the tapered male thread portion 42 does not interfere with the parallel female thread portion 45 when the male threaded body 41 is inserted.

[0082] When the male-threaded body 41 is accurately inserted into the female-threaded body 40 in the axial direction, the point where initial contact occurs is the coupling start point (MT) between the tapered female-threaded portion 42 and the tapered male-threaded portion 42 .

[0083] Up until this time, the parallel female thread portion 45 and the parallel male thread portion 44 are in a spaced apart state because they are in a temporary joined state.

[0084] Because the separation distance 48 is 1.25 mm, the initial engagement start between the parallel threads occurs after 0.5 revolutions of the male threaded body 41 .

[0085] The contact point (MT) is called the parallel thread 0 turn point (0 TURN).

[0086] Referring to FIG. 9, when the parallel threads are joined by one turn (1 TURN), the entire tapered threads are joined by about one-fourth of the total joining distance, and the parallel threads and tapered threads begin to join simultaneously.

[0087] Referring to FIG. 10, when parallel threads are joined by two turns (2 TURN), all tapered threads are joined by about two-quarters of the total joining distance. Referring to FIG. 11, in the case of a 3-turn parallel thread coupling, all of the tapered threads are threaded together for about three-quarters of the total coupling distance. Referring to FIG. 12, in the case of a 4-turn parallel thread coupling, all of the tapered threads are threaded together for about 4 / 4 of the total coupling distance, and the coupling is completed.

[0088] That is, each time the male threaded body 41 is rotated once, the male threaded body 41 advances by a pitch of about 2.5 mm, thereby joining the entire tapered threaded portions 42, 43 together, and the joining is completed after four rotations.

[0089] As a result, when the male threaded body 41 is rotated four times, the joining of a total of 22 threads, consisting of 18 (tapered threads) and 4 (parallel threads), is completed in one go.

[0090] When the parallel thread portions 44, 45 are joined, the tapered thread portions 42, 43 are all joined at once, so that all 22 single-start threads are joined with only four rotations (number of rotations: number of joining threads = 4:22).

[0091] Furthermore, when the tapered female thread portion 43, the tapered male thread portion 42, the parallel female thread portion 45, and the parallel male thread portion 44 are each formed with a double thread, the male thread body 41 advances by about 5 mm pitch per rotation, and all 22 threads can be fully coupled with only two rotations (number of rotations: number of coupled threads = 2:22).

[0092] In addition, the phase deviation between the spiral end point of the tapered female thread portion 43 and the spiral start point of the parallel female thread portion 45 and the phase deviation between the spiral end point of the tapered male thread portion 42 and the spiral start point of the parallel male thread portion 44 can be formed to correspond to each other.

[0093] That is, the phase deviations are mutually identical or can be processed to within a predetermined error range within which thread connection is possible.

[0094] Furthermore, the connection structure between the parallel-taper integrated female and male thread portions 46, 47 has the characteristic that the tapered thread structure and the parallel thread structure complement each other, so that it can withstand vibration and lateral force more effectively than a connection structure using only parallel threads or a connection structure using only tapered threads.

[0095] The taper angle, whether a single-start or multiple-start thread is used, pitch distance, number of tapered threads, number of parallel threads, maximum outer diameter of the tapered male thread portion 42 of the male-threaded body 41, outer diameter of the parallel male thread portion 44, maximum inner diameter of the tapered female thread portion 42 of the female-threaded body 40, and inner diameter of the parallel female thread portion 45 can be variously formed and implemented as needed.

[0096] The threads of the internally threaded body and the externally threaded body may have various shapes. For example, the cross-sectional shape may be polygonal, trapezoidal, sawtooth, or round. In particular, when a large force is required, the threads of the internally threaded body and the externally threaded body may be sawtooth or round.

[0097] Referring to FIG. 13, the male threaded body 101 or the female threaded body 102 may be integrated with one end 108 or both ends 105 of the reinforcing bar 105 .

[0098] That is, a male or female threaded body may be integrated with one end of the reinforcing bar, a male threaded body may be integrated with both ends of the reinforcing bar, a female threaded body may be integrated with both ends of the reinforcing bar, or a male threaded body and a female threaded body may be integrated with both ends of the reinforcing bar, respectively.

[0099] The externally threaded body 101 is a solid material.

[0100] For example, the solid male threaded body 101 is a solid male threaded body 101 for threaded connection, in which a thread is formed on a shaft portion and a peripheral surface of the shaft portion. The solid male threaded body for threaded connection is integrated with a rebar 105. For example, it can be integrated on the extension to the rebar 105 through various welding methods such as friction welding 106, stud welding, electron beam welding, laser welding, CO2 welding, argon welding, butt welding, and flash welding. When friction welding, the weld reinforcement can be removed after processing is completed.

[0101] The internally threaded body 102 is a body and an internally threaded body 102 that can be threaded together by forming a thread on the inner surface of the body.

[0102] The female threaded body 102 for threaded connection can be integrated with the rebar 105. For example, it can be integrated with the rebar 105 through various welding methods such as friction welding 107, stud welding, electron beam welding, laser welding, CO2 welding, argon welding, butt welding, and flash welding. When using friction welding, the welded reinforcement can be removed after processing is completed.

[0103] For example, the solid male threaded body 101 - rebar 105 - solid male threaded body 101, the solid male threaded body 101 - rebar 105 - female threaded body 102, and the female threaded body 102 - rebar 105 - female threaded body 102 can be integrated together.

[0104] In this case, the rotation directions of the threads between the members on both sides based on the reinforcing bar may be the same or opposite to each other.

[0105] That is, when male threaded bodies are integrated with both ends of the reinforcing bar, the rotation directions of the threads of the male threaded bodies may be the same or opposite to each other; when female threaded bodies are integrated with both ends of the reinforcing bar, the rotation directions of the threads of the female threaded bodies may be the same or opposite to each other; and when a male threaded body and a female threaded body are integrated with both ends of the reinforcing bar, respectively, the direction of the threads of the female threaded body and the rotation direction of the threads of the male threaded body may be the same or opposite to each other.

[0106] For example, if the threads are formed in opposite directions and male threads are integrated on both ends of the rebar, the left end will be a right-handed thread and the right end will be a left-handed thread, which allows for easy connection when connecting the rebars on both ends.

[0107] In addition, when the sizes of the members integrated with both ends of the reinforcing bar are different, different diameter connections are possible. That is, when an externally threaded body is integrated with both ends of the reinforcing bar, the sizes of the externally threaded body at both ends can be different, when an internally threaded body is integrated with both ends of the reinforcing bar, the sizes of the internally threaded body at both ends can be different, or when an externally threaded body and an internally threaded body are integrated with both ends of the reinforcing bar, the sizes of the externally threaded body and the internally threaded body at both ends can be different.

[0108] Here, for example, when reinforcing bar construction is being carried out from the bottom to the top, if it is necessary to connect reinforcing bars of different diameters, this can be accommodated using different diameter connectors.

[0109] Although not shown, various configurations are possible, such as forming a parallel-taper integrated male thread portion on only one side of the reinforcing bar and not connecting a separate member to the other side, or forming a parallel-taper integrated female thread portion on one side and connecting a fixing member to the other side.

[0110] In particular, the internally threaded body may have only one parallel-taper integrated internal thread portion, or may have multiple parallel-taper integrated internal thread portions, each of which has a tapered thread portion located on the inside and a parallel thread portion located on the outside.

[0111] Referring to FIG. 14, the female-threaded body 141 is formed with a pair of parallel-taper integrated female-threaded portions 143, and the pair of tapered female-threaded portions of the parallel-taper integrated female-threaded portions 143 are formed so that they face each other, forming a coupler that connects male-threaded bodies 142 from both sides.

[0112] That is, two parallel-taper integrated female thread portions 143 may be formed with their tapered thread directions facing each other. Reinforcing bars each having a parallel-taper integrated male thread portion 144 formed thereon may be connected to the opposing parallel-taper integrated female thread portions 143 by being screwed from both sides.

[0113] Here, the female threaded body 141 serves as a reinforcing bar coupler that connects the reinforcing bars of the male threaded body 142 from both sides.

[0114] When the female thread body 141 is used as a rebar coupler, the rotation directions of the threads of the parallel-tapered integral female thread portions 143 facing each other may be formed to be the same or opposite to each other as needed.

[0115] In addition, to form a parallel-taper integrated male thread portion, the end of the reinforcing bar can be directly cold swaged, finished and chamfered, and then threaded using a rolling device (flat die, rolling die, etc.), or a parallel-taper integrated male thread portion can be directly machined and formed on the end of the reinforcing bar by cold swaging followed by cutting thread machining.

[0116] The internally threaded body 141 may be formed with an anti-slip means for easy tool gripping at a predetermined section of its outer surface. That is, the anti-slip means may be formed in any one of the following forms: a splined outer surface, a knurled outer surface, a circular cross section, a polygonal cross section, or a pair or more of opposing gripping surfaces, thereby facilitating the threading operation of the internally threaded body 141.

[0117] When the pair of parallel-tapered integrated female thread portions 143 are formed to have different specifications, different diameter joints are possible. For example, when rebar construction is carried out from bottom to top, if rebars with different diameters need to be joined, this can be accommodated through a different diameter joint.

Claims

1. In a threaded connection structure between an internally threaded body and an externally threaded body for connecting reinforcing bars, The female-threaded body includes a parallel female-threaded portion formed with parallel threads on an inner diameter thereof, and a parallel-tapered integrated female-threaded portion formed integrally with a tapered female-threaded portion whose inner diameter narrows at one end of the parallel female-threaded portion; The male-threaded body includes a parallel male-threaded portion formed with parallel threads on an outer diameter thereof, and a parallel-tapered integrated male-threaded portion formed integrally with a tapered male-threaded portion whose outer diameter narrows at one end of the parallel male-threaded portion, The minor diameter of the parallel female thread portion is larger than the maximum minor diameter of the tapered female thread portion, The major diameter of the parallel male thread portion is larger than the maximum major diameter of the tapered male thread portion, a thread discontinuity is formed between the parallel female thread portion and the tapered female thread portion, and between the parallel male thread portion and the tapered male thread portion, The inner diameter of the parallel female thread portion is formed larger than the maximum outer diameter of the tapered male thread portion, The male threaded body or the female threaded body is integrated with a reinforcing bar, A male or female screw is integrated into one end of the reinforcing bar, The reinforcing bar has a male thread integrated into both ends, The reinforcing bar has an internally threaded body integrated at both ends thereof, A male threaded body and a female threaded body are integrated with both side ends of the reinforcing bar, When male threaded bodies are integrated with both ends of the reinforcing bar, the rotation directions of the threads of the male threaded bodies at both ends are formed in the same or opposite directions to each other; When female threaded bodies are integrated at both ends of the reinforcing bar, the rotation directions of the threads of the female threaded bodies at both ends may be the same or opposite to each other; When the male and female threaded bodies are respectively integrated at both ends of the reinforcing bar, the rotation directions of the threads of the female and male threaded bodies at both ends are formed in the same or opposite directions to each other, When rotated in the direction of thread rotation, the tapered female thread portion and the tapered male thread portion are formed to begin to engage before the parallel thread portion; or When rotated in the direction of the thread rotation, the tapered female thread portion and the tapered male thread portion and the parallel thread are formed to simultaneously begin to engage with each other. A parallel-tapered integral threaded joint structure for connecting reinforcing bars, characterized by:

2. In a threaded connection structure between an internally threaded body and an externally threaded body for connecting reinforcing bars, The female thread body is a reinforcing bar coupler in which two parallel-taper integrated female thread portions are formed integrally with a parallel female thread portion formed with parallel threads on the inner diameter and a tapered female thread portion whose inner diameter narrows at one end of the parallel female thread portion, and the two parallel-taper integrated female thread portions are formed on the same axis so that the tapered thread directions face each other, The male threaded body is a reinforcing bar having a parallel-tapered integrated male thread portion formed integrally with a parallel male thread portion formed with parallel threads on the outer diameter and a tapered male thread portion whose outer diameter narrows at one end of the parallel male thread portion, a thread discontinuity is formed between the parallel female thread portion and the tapered female thread portion, and between the parallel male thread portion and the tapered male thread portion, The inner diameter of the parallel female thread portion is formed larger than the maximum outer diameter of the tapered male thread portion, The male threaded body is integrated with a reinforcing bar, A male thread body is integrated with one side end of the reinforcing bar, Male threaded bodies are integrated with both end portions of the reinforcing bar, When male threaded bodies are integrated with both ends of the reinforcing bar, the rotation directions of the threads of the male threaded bodies at both ends are formed in the same or opposite directions to each other, When rotated in the direction of thread rotation, the tapered female thread portion and the tapered male thread portion are formed to begin to engage before the parallel thread portion; or When rotated in the direction of the thread rotation, the tapered female thread portion and the tapered male thread portion and the parallel thread are formed to simultaneously begin to engage with each other. A parallel-tapered integral threaded joint structure for connecting reinforcing bars, characterized by:

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