阅读说明：本技术 一种装配式结构钢筋直螺纹连接装置及其连接方法 (Assembly type structural steel bar straight thread connecting device and connecting method thereof ) 是由 储宏道 于 2020-05-18 设计创作，主要内容包括：一种装配式结构钢筋直螺纹连接装置,包括螺套和连接套筒。连接套筒设有第一内孔和第二内孔,螺套的内螺纹用于与第一钢筋丝头的外螺纹相旋合形成第一螺纹副,连接套筒的第一内孔的内螺纹用于与第二钢筋丝头的外螺纹相旋合形成第二螺旋副,连接套筒的第二内孔的内螺纹用于与螺套的外螺纹相旋合形成第三螺纹副；其中,第一螺纹副与第二螺纹副的螺距不相等,第一螺纹副与第三螺纹副的螺距不相等,第二螺纹副与第三螺纹副的螺距相等。本发明还公开了装配式结构钢筋直螺纹连接方法。本发明能在两根钢筋不能沿径向和轴向移动、不能转动、且两根钢筋丝头螺纹的螺旋线存在偏差错位的情况下,实现两根钢筋之间的可靠连接。(The utility model provides an assembled structural steel bar straight thread connecting device, includes swivel nut and connecting sleeve. The connecting sleeve is provided with a first inner hole and a second inner hole, the inner thread of the screw sleeve is used for being screwed with the outer thread of the first steel bar screw head to form a first screw pair, the inner thread of the first inner hole of the connecting sleeve is used for being screwed with the outer thread of the second steel bar screw head to form a second screw pair, and the inner thread of the second inner hole of the connecting sleeve is used for being screwed with the outer thread of the screw sleeve to form a third screw pair; the thread pitch of the first thread pair is not equal to that of the second thread pair, the thread pitch of the first thread pair is not equal to that of the third thread pair, and the thread pitch of the second thread pair is equal to that of the third thread pair. The invention also discloses a method for connecting the straight threads of the assembled structural steel bars. The invention can realize the reliable connection between two steel bars under the conditions that the two steel bars can not move along the radial direction and the axial direction and can not rotate and the spiral lines of the threads of the two steel bar thread heads have deviation and dislocation.)

1. An assembly type structural steel bar straight thread connecting device comprises a threaded sleeve and a connecting sleeve; the connecting sleeve is provided with a central through hole which is communicated along the axial direction, the central through hole comprises a first inner hole and a second inner hole which are sequentially connected, one end of the first inner hole is communicated with the end face of one end of the connecting sleeve, the other end of the first inner hole is connected with the second inner hole, and the other end of the second inner hole is communicated with the end face of the other end of the connecting sleeve; the first inner hole of the connecting sleeve, the second inner hole of the connecting sleeve and the hole wall of the inner hole of the threaded sleeve are respectively provided with an internal thread, and the outer side surface of the threaded sleeve is provided with an external thread; the internal thread of the screw sleeve is equal to the external thread pitch of the first steel bar screw head and is screwed to form a first thread pair, the internal thread of the first inner hole of the connecting sleeve is equal to the external thread pitch of the second steel bar screw head and is screwed to form a second thread pair, and the internal thread of the second inner hole of the connecting sleeve is equal to the external thread pitch of the screw sleeve and is screwed to form a third thread pair; the internal thread of the first inner hole of the connecting sleeve and the internal thread of the threaded sleeve are both straight threads; the thread pitch of the first thread pair is not equal to that of the second thread pair, the thread pitch of the first thread pair is not equal to that of the third thread pair, and the thread pitch of the second thread pair is equal to that of the third thread pair.

2. The fabricated structural steel straight thread connecting device according to claim 1, wherein the opening of the second inner bore of the connecting sleeve is a conical bore, and the diameter of the opening of the conical bore is larger than the diameter of the bottom of the conical bore; the diameter of the bottom of the conical hole is equal to the size of the major diameter of the internal thread of the second inner hole of the connecting sleeve, and the difference between the diameter of the hole opening and the diameter of the bottom of the hole is not less than twice of the maximum deviation value allowed by the axis of the first steel bar wire head and the axis of the second steel bar wire head in the technical regulations of the industry.

3. The fabricated structural reinforcing straight thread connecting device as claimed in claim 2, wherein a third inner hole having a diameter equal to the bottom diameter of the conical hole of the coupling sleeve is provided between the bottom of the conical hole of the coupling sleeve and the internal thread of the second inner hole.

4. The fabricated structural reinforcing straight thread connection of claim 1, wherein a pitch of the first thread pair is greater than a pitch of the second thread pair.

5. The fabricated structural reinforcing straight thread connecting device as claimed in claim 1 or 2, wherein the connecting sleeve has an outer shape of a hexagonal polygonal prism or a cylinder.

6. The fabricated structural reinforcing straight thread connecting device as claimed in claim 1, wherein an outer side surface of one end of the threaded sleeve is provided with a step protruding outward in a radial direction.

7. The fabricated structural reinforcing straight thread connecting device as claimed in claim 6, wherein the step has an outer shape of a hexagonal polygonal prism or a cylinder.

8. The assembly-type structural steel straight thread connecting device according to claim 1, wherein the assembly-type structural steel straight thread connecting device further comprises one or more lock nuts, the lock nuts are screwed on the first steel wire head and/or the second steel wire head, and an end surface of each lock nut abuts against an end surface of the corresponding screw sleeve or connecting sleeve.

9. A method for connecting straight threads of fabricated structural steel bars is characterized by comprising the following steps:

screwing the internal thread of the screw sleeve and the external thread of the first steel bar screw head to form a first thread pair;

screwing the internal thread of the first inner hole of the connecting sleeve with the external thread of the second steel bar screw head to form a second thread pair;

rotating the connecting sleeve in the direction that the connecting sleeve is close to the threaded sleeve, wherein the internal thread of the second inner hole of the connecting sleeve is screwed with the external thread of the threaded sleeve to form a third thread pair, when the internal thread of the second inner hole of the connecting sleeve and the external thread of the threaded sleeve cannot be screwed, namely, the two threads have helical line deviation and dislocation, the number of turns of the connecting sleeve and the threaded sleeve in the same direction reaches A/| P1-P2| turn, and the internal thread of the second inner hole of the connecting sleeve can be screwed with the external thread of the threaded sleeve to form the third thread pair; a is a spiral line deviation value existing between an inner thread of a second inner hole of the connecting sleeve and an outer thread of the threaded sleeve, P1 is a thread pitch of the first thread pair, P2 is a thread pitch of the second thread pair, P1 is not equal to P2, and I P1-P2I is an axial distance deviation generated after the connecting sleeve and the threaded sleeve rotate for one turn in the same direction, the spiral line deviation value A can be offset when the connecting sleeve and the threaded sleeve rotate in the same direction for a turn number of A/IP 1-P2I turns, and an inner thread of the second inner hole of the connecting sleeve can be screwed with the outer thread of the threaded sleeve to form a third thread pair.

10. The method of claim 9, wherein the first thread pair has a different pitch than the second thread pair, the first thread pair has a different pitch than the third thread pair, and the second thread pair has a different pitch than the third thread pair; the screw pitch difference between the first thread pair and the second thread pair is utilized to correct the helical line deviation and dislocation between the internal thread of the second inner hole of the connecting sleeve and the external thread of the screw sleeve, so that the screwing connection of the third thread pair is realized.

11. The method for connecting the straight threads of the fabricated structural steel bar according to claim 9, wherein the opening of the second inner hole of the connecting sleeve is a conical hole, and the diameter of the opening of the conical hole is larger than the diameter of the bottom of the conical hole; the diameter of the bottom of the conical hole is equal to the size of the major diameter of the internal thread of the second inner hole of the connecting sleeve, and the difference between the diameter of the hole opening and the diameter of the bottom of the hole is not less than two times of the maximum deviation value allowed by the axis of the first steel bar wire head and the axis of the second steel bar wire head in the technical regulations of the industry; and in the process that the connecting sleeve is screwed into the threaded sleeve, the radial deviation between the axis of the first steel bar wire head and the axis of the second steel bar wire head is corrected through the conical hole, so that the screwing connection of the third thread pair is realized.

Technical Field

The invention relates to a device and a method for connecting steel bars in the construction of an assembly type structure building, which are suitable for the connection of the steel bars between assembly type prefabricated components and between the prefabricated components and cast-in-place and post-cast concrete structures and can be used in the building environment that the steel bars cannot move along the radial direction and the axial direction and can not rotate and the helical line deviation of the thread of a steel bar thread is staggered.

Background

The industry standard "technical rules for prefabricated concrete structures" (JGJ 1-2014, hereinafter "rules") states: the key of success and failure of the assembly type structure lies in the connection technology between prefabricated components and between the prefabricated components and cast-in-place and post-cast concrete, wherein the connection technology comprises the selection of connection joints and the structural design of connection nodes, and the connection technology of the prefabricated components is the key and core technology of the assembly type structure. Among them, the steel bar sleeve grouting joint technology is the main joint technology recommended by the regulation, and is also an important foundation for forming various prefabricated concrete structures (the regulation specification is 3.0.3 and 4.2.1).

However, through a series of research and analysis and engineering practice on the specified connection joint for the steel bar sleeve grouting, the connection technology is not ideal, has a plurality of defects which are difficult to overcome, and has become a bottleneck for restricting the large-scale and high-quality development of the fabricated building, and the main defects are listed as follows:

1. high cost, complex operation and difficult detection. The "building hour newspaper" at 2016, 4, 11, 7 th edition has reported this: "not only do the consumptive materials many (require strict high strength grouting material and thick and long sleeve again), with high costs, grouting sleeve connects the operating procedure complicacy moreover, the specialty requires highly, and the link that influences the quality in the construction, factor are numerous, and difficult to avoid, difficult to control, more difficult to detect, is difficult to inspect how to the end of the quality of attach fitting? In this regard, technical experts have been concerned about uneasiness ";

2. the grouting construction is obviously affected by the environmental temperature, and the construction region and season are limited. Technical code for grouting connection of steel sleeve connection of reinforcement JGJ 355-20156.3.9 article 2: during grouting construction, the environmental temperature meets the requirements of the operating specification of grouting materials; the construction is not suitable when the environmental temperature is lower than 5 ℃, and the construction cannot be carried out when the environmental temperature is lower than 0 ℃; when the environmental temperature is higher than 30 ℃, measures for reducing the temperature of the grouting material mixture are adopted;

3. the grouting material needs to be used up within 30 minutes after water is added, and can only be discarded after overtime. The final specification of the 'technical specification for grouting and connecting reinforced sleeve' JGJ 355-2015 notes 6.3.9: the fluidity index of the grouting material mixture is gradually reduced along with the time, and in order to ensure grouting construction, the specified grouting material is preferably used up within 30min after water is added. The grouting material mixture can not be mixed with the grouting material and water again, and the grouting material after the specified time is exceeded and the residual grouting material can only be discarded.

The main technology for connecting reinforcing steel bars in the construction industry at present is mechanical connection of the reinforcing steel bars, namely a connection method for transmitting the force in one reinforcing steel bar to the other reinforcing steel bar through the mechanical meshing action of the reinforcing steel bars and connecting pieces or other intervening materials or the pressure bearing action of the end faces of the reinforcing steel bars. The main form of the mechanical connection of the steel bars is threaded connection, and the threaded connection is that special equipment is used for firstly manufacturing steel bar screw heads with corresponding threads at the end parts of the two steel bars, and then connecting the two steel bars by using a connecting sleeve with corresponding internal threads.

Because the reinforcing bars to be connected have deviation and dislocation in radial and axial positions when two prefabricated components of the fabricated building are assembled, the method is clearly defined in the regulation: "the deviation of the connecting steel bar from the central line of the sleeve or the hole is not more than 5 mm" (see "rule" 12.3.2), and because the steel bar embedded in the prefabricated member can not move along the radial direction and the axial direction and can not rotate, and the thread of the steel bar head is pre-processed and embedded in the member together with the steel bar, the implementation of the connection can encounter two problems: one of the problems is to correct the radial dislocation of the axes of the two reinforcing steel bars; the other problem is that the spiral lines of the threads of the two embedded steel bar thread heads have deviation and dislocation, and the situation that the threads cannot be screwed due to thread interference can occur when the two steel bars are directly connected by the connecting sleeve because the steel bars are fixed in the component and cannot rotate and axially move; furthermore, the tensile strength of the joint must meet the tensile strength requirement specified in 3.0.5 of the mechanical connection of reinforcing bars technical code (JGJ 107-2016). Because of these technical difficulties, the threaded connection technology currently used on the market has not been applied to prefabricated components.

Disclosure of Invention

The invention aims to provide an assembly type structural steel bar straight thread connecting device which can realize reliable connection between two steel bars under the condition that the axes of the two steel bars are radially staggered.

Another object of the present invention is to provide a straight thread connection device for fabricated structural steel bars, which can reliably connect two steel bars when the two steel bars cannot move in the radial and axial directions and cannot rotate, and the helical lines of the threads of the two steel bar heads are deviated and dislocated.

The invention aims to solve another technical problem of providing a method for connecting the straight threads of the fabricated structural steel bars.

According to one aspect of the invention, the assembled structural steel bar straight thread connecting device comprises a threaded sleeve and a connecting sleeve; the connecting sleeve is provided with a central through hole which is communicated along the axial direction, the central through hole comprises a first inner hole and a second inner hole which are sequentially connected, one end of the first inner hole is communicated with the end face of one end of the connecting sleeve, the other end of the first inner hole is connected with the second inner hole, and the other end of the second inner hole is communicated with the end face of the other end of the connecting sleeve; the inner hole wall of the first inner hole of the connecting sleeve, the second inner hole of the connecting sleeve and the inner hole wall of the threaded sleeve are respectively provided with an internal thread, and the outer side surface of the threaded sleeve is provided with an external thread; the internal thread of the screw sleeve is equal to the external thread pitch of the first steel bar screw head and is screwed to form a first thread pair, the internal thread of the first inner hole of the connecting sleeve is equal to the external thread pitch of the second steel bar screw head and is screwed to form a second thread pair, and the internal thread of the second inner hole of the connecting sleeve is equal to the external thread pitch of the screw sleeve and is screwed to form a third thread pair; the internal thread of the first inner hole of the connecting sleeve and the internal thread of the threaded sleeve are both straight threads; the thread pitch of the first thread pair is not equal to that of the second thread pair, the thread pitch of the first thread pair is not equal to that of the third thread pair, and the thread pitch of the second thread pair is equal to that of the third thread pair.

In the above assembly type structural steel bar straight thread connecting device, the opening of the second inner hole of the connecting sleeve is a conical hole, and the diameter of the hole opening of the conical hole is larger than the diameter of the hole bottom of the conical hole; the diameter of the bottom of the conical hole is equal to the size of the major diameter of the internal thread of the second inner hole of the connecting sleeve, and the difference between the diameter of the hole opening and the diameter of the bottom of the hole is not less than twice of the maximum deviation value allowed by the axis of the first steel bar screw head and the axis of the second steel bar screw head in the technical regulations of the industry.

According to another aspect of the present invention, there is also provided a fabricated structural reinforcing bar straight-thread connecting method, comprising the steps of:

screwing the internal thread of the screw sleeve and the external thread of the first steel bar screw head to form a first thread pair;

screwing the internal thread of the first inner hole of the connecting sleeve with the external thread of the second steel bar screw head to form a second thread pair;

rotating the connecting sleeve in the direction that the connecting sleeve is close to the screw sleeve, wherein the internal thread of the second inner hole of the connecting sleeve is screwed with the external thread of the screw sleeve to form a third thread pair, when the internal thread of the second inner hole of the connecting sleeve and the external thread of the screw sleeve cannot be screwed, namely, the two threads have helical line deviation and dislocation, the number of turns of the connecting sleeve and the screw sleeve which are rotated in the same direction reaches A/| P1-P2| turns, and the internal thread of the second inner hole of the connecting sleeve can be screwed with the external thread of the screw sleeve to form the third thread pair; a is a spiral line deviation value existing between an inner thread of a second inner hole of the connecting sleeve and an outer thread of the threaded sleeve, P1 is a thread pitch of the first thread pair, P2 is a thread pitch of the second thread pair, P1 is not equal to P2, P1-P2 is an axial distance deviation generated after the connecting sleeve and the threaded sleeve rotate for one turn in the same direction, the spiral line deviation value A can be offset when the connecting sleeve and the threaded sleeve rotate in the same direction for a turn number of A/| P1-P2| turns, and an inner thread of the second inner hole of the connecting sleeve can be screwed with the outer thread of the threaded sleeve to form a third thread pair.

In the method for connecting the straight threads of the fabricated structural steel bar, the thread pitches of the first thread pair and the second thread pair are not equal, the thread pitches of the first thread pair and the third thread pair are not equal, and the thread pitches of the second thread pair and the third thread pair are equal; the screw thread deviation dislocation between the internal thread of the second inner hole of the connecting sleeve and the external thread of the screw sleeve can be corrected by utilizing the screw pitch difference of the first screw thread pair and the second screw thread pair, so that the screwing connection of the third screw thread pair is realized.

In the method for connecting the straight threads of the fabricated structural steel bar, the opening of the second inner hole of the connecting sleeve is a conical hole, and the diameter of the hole opening of the conical hole is larger than the diameter of the hole bottom of the conical hole; the diameter of the bottom of the conical hole is equal to the size of the major diameter of the internal thread of the second inner hole of the connecting sleeve, and the difference between the diameter of the hole opening and the diameter of the bottom of the hole is not less than two times of the maximum deviation value allowed by the axis of the first steel bar screw head and the axis of the second steel bar screw head in the technical regulations of the industry; and in the process that the connecting sleeve is screwed into the threaded sleeve, the radial deviation between the axis of the first steel bar wire head and the axis of the second steel bar wire head is corrected through the conical hole, so that the screwing connection of the third thread pair is realized.

After the technical scheme is adopted, the invention has the following advantages:

1. the screw pitches of the first thread pair and the second thread pair of the assembly type structure steel bar straight thread connecting device are not equal, the screw pitches of the first thread pair and the third thread pair are not equal, and the screw pitches of the second thread pair and the third thread pair are equal; when the internal thread of the second inner hole of the connecting sleeve and the external thread of the screw sleeve have helical line deviation dislocation (namely the helical line of the first reinforcing steel bar thread and the helical line of the second reinforcing steel bar thread have deviation dislocation), the helical line deviation dislocation between the internal thread of the second inner hole of the connecting sleeve and the external thread of the screw sleeve can be offset after the connecting sleeve and the screw sleeve rotate in the same direction for a certain number of turns by utilizing the axial distance deviation generated after the connecting sleeve and the screw sleeve rotate in the same direction for a circle, so that the rotatable connection of the third thread pair is realized, and then two reinforcing steel bars are reliably connected together;

2. in the process that the connecting sleeve is screwed into the threaded sleeve, the conical hole at the opening of the second inner hole of the connecting sleeve can correct the radial deviation between the axis of the first steel bar screw head and the axis of the second steel bar screw head, so that the rotatable connection of the third thread pair is realized;

3. on the basis of realizing the function of connection, the invention can meet the requirement of 3.0.5I-level tensile strength in the technical specification of mechanical connection of steel bars (JGJ 107-2016).

Drawings

Fig. 1 is an axial sectional view showing a fabricated construction-reinforcing-bar straight-thread coupling device according to a first embodiment of the present invention.

Fig. 2 shows an axial section through a connecting sleeve according to a first embodiment of the invention.

Fig. 3 shows a schematic view of prefabricated parts to which the connecting device according to the first embodiment of the present invention is applied before they are ready for connection.

Fig. 4 is a schematic view illustrating that the prefabricated parts are corrected for radial deviation of two reinforcing bars using the coupling device according to the first embodiment of the present invention.

Fig. 5 is a schematic view showing assembled prefabricated parts after the connection is completed using the connecting device according to the first embodiment of the present invention.

Fig. 6 shows a cross-sectional view a-a of fig. 4, wherein the coupling sleeve has the shape of a hexagonal polygonal prism.

Fig. 7 is an axial sectional view showing a fabricated construction-reinforcing-bar straight-thread coupling device according to a second embodiment of the present invention.

Detailed Description

Representative applications of the methods and apparatus according to the present patent application will be described in this section, which examples are provided to facilitate an understanding of the described embodiments. It will thus be apparent to one skilled in the art that the embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to not unnecessarily obscure the embodiments. Other applications are also possible, so that the following examples should not be considered limiting.

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in accordance with the embodiments. Although these embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments, it is understood that these examples are not limiting; such that other embodiments may be used and modifications may be made without departing from the spirit and scope of the embodiments.

Fig. 1 shows an axial sectional view of a fabricated construction-bar straight-thread coupling device according to a first embodiment of the present invention, and fig. 2 shows an axial sectional view of a coupling sleeve according to a first embodiment of the present invention. Referring to fig. 1 and 2, the fabricated-type structural reinforcing bar straight thread connection device according to the first embodiment of the present invention includes a threaded sleeve 1 and a connection sleeve 2.

The connecting sleeve 2 is provided with a central through hole which is through along the axial direction, the central through hole comprises a first inner hole 21 and a second inner hole 22 which are sequentially connected, one end of the first inner hole 21 is through the end face of one end of the connecting sleeve 2, the other end of the first inner hole 21 is connected with the second inner hole 22, and the other end of the second inner hole 22 is through the end face of the other end of the connecting sleeve 2; the first inner hole 21 of the connecting sleeve 2, the second inner hole 22 of the connecting sleeve 2 and the inner hole wall of the threaded sleeve 1 are respectively provided with an internal thread, and the outer side surface of the threaded sleeve 1 is provided with an external thread; the internal thread of the screw sleeve 1 is equal to the external thread pitch of the first steel bar thread head 61 and is screwed to form a first thread pair M1, the internal thread of the first inner hole 21 of the connecting sleeve 2 is equal to the external thread pitch of the second steel bar thread head 62 and is screwed to form a second thread pair M2, and the internal thread of the second inner hole 22 of the connecting sleeve 2 is equal to the external thread pitch of the screw sleeve 1 and is screwed to form a third thread pair M3; the internal thread of the first inner hole 21 of the connecting sleeve 2 and the internal thread of the screw sleeve 1 are both straight threads. The thread pitches of the first thread pair M1 and the second thread pair M2 are not equal (that is, the thread pitch of the internal thread of the thread sleeve 1, the thread pitch of the external thread of the first reinforcing steel bar head 61, the thread pitch of the internal thread of the first inner hole 21 of the connecting sleeve 2, and the thread pitch of the external thread of the second reinforcing steel bar head 62 are not equal), the thread pitches of the first thread pair M1 and the third thread pair M3 are not equal (that is, the thread pitch of the internal thread of the thread sleeve 1, the thread pitch of the external thread of the first reinforcing steel bar head 61, the thread pitch of the internal thread of the second inner hole 22 of the connecting sleeve 2, and the thread pitch of the external thread of the thread sleeve 1 are not equal), and the thread pitches of the second thread pair M2 and the third thread pair M3 are equal (that is, the thread pitch of the internal thread of the first inner hole 21 of the connecting sleeve 2, the thread pitch of the external thread of the second reinforcing steel bar head 62, and the internal thread pitch of the internal thread of the second inner hole 22 of the connecting sleeve 2, and the external thread pitch of the thread of the sleeve 1 are equal).

In the embodiment, the opening of the second inner hole 22 of the connecting sleeve 2 is a conical hole 24, and the diameter D of the opening of the conical hole 24 is greater than the diameter D of the bottom of the conical hole; the hole bottom diameter D of the conical hole 24 is equal to the major diameter of the internal thread of the second inner hole 22 of the connecting sleeve 2, and the difference between the hole opening diameter D and the hole bottom diameter D is not less than twice of the maximum deviation value allowed by the axis of the first reinforcing steel wire head 61 and the axis of the second reinforcing steel wire head 62 in the technical regulations in the industry. For example, when the selected technical specification is "technical specification for prefabricated concrete structures" (JGJ 1-2014), article 12.3.2 specifies: "the connecting reinforcement is not deviated from the center line of the sleeve or the hole by more than 5 mm", and if the specification of 12.3.2 in accordance with the technical code of prefabricated concrete structures is followed, the difference between the diameter D of the hole opening and the diameter D of the hole bottom should be 10mm or more. If other technical rules are selected, the values specified by the other technical rules are used as the standard.

In the present embodiment, a third inner bore 23 is provided between the bottom of the conical bore 24 of the connecting sleeve 2 and the internal thread of the second inner bore 22, and the diameter of the third inner bore 23 is equal to the bottom diameter d of the conical bore 24 of the connecting sleeve 2. The third inner hole 23 is used for hooping the large diameter of the external thread of the screw sleeve 1 to enable the axis of the first steel wire head 61 and the axis of the second steel wire head 62 to be always on the same axis in the process of rotating the connecting sleeve 2 and the screw sleeve 1 in the same direction after the radial deviation between the axis of the first steel wire head 61 and the axis of the second steel wire head 62 is corrected by the conical hole 24 of the connecting sleeve 2.

Optionally, the pitch of the first thread pair M1 is greater than the pitch of the second thread pair M2.

The coupling sleeve 2 may have the shape of a hexagonal polygonal prism or cylinder, or other shape compatible with a rotary tool. In the present embodiment, the connecting sleeve 2 has a hexagonal polygonal prism shape.

In this embodiment, the outer side surface of one end of the screw sleeve 1 is provided with a step 11 protruding outward in the radial direction, the minimum dimension of the step 11 is larger than the major diameter dimension of the external thread of the screw sleeve 1, and the step 11 is used for stopping the connecting sleeve 2. The outer shape of the step 11 may be a hexagonal polygonal cylinder, a cylinder or other shape compatible with a rotary tool.

Hereinafter, a process of connecting reinforcing bars of two prefabricated units together using the connecting device according to the first embodiment of the present invention will be described with reference to fig. 3 to 6. The specific implementation steps are as follows:

a. firstly, a straight thread first reinforcing steel bar thread 61 and a straight thread second reinforcing steel bar thread 62 are respectively processed at the ends of the first reinforcing steel bar 6a and the second reinforcing steel bar 6b by special equipment, the thread turning directions of the two reinforcing steel bars are the same, and the second reinforcing steel bar thread 62 is the length of a lengthened thread.

b. As shown in fig. 3, when the concrete is precast or at a construction site, the steel bars with the processed thread ends are pre-embedded, the first steel bar 6a is pre-embedded in the first prefabricated part 5a, and the second steel bar 6b is pre-embedded in the second prefabricated part 5 b. Screwing the internal thread of the first thread sleeve 1 with the external thread of the first steel bar thread head 61 to form a first thread pair M1; and screwing the internal thread of the first inner hole 21 of the connecting sleeve 2 with the external thread of the second reinforcing steel wire head 62 to form a second thread pair M2. At the construction site, second prefabricated element 5b is seated on first prefabricated element 5a, and intermediate layer 5c is "set mortar" of cement paste.

c. In the example of fig. 3, the radial offset T of the axis of the first reinforcing wire head 61 from the axis of the second reinforcing wire head 62 is 5mm (required by "rule" 12.3.2: when the connecting reinforcing wire is inclined, the connecting reinforcing wire should be aligned, the deviation of the connecting reinforcing wire from the center line of the sleeve or the hole should not exceed 5mm), because the opening diameter D of the conical hole 24 of the connecting sleeve 2 is larger than the major diameter dimension of the external thread of the thread insert 1 plus 10mm, the external thread of the first thread insert 1 which is screwed on the first reinforcing wire head 61 in advance always falls within the range of the conical hole 24 of the connecting sleeve 2 along the axial direction of the second reinforcing wire head 62 under the connecting sleeve 2.

d. In the example of fig. 4, the rotating tool 4 is rotated to screw the connecting sleeve 2 in the direction of the first steel wire head 61, when the conical surface of the conical hole 24 of the connecting sleeve 2 contacts the external thread of the screw sleeve 1, the screwing is continued, the screwing torque is conducted through the internal thread of the first inner hole 21 of the connecting sleeve 2 and is boosted with the conical surface of the conical hole 24, the torque is enough to push the axis of the first steel wire head 61 and the axis of the second steel wire head 62 to be close to each other along the conical surface taper of the conical hole 24 of the connecting sleeve 2, the radial offset is corrected, and the radial offset value T is reduced from 5mm in the example of fig. 3 to 1.5mm in the example of fig. 4.

e. In the example of fig. 5, the rotation tool 4 is continuously rotated to rotate the coupling sleeve 2 in a direction to bring the coupling sleeve 2 closer to the nut 1, and the radial misalignment of the axis of the first wire head 61 and the axis of the second wire head 62 is corrected to T ═ 0.

Continuously rotating the connecting sleeve 2 along the direction of enabling the connecting sleeve 2 to be close to the screw sleeve 1, wherein the internal thread of the second inner hole 22 of the connecting sleeve 2 can be directly screwed with the external thread of the screw sleeve 1 to form a third thread pair M3, screwing the connecting sleeve 2 until the connecting sleeve abuts against the step 11 of the screw sleeve 1, and screwing the connecting sleeve hard to complete connection.

When the internal thread of the second inner hole 22 of the connecting sleeve 2 and the external thread of the screw sleeve 1 cannot be screwed, namely, two threads have helical line deviation and dislocation, the first external teeth of the internal thread of the second inner hole 22 of the connecting sleeve 2 can be propped against the first external teeth of the external thread of the screw sleeve 1, torque is transmitted through the friction effect of the contact surfaces of the two external teeth, and the connecting sleeve 2 is rotated to drive the screw sleeve 1 to rotate in the same direction. The pitch P1 of the first thread pair M1 is not equal to the pitch P2 of the second thread pair M2, and different implementation steps are taken in the following two cases that P2 < P1 and P2 > P1:

1) the pitch P2 of the second thread pair M2 < the pitch P1 of the first thread pair M1. The first thread pair M1 rotates for one circle, namely, the screwing distance of the thread insert 1 along the axis of the first steel wire head 61 to the tail direction of the first steel wire head 61 is P1, the second thread pair M2 rotates for one circle, namely, the screwing distance of the connecting sleeve 2 along the axis of the second steel wire head 62 to the tail direction of the first steel wire head 61 is P2, P2 is less than P1, namely, the screwing distance of the connecting sleeve 2 rotates for one circle is less than the screwing distance of the thread insert 1 (the screwing speed of the connecting sleeve 2 is slower than that of the thread insert 1), in the process that the rotating connecting sleeve 2 drives the thread insert 1 to rotate, the first outer side tooth of the internal thread of the second inner hole 22 of the connecting sleeve 2 can be separated from the contact with the first outer side tooth of the external thread of the thread insert 1, the thread insert 1 stops screwing, at the moment, the helix of the continuously rotating connecting sleeve 2 can shorten the deviation between the internal thread of the second inner hole 22 of the connecting sleeve 2 and the external thread of the thread insert 1, the connecting sleeve 2 can contact with the threaded sleeve 1 again and drive the threaded sleeve 1 to screw in, and the steps are repeated; a is the helical line deviation value existing between the internal thread of the second inner hole 22 of the connecting sleeve 2 and the external thread of the thread insert 1, after the number of turns of the connecting sleeve 2 and the thread insert 1 in the direction of the tail part of the first steel bar thread head 61 reaches A/| P1-P2| turns, the helical line deviation value A can be offset, and the internal thread of the second inner hole 22 of the connecting sleeve 2 can be screwed with the external thread of the thread insert 1 to form a third thread pair M3. Screwing in the connecting sleeve 2 until the connecting sleeve abuts against the step 11 of the threaded sleeve 1, and screwing down with force to complete connection. When the pitch P2 of the second thread pair M2 is less than the pitch P1 of the first thread pair M1, the connecting device of the first embodiment of the invention can generate tensile force on two connected steel bars, and can be used for pre-tensioning or post-tensioning prestressed members of prestressed prefabricated buildings.

2) The pitch P2 of the second thread pair M2 > the pitch P1 of the first thread pair M1. The first thread pair M1 rotates one circle, namely the screwing distance of the thread insert 1 along the axis of the first steel wire head 61 to the tail direction of the first steel wire head 61 is P1, the second thread pair M2 rotates one circle, namely the screwing distance of the connecting sleeve 2 along the axis of the second steel wire head 62 to the tail direction of the first steel wire head 61 is P2, P2 is more than P2, namely the screwing distance of the connecting sleeve 2 rotates one circle is more than the screwing distance of the thread insert 1 (the screwing speed of the connecting sleeve 2 is faster than that of the thread insert 1), in the process that the rotary connecting sleeve 2 drives the thread insert 1 to rotate, the first outer tooth of the internal thread of the second inner hole 22 of the connecting sleeve 2 can prop against the first outer tooth of the external thread of the thread insert 1, so that the connecting sleeve 2 cannot be screwed, at this time, another rotary tool is used for rotating the step 11 of the thread insert 1, so that the thread insert 1 is screwed to the tail end direction of the first steel wire head 11, and then the connecting sleeve 2 is rotated, the connecting sleeve 2 is contacted with the threaded sleeve 1 again and drives the threaded sleeve 1 to screw in, so that the helical line deviation between the internal thread of the second inner hole 22 of the connecting sleeve 2 and the external thread of the threaded sleeve 1 is shortened, and the steps are repeated; a is the helical line deviation value existing between the internal thread of the second inner hole 22 of the connecting sleeve 2 and the external thread of the thread insert 1, after the number of turns of the connecting sleeve 2 and the thread insert 1 in the direction of the tail part of the first steel bar thread head 61 reaches A/| P1-P2| turns, the helical line deviation value A can be offset, and the internal thread of the second inner hole 22 of the connecting sleeve 2 can be screwed with the external thread of the thread insert 1 to form a third thread pair M3. Screwing in the connecting sleeve 2 until the connecting sleeve abuts against the step 11 of the threaded sleeve 1, and screwing down with force to complete connection.

Taking the steel bar with the specification of phi 25 as an example, under the condition that the connection length is 10 times of the diameter of the steel bar, the offset angle alpha of the central line of the connecting device to the initial position of the axis of the steel bar after the connection is finished is about 1 degree.

Fig. 7 is an axial sectional view showing a fabricated construction-reinforcing-bar straight-thread coupling device according to a second embodiment of the present invention. The second embodiment is mainly different from the first embodiment in that the fabricated structural steel bar straight thread connecting device according to the second embodiment of the invention comprises two locking nuts 3a and 3b, the locking nut 3a is spirally sleeved on a first steel bar thread 61, the locking nut 3b is spirally sleeved on a second steel bar thread 62, the end surface of the locking nut 3a abuts against the end surface of the thread sleeve 1, and the end surface of the locking nut 3b abuts against the end surface of the connecting sleeve 2; the lock nut 3a or 3b can be used to position the screw sleeve 1 or the connecting sleeve 2 at a proper position within the length range of the screw head so that the screw sleeve cannot move towards the tail of the reinforcing steel bar screw head.

In other embodiments, the lock nut 3a may be screwed only between the tail end of the first steel wire rod 61 and the end surface of the screw sleeve 1, or the lock nut 3b may be screwed only between the tail end of the second steel wire rod 62 and the end surface of the connecting sleeve 2, and after the connection is completed, the end surface of the lock nut 3a or 3b abuts against the end surface of the corresponding screw sleeve 1 or connecting sleeve 2.

The connecting device and the connecting method provided by the embodiment of the invention are particularly suitable for connecting the prefabricated components and the steel bars between the prefabricated components and the cast-in-place and post-cast concrete structures, are simple and convenient to operate, are not limited by external temperature, have no maintenance period after connection, and have the advantages of easiness in detection, zero energy consumption, no auxiliary material and low cost.