Reinforcement bar joint unit

Abstract

Bleeding of air from inside of a pipe connected to a grout discharge opening of a grout-filling type rebar coupler is facilitated, and dislodging of a stop valve fit to the pipe, from the pipe, is made difficult.　A stop valve (1, 101, 201) is fit to a pipe 16 connected to a grout discharge opening 15 of a grout-filling type rebar coupler 10. The stop valve 1 has a main unit 20 having a conical trapezoidal shape, and a male thread (22, 122, 222) provided on an outer circumferential face of the main unit 20. Air within the pipe 16 is bled via a root 22b of the male thread 22 of the stop valve 1. Accordingly, air is not readily retained within the pipe 18. Also, a crest 22a of the male thread 22 digs into the inner side of the pipe 16. Accordingly, the stop valve 1 is not readily dislodged from the pipe 16 when the filling pressure of the grouting material is raised.

Description

Technical Field

[0001] This Disclosure relates to a stopper for a grout-filled reinforcing bar joint and a reinforcing bar joint unit provided with the same.

Background Art

[0002] for sealing the opening of a communication pipe (pipe) communicating with the mortar discharge port of a mortar-filled reinforcing bar joint, a stopper fitted to the opening is used. As such a stopper, one provided with a plug body, a through hole penetrating the plug body, and a piston body movable within the through hole under the action of mortar pressure is known (for example, Patent Document 1). When the pressure-receiving body formed on the piston body receives the mortar pressure, the piston body within the through hole moves, and the through hole is blocked by the pressure-receiving body being pressed against the plug body.

[0003] When mortar is filled into the mortar-filled reinforcing bar joint, the mortar enters the through hole of the plug body and solidifies. After completion of the filling of the mortar, it is difficult to remove the solidified mortar within the through hole by removing the stopper from the pipe. Therefore, it is difficult to reuse the stopper. To solve this problem, a stopper provided with a notch portion communicating the inside and the outside of the discharge hole (opening) on the outer peripheral surface has been proposed (Patent Document 2). In the stopper described in Patent Document 2, since the notch portion is provided on the outer peripheral surface of the stopper, the hardened grout material can be easily removed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The stopper described in Patent Document 2 is fitted into the opening of a pipe with the notch facing upwards. This ensures that when grout is filled, no air remains inside the pipe and is expelled to the outside through the notch. However, in sites where many fittings are used, the process of fitting the stopper while checking the position of the notch is extremely cumbersome. If the stopper is fitted with the notch in the wrong position, air will remain inside the pipe.

[0006] Furthermore, to ensure that the grout material is securely filled, the filling pressure of the grout material may be increased after filling. However, increasing the filling pressure makes the stopper more likely to come off the pipe. In this case, one might consider pushing the stopper in firmly to prevent it from coming off. However, if the force used to push the stopper in is too strong, local deformation of the stopper may occur, eliminating the gap that should be defined between the pipe and the stopper by the notch, which may make it difficult for air to be expelled.

[0007] In view of the above background, the present invention aims to facilitate the discharge of air from the pipe connected to the grout outlet of a grout-filled reinforced bar joint, and to make it difficult for the stopper fitted to the pipe to come off. [Means for solving the problem]

[0008] To solve the above problems, one aspect of the present invention provides a stopper (1, 101, 201) for a grout-filled reinforcement joint, comprising a frustoconical body (20) and male threads (22, 122, 222) provided on the outer circumferential surface of the body.

[0009] In this configuration, air inside the pipe is discharged through the grooves of the male threads of the stopper. Therefore, air is less likely to remain inside the pipe. Also, the threads of the male threads bite into the inside of the pipe. Therefore, when the filling pressure of the grout material is increased, the stopper is less likely to come off the pipe.

[0010] Furthermore, in the above embodiment, the stopper may be formed from resin.

[0011] According to this embodiment, when the stopper is removed from the pipe after the grout material has hardened, the grout material adhering to the stopper can be easily removed from the stopper. Therefore, the stopper can be easily reused.

[0012] Furthermore, in the above embodiment, the stopper may further have an engaging portion (21) provided at the rear end (20a) of the main body.

[0013] According to this embodiment, when inserting or removing the stopper, the stopper can be rotated using a tool such as a wrench engaged with the engaging portion. Therefore, inserting and removing the stopper is easy.

[0014] Furthermore, in the embodiment having the above-described engaging portion, the engaging portion may be a projection that protrudes from the rear end of the main body and has a non-circular outer surface.

[0015] According to this embodiment, when inserting or removing the stopper, the worker can grip the engaging portion in a manner that facilitates torque transmission and rotate the stopper. Therefore, it is possible to insert or remove the stopper without using tools.

[0016] Furthermore, in the above embodiment, it is preferable that the male threads (22, 122) are tapered threads.

[0017] In this embodiment, the height of the threads is constant from the front end to the rear end of the male thread, and the threads are pointed at all positions in the axial direction. Therefore, even if there are variations in the dimensions of the stopper and pipe due to tolerances, deformation, or deposits, the pointed threads can bite into the inner surface of the pipe, ensuring that the stopper is securely fitted to the pipe.

[0018] Furthermore, in the above embodiment, it is preferable that the male screw (222) is a parallel screw.

[0019] According to this embodiment, threading of the male screw is easy. Therefore, the manufacturing cost of the stopper can be reduced.

[0020] Also, in the above aspect, the male screw (122) may be a double-threaded screw.

[0021] According to this aspect, compared with the case where the male screw is a single-threaded screw, the plug can be fitted into the pipe with fewer rotations. Therefore, the time required for fitting the plug can be shortened. Further, in a state where the plug is fitted into the pipe, since the screw grooves communicate with the inside of the pipe at two positions in the circumferential direction, it is possible to more reliably prevent air from remaining in the pipe during grout injection.

[0022] In order to solve the above problems, another aspect of the present invention is a reinforcing bar joint unit (18), including a grout-filled reinforcing bar joint (10) having a grout discharge port (15), a pipe (16) connected to the grout discharge port, and a plug (1, 101, 201) fitted into the pipe. The plug has a main body portion (20) having a frustum-conical shape and a male screw (22, 122, 222) provided on the outer peripheral surface of the main body portion.

[0023] According to this aspect, air in the pipe is discharged through the valleys of the male screw of the plug. Therefore, it is difficult for air to remain in the pipe. Further, the ridges of the male screw bite into the inside of the pipe. Therefore, when the filling pressure of the grout material is increased, the plug is difficult to come off from the pipe.

[0024] Also, in the reinforcing bar joint unit of the above aspect, the hardness of the material of the plug may be the same as or harder than the material of the pipe. ​​​​​​​​

[0027] According to this embodiment, it is easy to insert the stopper into the pipe. [Effects of the Invention]

[0028] With the above configuration, it is possible to easily discharge air from the pipe connected to the grout outlet of the grout-filled reinforcement joint, and to prevent the stopper fitted to the pipe from coming off. [Brief explanation of the drawing]

[0029] [Figure 1] Cross-sectional view of a column member to which the stopper of the present invention is applied. [Figure 2] Perspective view of the stopper according to the first embodiment [Figure 3] Cross-sectional view showing the stopper according to the first embodiment fitted onto the pipe. [Figure 4] Side view of the stopper according to the second embodiment [Figure 5] Side view of the stopper according to the third embodiment [Modes for carrying out the invention]

[0030] Embodiments of the present invention will be described in detail below with reference to the drawings.

[0031] <First Embodiment> Figure 1 is a cross-sectional view of a column member 2 to which the stopper 1 of the present invention is applied, showing the state before the start of grout filling. As shown in Figure 1, the column member 2 includes a lower column member 3 and an upper column member 4 made of precast concrete. The lower column member 3 and the upper column member 4 are arranged with a predetermined joint 5 between them. Formwork 6 is assembled around the outer circumference of the column member 2 to close the joint 5.

[0032] Multiple lower column main reinforcement bars 7, extending vertically, are embedded in the upper end of the lower column member 3, with their upper ends protruding. Multiple upper column main reinforcement bars 8, extending vertically, are embedded in the upper column member 4. Although the lower column main reinforcement bars 7 and upper column main reinforcement bars 8 are shown as round steel bars, they are actually deformed steel bars. Sleeve joints 10, embedded in the lower surface 9 of the upper column member 4 with their lower ends exposed, are attached to the lower ends of the upper column main reinforcement bars 8.

[0033] The sleeve joint 10 is a mechanical reinforcement joint that has a cylindrical shape extending in the vertical direction and mechanically connects the upper column main reinforcement 8 and the lower column main reinforcement 7. The lower end of the sleeve joint 10 forms an opening 11 on the lower surface 9 of the upper column member 4, and the upper end of the corresponding lower column main reinforcement 7 is inserted into this opening 11 at the lower end of the sleeve joint 10. The upper end of the sleeve joint 10 is provided with an opening 12 that is sized to allow the lower end of the upper column main reinforcement 8 to pass through. The lower end of the upper column main reinforcement 8 inserted through this opening 12 is located in the middle of the sleeve joint 10 in the vertical direction, and when the upper column member 4 is placed in a predetermined position on the lower column member 3, it faces the upper end of the lower column main reinforcement 7 with a small gap 13 between them. A cylindrical portion 14 that protrudes radially outward is provided on the outer circumferential surface near the upper end of the sleeve joint 10. The cylindrical portion 14 defines a grout discharge port 15.

[0034] A pipe 16 connected to the grout outlet 15 of the sleeve joint 10 is further embedded in the upper column member 4. The pipe 16 is made of a resin such as polyvinyl chloride. One end 16a of the pipe 16 is inserted into the inside of the cylindrical portion 14 and fixed to the cylindrical portion 14. The other end 16b of the pipe 16 is exposed on the side surface 17 of the upper column member 4. This pipe 16 becomes an air discharge passage for the sleeve joint 10 when grout material is filled into the sleeve joint 10. Typically, when the discharge of grout material from the pipe 16 is confirmed, the grout filling of the sleeve joint 10 is considered to be complete. In this embodiment, before the start of the grout filling work, stoppers 1 are fitted to the other end 16b of all pipes 16 from the outside of the upper column member 4. The air venting structure and fitting structure of the stoppers 1 will be described in detail later.

[0035] When joining the lower column member 3 and the upper column member 4, grout material is injected into the joint 5 between the lower column member 3 and the upper column member 4 from a grout injection port (not shown) provided in the formwork 6. The injected grout material passes through the joint 5 and fills the sleeve joint 10 through the opening 11 at the lower end of each sleeve joint 10. As the grout material rises inside the sleeve joint 10, the air inside the sleeve joint 10 is discharged to the outside through the grout outlet 15 and the pipe 16. The grout material is discharged from the grout outlet 15 while pushing out the air and fills the pipe 16 from one end 16a to the other end 16b. In this way, the grout material filled in the joint 5, the sleeve joint 10 and the pipe 16 hardens, joining the lower column member 3 and the upper column member 4. In other words, the sleeve joint 10 is a grout-filled reinforcement bar joint. Furthermore, these sleeve joints 10, pipes 16, and stoppers 1 constitute a sleeve joint unit 18, or rebar joint unit.

[0036] As shown in Figure 2, the stopper 1 has a frustoconical body portion 20 and an engaging portion 21 provided at the rear of the body portion 20 for engaging a tool. A male screw 22 is provided on the outer circumferential surface of the body portion 20. The stopper 1 is preferably made of resin, and the hardness of the material of the stopper 1 is the same as or harder than the material of the pipe 16 shown in Figure 1. Specifically, the Rockwell hardness of the material of the stopper 1, when measured on the M scale (HRM) or R scale (HRR), is the same as or harder than the material of the pipe 16 shown in Figure 1 (e.g., polyvinyl chloride). The material of the stopper 1 may be, for example, polypropylene or methacrylic resin.

[0037] In this embodiment, the male screw 22 is a single-start tapered male screw that tapers in diameter towards the insertion direction (forward) of the stopper 1. The male screw 22 is also a triangular screw. The male screw 22 and the main body 20 as a whole have a frustoconical shape.

[0038] The engaging portion 21 has an arbitrary shape that can engage with a tool (e.g., a wrench) for rotating the stopper 1. In the present embodiment, the engaging portion 21 is a protrusion formed in a substantially rectangular parallelepiped shape and protruding from the rear end 20a of the main body portion 20. That is, the outer surface of the rear end portion of the stopper 1 has a non-circular shape that facilitates torque transmission. In other embodiments, the engaging portion 21 may be formed to recess in the rear end 20a of the main body portion 20.

[0039] FIG. 3 is a cross-sectional view showing a state where the stopper 1 according to the present embodiment is fitted to the pipe 16. As shown in FIG. 3, the pitch diameter D1 of the male thread 22 at the front end 20b of the main body portion 20 of the stopper 1 is smaller than the inner diameter D2 of the pipe 16 (D1 < D2). Also, the pitch diameter D3 of the male thread 22 at the rear end 20a of the main body portion 20 of the stopper 1 is larger than the inner diameter D2 of the pipe 16 (D3 > D2).

[0040] Hereinafter, referring to FIGS. 1 to 3, the grout filling operation using this stopper 1 will be described. The stopper 1 is fitted to the other end 16b of the pipe 16 for all the sleeve joints 10 prior to the filling of the grout material. When fitting the stopper 1 to the pipe 16, the operator inserts the stopper 1 into the pipe 16 with the main body portion 20 facing forward (toward the upper column member 4). Since the pitch diameter D1 of the male thread 22 at the front end 20b of the main body portion 20 of the stopper 1 is smaller than the inner diameter D2 of the pipe 16 as described above, the operator can easily insert the main body portion 20 of the stopper 1 into the pipe 16.

[0041] Next, the worker grips the engaging portion 21 or engages a tool with the engaging portion 21 of the stopper 1 and rotates the stopper 1 clockwise. As a result, the male thread 22 formed on the outer circumference of the main body portion 20 bites into the inner surface of the pipe 16, and the stopper 1 enters the pipe 16 and is fitted into the pipe 16. At this time, the worker should rotate the stopper 1 until the torque required to rotate the stopper 1 reaches a predetermined value, or until the stopper 1 reaches a predetermined rotation angle from the position where it stops after being pushed into the pipe 16. In this way, because the stopper 1 has an engaging portion 21 provided at the rear end 20a of the main body portion 20, when fitting the stopper 1, the stopper 1 can be rotated using a tool such as a wrench engaged with the engaging portion 21, or by gripping the engaging portion 21 in a manner that facilitates torque transmission.

[0042] With stoppers 1 attached to the pipes 16 of all sleeve fittings 10, the worker injects grout material through a grout inlet (not shown). The injected grout material fills the inside of the sleeve fittings 10 and the pipes 16. The grout material fills the pipes 16 while pushing out air. The pushed-out air is discharged to the outside of the pipe 16 through the spiral space 23 between the inside of the pipe 16 and the valley 22b of the male thread 22 of the stopper 1. As a result, the grout material is filled into the pipes 16 without any air remaining inside.

[0043] To ensure that the grout material is completely filled, the worker increases the grout pressure. In the stopper 1 according to this embodiment, when the stopper 1 is fitted onto the other end 16b of the pipe 16, the threads 22a of the male thread 22 of the main body 20 bite into the inside of the pipe 16. Therefore, when the grout pressure is increased, the stopper 1 is less likely to come off the pipe 16. Furthermore, the hardness of the material of the stopper 1 is the same as or harder than the material of the pipe 16. Therefore, the threads (peaks 22a) of the male thread 22 of the stopper 1 bite into the inside of the pipe 16, making it more difficult for the stopper 1 to come off the pipe 16. Furthermore, in the stopper 1 according to this embodiment, the male thread 22 is a tapered thread. Therefore, the height of the threads is constant from the front end 20b to the rear end 20a of the male thread 22. That is, the threads are sharp at any position in the axial direction. Therefore, even if there are variations in the dimensions of the stopper 1 and pipe 16 due to tolerances, deformation, or deposits, the pointed threads can be bitten into the inner surface of pipe 16, ensuring that the stopper 1 is securely fitted onto pipe 16.

[0044] Furthermore, in the stopper 1 according to this embodiment, an engaging portion 21 is provided at the rear end 20a of the main body portion 20 of the stopper 1. As a result, when inserting or removing the stopper 1, even if it is not possible to grip the engaging portion 21 by hand and rotate the stopper 1, the stopper 1 can be easily rotated by using a tool such as a wrench on the engaging portion 21. Therefore, inserting and removing the stopper 1 is easy. In addition, since the engaging portion 21 is a projection with a non-circular outer surface that protrudes from the rear end 20a of the main body portion 20, when inserting or removing the stopper 1, the worker can grip the engaging portion 21 in a manner that facilitates torque transmission and rotate the stopper 1. Therefore, it is also possible to insert and remove the stopper 1 without using a tool.

[0045] After the grout has hardened, the worker removes the stopper 1 from the pipe 16 and pushes a finishing material such as mortar into the recess in the pipe 16 where the stopper 1 was removed to flatten the outer surface of the upper column member 4. The stopper 1 according to this embodiment is made of resin. Therefore, even if the hardened grout adheres to the male thread 22 of the stopper 1, the grout can be easily removed from the stopper 1. Thus, the stopper 1 can be easily reused. Note that the removal and finishing work of the stopper 1 is not mandatory. For example, the stopper 1 may be left in place. Alternatively, the stopper 1 may be cut along the outer surface of the upper column member 4, and only the portion protruding from the outer surface may be removed.

[0046] <Second Embodiment> Figure 4 is a side view of the stopper 101 according to the second embodiment. The stopper 101 according to the second embodiment differs from the stopper 1 according to the first embodiment shown in Figures 1 to 3 in that the male thread 122 is a double-threaded thread. Other parts are the same as in the first embodiment. In the following, the shape of the male thread 122 will be described in detail, and other parts will be denoted by the same reference numerals as in the first embodiment and their descriptions will be omitted. The same applies to subsequent embodiments.

[0047] As shown in Figure 4, the male thread 122 of the stopper 101 according to the second embodiment is a double-start tapered thread. With this configuration, the stopper 101 can be fitted onto the pipe 16 with fewer rotations compared to when the male thread 122 is a single-start thread. Therefore, the time required to fit the stopper 101 can be shortened. In addition, when the stopper 101 is fitted onto the pipe 16, the thread grooves (valleys 22b) communicate with the inside of the pipe 16 at two locations in the circumferential direction, so that air does not remain inside the pipe 16 when grout is injected can be prevented more reliably.

[0048] <Third Embodiment> Figure 5 is a side view of the stopper 201 according to the third embodiment. The stopper 201 according to the third embodiment differs from the stopper 1 according to the first embodiment shown in Figures 1 to 3 in that the male screw 222 is a parallel screw. Other parts are the same as in the first embodiment.

[0049] As shown in Figure 5, the male thread 222 of the stopper 201 according to the third embodiment is a single-thread parallel thread. The main body 20 is formed to have a frustoconical shape by grinding the parallel thread so that its diameter decreases in the direction of insertion of the stopper 201.

[0050] This configuration makes threading the male screw 222 easier compared to when the male screw 222 is a single-start tapered thread. Therefore, the manufacturing cost of the stopper 201 can be reduced.

[0051] This concludes the description of specific embodiments, but the present invention is not limited to the above embodiments and can be broadly modified and implemented. For example, in the above embodiment, the sleeve joint 10 connected two lower column main reinforcements 7 and upper column main reinforcements 8 that extended vertically, but the sleeve joint 10 may connect two beam main reinforcements that extended horizontally. Also, in the above embodiment, the joint was a sleeve joint 10 for connecting reinforcement bars, but it may also be a grout-filled reinforcement joint for connecting other reinforcement bars such as reinforcement bars made of aramid or reinforcement bars made of carbon. That is, the sleeve joint unit 18 in the above embodiment constitutes a reinforcement joint unit. Also, in the above embodiment, the lower column main reinforcement bars 7 and upper column main reinforcement bars 8 were embedded in the lower column member 3 and upper column member 4, respectively, but they may be connected by the sleeve joint 10 in an exposed state. Furthermore, each configuration of the above embodiment may be combined with one another. In addition, the specific configuration, arrangement, quantity, material, manufacturing method, etc. of each member or part can be changed as appropriate without departing from the spirit of the present invention. On the other hand, not all of the components shown in the above embodiment are necessarily essential, and can be selected as appropriate. [Explanation of symbols]

[0052] 1. Stopper (First Embodiment) 10 Sleeve joints (reinforcement bar joints) 15 Grout outlet 16 pipes 18 Sleeve joint unit (reinforcement bar joint unit) 20 Main body 20a rear end 20b front end 21 Engaging part 22 Male screw (first embodiment) 101 Stopper (Second Embodiment) 122 Male screw (second embodiment) 201 Stopper (Third Embodiment) 222 Male screw (third embodiment) D1 Mountain diameter D2 Inner diameter

Claims

1. A grout-filled reinforcing bar joint having a grout outlet, A pipe connected to the grout outlet, A reinforcing bar joint unit comprising a stopper fitted to the aforementioned pipe, The aforementioned stopper, The main body has a truncated cone shape, The main body has a male screw provided on its outer circumferential surface, A reinforcing bar joint unit characterized in that no female threads are formed on the inner surface of the pipe, a space is formed between the valley of the male thread and the inner surface of the pipe, and the space serves as a passage for discharging air from inside the pipe.

2. The reinforcing bar joint unit according to claim 1, characterized in that the stopper is formed from resin.

3. The reinforcing bar joint unit according to claim 1 or 2, characterized in that the stopper further has an engaging portion provided at the rear end of the main body.

4. The reinforcing bar joint unit according to claim 3, characterized in that the engaging portion is a projection that protrudes from the rear end of the main body and has a non-circular outer surface.

5. The reinforcing bar joint unit according to any one of claims 1 to 4, characterized in that the male thread is a tapered thread.

6. The reinforcing bar joint unit according to any one of claims 1 to 4, characterized in that the male screw is a parallel screw.

7. The reinforcing bar joint unit according to any one of claims 1 to 6, characterized in that the male screw is a double-threaded screw.

8. The reinforcing bar joint unit according to any one of claims 1 to 7, characterized in that the hardness of the stopper material is the same as or harder than the material of the pipe.

9. The reinforcing bar joint unit according to any one of claims 1 to 8, characterized in that the thread diameter of the male screw at the front end of the main body is smaller than the inner diameter of the pipe.

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