JP3775729B2 - Reinforcing bar crimping device and method for crimping the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reinforcing bar crimping apparatus and a crimping method for a reinforcing bar joint.
[0002]
[Prior art]
As is known in the art, the joint structure of a reinforcing bar is inserted into the steel pipe sleeve 2 at the tip end of the reinforcing bar 1 as shown in FIG. 1, and the diameter of the steel pipe sleeve is reduced and crimped with the reinforcing bar in the circumferential direction. The two ends of the joint screw 3 are connected to the female thread engraved on the inner peripheral surface of the steel pipe sleeve by attaching the open ends of the sleeve to each other. It is a thing.
[0003]
By the way, when the steel pipe sleeve 2 and the reinforcing bar 1 are bonded and integrated, there are a swaging machine and a hydraulic pressure bonding machine as driving sources for reducing the diameter of the steel pipe sleeve. In this swaging machine, the diameter of the steel pipe sleeve is reduced. It is performed by repeated hitting with a die (die), and it has excellent adhesion to the reinforcing bar, but the equipment cost is several times higher than that of the hydraulic pressure bonding machine, which increases the manufacturing cost of the reinforcing bar joint.
[0004]
Next, as shown in FIG. 4 (A), the first conventional example in which the steel pipe sleeve is reduced in diameter by a hydraulic crimping machine and crimped to a reinforcing bar is positioned up and down and moved by a hydraulic crimping machine. In the die 7, semi-circular concave portions 61 and 71 are formed in the respective die so as to face each other. The recesses 61 and 71 have a semicircular curved surface with the same curvature on the entire inner peripheral surface. The curved surface shape of the inner surfaces of the recesses 61 and 71 is smaller than the outer shape of the steel tube sleeve 2, and the curved surface shape and curvature are the outer shape of the reinforcing bar 1 and the inner diameter of the inner peripheral surface of the steel tube sleeve 2 to be crimped thereto. On the basis of the gap with the sleeve, it is determined in advance by calculation so that the steel pipe sleeve is completely crimped. Therefore, the steel tube sleeve 2 with the tip of the rebar 1 inserted in a predetermined dimension is inserted into a position corresponding to the recesses 61 and 71 of the upper and lower dies 6 and 7. Therefore, as shown in FIG. 4 (B), the upper and lower dies 6 and 7 are brought close to each other by the repulsive force of a hydraulic crimping machine (not shown), and the steel pipe sleeve 2 is reduced in diameter so as to be crimped to the rebar 1. .
[0005]
However, in this conventional method, the protruding portions 2a and 2a project to the left and right at the control position of the steel pipe sleeve. Therefore, when both the dies 6 and 7 are released and the steel pipe sleeve 2 that is crimped to the reinforcing bar 1 is taken out, as shown in FIG. Flange-shaped protrusions 2a and 2a are formed along the center direction. This is not only a problem that the protruding portions 2a and 2a are formed, but also a problem in the adhesion between the steel tube sleeve 2 and the reinforcing bar 1, and sometimes a gap remains between the steel tube sleeve and the reinforcing bar, and the crimping force is reduced. May cause a drop.
[0006]
Next, a second conventional example in which the steel pipe sleeve 2 is crimped to the reinforcing bar 1 by a hydraulic crimping machine will be described. As shown in FIG. 5A, the dies 8. It is installed in four directions, and an inner surface arc-shaped recess 81 is formed at each of the four dice facing each other. Therefore, as in the first conventional example, the steel tube sleeve 2 with the tip of the rebar 1 inserted in a predetermined dimension is inserted into a space surrounded by the concave and convex portions 81 of the upper, lower, left and right dies. Put. Therefore, when the four dies 8 on the top, bottom, left and right are simultaneously brought close together by the repulsive power of the hydraulic mechanism and the diameter of the steel pipe sleeve 2 is reduced, as shown in FIG. The projecting portion 2b... Has a shape with a 90 ° angular displacement on the outer periphery. Therefore, the phase is shifted again by shifting the phase by 45 degrees. Still, the outer shape of the steel pipe sleeve 2 is a polygonal shape, so that the crimping operation is performed for the third time by returning to the original position. Furthermore, such a crimping operation may be repeated. As described above, in the second conventional example, a polygonal shape remains even if the crimping operation is performed at least three times, and the number of crimping operations is large.
[0007]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a reinforcing bar crimping apparatus and a crimping method thereof in a reinforcing bar joint in which a steel pipe sleeve is completely crimped to a reinforcing bar by a crimping operation with few dies, and the outer shape of the steel pipe sleeve is substantially circular. .
[0008]
[Means for Solving the Problems]
The first feature of the reinforcing bar crimping apparatus according to the present invention comprises a die for reducing the diameter of a steel pipe sleeve and crimping the steel tube sleeve to the reinforcing bar, a recess formed at a position facing the die, and a driving means for the die. The vicinity of the opening end of the concave portion is a substantially flat surface, and the shape of the flat surface is such that the extension line of the flat surface makes the steel pipe sleeve from the tangent point where the opening end of the die first contacts the steel pipe sleeve. It is displaced at an angle necessary to guide it into the recess. The substantially flat surface means not only a flat surface but also a substantially flat surface.
[0009]
The second feature is that the shape of the flat surface is angularly displaced within the range of 0 to 11 degrees from the tangent line at which the opening of the flat surface first contacts the steel tube sleeve. Is where you are.
[0010]
The third feature is that the shape of the inner surface of the recess is substantially arcuate. When there are two dies, the inner surface shape of the concave portion is a semicircular arc shape. When there are three or more dies, the inner surface shape of the concave portion is an arc shape. Further, what are the semicircular arc shape and the arc shape? An arc shape in an elliptical shape is also included.
[0011]
The fourth feature of the reinforcing bar crimping method according to the present invention is that the steel pipe sleeve is deformed into an elliptical diameter in the middle of the diameter reduction of the steel pipe sleeve, and then the steel pipe sleeve is crimped to the reinforcing bar.
[0012]
Furthermore, the fifth feature of the reinforcing bar crimping method is that the steel pipe sleeve is deformed in advance into an elliptical diameter, and then the steel pipe sleeve is crimped to the reinforcing bar.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, with reference to FIG. 2 and FIG. 3, an embodiment of the reinforcing bar crimping apparatus in the reinforcing bar joint according to the present invention will be described. In FIG. 2, dice 4 and 5 for reducing the diameter of the steel tube sleeve 2 and crimping the steel tube sleeve 2 to the reinforcing bar 1, concave portions 41 and 51 formed at positions facing the dice, and a hydraulic crimping machine as a driving means for the dice And mechanical press.
[0014]
The inner shape of the recesses 41 and 51 is not particularly limited as long as the diameter of the steel pipe sleeve 2 can be reduced, but in order to make the outer shape of the reduced diameter steel pipe sleeve close to a cylindrical shape, as shown in FIG. A semicircular arc is desirable. Near the open ends 42 and 52 of the semicircular arc-shaped recesses 41 and 51 are substantially flat surfaces. Therefore, the shape of the flat opening vicinity 42, 52 will be described in detail.
[0015]
The two dies 4 and 5 are installed in a vertically facing position relationship, and the point A where the open ends of the two dies first contact the steel pipe sleeve 2 is an angle from the horizontal line H passing through the center point O of the reinforcing bar 1. This angle has θ1, and this angle is 45 degrees or less, for example, in the range of 30 to 45 degrees. The flat surfaces of the dies 4 and 5 in the vicinity of the open ends 42 and 52 are formed such that the extension line L of the flat surface is an angle θ2 from the tangent S of the point A where the open end of the dies first contacts the steel tube sleeve 2. The angle must be within the range necessary to push the steel sleeve into the recesses 41 and 51.
[0016]
According to the results of experiments on the range necessary for the induction, the displaced angle θ2 of the shape of the open ends 42 and 52 that are the flat surfaces is such that the extension line L of the flat surfaces is the open ends of the dies 4 and 5. It is desirable to be within the range of 0 to 11 degrees from the tangent line S of the point A that first contacts the steel pipe sleeve. If the angle exceeds 11 degrees, the force with which the flat surfaces 42 and 52 push the steel pipe sleeve 2 into the recesses 41 and 51 is reduced, so that it is difficult to reliably guide the steel pipe sleeve into the recesses. This is because the possibility of forming a protruding portion is increased as in the conventional example.
[0017]
Next, a crimping method in which the reinforcing bar 1 is crimped to the steel pipe sleeve 2 by the reinforcing bar crimping apparatus in the reinforcing bar joint will be described with reference to FIG. 3. FIG. 3 (A) is the same as FIG. , 5 shows a state in which a state in which the distal end portion of the reinforcing bar 1 is inserted into the steel pipe sleeve 2 is set at a position corresponding to the concave portions 41, 51. Therefore, when the dies 4 and 5 are brought close to each other by a hydraulic pressure bonding machine or the like, the steel pipe sleeve 2 is surely pushed and guided into the recesses 41 and 51 by the vicinity of the openings 42 and 52 on the flat surface. As shown in B), first, the steel tube sleeve 2 is deformed into an elliptical diameter in the middle of the diameter reduction. Thereafter, as shown in FIG. 3C, when both dies 4 and 5 are brought closer, the steel pipe sleeve 2 is completely reduced in diameter and is crimped to the reinforcing bar 1. Then, when the dies 4 and 5 are released, as shown in FIG. 3 (D), the steel pipe sleeve 2 that is crimped to the reinforcing bar 1 and has a substantially cylindrical outer shape is obtained.
[0018]
Further, according to the present invention, when the diameter of the steel pipe sleeve 2 is reduced without forming a protruding portion, the steel pipe sleeve may be stretched and deformed by about 10% of the total length in the axial direction at the same time as the diameter reduction. The crimping area between the steel pipe sleeve and the reinforcing bar 1 is increased, and the crimping strength is further increased.
[0019]
In another embodiment of the method for crimping such a reinforcing bar joint, the steel pipe sleeve 2 is deformed in advance into an elliptical diameter with the end of the reinforcing bar 1 inserted, and this is shown in FIG. 3 (B). Thus, the same action and effect can be obtained by setting between the dies 4 and 5 and then pressing the steel tube sleeve to the reinforcing bar.
[0020]
【The invention's effect】
According to the present invention, to manufacture a reinforcing bar joint, the diameter of the steel pipe sleeve can be reduced by a crimping operation with a small number of dies, and this steel pipe sleeve has no protruding portion. Therefore, the steel pipe sleeve can be completely and firmly crimped to the reinforcing bar without any gap. When the inner surface shape of the concave portion of the die is a semicircular arc shape, the outer shape of the reduced diameter steel pipe sleeve is substantially circular.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a structure of a reinforcing bar joint.
FIG. 2 is a cross-sectional view showing a main part of a rebar joint manufacturing apparatus.
3 (A), (B), (C), and (D) are cross-sectional views showing respective steps of a method for manufacturing a reinforcing bar joint.
4A, 4B, and 4C are cross-sectional views showing a first conventional example of a reinforcing bar joint manufacturing apparatus and steps.
FIGS. 5A, 5B, and 5C are cross-sectional views showing a second conventional example of a rebar joint manufacturing apparatus and steps. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reinforcement 2 Steel pipe sleeve 4 Die 41 Recess 42 Flat surface near the opening end of the recess 5 Die 51 Recess 52 Flat surface O near the opening end of the recess Reinforcing center A A point where the die first contacts the steel pipe sleeve S Tangent line L at the point of first contact with the steel tube sleeve Extension line H of the flat surface near the opening end of the recess Horizontal line θ1 passing through the center point of the reinforcing bar Horizontal line passing through the center point of the reinforcing bar at point A where the die first contacts the steel tube sleeve Angle θ2 from H The displacement angle required to guide the steel pipe sleeve into the recess from the tangent of the point where the die first contacts the steel pipe sleeve

Claims (2)

The die comprises a die for reducing the diameter of the steel tube sleeve and pressure-bonding to the reinforcing bar, a recess formed at a position facing the die, and a driving means for the die.
The vicinity of the opening end of the recess is a substantially flat surface,
The shape of this flat surface is angularly displaced within a range of 0 to 11 degrees from the tangent line at which the opening of the flat surface first contacts the steel tube sleeve .
The first contact point is in a range of an angle of 30 to 45 degrees from a horizontal line passing through the center line of the reinforcing bar.   2. The reinforcing bar crimping apparatus in a reinforcing bar joint according to claim 1, wherein the inner surface of the concave portion is substantially arc-shaped.

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