JPS6299559A - Method and apparatus for press bonding of steel bar joint - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method and apparatus for crimping reinforcing bar joints.

<Prior art> In general, deformed steel bars are used as reinforcing bars in concrete construction, etc., but since these deformed steel bars have a certain unit length, reinforcing bar joints are required to make them longer than that. It is necessary to connect multiple reinforcing bars using A reinforcing bar joint is a sleeve made of a metal tube with a wire section on the inner peripheral surface at one end and a deformed steel bar inserted and crimped at the other end. This sleeve is loosely inserted into one end of the deformed steel bar j1. An extrusion method in which the diameter of the metal tube is reduced by shrinking the metal tube in the radial direction using a die, and its inner peripheral surface is crimped to the outer surface of the deformed steel bar, or a metal tube in which the deformed steel bar is loosely inserted. It was obtained by either an on-site crimping method, in which the material was crimped from the top and bottom or from the left and right using a die cut in half.

FIG. 8 shows a conventional example embodying the extrusion method. In this conventional example, a hydraulic cylinder 3 is fixed to one of the reaction force cradle 1.2 facing away from each other, and its operating ram moves forward and backward toward the other reaction cradle 2. installation possible,
A support rod 5 is attached to the end of the actuating ram 4 along the axis,
Opposed to the shaft 5, the other reaction force holder 2 has a die 6a.
A reinforcing bar 7 made of a deformed steel bar passes through the die block 6, and a sleeve 8 is loosely inserted into the tip of the reinforcing bar 7 facing the support rod 5.

A canopy frame 9 is screwed into one end of the sleeve 8 having a line portion. Therefore, if AJ + pressure cylinder 3 is moved to press the actuating ram 4 toward the die block 6 side, the sleeve 8
With the reinforcing bars 7 inserted, the canopy frame 9 is pushed by the support rod 5 into the die 6a, and the diameter of the sleeve 8 is contracted to match the diameter of the die 6a. Therefore, the inner surface of the sleeve 8 is pressed against the outer surface of the reinforcing bar 7.

Moreover, FIG. 9 schematically represents a conventional example embodying the on-site crimping method. In this conventional example, a sleeve 8 with a reinforcing bar 7 inserted through one end is sandwiched between two halves of dies 6b and 6c from above and below, and the two are pressed together with appropriate pressure.

<Problems to be solved by the invention> However, the former method, which uses a drawing die to take reaction force to the sleeve and perform extrusion processing, has a maximum of 11 possible problems.
Since 0 eka is determined by the material of the sleeve,
If the cross-sectional shape of the sleeve or reinforcing bar is elliptical or has a large diameter, poor crimping will occur with the specified die diameter, making it difficult to maintain the required strength. In order to maintain the required strength, it is sufficient to replace the die that matches the cross-sectional shape or dimensions of the sleeve or reinforcing bar each time, but this results in low work efficiency and lacks productivity.

In addition, in the latter method of pressure-welding two split dies, the sleeve is pressed from two directions, which may cause the sleeve to protrude outside from the joint of the dies, causing cracks or cracks in the sleeve. There were other problems, such as difficulty in getting it done.

<Means for Solving the Problems> The present invention provides a method and an apparatus for solving the above-mentioned problems. A plurality of divided die segments in a radial arrangement contacting each other in the longitudinal direction on the outer circumferential surface of the
Wedge with the die segment through the tapered surface.
This method of crimping a reinforcing bar joint is characterized in that the die segment is pressed in the radial direction of the sleeve by moving a die guide in the longitudinal direction of the die segment, thereby crimping the sleeve to the deformed steel bar. The device to carry out the method is such that a hydraulic cylinder is fixed to one of a pair of reaction force pedestals that are spaced apart from each other, and its operating ram is attached so as to be movable toward the other reaction force pedestal. A cylindrical die guide is fixed to the end of the ram, and a tapered surface is formed on the inner peripheral surface of the die guide to have a smaller diameter on the side of the actuating ram, and the axis of the actuating ram is formed on the other reaction pedestal. A through hole and a cylindrical base are provided coaxially with the cylindrical base, and a plurality of wedge-shaped divided die segments having a tapered surface in sliding contact with the tapered face are fixed to the cylindrical base so as to be movable in the axial direction. This is a crimping device for a reinforcing bar joint, characterized in that the die segment can surround the sleeve.

<Function> According to the present invention, the die segment moves centripetally by moving the die guide in the axial direction to contract the sleeve and press it to the reinforcing bar. To obtain a reinforcing bar joint which can cope with changes in the temperature, can sufficiently cope with variations in sleeves and reinforcing bars, and maintains a predetermined strength uniformly. Further, according to the device of the present invention, the sleeve in which the reinforcing bar is inserted is attached to the die segment supported by one of the reaction force pedestals in a gripping state,
When the hydraulic cylinder is actuated to push the working ram toward the die segment, the die segment fits into the die guide attached to the end of the working ram, and the tapered surface where both the die segment and the die guide slide into contact is formed. Through this, the die segment moves centripetally in the radial direction of the sleeve and the reinforcing bar, and the sleeve is crimped onto the reinforcing bar.

<Example> The drawing shows an example of the crimping device according to the present invention.
Once this apparatus is explained, the method of the present invention will be self-evident. FIG. 1 is a partially sectional side view, FIG. 2 is a plan view, FIG. 3 is a front view of the die guide, FIG. 4 is a sectional side view of the die guide, FIG. 5 is a perspective view of the die segment, and FIG. The figure is a side view of the die segment 1-, and FIG. 7 is a longitudinal sectional view of the die guide and the die segment in an operating state.

In FIG. 1 and FIG. 2, 10 is a base, 11.12 is a pair of reaction force pedestals spaced apart and facing each other on the base 10, and 13
is one reaction force pedestal] Hydraulic cylinder fixed to 1, 1
4 is the operating ram of the hydraulic cylinder 13, 15 is the operating ram 1
4, a mounting plate fixed to the outer end of the die guide 16, a die guide detachably attached to the mounting plate 15, 17 a support plate detachably attached to the front surface of the die guide 16, and 18 a reaction force of the other side. A cylindrical stand fixed to the pedestal 12, 19 is a cylindrical stand 18
20 is a tie rod that connects the reaction force pedestals 11 and 12 to slide and guide the support plate 17, and 2I is a motor that drives the hydraulic pump 22.

To explain the die guide 16 with reference to FIGS. 3 and 4, a substantially cross-shaped through hole is formed along the axis of a metal cylinder 16a having an axial length that is the same as or slightly longer than the length of the sleeve to be processed. A through hole 16b is bored through the hole 16h, and the through hole 16h has a tapered surface 16c that slopes from one end to the other end. This tapered surface 16c is formed by the bottom surface of a dovetail groove 16d having a constant depth. At the base of this dovetail groove 16d, a vertical surface 16e parallel to the axis,
16[ is formed from one end to the other end. The vertical surfaces 16e face each other between the dovetail grooves lad, and the vertical surfaces 16e
6f faces the axial center. The cylindrical metal 16a is fitted and fixed to the cylindrical metal 16g by shrink fitting. The cylindrical metal 16g has screw holes 16h for mounting on the mounting plate 15 and the support plate 17. Reference numeral 16i denotes a screw hole for suspending the die guide 16 when fixing it to the mounting plate 15 and the support plate 17 by screwing together an eye bolt.

Next, with reference to FIGS. 5 and 6, die segment 1
9, the dovetail groove +6 of the die guide 16
It has a wedge-shaped body 19b made of a metal body having a fitting part 19a which can be fitted into and slidable on the cylindrical base 18 of the reaction force receiving base 12, and an engaging part 19c which is removably engaged with the cylindrical base 18 of the reaction force receiving base 12.

The upper surface of the fitting portion 19a forms a tapered surface 19d having the same inclination angle as the tapered surface 16c, and a wedge-shaped body 19b.
The lower surface is a concave surface 19 parallel to the axis of the die guide 16.
e, and the side surface can face the vertical surface 16e of the die guide 16. The concave surface 19e has a curvature equal to or less than the curvature of the standard outer diameter of the sleeve to be machined. The engaging portion 19c is provided with a groove 1.9f formed in a direction perpendicular to the fitting portion 19a, and this groove 19f is movably connected to the cylindrical base 18 in a direction perpendicular to the axis of the die guide 16. engage.

As shown in FIGS. 1 and 2, the cylindrical base 18 that engages the die segment 19 has a total of four dovetail-shaped dovetails at symmetrical positions in the vertical and horizontal directions on the annular body 18a coaxially facing the die guide 16. A recessed portion 18111 is formed.

The dovetail recess H1b is the engaging portion 19 of the die segment 19.
The die segment 19 can be moved in the axial direction of the annular body 18a.

Therefore, to explain the operation of the above embodiment, as shown in FIG. 7 and position the sleeve 7 in the center of the four die segments 19, then the hydraulic cylinder 13
is operated to move the actuating ram 14 toward the reaction force cradle 12. Due to the movement of the actuating ram 14, the die guide 16 moves toward the die segment 19 together with the support plate 17, and the die segment L9 completely enters the through hole 1.6b of the die guide 16, leaving the engaging portion 19c. . At this time, the die segment 19 moves in the radial direction of the sleeve 8 due to the cooperation of the tapered surface 16c of the die guide J6 and the tapered surface +9d of the die segment 19.
The die segments 19 each approach the sleeve 8 centripetally, and their respective concave surfaces L9e contact the sleeve 8 to press the outer circumferential surface of the sleeve 8 in the radial direction. Therefore, the wall thickness of the sleeve 8 is pressed against the reinforcing bar 7,
The inner circumferential surface of the sleeve 8 is pressed against the uneven surface of the reinforcing bar 7, and the sleeve 8 does not come off from the reinforcing bar 7.

In this way, when the drawing process of the sleeve 8 is completed, the actuating ram 1
4 for the length of the sleeve 8 or slightly to release the suppression of the die segment 19, and the reinforcing bar 7 is pulled out from the opening 12a, and the machining is completed. In this way, since the sleeve 8 is centripetally pressed from four locations in the radial direction, the wall thickness of the sleeve 8 may protrude between the die segments 19, but when such a situation occurs, the original From the state at the time of machining, the sleeve 8 is 90 degrees centering on its axis.
The protruding portion can be pressed by rotating it once again and performing the same process as above. Although four die segments 19 are arranged, three, five, or six dice segments may be arranged, and the die guide 16 may be arranged in accordance with the number of dice segments 19.
The dovetail groove lad may be formed as appropriate. Further, the die segment 19 and the die guide 16 have a dovetail groove 16d.
and a fitting portion 19a having a complementary shape, which causes the die segment 19 to move centripetally toward the sleeve 8 when the die guide 16 is pulled away from the die segment 19. This is not necessarily a necessary configuration in principle, since the purpose is to prevent this from occurring and to prevent any hindrance from occurring when the sleeve 8 is pulled out or inserted from the die segment 19. Further, a metal plate for reducing friction may be interposed between the tapered surfaces L6c and t9d.

<Effects of the Invention> According to the present invention described above, the plurality of die segments are mutually connected to the die guide through the tapered surface so that they can surround the sleeve and move centripetally in the axial direction of the sleeve. By moving the die guide in the axial direction, the die segments can press or release the pressure on the sleeve, so that the die segment's ``hoop'' can be adjusted each time depending on the cross-sectional shape of the sleeve or reinforcing bar or changes in winter. Since the amount of movement in the radial direction can be changed, a reinforcing bar joint having a predetermined strength can be obtained regardless of the cross-sectional shapes of the sleeve and reinforcing bars, which vary widely. (However, since the die segment moves centripetally through the tapered surface, the diameter of the drawing process can also be changed, so it is not only possible to draw a sleeve of a specific diameter, but also to have its upper and lower limits. It is also possible to draw sleeves of other types and can be used as a general-purpose device.Once a sleeve is drawn with a conventional die, it is impossible to draw it again with the same die. However, according to the present invention, since the die segment can be moved centripetally, the drawing process can be performed at least twice, and the compression strength between the sleeve and the reinforcing bar can be improved accordingly. Since the die guide moves toward the sleeve rather than pushing itself toward the die, there is no need to attach a canopy to the sleeve, and processing can be performed immediately by simply inserting the sleeve loosely into the reinforcing bar. According to the present invention, the operating stroke of the hydraulic cylinder is determined by the angle of the tapered surface formed on the die segment and the die guide. In some cases, the length may be less than about half of the length, so the driving of the hydraulic nolinder becomes economical, and the machining time can be shortened accordingly.

[Brief explanation of drawings]

1 and 2 are a partially sectional side view and a plan view showing a crimping device according to the present invention, and FIG. 3 is a front view of a die guide.
4 is a cross-sectional side view of the die guide, FIG. 5 is a perspective view of the die segment, FIG. 6 is a side view of the die segment, FIG. 7 is a longitudinal sectional view of the die guide and the die segment in the operating state, and FIG. 9 and 9 are explanatory diagrams of a conventional example. 1.1.12・Reaction force cradle, ■3...Hydraulic cylinder,
14... Operating ram, 15... Mounting plate, 16... Dice guide, 16c. 19d・Tapered surface, 18・Cylindrical base, 19・Dice segment. Figure 4

Claims (2)

[Claims] (1) The outer peripheral surface of the sleeve with the deformed steel bar loosely inserted into one end,
A method for crimping a reinforcing bar joint, characterized in that a plurality of radially arranged die segments move centripetally in the radial direction of the sleeve to press it, thereby crimping the sleeve to a deformed steel bar. (2) A hydraulic cylinder is fixed to one of a pair of reaction force pedestals that are spaced apart and facing each other, and its operating ram is attached so that it can move forward and backward toward the other reaction force pedestal, and a cylinder is attached to the end of the operating ram. a shaped die guide is fixed, and a tapered surface having a smaller diameter on the operating ram side is formed on the inner circumferential surface of the die guide,
The other reaction pedestal is provided with a through hole coaxial with the axis of the actuating ram and a cylindrical pedestal, and the cylindrical pedestal includes a plurality of wedge-shaped divided pieces each having a tapered surface that slides in contact with the tapered surface. A crimping device for a reinforcing bar joint, characterized in that a die segment is fixed movably in the axial direction, and the die segment can surround a sleeve.