JPS6049815A - Bending device of straight pipe - Google Patents

Abstract

PURPOSE:To make the operation of bending work and the taking-out of a formed product easy by arranging oppositely a pair of outer dies, having each a die face having a semicircular cross section and a concentric curvature, and providing a core die, having a die face conformed to one side of the outer die faces, freely capably to go into or out of the space of the outer dies. CONSTITUTION:Respective outer dies 1, 2 having die faces 1a, 2a having each a semicircular cross section and a face curved with a concentric O curvature, are arranged oppositely, and one end of a core die 3 having a die face 3a conformed to the die face 1a is fixed to an arm 4 pivotally attached to a shaft having a center O. Next, after inserting a blank material (a) between the dies 1, 2 in a state that the die 3 is separated from the space between the dies 1, 2; the die 3 is inserted into the inside of material (a) by turning the die 3 between them, to fix the other end of die 3 to a supporting arm 6. When the die 2 is moved toward the die 1, the lower half part of material (a) is pressed against the die face 1a by the die 3 and is bent along the die face 1a, and also the upper half part of material (a) is bent along the die face 2a, then an elbow- shaped blank material (a) is formed. In this way, the operation of bending work and the taking-out of a formed product are easily performed, and the production efficiency is improved.

Description

[Detailed Description of the Invention] The present invention can be used to form an elbow by bending a short straight pipe, or by opening the end of the straight pipe in any direction. This invention relates to a straight pipe bending device for bending, etc.

Conventionally, the sum of a straight pipe is curved to a predetermined curvature6.
One end of the mold is fixed, and the end of the straight pipe is press-fitted from the other end through the outer mold, and the pipe can be bent depending on the distance between the mold and the outer mold, or in the case of a straight pipe, press processing etc. It is common practice to form an elbow with a predetermined curvature by combining two gutter-like members that are curved into a straight arc, but in the former case, it is necessary to press fit a straight pipe into a core mold. Because the straight pipe experiences significant frictional resistance on its inner and outer surfaces, it requires a large amount of power to apply pressure, and it is also necessary to heat the mold 6 to a high temperature.Furthermore, special care is required when pulling out the curved pipe from the stone slab after forming. In the latter case, it is necessary to align the two members facing each other and weld the joining edges on both sides. , the processing was extremely complicated.

The present invention aims to eliminate the above-mentioned disadvantages of the conventional method, extremely simplify the bending operation and take out of the molded product, and improve production efficiency. A pair of outer molds having arc-shaped mold surfaces, the mold surfaces facing each other, at least one of which is movable relative to the other, and one end of an arc-shaped stone mold having a mold surface that matches the mold surface of either one of the two outer molds. is fixed to an arm piece that can be rotated and fixed to one of the outer molds around the center of curvature of the mold surface of the outer mold, and the stone mold fixed to the arm piece is attached to the outer mold of the pair. It is characterized by being provided so that it can be moved in and out of the interval.

Embodiments of the present invention will be explained with reference to the drawings, and FIGS. 1 to 8 show a process in which a short straight pipe is used as a material a and is bent into an elbow of a desired curvature.
As shown in the figure, straight pipe material is cut along a line that is inclined to the axis and the length is 4ft! Obtain a material a that is trapezoidal on one side. By cutting the material a into a predetermined trapezoid shape in this way, an elbow with well-shaped openings at both ends can be obtained by bending.

Straight pipes can be used economically without waste, but when shaping the openings at both ends after bending, the pipes may be cut into short straight pipes of predetermined dimensions instead of into trapezoids.

The device for bending the material a is a pair of outer molds.
+21, and a stone type (3) that can appear between the extranuclear type +1lf21.

The outer mold fllf2+ has a semicircular cross section and a concentric curvature of 0'
It has large and small gutter-like mold surfaces (lad (2a)) that bend rt, and these mold surfaces (la) (2a) of the outer mold +11 (2+) are made to face each other, while, for example, in the illustrated example, the outer mold ( la)
is fixed, and the other outer mold (2) is moved using, for example, hydraulic pressure or an electric motor. If necessary, it may be possible to move both the hermaphrodite molds 111+21, so that when the hermaphrodite molds 111+21 are matched, a space corresponding to the external shape of the elbow with the desired curvature is formed by the mold surfaces (la) and (2a). It was to so. The stone mold (3) has each mold surface (la) (2) of the outer ff1ll1121.
a), and its cross section is as shown in FIGS.
2 a) A semicircular mold surface (3
a) K was formed. In the illustrated example, the curved outer surface of the arc-shaped stone mold (3) is used as the mold surface (3a), and this is used as the mold surface (la) of the outer mold (11).
) is shown.

In addition, the other half of the cross section of the stone mold 13) and the semicircular mold surface (3)
Appropriately remove the flesh on both sides of a), and when inserting the stone mold (3) into the straight pipe material a located between the outer molds fi++21 during the bending process described later, the central axis of the material a and the stone mold ( 3
), so that the large diameter portions on both sides of the stone mold (3) do not interfere with insertion.

As shown in Fig. 1, the stone mold (3) rotates one end of the stone mold (3) about the center of curvature of the mold surface (2a) of the #outer mold (2) with respect to one of the external temperatures (2). Fix the arm piece (4) immovably with a bolt or the like to the free end of the arm piece (4) with the shaft attachment (5) attached so that the arm piece (4)
According to the rotation of 4), the stone mold (3) is rotated so that it can appear and retract with the same curvature in the curve of the outer mold 111t2+, and integrally with the movable outer mold (2) relative to the other outer mold 111. Made it possible to move it.

In the above apparatus, as shown in FIG.
) are separated from each other, and with the core m (31 removed from between both m + 11 and t21 and waiting in the inoperative position, the above-mentioned material a is charged between the outer m + 11 and 21 as shown in Fig. 2). Hold it, then move Ishiya (3) from the standby position to both types f.
Rotate between il 121 and insert into material a, visit Ic?
The support arm (6) has the other end of the mold (3) attached to the movable outer mold (2).
) with bolts, etc.

If the movable outer mold 12) is moved toward the other outer mold (1) from this state, the lower half of the material a shown in FIG. The processing by the moving mold 4 (3) curves along the mold surface (lal) of the outer mold (11), and also removes the upper half of the material a, so that the mold surface (2a) of the outer mold (2) The material a is molded into an elbow shape, so next, untie it from the support FIlit 61, rotate the arm piece, and mold the stone mold (3) into an elbow shape as shown by the phantom lines in the figure. Take out the bow 1 from inside a and insert the movable outer mold (2) into the outer mold (1
) to the outside temperature 111.
Take it out from between +21 and finish bending it.

When forming an elbow according to the present invention, it may be difficult to form a 90° elbow from a straight pipe material at once depending on the type of material or the thickness of the material. There are cases where the crab is bad, but in this case, first of all, make an outer mold with a mold surface (la), (2a), (3a) with a large curvature as shown in Figure 3, such as 1/i that is easy to bend.
+21 and a stone mold (3) are used to form the product, and then this molded product is used as a raw material and further molded into an outer mold and a stone mold that have a mold surface with a small curvature, and the curvature is gradually reduced. By using a small amount of power, the bending process can be performed reliably at the desired angle by forming the shape in stages, as shown in Figures 4 and 5. Of course, when dealing with materials such as steel pipes, it is possible to perform 90° L7+ from straight pipes all at once. It can be molded into any shape, and there is no limit to the number of times it can be molded.

In addition, for molded products that require high accuracy in the inner diameter, after the above molding operation, the molded product is held by the outer mold +11+21 and a spherical orthopedic stone is tied to the tip of the arm piece (4). By forcibly rotating the arm piece (4), the shaping mold can be press-fitted into the molded product and the inner diameter can be finished.

Next, FIG. 11 and FIG. 12 show the case where the end of a straight pipe is bent. In the example illustrated above, the material pipe a has the end of the straight pipe curved at a substantially right angle, but the end of the curved part is further bent. An example is shown in which the end of a straight pipe is bent three-dimensionally, and the end of the curved part is bent on each mold surface (
la) (2a) Introducing the straight pipe into a bending device consisting of an outer mold 111f2+ having e and a stone mold (3) having an arc-shaped mold surface (3a), holding the straight pipe immovably with a fixing member (7), As in the previous example, by moving one outer mold (2) toward the other outer mold (1), the curved end of the raw material tube a is further curved, and in the illustrated example, the stone mold is solid. For the outer mold (1) on the other side, it is fixed to an arm piece (4) that rotates around the center of curvature 0 of the mold surface (1a), and the center m + a + is set to the outer mold +1lt21
With the arm piece (4) inserted into the operating position between them, the arm piece (4) is locked to the pin (8) by eccentric teeth with respect to its rotation axis (5), so that the sixth axis (3) is immovably fixed; The outer mold surface (3a) and the mold surface (2a) of the outer mold (2) bent the end of the moon tube a to a predetermined curvature. In this case, it is optional to perform the bending stepwise to achieve the desired curvature as in the previous embodiment, and furthermore, by freely setting the fixed positional relationship of the material tube a with respect to the bending device. As shown in 141M, the bending angle α of the terminal part of the ct'l a, and the bending terminal by this α can be further bent in any direction at the bending angle β, making it possible to form a so-called three-dimensional bend at the end of the tube. Since it is possible to form a curved section without a connecting section, it is possible to prevent the drawbacks such as leakage accidents at the connecting section, which occur when the curved section is formed using another curved pipe material such as an elbow. Another advantage is that troublesome curved pipe connections can be omitted during piping work.

As described above, according to the present invention, an elbow can be easily formed by bending a short straight pipe, or a seamless curved part can be easily formed or three-dimensionally bent by bending the end of a straight pipe. In this method, a monthly tube is positioned between a pair of outer molds, and one outer mold and the stone cutter are moved relative to the other to perform molding, so the bending resistance of the material is reduced in the same way as in conventional press working. The stone mold can be processed with a small amount of power, and the stone mold is curved into an arc with a curvature concentric with the wave surface of the outer mold, and this is rotated around the center of curvature of the mold surface on one side of the outer mold. Because it is tied to a moving arm piece, insertion into the material tube during processing and de-asphalting operation after forming are smooth.Since it is extremely easy to insert and remove the material tube, work efficiency is significantly improved, and cold It has effects such as being suitable for work.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view, FIG. 2, FIG. 3, FIG. 4, and FIG. 1 is a side view, FIG. 7 is a sectional view taken along the line ■-■ in FIG. 2, FIG. 8 is a sectional view taken along the line ■-■ in FIG. FIG. 10 is a perspective view of the molded elbow, FIGS. 11 and 12 are sectional views showing other embodiments, and FIG. 13 is the X1ll- of FIG. 11.
The sectional view taken along the line Xll and FIG. 14 are perspective views of the curved portion at the tip of the straight pipe. fil 121 ... Outer mold (lal (2a) - mold surface (3) ... Core 'IIL (3a) ... Stone mold surface 14) ... Arm piece (5) ... Arm piece The rotation axis a...
Material pipe Figure 9 Figure 10

Claims (1)

[Claims] A pair of outer molds having semicircular cross-sections and large and small arc-shaped mold surfaces with a predetermined concentric curvature, the mold surfaces facing each other so that at least one of them is movable relative to the other, and either one of the mold surfaces of the bisexual mold One end of the six arc-shaped molds having a mold surface that matches is fixed to an arm piece that can be rotated and fixed to one of the outer molds around the center of curvature of the mold surface of the outer mold. ,
A straight pipe bending device characterized in that a mold 6 fixed to an arm piece can be moved in and out of the gap between a pair of outer molds 111121.