JPS61255725A - Elbow production and device for forming multiple bent pipe for production - Google Patents

Abstract

PURPOSE:To increase a forming accuracy and to reduce the cost by press- forming a blank pipe with the upper and lower divided dies providing wavy forming face and by forming with bulging with compressing the blank pipe in an axial direction. CONSTITUTION:The upper die 1 is divided into die pieces 1a-1c and supported freely movably by the upper part guide rail 10. By the connecting integration of these three die pieces a semi-circular recessed groove 2a is formed on the lower end face so as to coincide with the upper half part at the outside of the blank pipe P. The lower die 3 is divided into die pieces 3a-3d, supported by the lower part guide rail 11 and a recessed groove 4a is formed by the integration of the four die pieces. Pressing bodies 5, 5 are compressed with equal force and same speed from both sides simultaneously with closing the upper and lower dies 1, 3. In this case a bulging formation is performed by applying a hydraulic pressure from the inner part. The forming accuracy is thus increased and mass production can be performed, so the production cost can be reduced.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an elbow manufacturing method and a molding device for manufacturing multiple curved pipes, and more specifically, to a method for simultaneously manufacturing a large number of elbows having the same curved shape with a desired curvature. The present invention provides a method for manufacturing an elbow, and an apparatus for molding a multi-curved pipe in which curved portions are alternately and continuously molded into a regular waveform.

[Technical background of the invention and its problems] Conventionally, elbows have been manufactured using plate material or tube material.

In the case of the former plate material, a plate material such as a steel plate that has been cut to the desired elbow expansion size is bent into the shape of the elbow and the joints are welded.In the case of the latter pipe material, for example, There is a mandosil forming method in which a straight pipe is passed straight through the curved part of a mandrel and bent while expanding.
Various techniques have been disclosed for J', such as the so-called high-frequency forming method in which local heating is performed using high-frequency waves to perform drawing or pressing bending.

However, with such technical means, BL misalignment requires complicated and troublesome equipment, advanced molding technology, and the process to produce a product is not without difficulties, resulting in failure and failure. There were also disadvantages in terms of product accuracy, such as the tendency for wrinkles to form, and there was also an economical problem as it was unsuitable for mass production.

[Object of the Invention] As a means to solve the above-mentioned problems, the present invention uses a fixed-length tube of a predetermined length as a master tube, and uses a molding method in which the molding surface of the two molds is formed into a regular waveform by using a mold that is divided into upper and lower molds. At the same time, the original tube is compressed in the axial direction from both ends of the tube, and a bulge is formed inside the original tube using hydraulic pressure, thereby forming a curved part with the same curvature in the axial direction. A multi-curved pipe is formed by alternating and continuous forming into a regular waveform to form a perfect circular cross section with approximately the same thickness and diameter as the original pipe. The purpose is to manufacture a large number of 90-degree or 45-degree elbows at the same time by sequentially cutting in the diametrical direction perpendicular to the perpendicular axis.

[Summary of the Invention] In describing the present invention in detail, an embodiment of a multi-curved pipe forming apparatus for manufacturing an elbow of the present invention will first be described with reference to the drawings.

The mold constituting the molding apparatus of the present invention is a top and bottom split mold,
The upper mold 1 has three mold pieces 1a in the center and on both sides.

These mold pieces are movably supported by the upper rail 10, and the molding surface 2 at the lower end has a concentric curvature due to the three mold pieces being connected and integrated into one. It is formed to have a series of waves, and a semicircular groove 2a that matches the upper half of the outer surface of the original tube P is provided at the center along the forming surface (-).

The lower mold 3 has four mold pieces 3a, two in the center and two on both sides.
3b, 3c, and 3d, which are movably supported by a lower mold rail 11 like the upper mold 1, and by connecting and integrating these four mold pieces, the molding surface 4 at the upper end is the same as that of the upper mold 1. Like the molding surface, it is formed to have a series of waves with concentric curvature, and a semicircular recess $4a is provided in the center of the molding surface to match the lower half of the outer surface of the original tube. When the mold 1 is clamped, the molding surfaces 2.4 of both molds are perfectly aligned as shown in Fig. 1, and a perfect circle is formed by both grooves 2a and 4a, which is uniform with the entire outer surface of the master tube. 5 consists of b
do.

Further, on the backs of the split mold pieces 3a and 3d on both sides constituting the lower mold 3, there is a support recess 6.6 for gripping both ends p/, p/ of the original pipe P in a helmet-like manner. A hydraulic injection hole in the center that communicates with the outside? , 7 are mounted in a fixed or removable manner, and both the pressing bodies 5.
When both the upper and lower molds 1 and 3 are clamped by the upper front regulating part 9.9 of 5, the connected and integrated width of the divided mold pieces 1a, lb, lc of the upper mold 1 is the divided mold piece 3a, 3b of the lower mold 3, 3c, 3d
The length should be the same as the joint integrated width of 5 and b.

The reference numeral 8 in the figure is an airtight material such as an O-ring for preventing hydraulic leakage, which is interposed in the support recess circle at the end of the original tube of the pressing body.

PI & again! With multiple bent pipes, P2 is a 90 degree elbow, P
3 is a 45-degree elbow, and C1♂ indicates a cutting line for obtaining each of the above-mentioned elbows displayed on the multiple curved pipe. Further +
1 and d' indicate the arrangement interval between the upper and lower mold pieces before the press drive.

Thus, as mentioned above, the device of the present invention can
Three split mold pieces la, ]-b, movably supported by
An upper mold 1 consisting of an LC, and four divided mold pieces 3a, 3b, 3c similarly movably supported on a lower mold rail 11.
, 3d, the molding surface 2 at the lower end of the winter mold piece of the upper mold 1 and the molding surface 4 at the upper end of each mold piece of the lower mold 3 are interconnected and integrated, and After both the upper and lower molds 1.3 are clamped, the curved portions of the required curvature are formed into a regularly continuous wavy shape, and at the center of the molding surface 2.4, a mold is formed along the wavy shape. Semicircular grooves 2a each coincide with the outer surface of the original tube P.

4a, and further split mold pieces 3 located on both sides of the lower mold 30.
An axial pressing body having a support recess 6.6 for airtightly gripping both ends pl and pl of the master tube and a hydraulic injection hole 7.7 for applying internal pressure into the master tube on the back of a and 3d. 5.5 is installed.

Therefore, first, a fixed length tube of a predetermined length is prepared as the master tube P. The fixed length tube corresponds to the length of the multiple curved tube to be molded plus the tube end on the image side held by the support recess of the pressing body.

Next, as shown in FIG. 7, the upper mold 1 is raised and separated from the lower mold 2 into a completely open state, and at the same time, the split mold pieces 3a and 3d located on both sides of the lower mold 3 are moved backward. Move to (
(backward) so that both ends P', P' of the original tube P are held in the support recess 6.6 of the pressing body 5.5 in an airtight manner.

In this case, since the pressing body 5.5 is fixedly or removably attached to the back of the mold pieces 3a, 3d and attached to the V, the original tube is gripped by moving the position of this mold piece. Or, alternatively, only the pressing body is molded by a driving mechanism such as a hydraulic cylinder (not shown) connected to the pressing body 5.5 on the pipe end y of the original pipe P supported on each split mold piece. Piece 3
It is also possible to advance it to the back of parts a and 3d and press fit it into the support recess 6.6.

Then, depending on the length of the original pipe P mentioned above, the two central split mold pieces 3b and 3c are arranged with a distance d' between them, and also in the upper mold 1, each of the two pressing bodies is spaced within a distance of 5.50 mm. Split mold pieces 1a, l
They are arranged with a distance d between them so that b and lc are located.

The time period wid, d' suitable for the arrangement of each of these split mold pieces is determined by the pressurizing force with which the pressing body 5.5 presses the original tWP in the axial direction, the accompanying speed, and the upper mold 1 which descends while being adjusted with this. The press load force and mold clamping speed, etc., move smoothly toward the center in synchronization with these panes, and when the final mold clamping is completed, each divided mold piece 1a.

The arrangement intervals are adjusted so that lb, lc, 3a, 3b, 3c, and 3d are connected to each other and integrated.

Simultaneously with the clamping of the upper mold 1, the pressing bodies 5.5 are pressed and propelled in the axial direction from both sides of the raw tube P with equal force and at the same distance, compressing the raw tube. In order to prevent the collapse and buckling phenomenon of the original tube P, there is an injection hole 7 for a pressing body in the original tube.
．． From step 7, internal pressure is applied by hydraulic pressure, and while this internal pressure is maintained, it is compressed, and when the mold is completely clamped, the entire outside of the tube is covered! ! Bulge forming is performed using high hydraulic pressure so as to make perfect pressure contact with the I#2a and 4a surfaces, and the forming of the multiple curved pipe P1 is completed.

[Effects of the Invention] The multi-curved pipe P1 formed in this manner has regular curved portions with the required curvature corresponding to the molding surfaces 2.4 of the upper mold 1 and the lower mold 3 in the axial direction. It has a predetermined shape that is alternately continuous in a waveform, and in cross section, it has approximately the same thickness and diameter as the original tube P, and is a perfect circle that conforms to the grooves 2a and 4a, and does not buckle or wrinkle ( 1. High accuracy.

This multiple curved pipe P1 is essentially equivalent to a number of elbows of the same shape that are successively integrated into a wave shape.For example, as shown in FIG. Or, if cut along the diametrical cutting lines C and C' that are perpendicular to the semi-perpendicular axis, Figure 12 (A) CB) + 7)
A large number of 90 degree elbows P2 and 45 degree elbows P3 can be obtained at the same time.

That is, in the multiple curved pipe P1 of the embodiment shown in FIG.
90 degree elbow x 5) + (45 degree elbow x 2)'', a certain BL will be manufactured in large numbers of ``45 degree elbow x 12'' at the same time, but these quantities are for both upper and lower type 1.3. This is determined by the size of the split mold piece and the length of the master tube required for it, and there is no difficulty in the manufacturing process.

The elbow manufactured in this way has uniform dimensions and a good finish, and there is only a small amount of material lost at the end of the tube held by the pressing body, so the overall material yield is extremely high. Since it can be produced in large quantities in the cold, it is economical and can be provided at a low price, making an extremely large contribution to this field.

However, in the illustrated embodiment of the present invention, three split mold pieces of the upper mold and four split mold pieces of the lower mold (substantially the same size as the upper mold pieces) are used. Since there are two mold pieces and two mold pieces of half size, both the upper and lower molds are the same. mold piece,
The divided mold pieces of the upper mold were arranged to face each joint of the divided mold pieces of the lower mold, and the divided mold pieces of the upper and lower molds were made to have the same width, and the upper and lower mold pieces were made into a pair. It may be configured such that they are arranged oppositely.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view of the entire device in a state where a multiple curved pipe for manufacturing an elbow is molded. Figure 2 is a side view of the same. Figures 3 to 6 are
FIG. 3 is a sectional view taken along lines A-A, B-BlC-C, and D-D shown in the figure. FIG. 7 is a cross-sectional view showing the state at the start of multiple curved pipe forming when the mold is opened and the original pipe is cut. Figures 8 and 9
The figure is a sectional view taken along lines E-E and F-F in the previous figure. 10th
The figure is a cross-sectional view of a state in which a multi-curved tube of a predetermined shape is formed by clamping the mold and applying internal pressure by hydraulic pressure inside the original tube, with a portion of the tube end cut away. (Substantially, this corresponds to the cross-section of the full-size view in FIG. 1.) FIG. 11 is a full-size front view of the multiple curved pipe formed in the previous figure, showing a partial cross section. No. 12 [(A) and (B) are the 90 degree elbow and 45°
FIG. 3 is a front view showing a partial cross section of the degree elbow. [Explanation of symbols] 1 - upper mold, la, lb, lc - split mold piece, 2 - molding surface, 2a - semicircular groove, 3 - lower mold, 3a
, 3b, 3c, 3d ~ split mold piece, 4 ~ molding surface, 4
a~Semicircular groove, 5~pressing body, 6~support part, 7~hydraulic injection hole, P~original tube, y~end, P
1~Multiple curved pipe, P2~90 degree L 7g, P3~
45 degree elbow.

Claims (6)

[Claims] (1) A method of manufacturing many identical elbows at the same time, using a fixed length tube of a predetermined length as the master tube, which is divided into upper and lower molds, and the molding surface where the two molds join has a regular waveform. At the same time as press forming with a mold, the original tube is compressed in the axial direction from both ends of the tube, and at the same time, a bulge is formed inside the original tube using hydraulic pressure, thereby making a curved part with the same required curvature in the axial direction. A multi-curved pipe is formed into a perfect circular cross section with approximately the same thickness and diameter as the original pipe by alternating and continuous forming into a corrugated shape, and a right angle or semi-perpendicular angle is formed around each curved part of the multi-curved pipe. At the same time, many 90 degrees or 4
An elbow manufacturing method characterized by manufacturing a 5-degree elbow. (2) A multi-bent pipe forming device for simultaneously manufacturing a large number of identical elbows, which consists of an upper mold consisting of several split mold pieces movably supported by an upper guide rail, and a lower guide rail. The lower mold is made up of several split mold pieces that are also movably supported. When the upper and lower molds are connected and integrated, and the upper and lower molds are clamped, the same curved part with the required curvature is formed into a regularly continuous wave shape, and in the center of the molding surface, there are A semicircular groove that matches the outer surface of the original tube is provided, and a support recess that airtightly holds both ends of the original tube is provided on the back of the split mold pieces located on both sides of the lower mold. A forming device for a multi-bent pipe for manufacturing an elbow, characterized by a configuration in which an axial pressing body having a hydraulic injection hole for applying internal pressure to the elbow is attached. (3) In the molding apparatus according to claim (2), a divided mold piece of the lower mold is attached to each connecting portion of several divided mold pieces of the upper mold; A molding device for a multiple bent pipe for manufacturing elbows, characterized by a configuration in which split mold pieces of an upper mold are arranged to face each other at each joint. (4) The molding apparatus according to claim (2), characterized in that several split mold pieces of the upper mold and several split mold pieces of the lower mold are arranged so as to be vertically opposed to each other. A molding device for multiple bent pipes for manufacturing elbows. (5) A molding apparatus according to claim (2), characterized in that the pressing body is fixedly attached to the back of the split mold pieces located on both sides of the lower mold. Continuous pipe forming equipment. (6) A molding apparatus according to claim (2), characterized in that the pressing bodies are removably attached to the back of the split mold pieces located on both sides of the lower mold. Continuous pipe forming equipment.