TW378164B - Method of producing bent pipe without thinning and device therefore - Google Patents

Abstract

The invented method comprises reducing the thickness at the inner circular side of a blank pipe prior to bending to an appropriate value, shifting the thickness reduced to the outer circular side of the blank pipe prior to bending so that the thickness of the outer circular side increases a thickness of the inner circular side. The thickness increased at the outer circular side can be used to compensate the inner circular side in order to achieve a thickness without thinning in thickness after a bending machine bends the pipe. Using the invented method and device of producing a bent pipe without thinning and the propping open principle of a bevel cone (or a cylindrical cylinder) of an inside diameter propping open machine, let a plurality of propping up plates of the propping up machine to change the outside diameter while maintaining the original inside diameter by outwardly and radially propping the inside diameter of the upper half circle of the pipe to the original inside diameter. Then using the circle of a forming mold to change the up-lifting force into an inward directional force, thereby achieving a shifting of the thickness by using the lower half outside diameter bending mold and the outside jacket returned to said portion inside the pipe to press .

Description

Printed by the Central Bureau of Standards of the Ministry of Economic Affairs and Industrial Cooperatives A7 B7 " " 1 · 1 ··-V. Description of the invention (1) [Detailed description of the invention] [Technical field to which the invention belongs] The present invention relates to the manufacture of bent pipes The method and device, in particular, provide a thin tube that can be reduced and its manufacturing method and device. [Knowledge technology] In order to understand the cause of the formation of elbows, we need to further explain the relevant metallurgical names, such as: "Down strength" is when the metal is subjected to a force, and the force exceeds a force point, the metal begins to produce It is said to be caused by permanent deformation or bending such as stretching or compression. Conversely, when the metal is subjected to a bending force and the force does not exceed the "drop strength" described above, its own elasticity will cause the metal to spring back to unbent. The former shape; "tensile strength" means that when the external force is greater than the "dropping strength" of the above metal, after the semi-plastic deformation occurs, if the external force continues to increase to the critical collapse point of the metal, the force point is called, and When the external force exceeds the above-mentioned "tensile strength", it will cause the metal to rupture and tear. It can be known from the above that when a metal is subjected to a force greater than the "falling strength" and less than the "tensile strength", its metal properties will produce a semi-plastic state, but due to the different metal or alloy its metal properties will cause different half-plasticity. Plasticity, so this semi-plastic property can make the metal extend or compress to a limited extent, especially for curved pipes, for example, it can cause the outer arc side to extend after bending, and the inner arc side will cause compression. The bending force between the above-mentioned drop point and tensile strength must be used to make the bent pipe permanent bending. The paper size is applicable to Chinese National Standard (CNS) A4 specification (210X 297 mm) -4-(Please read first Note on the back then fill out this page}

, 1T printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs A 7 B7 V. Description of Invention (2). Therefore, the elbow must be formed between the "drop strength" and the "tensile strength". When a plain tube is bent, its cross section will have a non-uniform thickness. This phenomenon is called " thickness shift. &Quot; As shown in Fig. 1 (a), when the pipe is bent, the thickness of the pipe wall on the outer arc a side of the curved portion indicated by its section line A-A is displaced toward the inner arc i side by the extension force. Thinning, because the i-side of the inner arc is subjected to a compressive force, the thickness of the pipe wall on the inner arc 1 side will increase due to the displacement of the wall thickness on the outer arc a side, but the thickness of the center line 0 will remain unchanged. change. And the above-mentioned center line 0, the outer arc a side and the inner arc i side will form different outer arcs due to different bending radius distances from each other, and the center line ◦ different elongation and compression rate from the inner arc i side will also be different. Different thicknesses are formed between the parts of the bend. Generally, the name of the unit for bending a pipe bend is based on the diameter of the pipe as the bending radius D. For example, 1 X D is the center bending radius equal to the diameter of the pipe, and 2 X D is the center bending radius forming twice the diameter of the pipe. In other different bending radii as shown in Fig. 2, the elongation on the outer arc a side and the compression ratio on the inner arc i side increase or decrease with the bending radius. In the bending radius of 1.5XD and the bending radius of 3XD in Figure 1 (a), the outer arc a / side elongation and inner arc 1 > side compression ratio of 1.5XD bending radius are all 3 3%. However, the elongation of the outer arc a 外 side and the inner arc i 〃 side of the bending radius of 3 XD are only 16%. As mentioned above, since the extension of the outer arc a /, a 〃 side is equal to the reduction of the thickness of the elbow, the thickness reduced from the outer arc a >, a 〃 side after the above-mentioned curved pipe is transferred to the inner arc i > This paper music scale applies Chinese National Standard (CNS) A4 specification (2 丨 0X297mm> -5-(谙 Please read the precautions on the back before filling this page)

* 1T 1. Printed by the Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (3) The principle on the side of i can be seen that 'the thinning rate on the a side of the outer arc is equal to the increase on the i side of the inner arc Thickness rate, and elongation rate and thinning rate can also be obtained by the same calculation formula, so the thinning rate of pipe fittings can be calculated by the same formula. However, the formula will vary depending on the type of pipe material, the thickness of the pipe, and the bending radius. However, the results obtained by this formula are quite close to the thickness measured in each part after actual bending, so it can still be effectively applied to Among the various technologies of pipe bending. In addition, the reduction of the thickness of the pipe may also be changed due to the use of different pipe bending auxiliary tools with different functions, such as using an anti-crease mold to prevent wrinkles in the arc of the pipe. The shaft system can prevent the tube from causing elliptical or flat deformation, and the above two auxiliary tools can be used depending on the radius of the bend. Fig. 3 is a diagram showing the boundary between extension and compression when the steel pipe is bent. In the figure, the centerline changes due to extension and compression. An imaginary line between extension and compression is called the neutral axis a. However, this axis will be closer to the i-side of the inner arc, and the elongation of the a-side of the outer arc will extend from the neutral axis 0 a. In addition, the extension of the a-side of the arc will form a reduction in thickness, which will cause the displacement of the pipe thickness to become compressive. After the pipe is bent, the reduced thickness on the side of the outer arc a is transferred to the side of the inner arc i. When the pipe is bent, the metal force near the neutral axis 0 a does not reach its drop strength, but the side of the outer arc a The stress on the side of the inner arc i has exceeded the drop strength, and has formed a permanent extension and compression that cannot restore its original shape. Therefore, when the pipe bending fixture is released, the metal near the neutral axis 0a does not reach its falling point, and the original elasticity of the metal will cause the pipe to return to its original shape slightly. This paper is applicable to China. Standard (CNS) A4 specification (2 丨 〇 X 297 mm) -6-(Please read the notes on the back before filling this page) Order printed by the Consumers Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs Λ7 B7 V. Description of the invention (4 ) Is called Springback (Spnng Back). Therefore, in order to understand and resolve the above problems when bending the pipe, it is necessary to bend it a few times to form overbanding, so as to avoid the phenomenon of insufficient bending angle caused by spring back. In addition, as shown in FIG. 4, it is a rotating drawing method in the commonly used cold bending method. Refer to the drawings to explain the tools and steps used as follows: 1. Fix the plain tube head (not shown) in the bending The mold 1 is clamped between the neck and the clamp 3. 2. Use clamp 3 and bending mold 1 to clamp the end of plain tube. 3. (Depending on the use of the mandrel) Put the mandrel 6 inside the plain tube, and depending on the necessity of the anti-moulding mold 4, put the anti-crease mold 4 between the bending mold 1 and the plain tube. 4. For example, the mobile briquette cylinder 5 is used to press the mobile briquette 2 toward the bending mold 1. 5. When locking the plain tube and the clamp 3, after pressing the mobile pressure block 2 in the direction of the bending mold 1, the axial pressurizing hydraulic cylinder 7 is pressed in the axial direction, and the rotary bending mold 1 is pressed so that It rotates in the clockwise direction to bend and shape the plain tube with the radius of the bending mold 1. Because the above-mentioned critical bending angle is 180 °, although the working efficiency is high and the mass productivity is excellent, there are still disadvantages in that it cannot completely suppress the reduction in the thickness of the outer arc side when the plain tube is bent. [Problems to be Solved by the Invention] The present invention is in view of the above-mentioned various conventional pipe bending technologies. The Chinese National Standard (CNS) A4 specification (210X297 mm 5 ~~~ Γ_ " (Please first Read the note on the back _ Italian matter and fill in this page again) • -15- 、-»Printed by the Central Government Bureau of the Ministry of Economic Affairs and printed by Shellfish Consumer Cooperative Λ7 B7 _ V. Description of the invention (5) The prevention of thinning rate is limited to use Know the rotating pull bending method or different pipe bending methods, and cooperate with various auxiliary tools, such as the above-mentioned mobile pressure block 2, anti-crease mold 4, mandrel 6 and axial pressure hydraulic cylinder 7 etc. The thinning rate of the elbow applies different forces in the axial and radial directions. However, in the past, although different pipe bending methods were used and various auxiliary tools were used, the thinning rate could not be maintained at a level acceptable to the pressure piping. No matter what the bending radius of the bend, the acceptable range for the pressure reduction of pressure pipes for general industrial use is limited to the thickness reduction of the outer arc side tube wall after the plain tube is bent. Within 10% of the wall thickness. From the above, the elongation on the arc side of the elbow is equal to the thinning rate of the wall thickness. The formula for the elongation of the elbow is equal to the thinning rate: (OSR) — (CLR) / (CLR), where , OSR: outer arc radius, CLR: bending radius). For example, taking 4〃 (114. 3mm) 6mm thick steel pipe as an example, the thinning rate must be controlled at S 0.6 mm, and the thinning rate formula is calculated as 4〃 (1 14. 3mm) The thickness of the pipe with a thickness of 6mm and a bending radius R = 1. 5D is an example: the formula is calculated as 8_6 / 6 = 3 3%, even when using the most advanced CNC pipe bending machine and auxiliary tools, Still unable to control its thinning rate below 10%. However, in chemical plants and other piping projects, the above-mentioned bends with a bending radius of R = 1.5 D occupy a considerable proportion. Therefore, the conventional pipe bender is used to reduce the thickness of 1.5D bends. The rate does not match (please read the Vi-I matter on the f side, and then fill out this page) The size of the paper is applicable to the Chinese National Standard (CNS) A4 specification (2 丨 〇X 297 mm) -8- A7 V. Description of the invention (6) Please read the note on the back of the paper-please fill in the notes on this page. Therefore, the current engineering industry still uses pre-manufactured 1.5D elbow joints to replace .5d elbow joints, but the pipe joints must be joined to the plain pipe by welding or other methods, which will increase the cost of building the plant. With the extension of the construction time, how to develop a method that can maintain the thinning rate to zero after bending of the pipe bender is a new technology urgently obtained by the piping engineering community. [Brief description of the drawings] (a) and (b) of FIG. 1 are a schematic cross-sectional view showing the thickness shift of a conventional bent pipe after bending, and an A-A sectional view of the bent pipe, respectively. Fig. 2 is a graph showing that different bending centers have different elongation and compression ratios. Fig. 3 is a diagram illustrating a boundary between extension and compression when the steel pipe is bent. Fig. 4 is an exploded perspective view of a device used in the conventional rotary pull-bending method. (A) and (b) of Fig. 5 are schematic diagrams showing the outer arc side, center line, and inner arc side of the bent tube defining the present invention, and the B-B line cross-sectional view. (A) to (d) of FIG. 6 are diagrams showing respective steps when the thickness shift of the elbow of the present invention is performed. (A) to (c) of Fig. 7 are flowcharts respectively showing when the thickness reduction of the elbow is completed by the manufacturing device capable of reducing the elbow by the present invention. Fig. 8 is a side view of the wedge-shaped spreading piece of the manufacturing apparatus of the present invention and a view showing the completion of the bending of the bent pipe. Figure 9 shows that the original paper size of the original round cross section of the curved pipe restored by the pressure mold is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm). -9- Printed by the Staff Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs __Β7 _ Fifth, the description of the invention (7). [Specific embodiments of the present invention] The manufacturing technology of the bendable pipe of the present invention is aimed at the shortcomings of the above-mentioned bent pipe, and a revolutionary breakthrough has been made for the pressure piping for hundreds of years through a new and innovative theory. The present invention is based on the theory that the outer arc side thinning rate is the inner arc side thickening rate. First, the thickness of the plain tube inner arc side before bending is first reduced, and then the reduced thickness is shifted to On the outer arc side, increase the thickness of the outer arc side by reducing the thickness from the inner arc side in advance, and after forming different thicknesses of the pipe wall on the inner and outer arc sides, when using a pipe bender to bend the pipe, it can be increased from the inner arc side in advance. The above thickness to the outer arc side is restored to the inner arc side due to thickness shift (borrowmg) bending, so that the outer arc side can not reduce its thickness due to bending and can achieve a method of zero thinning of the elbow. According to the above-mentioned elbow-free tube bending method, and referring to FIGS. 5 to 9, the technical principles and methods are described as follows: As shown in FIG. It is defined as 90 °, the center line 0 of the pattern is defined as 0 °, and the i-side of the inner arc is defined as 270. . And for the convenience of explanation, the following description is based on the angle of each line side, and the tube wall thickness of 4mm tube 6mm m plain tube center bending radius 1.5D as an example to explain the technology of the present invention as follows. As shown in (a) to (d) of Figure 6, a tube with a thickness of Φ4 " (114.3mm) and a wall thickness of 6mm is taken as an example. Calculate 8〃 — 6〃 / 6〃 = 0.33 after the above formula. Thinness of 3 3% This paper size applies to Chinese national standard (CNS > Α4 size (210X297mm) _ 1〇_ (Please read the precautions on the back before filling this page)

* 1T Printed by the Shellfish Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs A7 B7 V. Description of the invention (8) ′ and multiplying the thinning rate by the thickness of the pipe (6mmx 3 3% = 1. 9mm) to get 90. The height of the thinning is assumed to decrease the center C of the circle by 1,98 mm to form a new circle R. The intersection of the two outer arcs will form a crescent-shaped area Η ′, which is equal to 90. The area reduced after bending (Fig. 6 (d)), and the thickness shifted (boring) to an area of 270 ° (Fig. 6 (a)), and the crescent area was calculated by computer as 2 2 6mm2 . The technology of the present invention is to shift this area from 270 ° to 90 ° in advance before the plain tube is bent, that is, the area of the crescent shape H = 226mm2 divided by the wall thickness of 6mm to obtain 37.66. mm (virtual height), and this 37.66mm 値 can be regarded as a rectangular area ', and since the thickness shift is along its two sides, dividing 37.66mm by 2 gives 18.83mm (Figure 6 (b) , (C)), according to the above-mentioned theory of thickness shift, a prime tube must be bent 1 · 5D. The outer part of the length of the central arc is pushed down by 18. 83 mm, at which time the prime tube will be pressed down. Two circle centers A > and Hachiman. First, with the center of the circle A < as the reference line, the inner diameter of the semicircle on the tube is radiated from the inside to the outside. When the inner diameter is returned to the original position, the wall area of the semicircular tube will be reduced by 33% , And this thickness has been transferred to the center of the circle A / and A 斜 indicated by the oblique line in FIG. 6 (c), and then directionally from the lower arc circle to the above-mentioned center A from the lower arc circle by the forming die > Focus on pressing back the area between A / and A〃 circle center to complete the thickness shift. Secondly, referring to the drawings, the steps for avoiding thinning elbows of the present invention are described in detail as follows. -、 Insert the inner mold A into the bending point of the plain tube T (Figure 7). —--N-nn LI I t A n-nnn T _ I nn I n *,. /-一 a (Please read the " -Matters on the back before filling this page) This paper standard is in accordance with the Chinese National Standard ( CNS) A4 specification (210X297 mm) -11-Λ 7 Β7 Printed by the Sheller Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs 5. Description of the invention (9) 2. Using upper and outer diameter bending dies (not shown), from 2 7 0. Towards 9 0. Press the pipe down 1 8 · 8mm in the direction, and bend the pipe into a certain shape by the upper inner diameter bending die A and the lower inner diameter bending die B. 3. The above-mentioned bending part is divided by the above-mentioned A-circle center as the upper arc and the lower arc, and then the inner diameter spreader C is used to expand the inner diameter and move to the lower inner diameter bending die B for positioning. Figs. 7 (a) to (c) show the moving inner diameter spreader C, that is, as shown in Figs. 8 (a) and (b), the inner diameter spreader C is inclined to the inclined surface using the principle of the inclined cone. When the cone rod P applies a pulling force, and the inclined cone rod P applies a thrust force to the wedge-shaped spreading piece C p of the inner diameter spreader C, the spreading piece C p is radiated from the inside to the tube by the thrust. The inner diameter of the upper semicircle is propped back to the original inner diameter position, and the pipe of the pressing part is divided into an upper semi-circular arc and a lower semi-circular arc with the center of the A circle as the boundary, and the rear upper arc is 270 ° required to be thinned. The lower part is 90 ° which needs to be thickened. The inner diameter of the upper semicircle is evenly divided into eleven equal parts based on the center of the A circle, and the eleven equal parts respectively form a width equal to the contact area of the inner diameter of the upper semicircle, and these widths form each wedge-shaped opening piece C p, which can be applied axially by the outside of the tube, so that the inner diameter spreader C is forced to support the inner diameter of the tube from the inside to the outside, and the semicircular inner diameter of the tube is returned to the original inner diameter position. Of the radian and require different designs of spread height. Therefore, when designing this special oblique cone with eleven different oblique planes, it is necessary to cooperate with the various oblique plane angles required by the various rising heights of each wedge-shaped spreading sheet, so that the inner diameter of the upper semicircle can be naturally reduced back to 2 The 70 ° outside area makes the fitting elliptical. After the upper semicircle is completed, the part shifted to A / circle center and A〃 circle center can be shifted to 90 ° (please read the precautions on the back before filling this page), νβ This paper size is applicable to China Standard (CNS > A4 size (210X297 mm) Printed by the Central Bureau of Standards, Ministry of Economic Affairs, Industrial and Commercial Cooperatives, A7 B7 5. The area of the invention description (10) can be achieved by the following steps. That is, by the above After each step naturally reduces the outer diameter thickness of the upper semicircle by about 33%, the following steps are performed to centrally press the outer semicircular outer diameter of the tube toward the center A > of which the required 90 ° The thickness of the displacement is shifted to the center of A > and A " by the opening of the plain tube and the inner diameter of the tube, and then the die is bent with a pre-designed outer diameter on the outside of the oval at 270 ° M, as shown in FIG. 9, the mold M is divided into ① lower outer diameter bending mold M 1, ② angle mold M 2, ③ forming mold M 3, ④ center forming auxiliary mold M 4, and ⑤ upper outer diameter bending mold. It is composed of 5 parts such as Μ 5. The above outer diameter bending die M 1 is designed to form an arc on the outside, and the angle die M is 2 is also the same design. When the lower outer diameter bending die M1 is lifted up, the arc will press the angle die M2. The angle die M2 has an angle required to change its forming die M3, so when the angle die M2 The angle of the forming die M3 is forcibly changed when contacting the forming die M3, and the pressure required for forming this tube is when the outer diameter bending die M 1 presses the forming die M 3 and the central forming auxiliary die M 4 by The circular arc is pressed back to the center from the outside to the direction. It can prevent the thickness of the transferred dies from returning to the original position when the lower outer diameter bending die M 1 is directly pressed back. With the forming die M 3, the pressure is gradually pushed back inward from the outside to the inside. 'Using a pre-designed arc between the forming die M 3 and the center forming auxiliary die M 4 which can increase the thickness from 270 ° to 90 °. It can be changed. The thickness is transferred to the outer arc shape of the forming die M 3 and the central forming auxiliary die M 4 'to complete this thickness shifting step. The remaining steps are using traditional bends. The paper size is applicable to the Chinese Standard (CNS) A4 Specifications (210X297 mm) -13 -^ ---: --- „i ------ Order ------ Taste (Please read the idea on the back before filling this page) A7

lli 1 I— nm-1L. | Shi < II-, {Please read the precautions on the back before filling out this page) 5. Description of the invention (11) The machine can bend the tube to complete the outer arc side without reducing its thickness. Can achieve zero thinning method. [Effects of the Invention] The method and device for manufacturing the elbow-free elbow of the present invention, the most significant advantage is that it is not necessary to cut the bending part of each plain tube when piping, and it can avoid the welding caused by welding when welding these elbows. Problems such as blowholes and poor welding. And, because the on-site working environment is mostly unfavorable to welding operations, the technology of the present invention can prefabricate pipelines in the prefabrication factory, which reduces the operation of on-site elbow docking, and can save working time and capital backlog when building a factory. The comparison of the list shows that the present invention can reduce the thinning rate of the curved pipe.

The points are as follows. Printed by the Central Standards Bureau of the Ministry of Economic Affairs of the Consumers Cooperatives -14-This paper size is based on China's D Family Standards (CNS), 8 and 4 threats (21Gx297). 5. Description of the invention (12) Employees of the Central Standards Bureau of the Ministry of Economics Consumption cooperatives can print the content free of thinning elbow _placement__ Traditional elbow piping 1 working faster-slower 2 parts required for work (elbow ...) No need to purchase another 3 each elbow Welding does not have a mouth for every curved part to be connected with a straight pipe. 4 Low manufacturing cost. 5 Short process time. 6 The quality requirements of the staff require less professional skills. Compared with the general staff, the welders do not need more expertise. Same as ordinary workers and welders. 7 Quality stability Bending with the same steel pipe has no problems with different material quality. Elbow, pipe, and electrode materials are different, and the quality is unstable due to different sources. 8 Welding stress requires annealing when necessary. 9 Allowed High pressure and low pressure 10 Low fatigue strength of metal 11 Low cost and low test points No need for multiple test points More cost and more test points Multiple inspections (please read " details of depreciation before filling out this tribute)-· -5 In addition, 'as shown in Figure 1 0 means Φ 4 " The number of welds using the elbow piping method for a telescopic pipe with a thickness of 6 mm is 0, However, the paper size using the traditional piping method is applicable to the Chinese National Standard (CNS) A4 specification (21 × χ 297) -15- 5. Description of the invention (13) The number of welds is 12. And referring to the table above, it can be known that the working time of the zero-thinning elbow pipe and the traditional elbow welded pipe is very different, that is, 'Traditional elbow welded pipe is an example. First, the piping staff must cut the pipe After the ends of the broken and honing pipes are joined with the bevel, they are butted to the elbow. Welding workers must perform welding with a variety of tools and processing methods. The traditional elbow welding pipe has a large number of welds, which will increase the number of Required welding personnel and piping personnel and longer welding and installation time. In contrast to the conventional thin-pipe welded piping, the thinning-free pipe piping of the present invention requires only a pipe-bending staff and a pipe-bending machine, which can greatly reduce the construction time and personnel needs. Table 2 analyzes the man-hours of the zero-thinning-rate elbow piping man-hours of the present invention and the traditional elbow welding piping man-hours by combining their various working hours as follows. The steel pipe is a Φ4〃 Schedule40 A53 steel pipe with a bending radius of R = 1.5 D. It is bent into a telescopic tube shape. The pipe with zero thinning rate in the table is based on one bend as compared to the traditional elbow welded pipe. Taking a mouthful as a unit, the advantages and disadvantages are compared as follows. H---nn —I 1- ..-^ L .-- 1 n In ---- n ding I-::, n ----- I-* '-° Λ- ^ (please first Read the notes on the back and fill in this page) Printed by the Central Standards Bureau of the Ministry of Economic Affairs, Shelley Consumer Cooperatives -16- This paper size is applicable to the Chinese National Standard (CNS) Α4 specification (210 × 297 mm) 5. Description of the invention (4 A7 B7 Printed by the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs

CV1 Crush work time 45 seconds 0.45 X 6 = 2.7 minutes one mouth 6 minutes 6 X 12 = 72 minutes one mouth 10 minutes 10 X 122 = 120 minutes one mouth 40 minutes 40 X 12 = 480 minutes 720 minutes (if necessary, not included Calculation), 0 minutes 0 minutes—mouth 10 minutes 10 X 12 = 120 minutes one mouth 5 minutes 5 X 12 = 60 minutes 854.7 minutes + 60 minutes = 14 hours 14 minutes 7 seconds Traditional elbow welding piping pipe cutting honing pipe end welding Joining the oblique elbow to the straight pipe 1 Welding 1_ Annealing heat treatment of the bending part positioning and clamping of the pipe bender to bend the shape detection (1) RT (2) Visual internal welding slag working hours 0 minutes 0 minutes i0 minutes 0 Minutes 0 minutes run Φ if χ 1 ^ one bend 3 minutes 3 X 6 = 18 minutes one bend 5 minutes 5 X 6 = 30 minutes 30 minutes 108 minutes + 60 minutes = 1 hour 48 minutes zero thinning rate bend pipe piping pipe cutting Honed pipe end welding joint with oblique elbow and straight pipe butt welding annealing annealing heat treatment pipe bending part positioning clamp pipe bender bending forming tube material for different detection 检测 Μ η S 芎 咛 S dish \ y—NH CS 、 ^ ^ TOTAL ΙΊΙ ---: --- ί ^ ------ subscribe -------- l · (Please read the legal and legal matters on the back before filling in this page) This paper size is applicable to the Chinese National Standard (CNS) A4 specification (210X297 mm) V. Description of the invention (15) It is stated that the sign has a mold 4 5 A7 B7 3 6-cylinder pressure type hydraulic block pressure shifting; Type "moving 2 shifter shaft sandwich: arc: curved,: · inner: curved cylinder C; 3 radial pressure; M outer oil mold 〃, upper pressure bending i-mode; increased bending, degree; radial diameter v angle within 5 axes of ii Μ i down,;;; i 2 mode. 7 ·: Μ Μ tube aa device Μ mode ο open 'shape, supporting wire into a mold

aC 4 Μ Outer lower center line is bent into a T-arc double bend center, outer wedge diameter axis

B-sheet opening ° -rm Molding element (please read the back of the article: meaning matters before filling in this page), Thread l · Printed on the paper by the Consumers' Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs, China Paper Standards (CNS) Α4 Specifications (210 × 297 mm) -18-

Claims (1)

Printed by the Consumer Affairs Cooperative of the Central Government Bureau of the Ministry of Economic Affairs A8 B8 C8 D8 6. Scope of patent application 1. A manufacturing method that can reduce the thickness of the elbow, which is characterized by: After pressing down the center, it is divided into the inner diameter of the upper semicircle and the inner diameter of the lower semicircle, and the inner diameter of the upper semicircle is returned to the inner diameter of the circle, so that the thickness of the outer diameter of the inner arc of the curved pipe is reduced in advance. The outer diameter of the lower semicircle is pressed back by the forming die to shift the reduced thickness to the outer diameter of the outer arc of the pipe before bending, and the thickness of the outer arc that is increased by the outer arc is increased after the pipe is bent. Displace the increased thickness of the outer arc on the outer arc to the inner arc to achieve a thickness of zero thinning rate. 2 · The manufacturing method of the elbow-reduced elbow as described in item 1 of the scope of the patent application, wherein the upper semi-circular inner diameter support is provided with a beveled tapered rod toward the wedge-shaped spreader of the inner diameter spreader to apply thrust By using the pushing force of the spreading piece, the spreading piece is radiated from the inside to the outside, and the inner diameter of the upper semicircular tube is returned to the original inner diameter position, so that the outer diameter thickness of the inner arc of the curved pipe is reduced in advance. Thin a proper person. 3. The manufacturing method of the elbow-reduced elbow as described in item 1 of the scope of the patent application, wherein the forming die pressing back is to use a set of outer diameter bending die to transfer the force from the upward direction to the directional from the outside to the inside. The force is applied, and the pressure is concentrated toward the center of the tube to form the radian of the outer diameter of the lower semicircle that is set in advance, and the thickness that is thinned in advance is transferred to the outer diameter of the lower semicircle. 4. A manufacturing device capable of reducing the thickness of an elbow is composed of an outer diameter bending die; an inner diameter spreader; an upper bushing; a lower bushing and a tie rod, etc., which is characterized by the inclined surface of the inner diameter stretcher Cone principle, while applying tension to the beveled cone rod, use the beveled cone rod to open towards the above inner diameter (please read the precautions on the back before filling this page), 1T · Λ This paper size applies to China Standard rate (CNS) A4 specification (210X297 mm) -19-Printed by A8 B8 C8 D8 of the Consumer Cooperatives of the Central Bureau of Standards of the Ministry of Economic Affairs The pushing force causes the above-mentioned spreading sheet to radiate the inner diameter of the upper semicircular tube back to the original inner diameter position from the inside to the outside. The outer diameter bending die is a lower radius bending die; an angle die; a forming die; a center forming auxiliary die; and The upper radius bending die is composed of the same angle outside the lower radius bending die as the angle die to change the angle required for forming the forming die, and after the lower outer diameter bending die presses the forming die and the center forming auxiliary die, Profit Arc under the action of outside to inside concentration for directionally pushed back toward the center of the tube, to achieve a shift by thickness. 5. As described in item 4 of the scope of the patent application, a manufacturing device capable of reducing the elbow, wherein the inner diameter spreader is formed into a cylinder and can be applied to a larger inner diameter of the elbow. (Please read the precautions on the back before filling out this page) * π -L-'1— This paper size applies to China National Standard (CNS) A4 (210X 297 mm) · 20-