WO2014003231A1 - Method for forming curved surface of thick aluminum plate having three-dimensional curvature - Google Patents

Method for forming curved surface of thick aluminum plate having three-dimensional curvature Download PDF

Info

Publication number
WO2014003231A1
WO2014003231A1 PCT/KR2012/006067 KR2012006067W WO2014003231A1 WO 2014003231 A1 WO2014003231 A1 WO 2014003231A1 KR 2012006067 W KR2012006067 W KR 2012006067W WO 2014003231 A1 WO2014003231 A1 WO 2014003231A1
Authority
WO
WIPO (PCT)
Prior art keywords
curvature
aluminum
forming
molding
thick plate
Prior art date
Application number
PCT/KR2012/006067
Other languages
French (fr)
Korean (ko)
Inventor
윤종헌
이정환
Original Assignee
한국기계연구원
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 한국기계연구원 filed Critical 한국기계연구원
Publication of WO2014003231A1 publication Critical patent/WO2014003231A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D35/00—Combined processes according to or processes combined with methods covered by groups B21D1/00 - B21D31/00
    • B21D35/002—Processes combined with methods covered by groups B21D1/00 - B21D31/00
    • B21D35/005—Processes combined with methods covered by groups B21D1/00 - B21D31/00 characterized by the material of the blank or the workpiece
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D11/00—Bending not restricted to forms of material mentioned in only one of groups B21D5/00, B21D7/00, B21D9/00; Bending not provided for in groups B21D5/00 - B21D9/00; Twisting
    • B21D11/10—Bending specially adapted to produce specific articles, e.g. leaf springs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D11/00—Bending not restricted to forms of material mentioned in only one of groups B21D5/00, B21D7/00, B21D9/00; Bending not provided for in groups B21D5/00 - B21D9/00; Twisting
    • B21D11/02—Bending by stretching or pulling over a die
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D11/00—Bending not restricted to forms of material mentioned in only one of groups B21D5/00, B21D7/00, B21D9/00; Bending not provided for in groups B21D5/00 - B21D9/00; Twisting
    • B21D11/20—Bending sheet metal, not otherwise provided for
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
    • B21D22/02—Stamping using rigid devices or tools
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D51/00—Making hollow objects
    • B21D51/02—Making hollow objects characterised by the structure of the objects
    • B21D51/08—Making hollow objects characterised by the structure of the objects ball-shaped objects
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D51/00—Making hollow objects
    • B21D51/16—Making hollow objects characterised by the use of the objects
    • B21D51/18—Making hollow objects characterised by the use of the objects vessels, e.g. tubs, vats, tanks, sinks, or the like

Definitions

  • the present invention relates to a curved surface forming method of an aluminum thick plate having a three-dimensional curvature, and more particularly, to a curved forming method of an aluminum thick plate having a three-dimensional curvature in which the amount of elastic recovery is reduced.
  • Aluminum is a silver-white soft metal, which is made of thin foil or wire because of its malleability and ductility, and its properties vary depending on the purity. It is an electrically conductive material and is a typical light metal in terms of specific gravity. It is often used as a material for wires.
  • aluminum is used as a major material for aircraft, ships and vehicles because of its light and durable characteristics, and easily reacts with oxygen, but after the oxide film is formed, the film is blocked from contact with oxygen, so it does not rust well and is polished. This is often used for parts that need to last long.
  • Aluminum plates are widely used in transport ships that carry liquid gas, such as LNG or LPG, and these liquid gases are liquid gases due to rapid increase in consumption due to high oil prices and reactor accidents.
  • the demand for transport ships for transporting the situation is increasing.
  • a liquid gas carrier is a ship that carries liquid gas from a production base to a receiving base. It is usually called an LNG ship or an LPG ship, or an LG Carrier or an LPG Carrier, depending on the type of liquid gas. Also called).
  • Liquefied natural gas for example, is a gas obtained by liquefying natural gas mainly composed of methane at sub-atmospheric pressure of 162 ° C.
  • the volume ratio of liquid and gas is about 1/600, and the specific gravity of the liquefied state is 0.43 to 0.50.
  • the LNG ship is divided into independent tank type and membrane type according to the shape of the cargo hold, the independent tank type is designed to have a double structure of the tank in which the LENG is stored, and the independent aluminum sphere tank (sphere) It is made to be independent of the hull.
  • Independent tank type has the advantage of accurate analysis of storage tank stability and reliability.
  • Membrane type can take advantage of relatively inexpensive ship and deck space, freely deforms according to the change of tank capacity, and secures the clock. This has the advantage of reducing the cost and the cost of passage of the Suez Canal.
  • the independent tank type storage tank is constructed by welding a plurality of aluminum plate patches formed with a constant curvature to maintain a spherical shape.
  • the welding tank has a perfect shape. Since it becomes difficult to assemble the spherical shape, it is necessary to secure the correct curvature according to the curved molding and to predict the elastic restoration amount of the thick plate due to the spring back.
  • the capacity of the storage tank may be inaccurate and may change the transport capacity of the liquid gas.
  • the disclosure patent relates to the invention relating to the curved surface forming method of a metal plate having a feature of small quantity production of a variety of products to be processed.
  • the spring-back effect of the metal sheet to be formed is analyzed in advance by the application of the carbonaceous large deformation nonlinear finite element analysis method, and then, using a changeable die device composed of a series of forming punches.
  • Disclosed is a method for forming a metal object to be processed into a target shape having a three-dimensional curved surface by hydraulic pressing.
  • the above patent discloses a method for fabricating a metal plate using a variable mold apparatus having a plurality of molding punches to form a target shape having a three-dimensional curved surface, wherein the member dimensions of the metal plate, material properties, and stress-strain relationship data of the material And inputting a machining target surface, calculating a springback effect of the metal plate, and setting the total amount of displacement to be applied to the forming punch point to form the target surface based on this, and a plurality of moldings connected to the hydraulic pressing device based on the data.
  • the invention relates to a molding punch for a variable mold apparatus for forming a metal plate and a variable mold apparatus having the same, it is small in size and easy to install, low installation cost
  • the invention relates to a molding punch for a variable mold apparatus configured using a motor and a screw so that the position control is quick and precise and the reverse rotation prevention function is disclosed.
  • the registered patent includes a drive motor that is supported and fixed inside the casing to provide rotational power; A rotating shaft which is connected to the driving motor and rotates so that a screw thread is formed on an outer circumferential surface thereof; Disclosed is an invention including a brake installed inside the casing and coupled to a braking device for braking the rotating shaft and a punch moving linearly along the thread of the rotating shaft as the rotating shaft rotates.
  • An object of the present invention is to provide a method for forming a curved surface of an aluminum thick plate for reducing the amount of elastic recovery generated during curved forming of an aluminum thick plate.
  • a curved surface forming method of an aluminum thick plate having a three-dimensional curvature includes: a first molding step of forming an aluminum thick plate formed of an aluminum alloy to have a curvature in a direction opposite to a target curvature; And a second molding step of forming the aluminum thick plate to have a target curvature in the same direction as the target curvature. It is configured to include.
  • the first molding step is carried out to have a curvature in the opposite direction to the target curvature, and then the second molding step is carried out to have the target curvature in the same direction as the target curvature. It is made to have an ongoing configuration.
  • the curved surface of the aluminum thick plate is formed to have a curvature in a direction opposite to the target curvature in the first molding step, and then the elastic restoring force is reduced while being molded to have the same curvature in the same direction as the target curvature in the second molding step. You can expect the effect.
  • the first molding step of forming the curvature in a direction different from the target curvature is performed, followed by the second molding step of forming the curvature in the same direction as the target curvature.
  • the effect of improving the precision of the curvature formed on the aluminum plate can be expected, and welding, assembly, joint coupling, etc. for manufacturing a large storage container using the aluminum plate formed to have a three-dimensional curvature.
  • the post-processing can be expected to be easy to effect.
  • FIG. 1 is a perspective view showing a vessel in which a storage container using an aluminum thick plate is formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
  • Figure 2 is a schematic diagram showing the shape of the aluminum plate formed by the curved forming method of the aluminum plate according to an embodiment of the present invention.
  • FIG 3 is a graph showing the stress change of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
  • Figure 4 is a graph of the elastic restoring force of the aluminum plate formed by the curved forming method of the aluminum plate according to an embodiment of the present invention.
  • Figure 5 is a graph of the molding load comparison of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
  • Figure 6 is a block diagram showing a process according to the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
  • FIG. 1 is a perspective view showing a vessel in which a storage container using an aluminum thick plate is formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
  • Liquefied natural gas is a state in which natural gas is liquefied by compressing about 600 times at a temperature of minus 162 ° C. Therefore, the outer wall of the storage container for storing liquefied natural gas is resistant to low temperature brittleness and has excellent corrosion resistance and mechanical properties. I) is mainly used.
  • the aluminum thick plate will be referred to as a metallic plate including a metal plate having a thickness of at least 10 mm of aluminum.
  • the storage container 10 for transporting the liquefied natural gas is formed in the shape of a sphere having a predetermined diameter and having an internal space, and a plurality of vessels are mainly installed in the vessel 1, and the vessel ( The liquid liquefied natural gas is accommodated in the internal space of the storage container 10 installed in 1) and is transported to a desired position by the movement of the vessel 1.
  • the storage container 10 has a diameter of 40m or more on an inner surface thereof to store a large amount of liquid or gaseous storage material in the inner space thereof.
  • a diameter of 40m or more on an inner surface thereof to store a large amount of liquid or gaseous storage material in the inner space thereof.
  • smaller or larger configurations are possible, but larger diameters would be desirable to store large amounts of storage material.
  • the storage container 10 for forming a large internal space is molded by forming a plurality of plates 20 to be curved and then jointed to form a large curved surface.
  • the plate 20 formed of a thick aluminum plate is subjected to curved molding at a warm temperature (about 300 °C to 450 °C) in order to reduce the molding load and the elastic restoring amount generated in the large surface forming.
  • Figure 2 is a schematic diagram showing the shape of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention
  • Figure 3 is an aluminum molded by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
  • Figure 4 is a graph showing the stress change of the thick plate
  • Figure 4 is a comparison graph of the elastic restoring force of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
  • FIG 5 is a comparison graph of the molding load of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention
  • Figure 6 is a block showing a process according to the forming method of the aluminum thick plate according to an embodiment of the present invention. It is also.
  • the thickness of the aluminum plate, the curvature of the mold, the lattice spacing of the mold in order to analyze the elastic restoring force and molding load of the aluminum plate according to the molding conditions and process conditions based on the aluminum plate that is molded to have a target curvature For example, the result of performing the molding analysis by applying the etc. as a variable will be described.
  • the aluminum thick plate is to measure the post-molding dimensions of the thick plate in the x-axis direction.
  • the elastic restoring amount can be measured in a different direction, but since the curved aluminum sheet has the same curvature in both the horizontal, vertical and diagonal directions, the elastic restoring amount is the x-axis direction, which is the longest side of the aluminum thick plate. It would be desirable to measure with.
  • the curved surface forming method of an aluminum thick plate having a three-dimensional curvature may include: a first forming step 40 of forming an aluminum thick plate in which a main material is formed of aluminum to have a curvature in a direction opposite to a target curvature; And a second molding step 50 for molding the aluminum thick plate to have a target curvature in the same direction as the target curvature.
  • the aluminum thick plate is molded into a molded body 30 having a curvature in a direction opposite to a target curvature.
  • the molded body 30 formed through the first molding step 40 is molded to have a target curvature while having the curvature in the same direction as the target curvature by the progress of the second molding step 50.
  • the molded body 30 formed in the first molding step 40 has a target curvature according to the progress of the second molding step 50, the sign of the curvature is rapidly changed so that the molded body ( Since there is a possibility that a problem occurs in the surface quality of 30), by further proceeding the preforming step 60 having the nature of the preliminary process it is possible to solve the surface quality problems of the molded body (30).
  • the molded body 30 formed by the first molding step 40 generates residual stress after elastic restoration. That is, the compressive residual stress is generated on the upper surface of the molded body 30, and the tensile residual stress is generated on the lower surface of the molded body 30.
  • the molded body 30 formed in the first molding step 40 has the curvature in the same direction as the target curvature by the continuous preforming step 60 and the second molding step 50.
  • the residual stress generated in the first molding step 40 cancels the stress distribution generated in the second molding step 50 to reduce the elastic restoring amount.
  • the first graph of Figure 3 is a graph measuring the stress distribution generated in the molded body 30 by the progress of the first molding step 40, the second graph measures the elastic recovery stress generated in the molded body 30 One graph.
  • the third graph is a graph showing the residual stress after the elastic restoring force is applied according to the curved molding of the molded body 30, and with respect to the residual stress in accordance with the progress of the preforming step 60, the molded body 30 ) Is molded to have the same direction as the target curvature, and as shown in the fourth graph, it can be seen that the stress in the direction opposite to the residual stress remaining in the molded body 30 is acting.
  • the residual stress generated in the preforming step 60 and the stress generated by the progress of the second molding step 50 act in different directions. It has the advantage of being partially offset.
  • the molded body 30 is formed by applying the curved forming method of the aluminum thick plate according to the present invention was measured by the elastic restoring amount of 5.2 mm, not applying the curved forming method of the aluminum thick plate according to the present invention. It can be seen that the elastic restoring amount of the case 1 is measured as 7.3 mm.
  • the molded article according to the application of the curved forming method of the aluminum thick plate according to the present invention exhibits a number of experimental results by having an effect of reducing the elastic recovery amount of approximately 29%.
  • a value of x of 560 mm means a position spaced about 560 mm from the central portion of the molded body 30.
  • the molding load is rapidly increased in the first molding step 40, and the molding load according to the progress of the preforming step 60 is rapidly decreased.
  • the molding load according to the progress of the second molding step 50 tends to have a larger molding load than the molding load according to the progress of the preforming step 60.
  • step 50 it can be seen that a molding load of about 250 tons is measured.
  • the molded body is molded to have a curvature in a direction opposite to the target curvature, and then molded to have a target curvature in the same direction as the target curvature.
  • the elastic restoring force generated in the process of forming the molded body to have a target curvature is reduced, and the molding load for forming the molded body is reduced, thereby processing the aluminum plate to have a three-dimensional curvature.
  • This has the advantage of being easier.
  • the post-processing such as joint bonding for producing the molded body, which is an aluminum thick plate having a three-dimensional curvature in a large storage container or the like becomes easy.
  • the curved surface forming method of the aluminum thick plate having the three-dimensional curvature according to the present invention will be highly applicable to not only the aluminum thick plate processing industry, but also various related industries.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)

Abstract

The present invention relates to a method for forming a curved surface of a thick aluminum plate, and more specifically, to a method for forming a curved surface of a thick aluminum plate, which reduces the elastic recovery. The method for forming a curved surface of a thick aluminum plate, according to the present invention, comprises: a first forming step in which a thick aluminum plate, made by bonding a plurality of plates of which the principal material is aluminum, is formed to have a curvature in the opposite direction of the target curvature; a second forming step in which the thick aluminum plate is formed preliminarily to have a curvature smaller than and in the same direction as the target curvature; and a third forming step in which the thick aluminum plate is formed to have the target curvature. The present invention can make it easier to form a curved surface of a thick aluminum plate, thus enabling the manufacturing of formed bodies of various shapes which have curved surfaces, using thick aluminum plates.

Description

삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법Surface forming method of aluminum plate with three-dimensional curvature
본 발명은 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법에 관한 것으로, 상세하게는 탄성 복원량이 감소되는 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법에 관한 것이다. The present invention relates to a curved surface forming method of an aluminum thick plate having a three-dimensional curvature, and more particularly, to a curved forming method of an aluminum thick plate having a three-dimensional curvature in which the amount of elastic recovery is reduced.
알루미늄은 은백색의 부드러운 금속으로 전성과 연성이 커서 얇은 박이나 철사로 제조될 수도 있고, 성질은 순도에 따라 다르며 전기적으로는 양도체이고 비중으로 보면 전형적인 경금속이며, 전성과 연성이 뛰어나고 전기 전도성이 좋아 고압 전선의 재료로 많이 사용된다. Aluminum is a silver-white soft metal, which is made of thin foil or wire because of its malleability and ductility, and its properties vary depending on the purity. It is an electrically conductive material and is a typical light metal in terms of specific gravity. It is often used as a material for wires.
또한, 알루미늄은 가볍고 내구성이 큰 특성을 가지므로 항공기, 선박, 차량의 주요 재료로도 사용되며, 산소와 쉽게 반응하지만 산화 피막이 형성된 후에는 피막에 의해 산소와의 접촉이 차단되어 녹이 잘 슬지 않아 광택이 오래 지속될 필요가 있는 부분에 많이 사용된다. In addition, aluminum is used as a major material for aircraft, ships and vehicles because of its light and durable characteristics, and easily reacts with oxygen, but after the oxide film is formed, the film is blocked from contact with oxygen, so it does not rust well and is polished. This is often used for parts that need to last long.
알루미늄 후판(厚板)은 액화천연가스(LNG) 또는 액화석유가스(LPG) 등 액체가스를 운반하는 운반선박에 많이 사용되고 있으며, 이러한 액체가스는 고유가 및 원자로 사고 등에 따른 소비량이 급증함에 따라 액체가스를 운반하기 위한 운반 선박의 수요가 증가하고 있는 실정이다. Aluminum plates are widely used in transport ships that carry liquid gas, such as LNG or LPG, and these liquid gases are liquid gases due to rapid increase in consumption due to high oil prices and reactor accidents. The demand for transport ships for transporting the situation is increasing.
액체가스 운반선이란 액체가스를 생산기지에서 인수 기지까지 운반하는 선박으로 통상 액체가스의 종류에 따라 엘엔지(LNG)선 또는 엘피지(LPG)선이라 하거나, 엘엔지씨(LNG Carrier) 또는 엘피지씨(LPG Carrier)라 하기도 한다. A liquid gas carrier is a ship that carries liquid gas from a production base to a receiving base. It is usually called an LNG ship or an LPG ship, or an LG Carrier or an LPG Carrier, depending on the type of liquid gas. Also called).
액화천연가스를 예를 들면, 액화천연가스는 메탄이 주성분인 천연가스를 대기압에서 영하 162℃로 액화시킨 가스로서, 액체와 기체의 용적 비율은 약 1/600이고, 액화 상태의 비중은 0.43∼0.50이다. Liquefied natural gas, for example, is a gas obtained by liquefying natural gas mainly composed of methane at sub-atmospheric pressure of 162 ° C. The volume ratio of liquid and gas is about 1/600, and the specific gravity of the liquefied state is 0.43 to 0.50.
그리고, 상기 엘엔지선은 화물창의 형태에 따라 독립탱크형과 멤브레인형으로 구분되며, 독립탱크형은 엘엔지가 보관되는 탱크를 이중 구조의 구형(球形)으로 설계하고, 독립된 알루미늄 구형(球形) 탱크를 선체와 독립되게 만들어지는 형태이다. In addition, the LNG ship is divided into independent tank type and membrane type according to the shape of the cargo hold, the independent tank type is designed to have a double structure of the tank in which the LENG is stored, and the independent aluminum sphere tank (sphere) It is made to be independent of the hull.
독립탱크형은 저장 탱크의 안정성 및 신뢰성에 대한 정확한 분석이 가능한 장점을 가지며, 멤브레인형은 상대적으로 저렴한 선가와 갑판 상부의 공간을 넓게 활용할 수 있고, 탱크 용량 변화에 따른 변형이 자유로우며, 시계 확보가 유리한 점 및 수에즈 운하의 통과 비용이 절감되는 장점을 가진다. Independent tank type has the advantage of accurate analysis of storage tank stability and reliability. Membrane type can take advantage of relatively inexpensive ship and deck space, freely deforms according to the change of tank capacity, and secures the clock. This has the advantage of reducing the cost and the cost of passage of the Suez Canal.
독립탱크형의 저장 탱크는 구(球) 형상을 유지하기 위하여 일정한 곡률로 성형된 다수의 알루미늄 후판 패치를 용접하여 구성되며, 곡면성형된 후판의 곡률이 일정하지 않을 경우, 용접 공정에서 완벽한 형상의 구형을 조립하기 어려워지므로, 곡면성형에 따른 정확한 곡률 확보와 스프링백으로 인한 후판의 탄성 복원량을 예측할 필요성을 가지는 실정이다. The independent tank type storage tank is constructed by welding a plurality of aluminum plate patches formed with a constant curvature to maintain a spherical shape. When the curvature of the curved plate is not constant, the welding tank has a perfect shape. Since it becomes difficult to assemble the spherical shape, it is necessary to secure the correct curvature according to the curved molding and to predict the elastic restoration amount of the thick plate due to the spring back.
이처럼 저장 탱크가 완벽한 형상의 구형으로 형성되지 않는 경우 저장 탱크의 용량이 정확하지 않아 운반하는 액체가스의 운반 용량이 달라지는 상황이 발생할 수 있게 된다. As such, when the storage tank is not formed in a spherical shape, the capacity of the storage tank may be inaccurate and may change the transport capacity of the liquid gas.
한편, 대한민국 공개특허 제2009-0055348호에 따르면, 금속판의 곡면성형방법에 관한 발명이 개시되어 있으며, 상기 공개특허는 가공 대상 제품이 다품종 소량 생산의 특징을 지니는 금속판의 곡면성형 방법에 관한 발명으로, 성형 대상 금속판의 스프링백(Spring-back) 효과를 탄소성 대변형 비선형 유한요소해석 기법의 적용에 의해 사전에 분석한 후, 일련의 성형펀치로 구성된 가변형 금형(Changeable-die) 장치를 이용하여 유압 프레싱함으로써 가공대상 금속판을 3차원 곡면을 가지는 목적 형상으로 성형 가공하는 방법에 관한 발명이 개시된다. On the other hand, according to the Republic of Korea Patent Publication No. 2009-0055348, an invention relating to the curved surface forming method of a metal plate is disclosed, the disclosure patent relates to the invention relating to the curved surface forming method of a metal plate having a feature of small quantity production of a variety of products to be processed. The spring-back effect of the metal sheet to be formed is analyzed in advance by the application of the carbonaceous large deformation nonlinear finite element analysis method, and then, using a changeable die device composed of a series of forming punches. Disclosed is a method for forming a metal object to be processed into a target shape having a three-dimensional curved surface by hydraulic pressing.
상기 공개특허에는 다수의 성형펀치를 구비한 가변형 금형장치를 이용하여 금속판을 가공하여 3차원 곡면을 가지는 목적 형상으로 제작하는 방법에 있어서, 금속판의 부재 치수, 재료 물성치, 재료의 응력-변형율 관계 데이터 및 가공 목표 곡면을 입력하는 단계와, 금속판의 스프링백 효과를 계산하여 이를 토대로 목표곡면을 형성하기 위하여 성형 펀치점에 가할 전체 변위량을 설정하는 단계와, 데이터를 토대로 유압 프레싱장치에 연결된 다수의 성형펀치들이 상,하로 배치되도록 구성되는 가변형 금형장치 내의 성형펀치의 위치를 배열하는 단계와, 상기 상,하 성형펀치 사이에 로딩된 금속판을 프레싱하여 성형 가공하는 단계와, 성형의 정밀도를 확인하기 위해 성형 가공된 상기 금속판의 곡면을 측정하여 목표곡면과 비교하는 단계를 포함하여 이루어지는 구성이 개시된다. The above patent discloses a method for fabricating a metal plate using a variable mold apparatus having a plurality of molding punches to form a target shape having a three-dimensional curved surface, wherein the member dimensions of the metal plate, material properties, and stress-strain relationship data of the material And inputting a machining target surface, calculating a springback effect of the metal plate, and setting the total amount of displacement to be applied to the forming punch point to form the target surface based on this, and a plurality of moldings connected to the hydraulic pressing device based on the data. Arranging the positions of the forming punches in the variable mold apparatus configured to arrange the punches up and down, pressing the metal plate loaded between the upper and lower forming punches, and forming the punches; Measuring the curved surface of the formed metal plate and comparing it with a target curved surface The configuration that the lure is disclosed.
또한, 대한민국 등록특허 제10-1030382호에는, 금속판 성형을 위한 가변형 금형장치용 성형펀치 및 이를 구비한 가변형 금형장치에 관한 발명이 개시되어 있으며, 규모가 작아 설치가 용이하며, 설치 비용이 저렴하고, 위치 제어가 신속하고 정밀하며, 역회전 방지 기능을 갖도록 모터와 스크류를 이용하여 구성한 가변형 금형장치용 성형펀치에 관한 발명이 개시된다. In addition, the Republic of Korea Patent No. 10-1030382, the invention relates to a molding punch for a variable mold apparatus for forming a metal plate and a variable mold apparatus having the same, it is small in size and easy to install, low installation cost The invention relates to a molding punch for a variable mold apparatus configured using a motor and a screw so that the position control is quick and precise and the reverse rotation prevention function is disclosed.
상기 등록특허에는 케이싱 내부에 지지 고정되어 회전 동력을 제공하는 구동모터; 상기 구동모터에 동력 연결되어 회전하는 것으로서 외주면 상에 나사산이 형성되는 회전축; 상기 케이싱 내부에 설치되어 상기 회전축을 제동하기 위한 제동장치 및 상기 회전축에 결합하는 것으로서 상기 회전축이 회전함에 따라 상기 회전축의 나사산을 따라 직선 이동하는 펀치를 포함하여 구성되는 발명이 개시된다. The registered patent includes a drive motor that is supported and fixed inside the casing to provide rotational power; A rotating shaft which is connected to the driving motor and rotates so that a screw thread is formed on an outer circumferential surface thereof; Disclosed is an invention including a brake installed inside the casing and coupled to a braking device for braking the rotating shaft and a punch moving linearly along the thread of the rotating shaft as the rotating shaft rotates.
본 발명의 목적은, 알루미늄 후판의 곡면성형시 발생하는 탄성 복원량을 감소시키기 위한 알루미늄 후판의 곡면성형 방법을 제공하는 것이다. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for forming a curved surface of an aluminum thick plate for reducing the amount of elastic recovery generated during curved forming of an aluminum thick plate.
본 발명에 의한 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법은, 알루미늄 합금으로 형성되는 알루미늄 후판을 목표 곡률과 반대 방향의 곡률을 가지도록 성형하는 제1성형단계; 및 상기 알루미늄 후판을 목표 곡률과 동일 방향으로 목표 곡률을 가지도록 성형하는 제2성형단계; 를 포함하여 구성된다. According to the present invention, a curved surface forming method of an aluminum thick plate having a three-dimensional curvature includes: a first molding step of forming an aluminum thick plate formed of an aluminum alloy to have a curvature in a direction opposite to a target curvature; And a second molding step of forming the aluminum thick plate to have a target curvature in the same direction as the target curvature. It is configured to include.
본 발명에 의한 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법에 의하면, 목표 곡률과 반대 방향의 곡률을 가지도록 제1성형단계가 진행된 다음 목표 곡률과 동일 방향으로 목표 곡률을 가지도록 제2성형단계가 진행되는 구성을 가지도록 이루어진다. According to the curved surface forming method of the aluminum plate having the three-dimensional curvature according to the present invention, the first molding step is carried out to have a curvature in the opposite direction to the target curvature, and then the second molding step is carried out to have the target curvature in the same direction as the target curvature. It is made to have an ongoing configuration.
이처럼, 상기 제1성형단계에서 목표 곡률과 반대 방향의 곡률을 가지도록 알루미늄 후판의 곡면을 성형한 다음 상기 제2성형단계에서 목표 곡률과 동일 방향으로 동일 곡률을 가지도록 성형되면서 탄성 복원력이 감소하는 효과를 기대할 수 있게 된다. As such, the curved surface of the aluminum thick plate is formed to have a curvature in a direction opposite to the target curvature in the first molding step, and then the elastic restoring force is reduced while being molded to have the same curvature in the same direction as the target curvature in the second molding step. You can expect the effect.
이와 같이, 목표 곡률과 다른 방향으로 곡률을 가지도록 성형하는 상기 제1성형단계를 진행한 다음 목표 곡률과 동일 방향으로 동일 곡률을 가지도록 성형하는 상기 제2성형단계가 진행되면서, 알루미늄 후판의 삼차원 곡면형성에 따른 탄성 복원력이 감소하게 되는 효과를 기대할 수 있게 되며, 탄성 복원력이 감소하게 됨에 따라 곡면성형에 따른 알루미늄 후판의 탄성 복원량이 감소하는 효과를 기대할 수 있게 된다. As described above, the first molding step of forming the curvature in a direction different from the target curvature is performed, followed by the second molding step of forming the curvature in the same direction as the target curvature. It can be expected that the effect of reducing the elastic restoring force due to the curved surface formation, and as the elastic restoring force is reduced, it is possible to expect the effect of reducing the elastic restoring amount of the aluminum thick plate according to the curved surface forming.
곡면 성형에 따른 알루미늄 후판의 탄성 복원량이 감소하게 됨으로써, 알루미늄 후판의 곡면 성형이 용이한 효과를 기대할 수 있으며, 용이한 곡면 성형으로 인해 생산성이 향상되는 효과를 기대할 수 있게 된다. By reducing the elastic restoring amount of the aluminum thick plate according to the curved molding, it is possible to expect the easy effect of the curved surface forming of the aluminum thick plate, it is possible to expect the effect of improving the productivity due to the easy curved forming.
탄성 복원량이 감소함에 따라, 알루미늄 후판에 성형되는 곡률의 정밀도가 향상되는 효과를 기대할 수 있으며, 삼차원 곡률을 가지도록 형성되는 알루미늄 후판을 이용하여 대형 저장용기를 제조하기 위한 용접, 조립, 이음 결합 등의 후가공이 용이한 효과를 기대할 수 있게 된다. As the amount of elastic recovery decreases, the effect of improving the precision of the curvature formed on the aluminum plate can be expected, and welding, assembly, joint coupling, etc. for manufacturing a large storage container using the aluminum plate formed to have a three-dimensional curvature. The post-processing can be expected to be easy to effect.
도 1 은 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판을 이용한 저장용기가 사용된 선박을 나타낸 사시도.1 is a perspective view showing a vessel in which a storage container using an aluminum thick plate is formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
도 2 는 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 형태를 나타낸 개략도.Figure 2 is a schematic diagram showing the shape of the aluminum plate formed by the curved forming method of the aluminum plate according to an embodiment of the present invention.
도 3 은 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 응력 변화를 나타낸 그래프.3 is a graph showing the stress change of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
도 4 는 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 탄성 복원력 비교 그래프.Figure 4 is a graph of the elastic restoring force of the aluminum plate formed by the curved forming method of the aluminum plate according to an embodiment of the present invention.
도 5 는 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 성형 하중 비교 그래프.Figure 5 is a graph of the molding load comparison of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
도 6 은 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 따른 공정을 나타낸 블럭도.Figure 6 is a block diagram showing a process according to the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
* 도면의 주요 부호에 대한 설명 *Description of the main symbols in the drawings
1. 선박 10. 저장용기1. Vessel 10. Storage Container
20. 플레이트 30. 성형체20. Plate 30. Molded product
40. 제1성형단계 50. 제2성형단계40. First Molding Step 50. Second Molding Step
60. 예비성형단계60. Preforming Step
이하에서는 본 발명에 의한 알루미늄 후판의 곡면성형 방법에 대하여 실시 예를 들어 첨부되는 도면을 참조하여 액화천연가스를 저장하는 저장용기를 예를 들어 상세히 살펴보기로 한다. Hereinafter, a storage container for storing liquefied natural gas will be described in detail with reference to the accompanying drawings.
다만, 본 발명의 사상은 이하에서 살펴보는 실시 예에 의해 그 실시 가능 상태가 제한된다고는 할 수 없고, 본 발명의 사상을 이해하는 당업자는 동일한 기술적 사상의 범위 내에 포함되는 다른 실시 예를 이용하여 용이하게 제안할 수 있을 것이나, 이 또한 본 발명의 기술적 사상에 포함된다고 할 것이다. However, the spirit of the present invention is not limited to the implementation state by the embodiments described below, and those skilled in the art to understand the spirit of the present invention using other embodiments falling within the scope of the same technical spirit It may be easily proposed, but this will also be included in the technical idea of the present invention.
그리고, 본 명세서 또는 청구 범위에서 사용되는 용어는 설명의 편의를 위하여 선택한 개념으로, 본 발명의 기술적 내용을 파악함에 있어서, 본 발명의 기술적 사상에 부합되는 의미로 적절히 해석되어야 할 것이다. In addition, terms used in the present specification or claims are concepts selected for convenience of description, and in grasping the technical contents of the present invention, they should be appropriately interpreted as meanings corresponding to the technical idea of the present invention.
도 1은 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판을 이용한 저장용기가 사용된 선박을 나타낸 사시도이다. 1 is a perspective view showing a vessel in which a storage container using an aluminum thick plate is formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
액화천연가스는 천연가스를 영하 162℃ 상태에서 약 600배 압축하여 액화시킨 상태의 가스이므로, 액화천연가스를 저장하는 저장용기의 외벽은 저온 취성에 강하며 내부식성 및 기계적 물성이 뛰어난 알루미늄 후판(厚板)이 주로 사용된다. Liquefied natural gas is a state in which natural gas is liquefied by compressing about 600 times at a temperature of minus 162 ° C. Therefore, the outer wall of the storage container for storing liquefied natural gas is resistant to low temperature brittleness and has excellent corrosion resistance and mechanical properties. I) is mainly used.
이하의 설명에서 상기 알루미늄 후판은 판재의 두께가 적어도 10㎜ 이상의 알루미늄을 포함하는 금속성 판재를 알루미늄 후판이라 칭하기로 한다. In the following description, the aluminum thick plate will be referred to as a metallic plate including a metal plate having a thickness of at least 10 mm of aluminum.
알루미늄 후판을 적용한 저장용기(10)의 대곡면성형 시 블록 타입의 금형을 제작하여 성형하는 성형 방법은 현실적으로 어려우므로, 격자 형태의 금형을 사용하여 다수의 곡면 판재를 성형한 다음 이들 곡면 판재를 이어 붙임으로써 상기 저장용기(10)를 성형하게 된다. In the large-surface molding of the storage container 10 to which the aluminum plate is applied, a molding method of manufacturing a block-type mold and molding is difficult. Therefore, a plurality of curved plates are formed by using a lattice-shaped mold and then the curved plates are joined. As a result, the storage container 10 is molded.
즉, 상기 액화천연가스를 운반하기 위한 상기 저장용기(10)는 일정 정도의 지름을 가지면서 내부 공간을 가지는 구(球) 형태로 형성되어 주로 선박(1)에 다수 개가 설치되고, 상기 선박(1)에 설치되는 상기 저장용기(10)의 내부 공간에 액체 상태의 액화천연가스가 수용되면서 상기 선박(1)의 이동에 의해 원하는 위치로 운반하게 된다.That is, the storage container 10 for transporting the liquefied natural gas is formed in the shape of a sphere having a predetermined diameter and having an internal space, and a plurality of vessels are mainly installed in the vessel 1, and the vessel ( The liquid liquefied natural gas is accommodated in the internal space of the storage container 10 installed in 1) and is transported to a desired position by the movement of the vessel 1.
상기 저장용기(10)는 그 내부 공간에 많은 양의 액체 상태 또는 기체 상태의 저장 물질을 저장하기 위하여 내면의 지름이 40m 이상의 크기로 이루어진다. 물론, 더 작거나 크게 형성되는 구성도 가능하나, 많은 양의 저장 물질을 저장하기 위하여서는 지름이 큰 형태가 바람직할 것이다. The storage container 10 has a diameter of 40m or more on an inner surface thereof to store a large amount of liquid or gaseous storage material in the inner space thereof. Of course, smaller or larger configurations are possible, but larger diameters would be desirable to store large amounts of storage material.
이처럼, 내부 공간을 크게 형성하기 위한 상기 저장용기(10)는 대곡면의 성형을 위하여 다수의 플레이트(20)를 곡면성형한 다음 이음 결합함으로써 그 형태를 성형하게 된다. As such, the storage container 10 for forming a large internal space is molded by forming a plurality of plates 20 to be curved and then jointed to form a large curved surface.
이때, 알루미늄 후판으로 형성되는 상기 플레이트(20)는 대곡면 성형에서 발생하는 성형 하중 및 탄성 복원량을 감소시키기 위하여 온간(약 300℃∼450℃)에서 곡면성형을 진행하게 된다.At this time, the plate 20 formed of a thick aluminum plate is subjected to curved molding at a warm temperature (about 300 ℃ to 450 ℃) in order to reduce the molding load and the elastic restoring amount generated in the large surface forming.
도 2는 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 형태를 나타낸 개략도이고, 도 3은 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 응력 변화를 나타낸 그래프이며, 도 4는 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 탄성 복원력 비교 그래프이다. Figure 2 is a schematic diagram showing the shape of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention, Figure 3 is an aluminum molded by the curved forming method of the aluminum thick plate according to an embodiment of the present invention. Figure 4 is a graph showing the stress change of the thick plate, Figure 4 is a comparison graph of the elastic restoring force of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention.
도 5는 본 발명의 실시 예에 의한 알루미늄 후판의 곡면성형 방법에 의해 성형되는 알루미늄 후판의 성형 하중 비교 그래프이고, 도 6은 본 발명의 실시 예에 의한 알루미늄 후판의 성형 방법에 따른 공정을 나타낸 블럭도이다. 5 is a comparison graph of the molding load of the aluminum thick plate formed by the curved forming method of the aluminum thick plate according to an embodiment of the present invention, Figure 6 is a block showing a process according to the forming method of the aluminum thick plate according to an embodiment of the present invention. It is also.
그리고, 본 발명에서는 알루미늄 후판의 실제 대곡면성형 조건을 위하여 가로와 세로의 길이가 1186×790㎜를 가지면서 20 또는 30㎜ 두께를 가지는 주재료가 알루미늄인 금속성 판재 형태로 이루어지는 구성을 예를 들어 살펴보기로 한다. In the present invention, for the actual large curved surface forming conditions of the aluminum thick plate for example, look at the configuration consisting of a metal plate shape of the main material having a thickness of 20 or 30 mm while having a length of 1186 × 790 mm and a thickness of 20 or 30 mm Shall be.
또한, 목표 곡률을 가지도록 성형되는 상기 알루미늄 후판을 소재로 하여 성형 조건 및 공정 조건에 따른 알루미늄 후판의 탄성 복원력과 성형 하중 등을 분석하기 위하여 상기 알루미늄 후판의 두께, 금형의 곡률, 금형의 격자 간격 등을 변수로 적용하여 성형 해석을 수행한 결과를 예를 들어 살펴보기로 한다. In addition, the thickness of the aluminum plate, the curvature of the mold, the lattice spacing of the mold in order to analyze the elastic restoring force and molding load of the aluminum plate according to the molding conditions and process conditions based on the aluminum plate that is molded to have a target curvature For example, the result of performing the molding analysis by applying the etc. as a variable will be described.
이하의 설명에서는 성형 조건들의 비교 분석을 위하여 성형 조건들을 서로 달리하면서 다수의 실험을 통해 본 발명의 구성을 살펴보기로 한다. 이때 사용되는 실시 예1의 성형조건은 아래 표와 같다.In the following description, the configuration of the present invention will be described through a number of experiments while varying the molding conditions for comparative analysis of the molding conditions. The molding conditions of Example 1 used at this time are shown in the table below.
표 1
구분 다이곡률(㎜) 펀치곡률(㎜) 플레이트 두께(㎜)
Case 1 1,500 1,530 30
Table 1
division Die curvature (mm) Punch Curvature (mm) Plate thickness (mm)
Case 1 1,500 1,530 30
일정한 다이 곡률(1/1500) 및 알루미늄 후판의 두께(30㎜)에 대하여 성형 펀치의 곡률 차이가 있을 경우 탄성 복원력 차이를 실험하였으며, 이때 곡면 성형된 알루미늄 후판의 탄성 복원량은 펀치를 제거한 다음 복원되는 탄성 복원량을 측정하여 실험한 결과이다. In the case of difference in curvature of the forming punch with respect to the constant die curvature (1/1500) and the thickness of the aluminum thick plate (30 mm), the elastic restoring force was tested.In this case, the elastic restoring amount of the curved aluminum plate was recovered after removing the punch. It is the result of experiment by measuring the amount of elastic restoration.
한편, 다양한 성형 조건에 따른 탄성 복원량을 측정하기 위하여 상기 알루미늄 후판은 x-축 방향으로 후판의 성형 후 치수를 측정하게 된다. 물론, 다른 방향으로 탄성 복원량을 측정할 수 있으며, 다만, 곡면 성형된 상기 알루미늄 후판은 수평, 수직 및 대각선 방향 모두 동일한 곡률을 가지고 있으므로, 탄성 복원량은 상기 알루미늄 후판의 가장 긴 변인 x축 방향으로 측정하는 것이 바람직할 것이다.On the other hand, in order to measure the elastic recovery amount according to various molding conditions, the aluminum thick plate is to measure the post-molding dimensions of the thick plate in the x-axis direction. Of course, the elastic restoring amount can be measured in a different direction, but since the curved aluminum sheet has the same curvature in both the horizontal, vertical and diagonal directions, the elastic restoring amount is the x-axis direction, which is the longest side of the aluminum thick plate. It would be desirable to measure with.
본 발명의 실시 예에 의한 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법은, 주재료가 알루미늄으로 형성되는 알루미늄 후판을 목표 곡률과 반대 방향의 곡률을 가지도록 성형하는 제1성형단계(40)와, 상기 알루미늄 후판을 목표 곡률과 동일 방향으로 목표 곡률을 가지도록 성형하는 제2성형단계(50)를 포함하여 구성된다. According to an exemplary embodiment of the present invention, the curved surface forming method of an aluminum thick plate having a three-dimensional curvature may include: a first forming step 40 of forming an aluminum thick plate in which a main material is formed of aluminum to have a curvature in a direction opposite to a target curvature; And a second molding step 50 for molding the aluminum thick plate to have a target curvature in the same direction as the target curvature.
상기 제1성형단계(40)에서는 상기 알루미늄 후판을 목표 곡률과 반대 방향의 곡률을 가지는 성형체(30)를 성형하게 된다. 상기 제1성형단계(40)를 통해 성형되는 상기 성형체(30)는 상기 제2성형단계(50)의 진행에 의해 목표 곡률과 동일 방향의 곡률을 가지면서 목표 곡률을 가지도록 성형된다. In the first molding step 40, the aluminum thick plate is molded into a molded body 30 having a curvature in a direction opposite to a target curvature. The molded body 30 formed through the first molding step 40 is molded to have a target curvature while having the curvature in the same direction as the target curvature by the progress of the second molding step 50.
이때, 상기 제1성형단계(40)에서 성형되는 상기 성형체(30)를 상기 제2성형단계(50)의 진행에 따라 목표 곡률을 가지도록 성형하게 되면, 곡률의 부호가 급격하게 바뀌어 상기 성형체(30)의 표면 품질에 문제가 발생할 가능성이 있기 때문에 예비 공정의 성격을 가지는 예비성형단계(60)를 더 진행하여 상기 성형체(30)의 표면 품질 문제를 해결할 수 있게 된다. In this case, when the molded body 30 formed in the first molding step 40 has a target curvature according to the progress of the second molding step 50, the sign of the curvature is rapidly changed so that the molded body ( Since there is a possibility that a problem occurs in the surface quality of 30), by further proceeding the preforming step 60 having the nature of the preliminary process it is possible to solve the surface quality problems of the molded body (30).
도 3을 참조하여 보면, 상기 제1성형단계(40)에 의해 성형되는 상기 성형체(30)는 탄성 복원 후에 잔류 응력이 발생하게 된다. 즉, 상기 성형체(30)의 상면은 압축 잔류 응력이 발생하게 되며, 상기 성형체(30)의 하면은 인장 잔류 응력이 발생하게 된다. Referring to FIG. 3, the molded body 30 formed by the first molding step 40 generates residual stress after elastic restoration. That is, the compressive residual stress is generated on the upper surface of the molded body 30, and the tensile residual stress is generated on the lower surface of the molded body 30.
이때, 연속적인 상기 예비성형단계(60)와 상기 제2성형단계(50)의 진행에 의해 상기 제1성형단계(40)에서 성형되는 상기 성형체(30)를 목표 곡률과 동일 방향의 곡률을 가지도록 재 성형하게 되면, 상기 제1성형단계(40)에서 발생하게 되는 잔류 응력이 상기 제2성형단계(50)에서 발생되는 응력 분포를 상쇄시켜 탄성 복원량을 감소시키게 된다. In this case, the molded body 30 formed in the first molding step 40 has the curvature in the same direction as the target curvature by the continuous preforming step 60 and the second molding step 50. When re-molding is performed, the residual stress generated in the first molding step 40 cancels the stress distribution generated in the second molding step 50 to reduce the elastic restoring amount.
도 3의 첫번째 그래프는 상기 제1성형단계(40)의 진행에 의해 상기 성형체(30)에서 발생하는 응력분포를 측정한 그래프이며, 두번째 그래프는 상기 성형체(30)에서 발생하는 탄성 복원 응력을 측정한 그래프이다. The first graph of Figure 3 is a graph measuring the stress distribution generated in the molded body 30 by the progress of the first molding step 40, the second graph measures the elastic recovery stress generated in the molded body 30 One graph.
이를 참조하여 보면, 상기 제1성형단계(40)의 진행에 의해 상기 성형체(30)에는 비교적 큰 응력이 발생함을 알 수 있으며, 이에 대하여 반대 방향으로 탄성 복원력이 발생함을 알 수 있다. Referring to this, it can be seen that a relatively large stress is generated in the molded body 30 by the progress of the first molding step 40, and the elastic restoring force is generated in the opposite direction.
또한, 세번째 그래프는 상기 성형체(30)의 곡면 성형에 따른 탄성 복원력이 작용하고 난 다음의 잔류 응력을 나타낸 그래프이고, 이러한 잔류 응력에 대하여 상기 예비성형단계(60)의 진행에 따라 상기 성형체(30)는 목표 곡률과 동일 방향을 가지도록 성형되면서, 네번째 그래프에서 보는 바와 같이 상기 성형체(30)에 남아 있는 잔류 응력과 반대 방향의 응력이 작용하고 있음을 알 수 있다. In addition, the third graph is a graph showing the residual stress after the elastic restoring force is applied according to the curved molding of the molded body 30, and with respect to the residual stress in accordance with the progress of the preforming step 60, the molded body 30 ) Is molded to have the same direction as the target curvature, and as shown in the fourth graph, it can be seen that the stress in the direction opposite to the residual stress remaining in the molded body 30 is acting.
이와 같이, 상기 제2성형단계(50)를 진행함에 따라 상기 예비성형단계(60)에서 발생하는 잔류 응력과 상기 제2성형단계(50)의 진행에 의해 발생하는 응력은 서로 다른 방향으로 작용하여 일정 부분 상쇄되는 장점을 가지게 된다. As such, as the second molding step 50 proceeds, the residual stress generated in the preforming step 60 and the stress generated by the progress of the second molding step 50 act in different directions. It has the advantage of being partially offset.
상기 제2성형단계(50)의 진행에 따라 발생하는 잔류 응력은 상기 예비성형단계(60)의 진행에 따라 상쇄되면서, 탄성 복원력이 저하됨을 알 수 있다. As the residual stress generated by the progress of the second molding step 50 cancels out as the preliminary molding step 60 proceeds, it can be seen that the elastic restoring force is lowered.
도 4를 참조하여 보면, 본 발명에 의한 알루미늄 후판의 곡면성형 방법을 적용하여 성형되는 상기 성형체(30)는 탄성 복원량이 5.2 ㎜로 측정되었으며, 본 발명에 의한 알루미늄 후판의 곡면성형 방법을 적용하지 않은 케이스1의 탄성 복원량은 7.3㎜로 측정됨을 알 수 있다. Referring to Figure 4, the molded body 30 is formed by applying the curved forming method of the aluminum thick plate according to the present invention was measured by the elastic restoring amount of 5.2 mm, not applying the curved forming method of the aluminum thick plate according to the present invention. It can be seen that the elastic restoring amount of the case 1 is measured as 7.3 mm.
즉, 본 발명에 의한 알루미늄 후판의 곡면성형 방법의 적용에 따른 상기 성형체는 대략 29％의 탄성 복원량을 저감시키는 효과를 가지는 것으로 다수의 실험 결과를 나타냄을 알 수 있게 된다. That is, it can be seen that the molded article according to the application of the curved forming method of the aluminum thick plate according to the present invention exhibits a number of experimental results by having an effect of reducing the elastic recovery amount of approximately 29%.
물론, 다수의 실험에 의해 탄성 복원량의 저감 효과는 더욱 넓은 범위에서 측정되었으며, 대략 20 내지 45％ 범위의 저감 효과를 가지는 것으로 다수의 실험 결과에서 도출됨을 알 수 있다. Of course, the reduction effect of the elastic recovery amount was measured in a wider range by a number of experiments, it can be seen that has a reduction effect in the range of approximately 20 to 45% derived from a number of experiment results.
성형 조건 케이스 1에 따른 탄성 복원량은 x=560㎜에서 5.2㎜로 측정된다. x의 값이 560㎜의 의미는 상기 성형체(30)의 중앙 부분으로부터 560㎜ 정도 이격된 위치를 의미한다. The elastic restoring amount according to the molding condition case 1 is measured from x = 560 mm to 5.2 mm. A value of x of 560 mm means a position spaced about 560 mm from the central portion of the molded body 30.
도 5를 참조하여 보면, 상기 제1성형단계(40)에서 성형 하중이 급격히 증가하게 되고, 상기 예비성형단계(60)의 진행에 따른 성형 하중은 급격히 저하되는 경향을 보이게 된다. Referring to FIG. 5, the molding load is rapidly increased in the first molding step 40, and the molding load according to the progress of the preforming step 60 is rapidly decreased.
또한, 상기 제2성형단계(50)의 진행에 따른 성형 하중은 상기 예비성형단계(60)의 진행에 따른 성형 하중보다 더 큰 성형 하중을 가지는 경향을 보이게 된다. In addition, the molding load according to the progress of the second molding step 50 tends to have a larger molding load than the molding load according to the progress of the preforming step 60.
실험 결과적으로 상기 제1성형단계(40)에서는 약 1,130톤의 성형 하중이 발생하는 것으로 측정되었으며, 상기 예비성형단계(60)에서는 약 110톤의 성형 하중이 발생하는 것으로 측정되었고, 상기 제2성형단계(50)에서는 약 250톤의 성형 하중이 발생하는 것으로 측정됨을 알 수 있다. As a result of the experiment, the molding load of about 1,130 tons was measured in the first molding step 40, and the molding load of about 110 tons was measured in the preforming step 60, and the second molding was performed. In step 50 it can be seen that a molding load of about 250 tons is measured.
전술한 바와 같은 본 발명의 설명은 본 발명의 기술적 사상을 예시적으로 설명한 것에 불과한 것으로서, 본 발명이 속하는 기술 분야에서 통상의 지식을 가진자라면 본 발명의 본질적인 특성에서 벗어나지 않는 범위에서 다양한 수정 및 변형이 가능할 것이다. The description of the present invention as described above is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains various modifications without departing from the essential characteristics of the present invention. Modifications may be possible.
본 발명에 의한 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법에 의하면, 상기 성형체를 목표 곡률과 반대 방향으로 곡률을 가지도록 성형한 다음 목표 곡률과 동일 방향으로 목표 곡률을 가지도록 성형하게 된다. According to the curved surface forming method of the aluminum thick plate having a three-dimensional curvature according to the present invention, the molded body is molded to have a curvature in a direction opposite to the target curvature, and then molded to have a target curvature in the same direction as the target curvature.
이에 따라, 상기 성형체를 목표 곡률을 가지도록 성형하는 과정에서 발생하는 탄성 복원력이 저감되는 장점을 가지게 되며, 상기 성형체를 성형하기 위한 성형 하중이 감소되어 알루미늄 후판을 삼차원 곡률을 가지도록 성형하기 위한 가공이 용이해지는 장점을 가지게 된다. Accordingly, the elastic restoring force generated in the process of forming the molded body to have a target curvature is reduced, and the molding load for forming the molded body is reduced, thereby processing the aluminum plate to have a three-dimensional curvature. This has the advantage of being easier.
또한, 삼차원 곡률을 가지는 알루미늄 후판인 상기 성형체를 대형 저장용기 등으로 제조하기 위한 이음 결합 등의 후 가공이 용이해지는 장점을 가지게 된다. In addition, it has the advantage that the post-processing, such as joint bonding for producing the molded body, which is an aluminum thick plate having a three-dimensional curvature in a large storage container or the like becomes easy.
이러한 다양한 장점 및 효과로 인해 본 발명에 의한 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법은 알루미늄 후판 가공 산업뿐만 아니라, 이와 관련된 다양한 산업에 그 이용 가능성이 크다 할 것이다. Due to these various advantages and effects, the curved surface forming method of the aluminum thick plate having the three-dimensional curvature according to the present invention will be highly applicable to not only the aluminum thick plate processing industry, but also various related industries.

Claims (5)

  1. 알루미늄 합금으로 형성되는 알루미늄 후판을 목표 곡률과 반대 방향의 곡률을 가지도록 성형하는 제1성형단계; 및A first molding step of forming an aluminum thick plate formed of an aluminum alloy to have a curvature in a direction opposite to a target curvature; And
    상기 알루미늄 후판을 목표 곡률과 동일 방향으로 목표 곡률을 가지도록 성형하는 제2성형단계; 를 포함하여 구성되는 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법.A second molding step of molding the aluminum thick plate to have a target curvature in the same direction as the target curvature; Surface forming method of aluminum thick plate having a three-dimensional curvature comprising a.
  2. 제 1 항에 있어서,The method of claim 1,
    상기 제1성형단계와 상기 제2성형단계의 사이에는 상기 알루미늄 후판이 목표 곡률과 동일 방향으로 더 작은 곡률을 가지도록 예비 성형하는 예비성형단계가 더 진행되는 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법.Between the first molding step and the second molding step, the aluminum plate having a three-dimensional curvature pre-forming step of preliminarily forming the preform so that the aluminum plate has a smaller curvature in the same direction as the target curvature .
  3. 제 2 항에 있어서,The method of claim 2,
    상기 예비성형단계에서의 성형 하중이 상기 제1,2성형단계에서의 성형하중보다 더 작은 하중을 가지는 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법.And a three-dimensional curvature in which the forming load in the preforming step is smaller than the forming load in the first and second forming steps.
  4. 제 1 항에 있어서,The method of claim 1,
    상기 후판은 적어도 10㎜ 이상의 두께를 가지도록 형성되는 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법.Wherein said thick plate has a three-dimensional curvature formed to have a thickness of at least 10 mm or more.
  5. 제 1 항에 있어서,The method of claim 1,
    상기 제2성형단계 이후에는 목표 곡률을 가지도록 성형된 상기 알루미늄 후판을 이음 결합하여 대형 저장용기를 성형하는 후가공이 더 진행되는 삼차원 곡률을 가지는 알루미늄 후판의 곡면성형 방법.After the second molding step, the aluminum plate having a three-dimensional curvature that is further processed to form a large storage container by jointly joining the aluminum plate formed to have a target curvature further curved surface forming method.
PCT/KR2012/006067 2012-06-25 2012-07-30 Method for forming curved surface of thick aluminum plate having three-dimensional curvature WO2014003231A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR10-2012-0067980 2012-06-25
KR1020120067980A KR101278110B1 (en) 2012-06-25 2012-06-25 Forming method for three dimensional curved surface with aluminium thick plate

Publications (1)

Publication Number Publication Date
WO2014003231A1 true WO2014003231A1 (en) 2014-01-03

Family

ID=48867586

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2012/006067 WO2014003231A1 (en) 2012-06-25 2012-07-30 Method for forming curved surface of thick aluminum plate having three-dimensional curvature

Country Status (2)

Country Link
KR (1) KR101278110B1 (en)
WO (1) WO2014003231A1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101647220B1 (en) * 2014-12-23 2016-08-10 주식회사 포스코 Improved stiffness panel manufacturing mathod
KR20230120445A (en) 2022-02-09 2023-08-17 삼우금속공업 주식회사 Forming method for titanium alloy thick plate with low formability
KR20240078985A (en) 2022-11-28 2024-06-04 삼우금속공업 주식회사 Forming method for titanium alloy large plate
KR20240097527A (en) 2022-12-20 2024-06-27 삼우금속공업 주식회사 Forming method for pure titanium plate

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57195531A (en) * 1981-05-29 1982-12-01 Nippon Steel Corp Formation for thick-walled electric welded tube
JP2005052853A (en) * 2003-07-31 2005-03-03 Tokai Rubber Ind Ltd Method for manufacturing metallic rolled pipe product
JP2006035278A (en) * 2004-07-28 2006-02-09 Yokohama Rubber Co Ltd:The Apparatus for bending metal sheet into circular- arcuate shape
KR20080000880A (en) * 2006-06-28 2008-01-03 정영재 The structure of bending roller machine for 3-dimensional forming

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57195531A (en) * 1981-05-29 1982-12-01 Nippon Steel Corp Formation for thick-walled electric welded tube
JP2005052853A (en) * 2003-07-31 2005-03-03 Tokai Rubber Ind Ltd Method for manufacturing metallic rolled pipe product
JP2006035278A (en) * 2004-07-28 2006-02-09 Yokohama Rubber Co Ltd:The Apparatus for bending metal sheet into circular- arcuate shape
KR20080000880A (en) * 2006-06-28 2008-01-03 정영재 The structure of bending roller machine for 3-dimensional forming

Also Published As

Publication number Publication date
KR101278110B1 (en) 2013-06-24

Similar Documents

Publication Publication Date Title
WO2014003231A1 (en) Method for forming curved surface of thick aluminum plate having three-dimensional curvature
CN101754624B (en) Metal shell body and forming method thereof
KR100904833B1 (en) Battery can
EP2796220B1 (en) Method for designing die for press forming
CN110252882B (en) Aluminum alloy forming method
CN108637081A (en) A kind of method of complex curvatures aluminium alloy element vacuum creep age forming
Welo et al. Flexible 3D stretch bending of aluminium alloy profiles: an experimental and numerical study
Choi et al. Improvement of formability for fabricating thin continuously corrugated structures in sheet metal forming process
CN103639257A (en) Device for performing double curvature sheet bending and forming by utilizing electronic universal testing machine
WO2013119054A1 (en) Apparatus and method for extrusion
KR101339688B1 (en) Forming equipment for making spherical container with aluminium thick plate
WO2013191323A1 (en) Method for molding spherical storage container using aluminum thick plate
CN102814396A (en) Multi-pass necking die and determination method for die-entrance angles of multi-pass necking die
CN209520212U (en) Film-type liquefied natural gas cargo tank maintenance system stainless steel wave card shaping tooling
CN2749596Y (en) Metal pipe straightening die set
CN106844894B (en) Method for measuring and calculating compressive strength of gas storage tank of simple pressure container
CN101762428B (en) Method for testing high-temperature performance of metallic tube
CN102784832B (en) The forming method of a kind of combustion chamber casing
Zhang et al. Study on Multi-step Forming Paths for Double Curved Parts of 1561 Aluminium Alloy
CN115921650A (en) Air pressure superplastic forming method and forming die for titanium alloy thin-wall spherical shell with equal wall thickness
CN110181839A (en) Green lightweight fibreglass-reinforced metal layer pipe and its manufacturing method
CN209568634U (en) Anti-deformation fluorine carbon aluminum veneer
Fang et al. Influences of mandrel types on forming quality of TA18 high strength tube in numerical control bending
He et al. Deformation of revolving closed-shell with multi-curvature profile under inner pressure
CN103008419A (en) Forming device and forming method for pipe with small bending radius

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12880026

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12880026

Country of ref document: EP

Kind code of ref document: A1