JP5630312B2 - Forming limit diagram creation method, crack prediction method and press part manufacturing method in press forming - Google Patents
Forming limit diagram creation method, crack prediction method and press part manufacturing method in press forming Download PDFInfo
- Publication number
- JP5630312B2 JP5630312B2 JP2011030602A JP2011030602A JP5630312B2 JP 5630312 B2 JP5630312 B2 JP 5630312B2 JP 2011030602 A JP2011030602 A JP 2011030602A JP 2011030602 A JP2011030602 A JP 2011030602A JP 5630312 B2 JP5630312 B2 JP 5630312B2
- Authority
- JP
- Japan
- Prior art keywords
- forming
- press
- crack
- fld
- cracks
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims description 50
- 238000010586 diagram Methods 0.000 title claims description 15
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- 239000002184 metal Substances 0.000 claims description 31
- 229910052751 metal Inorganic materials 0.000 claims description 31
- 238000000465 moulding Methods 0.000 claims description 31
- 229910000831 Steel Inorganic materials 0.000 description 50
- 239000010959 steel Substances 0.000 description 50
- 238000005336 cracking Methods 0.000 description 23
- 238000004088 simulation Methods 0.000 description 15
- 238000012360 testing method Methods 0.000 description 14
- 238000005452 bending Methods 0.000 description 12
- 239000000463 material Substances 0.000 description 6
- 230000010354 integration Effects 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000003825 pressing Methods 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 238000000866 electrolytic etching Methods 0.000 description 2
- 238000005461 lubrication Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 241001417523 Plesiopidae Species 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000012778 molding material Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000011218 segmentation Effects 0.000 description 1
- 239000007779 soft material Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Images
Landscapes
- Shaping Metal By Deep-Drawing, Or The Like (AREA)
Description
本発明は、プレス成形における成形限界線図の作成方法、割れ予測方法およびプレス部品の製造方法に関し、具体的には曲げ性に支配される割れを考慮した成形限界線図の作成方法、割れ予測方法およびその方法を用いたプレス部品の製造方法に関するものである。 The present invention relates to a forming limit diagram creation method, crack prediction method, and press part manufacturing method in press molding, and specifically, a forming limit diagram creation method and crack prediction in consideration of cracks controlled by bendability. The present invention relates to a method and a manufacturing method of a pressed part using the method.
プレス成形は、一対の金型の間に金属板を挟んで挟圧し、鋼板等の金属板を型の形状に倣うよう成形して所望の形状の部品を得ようとする代表的な金属加工方法の一つであり、自動車部品、機械部品、建築部材、家電製品等、幅広い製造分野で用いられている。 Press forming is a typical metal processing method in which a metal plate is sandwiched and pressed between a pair of molds, and a metal plate such as a steel plate is formed to follow the shape of the die to obtain a part having a desired shape. It is used in a wide range of manufacturing fields such as automobile parts, machine parts, building components, and home appliances.
プレス成形する際、成形途中で被成形材である金属板に割れが生じる現象がたびたび問題視されており、その解決策として、金属板自体の成形性を高めることの他に、プレス成形における割れを精度よく予測しようとする努力がなされている。例えば、近年よく用いられている方法としては、有限要素法を用いたプレス成形シミュレーションにおいて、金型形状や金属板の機械的特性（材質）の他、金型や金属板の温度、金型を閉塞させる速度（プレス速度）、潤滑条件などの各種プレス条件を変化させて、割れが生じない成形条件を探ろうとする方法がある。 During press molding, the phenomenon that cracks occur in the metal plate, which is the material being molded, is often regarded as a problem. As a solution to this, in addition to improving the formability of the metal plate itself, Efforts are being made to accurately predict this. For example, as a method often used in recent years, in the press molding simulation using the finite element method, in addition to the mold shape and the mechanical characteristics (material) of the metal plate, the temperature of the mold and the metal plate, the mold There is a method in which various pressing conditions such as a closing speed (pressing speed) and lubrication conditions are changed to search for molding conditions that do not cause cracking.
有限要素法は、例えば、特許文献１より抜粋した、図１（ａ）に示すようなハット形部材をプレス成形する場合、図１（ｂ）に示すように、上型１、下型２および金属板３を模擬した部分を、仮想的なメッシュから構成される要素群に分割した上で、プレス成形における各段階で、各要素にどれだけの応力とひずみがどの方向に作用するかを解析（シミュレーション）する方法である。
In the finite element method, for example, when a hat-shaped member as shown in FIG. 1A extracted from
ここで、図１（ｂ）の例では、二次元的（平面的）なメッシュに要素分割しているが、三次元的（立体的）なメッシュに要素分割する場合も多い。また、分割する要素は、図１（ｂ）の上型１、下型２を模擬した部分のように、三角形（三角柱）とする場合もあれば、金属板３を模擬した部分のように、四角形（直方体）とする場合もあり、さらに、図示していないが、六角形（六角柱）とする場合もある。なお、金属板のプレス成形シミュレーションでは、金属板の板厚中心を二次元的なメッシュに要素分割する場合が多い。
Here, in the example of FIG. 1B, the element is divided into a two-dimensional (planar) mesh, but the element is often divided into a three-dimensional (three-dimensional) mesh. In addition, the element to be divided may be a triangle (triangular prism) as in the part simulating the
ところで、従来のプレス割れ発生有無の予測は、有限要素法を用いた金属板のプレス成形シミュレーションで、上記のようなメッシュに分割した各要素の板厚中心における成形後の最大主ひずみε１および最小主ひずみε２（各スカラー）を接点の座標変化から計算により求め、上記最大主ひずみε１および最小主ひずみε２が、別途作成しておいた、図２に示したような成形限界線図ＦＬＤ（Ｆｏｒｍｉｎｇ Ｌｉｍｉｔ Ｄｉａｇｒａｍ）の成形限界線ＦＬＣ（Ｆｏｒｍｉｎｇ Ｌｉｍｉｔ Ｃｕｒｖｅ）を挟んで割れ発生領域、割れなしの領域のいずれの側に存在するかを確認し、割れ発生領域に存在する場合に、割れが発生すると予測していた。 By the way, the conventional prediction of the presence or absence of press cracking is a press forming simulation of a metal plate using the finite element method, and the maximum principal strain ε 1 after forming at the plate thickness center of each element divided into meshes as described above and The minimum principal strain ε 2 (each scalar) is obtained by calculation from the coordinate change of the contact point, and the maximum principal strain ε 1 and the minimum principal strain ε 2 are prepared separately as shown in FIG. Fig. Figure FLD (Forming Limit Diagram) Forming limit line FLC (Forming Limit Curve) is sandwiched between the crack generation area and the non-cracking area to confirm whether it exists in the crack generation area. Was expected to occur.
上記ＦＬＤの作成方法には、代表的なものとして、中島法やＭａｒｃｉｎｉａｋ法がある。これらの方法は、スクライブドサークル等、各種のパターンをマーキングした、形状（幅）の異なる数種のサンプルを使用し、先端曲率半径が２５〜５０ｍｍ程度の球頭パンチ（中島法）あるいは円頭パンチ（Ｍａｒｃｉｎｉａｋ法）を用いて、破断もしくはネッキングが発生するまで張出し成形し、成形後のマーキングの変化から、破断やネッキング発生位置の最大主ひずみ、最小主ひずみを求め、その測定結果を二次元表示して成形限界線（ＦＬＣ）を得る方法である。このＦＬＣは、板厚中心の成形限界を示しており、前述した板厚中心の要素を用いて計算したプレス成形シミュレーションと照らし合わせることで、割れの発生を予測するものである。 Typical methods for creating the FLD include the Nakajima method and the Marciniak method. These methods use several types of samples with various shapes (widths) marked with various patterns, such as scribed circles, ball head punches (Nakajima method) or round heads with a tip radius of curvature of about 25 to 50 mm. Using a punch (Marciniak method), stretch molding until fracture or necking occurs, and determine the maximum and minimum principal strains at the positions where fractures and necking occur from the change in marking after molding. It is a method of displaying and obtaining a forming limit line (FLC). This FLC shows the forming limit at the sheet thickness center, and predicts the occurrence of cracks by comparing with the press forming simulation calculated using the element at the sheet thickness center.
しかしながら、発明者らの研究によれば、上記従来の割れ予測方法を用いた場合、割れ発生なしと予測されたプレス成形条件でも、実際の金属板のプレス成形、特に高強度鋼板の実プレス成形で割れが発生し、予測した結果と現実とが大きく乖離している事例が多々発生していた。 However, according to the research by the inventors, when the above conventional crack prediction method is used, the actual metal plate press forming, particularly the high press strength steel plate press forming, even under the press forming conditions predicted not to generate cracks. In many cases, cracks occurred and the predicted results and the reality were greatly different.
本発明は、従来技術が抱える上記問題点を解決すべく開発したものであり、その目的は、プレス成形における割れの発生を精度よく予測することができる成形限界線図ＦＬＤの作成方法と、そのＦＬＤを用いた割れ予測方法ならびにその予測方法を用いたプレス部品の製造方法を提案することにある。 The present invention was developed to solve the above-mentioned problems of the prior art, and its purpose is to create a forming limit diagram FLD capable of accurately predicting the occurrence of cracks in press molding, and its It is to propose a crack prediction method using FLD and a method for manufacturing a pressed part using the prediction method.
発明者らは、特に高強度鋼板において、従来の方法による割れ発生の予測と実プレス成形における割れ発生の結果とが乖離している原因について鋭意検討を重ねた。その結果、鋼板に発生する割れには、主に低強度、軟質材において起こる延性が支配する割れと、主に高強度、硬質材において起こる曲げ性が支配する割れとがあり、従来の割れ成形限界線図ＦＬＤは、プレス成形における板厚中心の最大主ひずみ、最小主ひずみから成形限界線ＦＬＣを求めていた、すなわち、上記の延性支配の割れに基づいて作成しており、後者の曲げ性支配の割れについては一切考慮していなかったためであることが明らかとなった。 The inventors have made extensive studies on the cause of the difference between the prediction of crack generation by the conventional method and the result of crack generation in actual press forming, particularly in high-strength steel sheets. As a result, cracks that occur in steel sheets mainly include low-strength cracks that are governed by ductility that occurs in soft materials, and high-strength cracks that are governed by bendability that occurs in hard materials. The limit diagram FLD was obtained from the maximum limit strain and minimum limit strain at the center of thickness in press forming, that is, based on the above ductility-controlled cracking. It became clear that it was because no consideration was given to the split of control.
そこで、発明者らは、さらに検討を重ね、プレス成形における板厚中心の最大主ひずみ、最小主ひずみから成形限界線ＦＬＣを得ていた従来の成形限界線図ＦＬＤを改善し、延性が支配する割れに基づく割れ予測に加えて、曲げ性が支配する割れをも考慮した成形限界線図ＦＬＤを用い、併せて、曲げ性支配の割れをも考慮したプレス成形シミュレーションを行うことで、割れの発生を精度良く予測することができることを見出し、本発明を完成させた。 Accordingly, the inventors have further studied and improved the conventional forming limit diagram FLD, which has obtained the forming limit line FLC from the maximum principal strain and the minimum principal strain at the center of the thickness in press forming, and the ductility dominates. In addition to predicting cracks based on cracks, by using a forming limit diagram FLD that also considers cracks controlled by bendability, and by performing press forming simulation that also considers cracks controlled by bendability, cracks are generated. And the present invention has been completed.
すなわち、本発明は、プレス成形する金属板表面に０．５〜１．０ｍｍの標点間距離でマーキングを施した後、その金属板を、先端の最小曲率半径が３〜１０ｍｍのパンチを用いて張出し成形し、パンチ先端部の金属板表面に亀裂が発生した時点における最大主ひずみおよび最小主ひずみをマーキングの変化から測定し、成形限界線を得ることを特徴とするプレス成形における成形限界線図の作成方法である。 That is, the present invention uses a punch having a minimum curvature radius of 3 to 10 mm at the tip thereof after marking the surface of the metal plate to be press-molded with a distance between mark points of 0.5 to 1.0 mm. The forming limit line in press forming is characterized by measuring the maximum principal strain and the minimum principal strain at the time the crack occurs on the surface of the metal plate at the tip of the punch, and obtaining the forming limit line. This is a drawing creation method.
また、本発明は、上記の成形限界線図を基にプレス成形における割れの発生を予測することを特徴とするプレス成形における割れ予測方法を提案する。 In addition, the present invention proposes a crack prediction method in press molding characterized by predicting the occurrence of cracks in press molding based on the above-described forming limit diagram.
また、本発明は、上記のプレス成形における割れ予測方法を用いて金属板の割れ発生の有無を予測し、割れが発生しない条件で金属板をプレス成形することを特徴とするプレス部品の製造方法を提案する。 Further, the present invention predicts the presence or absence of cracks in the metal plate by using the crack prediction method in the above press molding, and press-molds the metal plate under the condition that the crack does not occur. Propose.
本発明によれば、プレス成形における割れの発生有無を精度よく予測することができる成形限界線図ＦＬＤを作成することができるので、自動車のパネル部品、構造・骨格部品等の各種部品をプレス成形する際の割れ発生を精度よく予測することが可能となり、プレス成形を安定して行うことができるとともに、プレス製品の不良率の低減にも大きく寄与することができる。 According to the present invention, it is possible to create a molding limit diagram FLD capable of accurately predicting the occurrence of cracks in press molding, so various parts such as automobile panel parts, structural / frame parts, etc. are press molded. It is possible to accurately predict the occurrence of cracks at the time of pressing, and it is possible to stably perform press molding and to greatly contribute to the reduction of the defective rate of pressed products.
先ず、本発明の基本的技術思想について説明する。
発明者らは、高強度の薄鋼板を対象としたプレス成形の研究を行っていた際、鋼板の引張強さＴＳが９８０ＭＰａ級あるいは１１８０ＭＰａ級と高強度化、硬質化するのに伴い、プレス成形において、くびれ（ネッキング）を起こすことなく破断に至るケースが多く見られることに気付いた。この現象を、図３を用いて説明すると、例えば、球頭パンチを用いて低強度で軟質な鋼板を張出し成形する場合には、一般に、図３（ａ）に示したように局部的にくびれが発生し、そのくびれ部の板厚減少量が大きくなって割れに至るのが普通である。しかし、上述した引張強さが９８０ＭＰａ級や１１８０ＭＰａ級のように高強度化、硬質化した鋼板では、図３（ｂ）に示したように、鋼板表面からクラックが発生して、一気に割れに至ることがあることがわかった。
First, the basic technical idea of the present invention will be described.
When the inventors were conducting research on press forming for high strength thin steel sheets, press forming as the tensile strength TS of the steel sheets increased to 980 MPa class or 1180 MPa class and became harder. , It was noticed that there were many cases that led to fracture without causing necking. This phenomenon will be described with reference to FIG. 3. For example, when a low strength and soft steel sheet is stretched and formed using a ball head punch, generally, as shown in FIG. Usually, the amount of reduction in the thickness of the constricted portion becomes large, and cracks usually occur. However, in the steel sheets with the above-described tensile strengths of 980 MPa class and 1180 MPa class which are increased in strength and hardened, as shown in FIG. I found out that there was something.
そして、上記のような割れ挙動を示す高強度鋼板では、従来のＦＬＤを用いて割れの発生を予測した場合、割れが発生しないと予測されたときでも、プレス成形では割れが発生すること、特に曲げ変形量が大きい部位において多いことがわかった。 And, in the high-strength steel sheet showing the cracking behavior as described above, when the occurrence of cracking is predicted using the conventional FLD, even when it is predicted that no cracking occurs, cracking occurs in the press forming. It was found that the amount of bending deformation was large at the site.
そこで、発明者らは、引張強さＴＳおよび伸びＥｌがほぼ同等で、曲げ性が大きく異なる表１に示す２種類の高強度鋼板ＡおよびＢを、上型と下型からなる金型（モデル金型）を用いて図４に示す自動車のセンターピラー上部でルーフレールと接続する部分を模擬した部品形状にプレス成形し、割れが発生する時の金型の圧下位置（下死点からの距離）を調査し、板厚中心における最大主ひずみおよび最小主ひずみから作成した従来のＦＬＤを用いて予測した割れ発生時の金型圧下位置とを対比し、図５および図６に示した。なお、プレス成形で割れの発生した鋼板位置は、厳しい曲げ加工を受ける部位に相当していた。 Therefore, the inventors have used two types of high-strength steel plates A and B shown in Table 1 having substantially the same tensile strength TS and elongation El and greatly different bendability, as shown in FIG. 4 is pressed into a part shape simulating the part connected to the roof rail at the upper part of the center pillar of the car shown in Fig. 4, and the mold is pressed down (distance from bottom dead center) when cracking occurs. FIG. 5 and FIG. 6 show a comparison with the mold reduction position at the time of crack occurrence predicted using the conventional FLD created from the maximum principal strain and the minimum principal strain at the center of the plate thickness. Note that the position of the steel plate where cracking occurred during press forming corresponded to a portion subjected to severe bending.
図５は、曲げ性に優れる鋼板Ａの結果を示したものであり、従来法で作成したＦＬＤから予測した割れ発生時の金型圧下位置は、プレス成形において割れが発生した金型圧下位置と一致している。しかし、曲げ性に劣る鋼板Ｂの結果を示した図６では、従来法で作成したＦＬＤから予測した割れ発生時の金型圧下位置は、プレス成形において割れが発生した金型圧下位置と大きくずれており、予測精度が悪くなっている。 FIG. 5 shows the result of the steel sheet A having excellent bendability. The mold reduction position at the time of occurrence of cracking predicted from the FLD prepared by the conventional method is the mold reduction position at which cracking occurred in press forming. Match. However, in FIG. 6 showing the result of the steel sheet B having poor bendability, the mold reduction position at the time of crack occurrence predicted from the FLD prepared by the conventional method is greatly different from the mold reduction position at which cracking occurred in press forming. The prediction accuracy is getting worse.
上記の結果から、高強度化、硬質化した高強度鋼板では、プレス成形において曲げ変形を強く受ける部位で起こる割れには、局所的なくびれが発生してこの部分の板厚減少が進展して至る割れ（以降、「延性支配の割れ」とも称する）と、板厚減少を伴わずに鋼板表面に亀裂が発生し、一気に板厚方向に伝播して至る割れ（以降、「曲げ性支配の割れ」とも称する）との２種類の形態があること、そして、後者の曲げ性支配の割れが起こる場合には、従来のＦＬＤを用いた割れ予測方法では、予測精度が大きく悪化することを見出した。 From the above results, in high-strength and hardened high-strength steel plates, local necking occurs in the cracks that occur in parts that are strongly subjected to bending deformation in press forming, and the reduction in the thickness of this part progresses. Cracks that occur (hereinafter also referred to as “ductility-dominated cracks”), cracks that occur on the surface of the steel sheet without reducing the thickness, and propagate in the thickness direction at once (hereinafter referred to as “bendability-controlled cracks”) It was also found that there are two types of forms, and the latter is a case where cracks dominated by the latter occur, and in the conventional crack prediction method using FLD, the prediction accuracy is greatly deteriorated. .
そこで、発明者らは、従来の延性支配に起因した割れの予測方法の問題点を解決し、割れの発生を精度よく予測するには、どうすべきかを検討した。その結果、従来の延性のみを考慮したＦＬＤの他に、さらに、曲げ性を考慮したＦＬＤを作成するとともに、有限要素法を用いたプレス成形シミュレーションで各要素の表面ひずみ（最大主ひずみ、最小主ひずみ）を求め、上記ＦＬＤと上記表面ひずみとを対比して割れを予測してやれば精度よく割れを予測できること、また、上記曲げ性を考慮したＦＬＤを作成するには、先端の曲率半径が小さなパンチを用いて張出し成形し、鋼板表面に亀裂が発生したときの表面ひずみを成形限界として、その時の最大主ひずみ、最小主ひずみを求めてやればよいことを見出した。
本発明は、上記の新規な知見に基づいてなされたものである。
Therefore, the inventors have studied how to solve the problems of the conventional crack prediction method caused by the ductility control and accurately predict the occurrence of cracks. As a result, in addition to the conventional FLD that considers only ductility, an FLD that also considers bendability is created, and the surface strain (maximum principal strain, minimum principal strain) of each element is determined by press forming simulation using the finite element method. If the crack is predicted by comparing the FLD with the surface strain, the crack can be predicted with high accuracy. In addition, in order to create an FLD considering the bendability, a punch with a small radius of curvature at the tip is used. It was found that the maximum principal strain and the minimum principal strain at that time may be obtained by setting the surface strain when a crack occurs on the steel sheet surface as the forming limit.
This invention is made | formed based on said novel knowledge.
以下、本発明について、プレス成形する被成形材（金属板）として鋼板を例にとって具体的に説明する。なお、本発明は、鋼板のみでなく、非鉄金属からなる金属板にも適用できる。
（成形限界線図ＦＬＤの作成方法）
まず、本発明が対象とする鋼板は、板厚が０．６〜３ｍｍで、９０°曲げ（Ｖ曲げ）における限界曲げ半径と板厚の比（限界曲げ半径／板厚）が１．０以上であることが好ましい。板厚が上記範囲外では、プレス成形がなされることが少ないこと、また、限界曲げ半径と板厚の比が１．０未満では、曲げ性が良好であるため、延性支配の割れが起こるため、本発明を用いる必要がないからである。
Hereinafter, the present invention will be described in detail by taking a steel plate as an example of a molding material (metal plate) to be press-formed. In addition, this invention is applicable not only to a steel plate but the metal plate which consists of nonferrous metals.
(Making limit diagram FLD creation method)
First, the steel sheet targeted by the present invention has a plate thickness of 0.6 to 3 mm, and the ratio of the limit bending radius to the plate thickness in 90 ° bending (V bending) (limit bending radius / plate thickness) is 1.0 or more. It is preferable that When the plate thickness is outside the above range, press molding is rarely performed, and when the ratio of the critical bending radius to the plate thickness is less than 1.0, the bendability is good and cracking due to ductility occurs. This is because it is not necessary to use the present invention.
上記鋼板の曲げ性を考慮した成形限界線図ＦＬＤを作成するには、まず、上記鋼板を、図７に示すような幅が１０〜１００ｍｍで種々の幅を有する試験片に加工する。ここで、幅を変えた試験片を種々準備する理由は、ひずみ比（最小主ひずみと最大主ひずみの比）を広範囲に変化させるためである。 In order to create the forming limit diagram FLD considering the bendability of the steel sheet, first, the steel sheet is processed into test pieces having various widths of 10 to 100 mm as shown in FIG. Here, the reason why various test pieces having different widths are prepared is to change the strain ratio (the ratio of the minimum main strain and the maximum main strain) over a wide range.
次いで、その表面に、標点間距離０．５〜１.０ｍｍでマーキングを施す。マーキングの形状（マーキングパターン）は、サークルパターン、ドットパターン、グリッドパターン、同心円パターン等、成形後にひずみ量を計測することができるものであればいずれでもよい。また、マーキング方法は、電解エッチング、フォトエッチング、インクによる転写（スタンプ印刷）等があるが、いずれの方法を用いてもよいが、けがきは、亀裂発生を誘発するため好ましくない。なお、上記標点間距離とは、個々のマーキングパターンの中心間の距離をいう。また、標点間距離０．５〜１.０ｍｍに限定する理由については後述する。 Next, marking is performed on the surface with a distance between the gauge points of 0.5 to 1.0 mm. The marking shape (marking pattern) may be any shape such as a circle pattern, a dot pattern, a grid pattern, or a concentric circle pattern, as long as the strain amount can be measured after molding. The marking method includes electrolytic etching, photoetching, transfer with ink (stamp printing), and any method may be used, but scribing is not preferable because it induces cracking. Note that the distance between the mark points means the distance between the centers of individual marking patterns. The reason for limiting the distance between the gauge points to 0.5 to 1.0 mm will be described later.
次いで、上記試験片を先端の最小曲率半径が３〜１０ｍｍのパンチを用いて張出し成形する。この際、パンチ先端部の試験片（鋼板）表面を、実体顕微鏡や光学顕微鏡、レーザー変位計等で観察しながら成形し、鋼板表面に亀裂が生じた時点で成形を終了する。上記パンチの先端形状は、先端の最小曲率半径が３〜１０ｍｍのものであれば、球頭や楕円球頭、Ｖ字等、どのような形状でもよい。なお、パンチ先端の最小曲率半径を３〜１０ｍｍに限定する理由は、３ｍｍを下回ると、パンチ先端部分の変形領域におけるひずみ変化が大きくなりすぎ、マーキングの標点間距離では主ひずみを正確に測定することが困難になること、一方、１０ｍｍを超えると、後述するように、曲げ変形の影響が弱くなるためである。 Next, the test piece is stretched and formed using a punch having a minimum curvature radius at the tip of 3 to 10 mm. At this time, the surface of the test piece (steel plate) at the tip of the punch is formed while observing with a stereomicroscope, an optical microscope, a laser displacement meter or the like, and the forming is terminated when a crack occurs on the surface of the steel plate. The tip shape of the punch may be any shape such as a spherical head, an elliptical spherical head, or a V shape, as long as the minimum curvature radius of the tip is 3 to 10 mm. The reason for limiting the minimum radius of curvature of the punch tip to 3 to 10 mm is that if it is less than 3 mm, the strain change in the deformation region of the punch tip becomes too large, and the main strain is accurately measured at the distance between marking marks. On the other hand, if it exceeds 10 mm, the influence of bending deformation is weakened as described later.
上記張出し成形終了後、パンチ先端が当接して亀裂が発生した部分のマーキング位置もしくは形状変化を計測して、割れ発生時の最大主ひずみと最小主ひずみを求める。これを、種々の幅の試験片について繰り返して行うことで、亀裂発生時の最大主ひずみおよび最小主ひずみを広範囲に亘って得ることができる。そして、上記のようにして得た最大主ひずみおよび最小主ひずみの測定結果を二次元表示し、成形限界線ＦＬＣを得る。 After completion of the overhang forming, the marking position or shape change of the portion where the crack is generated due to the contact of the punch tip is measured, and the maximum principal strain and the minimum principal strain at the time of occurrence of the crack are obtained. By repeating this for test pieces of various widths, the maximum principal strain and the minimum principal strain at the time of crack generation can be obtained over a wide range. Then, the measurement results of the maximum principal strain and the minimum principal strain obtained as described above are displayed two-dimensionally to obtain a forming limit line FLC.
ここで、標点間距離０．５〜１.０ｍｍに限定する理由について説明する。
前述した表１の鋼板Ｂから、幅が４０ｍｍで、マーキングの標点間距離を０．５〜３．０ｍｍの範囲で種々に変化させた試験片を準備し、上記のようにして、先端の最小曲率半径が１０ｍｍの楕円球頭パンチを用いて張出し成形し、鋼板表面に亀裂が発生した時点の最大主ひずみを測定した。上記測定の結果を、マーキングの標点間距離と、計測された最大主ひずみとの関係として図８に示した。この結果から、マーキングの標点間距離を１.０ｍｍよりも大きくした場合には、最大主ひずみは小さく測定されて、測定精度が低下してしまうことがわかる。一方、標点間距離を０．５ｍｍよりも小さくすると、マーキングすることが難しくなる他、マーキングの標点位置の測定誤差が大きくなるため、主ひずみの測定精度が低下する。よって、本発明においては、標点間距離は０．５〜１.０ｍｍの範囲とする。
Here, the reason why the distance between the gauge points is limited to 0.5 to 1.0 mm will be described.
From the steel plate B of Table 1 described above, a test piece having a width of 40 mm and variously changing the distance between marking marks in the range of 0.5 to 3.0 mm was prepared. The steel sheet was stretched using an elliptical spherical head punch having a minimum curvature radius of 10 mm, and the maximum principal strain when a crack occurred on the steel sheet surface was measured. The result of the measurement is shown in FIG. 8 as the relationship between the distance between the marking marks and the measured maximum principal strain. From this result, it is understood that when the distance between the marking marks is larger than 1.0 mm, the maximum principal strain is measured to be small and the measurement accuracy is lowered. On the other hand, if the distance between the gauge points is smaller than 0.5 mm, it is difficult to perform marking, and the measurement error of the mark position of the marking is increased, so that the measurement accuracy of the main strain is lowered. Therefore, in the present invention, the distance between the gauge points is in the range of 0.5 to 1.0 mm.
次に、パンチ先端の最小曲率半径を１０ｍｍ以下に限定する理由について説明する。図９は、前述した表１の鋼板Ｂから採取した試験片を、パンチ先端の最小曲率半径が１５ｍｍと１０ｍｍの楕円球頭パンチを用いて張出し成形した場合の割れ形態を示す模式図である。パンチ先端の最小曲率半径が１０ｍｍの場合には、図９（ｂ）のように試験片の表面からクラックが発生する曲げ性支配の割れ形態であるが、パンチ先端の最小曲率半径が１５ｍｍのパンチを用いて張り出し成形をした場合には、図９（ａ）のように局所的なくびれの発生から板厚減少が進展して割れに至る延性支配の割れ形態となってしまう。したがって、パンチ先端の最小曲率半径は、曲げ性支配の割れ形態となる１０ｍｍ以下とする。 Next, the reason why the minimum curvature radius at the punch tip is limited to 10 mm or less will be described. FIG. 9 is a schematic view showing a cracking form when a test piece collected from the steel plate B shown in Table 1 is stretched and formed using an elliptical head punch having a minimum curvature radius of 15 mm and 10 mm at the punch tip. When the minimum curvature radius of the punch tip is 10 mm, the crack is controlled by the bending property in which cracks are generated from the surface of the test piece as shown in FIG. 9B, but the punch has a minimum curvature radius of 15 mm. In the case where the bulge-molding is performed using, a ductile-dominated cracking form in which the reduction of the plate thickness progresses from the occurrence of local necking to the cracking as shown in FIG. 9A. Therefore, the minimum radius of curvature of the punch tip is set to 10 mm or less, which is a bending form controlled by cracking.
（割れの予測方法）
本発明のプレス成形における割れの予測方法は、有限要素法等のシェル要素を用いた方法を用いて鋼板を所望の部品形状にプレス成形するシミュレーションを行い、成形後の各要素の鋼板表面の最大主ひずみと最小主ひずみ、あるいは、成形過程における各要素の鋼板表面の最大主ひずみと最小主ひずみの推移を求め、この結果を、別途、前述した方法で作成したＦＬＤ上にプロットし、各要素の最大主ひずみと最小主ひずみのプロットが、ＦＬＤの成形限界線ＦＬＣを挟んで割れ発生領域に存在するかあるいは割れなしの領域に存在するかを確認し、１要素でも割れ発生領域に存在する場合には、その要素の部分で割れが発生すると予測する。なお、上記割れ発生有無の予測は、成形部品全ての要素について行う必要はなく、経験上から、割れの発生が懸念される部位に絞り込み、その部位の要素における鋼板表面の最大主ひずみおよび最小主ひずみを求めて、割れの予測を行ってもよい。
(Prediction method of cracking)
The method for predicting cracks in press forming according to the present invention performs a simulation of press forming a steel plate into a desired part shape using a method using a shell element such as a finite element method, and the maximum of the surface of the steel plate of each element after forming. Obtain the main strain and the minimum main strain, or the transition of the maximum and minimum main strains on the steel sheet surface of each element in the forming process, and plot this result on the FLD created separately by the method described above. Check if the maximum principal strain and minimum principal strain plots are present in the crack generation region or in the region without cracks across the FLD forming limit line FLC, and even one element exists in the crack generation region In that case, it is predicted that a crack will occur in the part of the element. Note that it is not necessary to predict the occurrence of cracks for all the elements of the molded part. From experience, it is narrowed down to the area where cracking is a concern, and the maximum principal strain and minimum principal strain of the steel sheet surface at the element at that part are selected. You may obtain | require distortion and perform prediction of a crack.
上記シミュレーションを行う場合のシェル要素は、薄鋼板の場合、一般に板厚方向の応力は無視できるため、板厚方向に要素を考えないシェル要素を用いることができ、通常、板厚中央位置形状でシミュレーション用モデルを作成することが多い。例えば、図１０に示すように、各要素内に応力やひずみを計算するための点（積分点）を設定し、板厚方向にも板厚等分位置に積分点を設定する。最大主ひずみおよび最小主ひずみは、各積分点において計算するが、本発明における表面ひずみとは、鋼板の表面位置の積分点で計算された最大主ひずみの平均値および最小主ひずみの平均値、図中の記号で説明すると、ｄｓ１〜ｄｓ４の平均値である。なお、上記積分点の数や位置は、シミュレーションに用いる要素の種類によって決まるものである。
In the case of performing the above simulation, in the case of a thin steel plate, the stress in the plate thickness direction is generally negligible. Therefore, a shell element that does not consider the element in the plate thickness direction can be used. A simulation model is often created. For example, as shown in FIG. 10, a point (integration point) for calculating stress and strain is set in each element, and an integration point is set in the plate thickness equal position in the plate thickness direction. The maximum principal strain and the minimum principal strain are calculated at each integration point. The surface strain in the present invention is the average value of the maximum principal strain and the average value of the minimum principal strain calculated at the integration point of the surface position of the steel sheet, to describe the symbol in the figure, the average value of
（プレス部品の製造方法）
本発明のプレス部品の製造方法は、上記に説明した割れ予測方法で、プレス成形における金属板の割れを予測し、もし、割れが発生することが予測された場合には、その条件（金属板、金型）でのプレス成形を止め、割れが発生しない条件に変更してプレス成形することを特徴とするものである。具体的に、プレス成形に用いる金型形状を変更したり、プレス速度や温度、潤滑状態等の成形条件を変更したり、あるいは、金属板の材質（延性、曲げ性等）を変更したりして、割れ発生のない条件にてプレス成形を実施する。
(Pressed parts manufacturing method)
The method for manufacturing a pressed part according to the present invention predicts cracking of a metal plate in press molding by the crack prediction method described above, and if it is predicted that cracking will occur, the condition (metal plate , Mold) is stopped, and press molding is performed by changing the conditions so that cracks do not occur. Specifically, the mold shape used for press molding is changed, the molding conditions such as press speed, temperature and lubrication are changed, or the metal plate material (ductility, bendability, etc.) is changed. Then, press molding is carried out under conditions that do not cause cracks.
前述した表１に示した鋼板Ｂを、図７に示した形状で、最狭部の幅が１０〜１００ｍｍである試験片を数種類作製し、この試験片表面に、電解エッチングでドットパターンを標点間距離１．０ｍｍでマーキングした。
次いで、上記試験片を、図１１に示した、先端の最小曲率半径が２５ｍｍの球頭パンチと、先端の最小曲率半径が７．５ｍｍの楕円球頭パンチを用いて張出し成形した。なお、楕円球頭パンチを用いた張出し成形では、成形中のパンチ先端部の鋼板表面を実体顕微鏡で観察し、表面に亀裂が入った段階で成形を終了した。一方、球頭パンチを用いた張出し成形では、鋼板に貫通割れが発生するまで成形を行った。
次いで、張出し成形後の試験片について、パンチ先端近傍のドット間隔の変化を測定し、最大主ひずみおよび最小主ひずみを求め、ＦＬＤを作成した。なお、上記球頭パンチを用いて作成したＦＬＤは、板厚中心ひずみで成形限界を示す従来のＦＬＤに相当し、楕円球頭パンチを用いて作成したＦＬＤは、曲げ割れを考慮した本発明のＦＬＤに相当する。
Several types of test pieces having the shape shown in FIG. 7 and the width of the narrowest part of 10 to 100 mm are produced from the steel plate B shown in Table 1 described above, and a dot pattern is marked on the surface of the test piece by electrolytic etching. Marking was performed at a point-to-point distance of 1.0 mm.
Next, the test piece was stretched using a spherical head punch with a minimum curvature radius of 25 mm at the tip and an elliptical head punch with a minimum curvature radius of 7.5 mm as shown in FIG. In the overhang forming using an elliptical spherical head punch, the steel plate surface at the tip of the punch being formed was observed with a stereomicroscope, and the forming was completed when the surface was cracked. On the other hand, in the overhang forming using a ball head punch, the forming was performed until a through crack occurred in the steel sheet.
Next, with respect to the test piece after stretch forming, the change in the dot interval in the vicinity of the punch tip was measured, the maximum principal strain and the minimum principal strain were determined, and an FLD was prepared. The FLD produced using the above spherical head punch corresponds to a conventional FLD which shows a forming limit in terms of sheet thickness center strain, and the FLD produced using an elliptical spherical head punch takes into account bending cracks. Corresponds to FLD.
図１２に、上記２種類の方法で作成したＦＬＤをそれぞれ示す。ただし、従来のＦＬＤは鋼板の板厚中心の成形限界であり、本発明のＦＬＤは鋼板の表面の成形限界である。 FIG. 12 shows FLDs created by the above two methods. However, the conventional FLD is the forming limit at the center of the plate thickness of the steel sheet, and the FLD of the present invention is the forming limit of the surface of the steel sheet.
次に、鋼板Ｂを、上型と下型からなる金型（モデル金型）を用いて、図４に示した自動車のセンターピラー上部でルーフレールと接続する部分を模擬した部品形状にプレス成形したところ、上型と下型が完全に密着する下死点から１２ｍｍの位置で割れが発生することを確認した。
Next, the steel plate B was press-formed into a part shape simulating a portion connected to the roof rail at the upper part of the center pillar of the automobile shown in FIG. 4 using a mold (model mold) composed of an upper mold and a lower mold. However, it was confirmed that a crack occurred at a
次いで、上記プレス成形とは別に、鋼板Ｂを上記部分に成形する場合について、有限要素法を用いて３次元プレス成形シミュレーションを行い、金型が下死点に至るまでの成形過程において、割れ発生位置の板厚中心および鋼板表面の最大主ひずみと最小主ひずみの推移を求めた。なお、有限要素法の解析ソフトは、ＬＳ−ＤＹＮＡ Ｖｅｒ９．７１（ＬＳＴＣ；Ｌｉｖｅｒｍｏｒｅ Ｓｏｆｔｗａｒｅ Ｔｅｃｈｎｏｌｏｇｙ Ｃｏｒｐｏｒａｔｉｏｎ社製）を用い、シェル要素は、板厚中心の正方形とし、要素サイズは１．０ｍｍとした。 Next, apart from the above press forming, for the case where the steel plate B is formed in the above part, a three-dimensional press forming simulation is performed using the finite element method, and cracks are generated in the forming process until the die reaches the bottom dead center. The transition of the maximum principal strain and the minimum principal strain on the sheet thickness center at the position and the steel sheet surface was obtained. The analysis software of the finite element method was LS-DYNA Ver9.71 (LSTC; manufactured by Livermore Software Technology), the shell element was a square with a plate thickness center, and the element size was 1.0 mm.
次いで、上記シミュレーションによって求めた割れ発生位置の成形過程における最大主ひずみと最小主ひずみの推移を、図１２に示した従来のＦＬＤと本発明のＦＬＤ上にプロットし、割れが発生する金型位置、すなわち、上記プロットがそれぞれのＦＬＤのＦＬＣ以上の割れ領域に移行する金型の下死点からの位置を求めた結果を、図１３に示す。なお、従来のＦＬＤでは、板厚中心における最大主ひずみ、最小主ひずみで割れ予測を行い、本発明のＦＬＤでは、板表面の最大主ひずみ、最小主ひずみで割れ予測を行った。 Next, the transition of the maximum principal strain and the minimum principal strain in the process of forming the crack occurrence position obtained by the above simulation is plotted on the conventional FLD shown in FIG. 12 and the FLD of the present invention, and the mold position where the crack occurs. That is, FIG. 13 shows the result of obtaining the position from the bottom dead center of the mold where the plot shifts to the cracked area of FLD or more of each FLD. In the conventional FLD, crack prediction was performed using the maximum principal strain and the minimum principal strain at the center of the plate thickness, and in the FLD of the present invention, crack prediction was performed using the maximum principal strain and the minimum principal strain on the plate surface.
図１４に、上記割れ発生の金型位置の予測結果と、プレス成形を行ったときの割れ発生金型位置とを対比して示した。この図によれば、従来のＦＬＤを用いた割れ発生予測では、下死点から７ｍｍの位置まで金型を下降させたときに割れが発生すると予測されたが、本発明のＦＬＤを用いた割れ発生予測では、下死点から１１ｍｍの位置まで金型を下降させたときに割れが発生すると予測されており、プレス成形で実測した割れ発生金型位置（下死点から１２ｍｍの位置）とほぼ一致している。この結果から、本発明のＦＬＤを用いて割れの発生を予測した方が、精度がよいことがわかる。
In FIG. 14, the prediction result of the above-mentioned crack occurrence mold position is compared with the crack occurrence mold position when press molding is performed. According to this figure, in the crack generation prediction using the conventional FLD, it was predicted that the crack would occur when the mold was lowered from the bottom dead center to a position of 7 mm, but the crack using the FLD of the present invention was predicted. In the occurrence prediction, it is predicted that a crack will occur when the mold is lowered to a
本発明は、上記に説明した内容に限られるものではなく、例えば、上記実施例では、引張強さが９８０ＭＰａ級以上の鋼板（１１８０ＭＰａ級の鋼板）に適用した例を示しており、本発明は、このような高強度鋼板のプレス成形に適用することが好ましいが、引張強さが９８０ＭＰａ級未満の鋼板や、鋼板以外の金属板に適用することもできる。 The present invention is not limited to the contents described above. For example, in the above-described embodiment, an example in which the tensile strength is applied to a steel plate having a tensile strength of 980 MPa or higher (a steel plate of 1180 MPa class) is shown. Although it is preferably applied to press forming of such a high-strength steel plate, it can also be applied to a steel plate having a tensile strength of less than 980 MPa class or a metal plate other than the steel plate.
１：プレス金型の上型
２：プレス金型の下型
３：被成形材（金属板、鋼板）
４：メッシュ分割
５：要素
1: Upper mold of press mold 2: Lower mold of press mold 3: Material to be molded (metal plate, steel plate)
4: Mesh division 5: Element
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011030602A JP5630312B2 (en) | 2011-02-16 | 2011-02-16 | Forming limit diagram creation method, crack prediction method and press part manufacturing method in press forming |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011030602A JP5630312B2 (en) | 2011-02-16 | 2011-02-16 | Forming limit diagram creation method, crack prediction method and press part manufacturing method in press forming |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2012166252A JP2012166252A (en) | 2012-09-06 |
| JP5630312B2 true JP5630312B2 (en) | 2014-11-26 |
Family
ID=46970936
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2011030602A Expired - Fee Related JP5630312B2 (en) | 2011-02-16 | 2011-02-16 | Forming limit diagram creation method, crack prediction method and press part manufacturing method in press forming |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5630312B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11609166B2 (en) | 2017-08-23 | 2023-03-21 | Jfe Steel Corporation | Deformation limit evaluation method for sheared surface of metal sheet, crack prediction method, and press die designing method |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6060814B2 (en) * | 2013-05-22 | 2017-01-18 | 新日鐵住金株式会社 | Evaluation method for cracking of thin plate |
| JP6107411B2 (en) * | 2013-05-22 | 2017-04-05 | 新日鐵住金株式会社 | Evaluation method for cracking of thin plate |
| JP5900427B2 (en) * | 2013-07-09 | 2016-04-06 | Ｊｆｅスチール株式会社 | Forming limit measuring method and apparatus |
| JP6325865B2 (en) * | 2014-03-26 | 2018-05-16 | 株式会社Ｊｓｏｌ | Method for determining fracture of parts, system and program, and method for creating theoretical forming limit diagram |
| JP6355980B2 (en) * | 2014-06-13 | 2018-07-11 | ダイハツ工業株式会社 | Strain measuring apparatus and strain measuring method |
| MX2019003652A (en) * | 2016-10-05 | 2019-06-06 | Nippon Steel & Sumitomo Metal Corp | Fracture determination device, fracture determination program, and method thereof. |
| CA3037828A1 (en) * | 2016-10-05 | 2018-04-12 | Nippon Steel & Sumitomo Metal Corporation | Fracture determination device, fracture determination program, and method thereof |
| JP7173246B1 (en) * | 2021-09-01 | 2022-11-16 | Ｊｆｅスチール株式会社 | Press forming limit line acquisition method |
| JP7218783B1 (en) | 2021-09-10 | 2023-02-07 | Ｊｆｅスチール株式会社 | Press forming crack determination method, press forming crack determining device, press forming crack determining program, and press forming crack suppressing method |
| JP7327595B1 (en) | 2022-07-04 | 2023-08-16 | Ｊｆｅスチール株式会社 | METHOD AND DEVICE FOR ACQUIRING FORMING LIMIT OF METAL PLATE |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5212659A (en) * | 1975-07-21 | 1977-01-31 | Rikagaku Kenkyusho | Press forming method |
| MX2009010869A (en) * | 2007-04-12 | 2009-11-26 | Nippon Steel Corp | Breakage prediction method, calculation processing device, program, and recording medium. |
| US8042405B2 (en) * | 2008-07-23 | 2011-10-25 | University Of Kentucky Research Foundation | Method and apparatus for characterizing microscale formability of thin sheet materials |
| JP5294082B2 (en) * | 2009-08-24 | 2013-09-18 | 新日鐵住金株式会社 | Bending limit strain measurement method, bending crack determination method, and bending crack determination program |
-
2011
- 2011-02-16 JP JP2011030602A patent/JP5630312B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11609166B2 (en) | 2017-08-23 | 2023-03-21 | Jfe Steel Corporation | Deformation limit evaluation method for sheared surface of metal sheet, crack prediction method, and press die designing method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2012166252A (en) | 2012-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5630312B2 (en) | Forming limit diagram creation method, crack prediction method and press part manufacturing method in press forming | |
| WO2013157063A1 (en) | Method for drawing forming limit diagram for press forming, crack prediction method, and method for manufacturing pressed components | |
| JP5630311B2 (en) | Method for predicting cracks in press molding and method for manufacturing pressed parts | |
| JP5375941B2 (en) | Press molding tool design method, press molding tool | |
| JP6558515B2 (en) | Method for evaluating deformation limit on sheared surface of metal plate, method for predicting cracks, and method for designing press dies | |
| KR102271009B1 (en) | Evaluation method of deformation limit in shearing surface of metal plate, crack prediction method, and design method of press mold | |
| JP2020040111A (en) | Deformation limit evaluation method, crack prediction method and press metal mold design method | |
| KR20150043476A (en) | Springback amount evaluation method | |
| CN109791098B (en) | Fracture determination device, fracture determination program, and method thereof | |
| WO2013157062A1 (en) | Method for predicting press formation cracks and method for manufacturing pressed product | |
| JP5375942B2 (en) | Metal plate for press forming | |
| JP6107411B2 (en) | Evaluation method for cracking of thin plate | |
| JP6060814B2 (en) | Evaluation method for cracking of thin plate | |
| JP2012011458A (en) | Crack determination method in press forming simulation, and method of manufacturing press formed component using the same | |
| JP2014241129A (en) | Spring-back amount evaluation method | |
| JP2015047605A (en) | Evaluation method and estimation method of bending inside crack |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20130823 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20140529 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20140603 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20140909 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140922 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5630312 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |