JPS5942574B2 - Pressing method - Google Patents

Description

【発明の詳細な説明】 この発明はプレス加工方法によつて金属板に凸部を形成
してなる素材の前記凸部の頂部略中央に凹部を形成する
プレス加工方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a press working method for forming a concave portion approximately at the center of the top of a metal plate in which a convex portion is formed by a press working method.

従来この種のプレス加工方法は、第１図から第３図に示
すように金属板である素材１をダイス４とポンチＴ間で
しわ押え１０とを用い絞り成形により押圧し先づ凸部を
形成する。Conventionally, in this type of press working method, as shown in Figs. 1 to 3, a material 1, which is a metal plate, is pressed by drawing forming between a die 4 and a punch T using a wrinkle presser 10, and a convex portion is first formed. Form.

（第１図）次にダイス４上に前記素材１を裏返して凸部
を上方に載置し、前記凸部の頂部略中央をポンチ７で押
圧しダイス４とポンチＴに沿つた凹部を形成する。（第
２図）さらに前記素材１を裏返して凸部２の内周面３に
ダイス４を当接し、凸部２の外周面６の略中央をポンチ
Ｔによつて押圧して凹部８を形成するものであつた。（
第３図）しかしこの方法では凹部８の周縁の部分９がダ
イス４との摩擦およびポンチＴとの摩擦によつて拘束さ
れ、この部分９に破断が生じるおそれがある。(Fig. 1) Next, the material 1 is placed upside down on the die 4 with the convex portion facing upward, and the approximate center of the top of the convex portion is pressed with the punch 7 to form a concave portion along the die 4 and the punch T. do. (Fig. 2) Further, the material 1 is turned over, a die 4 is brought into contact with the inner circumferential surface 3 of the convex portion 2, and the approximate center of the outer circumferential surface 6 of the convex portion 2 is pressed with a punch T to form a concave portion 8. It was something to do. (
(FIG. 3) However, in this method, the peripheral portion 9 of the recess 8 is restrained by the friction with the die 4 and the punch T, and there is a risk that this portion 9 may break.

この破断を防止するには延性の高い軟材質よりなる金属
板を用い、高性能潤滑剤を用い、あるいはプレスの工程
数を増加するなどの処置が採られていたが、近年省エネ
ルギー対策として高張力鋼板を使用する自動車部品が増
加し、上記のような成形を高張力鋼板を用いて行なう必
要が出て来た。しかし、延性が低く成形性の劣るこの種
の鋼板では上記のような成形において多くの困難が伴な
うのが現状である。この発明はこのような従来の問題点
を解消すべく創案されたもので、延性の低い鋼板よりな
る素材に破断を生じさせることなく容易に凹部を形成し
得るプレス加工方法を提供することを目的とする。To prevent this breakage, measures have been taken such as using metal plates made of highly ductile soft materials, using high-performance lubricants, or increasing the number of pressing steps, but in recent years, as an energy-saving measure, high-tension As the number of automobile parts using steel plates increases, it has become necessary to perform the above-described forming using high-strength steel plates. However, with this type of steel sheet having low ductility and poor formability, there are currently many difficulties involved in the above-mentioned forming. This invention was devised to solve these conventional problems, and its purpose is to provide a press working method that can easily form a recess without causing breakage in a material made of a steel plate with low ductility. shall be.

この発明に係るプレス加工方法は、凹部を形成すべき部
分の周囲を凸部内周面が後退する方向について支持し、
充分なメタルフローを許容し得る状態で、凸部の頂部略
中央を押圧するもので、金属板の板厚をと凹部成形前の
凸部の直径Ｄとの比を／Ｄを１／２００≦を／Ｄ≦１／
２０に設定して、しわの発生を防止するとともに良好な
形状の凹部を形成するものである。The press working method according to the present invention supports the periphery of the portion where the concave portion is to be formed in the direction in which the inner circumferential surface of the convex portion recedes;
It presses approximately the center of the top of the convex part in a state that allows sufficient metal flow, and the ratio of the thickness of the metal plate to the diameter D of the convex part before forming the concave part is 1/200≦ /D≦1/
20 to prevent the occurrence of wrinkles and form concave portions with good shapes.

ここに代表的な高張力鋼板の機械的性質は第１表のとお
りである。以下、高張力鋼板よりなるロードホイールの
デイスクの成形に関する実施例を図面に基づいて説明す
る。従来と同様で第１図に示すように金属板を容器状に
絞り成形した素材１を、ダイスを使用することなく、先
づ第４図に示す素材１の凹部を形成すべき部分の周囲す
なわちフランジ部Ｆを凸部内周面が後退する方向につい
て支持台５で支持し、該支持台５に素材１がなじむこと
なく凸部の頂部略中央をポンチ７で押圧する。The mechanical properties of typical high-strength steel sheets are shown in Table 1. Hereinafter, an example of forming a disk of a road wheel made of high-strength steel plate will be described based on the drawings. As in the conventional case, the material 1 which is formed by drawing a metal plate into a container shape as shown in FIG. The flange part F is supported by a support stand 5 in the direction in which the inner circumferential surface of the convex part recedes, and the approximate center of the top of the convex part is pressed with a punch 7 without the material 1 fitting onto the support stand 5.

次に該素材１を裏返して第５図に示すように前記素材１
の周縁Ｆを支持台５によつて支持しただけの状態で凸部
２の外周面６の頂部略中央をポンチ７によつて押圧して
凹部８を形成する。Next, the material 1 is turned over and the material 1 is turned over as shown in FIG.
While the peripheral edge F of the convex portion 2 is only supported by the support base 5, the approximate center of the top of the outer circumferential surface 6 of the convex portion 2 is pressed by the punch 7 to form the concave portion 8.

このように従来のダイス４を省略すると凹部８の周囲は
内周面３の後退方向についてのみ拘束され、凹部８への
充分なメタルフローが許容されて凹部８の周縁の第３図
に示す部分９に破断が生じるおそれはなくなる。ここに
板厚ｔが凹部８の直径Ｄに比較して薄い場合は凹部８内
の自由変形部に座屈が発生し、板厚ｔが厚すぎると変形
が凸部２の広範囲の部分に伝播して凸部２の形状が悪化
する。If the conventional die 4 is omitted in this way, the periphery of the recess 8 is restricted only in the retreating direction of the inner circumferential surface 3, and sufficient metal flow into the recess 8 is allowed, resulting in a portion of the periphery of the recess 8 shown in FIG. 9 is no longer likely to break. If the plate thickness t is thinner than the diameter D of the concave part 8, buckling will occur in the free deformation part within the concave part 8, and if the plate thickness t is too thick, the deformation will propagate to a wide area of the convex part 2. As a result, the shape of the convex portion 2 deteriorates.

このような問題の発生を防止し得るｔ／Ｄの範囲を実験
的に求めたところ、１／２００≦ｔ／Ｄ≦１／２０とす
るべきであることが判明した。最終的に上型、下型で形
成されたデイスクはその断面形状の一例を第６図に示す
如く、外径側から中心に向つて凸、凹、凸の繰り返しに
なつており、また円周方向に沿つても凹凸形状である。When the range of t/D that can prevent the occurrence of such problems was experimentally determined, it was found that 1/200≦t/D≦1/20. As shown in Figure 6, an example of the cross-sectional shape of the disk finally formed by the upper and lower molds has a convex, concave, and convex pattern that repeats from the outer diameter side toward the center. It also has an uneven shape along the direction.

この形状の成形に際し外径側から凸、凹、凸の形状をそ
れぞれの形状毎に一工程づつ順次本発明法を適用して行
けばよい。また周方向に沿つた凹凸は前記各工程の中へ
それぞれ折込んで行くとよい。この発明法により第１表
に示す機械的性質を持つ６０ｋ９／Ｍｄ級の高張力鋼板
を用い、デイスクを成形したものの板厚分布を第７図に
示す。同形状のデイスクを従来法で同一材料を用い成形
した場合第７図のｊの部分で破断を起し完全なデイスク
は得られなかつた。この発明によると板厚歪の絶対値が
最も大きいところで１０％弱であり、従来のように破断
を起こしやすいＩ，ｊ，ｋ，ｌの範囲で１５〜３０％以
上の板厚歪が発生しており、この発明法は従来法に比べ
てはるかに板厚歪が少なく小さい板厚減少に留まつてい
る。When forming this shape, the method of the present invention may be applied sequentially to convex, concave, and convex shapes from the outer diameter side one step at a time for each shape. Further, it is preferable that the irregularities along the circumferential direction are folded into each of the above steps. FIG. 7 shows the plate thickness distribution of a disc formed using a 60k9/Md grade high-strength steel plate having the mechanical properties shown in Table 1 using the method of the present invention. When a disk of the same shape was molded using the same material using the conventional method, a complete disk could not be obtained because the disk broke at the portion j in FIG. According to this invention, the absolute value of the plate thickness strain is a little less than 10% at the largest point, and unlike the conventional plate thickness strain of 15 to 30% or more occurs in the I, j, k, and l ranges that tend to cause breakage. Compared to the conventional method, the method of the present invention has much less distortion in the sheet thickness and the reduction in the sheet thickness remains small.

さらにこの発明法ではポンチと対向し雌型となるダイス
が不要でポンチカを受ける簡単な支持台があるだけでよ
く金型費用が従来よりも著しく節減される。Furthermore, the method of the present invention does not require a female die facing the punch, and only requires a simple support stand to receive the punch, resulting in a significant reduction in mold cost compared to the conventional method.

前記実施例以外にも種々実験を行つた結果、この発明は
５５〔Ｋ９／ｍ！Ｌ〕〜８０Ｃｋｇ／ｍ！Ｌ〕の引張強
さの高張力鋼に適用し得ることが判明した。As a result of various experiments in addition to the above-mentioned embodiments, the present invention was found to be 55 [K9/m! L]~80Ckg/m! It has been found that the method can be applied to high tensile strength steel with a tensile strength of L].

前述のとおりこの発明に係るプレス加工方法は、凹部を
形成すべき部分の周囲を凸部内周面が後退する方向につ
いて支持し、充分なメタルフローを許容した状態で、凸
部の頂部略中央部を押圧するので、延性の低い鋼板より
なる素材に破断を生じさせることなく容易に凹部を形成
し得る。また１／２００≦ｔ／Ｄ≦１／２０となるよう
にＴ，Ｄを設定しているのでしわの発生を防止し得ると
ともに良好な形状の凹部を形成し得る。As described above, the press working method according to the present invention supports the circumference of the portion where the concave portion is to be formed in the direction in which the inner circumferential surface of the convex portion recedes, and while allowing sufficient metal flow, presses the approximately central portion of the top of the convex portion. Since the material is pressed, the recess can be easily formed without causing breakage in the material made of a steel plate with low ductility. Further, since T and D are set so that 1/200≦t/D≦1/20, it is possible to prevent wrinkles from occurring and to form a well-shaped recess.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図〜第３図は従来法を示す縦断面図：第４図〜第５
図はこの発明法の一実抱例を示す縦断正面図、第６図Ａ
はその後の最終段階のデイスクの斜視図、第６図Ｂは第
６図Ａ（７）Ａ−Ａ断面図、第６図Ｃは第６図ＡＯ）Ｂ
−Ｂ断面図、第７図は同実帷例の従来例のデイスク各部
の板厚減少率ηを示すグラフである。 １・・・・・・素材、２・・・・・・凸部、３・・・・
・・内周面、４・・・・・・ダイス、５・・・・・・支
持台、６・・・・・・外周面、７・・・・・・ポンチ、
８・・・・・・凹部、９・・・・・・部分。Figures 1 to 3 are longitudinal sectional views showing the conventional method; Figures 4 to 5
The figure is a longitudinal sectional front view showing a practical example of this invention method, Fig. 6A
is a perspective view of the disk at the final stage after that, FIG. 6B is a cross-sectional view of FIG. 6A(7)A-A, and FIG. 6C is a sectional view of FIG.
-B sectional view and FIG. 7 are graphs showing the plate thickness reduction rate η of each part of the conventional disk in the same actual example. 1...Material, 2...Protrusion, 3...
...Inner circumferential surface, 4...Dice, 5...Support stand, 6...Outer circumferential surface, 7...Punch,
8... recess, 9... part.

Claims (1)

【特許請求の範囲】 １ プレス加工によつて金属板に凸部を成形加工してな
る素材の前記凸部の頂部略中央に凹部を形成するプレス
加工方法において、金属板の板厚ｔと凹部成形前凸部の
直径Ｄとの比ｔ／Ｄを１／２００≦ｔ／Ｄ≦１／２０ に設定し、ダイスを使用することなく前記凹部を形成す
べき部分の周囲を凸部内周面が後退する方向について支
持し、この状態で凸部の頂部略中央を押圧することを特
徴とするプレス加工方法。[Scope of Claims] 1. In a press working method in which a concave portion is formed approximately in the center of the top of the convex portion of a material obtained by forming a convex portion on a metal plate by press working, the plate thickness t of the metal plate and the concave portion are The ratio t/D to the diameter D of the convex portion before molding is set to 1/200≦t/D≦1/20, and the inner peripheral surface of the convex portion is formed around the area where the concave portion is to be formed without using a die. A press working method characterized by supporting in the retreating direction and pressing approximately the center of the top of the convex part in this state.