{"id":23677,"date":"2025-12-26T19:14:17","date_gmt":"2025-12-27T03:14:17","guid":{"rendered":"https:\/\/shengenfab.com\/?p=23677"},"modified":"2025-12-26T19:50:27","modified_gmt":"2025-12-27T03:50:27","slug":"minimum-flange-length-rules-in-sheet-metal-design","status":"publish","type":"post","link":"https:\/\/shengenfab.com\/ja\/minimum-flange-length-rules-in-sheet-metal-design\/","title":{"rendered":"\u677f\u91d1\u8a2d\u8a08\u306b\u304a\u3051\u308b\u6700\u5c0f\u30d5\u30e9\u30f3\u30b8\u9577\u30eb\u30fc\u30eb"},"content":{"rendered":"
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\n\t\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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\u6a5f\u68b0\u30a8\u30f3\u30b8\u30cb\u30a2\u3084\u88fd\u54c1\u8a2d\u8a08\u8005\u306a\u3089\u8ab0\u3082\u304c\u76f4\u9762\u3059\u308b\u30b7\u30ca\u30ea\u30aa\u3060\u3002\u3042\u306a\u305f\u306fCAD\u3067\u30b3\u30f3\u30d1\u30af\u30c8\u306a\u30b7\u30fc\u30c8\u30e1\u30bf\u30eb\u30fb\u30a8\u30f3\u30af\u30ed\u30fc\u30b8\u30e3\u30fc\u3092\u8a2d\u8a08\u3057\u307e\u3059\u3002\u30e2\u30c7\u30eb\u306f\u6b63\u78ba\u306b\u898b\u3048\u3001\u5e72\u6e09\u691c\u51fa\u306f\u30d1\u30b9\u3057\u3001\u30d5\u30e9\u30c3\u30c8\u30d1\u30bf\u30fc\u30f3\u306f\u30a8\u30e9\u30fc\u306a\u3057\u3067\u751f\u6210\u3055\u308c\u307e\u3059\u3002\u77ed\u7d0d\u671f\u3092\u671f\u5f85\u3057\u3066\u3001DXF\u3092\u5de5\u5834\u306b\u9001\u308a\u307e\u3059\u3002<\/p>

Instead, you receive a “No-Quote” or a request for a design change (ECN). The feedback is simple but frustrating: “The flange on this edge is too short to form.”<\/p>

SolidWorks\u3084Inventor\u306e\u30c7\u30b8\u30bf\u30eb\u306e\u4e16\u754c\u3067\u306f\u3001\u30b7\u30fc\u30c8\u30e1\u30bf\u30eb\u306f\u7121\u9650\u306e\u525b\u6027\u3068\u30bc\u30ed\u306e\u88fd\u9020\u5236\u7d04\u3092\u6301\u3064\u6750\u6599\u3068\u3057\u3066\u6271\u308f\u308c\u307e\u3059\u3002\u3057\u304b\u3057\u3001\u7269\u7406\u7684\u306a\u4e16\u754c\u3067\u306f\u3001\u91d1\u5c5e\u306e\u6210\u5f62\u306f\u6469\u64e6\u3001\u3066\u3053\u3001\u5de5\u5177\u306e\u5f62\u72b6\u306b\u652f\u914d\u3055\u308c\u308b\u6fc0\u3057\u3044\u30d7\u30ed\u30bb\u30b9\u3067\u3059\u3002<\/p>

This guide aims to bridge that gap. We will dismantle the conflicting “rules of thumb”\u2014ranging from the aggressive 1.5x Thickness to the conservative 4x Thickness\u2014and help you determine the exact minimum flange length required for reliable production.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\"\u6700\u5c0f\u30d5\u30e9\u30f3\u30b8\u9577\u898f\u5b9a\"\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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<\/p>

Defining the “Minimum Flange Length”<\/h2>

<\/p>

\u30e1\u30ab\u30cb\u30c3\u30af\u306e\u8a71\u306b\u5165\u308b\u524d\u306b\u3001\u9ad8\u4fa1\u306a\u30b3\u30df\u30e5\u30cb\u30b1\u30fc\u30b7\u30e7\u30f3\u30fb\u30a8\u30e9\u30fc\u3092\u907f\u3051\u308b\u305f\u3081\u306b\u3001\u5b9a\u7fa9\u3092\u4e00\u81f4\u3055\u305b\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002<\/p>

<\/p>

\u52a0\u5de5\u696d\u8005\u304c\u6700\u5c0f\u30d5\u30e9\u30f3\u30b8\u9577\u3055\uff08Lm_2098\uff09\u306b\u3064\u3044\u3066\u8a71\u3059\u3068\u304d\u3001\u305d\u308c\u306f\u30d5\u30e9\u30f3\u30b8\u306e\u5916\u5f62\u5bf8\u6cd5\uff08\u66f2\u3052\u90e8\u306e\u5916\u5074\u304b\u3089\u90e8\u54c1\u306e\u7aef\u307e\u3067\u306e\u5bf8\u6cd5\uff09\u3092\u6307\u3057\u3066\u3044\u307e\u3059\u3002\u3053\u306e\u5bf8\u6cd5\u306b\u306f \u66f2\u3052\u534a\u5f84 (R)<\/a> \u3068\u6750\u6599\u306e\u539a\u3055\uff08T\uff09\u3002<\/p>

<\/p>

\u3053\u306e\u8ddd\u96e2\u304c\u4e0d\u5341\u5206\u306a\u5834\u5408\u3001\u30d7\u30ec\u30b9\u30d6\u30ec\u30fc\u30ad\u306f\u7269\u7406\u7684\u306b\u5f62\u72b6\u3092\u4f5c\u308b\u3053\u3068\u304c\u3067\u304d\u305a\u3001\u30b9\u30af\u30e9\u30c3\u30d7\u90e8\u54c1\u304c\u767a\u751f\u3057\u307e\u3059\u3002<\/p>

<\/p>

\u7269\u7406\u5b66\u9650\u754c\u306f\u306a\u305c\u5b58\u5728\u3059\u308b\u306e\u304b\uff1f<\/h2>

<\/p>

\u306a\u305c\u6700\u5c0f\u9577\u3055\u304c\u5b58\u5728\u3059\u308b\u306e\u304b\u3092\u7406\u89e3\u3059\u308b\u305f\u3081\u306b\u306f\u3001\u7cbe\u5bc6\u52a0\u5de5\u306e90%\u3067\u4f7f\u7528\u3055\u308c\u308b\u6a19\u6e96\u7684\u306a\u88fd\u9020\u5de5\u7a0b\u3092\u898b\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\uff1a\u30a8\u30a2\u66f2\u3052\u3002<\/p>

<\/p>

In air bending, the sheet metal is placed on top of a bottom die, which typically has a V-shaped opening. A top punch descends, forcing the metal into the V-opening. Crucially, the metal is not pressed all the way to the bottom of the die. Instead, it “floats” on three distinct points of contact:<\/p>

<\/p>

  1. \u30c8\u30c3\u30d7\u30d1\u30f3\u30c1\u306e\u5148\u7aef\u3002<\/li>
  2. V\u30c0\u30a4\u306e\u5de6\u80a9\u3002<\/li>
  3. V\u30c0\u30a4\u306e\u53f3\u80a9\u3002<\/li><\/ol>

    <\/p>

    The “Bridge” Analogy<\/h3>

    <\/p>

    \u30b7\u30fc\u30c8\u30e1\u30bf\u30eb\u3092\u5ce1\u8c37\uff08V\u5b57\u958b\u53e3\u90e8\uff09\u306b\u67b6\u304b\u308b\u6a4b\u3068\u8003\u3048\u3066\u307b\u3057\u3044\u3002\u6a4b\u3092\u652f\u3048\u308b\u306b\u306f\u3001\u5ce1\u8c37\u306e\u4e21\u5074\u306e\u5805\u56fa\u306a\u5730\u76e4\u306b\u3057\u3063\u304b\u308a\u3068\u56fa\u5b9a\u3055\u308c\u3066\u3044\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\u3002<\/p>

    <\/p>

    If you design a flange that is too short, the material on one side will not reach the “shoulder” of the V-die. Instead of bending, the sheet will simply slip into the die cavity. This leads to three distinct failures:<\/p>

    <\/p>

    1. \u30b9\u30ea\u30c3\u30d7\u3068\u6b6a\u307f\uff1a<\/strong> The part slides sideways during the press cycle, creating a crooked or “dog-legged” bend line.<\/li>
    2. \u30ac\u30a6\u30b8\u30f3\u30b0\uff1a<\/strong> \u30b9\u30ea\u30c3\u30d7\u3057\u305f\u30b7\u30fc\u30c8\u306f\u3001\u9ad8\u4fa1\u306a\u30c0\u30a4\u30b7\u30e7\u30eb\u30c0\u30fc\u306e\u786c\u5316\u92fc\u306b\u98df\u3044\u8fbc\u307f\u3001\u91d1\u578b\u306b\u30c0\u30e1\u30fc\u30b8\u3092\u4e0e\u3048\u308b\u3002<\/li>
    3. \u30d0\u30c3\u30af\u30b2\u30fc\u30b8\u306e\u6545\u969c<\/strong> \u3053\u308c\u304c\u8a2d\u8a08\u8005\u304c\u898b\u843d\u3068\u3057\u304c\u3061\u306a\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u3002\u30d7\u30ec\u30b9\u30d6\u30ec\u30fc\u30ad\u306e\u30aa\u30da\u30ec\u30fc\u30bf\u30fc\u306f\u3001\u30d0\u30c3\u30af\u30b2\u30fc\u30b8\uff08\u6a5f\u68b0\u306e\u5f8c\u308d\u306b\u3042\u308b\u30ed\u30dc\u30c3\u30c8\u306e\u6307\uff09\u3092\u4f7f\u3063\u3066\u90e8\u54c1\u3092\u6b63\u78ba\u306b\u4f4d\u7f6e\u6c7a\u3081\u3057\u307e\u3059\u3002\u30d5\u30e9\u30f3\u30b8\u304c\u77ed\u3059\u304e\u308b\u3068\u3001\u30d0\u30c3\u30af\u30b2\u30fc\u30b8\u306e\u6307\u306b\u5c4a\u304d\u307e\u305b\u3093\u3002\u3053\u306e\u7269\u7406\u7684\u306a\u30b9\u30c8\u30c3\u30d7\u304c\u306a\u3051\u308c\u3070\u3001\u30aa\u30da\u30ec\u30fc\u30bf\u30fc\u306f\u76ee\u8996\u3067\u30d1\u30fc\u30c4\u3092\u4f4d\u7f6e\u6c7a\u3081\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u305a\u3001\u4e00\u8cab\u3057\u305f\u5927\u91cf\u751f\u7523\u306f\u4e0d\u53ef\u80fd\u3067\u3059\u3002<\/li><\/ol>

      <\/p>

      \u91cd\u8981\u306a\u5909\u6570\u30c0\u30a4\u5e45<\/h3>

      <\/p>

      V\u30c0\u30a4\u306e\u958b\u53e3\u90e8\u306e\u5e45\u306f\u4efb\u610f\u3067\u306f\u306a\u304f\u3001\u6750\u6599\u306e\u539a\u3055\uff08T\uff09\u306b\u57fa\u3065\u3044\u3066\u9078\u629e\u3055\u308c\u308b\u3002<\/p>

      <\/p>

      \u6a19\u6e96\u7684\u306a\u696d\u754c\u6163\u884c\u3067\u306f\u3001V\u30c0\u30a4\u306e\u958b\u53e3\u90e8\u306f\u901a\u5e38\u3001\u6750\u6599\u539a\u306e6\uff5e8\u500d\u3068\u3055\u308c\u3066\u3044\u308b\u3002<\/p>

      <\/p>