大多数发动机运转为四行程循环。

Most automobile engines operate on four stroke cycle.

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在四行程循环时，每凸轮必须旋转打开一阀门。

Each CAM must revolve once during the four-stroke cycle to open a valve.

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通过操作面板选择，不仅可实现定程、定压两种成形工艺，而且可实现有垫、无垫、顶出三种工艺工作循环。

Through the operation panel, not only can realize the fixed distance and constant pressure of two kinds of forming process, and can realize a pad, pad free, top three cycle process.

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