【正文】 n （臺板；焊機(jī)床面）: One piece with or without a discard （丟棄；拋棄；放棄）shear and/or with a discard sawc. Columns: Round columns with inboard and external nuts, round columns with pression sleeves （套筒；套管）(tubular) and external nuts, lamellar （薄片狀的；薄層狀的）tension elements with pression membersd. Bed plate（底板）: Standard with round columns● Moving crosshead （聯(lián)桿器，十字頭）, consisting of stem holder , return cylinders, and, if necessary, advance cylinders● Container holder with containermoving cylinders● Die slide or short die carrier, rotating die carrier, or stationary tool carrier acting as the die holder● Discard shear and/or discard sawThe function of the press frame is to withstand the extrusion load. A prestressed stiff press frame provides:● Low press extension● Low de?ection （撓度）of the die support ● Short depression timeThe press frame consists of a cylinder housing with the main cylinder and ram, a platen, and, if the four columns are not designed as tension and pression elements, a bed plate and guide.The elastic behavior of the press frame under production conditions is an important characteristic of the extrusion press. The stiffness （剛度） of the machine influences the accuracy of the guiding and the die support during extrusion.In many respects, the quality of the press frame plays an important role in the extrusion process. The operational reliability must first be guaranteed. Failures in the column threads（螺紋） must be avoided at all costs. The notch（刻痕）effect at the root of the thread can increase the normal stress by a significant factor. In practice, only the first threads can transfer the forces. This disadvantage is avoided with hammer head lamellar columns. The geometry of the hammer head can be optimized by finite element analysis. In the area of the cylinder housing and the platen, prestressing with round columns is carried out, using inboard and external nuts. There is no prestressing between the housing and the platen, resulting in a relatively large elongation of the press during extrusion. If hollow pression members are located between the housing and the platen instead of the inboard nuts, then this is referred to as a fully prestressed press frame.With prestressed columns designed so that the tension elements are more highly stressed and the pressive elements subjected to lower stresses, the elongation can be reduced to 50% or less of that of nonprestressed columns with normal dimensions （規(guī)模，大?。?For example, for a MN rodandtube press with a column length of 12 m and an extrusion load of 30 MN, the elongation for a prestressed press frame is approximately mm and approximately 5 mm for a nonprestressed press frame. Figure pares the load elongation diagrams for both tension and pression elements and columns with nuts for this press frame.Fig. Load diagram of a prestressed and nonprestressed press frame at a load of MN. g, platen。k?mpenseit] 補(bǔ)償highthroughput高生產(chǎn)量adjacent[?39。swi?i?] 旋轉(zhuǎn)的upsetting [?p39。teit] 旋轉(zhuǎn)frame[freim] 框,結(jié)構(gòu),骨架auxiliary [?:ɡ39。lei??n] 操作；操縱；處理clamped[kl230。k?mp230。?ptimaiz] 使最優(yōu)化，使完善foreground [39。meintin?ns]維護(hù),保持,維修monitor [39。p?:??n] 比例；大小prestressed [pri:39。 within an extrusion cycle, required extensive maintenance and regular repair. Only a few presses were built to this design and actually used for production. In general, shortstroke presses are more expensive than standardstroke presses because of the manipulation needed for billet loading and the mechanical design.注釋：bore [b?:] (管、圓筒的)空心部分，膛孔.emerges [i39。fistikeitid] 富有經(jīng)驗(yàn)的；精致的；復(fù)雜的 Extrusion Press Design PrinciplesInitial discussions, over 50 years ago, to rationalize the construction of extrusion presses, resulted in the standardization of extrusion tooling in (DIN 24540). Within the last 30 years, the press manufacturing panies have introduced standardized designs onto the market.Table shows the features of extrusion presses for light metals, heavy metals, and steel.The main feature of the directextrusion press is the stationary container during extrusion. The die, which is also stationary, and the support tooling are located at one of the end faces of the container, in front of the container bore（ (管、圓筒的)空心部分，膛孔）. Opposite the die, the dummy block located in front of the extrusion stem pushes the billet through the container bore, and the section emerges（形成，出現(xiàn)）through the die (Fig. ).Fig. Tool arrangement for direct extrusionFig. Geometric relationships for different designs for direct extrusionThe geometric proportions (比例；大小)for different designs for direct extrusion are shown in .The most mon design of extrusion press today is the prestressed(預(yù)應(yīng)力的)fourcolumn press(四柱壓力機(jī)). It is usually built with a standard stroke（行程，沖程）, which provides good access and easy maintenance（維護(hù),保持,維修）.In a standardstroke press, the billet is loaded between the container and the stem. The press stroke is determined by the loading stroke and the extrusion stroke. There are no specific requirements placed on the quality of the billet geometry。p230。st230。vei?] 輸送帶stretcher [39。nz39。intigreitid] 整合的longitudinal [,l?nd?i39。??n?lai39。r?uli?] 滾壓；軋制