真空铸铁骨架
钢琴的铸铁板需要承受来自琴弦的强大拉力，当达到440赫兹时，这种拉力甚至会增加到20吨之巨。预先加顶的音板与共鸣盘牢固地粘连在一起，而铸铁板则恰好位于其上。所用的圆周形的固定条或者红山毛榉木做的铁板框都是严格地按照音板的曲率进行安装的，这就使铁板固定的高度恰到好处。这种设计，使琴弦发出的全部频谱的震动都能够被音板自由地放大，而不至于被其所负载的沉重组件吸收掉。这样的系统能够保证琴弦震动不受任何阻力和音调损失而得到更加完整的传导。内围框部分由18层硬木压合板制成。当与外围框部分相连时，整架卧式钢琴总共将使用28层的硬木压合板。钢板受到来自琴弦的张力，因此必须在结构上与内围框牢固相连。钢板不仅要拥有诱人而永不过时的设计，而且还要能够影响乐器的声音效果。所有钢板的装配都是在室内进行的。这就意味着用于安装挂弦针、码针、弦轴和螺栓的600多个手工钻孔都要使用多种控制措施来确保其精密性。
the metal frame ofa piano needs to take the strong tension from the strings which may be up to 20tons when it reaches 440 hz. it’s right upon the pre-capped soundboard firmlyadhered with the allow. the circular fastening bars or red beech wood ironframework are strictly installed according to the curvature of the soundboardto properly fasten the iron plate. such design allows the string vibrations ofall spectrums to be freely amplified by the soundboard and not absorbed by itsheavy components. this system further ensures that string vibrations are morecompletely transmitted without any interference and tone loss. the innerenclosure frame is composed of 18 layers of hardwood plywood. when it’s connectedwith the outer enclosure frame, a grand piano needs 28 layers of hardwoodplywood. taking in the tension from strings, the steel plates must be firmlyconnected with the inner enclosure frame structurally. therefore, they need tohave an attractive and timeless design, and affect the sound effect of themusical instrument. all steel plates are installed indoor. hence, multiplecontrol measures must be taken to ensure the precision of some 600 hand-madedrill holes for the installation of spikes, pins and screw bolts.

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