以前面的例子来说，在气缸活塞和汽化器到位前，将发动机装配到摩托车架是没有意义的。

Using the example from earlier, it does not make sense to mount the engine of the bike to the frame of the bike before the pistons and carburettor are in place yet.

youdao

本文原型系统通过发动机部件活塞连杆装配体加以验证，表明了系统的可行性和有效性。

The verification of assembly modeling system by taking example for piston and connecting rod indicates the feasibility and validity of the system.

youdao

结果表明，导致活塞销失效的主要原因是活塞销内表面在发动机装配使用前存在折叠裂纹。

The results indicate that the main reason causing the failure of the piston pin is fold cracks in inner-surface of the piston pins existing before that the engine is assembled and tested.

youdao