关键词: 组合下横梁, 整体性, 临界预紧力, 影响因素

Abstract:

The lower beam of a large forging hydraulic press is usually assembled with a few pieces of beam body using some preload bolts due to the restrictions of the processing, transportations and installation conditions, so how to accurately calculate the pretension force become the crucial problems in strength, stiffness and integration property design of the assembled lower beam. A simplified analysis model of lower beam was assumed herein as a large forging hydraulic press prototype and the influence factors of critical pretension force in center and reaming working condition of the assembled lower beam were systematically studied,so as to find out the critical factors and the influence rules. The results show that the load and ratio of span and height are the critical factors, the beam width and bolt position have less influence on the critical pretension force, and the critical pretension force coefficient increases linearly with the increase of the ratio of span and height. On the other hand, the critical pretension force coefficientis also set when the ratio of span and height is as a fixed value. The experimental model of the assembled lower beam with the ratio 1∶7.2 was designed herein, which verifies the simulation results based on the model and provides a theoretical basis for the determination of the assembled lower beam of the large forging hydraulic press.

Key words: assembled lower beam, integration property, critical pretension force, influence factor