【作者】 刘亮；

【导师】 霍军周； 段众高；

【作者基本信息】 大连理工大学 ， 机械工程（专业学位）， 2016， 硕士

【摘要】 惯性振动落砂机属于惯性往复振动机械的一种应用,其主要作用是通过振动作用将铸造用型砂破粹、分离。由于铸件及型砂质量较大,在实际使用过程中,对落砂机会产生较大的冲击和碰撞,落砂机内部结构较薄弱的部位会出现疲劳破坏。因此,对惯性振动落砂机的结构强度及振动情况的研究有很重要的意义。本论文运用三维建模软件PRO/E对实际使用中的惯性振动落砂机进行实体建模,并运用有限元分析软件ANSYS对建立的落砂机实体模型进行了静力学和动力学分析,得到了落砂机在施加激振力载荷后的变形情况和受应力状态,找出了结构强度薄弱部位；并且通过多刚体动力学仿真软件ADMAS进行了落砂机的运动学分析,得到了激振力、弹簧刚度及偏心块回转速度对振动情况的影响。具体如下：1、静力学分析时,落砂机在受到电机向上和向下瞬时最大激振力时,最大应力均出现在电机连接凸台与落砂机拉力管连接侧板,平均应力在30到40MPa,远小于落砂机材料的屈服极限,落砂机的结构强度符合设计要求。并且对落砂机结构轻量化设计后,落砂机重量减轻15.6%,同时机械性能符合设计要求。2、落砂机自由模态的第1阶模态频率为38Hz,整机模态固有频率较高,设计较为保守,并且机体侧板相对较为薄弱,在高频率振动下容易导致扭曲变形；施加弹簧约束后,落砂机在第4阶模态(22Hz)时达到最优模态振型,为整机沿垂直方向(Z向)作上下振动。3、根据谐响应分析,在选用落砂机工作频率时应避免低频和高频的范围,选用22Hz的工作频率,节点响应幅值为1.2mm,既能达到落砂机的最佳振动状态,也不会产生较大的响应幅值,可以避免落砂机的扭曲变形和有害共振,从而延长落砂机使用寿命。4、通过对落砂机振动系统的运动学分析,落砂机振动系统的振动位移、速度和加速度均随激振力及偏心块的回转速度增加而增大,随着弹簧刚度的增加而减小；并且偏心块的回转速度对振动系统的振动幅值影响较大；低回转速度下,弹簧刚度对振动系统影响不明显,但是较大的弹簧刚度能使振动系统更快趋于稳定。更多还原

【Abstract】 The inertial vibration shakeout machine is one application of the inertial reciprocating machinery, its main role is to break and separate the casting pure foundry sand through the vibration. Due to the large quality of the casting and sands, which has great collisions to the shakeout machine, the fatigue failure will be found in the weaker parts of the internal structure of the shakeout machine in actual using process. Therefore, the study of structural strength and vibration analysis of the inertial vibration shakeout machine is very significant.In this paper, the 3D modeling software PRO/E was used for solid modeling and the statics and dynamics analysis was finished by the finite element analysis software ANSYS, the deformation and stress state of the shakeout machine was performed by applying a excitation force, which identified the weak parts of the structural strength; the kinematics analysis of the shakeout machine vibration system was simulated by the multi-body dynamics simulation software ADMAS, which performed the influence to the vibration conditions with exciting force load, spring stiffness and rotation speed of the eccentric block. The conclusions are as follows:1 In the static analysis, the maximum stress occurred at the motor side connected with the coupling boss of the shakeout machine when the machine is forced the up and down of the instantaneous maximum exciting force, the average stress was 30 to 40MPa, far less than the shakeout machine material yield strength, the shakeout machine structural strength meet the design requirements. The weight of the shakeout machine loses 15.6% after lightweight design, while the mechanical properties meet the design requirements.2 The first order modal frequency of the shakeout machine free modal is 38Hz, which is more conservative design because of the high natural frequency, and the body side is relatively weak, which is easily to be distortion under the high frequency vibration; applying spring constraints, the shakeout machine achieved optimal mode shape in the 4th-order mode (22Hz), for the vertical vibration in the vertical direction (Z direction).3 According to the harmonic analysis, the choice of shakeout machine operating frequency should avoid low-frequency and high-frequency range, in the operating frequency of 22Hz, node response amplitude reached 1.2mm, which can achieve the best shaker state and does not produce greater response amplitude to avoid distortion and unwanted resonance, thus prolonging the life of shakeout machine.4 Through the kinematics analysis of the shakeout machine vibration system, the vibration displacement, velocity and acceleration augment with the increasing of the exciting force and the rotation speed of the eccentric block, decrease with the increasing of the spring stiffness; and the vibration amplitude of the vibration system is influenced observably by the rotation speed of the eccentric block; at low rotational speed, the spring stiffness of the vibration system is not obvious to the vibration system, but the larger spring stiffness enables vibration system to stabilize faster.更多还原