Characteristic Analysis And Experimental Study On Twin-valve Controlled Electro-hydraulic Vibration Device

In order to solve the technical problem that it is difficult to directly introduce a waveform vertical-shift control signal into the traditional electro-hydraulic vibration device to effectively control the balance position of vibration center and to realize the flexible adjustment of waveform frequency and amplitude.Combined with the existing rotary valve controlled electro-hydraulic excitation method,a twin-valve controlled electro-hydraulic vibration device is developed,based on the dislocation combination of two unit valve spools,and it can flexibly adjust the waveform frequency,amplitude and vertical-shift in the vibration system.The following research is carried out around the adjusting characteristics of its output vibration waveform.1.Based on the working principle of new structure,a twin-valve controlled electro-hydraulic vibration system are designed,and a control method for the output vibration waveform is proposed.The design calculation and mechanical modeling of the key structure of vibration device are carried out,the relevant technical requirements and parameters are determined,and the reasonable selection of driving motor is complted.2.The calculating model of the overlapping area and its gradient under the rectangular valve orifice,triangular valve orifice and circular valve orifice of twin-valve during the vibration commutation process are established.The influence of the parameters,such as the rotation angle and axial displacement of valve spool,the radius of shoulder and the number of evenly distributed orifice on shoulder,on the overlapping area and its gradient under three different shapes of valve orifices are analyzed.The overlapping area and its gradient characteristic curves under three different valve orifece are obtained.3.Analyzed the mathematical relationship between the load flow,load pressure,spool rotation angle,and spool axial displacement of twin-valve controlled vibration device under steady conditions,deduced the valve coefficient expression,and obtained the static characteristic curves of twin-valve.The hydrodynamic calculating model of twin-valve is put forward,the basic characteristic governing equations and transfer function of twin-valve controlled vibration power mechanism are established,and their dynamic characteristics are analyzed.4.The numerical solving model of the output vibration waveform of twin-valve controlled electro-hydraulic vibration system and the experimental prototype of the vibration device are built.The influence rules of rotary speed of servo motor,oil supply pressure,axial displacement and the relevant structural parameters of valve spool on output vibration waveform frequency,amplitude and vertical-shift of the vibration device are studied.The research results show that when the wave frequency is 10～100 Hz,the wave amplitude can be adjusted in the range of 1～8 mm,and meanwhile the wave amplitude can be further increased by increasing the axial displacement of valve spool;when the axial displacement ratio of valve spool is 0.4～1.0 at 20 Hz waveform frequency,the waveform vertical-shift can be adjusted in the range of 0～10 mm.In summary,this paper provides a new type of electro-hydraulic vibration device and its waveform control method,and it can meet the requirements of high-end equipment manufacturing industry for the output vibration waveform adjusting performance of electro-hydraulic vibration device.Figure[89]table[8]reference[68]...