对超声波塑料焊接过程进行了分析 ,发现在焊接接头经历熔化开始、铺展、熔融层形成、熔融物挤出及接头凝固不同阶段中 ,压力的作用也不尽相同。传统焊机的压力不变模式使得焊接工艺很难优化。为此本文利用VEP3 1 2压力控制型电气比例阀在能量模式控制的超声焊机基础上 ,首次实现了压力在焊接过程中的可变调节 ,使得焊机能够优化焊接压力 ,从而为接头质量优化奠定了硬件基础。 Ultrasonic plastic welding process was analyzed and found that the role of pressure in different stages of the beginning of the weld joint melting, spreading, the formation of the molten layer, melt extrusion and the joint coagulation are also different. The traditional constant pressure welding machine makes the welding process difficult to optimize. In this paper, based on the energy mode control ultrasonic welder, the VEP312 pressure-controlled electrical proportional valve is the first time that the pressure can be variably adjusted in the welding process so that the welding machine can optimize the welding pressure and optimize the joint quality Laid the hardware foundation.