Variable-stiffness spring type safety valve

The utility model discloses a variable-stiffness spring type safety valve, belongs to the technical field of safety valves, and realizes the effects that the spring stiffness of the safety valve is a piecewise function of a stroke, the stiffness is relatively small in an idle stroke section and the stiffness is increased in an auxiliary stroke section, and the difference value of opening and closing loads is reduced. The spring load when the safety valve is fully opened is closer to the maximum load of the medium on the valve clack when the valve is fully opened, the opening and closing pressure difference of the spring type safety valve is reduced, and steam waste of a power plant is avoided. 一种变刚度弹簧式安全阀，属于安全阀技术领域，本发明实现了安全阀的弹簧刚度为行程的分段函数，在空行程段，刚度较小，在辅助行程段，刚度变大，降低启闭载荷的差值，使安全阀全开时弹簧载荷与阀门全开时阀瓣受介质最大载荷更加接近，减小弹簧式安全阀的启闭压差，避免电厂的蒸汽浪费。