Valve element assembly and thermostatic expansion valve

The utility model relates to a valve core assembly of a thermostatic expansion valve, which is mounted in a valve body and used for controlling opening/closing of a valve port in the valve body. The valve element assembly comprises a valve needle, a first elastic piece and a mounting base, the valve needle is arranged at one end of the first elastic piece, and the end, away from the valve needle, of the first elastic piece abuts against the mounting base. The valve element assembly further comprises a sleeve, the sleeve is arranged on the mounting base, the valve needle and the first elastic piece are both located in the sleeve, the valve needle is arranged in the sleeve in a sliding mode, and the valve element assembly can be adjusted up and down in the central axis direction of the valve body. The device has the effect of being convenient to replace. 本申请涉及热力膨胀阀的阀芯组件，阀芯组件安装于阀体内，用以控制阀体内阀口的启/闭；其中，阀芯组件包括阀针、第一弹性件以及安装座，阀针设置于第一弹性件的一端，第一弹性件远离阀针的一端抵靠于安装座上；阀芯组件还包括套筒，套筒设置于安装座上，阀针和第一弹性件均位于套筒内，阀针沿套筒内滑动设置，阀芯组件可沿阀体的中轴线方向可