| 摘要 |
The present invention relates to a sheath heater. The present invention is a technique for lowering the defective rate of the sheath heater and ensuring economical efficiency in manufacture. More specifically, the present invention relates to a sheath heater, to an electric heating device facility using the same, and to packing on both end parts of the sheath heater necessary to manufacture the sheath heater. The present invention provides a sheath heater comprising: a pipe; a heating wire arranged inside the pipe; packing for hermetically sealing the inside of the pipe; and an electric heating material filled into the inner space of the pipe composed of the pipe and the packing, wherein the inner diameter of the pipe is made small by a pipe compression process, the packing is closely attached and fixated to the inner surface of the pipe before the pipe compression process, and the closely attached and fixated part increases after the pipe compression process. The present invention provides a manufacturing method and a sheath heater manufactured thereby, wherein air inside an inner sealing part is discharged to the outside in the pipe compression process by the configuration of the present invention even if the pipe compression process is performed after both ends of the sheath heater is packed once by physical insertion in contrast to a traditional method of configuring the packing of the sheath heater in many steps. Therefore, not only excessive pressure is prevented from being formed inside but also the introduction of external air or humidity is blocked without a separate process after the pipe compression process, thereby significantly reducing a manufacturing process and lowering a defective rate. |
