| 摘要 |
PURPOSE:To provide a highly reliable hot water tank at low cost of which manufacturing is facilitated by a method wherein a resin layer of super high molecular polyethylene is formed on an inner circumference surface of a barrel plate by a blow forming process and at the same time a super high molecular polyethylene resin layer is formed at inner walls of a pair of upper and lower end plates by a vacuum forming process, the resin layer at the junction surface of the barrel plates and the resin layer at the junction surfaces of a pair of upper and lower end plates are melted to each other by a rotary friction method. CONSTITUTION:An inner circumferential surface of a barrle plate 2 is applied with a blow forming process and the inner surfaces of a pair of end plates 3 are applied with a vacuum forming process, thereby a resin layer of super high molecular polyethylene is formed at each of the surfaces. Thus formed barrel plate 2 having resin layer and the end plates 3 are connected at the junction surfaces and when the end plates 3 are rotated at a high speed, the surfaces of the resin layers 4 and 5 at the junction part are melted and adhered to each other due to a frictional heat generating process. Since this connected part has a high mechanical strength, so that they are held with auxiliary hardware 7 to apply a mechanical strength. The hot water tank is made such that the inner surfaces of the barrel plate 2 and the end plates 3 are covered by resin layers 4 and 5 of super high molecular polyethylene, and the resin layers 4 and 5 have no pin holes at all, so that the corrosion in the end plates 3 as well as in the barrel plate 2 can be prevented. |
