Patent ID: 8806755

Claim:
A manufacturing method of a pad spring used in a vehicle disc brake, the method comprising: a pad spring manufacturing step of pressing a metal sheet to manufacture a pad spring; a pad spring heat treatment step of heat treating the pad spring manufactured at the pad spring manufacturing step; a pad spring sanding step of sanding a surface of the pad spring heat treated at the pad spring heat treatment step; and a pad spring coating step of coating the surface of the pad spring sanded at the pad spring sanding step, wherein the pad spring sanding step comprises sanding the surface of the pad spring heat treated at the pad spring heat treatment step through the use of a sanding device wherein the sanding device comprises: a storage tank to store a sanding material; a basket to receive a plurality of pad springs heat treated at the pad spring heat treatment step; a casing unit to an inside of which the basket is rotatably fixed, the casing unit having an opening and closing door; a fixing unit to removably and rotatably fix the basket to the opening and closing door; an injection unit to receive the sanding material from the storage tank, to receive compressed air from an external compressed air supply device, and to inject the sanding material and the compressed air into the basket; and a supply pipe to supply the sanding material stored in the storage tank to the injection unit, the supply pipe being configured such that opposite ends of the supply pipe extend through opposite sides of a lower part of the storage tank, wherein an air control valve is provided at one end of the supply pipe, an introduction port, through which the sanding material is introduced, is formed at a middle part of the supply pipe, and the other end of the supply pipe is connected to the injection unit, and wherein the pad spring sanding step further comprises: operating the sanding device in cycles of 15 to 30 minutes per cycle; and introducing 100 to 300 pad springs into the basket each cycle.