Rotating brake member of braking device for vehicle and method for antirust treatment thereof
AssigneesKiriu Corporation, Nihon Parkerizing Co., Ltd.
InventorsHiroshi Uehara, Nobuaki Nagashima, Kosuke Hatasaki, Ryosuke Kawagoshi, Motoharu Murata
Life of this patent
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Abstract
In a cast-iron disc brake rotor (1), each of an outer sliding surface (2a) and an inner sliding surface (3a) is covered with a phosphate coating (8) by electrolysis of a phosphate coating solution containing therein phosphate ions, zinc ions and nitrate ions. This makes it possible to attain dramatically improved rust preventive performance for the sliding surfaces (2a) and (3a). The phosphate coating (8) has a thickness of 1 to 10 μm, a mass of 4 to 35 g/m2 and a grain size of less than 50 μm. Preferably, the thickness of the phosphate coating (8) is adjusted to 2 to 8 μm.
Claims11
A rust proofing process for a rotary braking member, the braking member being formed into a disc or drum shape and made of an iron material, the process comprising the steps of:
- subjecting the braking member to degreasing;
- and after said degreasing, forming a phosphate coating on at least a portion of the braking member adapted to be used as a sliding surface against an opposing frictional member, by electrolysis of a phosphate coating solution containing 20 to 70 g/l of phosphate ions, 20 to 50 g/l of zinc ions and 30 to 80 g/l of nitrate ions, in such a manner that the phosphate coating has a thickness of 1 to 10 μm, a mass of 4 to 35 g/m2 and a grain size of 50 μm or less.
A rotary braking member for use in a vehicle brake system, the braking member being formed into a disc or drum shape and made of an iron material and comprising at least a portion to be used as a sliding surface against an opposing frictional member covered with a phosphate coating, the phosphate coating being formed by performing electrolysis of a phosphate coating solution that contains phosphate ions, zinc ions and nitrate ions, in such a manner that the phosphate coating has a thickness of 1 to 10 μm, a mass of 4 to 35 g/m2 and a grain size of 50 μm or less.
A rust proofing process for a rotary braking member, the braking member being formed into a disc or drum shape and made of an iron material, the process comprising the steps of:
- forming a phosphate coating on at least a portion of the braking member to be used as a sliding surface against an opposing frictional member, by electrolysis of a phosphate coating solution containing phosphate ions, zinc ions and nitrate ions, in such a manner that the phosphate coating has a thickness of 1 to 10 μm, a mass of 4 to 35 g/m2 and a grain size of 50 μm or less.
A rotary braking member for use in a vehicle brake system, the braking member being formed into a disc or drum shape and made of an iron material and comprising at least a portion adapted to be used as a sliding surface against an opposing frictional member covered with a phosphate coating, the phosphate coating being formed by subjecting the braking member to degreasing and, after said degreasing, performing electrolysis of a phosphate coating solution that contains 20 to 70 g/l of phosphate ions, 20 to 50 g/l of zinc ions and 30 to 80 g/l of nitrate ions, in such a manner that the phosphate coating has a thickness of 1 to 10 μm, a mass of 4 to 35 g/m2 and a grain size of 50 μm or less.
Dependencies are inferred from the claim text.