Nissan Motor Company Limited

Yoshito Utsumi

Eiji Shiotani

Yoshitsugu Noshi

Hirohisa Shibayama

Akira Shimizu

Hidenobu Matsuyama

Daisuke Terada

Satoru Sakurai

Tsuyoshi Higuchi

Kiyokazu Sugiyama

Hayato Hirayama

Koukichi Kamada

Naoya Tainaka

Haruhiko Suzuki

Toshio Ogiya

Hiroaki Hoshikawa

Hiroaki Mochida

Masami Tashiro

Hiroshi Hatta

Shuji Adachi

A film forming method forms a coating film on a workpiece having at least two film-deposited portions which are not continuous with each other by moving a nozzle of a cold spray device relative to each other along a continuous movement trajectory. The movement trajectory includes at least two trajectories corresponding to the film-deposited portions and a connecting trajectory linking the trajectories of the film-deposited portions. The film-deposited portions are formed by continuously spraying a raw material powder from the nozzle by cold spraying to form a coating film on each of the plurality of film-deposited portions. A turnback point of the spraying is set on the connecting trajectory where a relative speed between the workpiece and the nozzle decreases in the movement trajectory.

Film forming method

The present invention provides a thermally sprayed coating that is a thermally sprayed iron-based coating formed on an inner circumferential surface of a cylinder bore of an aluminum or aluminum alloy cylinder block. The thermally sprayed coating has a plastic deformation part on its surface. Thus, pores on the surface of the thermally sprayed coating are reduced, resulting in a reduction in the amount of oil consumption.

Sprayed coating and sprayed-coating manufacturing method

Provided is a spray coating that is disposed on an inner peripheral surface of a cylinder bore of a cylinder block made of aluminum or an aluminum alloy. The spray coating contains 0.005% to 0.14% by mass of carbon, 0.01% to 3.0% by mass of nickel 10% to 20.5% by mass of chromium, 0.05% to 1.5% by mass of silicon, and a balance containing iron and inevitable impurities. The spray coating has a composition that forms a martensite+ferrite (M+F) region in the Schaeffler diagram, and a composition in which a nickel equivalent (NiE) and a chromium equivalent (CrE) satisfy a relationship expressed by the following Formulae (1): NiE≤0.95 CrE−8.59, (2): NiE≤4.1, and (3): CrE≥10. The spray coating has a two-phase structure formed of a martensite phase and a ferrite phase.

Spray coating

A film forming method forms a coating film on a workpiece (e.g., a cylinder head) having a film-deposited portion (e.g., an annular valve seat part) by moving a nozzle of a cold spray device relative to the workpiece along a film formation trajectory having a film formation starting point and a film formation finishing point in which the film-deposited portion overlaps to form an overlapping portion. The coating film is formed by causing a raw material powder to collide in a solid-phase state with the workpiece and plastically deform. Also, the coating film on the film-deposited portion is further formed such that an inclination angle of an end part of the coating film relative to a surface of the film-deposited portion is 45&#xb0; or less at the film formation starting point of the overlapping portion.

Film formation method

A thermal spraying torch configured to spray a molten material onto a thermal sprayed surface of a work object and form a thermal sprayed coating has a discharge port configured to discharge the molten material, a discharge port periphery located on a peripheral edge of the discharge port on a front side in a discharge direction of the molten material and extending in the discharge direction, and an external surface continuous with a front end of the discharge port periphery. The discharge port periphery includes first section to which the molten material adheres more easily than to the external surface. The external surface includes a second section to which the molten material adheres less easily than to the discharge port periphery.

Thermal spraying torch

Provided is a defect detection device capable of measuring the volume of surface defects. The defect detection device includes: an imaging device configured to image an image of an inspection object; a binarization processing unit configured to subject the image to first and second binarization processing by use of different first and second binarization thresholds, so as to calculate first and second sizes for an identical defect in the image; a ratio calculation unit configured to calculate a first ratio of the second size to the first size; and a depth determination unit configured to determine a depth of the defect depending on the first ratio.

Defect detection device and production system

A method for processing a cylinder block is disclosed, wherein a protrusion protruding toward a crankcase is provided at a crankcase-side edge of a cylinder bore and a sprayed coating is formed on an inner surface of the cylinder bore and an inner surface of the protrusion continuous with the inner surface of the cylinder bore. After forming the sprayed coating, at least part of the protrusion is removed together with the sprayed coating formed on the inner surface of the protrusion. Accordingly, even in the case of removing the edge portion of the cylinder bore on the crankcase side, a sufficient margin to be removed can be ensured while a reduction in size of the cylinder block is achieved.

Method for processing cylinder block, cylinder block and thermal-sprayed cylinder block

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Kanagawa, Japan

Yoshito Utsumi