Nissan Motor Company Limited

Hirohisa Shibayama

Naoki Okamoto

Eiji Shiotani

Hidenobu Matsuyama

Yoshitsugu Noshi

Koukichi Kamada

Yoshito Utsumi

Naoya Tainaka

Akira Shimizu

Daisuke Terada

Kiyokazu Sugiyama

Haruhiko Suzuki

Satoru Sakurai

Masatoshi Inoguchi

Junichi Hamasaki

Toshio Ogiya

Masahito Fujikawa

Kenji Yageta

Masahiro Oomori

Moriyuki Nogami

A film formation portion is formed on an annular edge portion along an opening portion () of an intake port () or an opening portion () of an exhaust port (). The cross section, along the radial direction of the intake port () or the exhaust port (), of the film formation portion, on which a metal film () is formed by spraying a raw material powder using a cold spray method, is formed in a groove shape that includes a flat bottom surface (G) and a pair of side surfaces (G) adjacent to the bottom surface.

Cylinder head blank and cylinder head manufacturing method

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 nozzle for cold spray () used in a cold spray apparatus () is configured to include a tubular nozzle main body () and a cooling jacket () that surrounds the nozzle main body () to form a flow path () for refrigerant (R) between the nozzle main body () and the cooling jacket (). The cooling jacket () is provided with a seal retaining portion () that retains an O-ring () for the flow path (). The seal retaining portion () and the nozzle main body () are joined in a socket-and-spigot joint fashion.

Cold spray nozzle and cold spray device

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

When forming valve seat coats at opening portions (to) of intake ports () provided at a cylinder block mounting surface () of a semimanufactured cylinder head (), the nozzle of a cold spray apparatus moves along a nozzle movement path for air intake (Inp) that is set between any two of the plurality of opening portions (to), while continuing to spray a raw material powder. When forming valve seat coats at opening portions (to) of exhaust ports (), the nozzle moves along a nozzle movement path for air exhaust (Enp) that is set between any two of the plurality of opening portions (to), while continuing to spray the raw material powder.

Coating method

The disclosure includes manufacturing a semimanufactured cylinder head () having a shielding curtain portion () and spraying metal powder (P) onto an annular valve seat portion () using a cold spray method to form a valve seat film (). The shielding curtain portion () projects in an annular shape from an annular edge portion of an opening portion () of an intake port () or an opening portion () of an exhaust port () toward the center (C) of the port. The annular valve seat portion () is located on an outer side of the port than the shielding curtain portion ().

Method for manufacturing cylinder head, and semimanufactured cylinder head

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

Growing community of inventors

Kanagawa, Japan

Hirohisa Shibayama