Denso Corporation

Mikiya Kurita

Shouichi Takenouchi

Katsumi Nagasaka

Hiroyuki Dekita

Kouichi Ohta

Motofumi Kuzuno

Akinori Harata

Kengo Takeshita

Shoichi Takenouchi

A press has a die unit, a feed mechanism and a table unit. The feed mechanism feeds a sheet of material to the die unit. The die unit has a punch and a die for punching first and second holes in the sheet. The punching axis of the punch is inclined at an acute angle with respect to the sheet. The table unit supports the die unit and rotates the die unit with respect to the sheet to direct the punching axis in different directions to form the first and second holes in different directions.

Method and apparatus for manufacturing a press-formed object

It is an object of the invention to provide a method of working an injection hole of an electromagnetic type fuel injection valve so that when extrusion by using a punch is adopted, the punch does not break, even in the case where a central axis line of the injection hole of the electromagnetic type fuel injection valve is inclined to a line perpendicular to a face of a plate-like material to be punched. A front end, tapered portion of the punch is inclined in a direction opposed to a plate-like material relative to a central axis line of the punch to facilitate the punch along a sliding, inner face of a punch holder. While achieving a reduction in production cost, the divergent-shaped injection hole can accurately be formed in the plate-like material. A side force (Fs) is produced when the front end portion of the punch impinges on the plate-like material. The side force (Fs) is canceled by a reaction force (Fr) on a side opposed to the plate-like material and a bending moment potentially causing breakage of the punch is avoided.

Apparatus and method of working injection hole of fluid injection nozzle

A manufacturing method and a press apparatus improve the productivity of the manufacture of a press-formed object from a sheet blank, such as a nozzle hole plate of a fuel injector. The nozzle hole plate of a fuel injector has a plurality of holes differing, for example, in size and punch direction with respect to the sheet blank. In the case of the manufacture of a nozzle hole plate, a first amount of nozzle holes of equal punch angle and size are formed continuously by a die unit in a bandlike sheet blank workpiece while the workpiece is fed through the die unit one way in its length wise direction. Then, the feed direction is reversed, and the die unit is rotated and a further amount of nozzle holes are formed continuously by the same die unit. As a result, the number of die unit positioning operations involved in forming a quantity of nozzle hole plates is equal only to the number of different nozzle holes formed in each nozzle hole plate. The greater the number of nozzle hole plates manufactured from a single roll of bandlike sheet, the more manufacturing labor is saved, and the greater productivity is improved.

In a method for manufacturing a nozzle hole plate suitable for use in a fuel injection valve, a nozzle hole is formed at a predetermined angle of inclination by press-working with a punch in a thin-plate base material of a nozzle hole plate. When the nozzle hole is formed by press-working, a bluntness (shear drop) and a break face are formed at the corners of the base material at the fluid entrance and the fluid exit of the nozzle hole respectively, and as a result of the formation of this shear drop and break face the flow changes and the injection quantity increases. The injection quantity of the nozzle hole is measured for each nozzle hole plate, and its deviation from a target value is detected. Then, on the basis of the measured injection quantity value, the base material around the fluid entrance of the nozzle hole is notched by press-working using a punch. The material of the base material dimpled by the notching is pushed toward the fluid entrance of the nozzle hole and the shear drop diminishes. Consequently, the quantity of fuel injected through the nozzle hole plate decreases. Thus it is possible to provide a nozzle hole plate and a manufacturing method thereof with which a required injection quantity can be obtained in a short working time.

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Toyoake, Japan

Mikiya Kurita