Cylinder head cover and method of manufacturing the cylinder head cover

1. A cylinder head cover in a blowby gas recirculation system that flows a blowby gas generated in an internal combustion engine from the internal combustion engine into an intake passage, the cylinder head cover comprising:

a main body that is a resin or metal molded component, that is provided so as to cover a cylinder head of the internal combustion engine, and that collects the blowby gas; and

a side projection portion that is provided so as to project from a side of the main body and that discharges the blowby gas toward the intake passage,

wherein

the side projection portion and the intake passage are connected with a pipe,

the main body includes a main body gas passage that leads the collected blowby gas to the side projection portion, the main body gas passage having a predetermined passage cross-sectional area,

the cylinder head cover includes a cover gas passage through which the blowby gas flows from the main body gas passage to an outlet of the side projection portion, the cover gas passage having a minimum passage cross-sectional area portion in which a passage cross-sectional area of the cover gas passage is the smallest, the passage cross-sectional area minimum portion being provided not in the side projection portion but in the main body gas passage,

the main body has a hole for attaching a pressure detector that detects a pressure in the main body gas passage from an outside of the main body or a projection branch passage for connecting the pressure detector from the outside of the main body at a position downstream of the minimum passage cross-sectional area portion, and

the main body, the side projection portion, and the hole or the projection branch passage are integrally molded.

2. The cylinder head cover according to claim 1 , wherein

in a case where the main body has the hole, when the cylinder head cover is attached to the internal combustion engine, the hole is formed on a side opposite to the cylinder head and is opened to the side opposite to the cylinder head, and

in a case where the main body has the projection branch passage, when the cylinder head cover is attached to the internal combustion engine, the projection branch passage is formed on the side opposite to the cylinder head to project to the side opposite to the cylinder head.

3. The cylinder head cover according to claim 1 , wherein

the main body gas passage includes a labyrinth passage portion which is formed like a labyrinth, and a connection passage portion that connects an outlet of the labyrinth passage portion and the side projection portion, and

the minimum passage cross-sectional area portion, and the hole or the projection branch passage are provided in the connection passage portion.

4. The cylinder head cover according to claim 1 , wherein

in a case a height of the cylinder head cover in a direction from a side of the cylinder head to a side opposite to the cylinder head is referred to as a cylinder head cover height when the cylinder head cover is attached to the internal combustion engine,

the minimum passage cross-sectional area portion is provided at a portion of the cylinder head cover where the cylinder head cover height is lower than a surrounding cylinder head cover height.

5. A method of manufacturing a cylinder head cover in a blowby gas recirculation system that flows a blowby gas generated in an internal combustion engine from the internal combustion engine into an intake passage,

the method comprising:

providing a main body that is a resin or metal molded component, that covers a cylinder head of the internal combustion engine, and that collects the blowby gas;

providing a side projection portion that projects from a side of the main body and that discharges the blowby gas toward the intake passage;

setting a main body gas passage that leads the collected blowby gas to the side projection portion in the main body, the main body gas passage having a predetermined passage cross-sectional area;

providing a cover gas passage through which the blowby gas flows from the main body gas passage to an outlet of the side projection portion, the cover gas passage having a minimum passage cross-sectional area portion in which a passage cross-sectional area of the cover gas passage is the smallest;

setting the minimum passage cross-sectional area portion not in the side projection portion but in the main body gas passage;

setting a hole for attaching a pressure detector that detects a pressure in the main body gas passage from an outside of the main body or a projection branch passage for connecting the pressure detector from the outside of the main body at a position downstream of the minimum passage cross-sectional area portion in the main body;

forming the main body with a first mold and a second mold at least one of which is movable along a main body mold draft direction;

forming the side projection portion with a side mold that is movable along a side mold draft direction that is an axial direction of the side projection portion and is a direction different from the main body mold draft direction; and

forming the hole or the projection branch passage with one of the first mold and the second mold, or the side mold, to integrally mold the main body, the hole or the projection branch passage, and the side projection portion.

6. The method of manufacturing the cylinder head cover according to claim 5 , comprising:

forming the hole or the projection branch passage with one of the first mold and the second mold.

7. The method of manufacturing the cylinder head cover according to claim 5 , comprising:

setting the main body mold draft direction in an upper direction;

disposing the first mold above the second mold; and

forming the hole or the projection branch passage with the first mold.