Chain cover
A chain cover is configured to cover a timing chain that transmits rotation of a crankshaft of an internal combustion engine to a camshaft. The chain cover includes a crankshaft-side opening forming portion that defines a crankshaft-side opening into which the crankshaft is inserted, and a general portion that is a section different from the crankshaft-side opening forming portion. The crankshaft-side opening forming portion is made of a first material. The general portion is made of a second material. The first material and the second material are different from each other.
1. A chain cover that is configured to cover a timing chain that transmits rotation of a crankshaft of an internal combustion engine to a camshaft, the chain cover comprising:
a crankshaft-side opening forming portion that defines a crankshaft-side opening into which the crankshaft is inserted; and
a general portion that is a section different from the crankshaft-side opening forming portion, wherein
the crankshaft-side opening forming portion is made of a first material,
the general portion is made of a second material,
the first material and the second material are different from each other,
the chain cover includes a camshaft-side opening into which the camshaft is inserted,
a section of the chain cover that defines the camshaft-side opening is made of a third material, and
the third material is different from both the first material and the second material.
2. The chain cover according to claim 1 , wherein the third material has a lower coefficient of linear expansion than the second material.
3. The chain cover according to claim 1 , wherein the third material has a lower water absorbency than the second material.
4. The chain cover according to claim 1 , wherein at least one of the first material, the second material, and the third material is a plastic material.
5. The chain cover according to claim 1 , comprising fixing portions used to fix the chain cover to the internal combustion engine, wherein
the fixing portions are provided in a region of the chain cover that includes the section defining the camshaft-side opening and is made of the third material, and
the fixing portions are located on opposite sides of the camshaft-side opening.
6. The chain cover according to claim 1 , wherein
the first material is a metal material,
the third material is a first plastic material,
the second material is a second plastic material, and
the first plastic material has a lower coefficient of linear expansion than the second plastic material.
7. The chain cover according to claim 1 , wherein
the first material is a metal material,
the third material is a first plastic material,
the second material is a second plastic material, and
the first plastic material has a lower water absorbency than the second plastic material.