Core for casting turbine blade, method of manufacturing the core, and turbine blade manufactured using the core

1. A core for casting a turbine blade to form at least one cooling passage in a wing portion of the turbine blade, wherein the wing portion comprises a leading edge region and a trailing edge region, and has a streamlined cross-section, the core comprising:

at least one of a first core unit having a shape corresponding to a cooling passage located at the leading edge region, and a second core unit spaced apart from the first core unit and having a shape corresponding to a cooling passage located at the trailing edge region,

wherein each of the first core unit and the second core unit comprises:

a plurality of extending portions extending in a longitudinal direction and located substantially parallel to one another;

at least one curved portion connecting adjacent ends of the plurality of extending portions; and

at least one through-portion located between the plurality of extending portions and having an empty space extending in a width direction of the wing portion,

wherein the at least one through-portion of the first core unit and the at least one through-portion of the second core unit extend in substantially the same direction along the width direction of the wing portion, and

wherein the first core unit comprises a plurality of through-portions which extend in a longitudinal direction of the wing portion.

2. The core of claim 1 , further comprising:

a third core unit located adjacent to a trailing edge of the second core unit and having a plurality of holes and a plurality of slots; and

an additional through-portion located between the second core unit and the third core unit and having an empty space extending in the width direction of the wing portion.

3. The core of claim 2 , wherein the third core unit is connected to the trailing edge of the second core unit.

4. The core of claim 1 , wherein the plurality of extending portions comprise a first extending portion and a second extending portion located on a leading edge of the first core unit, and

wherein the first core unit comprises a plurality of connecting portions configured to connect the first extending portion with the second extending portion.

5. The core of claim 1 , wherein the at least one through-portion of the first core unit and the at least one through-portion of the second core unit are substantially parallel to each other.

6. The core of claim 1 , wherein at least two of the plurality of through-portions of the first core unit are substantially parallel to each other.

7. The core of claim 1 , wherein the second core unit comprises a plurality of through-portions, and at least two of the plurality of through-portions of the second core unit are substantially parallel to each other.

8. The core of claim 1 , further comprising:

a third core unit located adjacent to a trailing edge of the second core unit, and having a plurality of holes and a plurality of slots; and

an additional through-portion located between the second core unit and the third core unit, and having an empty space extending in the width direction of the wing portion,

wherein the additional through-portion is located substantially parallel to the at least one through-portion of the first core unit.

9. The core of claim 1 , further comprising:

a third core unit located adjacent to a trailing edge of the second core unit, and having a plurality of holes and a plurality of slots; and

an additional through-portion located between the second core unit and the third core unit, and having an empty space extending in the width direction of the wing portion,

wherein the additional through-portion is located substantially parallel to the at least one through-portion of the second core unit.

10. The core of claim 1 , wherein the plurality of extending portions and the at least one curved portion are connected to one another to form an S-shape.

11. The core of claim 1 , wherein edges of the at least one curved portion are chamfered so as to have a curved shape.

12. A method of manufacturing a core for casting a turbine blade to form at least one cooling passage in a wing portion of the turbine blade, wherein the wing portion comprises a leading edge region and a trailing edge region and has a streamlined cross-section, the method comprising:

forming the core of claim 1 by injecting a core forming material into a cavity of a mold; and

separating the core from the mold,

wherein the separating of the core comprises separating the mold in the width direction of the wing portion.

13. A core for casting a turbine blade to form at least one cooling passage in a wing portion of the turbine blade, wherein the wing portion comprises a leading edge region and a trailing edge region, and has a streamlined cross-section, the core comprising:

at least one of a first core unit having a shape corresponding to a cooling passage located at the leading edge region;

a second core unit spaced apart from the first core unit and having a shape corresponding to a cooling passage located at the trailing edge region; and

a third core unit located adjacent to a trailing edge of the second core unit and having a plurality of holes and a plurality of slots,

wherein each of the first core unit and the second core unit comprises:

a plurality of extending portions extending in a longitudinal direction and located substantially parallel to one another;

at least one curved portion connecting adjacent ends of the plurality of extending portions,

at least one through-portion located between the plurality of extending portions and having an empty space extending in a width direction of the wing portion,

wherein the at least one through-portion of the first core unit and the at least one through-portion of the second core unit extend in substantially the same direction along the width direction of the wing portion,

wherein the first core unit comprises a plurality of through-portions,

wherein a portion of the second core unit and a portion of the third core unit are formed together in a first S-shape curve, and

wherein the plurality of extending portions of the first core unit are formed together in a second S-shape curve.