Power conversion device

1. A power conversion device, comprising:

a power conversion circuit unit that converts direct current into alternating current using a semiconductor switching element;

a heatsink on which the power conversion circuit unit is mounted, and which has a first passage through which a cooling medium is caused to pass, the first passage having a first aperture; and

a frame body that houses the power conversion circuit unit, seals the power conversion circuit unit between the frame body and the heatsink, and has a second passage through which the cooling medium is caused to pass, the second passage forming a second aperture facing the first aperture,

wherein the first passage and the second passage are connected at an interface between the heatsink and the frame body, thereby configuring a cooling passage formed of the first passage and the second passage that are provided to form a series,

the second passage is formed in a U-form,

the second aperture comprises a first aperture portion and a second aperture portion that are opened in the interface,

the cooling medium is introduced into the second passage from the first aperture portion and is ejected from the second aperture portion,

the first passage comprises two passages provided in the heatsink and connected to the first aperture portion and the second aperture portion, respectively, and

both end portions of the cooling passage are provided in the heatsink.

2. The power conversion device according to claim 1 , wherein the cooling passage formed of the first passage and the second passage and has a structure divided partway along.

3. The power conversion device according to claim 2 , wherein the cooling passage is of a structure converged in the heatsink or the frame body.

4. The power conversion device according to claim 1 , wherein the heatsink includes a fin that protrudes into the first passage from a wall surface portion of the first passage on a side on which the power conversion circuit unit is mounted.

5. The power conversion device according to claim 1 , wherein the cooling medium is a liquid.

6. A power conversion device comprising:

a power conversion circuit unit that converts direct current into alternating current using a semiconductor switching element;

a heatsink on which the power conversion circuit unit is mounted, and which has a first passage through which a cooling medium is caused to pass, the first passage having a first aperture; and

a frame body that houses the power conversion circuit unit, seals the power conversion circuit unit between the frame body and the heatsink, and has a second passage through which the cooling medium is caused to pass, the second passage forming a second aperture facing the first aperture,

wherein the first passage and the second passage are connected at an interface between the heatsink and the frame body, thereby configuring a cooling passage formed of the first passage and the second passage that are provided to form a series,

the first passage is formed in a U-form,

the first aperture comprises a first aperture portion and a second aperture portion that are opened in the interface,

the cooling medium is introduced from the first aperture portion and ejected from the second aperture portion,

the second passage comprises two passages provided in the frame body and connected to the first aperture portion and the second aperture portion, respectively, and

both end portions of the cooling passage are provided in the frame body.

7. The power conversion device according to claim 6 , wherein the cooling passage formed of the first passage and the second passage and has a structure divided partway along.

8. The power conversion device according to claim 7 , wherein the cooling passage is of a structure converged in the heatsink or the frame body.

9. The power conversion device according to claim 6 , wherein the heatsink includes a fin that protrudes into the first passage from a wall surface portion of the first passage on a side on which the power conversion circuit unit is mounted.

10. The power conversion device according to claim 6 , wherein the cooling medium is a liquid.

11. A power conversion device comprising:

a power conversion circuit unit that converts direct current into alternating current using a semiconductor switching element;

a heatsink on which the power conversion circuit unit is mounted, and which has a first passage through which a cooling medium is caused to pass; and

a frame body that houses the power conversion circuit unit, seals the power conversion circuit unit between the frame body and the heatsink, and has a second passage through which the cooling medium is caused to pass,

wherein the first passage and the second passage are connected at an interface between the heatsink and the frame body, thereby configuring a cooling passage,

the power conversion circuit unit is sealed between the heatsink and the frame body across a first packing,

the first passage and the second passage are connected at the interface between the heatsink and the frame body across a second packing, and

the first packing and the second packing are integral with each other.

12. The power conversion device according to claim 11 , wherein the cooling passage formed of the first passage and the second passage and has a structure divided partway along.

13. The power conversion device according to claim 12 , wherein the cooling passage is of a structure converged in the heatsink or the frame body.

14. The power conversion device according to claim 11 , wherein the heatsink includes a fin that protrudes into the first passage from a wall surface portion of the first passage on a side on which the power conversion circuit unit is mounted.

15. The power conversion device according to claim 11 , wherein the cooling medium is a liquid.