Air-conditioning duct in passenger car and railcar

1. An air-conditioning duct in a passenger car of transportation that extends in a passenger car longitudinal direction at a ceiling portion of the passenger car, the air-conditioning duct comprising:

a main duct positioned in a substantially center portion in a passenger car width direction and configured to receive conditioned air from first and second air-conditioning apparatuses located at opposed longitudinal ends of the passenger car;

a chamber duct, positioned adjacent to the main duct in the passenger car width direction, and configured to receive air from the main duct and discharge the conditioned air into an inside of the passenger car; and

a branch duct configured to discharge the conditioned air into the inside of the passenger car and positioned, in the passenger car longitudinal direction, at at least one of the ends of the passenger car with respect to the chamber duct, wherein:

the main duct has a partitioning plate extending in the passenger car longitudinal direction and connecting diagonal positions at both ends of the main duct in the passenger car longitudinal direction so that the partitioning plate divides the main duct into a first chamber and a second chamber,

the branch duct has, arranged in the passenger car width direction at one of the ends of the passenger car, (i) a first rear branch duct configured to receive the conditioned air from the first air-conditioning apparatus through the first chamber and (ii) a second front branch duct configured to receive the conditioned air from the second air-conditioning apparatus through the second chamber,

a discharge volume of the conditioned air discharged from the second front branch duct into the inside of the passenger car is higher than a discharge volume of the conditioned air discharged from the first rear branch duct into the inside of the passenger car, and

a discharge volume of the conditioned air discharged from the chamber duct into the inside of the passenger car is higher than a discharge volume of the conditioned air discharged from the branch duct into the inside of the passenger car.

2. The air-conditioning duct in a passenger car according to claim 1 , wherein the first rear branch duct and the second front branch duct discharge, into the inside of the passenger car at the one end of the passenger car, the conditioned air at 70% to 95% of a uniform airflow volume at which the conditioned air would be uniformly discharged into the inside of the passenger car in the passenger car longitudinal direction.

3. The air-conditioning duct in a passenger car according to claim 1 , further comprising a second front guide plate provided in the second chamber and configured to direct a part of the conditioned air discharged from the second air-conditioning apparatus into the second front branch duct,

wherein the second front guide plate projects from the second front branch duct into the main duct and covers 35% to 60% of a discharge outlet in the passenger car width direction, the discharge outlet being configured to discharge the conditioned air from the second air-conditioning apparatus into the main duct.

4. The air-conditioning duct in a passenger car according to claim 1 , further comprising a second front guide plate provided in the second chamber and configured to direct a part of the conditioned air discharged from the second air-conditioning apparatus into the second front branch duct,

wherein the second front guide plate projects from the second front branch duct into the main duct and covers 35% to 60% of a discharge outlet in a passenger car height direction, the discharge outlet being configured to discharge the conditioned air from the second air-conditioning apparatus into the main duct.

5. The air-conditioning duct in a passenger car according to claim 1 , wherein:

the chamber duct has (i) a first chamber duct arranged on one of right and left sides of the main duct in the passenger car width direction and configured to receive the conditioned air from the first chamber, and (ii) a second chamber duct arranged on the other of the right and left sides of the main duct in the passenger car width direction and configured to receive the conditioned air from the second chamber,

the branch duct has a first front branch duct, both the first front branch duct and the first rear branch duct being configured to receive the conditioned air from the first air-conditioning apparatus through the first chamber,

the branch duct has a second rear branch duct, both the second front branch duct and the second rear branch duct being configured to receive the conditioned air from the second air-conditioning apparatus through the second chamber, and

a discharge volume of the conditioned air discharged from each of the first and second front branch ducts into the inside of the passenger car is higher than a discharge volume of the conditioned air discharged from each of the first and second rear branch ducts into the inside of the passenger car.

6. The air-conditioning duct in a passenger car according to claim 5 , further comprising:

a first front guide plate provided in the first chamber and configured to direct a part of the conditioned air discharged from the first air-conditioning apparatus into the first front branch duct; and

a second front guide plate provided in the second chamber and configured to direct a part of the conditioned air discharged from the second air-conditioning apparatus into the second front branch duct,

wherein each of the first and second front guide plates projects from its respective front branch duct into the main duct and covers 35% to 60% of a respective discharge outlet in the passenger car width direction, each of the respective discharge outlets being configured to discharge the conditioned air from one of the air-conditioning apparatuses into the main duct.

7. The air-conditioning duct in a passenger car according to claim 5 , further comprising:

a first front guide plate provided in the first chamber and configured to direct a part of the conditioned air discharged from the first air-conditioning apparatus into the first front branch duct; and

a second front guide plate provided in the second chamber and configured to direct a part of the conditioned air discharged from the second air-conditioning apparatus into the second front branch duct,

wherein each of the first and second front guide plates projects from its respective front branch duct into the main duct and covers 35% to 60% of a respective discharge outlet in a passenger car height direction, each of the respective discharge outlets being configured to discharge the conditioned air from one of the air-conditioning apparatuses into the main duct.

8. The air-conditioning duct in a passenger car according to claim 1 , further comprising a plug (i) provided in a position corresponding to a suction outlet which is included in a said air-conditioning apparatus and is configured to take in the air in the inside of the passenger car, and (ii) configured to block the discharge of the conditioned air into the inside of the passenger car,

wherein a length in the passenger car longitudinal direction of the plug is equal to or more than a length in the passenger car longitudinal direction of the suction outlet.

9. The air-conditioning duct in a passenger car according to claim 8 , wherein:

the chamber duct has (i) a first chamber duct arranged on one of right and left sides of the main duct in the passenger car width direction and configured to receive the conditioned air from the first chamber, and (ii) a second chamber duct arranged on the other of the right and left sides of the main duct in the passenger car width direction and configured to receive the conditioned air from the second chamber,

the branch duct has a first front branch duct, both the first front branch duct and the first rear branch duct being configured to receive the conditioned air from the first air-conditioning apparatus through the first chamber,

the branch duct has a second rear branch duct, both the second front branch duct and the second rear branch duct being configured to receive the conditioned air from the second air-conditioning apparatus through the second chamber, and

the plug is provided on at least one discharge outlet of each of the first and second front branch ducts and each of the first and second rear branch ducts.

10. The air-conditioning duct in a passenger car according to 8 , wherein the length of the plug is equal to or more than 100% of the length of the suction outlet in the passenger car longitudinal direction and is equal to or less than 160% of the length of the suction outlet in the passenger car longitudinal direction.

11. The air-conditioning duct in a passenger car according to claim 9 , wherein the plug extends to at least one of front and rear sides of the suction outlet in the passenger car longitudinal direction.

12. The air-conditioning duct in a passenger car according to claim 1 , wherein the chamber duct further includes:

a diffuser having an inner side discharge outlet and an outer side discharge outlet arranged in the passenger car width direction, the diffuser being configured to guide the conditioned air from the chamber duct into the inside of the passenger car through the inner side discharge outlet and the outer side discharge outlet; and

an airflow volume adjusting member provided in the chamber duct and configured to balance a discharge volume of the conditioned air from the outer side discharge outlet into the inside of the passenger car with a discharge volume of the conditioned air from the inner side discharge outlet into the inside of the passenger car.

13. The air-conditioning duct in a passenger car according to claim 12 , wherein a percentage of the discharge volume of the conditioned air from the outer side discharge outlet into the inside of the passenger car and the discharge volume of the conditioned air from the inner side discharge outlet into the inside of the passenger car is between 45% and 55%.

14. The air-conditioning duct in a passenger car according to claim 12 , wherein the airflow volume adjusting member is a plate which extends from an upper surface of the chamber duct to a position which is 50% to 65% of the height of the chamber duct in a passenger car height direction.

15. The air-conditioning duct in a passenger car according to claim 12 , wherein the airflow volume adjusting member is installed downstream of the conditioned air in the chamber duct at a position which is 20% or less of the width of the chamber duct from an inlet opening in the chamber duct communicated with the inner side discharge outlet in the passenger car width direction.

16. The air-conditioning duct in a passenger car according to claim 12 , wherein the airflow volume adjusting member is provided at an inlet opening communicated with the outer side discharge outlet of the diffuser in the chamber duct.

17. The air-conditioning duct in a passenger car according to claim 16 , wherein the airflow volume adjusting member is a porous plate or a closing plate.

18. A railcar comprising:

an air-conditioning duct in a passenger car according to claim 1 ; and

an air-conditioning apparatus arranged on a roof of the railcar and configured to supply conditioned air into the air-conditioning duct.

19. A railcar comprising:

an air-conditioning duct in a passenger car according to claim 5 ;

wherein the first air-conditioning apparatus is provided between a first front branch duct and a second rear branch duct in the railcar width direction,

the second air-conditioning apparatus is provided between the first rear branch duct and the second front branch duct in the railcar width direction, and

the main duct is provided between the first air-conditioning apparatus and the second air-conditioning apparatus in the railcar longitudinal direction.

20. The air-conditioning duct in a passenger car according to claim 1 ,

wherein the main duct, the chamber duct, and the branch duct are intersected by a single plane.

21. The air-conditioning duct in a passenger car according to claim 1 , wherein:

the first rear branch duct receives the conditioned air from the first air-conditioning apparatus by way of a rear outlet formed in a side surface of the main duct that faces the passenger car width direction; and

the second front branch duct receives the conditioned air from the second air-conditioning apparatus by way of a front outlet formed in another side surface of the main duct that faces the passenger car width direction.

22. The air-conditioning duct in a passenger car according to claim 1 , wherein:

the first air-conditioning apparatus supplies conditioned air only to a first side of the branch duct in the passenger car width direction; and

the second air-conditioning apparatus supplies conditioned air only to a second side of the branch duct that is opposite the first side in the passenger car width direction.

23. The air-conditioning duct in a passenger car according to claim 1 ,

wherein in the passenger car longitudinal direction, the partitioning plate extends past an outlet in a side surface of the main duct by which the first rear branch duct receives the conditioned air from the first air-conditioning apparatus.

24. The air-conditioning duct in a passenger car according to claim 1 , wherein the branch duct extends from the main duct and toward the longitudinal end of the car so that the second air-conditioning apparatus is between the first rear branch duct and the second front branch duct.

25. The air-conditioning duct in a passenger car according to claim 1 , wherein:

the first rear branch duct receives the conditioned air from the first air-conditioning apparatus by way of a rear outlet formed in a side surface of the main duct that faces the passenger car width direction;

the second front branch duct receives the conditioned air from the second air-conditioning apparatus by way of a front outlet formed in another side surface of the main duct that faces the passenger car width direction;

the first air-conditioning apparatus supplies conditioned air only to a first side of the branch duct in the passenger car width direction;

the second air-conditioning apparatus supplies conditioned air only to a second side of the branch duct that is opposite the first side in the passenger car width direction; and

in the passenger car longitudinal direction, the partitioning plate extends past the rear outlet in the side surface of the main duct by which the first rear branch duct receives the conditioned air from the first air-conditioning apparatus.