Gas generator and restraining device using same

1. A gas generator, comprising:

a housing having a plurality of groups of gas discharge ports, each gas discharge port being closed from an inside of the housing by a closing member;

an ignition device accommodated inside the housing; and

a gas generating agent ignited and burnt by an activation of the ignition device to generate combustion gas,

wherein the plurality of groups of gas discharge ports includes a first group of gas discharge ports opened at a first pressure and a second group of gas discharge ports opened at a second pressure lower than the first pressure,

the gas generator further comprising:

a cooling member that covers only the first group of gas discharge ports from an outside of the housing without covering the second group of gas discharge ports.

2. The gas generator according to claim 1 , wherein

a diameter of gas discharge ports in the first group is smaller than a diameter of gas discharge ports in the second group,

the first group of gas discharge ports and the second group of gas discharge ports are disposed separately in different areas,

all of the gas discharge ports in the first group and the second group are sealed, from the inside, by the same closing member, and

the gas discharge ports of the second group open at the second pressure, and the gas discharge ports of the first group open at the first pressure.

3. The gas generator according to claim 1 , wherein

a diameter of the gas discharge ports in the first group is the same as a diameter of the gas discharge ports in the second group,

the first group of gas discharge ports and the second group of gas discharge ports are disposed separately in different areas, and

the gas discharge ports of the first group are sealed by a closing member of a maximum strength that opens at the first pressure, and the gas discharge ports of the second group are sealed by a closing member of a minimum strength that opens at the second pressure.

4. The gas generator according to claim 1 , wherein a space is provided between the first group of gas discharge ports and the cooling member.

5. The gas generator according to claim 4 , wherein the cooling member is a metallic plate.

6. The gas generator according to claim 4 , wherein the cooling member is a metallic plate having concaves and convexes on a surface thereof that faces the gas discharge ports of the first group.

7. A restraining device, comprising:

the gas generator according to claim 1 ; and

a module case accommodating the gas generator therein,

wherein the cooling member is attached to the module case.

8. The restraining device according to claim 7 , further comprising:

a fixing member including a central hole for fitting the gas generator therein,

wherein the cooling member is attached to the fixing member along with the gas generator.

9. A gas generator, comprising:

a housing having a plurality of gas discharge ports, each gas discharge port being closed from an inside of the housing by a closing member;

an ignition device accommodated inside the housing; and

a gas generating agent ignited and burnt by an activation of the ignition device to generate combustion gas,

wherein the plurality of discharge ports includes a first gas discharge port opened at a first pressure and a second gas discharge port opened at a second pressure lower than the first pressure,

the gas generator further comprising:

a cooling member that covers only the first gas discharge port from an outside of the housing without covering the second gas discharge port.

10. The gas generator according to claim 9 , wherein

a diameter of the first gas discharge port is smaller than a diameter of the second gas discharge port,

the first gas discharge port and the second gas discharge port are disposed separately in different areas,

the first gas discharge port and the second gas discharge port are sealed, from the inside, by the same closing member, and

the second gas discharge port opens at the second pressure, and the first gas discharge port opens at the first pressure.

11. The gas generator according to claim 9 , wherein

a diameter of the first gas discharge port is the same as a diameter of the second gas discharge port,

the first gas discharge port and the second gas discharge port are disposed separately in different areas, and

the first gas discharge port is sealed by a closing member of a maximum strength that opens at the first pressure, and the second gas discharge port is sealed by a closing member of a minimum strength that opens at the second pressure.

12. The gas generator according to claim 11 , wherein the cooling member is a metallic plate.

13. The gas generator according to claim 11 , wherein the cooling member is a metallic plate having concaves and convexes on a surface thereof that faces the first gas discharge port.

14. The gas generator according to claim 9 , wherein a space is provided between the first gas discharge port and the cooling member.

15. A restraining device, comprising:

the gas generator according to claim 9 ; and

a module case accommodating the gas generator therein,

wherein the cooling member is attached to the module case.

16. The restraining device according to claim 15 , further comprising:

a fixing member including a central hole for fitting the gas generator therein,

wherein the cooling member is attached to the fixing member along with the gas generator.