Movable vacuum welding device

1. A movable vacuum welding device comprising:

a vacuum chamber having an edge section opposite to a surface of a welding target and forming a vacuum space between the surface of the welding target and the vacuum chamber;

a seal section interposed between the edge section and the welding target throughout the entire circumference of the edge section;

a welding head configured to perform welding on the surface of the welding target in the vacuum space;

a moving unit configured to move the welding target with respect to the vacuum chamber; and

a preload unit configured to previously apply a load to the seal section,

wherein the welding target is moved and the vacuum chamber is stationary so that the welding target moves with respect to the vacuum chamber,

wherein the seal section includes:

a first seal member formed of an elastic material and extending along the edge section; and

a second seal member disposed at least a rear side in the relative moving direction in which a welding bead passes, and having higher flexibility than the first seal member, and

wherein a plurality of elastic members configured to bias the second seal member toward the welding target are provided between the edge section and the second seal member in an extending direction of the second seal member.

2. The movable vacuum welding device according to claim 1 , wherein a concave section corresponding to a shape of the welding bead is formed immediately over the welding bead on a surface of the edge section facing the second seal member.

3. The movable vacuum welding device according to claim 1 , wherein a modulus of elasticity of the elastic member disposed immediately over the welding bead is reduced.

4. The movable vacuum welding device according to claim 1 , wherein the second seal member is a gland packing having a heat-resisting property.

5. A movable vacuum welding device comprising:

a vacuum chamber having an edge section opposite to a surface of a welding target and forming a vacuum space between the surface of the welding target and the vacuum chamber;

a seal section interposed between the edge section and the welding target throughout the entire circumference of the edge section;

a welding head configured to perform welding on the surface of the welding target in the vacuum space;

a moving unit configured to move the welding target with respect to the vacuum chamber; and

a preload unit configured to previously apply a load to the seal section,

wherein the welding target is moved and the vacuum chamber is stationary so that the welding target moves with respect to the vacuum chamber,

wherein the seal section includes:

a first seal member formed of an elastic material and extending along the edge section; and

a second seal member disposed at least a rear side in the relative moving direction in which a welding bead passes, and having higher flexibility than the first seal member, and

wherein the welding head and the vacuum chamber are connected via a movable sealing unit configured to movably support the welding head in a direction perpendicular to the surface of the welding target, and seal a space between the welding head and the vacuum chamber.

6. The movable vacuum welding device according to claim 5 , wherein the movable sealing unit is a bellows formed of a metal.

7. The movable vacuum welding device according to claim 5 , wherein the welding head is supported by a guide section configured to constantly maintain a distance between the welding head and the welding target with respect to the welding target.

8. The movable vacuum welding device according to claim 2 , wherein a modulus of elasticity of the elastic member disposed immediately over the welding bead is reduced.

9. The movable vacuum welding device according to claim 1 , wherein the second seal member is a gland packing having a heat-resisting property.

10. The movable vacuum welding device according to claim 2 , wherein the second seal member is a gland packing having a heat-resisting property.

11. The movable vacuum welding device according to claim 3 , wherein the second seal member is a gland packing having a heat-resisting property.

12. The movable vacuum welding device according to claim 1 , wherein the welding head and the vacuum chamber are connected via a movable sealing unit configured to movably support the welding head in a direction perpendicular to the surface of the welding target, and seal a space between the welding head and the vacuum chamber.

13. The movable vacuum welding device according to claim 2 , wherein the welding head and the vacuum chamber are connected via a movable sealing unit configured to movably support the welding head in a direction perpendicular to the surface of the welding target, and seal a space between the welding head and the vacuum chamber.

14. The movable vacuum welding device according to claim 3 , wherein the welding head and the vacuum chamber are connected via a movable sealing unit configured to movably support the welding head in a direction perpendicular to the surface of the welding target, and seal a space between the welding head and the vacuum chamber.

15. The movable vacuum welding device according to claim 4 , wherein the welding head and the vacuum chamber are connected via a movable sealing unit configured to movably support the welding head in a direction perpendicular to the surface of the welding target, and seal a space between the welding head and the vacuum chamber.

16. The movable vacuum welding device according to claim 6 , wherein the welding head is supported by a guide section configured to constantly maintain a distance between the welding head and the welding target with respect to the welding target.