Friction stir welding method, and hollow shape member for friction stir welding

A hollow shape structure having a first hollow shape member friction stir welded to a second hollow shape member, formed (1) by abutting an end, in a width direction, of the first hollow shape member, to an end, in the width direction, of the second hollow shape member, to provide abutting ends of the first and second hollow shape members, and (2) by friction stir welding the abutting ends, wherein:

• the first hollow shape member, extending in a thickness direction and the width direction, comprises:
• first and second face plates, each having respective end portions extending inward from ends of the first and second face plates in the width direction of the first hollow shape member, each of the first and second face plates having a thickness in the thickness direction of the first hollow shape member,
• a first connecting plate for connecting said first and second face plates, one end of which is connected to a location of one of the first and second face plates other than at an end portion, of the respective end portions, in the width direction of the first hollow shape member,
• a second connecting plate for connecting said respective end portions of said first and second face plates, disposed substantially orthogonal to said first and second face plates,
• recessed portions provided respectively to each connecting portion where said first and second face plates are connected with said second connecting plate, each recessed portion opening outward toward both the width direction and the thickness direction of said first hollow shape member, and
• grooves opening outwardly in the width direction, or projections protruding outwardly in the width direction, formed at said recessed portions, respectively;
• the second hollow shape member, extending in the thickness direction and the width direction, comprises:
• third and fourth face plates, each having respective end portions extending inward from ends of the third and fourth face plates in the width direction of the second hollow shape member, each of the third and fourth face plates having a thickness in the thickness direction of the second hollow shape member,
• a third connecting plate, closest to ends of the third and fourth face plates forming an end of the second hollow shape member, for connecting said third and fourth face plates of the second hollow shape member, one end of said third connecting plate being connected to a location of one of the third and fourth face plates other than said end portion of said one of the third and fourth face plates,
• a projection or groove formed at one face plate, of the third and fourth face plates, at said end portion thereof, and
• a projection or groove formed at the other face plate, of the third and fourth face plates, at said end portion thereof;
• and
• said projections of the first and second hollow shape members are each inserted into a corresponding groove in the other of the first and second hollow shape members, when the ends of the first and second hollow shape members are abutted against each other.

A hollow shape member for friction stir welding, extending in a thickness direction and in a width direction, and capable of being friction stir welded to a second hollow shape member having projections or grooves extending in the width direction, comprising:

• two face plates, each having respective end portions extending inward from ends of the two face plates in the width direction of the hollow shape member, each of the two face plates having a thickness In the thickness direction of the hollow shape member;
• a connecting plate closest to the ends of the two face plates forming an end of the hollow shape member, for connecting said two face plates of the hollow shape member, one end of said connecting plate being connected to a location of one of the two face plates other than said end portion of said one of the two face plates;
• a projection or groove formed to one face plate at said end portion thereof;
• and
• a projection or groove formed to the other face plate at said end portion thereof, wherein said grooves of said hollow shape member are capable of having projections of the second hollow shape member positioned in said grooves, and said projections of said hollow shape member are capable of being positioned in grooves of the second hollow shape member, when the hollow shape member and the second hollow shape member abut each other for the friction stir welding.

A hollow shape member for friction stir welding, extending in a thickness direction and in a width direction, comprising:

• two face plates, each having respective end portions extending inward from ends of the two face plates in the width direction of the hollow shape member, each of the two face plates having a thickness in the thickness direction of the hollow shape member;
• a first connecting plate for connecting said two face plates, one end of which is connected to a location of one of the two face plates other than at an end portion, of the respective end portions, in the width direction of the hollow shape member;
• a second connecting plate for connecting said respective end portions of said two face plates, disposed substantially orthogonal to said face plates;
• recessed portions provided respectively to each connecting portion where said two face plates are connected with said second connecting plate, each recessed portion opening outward toward both the width direction and the thickness direction of said hollow shape member, wherein each connecting portion is provided with a protruding block for supporting another hollow shape member to be friction stir welded to said hollow shape member, during the friction stir welding;
• and
• grooves opening outwardly in the width direction, or projections protruding outwardly in the width direction, formed at said recessed portions, respectively,
• wherein said grooves or said projections are spaced from said protruding block.

A hollow shape member for friction stir welding, extending in a thickness direction and in a width direction, comprising:

• two face plates, each having respective end portions extending inward from ends of the two face plates in the width direction of the hollow shape member, each of the two face plates having a thickness in the thickness direction of the hollow shape member;
• a first connecting plate for connecting said two face plates, one end of which is connected to a location of one of the two face plates other than at an end portion, of the respective end portions, in the width direction of the hollow shape member;
• a second connecting plate for connecting said respective end portions of said two face plates, disposed substantially orthogonal to said face plates;
• recessed portions provided respectively to each connecting portion where said two face plates are connected with said second connecting plate, each recessed portion opening outward toward both the width direction and the thickness direction of said hollow shape member;
• and
• grooves opening outwardly in the width direction, formed at said recessed portions.

A hollow shape member for friction stir welding, extending in a thickness direction and in a width direction, comprising:

• two face plates, each having respective end portions extending inward from ends of the two face plates in the width direction of the hollow shape member, each of the two face plates having a thickness in the thickness direction of the hollow shape member;
• a first connecting plate for connecting said two face plates, one end of which is connected to a location of one of the two face plates other than at an end portion, of the respective end portions, in the width direction of the hollow shape member;
• a second connecting plate for connecting said respective end portions of said two face plates, disposed substantially orthogonal to said face plates;
• recessed portions provided respectively to each connecting portion where said two face plates are connected with said second connecting plate, each recessed portion opening outward toward both the width direction and the thickness direction of said hollow shape member;
• and
• grooves opening outwardly in the width direction, or projections protruding outwardly in the width direction, formed at said recessed portions, respectively,
• wherein said grooves of said hollow shape member extend in the width direction from a boundary edge of the recessed portions, said boundary edge forming a boundary of the recessed portions in the width direction, and wherein said projections protrude outwardly in the width direction within said recessed portions, from said boundary edge.

A hollow shape member for friction stir welding, extending in a thickness direction and in a width direction, comprising:

• two face plates, each having respective end portions extending inward from ends of the two face plates in the width direction of the hollow shape member, each of the two face plates having a thickness in the thickness direction of the hollow shape member;
• a first connecting plate for connecting said two face plates, one end of which is connected to a location of one of the two face plates other than at an end portion, of the respective end portions. In the width direction of the hollow shape member;
• a second connecting plate for connecting said respective end portions of said two face plates, disposed substantially orthogonal to said face plates;
• recessed portions provided respectively to each connecting portion where said two face plates are connected with said second connecting plate, each recessed portion opening outward toward both the width direction and the thickness direction of said hollow shape member;
• and
• grooves opening outwardly in the width direction, formed at said recessed portions, or projections protruding outwardly in the width direction, formed within said recessed portions, respectively.

A hollow shape member for friction stir welding, extending in a thickness direction and In a width direction, comprising:

• two face plates, each having respective end portions extending inward from ends of the two face plates in the width direction of the hollow shape member, each of the two face plates having a thickness in the thickness direction of the hollow shape member;
• a first connecting plate for connecting said two face plates, one end of which is connected to a location of one of the two face plates other than at an end portion, of the respective end portions, in the width direction of the hollow shape member;
• a second connecting plate for connecting said respective end portions of said two face plates, disposed substantially orthogonal to said face plates;
• recessed portions provided respectively to each connecting portion where said two face plates are connected with said second connecting plate, each recessed portion opening outward toward both the width direction and the thickness direction of said hollow shape member;
• and
• projections protruding outwardly in the width direction, formed within said recessed portions.