Bonding structures for containers and method of bonding same

Abstract

A bonding structure for a container member is disclosed. The container member has an opening and a covering member for covering the opening. The container member and covering member are abutted with each other and bonded by a friction stir welding operation. The bonding structure for the container and covering members comprises a bonding portion and a backing member. The bonding portion of the container member and the covering member is formed by inserting a friction stir welding tool into an abutting portion of the container member and the covering member. The backing member is provided for obstructing a plastic flow of materials for the container member and the covering member when the friction stir welding operation is performed. The backing member is disposed adjacent to the bonding portion, at a side of the abutting portion that is opposite to an inserting side of the friction stir welding tool.

1. A bonding structure for a container including a container member having an opening and a covering member for covering the opening of the container member, the bonding structure comprising:
 a bonding portion of the container member and the covering member formed by inserting a friction stir welding tool into an abutting portion of the container member and the covering member and performing a friction stir welding operation; and 
 a backing member that is disposed within a spacing portion that is defined between and enclosed by the bonding portion, the container member and the covering member, wherein the backing member includes a first surface and an opposing second surface, the first surface is disposed adjacent to the bonding portion, at a side of the abutting portion that is opposite to an inserting side of the friction stir welding tool to obstruct a plastic flow of materials of the container member and the covering member when the friction stir welding operation is performed, and the opposing second surface is in contact with a flange portion of one of the container member and the covering member in the spacing portion. 
 
     
     
       2. The bonding structure for the container of  claim 1 , wherein the backing member is substantially rectangular, such that the first surface and the second surface are generally flat, the spacing portion is shaped complementary to the backing member, and wherein the plastic flow of the materials is obstructed by the first surface of the backing member. 
     
     
       3. The bonding structure for the container of  claim 2 , wherein the bonding portion includes a first substantially planar wall surface of the container member and a second substantially planar wall surface of the cover member, wherein the first substantially planar wall surface and the second substantially planar wall surface are opposite to the inserting side of the friction stir welding tool, are substantially coplanar with respect to each other, and are both in engagement with the first surface of the backing member. 
     
     
       4. The bonding structure for the container of  claim 1 , wherein the container member further comprises a groove into which the backing member is inserted, the groove formed by a third substantially planar wall surface of the flange portion and a first substantially planar wall surface of the abutting portion that is parallel to and spaced from the third substantially planar wall surface, and wherein the covering member has a generally convex portion for preventing the backing member from escaping the groove, the generally convex portion spaced apart from the abutting portion and extending toward the flange portion. 
     
     
       5. The bonding structure for the container of  claim 4 , wherein the backing member is constructed of a material that has a softening temperature that is higher than a softening temperature of one or more materials from which the container member and the covering member are constructed. 
     
     
       6. A bonding structure for a torque converter case including an impeller shell having an opening and a converter cover for covering the opening of the impeller shell, the bonding structure comprising:
 a bonding portion of the impeller shell and the converter cover formed by inserting a friction stir welding tool into an abutting portion of the impeller shell and the converter cover and performing a first stir welding operation; and 
 a backing member that is disposed within a spacing portion that is defined between and enclosed by the bonding portion, the impeller shell and the converter cover, wherein the backing member includes a first surface and an opposing second surface, the first surface is in contact with the bonding portion, at a side of the abutting portion that is at a side opposite to an inserting side of the friction stir welding tool to obstruct a plastic flow of materials of the container member and the covering member when the friction stir welding operation is performed, and the opposing second surface is in contact with a flange portion of one of the impeller shell and the converter cover in the spacing portion. 
 
     
     
       7. The bonding structure for the torque converter case of  claim 6 , wherein the first surface is a generally flat surface, and wherein the plastic flow of the materials is obstructed by the generally flat surface. 
     
     
       8. The bonding structure for the torque converter case of  claim 7 , wherein the second surface of the backing member is supported by the impeller shell. 
     
     
       9. The bonding structure for the torque converter case of  claim 7 , wherein the impeller shell has a groove into which the backing member is inserted, the groove formed by the flange portion and the abutting portion, and wherein the converter cover has a generally convex portion for preventing the backing member from escaping the groove, the generally convex portion spaced apart from the abutting portion and extending toward the flange portion. 
     
     
       10. The bonding structure for the torque converter case of  claim 9 , wherein the backing member has a generally annular shape along the bonding portion and an outer portion in a diametric direction of the generally annular shape is inserted into the groove of the impeller shell, wherein the convex portion of the converter cover has a generally annular shape adjacent and inboard of the backing member, and wherein the impeller shell has a generally concave portion into which the convex portion is fitted such that an outer portion in a diametric direction of the generally annular shape faces the convex portion of the converter cover. 
     
     
       11. The bonding structure for the torque converter case of  claim 9 , wherein the torque converter case receives a lock-up clutch and a sliding contact member is mounted on the impeller shell, wherein a frictional material mounted to the lock-up clutch slidingly contacts the sliding contact member, and wherein an outer portion in a diametric direction of the sliding contact member prevents the backing member from escaping the groove. 
     
     
       12. The bonding structure for the torque converter case of  claim 11 , wherein the sliding contact member further comprises at least one generally convex portion and the converter cover comprises at least one generally concave portion, wherein the convex portion is fitted into the convex portion to secure the sliding contact member to the converter cover. 
     
     
       13. The bonding structure for the torque converter case of  claim 8 , wherein the torque converter case receives a lock-up clutch and a sliding contact member is mounted on the impeller shell, wherein a frictional material mounted to the lock-up clutch slidingly contacts the sliding contact member, and wherein an outer portion of the sliding contact member in a diametric direction of the sliding contact member serves as the backing member. 
     
     
       14. The bonding structure for the torque converter case of  claim 8 , wherein the impeller shell is formed by a casting operation, and wherein the backing member is integrally formed by a cast-in operation with the impeller shell. 
     
     
       15. The bonding structure for the torque converter case of  claim 8 , wherein a bonding portion of the impeller shell and the converter cover is molded by forging, and wherein the backing member is fixed to the impeller shell at the time of the forging. 
     
     
       16. The bonding structure of the torque converter case of  claim 8 , wherein the backing member is constructed of a material that has a softening temperature that is higher than a softening temperature of one or more materials from which the impeller shell and the converter cover are constructed. 
     
     
       17. A method of bonding a container including a container member having an opening and a covering member for covering the opening of the container member, the method comprising:
 abutting a portion of the container member and the covering member with each other to define an abutted portion and a spacing portion that is defined between the container member and the covering member; 
 installing a backing member within the spacing portion that is defined between the container member and the covering member, the backing member having a first surface and a second surface opposite the first surface, wherein a first surface of the backing member is disposed adjacent to the abutted portion at a side opposite of the abutted portion to an inserting side of a friction stir welding tool, and the second surface of the backing member is disposed adjacent to a flange portion of one of the container member and the covering member; and 
 inserting the tool into the abutting portion of the container member and the covering member while rotating the tool and performing a friction stir welding operation to form a bonded portion, the backing member obstructing a plastic flow of materials of the container member and the covering member when the friction stir welding operation is performed wherein the backing member is enclosed within the spacing portion defined by the bonding portion, the container member and the covering member. 
 
     
     
       18. The method according to  claim 17 , wherein the flange portion is formed in the container, an end of the flange portion comprising the portion of the container member defining the abutted portion with the portion of the covering member. 
     
     
       19. The method according to  claim 18 , wherein installing the backing member comprises fixing the second surface of the backing member to the flange portion by a plastic forming operation; and wherein abutting the portion of the container member and the covering member with each other comprises:
 deforming the edge of the flange portion to cover an outer peripheral edge of the backing member and a portion of the first surface of the backing member; and 
 placing the cover member to cover the opening of the covering member such that an outer peripheral edge of the covering member abuts the edge of the flange portion to define the abutted portion. 
 
     
     
       20. The method according to  claim 17 , wherein installing the backing member comprises integrally forming the backing member into the flange in a cast-in operation, the backing member comprising a different material from the one of the container member and the covering member including the flange. 
     
     
       21. The method according to  claim 17 , wherein the container member comprises an impeller shell and the covering member is a converter cover, the impeller shell and the converter cover forming a portion of a torque converter case, the method further comprising:
 mounting the sliding contact member on an internal surface of the impeller shell, wherein an outer peripheral edge of the sliding contact member is sandwiched between the impeller shell and the converter cover facing the backing member.