Honda Motor Co., Ltd.

F-tech Inc.

Saga Tekkohsho Co., Ltd.

Shosuke Ohhama

Tetsuya Miyahara

Mitsuru Sayama

Tsutomu Kobayashi

Tsunehisa Hata

Daisuke Fukunaga

Tomoyuki Imanishi

Keisuke Tsuta

Kenichi Kawasaki

Akihiko Asami

Hiroyuki Matsufuji

Katsumi Komori

Kazuhiro Sekine

Naoki Osada

A subframe structure includes a frame front part and a frame rear part in a vehicle front-rear direction. The frame front part and the frame rear part are joined together. The frame front part has a higher strength than the frame rear part. The subframe has different strengths from part to part. The frame front part is made of a galvannealed steel plate (GA steel plate) subjected to an electrodeposition coating. The frame rear part is made of a hot-dip galvanized steel plate (GI steel plate) subjected to an electrodeposition coating. A rear cross member of an aluminum die-casting and a rear cross panel of a hot-dip galvanized steel plate (GI steel plate) are integrally joined together by a friction stir welding.

Different materials joint structure

A different materials joint structure includes: a thinned-plate shaped iron member and a thinned-plate shaped aluminum member integrally joined together. The iron member comprises two or more steel thinned plates stacked on each other and an electrodeposition coating is applied to the thinned plates so as to form electrodeposition coating films on surfaces of the thinned plates. The iron member and the aluminum member are then stacked on each other with stacked surfaces, and are joined together by friction stir welding tool inserted from an aluminum member side toward an iron member side in a direction perpendicular to the stacked surfaces.

A joining method for forming a joint structure of different materials includes steps of: providing a steel member and a light metal member stacked on each other and to be joined together by friction stir welding in a non-melted state; applying a coating to the steel member; and joining the steel member and the light metal member together by rotatingly pushing a rotation tool into a joint portion of the light metal member with the steel member, generating friction heat and having the joint portion of the light metal member softened and plastically flow under the friction heat.

Joining method for forming a joint structure of different materials using a peripheral groove

A subframe structure for a front of the vehicle includes a front subframe made of steel and a rear subframe made of a light metal. The front subframe comprises left and right side members extending in approximately parallel with each other and including flange sections, the rear subframe comprises left and right rear side sections including flange sections, and a rear cross section connecting the left and right rear side sections. The left and right rear side sections are stacked on the left and right side members, and the flange section are joined together so as to define left and right closed sections, therebetween, and the left and right side members are further fastened to the left and right rear side sections by bolts extending through the left and right closed sections.

Subframe structure

A different materials joint structure includes: an iron member; an aluminum member disposed on the iron member and integrally joined with the iron member; and a sealant disposed between the iron member and the aluminum member. The aluminum member includes a lateral edge section projecting outwardly from the iron member and extending downwardly, the lateral edge section and a surface of a lateral end of the iron member define a concave section therebetween, and the sealant protruding outwardly from a position between lateral sections of the iron member and the aluminum member is held in the concave section.

A vehicular subframe structure comprises a light alloy member including a left side section and a right side section each extending in a front-rear direction of the vehicle and a cross section extending in a width direction of the vehicle, and a steel plate member including a left thinned plate section and a right thinned plate section each extending in the front-rear direction of the vehicle. When the light alloy member is stacked on the steel plate member they are joined together by friction stir welding from a side of the light alloy member, thereby forming a closed section.

A friction stir welding member is formed by welding a second member to a first member in such a manner that a second member is stacked on a first member, a material property of the second member being different from a material property of the first member, a pin of a welding tool using a Friction Stir Welding technique is inserted into the second member, welding is started at one end of the second member, and the pin is pulled out at a welding terminal portion before the pin reaches the other end of the second member. A projection projecting toward the welding tool is provided integrally with the second member, the projection is formed so as to have a height that is higher than a length of the pin, and the projection is provided with the welding terminal portion.

Friction stir welding member

Friction stir welding is performed in the following manner. In the state in which a probe is rotated in a predetermined rotation direction, the probe is inserted into a flange of a rear sub frame, thereby starting friction stir welding to weld the flange of the rear sub frame and a flange of a front sub frame positioned on the inner side of the rear side of a vehicle. The probe is sequentially moved along the direction of arrow R1&#x2192;arrow R2 (predetermined direction). When the probe reaches the end point of the direction indicated by arrow R2, the probe is inserted into the flange on the outer side across a protruding portion disposed between the flanges. Then, the probe is sequentially moved in the direction of arrow R4&#x2192;arrow R5&#x2192;arrow R6, which is opposite to the direction of arrow R1&#x2192;arrow R2.

Dissimilar-material welded structure and welding method therefor

Disclosed is a subframe for a vehicle that allows a molten metal to be smoothly guided in order to maintain a good flow. This subframe for a vehicle is equipped with a rear subframe. For the rear subframe, a rear cross member, a rear section of a left side member, and a rear upper section of a right side member are constructed with an aluminum alloy and formed into one piece that has a substantially U-shape in a plan view. The rear cross member has a radial rib group that extends radially and a parallel rib group that intersects with the radial rib group. The radial rib group is configured such that radial ribs positioned further outside in the vehicle width direction form larger tilt angles.

Subframe for vehicle

Extending portions of a front sub-frame are each formed by stacking two thin plates made of steel, and flange portions of the front sub-frame and flange portions of a rear sub-frame made of aluminum are superimposed on each other, and are friction stir welded, with a seal material applied to the superimposed surfaces. Of the two thin plates, the thin plate joined to the rear sub-frame made of aluminum has, at each end thereof, a bent portion and an extending part. The bent portion is formed by bending. The end of the extending part extends outward farther than the rear sub-frame. The extending part is covered by the seal material. The bent portion is disposed at a farther end of the extending part.

Different material welded structure

The present invention comprises: a front subframe consisting of steel and divided in the front-rear direction of the vehicle; and a rear subframe consisting of light metal such as an aluminum alloy. The front subframe comprises a press-formed body formed by pressing. The rear subframe comprises a die-cast body formed by die-casting. The front subframe and the rear subframe are joined together by friction stir welding while the left and right rear side sections of the rear subframe are superposed on the upper surfaces of the thin plate sections of the front subframe.

A flange of a left rear side portion (aluminum member) includes a plane section extending toward a vertical wall of a left side member (steel plate-like member). The left side member includes a bent portion formed as a result of being bent between a flange and the vertical wall of the left side member, and a base section, which serves as a start point at which the bent section starts to be bent from the flange of the left side member. The plane section of the left rear side portion is provided such that it covers an area substantially up to the base section of the left side member.

Vehicle structure

Disclosed is a friction stir welding tool () equipped with a probe () and a holder (). At the tip of the probe () there is a pin part () and at the base there are probe-side protrusions () and probe-side recesses (). At the tip of the holder () there are holder-side recesses () which mate with the probe-side protrusions (), and holder-side protrusions () which mate with the probe-side recesses (). External force applied to the probe () is transmitted from the probe-side protrusions () to the holder-side recesses () and from the probe-side recesses () to the holder-side protrusions ().

Friction stir welding tool

Disclosed is a friction-stir joining method for joining a first member, having a base metal covered with a substance different from the base metal, with a second member with the second member placed on the first member by moving a joining tool along a joining line having thereon a joining start point and a joining finish point. The method includes steps of: inserting the joining tool into the second member at the joining start point; moving the joining tool a predetermined distance along the joining line in a direction opposite the joining finish point; causing the joining tool to turn back at a turning-back point spaced the predetermined distance from the joining start point; moving the joining tool along the joining line to the joining finish point past the joining start point; and pulling the joining tool out from the second member at the joining finish point.

Friction-stir joining method

In a structure for mounting a subframe, located under a vehicle body, to the vehicle body via an elastic assembly, the elastic assembly includes: a first mounting member located under the vehicle body and over the subframe; a second mounting member located immediately above the first mounting member; and an elastic member disposed between the first and second mounting members. The first mounting member is mounted to the vehicle body, while the second mounting member is mounted to the subframe.

Growing community of inventors

Wako, Japan

Shosuke Ohhama