Kabushiki Kaisha Toyota Chuo Kenkyusho

Toyota Jidosha Kabushiki Kaisha

Hideaki Matsuoka

Tatsuyuki Amago

Manabu Ooga

Shuhei Ogura

Toru Hioki

Takashi Asada

Kyosuke Izuno

Tomohiko Sekiguchi

Koki Nakada

Hiroyuki Mori

Ayaka Kagami

Kenzo Fukumori

Jun Yaokawa

Takashi Goto

Kohei Takahashi

Yuka Yamada

Mikio Kondoh

Kazuhiko Umemoto

Gaku Kitahara

Shun Kato

Shuxin Dong

Tomonori Yanagawa

Takuro Matsunaga

Takanori Nakagaki

Hiroaki Kadoura

Ken-Ichi Suzuki

An electrode tip for resistance spot welding includes a main body with tip and base portions. The tip portion has a bottomed and substantially cylindrical shape. The base portion has a substantially cylindrical shape and merges into the tip portion. The main body is made of a copper alloy such as chromium copper. The tip portion has a bottom part and a barrel part. The bottom part has a pressure-contact surface that is not recessed with respect to a workpiece to be pressed. The barrel part has a substantially cylindrical shape and merges into the bottom part. The electrode tip may have an inner diameter ratio (inner diameter of the barrel part to an outer diameter of the base portion) of 0.4 to 0.6, and may also have a bottom thickness ratio (thickness of the bottom part to the outer diameter of the base portion) of 0.15 to 0.5.

Electrode tip for resistance spot welding

A method of manufacturing a member for fastening by joining a nut with a tubular joint portion extending from a main body formed with an internal thread to a panel with a mounting hole for the nut on an aluminum base material. The joint portion has a rotation-preventing portion with a concave and convex shaped outer peripheral surface and a guide portion extending from the rotation-preventing portion to one side. After the guide portion is inserted into the mounting hole, the nut is energized by electrodes in contact with both nut end surface sides. The nut then generates heat, and the periphery of the mounting hole is heated and softened. When the nut is pressurized with the electrodes, the rotation-preventing portion bites into the mounting hole, and the one end portion of the guide portion is swaged to become a retaining portion on one surface side of the panel.

Member for fastening and method of manufacturing same

A spot welding method includes a heating step of energizing an electrode in pressure contact with an Al alloy member to heat and melt a join part by resistance heating and a cooling step of cooling the join part after the heating step in a state in which the electrode is in pressure contact with the Al alloy member. The alloy is a wrought alloy of Mg: 0.2 to 1.2 mass %, Si: 0.4 to 1.5%, and Cu: 1.1% or less or a casting alloy of Si: 7 to 11% and Mg: 0.1 to 0.4% with respect to 100% as a whole. The cooling step includes a first cooling process performed with a reduced amount of input energy to the join part as compared with the heating step and a second cooling process performed after the first cooling process at a higher cooling rate than that in the first cooling process.

Spot welding method

A novel spot welding method for steel sheets and an aluminum alloy sheet, includes stacked sheet materials from a pair of opposing electrodes to join the sheet materials by resistance heating. The pair of opposing electrodes are in pressure contact with both outer surfaces of the sheet sets. The sheet sets include at least a first and second steel sheet, and an aluminum alloy sheet stacked in this order. A first energization step forms a molten pool between facing surfaces of the first and second steel sheets without melting the aluminum alloy sheet. A second energization step causes a melting reaction between facing surfaces of the second steel sheet and the aluminum alloy sheet. The first and second steel sheets are joined via a first nugget. The second steel sheet and the aluminum alloy sheet are joined via a second nugget including an intermetallic compound generated by the melting reaction.

An electrode tip portion is provided with a projection portion and a plurality of recess portions. The plurality of the recess portions are independent of one another, and are provided at the electrode tip portion in a dispersed manner. The projection portion is a region other than regions where the recess portions are provided, and is configured to be equipped with a continuous surface that continues in regions among the plurality of the recess portions.

Electrode for resistance spot welding

A highly corrosion-resistant spot weldment can be produced at low cost without occurrence of prominent protrusions and the like on the surface. The spot weldment is joined by a nugget formed inside stacked sheet materials through bringing a pair of electrodes arranged opposite to each other into pressure contact with the stacked sheet materials from outside and energizing the stacked sheet materials from the electrodes. The nugget has a diameter that is &#x2265;4&#x221a;t (t: thickness of sheet material) and a flattening level of 3.5 to 8, which is a ratio of diameter to thickness. Both outer surface parts of the sheet materials are free from protrusions formed due to bulging of molten metal. Even when the electrodes are made of a copper alloy, the increased amount of Cu in the outer surface parts is 0.2 mass % or less with respect to the component composition before spot welding.

Spot weldment

A metal-resin composite material including an aluminum substrate having an aluminum oxide coating and a resin bonded to the aluminum substrate through the aluminum oxide coating, wherein the aluminum oxide coating has a porous surface layer in which columns with an average height of 10 to 100 nm are arranged in a dispersed state, an average value of sums of cross-sectional areas of the columns in randomly sampled 400 nm square visual fields of the porous surface layer is 8000 to 128000 nm, an average value of sums of circumferential lengths of cross-sections of the columns in randomly sampled 400 nm square visual fields of the porous surface layer is 1000 to 27000 nm, and an average value of numbers of the columns in randomly sampled 400 nm square visual fields of the porous surface layer is 10 to 430.

Metal-resin composite material, method for producing the same, and aluminum substrate having aluminum oxide coating

A casted aluminum alloy obtained by casting a molten metal of an aluminum alloy, an aluminum alloy material obtained by at least heating the casted aluminum alloy, and methods for producing them. In the production of the casted aluminum alloy, a molten metal is obtained by melting an aluminum alloy containing 0.8 to 5 mass % of Fe, 0.15 to 1 mass % of Ti, Zr or the like as third component elements in an specific amount, and a residual part containing Al and inevitable impurities at a certain temperature (melting step). Subsequently, the molten metal is cast into a plate-like shape by a casting mold while cooling the molten metal to a temperature that is lower by at least 10&#xb0; C. than a solidus temperature of the aluminum alloy at a cooling rate of 150&#xb0; C./sec. or more and less than 10000&#xb0; C./sec. (casting step).

Casted aluminum alloy and method for producing the same as well as aluminum alloy material and method for producing the same

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Nagakute, Japan

Hideaki Matsuoka