Nippon Steel Corporation

Toshiba Tec Kabushiki Kaisha

Nippon Steel & Sumitomo Metal Corporation

Tohru Okada

Seiji Furusako

Fuminori Watanabe

Keiichi Hasegawa

Yasunobu Miyazaki

Masanori Yasuyama

Yasuhiro Arai

Naoki Nishiyama

Yoshiaki Nakazawa

Hiroki Fujimoto

Koichi Sato

Takashi Imamura

Chisato Yoshinaga

Yasuhiro Ito

Hiroyuki Kawata

Koichi Hamada

Satoshi Hirose

Chisato Wakabayashi

Hideki Hamatani

Hideki Ueda

Yasunori Sawa

Kazuhiko Fukutani

Hitomi Nishibata

Tasuku Zeniya

Gen Murayama

Teruki Sakamoto

A welded joint manufacturing method includes: abutting a first electrode against a first steel sheet of a welded joint at a site A, which is a location at an outer side of a nugget in a sheet-plane direction in a plane running parallel to the first steel sheet; abutting a second electrode against a second steel sheet at a site B, which is a location at an outer side of the nugget in a sheet-plane direction in a plane running parallel to the first steel sheet of the welded joint, and positioned on an opposite side of the nugget from the site A; and passing a current through the welded joint between the first electrode and the second electrode.

Welded joint manufacturing method, welded joint, tempering device, and welding apparatus

There is provided a resistance spot welding apparatus including a first rod-shaped electrode body, second rod-shaped electrode body, first ring-shaped member, second ring-shaped member, first elastic body, and second elastic body. The first rod-shaped electrode body and second rod-shaped electrode body are arranged facing each other, the first rod-shaped electrode body is inserted into a through hole of the first ring-shaped member, the first elastic body is connected to an opposite side of first ring-shaped member to second rod-shaped electrode body side, the first rod-shaped electrode body and first ring-shaped member are not electrically connected to each other, the second rod-shaped electrode body is inserted into a through hole of the second ring-shaped member, the second elastic body is connected to an opposite side of second ring-shaped member to first rod-shaped electrode body side, and the second rod-shaped electrode body and second ring-shaped member are not electrically connected each other.

Resistance spot welding apparatus and method for manufacturing a welded structure

A structural member is provided that includes a steel sheet with a tensile strength of 980 MPa or higher overlying another metal plate and joined thereto by welding, where a break initiating near a welded portion is less likely to be produced. A structural member () includes: a first member (), the first member being a steel sheet with a tensile strength of 980 MPa or higher; a second member () overlying the first plate (), the second member being a metal plate; a plurality of welded portions (); a plurality of heat-affected zones () each formed to surround the corresponding one of the welded portions (), the heat-affected zones having a Vickers hardness lower than that of the first member by 50 HV or more. A pair of edge sections () of the first member () are provided between adjacent heat-affected zones (). The pair of edge sections () of the first member located between the adjacent heat-affected zones () extend to cross a line (LC) linking the adjacent welded portions ().

Structural member

A networked computer system distributes content that is to be added to receipts by receipt issuing devices. The system includes a central server, first and second store servers communicating with the central server over a first network, first receipt issuing devices communicating with the first store server over a first local network, and second receipt issuing devices communicating with the second store server over a second local network. A first control plane is implemented in the central server to control whether or not the content is to be distributed to the first store server and whether or not the content is to be distributed to the second store server. A second control plane is implemented in the first and second store servers to control whether or not the content is to be distributed to the first and second receipt issuing devices, respectively.

Content distribution system

By obtaining a spot-welded joint being a spot-welded joint formed by overlapping a plurality of pieces of steel plates (A,B) and performing spot welding on the steel plates, including a high-strength steel plate whose tensile strength is 750 (MPa) to 2500 (MPa), being at least one piece of steel plate out of the plurality of pieces of steel plates, in which a carbon equivalent Ceq of the high-strength steel plate is 0.20 mass % to 0.55 mass %, and ten or more of iron-based carbides in each of which a length of a longest portion is 0.1 (&#x3bc;m) or more exist in a square regionwithin a heat-affected zoneof a cross section that passes through a center of a welding mark, and is cut along a plate thickness direction of the steel plates (A,B), a cross tensile strength of the spot-welded joint to be formed is improved.

Spot-welded joint and spot welding method

A spot welded joint in which a high CTS is obtained even if including one or more high strength steel sheets and a method of welding of the same, that is, a spot welded jointincluding a plurality of steel sheets, wherein one or more steel sheets is a tensile strength 750 to 2500 MPa high strength steel sheet and, at a cross-section in the sheet thickness direction of the steel sheets, when defining superposed surfaces of a high strength steel sheet Sarranged at an outermost side and another steel sheetB as the 'plane A' and defining a plane passing through a point of one-half of a distance between a nugget end position E of a high strength steel sheet Sside on the line Lin the sheet thickness direction and a crossing point O of the plane A and the line Land parallel to the plane A as the 'plane B', at a square area SA of sides of 30 &#x3bc;m centered about a crossing point X of a line L, which is separated by 250 &#x3bc;m to the heat affected zone side from a tangent at any position on a nugget end line NEL sandwiched between the plane A and plane B and parallel to that tangent, and a line Lvertical to Lincluded in a heat affected zonehaving a high strength steel sheet Sas a base material, an average value of widths of the blocks formed from lath martensite is 0.5 to 7.0 &#x3bc;m.

Spot welded joint and spot welding method

Provided is a spot welding machine able to perform spot welding in which the desired nugget size is formed while suppressing spatter even if the strengths or thicknesses of the metal sheets change, the machine comprising: a pair of electrode tips, a pair of pressing members arranged around the tips, a first power supply, first and second drive mechanisms, and a pressing force control part, wherein the tips and the pressing members are respectively arranged facing each other so as to be able to sandwich a set of sheets between them, the first drive mechanisms give pressing forces pressing the tips against the sheets, the second drive mechanisms give pressing forces pressing the pressing members against the sheets, and the control part independently controls the pressing forces given by the first and second drive mechanisms.

Spot welding electrode having movable pressing members and spot welding method using same

A lap welding method of a steel sheet includes spot welding in a state in which the flange portion of a second steel sheet member having the flange portion and a standing wall portion is overlapped with the first steel sheet member, thereby forming a nugget between a first steel sheet member and a flange portion; and, after the spot welding, laser welding a region between an R stop of the standing wall portion and the nugget, thereby forming a weld bead, and, in the weld bead, a length dimension is equal to or longer than a diameter of the nugget, and a width dimension is 0.5 to 3.0 mm.

Lap welding method of steel sheet and lap weld joint of steel sheet

Provided is a mechanical joining apparatus enabling stable riveting when joining metal sheets even when the sheets are large in deformation resistance, the apparatus comprising a punch and die, blank holder and power device, wherein the punch and die are arranged facing each other, the holder is configured by an electrode material able to push against and electrically heat the sheets by one end of the holder, the punch is comprised of a material able to drive in a rivet, the die is comprised of an electrode material able to support and electrically heat the sheets, and the power device is configured to start supply of current through the holder and die so as to raise the temperature of the sheets at the same time as the start of driving in of the rivet and to continue to supply current until the end of driving in of the rivet.

Mechanical joining apparatus and mechanical joining method

A spot welding electrode of a donut-shaped electrode wherein even when a welded member of a steel sheet is slanted with respect a plane perpendicular to an axis of the spot welding electrode, a cross tensile strength (CTS) of the spot welded joint can be improved. The donut shape spot welding electrode according to the present invention has an electrode tip and an electrode support. The electrode tip contacts the electrode support to be able to move. Due to this, it is possible to strikingly raise the ability of the donut-shaped electrode to track a steel sheet and make the entire surface of the donut shape contact-and-conduction part contact the steel sheet, so it is possible to secure a high CTS value even if the steel sheet is slanted.

Spot welding electrode and welding apparatus and welding method using same

Provided is a mechanical joining apparatus enabling reduction of breakage of the area around a rivet of a joint obtained by riveting, the apparatus comprising a punch and die, blank holder, first power device, second power device and cooling device, wherein the first power device is configured to start supply of current through the holder and die so as to raise the temperature of the sheets before the punch drives in the rivet, the second power device is configured to start supply of current through the punch and die so as to supply current through and heat treat the rivet after the punch drives in the rivet, and the cooling device is connected to the punch and is configured to cool the rivet after the rivet is heat treated.

There is provided a power supply device that supplies an output current to an electric processing device which performs electric processing on workpieces. The device includes: a first power supply; a magnetic energy recovery switch that receives a current supplied from the first power supply, and converts the received current into the output current; and a control unit that controls the magnetic energy recovery switch such that an electric current frequency of the output current includes a first electric current frequency and a second electric current frequency which are different from each other within a one-time electric processing time using the electric processing device.

Power supply device, joining system, and electric processing method

The present invention has as its object to inhibit fracture due to a HAZ softened part in substantially circular laser lap welding taking the place of resistance spot welding for joining a superposed plurality of steel sheets including a high strength steel sheet. To solve this problem, the inventors discovered lap welding comprising superposing a plurality of steel sheets and firing a laser to form a substantially circular laser weld (), which lap welding firing the laser in a straight line through an outer edge of the substantially circular laser weld () so as to form a hardened part () at the steel sheets and thereby suppressing fracture arising from the HAZ softened part.

Lap welding method, lap joint, production method of lap joint, and an automobile part

A server network includes a central server and store servers. Each of the store servers is connected to one or more receipt printers. The central server selects one or more store servers to which image data of an image to be added to a receipt are distributed, and transmits the image data along with condition data to the selected store servers, which are then distributed to receipt printers. Receipt printers that received the image data print one or more receipts with the additional image upon the conditions being met, and transmit content data of each printed receipt to the corresponding store server. Each of the selected store servers generates a receipt issue log based on the content data, and transmits receipt issue logs that accumulated therein to the central server. The central server calculates an amount of exposure of the additional image based on receipt issue logs.

Growing community of inventors

Tokyo, Japan

Tohru Okada