A rivet structure includes a female rivet plate and a male rivet plate. The female rivet plate defines an elongated countersunk hole. A size of the countersunk hole increases from a first side of the female rivet plate to a second side of the female rivet plate. The male rivet plate includes a rivet including a shaft portion and two head portions. The shaft portion extends from the male rivet plate. The two head portions are respectively arranged on opposite sides of the shaft portion on a side of the shaft portion facing away from the male rivet plate. The two head portions extend through the countersunk hole from the first side of the female rivet plate to the second side of the female rivet plate. The two head portions are configured to be stamped by a stamping member to fill in the countersunk hole.

The invention relates to a hold-down device for a joining drive and joining drive with a hold-down device. The hold-down device includes a hold-down cylinder, wherein the hold-down cylinder provides a hold-down force by means of a pressurized chamber. The pressure chamber consists of the hold-down cylinder and a punch of the joining drive. The pressurization required for the provision of the hold-down force is provided by a hydraulic circuit of the joining drive. In the joining mode, the pressure chamber of the hold-down device is connected to a pressure accumulator of the hold-down device, so that a change in volume in the pressure chamber of the hold-down device has no noticeable influence on the pressure in the pressure chamber.

A joining method is a method of joining a plate set composed by a plurality of stacked plate members including a first plate member and a second plate member by using a tapping screw. When the tapping screw is advanced into the plate set while the tapping screw is rotated in a state of applying a pressure onto the plate set so as to form through-holes in the first plate member and the second plate member, a first pressure applied onto the tapping screw is reduced down to a second pressure at the time when the tapping screw penetrates the first plate member.

A fixing device places and layers a plurality of members between a die and a punch disposed in an opposed manner, and presses and fixes the plurality of members. The plurality of members include a first member including a first fixation portion, a second member including a second fixation portion smaller than the first fixation portion, and a third member including a third fixation portion larger than the second fixation portion. The die includes a projected portion that protrudes toward the punch, and the punch includes a sheltering portion recessed along a shape of the second fixation portion. The die and the punch press the first fixation portion and the third fixation portion, thereby forming an extruded portion and forming a recess-projection fitting structure EG in a thickness direction, so that the second fixation portion is sandwiched and fixed therebetween.

A fixing device places and layers a plurality of members between a die and a punch disposed in an opposed manner, and presses and fixes the plurality of members. The plurality of members include a first member including a first fixation portion, a second member including a second fixation portion smaller than the first fixation portion, and a third member including a third fixation portion larger than the second fixation portion. The die includes a projected portion that protrudes toward the punch, and the punch includes a sheltering portion recessed along a shape of the second fixation portion. The die and the punch press the first fixation portion and the third fixation portion, thereby forming an extruded portion and forming a recess-projection fitting structure EG in a thickness direction, so that the second fixation portion is sandwiched and fixed therebetween.

A mechanical assembly for securing a first sheet to a second sheet includes a first projection having a first sidewall and a first top wall. The first sidewall extends from the first top wall at a first acute angle. The first sidewall includes a first top end and a first bottom end. A first discontinuity is defined in the first sidewall between the first top end and the first bottom end. A first base wall extends from the first bottom end. The first base wall extends generally parallel to the first top wall.

A die for deforming a workpiece material in a joining tool comprises a head with a top side partially defining a cavity in which the workpiece material is to be deformed, a bottom side opposite the top side, a lateral side arranged between the top side and the bottom side, and a stem which extends along a longitudinal axis from the bottom side of the head. The die further comprises an identification tag, preferably an RFID tag, having an antenna for receiving and/or transmitting a signal, and a storing element for storing information, and the antenna is wrapped circumferentially around the head, such that the antenna entirely surrounds the head. The head may also include a groove extending around the head on the lateral side with the antenna arranged in the groove. Additionally, the die may include a recess with the storing element located in the recess.

A fixing device places and layers a plurality of members between a die and a punch disposed in an opposed manner, and presses and fixes the plurality of members. The plurality of members include a first member including a first fixation portion, a second member including a second fixation portion smaller than the first fixation portion, and a third member including a third fixation portion larger than the second fixation portion. The die includes a projected portion that protrudes toward the punch, and the punch includes a sheltering portion recessed along a shape of the second fixation portion. The die and the punch press the first fixation portion and the third fixation portion, thereby forming an extruded portion and forming a recess-projection fitting structure EG in a thickness direction, so that the second fixation portion is sandwiched and fixed therebetween.

A fixing device places and layers a plurality of members between a die and a punch disposed in an opposed manner, and presses and fixes the plurality of members. The plurality of members include a first member including a first fixation portion, a second member including a second fixation portion smaller than the first fixation portion, and a third member including a third fixation portion larger than the second fixation portion. The die includes a projected portion that protrudes toward the punch, and the punch includes a sheltering portion recessed along a shape of the second fixation portion. The die and the punch press the first fixation portion and the third fixation portion, thereby forming an extruded portion and forming a recess-projection fitting structure EG in a thickness direction, so that the second fixation portion is sandwiched and fixed therebetween.

This adhesively-laminated core manufacturing method is a method for manufacturing an adhesively-laminated core by punching a plurality of steel sheet parts while a strip-shaped steel sheet is fed and laminating the steel sheet parts via an adhesive, and includes a step of forming a curing acceleration portion by applying and drying a curing accelerator on one or both surfaces of the strip-shaped steel sheet before a pressing oil is applied, and a step of applying the pressing oil to a surface of the curing acceleration portion.