Abstract: A welding process for the welding of aluminum includes a force sensor measuring a force between two welding electrodes on aluminum elements to be welded and transmitting its measured values to a welding control. Until the elapse of a set welding time, the welding control calculates and stores at least one absolute value and/or at least one increase in the measured force. The welding control compares the measured absolute value and/or the increase in the measured force with a reference value and/or a reference curve and calculates a control deviation from the comparison. After the elapse of the set welding time, the welding control subjects the welding electrodes to a constant current during a welding time extension that follows the set welding time, dependent on a magnitude of the control deviation that is measured at the point in time of the elapse and/or during the set welding time.

Abstract: A welding process for the welding of aluminium includes a force sensor measuring a force between two welding electrodes on aluminum elements to be welded and transmitting its measured values to a welding control. Until the elapse of a set welding time, the welding control calculates and stores at least one absolute value and/or at least one increase in the measured force. The welding control compares the measured absolute value and/or the increase in the measured force with a reference value and/or a reference curve and calculates a control deviation from the comparison. After the elapse of the set welding time, the welding control subjects the welding electrodes to a constant current during a welding time extension that follows the set welding time, dependent on a magnitude of the control deviation that is measured at the point in time of the elapse and/or during the set welding time.

Abstract: A method for operating a welding device (1), wherein the welding device has at least one welding electrode (4), which is operated with at least one variable electrical reference value and wherein this electrical reference value is controlled by a control device (6), wherein the control of the electrical reference value takes place with allowance being made for a set of reference data (25) that is characteristic of a welding operation to be carried out. According to the invention, the set of reference data (25) is determined on the basis of at least one set of raw data (23a, 23b, 23c, 23d), wherein this set of raw data (23a, 23b, 23c, 23d) is characteristic of the welding operation to be carried out.

Abstract: A connecting element for connecting and/or fixing an electrode with an electrode arm of a welding apparatus has a base body; and a sensor selected from the group consisting of a sensor for introducing ultrasound waves into an electrode, a sensor for receiving ultrasound waves and both.

Abstract: The invention relates to an ultrasound sensor system, especially for a welding electrode, comprising a sensor (5, 6, 7, 10) which, during the detection process, passes ultrasonic waves of a desired oscillation mode into areas to be detected and/or detects ultrasonic waves. At least one material recess (2) is provided in a sensor support (1), and at least one sensor (5, 6, 7, 10) is arranged in said recess.

Abstract: A sensor carrier is provided that has at least one oscillating element (32) that introduces ultrasonic waves into an area to be examined and/or receives ultrasonic waves coming from the area to be examined, whereby the oscillating element (32) is located in an oscillator carrier (33), and the oscillator carrier (33) has connecting means (36, 37, 38, 39) for connection with the electrode (31).

Abstract: The invention relates to an ultrasonic sensor system, especially for controlling a resistance welding process. Said system comprises at least one receiver which is used to detect the ultrasonic signals from the area to be examined. At least two piezoelectric sensors (31, 32) are used as a receiver and are arranged in such a way that their polarization direction vectors indicate various directions, said vectors being projected in a plane perpendicular in relation to the propagation direction of an ultrasonic wave to be detected.

Abstract: A welding system includes a device for evaluating an ultrasonic signal during a welding process. The device has a meassured value evaluation unit that, in normal operation, evaluates at least one measurement signal that is derived from an ultrasonic signal and is located inside a measurement window. A mechanism for establishing the measurement window is provided, which establishes the measurement window according to a measurement signal that is received in a calibration operation.

Abstract: The invention relates to a device and method for determining parameters of a welding system. According to the invention, a welding area (18, 21, 22) is subjected to the action of ultrasonic waves, preferably to the action of shear waves, by using an ultrasound source (14). During a first welding process (n1), a signal processing (30) determines a first ultrasonic permeability (Dn1) from a received ultrasonic signal (UE). During at least one subsequent welding process (n2), a second ultrasonic permeability (Dn2) is determined from an ultrasonic signal (UE) that is received during a renewed exposure of the welding area (18, 21, 22) to ultrasonic waves. A display (32) and/or a diagnostic function and/or a correction of control quantities of the welding system is/are carried out as a function of the at least two ultrasonic permeabilities (Dn1, Dn2).

Abstract: A connecting element for connecting and/or fixing an electrode with an electrode arm of a welding apparatus has a base body; and a sensor selected from the group consisting of a sensor for introducing ultrasound waves into an electrode, a sensor for receiving ultrasound waves and both.

Abstract: The invention relates to a device for evaluating signals comprising a signal detection unit (26) that detects a measurement signal (UE). A measured value evaluation unit (43) evaluates measurement signals (UE) located inside a measurement window (TM1, TM2, TS1, TS2). Means (35), (37), (39) are provided for establishing the measurement window (TM1, TM2, TS1, TS2) and they establish the measurement window (TM1, TM2, TS1, TS2) according to the measurement signal (UE).

Abstract: The invention relates to a device and method for determining parameters of a welding system. According to the invention, a welding area (18, 21, 22) is subjected to the action of ultrasonic waves, preferably to the action of shear waves, by using an ultrasound source (14). During a first welding process (n1), a signal processing (30)) determines a first ultrasonic permeability (Dn1) from a received ultrasonic signal (UE). During at least one subsequent welding process (n2), a second ultrasonic permeability (Dn2) is determined from an ultrasonic signal (UE) that is received during a renewed exposure of the welding area (18, 21, 22) to ultrasonic waves. A display (32) and/or a diagnostic function and/or a correction of control quantities of the welding system is/are carried out as a function of the at least two ultrasonic permeabilities (Dn1, Dn2).

Abstract: The invention relates to an ultrasonic sensor system, especially for controlling a resistance welding process. Said system comprises at least one receiver which is used to detect the ultrasonic signals from the area to be examined. At least two piezoelectric sensors (31, 32) are used as a receiver and are arranged in such a way that their polarisation direction vectors indicate various directions, said vectors being projected in a plane perpendicular in relation to the propagation direction of an ultrasonic wave to be detected.

Abstract: A sensor carrier is provided that has at least one oscillating element (32) that introduces ultrasonic waves into an area to be examined and/or receives ultrasonic waves coming from the area to be examined, whereby the oscillating element (32) is located in an oscillator carrier (33), and the oscillator carrier (33) has connecting means (36, 37, 38, 39) for connection with the electrode (31).

Abstract: Finely divided hexagonal ferrite powder is prepared by autoclave treatment of an aqueous alkaline suspension containing the ferrite-forming metal ions at from 250.degree. to 330.degree. C. and subsequent heating of the resulting material at not more than 900.degree. C., by a process in which the ferrite-forming metal ions are used in the form of salts melted in their water of crystallization.

Abstract: Finely divided acicular and pore-free .alpha.-Fe.sub.2 O.sub.3 is prepared from an iron(III) salt in the presence of one or more organic substances which form complexes with iron(III) ions, in alkaline supension at from 80.degree. to 250.degree. C., and is used for the preparation of magnetic materials suitable for magnetic recording media.

Abstract: Finely divided, acicular and pore-free .alpha.-Fe.sub.2 O.sub.3 is prepared from iron(III) salts in the presence of one or more organic substances which form complexes with iron(III) ions, in alkaline suspension, at from 80.degree. to 250.degree. C.

Abstract: Acicular .alpha.-Fe.sub.2 O.sub.3 is prepared from iron(III) salts by heating an alkaline aqueous suspension of iron(III) hydroxide in the presence of one or more organic substances which form complexes with iron(III) ions to a temperature of 100.degree. C. or less.