摘要:
A method and apparatus are disclosed for inserting a pouring pipe into a mold of a continuous casting machine. The pouring pipe is mounted in a truck, and the truck and pouring pipe combination are then mounted on a conveyor mechanism such that the pouring pipe is set in a substantially horizontal starting position. From this substantially horizontal starting position, the pouring pipe is guided along a pair of guide rails of the conveyor mechanism such that is pivots into a substantially vertical position and is moved into a waiting position wherein its lower end is inserted into the mold. In this waiting position, the pouring pipe is offset laterally from but aligned with a casting opening in the bottom wall of the metallurgical vessel. From this waiting position, the pouring pipe can be forced by a pusher mechanism into a pouring position beneath the casting opening of the metallurgical vessel, such that molten metal can be poured from the metallurgical vessel into the mold via a pouring pipe. This procedure can be repeated by moving a new pouring pipe into the waiting position, after a pouring pipe in the waiting position has been moved from the waiting position into the pouring position, thereby displacing the eroded pouring pipe from the pouring position into a discharge position from which it can be removed from the continuous casting machine.
摘要:
The invention relates to a method for operating a brushless electric motor, the windings of which are controlled by an inverter using six switches, wherein the inverter comprises three outputs, which are associated with the windings of the electric motor, and wherein a respective power semiconductor switch is arranged between the output of the inverter and the windings, and wherein a detection unit for detecting defective switches, a unit for measuring the voltage at the outputs of the inverter, and a microcontroller for controlling switches are provided. The invention further relates to a device operating a brushless electric motor. In order not to damage the power semiconductor switches, according to the invention of the inverter is switched off by the microcontroller after a defective switch has been detected, such that no additional power is introduced in the windings (U, V, W) of the electric motor and the power semiconductor switches are opened in a predetermined motor angle position (φU, φv, φw). For said purpose, the motor angle positions (φu, φv, φw) are associated with a respective winding (U, V, W) and the power semiconductor switches thereof and are selected such that the associated power semiconductor switches are not damaged during opening.
摘要:
The invention relates to a method for operating a brushless electric motor, the windings of which are controlled by an inverter using six switches, wherein the inverter comprises three outputs, which are associated with the windings of the electric motor, and wherein a respective power semiconductor switch is arranged between the output of the inverter and the windings, and wherein a detection unit for detecting defective switches, a unit for measuring the voltage at the outputs of the inverter, and a microcontroller for controlling switches are provided. The invention further relates to a device operating a brushless electric motor. In order not to damage the power semiconductor switches, according to the invention of the inverter is switched off by the microcontroller after a defective switch has been detected, such that no additional power is introduced in the windings (U, V, W) of the electric motor and the power semiconductor switches are opened in a predetermined motor angle position (φU, φv, φw). For said purpose, the motor angle positions (φU, φv, φw) are associated with a respective winding (U, V, W) and the power semiconductor switches thereof and are selected such that the associated power semiconductor switches are not damaged during opening.
摘要:
The present invention relates to a method for operating a brushless electric motor whose windings are driven by an inverter with the aid of six switches, having an identification unit being provided in order to identify defective switches, a unit for voltage measurement at the outputs of the inverter, and a microcontroller for controlling the switches. Particularly in safety-relevant applications, it is important to quickly determine what characteristic the defective switch has, for example in order to continue to operate the electric motor in an emergency mode, or to switch it off immediately. The defect (F1, F2, F3) is traced and the nature of the defect (F1, F2, F3) in a switch determined by using a different voltage (PWM1, PWM2) to drive those windings (V, W) which are not associated with the defective switch, while a voltage measurement is carried out on the winding (U) associated with the defective switch.
摘要:
The present invention relates to a method for operating a brushless electric motor whose windings are driven by an inverter with the aid of six switches, having an identification unit being provided in order to identify defective switches, a unit for voltage measurement at the outputs of the inverter, and a microcontroller for controlling the switches. Particularly in safety-relevant applications, it is important to quickly determine what characteristic the defective switch has, for example in order to continue to operate the electric motor in an emergency mode, or to switch it off immediately. The defect (F1, F2, F3) is traced and the nature of the defect (F1, F2, F3) in a switch determined by using a different voltage (PWM1, PWM2) to drive those windings (V, W) which are not associated with the defective switch, while a voltage measurement is carried out on the winding (U) associated with the defective switch.
摘要:
An internal combustion engine includes an electromagnetic actuator for operating a gas exchange valve, this actuator being situated on a cylinder head. The actuator includes a switchable electromagnet which is situated between two armatures. The armatures are axially set apart on a common armature shaft. A cavity is configured in the cylinder head, in which the actuator armature on the cylinder head side is at least partially accommodated, and the electromagnet at least partially delimits the cavity on the actuator side. This results in a compact internal combustion engine.