Methods and devices for controlling a mechanical joining or forming process, in particular friction drilling in thin-walled materials, apply several reverse pulses acting on a process parameter to bring the course of an actual curve of the parameter more into line with the course of a predetermined nominal curve of the process parameter. The number and length of the reverse pulses and the length of the intervals between the pulses are determined as a function of at least one immediately detectable variable associated with the process parameter.

A transmission structure of a drilling machine contains: a housing, a drive shaft, a drive gear, a guide gear, a speed change gear assembly, a driven gear assembly, and a control knob. The housing include a first accommodation groove for housing the drive shaft, a second accommodation groove for accommodating the guide shaft, a third accommodation groove for housing the speed shaft, and a fourth accommodation groove for accommodating the driven shaft. The drive gear is connected on the drive shaft, and the guide gear is coupled on the guide shaft and meshes with the drive gear. The speed change gear assembly includes a connection gear and at least two speed change gears. The driven gear assembly includes at least two driven gears corresponding to at least two speed change gears respectively. The control knob configured to drive the driven gear assembly to move upward and downward.

A transmission structure of a drilling machine contains: a housing, a drive shaft, a drive gear, a guide gear, a speed change gear assembly, a driven gear assembly, and a control knob. The housing include a first accommodation groove for housing the drive shaft, a second accommodation groove for accommodating the guide shaft, a third accommodation groove for housing the speed shaft, and a fourth accommodation groove for accommodating the driven shaft. The drive gear is connected on the drive shaft, and the guide gear is coupled on the guide shaft and meshes with the drive gear. The speed change gear assembly includes a connection gear and at least two speed change gears. The driven gear assembly includes at least two driven gears corresponding to at least two speed change gears respectively. The control knob configured to drive the driven gear assembly to move upward and downward.

According to one implementation, a tool feeding mechanism for a handheld tool rotating device, having a holder and a first air motor, includes a coupler, a fixing member, a moving mechanism and a second air motor. The holder chucks and holds a rotating tool. The first air motor rotates the holder. The tool feeding mechanism is attached to the tool rotating device. The coupler is attached to the tool rotating device. The fixing member is attached directly or indirectly to a workpiece of hole processing using the rotating tool. The moving mechanism moves the coupler relatively to the fixing member in a tool axis direction. The second air motor powers the moving mechanism.

According to one implementation, a tool feeding mechanism for a handheld tool rotating device, having a holder and a first air motor, includes a coupler, a fixing member, a moving mechanism and a second air motor. The holder chucks and holds a rotating tool. The first air motor rotates the holder. The tool feeding mechanism is attached to the tool rotating device. The coupler is attached to the tool rotating device. The fixing member is attached directly or indirectly to a workpiece of hole processing using the rotating tool. The moving mechanism moves the coupler relatively to the fixing member in a tool axis direction. The second air motor powers the moving mechanism.

A drilling device having a motor for driving a tool received in a tool holder, wherein the motor is coupled to a power source providing electrical operating power, and having a first switch for switching on the motor. A temperature switching element is provided, which is reversibly transferred from a first switching position to a second switching position, which shuts off the motor when the limit temperature of the switched-on motor is exceeded. For cooling the motor, the first switch and the temperature switching element are connected such that in the second switching position of the temperature switching element, it is possible to switch on the motor by pressing and holding the first switch. Moreover, the invention relates to a method for operating a drilling device.

A drilling device having a motor for driving a tool received in a tool holder, wherein the motor is coupled to a power source providing electrical operating power, and having a first switch for switching on the motor. A temperature switching element is provided, which is reversibly transferred from a first switching position to a second switching position, which shuts off the motor when the limit temperature of the switched-on motor is exceeded. For cooling the motor, the first switch and the temperature switching element are connected such that in the second switching position of the temperature switching element, it is possible to switch on the motor by pressing and holding the first switch. Moreover, the invention relates to a method for operating a drilling device.

A tool drive with spindle shaft for a chip-forming machining includes at least one electromagnetic axial actuator and a control and/or regulation apparatus for the operation of the axial actuator for changing the position of the spindle shaft along the longitudinal axis. The control and/or regulation apparatus is designed to drive the axial actuator for the generation of microvibration movement of the spindle shaft, independently of and superimposable on a feed movement, in order to affect the chip size and chip shape of the removed material. At least one axial magnetic bearing and/or one linear motor is provided as at least part of the axial actuator, hi an operating method for an above-mentioned tool drive with a spindle shaft and an axial magnetic bearing is proposed, wherein an adjustable axial microvibration movement of the spindle shaft is superimposed through at least one electromagnetic axial actuator, independently of a feed, in order to influence the chip size and chip shape of the material removed from holes.

A tool drive with spindle shaft for a chip-forming machining includes at least one electromagnetic axial actuator and a control and/or regulation apparatus for the operation of the axial actuator for changing the position of the spindle shaft along the longitudinal axis, wherein the control and/or regulation apparatus is designed to drive the axial actuator for the generation of microvibration movement of the spindle shaft, independently of and superimposable on a feed movement, in order to affect the chip size and chip shape of the removed material, wherein at least one axial magnetic bearing and/or one linear motor is provided as at least part of the axial actuator, wherein the regulation and/or control apparatus includes a memory unit and/or a function generation unit, and is configured to specify setpoint values of the oscillation curve of the microvibration movement depending on geometrical and or physical data of the workpiece and/or process variables that are measured or determined indirectly and/or control inputs, so that the control and/or regulation apparatus is configured to adjust an axial microvibration movement of the spindle shaft, independently of and superimposed on a feed movement, in such a way as to affect the chip size and chip shape of the removed material created when drilling.

A controller for a tool drive that collects force data and displacement data from the tool drive. The controller generates a stiffness model representing a workpiece using the force data and the displacement data. The controller further collects a force signal from the tool drive. The controller determines deflection of the workpiece using the force signal and stiffness model. The controller determines a resonant frequency of the workpiece using the stiffness model. The controller modifies an oscillation frequency and/or a rotational frequency of a spindle of the tool drive based on the resonant frequency. The controller also determines a location of a tip of the tool drive using the force signal.