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.

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.

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 machine tool including a rotary table to which a workpiece to be subjected to machining is attached, a motor that rotates the rotary table, a brake that places the rotary table in a clamping state or an unclamping state, a valve that controls fluid supplied from a fluid supply source to the brake for placing the brake in the clamping state or the unclamping state, and a controller that controls the motor and the valve, where the controller determines whether or not rotation of the rotary table by the motor should be executed on the basis of a signal from a pressure switch of a regulator provided between the fluid supply source and the valve.

A machine tool including a rotary table to which a workpiece to be subjected to machining is attached, a motor that rotates the rotary table, a brake that places the rotary table in a clamping state or an unclamping state, a valve that controls fluid supplied from a fluid supply source to the brake for placing the brake in the clamping state or the unclamping state, and a controller that controls the motor and the valve, where the controller determines whether or not rotation of the rotary table by the motor should be executed on the basis of a signal from a pressure switch of a regulator provided between the fluid supply source and the valve.

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 feeding system with numerically adjustable pneumatic cylinder speeds includes: a frame; an X-axis pneumatic cylinder; a Z-axis pneumatic cylinder; a feeding table connected to the pneumatic cylinders in order to be driven into motion in the X- and Z-axis directions; an X-axis detection module; a Z-axis detection module; a microcomputer; and a display screen electrically connected to the microcomputer. The microcomputer uses each detection module to determine the time interval between the instant at which the piston rod of the corresponding pneumatic cylinder passes the corresponding starting point and a subsequent instant at which the same piston rod passes the corresponding endpoint. The time intervals thus determined are defined as a duration of X-axis forward movement and a duration of Z-axis forward movement respectively. Both durations are displayed on the display screen.

A feeding system with numerically adjustable pneumatic cylinder speeds includes: a frame; an X-axis pneumatic cylinder; a Z-axis pneumatic cylinder; a feeding table connected to the pneumatic cylinders in order to be driven into motion in the X- and Z-axis directions; an X-axis detection module; a Z-axis detection module; a microcomputer; and a display screen electrically connected to the microcomputer. The microcomputer uses each detection module to determine the time interval between the instant at which the piston rod of the corresponding pneumatic cylinder passes the corresponding starting point and a subsequent instant at which the same piston rod passes the corresponding endpoint. The time intervals thus determined are defined as a duration of X-axis forward movement and a duration of Z-axis forward movement respectively. Both durations are displayed on the display screen.