Reading method of screw rotation angle of hand-held impact wrench, hand-vibration detection method, tightening evaluation method and control method of hand-held power screw loosening tool

A method for detecting a wobbling in a controlled tightening of a hand-held powered wrench comprising a rotary member which, after running freely, starts decelerating when it provides a hammering force to a driven shaft side and, after the end of deceleration, runs freely again without rebounding,

• wherein there is provided detecting means to detect variation in rotation velocity of the rotary member and a rotation angle of the same,
• wherein on the basis of the variation in the rotation velocity and the rotation angle in the tightening direction is detected and accumulated as a total rotation angle (P) and an angle obtained by subtracting a certain angle from a rotation angle formed throughout the deceleration is detected as ΔG and accumulated, and a preset design angle Pd for hammering corresponding to the number of hammerings provided until the end of a tightening work is accumulated, and
• wherein a wobbling angle is calculated from the following Equation:
• A wobbling angle=P−a cumulative total of Pd−a cumulative total of ΔG,
• where Pd is a design value of the powered wrench, indicating an angle corresponding to 360°/m for the case of the m number of hammerings per rotation of the rotary member.

A method for detecting wobbling in a controlled tightening of a hand-held powered wrench comprising a rotary member and a driven shaft side, wherein the rotary member, after rotating freely, starts decelerating when providing a hammering force to the driven shaft side and, after an end of deceleration, rebounds and rotates freely again, said method comprising:

• detecting variation in rotation velocity of the rotary member and a rotation angle of the rotary member via detecting means;
• detecting and accumulating a total rotation angle (P) by subtracting a cumulative total of the rotation angle of the rotary member in a rebounding direction from a cumulative total of the rotation angle of the rotary member in a tightening direction based on the variation in the rotation velocity and the rotation angle detected by the detecting means;
• detecting and accumulating a rotation angle (ΔH) formed while hammering, during deceleration, based on the variation in the rotation velocity and the rotation angle detected by the detecting means;
• accumulating a preset design angle (Pd) for hammering corresponding to a number of hammerings provided until an end of the tightening based on the variation in the rotation velocity and the rotation angle detected by the detecting means;
• and
• calculating a wobbling angle from the following Equation:
• the wobbling angle=P−a cumulative total of Pd−a cumulative total of ΔH,
• wherein Pd is a design value of the powered wrench, indicating an angle corresponding to 360°/m for a case of m number of hammerings per rotation of the rotary member.

A method for detecting wobbling in a controlled tightening of a hand-held powered wrench comprising a rotary member and a driven shaft side, wherein the rotary member, after rotating freely, starts decelerating when providing a hammering force to the driven shaft side and, after the end of deceleration, rotates freely again without rebounding, said method comprising:

• detecting variation in rotation velocity of the rotary member and a rotation angle of the rotary member via detecting means,
• detecting and accumulating a cumulative total of the rotation angle of the rotary member in a tightening direction as a total rotation angle (P) based on the variation in the rotation velocity and the rotation angle detected by the detecting means;
• detecting and accumulating an angle (ΔG) by subtracting a certain angle from a rotation angle formed throughout deceleration based on the variation in the rotation velocity and the rotation angle detected by the detecting means;
• accumulating a preset design angle (Pd) for hammering corresponding to a number of hammerings provided until an end of the tightening based on the variation in the rotation velocity and the rotation angle detected by the detecting means;
• and
• calculating a wobbling angle from the following Equation:
• the wobbling angle=P−a cumulative total of Pd−a cumulative total of ΔG,
• wherein Pd is a design value of the hand-held powered wrench, indicating an angle corresponding to 360°/m for a case of m number of hammerings per rotation of the rotary member.

A method for controlling a hand-held powered screw loosening tool comprising a rotary member and a driven shaft side having a driven shaft, wherein the rotary member, after rotating freely in a screw loosening direction, starts decelerating when providing a hammering force to the driven shaft side and, after an end of deceleration, starts rotating freely again in the screw loosening direction after or without rebounding, said method comprising:

• detecting variation in rotation velocity of the rotary member and a rotation angle of the rotary member via detecting means;
• accumulating one of the rotation angle of the rotary member in the screw loosening direction formed during the deceleration from the start to the end thereof and an angle obtained by subtracting a certain angle from the rotation angle formed during the deceleration of the rotary member, based on the variation in the rotation velocity and the rotation angle detected by the detecting means;
• and
• when a sum total of the accumulated angle reaches a preset angle, controllably stopping the rotation of the driven shaft in the screw loosening direction.

A method for controlling a hand-held powered screw loosening tool comprising a rotary member and a driven shaft side having a driven shaft, wherein the rotary member, after rotating freely in a screw loosening direction, starts decelerating when providing a hammering force to the driven shaft side and, after an end of deceleration, rotates freely again in the screw loosening direction after rebounding, said method comprising:

• detecting variation in rotation velocity of the rotary member and a rotation angle of the rotary member via detecting means;
• detecting hammering with the detecting means;
• and
• when the rotary member starts rotating freely again without rebounding after the hammering is detected or when the rotary member starts rotating freely again without the rotation velocity of the rotary member being reducing to zero, controllably stopping a rotation of the driven shaft in the screw loosening direction when the rotary member rotates continuously at or over a predetermined preset screw loosening angle.

A method for controlling a hand-held powered screw loosening tool comprising a rotary member and a driven shaft side having a driven shaft, wherein the rotary member, after rotating freely in a screw loosening direction, starts decelerating when providing a hammering force to the driven shaft side and, after an end of deceleration, rotates freely again in the screw loosening direction without rebounding, said method comprising:

• detecting variation in rotation velocity of the rotary member and a rotation angle of the rotary member via detecting means;
• detecting hammering with the detecting means;
• and
• when the rotary member rotates continuously at or over a predetermined preset screw loosening angle without the rotation velocity of the rotary member in the loosening direction after the end of deceleration being reduce below a threshold level after the generation of the hammering is detected, controllably stopping a rotation of the driven shaft in the screw loosening direction.