US 2007/0163357 A1 · Electric screwdriver and a controller thereof

Abstract

An object of the present invention is to provide an electric screwdriver device having a function for determining that a correct tightening operation has been carried out when the tightening operation has taken a time longer than a reference time predetermined for the tightening operation, characterized in comprising a novel means for determining the reference time. The electric screwdriver device of the present invention comprises a torque monitoring means (40, S4) for monitoring whether or not a load torque in carrying out the tightening by using the electric screwdriver 12 has reached the tightening completion torque, a timer means (40, S1, S5) for measuring the time consumed from the starting of the tightening operation until the tightening torque has reached the tightening completion torque, as the tightening operation time, and a means (40, S6-S10) for determining the reference time for a subsequent tightening operation based on a plurality of tightening operation time obtained from the timer means in the tightening operations carried out for the predetermined number of screws.

Claims14

Dependent claims

An electric screwdriver controller having a function for determining that a correct tightening operation has been carried out when said tightening operation has taken a time longer than a reference time, said controller comprising:

a torque monitoring means for monitoring whether or not a load torque in carrying out a tightening operation by using an electric screwdriver has reached a tightening completion torque indicating a completion of the tightening operation;
a timer means for measuring a time interval from a starting time of the tightening operation to a time when the tightening torque has reached the tightening completion torque, as a tightening operation time;
and
a means for determining a reference time for a subsequent tightening operation based on a plurality of tightening operation times obtained from said timer means in the tightening operations carried out for a predetermined number of screws.

1 more element

An electric screwdriver device comprising an electric screwdriver and a controller connected to said electric screwdriver, in which

said controller comprises:
a power source and a power circuit for said power source, said power circuit having a function for selectively providing an output for a normal rotation from said power source or an output for a reverse rotation from said power source in accordance with a normal rotation signal or a reverse rotation signal given by said electric screwdriver and for shutting down an output from said power source in accordance with a stop signal of said electric screwdriver or a tightening completion signal generated by said electric screwdriver;
and
a tightening completion signal and reverse rotation signal processing means for processing said tightening completion signal and
said reverse rotation signal, and said electric screwdriver comprises:
a screwdriver motor to be connected to the power source terminals of said power circuit;
a common line for supplying a reference voltage;
a normal rotation/reverse-rotation shifting switch for shifting between the normal rotation and the reverse-rotation of the screwdriver motor;
a first signal line for interconnecting a first output terminal of said normal rotation/reverse-rotation shifting switch and said controller;
a second signal line for interconnecting a second output terminal of said normal rotation/reverse-rotation shifting switch and said controller;
a starting switch connected between said common line and a first input terminal of said normal rotation/reverse-rotation shifting switch;
and
a braking switch connected between said starting switch and a second input terminal of said normal rotation/reverse-rotation shifting switch,
said normal rotation/reverse-rotation shifting switch being capable of switching between
a normal rotation connecting position where it is operable to connect said starting switch to said first signal line and to connect said braking switch to said second signal line
and a reverse rotation connecting position where it is operable to connect said starting switch to said second signal line and to connect said braking switch to said first signal line,
said starting switch being adapted
to supply a start signal and a stop signal from said first signal line to said controller, respectively, by turning on and off during said normal rotation/reverse-rotation shifting switch being positioned in said normal rotation connecting position, and
to supply the starting signal and the stop signal from said second signal line to said controller, respectively, by turning on and off during said normal rotation/reverse-rotation shifting switch being positioned in said reverse rotation connecting position, and
said braking switch being adapted,
in case of it being a normal-open type switch, to be closed when the tightening completion torque for the tightening operation having been reached and to supply a tightening completion signal to said controller, and
in case of it being a normal-close type switch, to be opened when the tightening completion torque for the tightening operation having been reached and to supply a tightening completion signal to said controller.

19 more elements

An electric screwdriver device comprising an electric screwdriver and a controller connected to said electric screwdriver, in which

said controller comprises:
a power source and a power circuit for said power source, said power circuit having a function for selectively providing an output for a normal rotation from said power source or an output for a reverse rotation from said power source in dependence on a normal rotation signal or a reverse rotation signal given by said electric screwdriver and for shutting down an output from said power source in dependence on a stop signal of said electric screwdriver or a tightening completion signal generated by said electric screwdriver;
and
a tightening completion signal and reverse rotation signal processing means for processing said tightening completion signal and said reverse rotation signal,
and said electric screwdriver comprises:
a screwdriver motor to be connected to the power source terminal of said power circuit;
a common line provided as a line defined in the ground side;
a normal rotation/reverse-rotation shifting switch for shifting between the normal rotation and the reverse-rotation of the screwdriver motor;
a first signal line for interconnecting a first input terminal of said normal rotation/reverse-rotation shifting switch and said controller;
a second signal line for interconnecting a second input terminal of said normal rotation/reverse-rotation shifting switch and said controller;
a starting switch connected between said common line and a first output terminal of said normal rotation/reverse-rotation shifting switch;
and
a braking switch connected between said starting switch and a second output terminal of said normal rotation/reverse-rotation shifting switch,
said normal rotation/reverse-rotation shifting switch being capable of switching between
a normal rotation connecting position where it is operable to connect said starting switch to said first signal line and to connect said braking switch to said second signal line and
a reverse rotation connecting position where it is operable to connect said starting switch to said second signal line and to connect said braking switch to said first signal line, and
said starting switch being adapted
to supply a start signal and a stop signal from said first signal line to said controller, respectively, by turning on and off during said normal rotation/reverse-rotation shifting switch being positioned in said normal rotation connecting position, and
to supply the start signal and the stop signal from said second signal line to said controller, respectively, by turning on and off during said normal rotation/reverse rotation shifting switch being positioned in said reverse rotation connecting position, and
said braking switch being adapted,
in case of it being normal-open type switch, to be closed when the tightening completion torque for the tightening operation having been reached and to supply a tightening completion signal to said controller, and
in case of it being normal-close type switch, to be opened when the tightening completion torque for the tightening operation having been reached and to supply a tightening completion signal to said controller.

19 more elements

Dependencies are inferred from the claim text.

Electric screwdriver and a controller thereof

Life of this patent

Electric screwdriver and a controller thereof

Life of this patent

Abstract

Claims14