Reinforcing Bar Tying Tool

Abstract

It includes a driving load detecting device which detects a driving load amount of a tie wire cutting mechanism, and a tie wire feeding amount control device which controls a feeding amount of the tie wire in a subsequent tying operation in accordance with the detected driving load amount. If the driving load amount when cutting the tie wire is equal to or less than a cutting determination reference value, the tie wire is fed by a normal feeding amount with a predetermined amount being added thereto in the subsequent tying operation to compensate the tie wire feeding amount, whereby a tip end of the tie wire is fed to a position which is same as the position in the normal state. The subsequent tying cycle is executed normally even if the tip end of the biding wire is failed to be clamped due to the failure of the feeding operation of the tie wire and the tie wire is pulled excessively.

1 . A reinforcing bar tying tool comprising:
 a tie wire feeding mechanism which feeds a tie wire to form a tie wire loop around reinforcing bars;   a tie wire cutting mechanism which cuts a rear end of the tie wire loop to separate the tie wire loop from a succeeding tie wire;   a tie wire twisting mechanism which clamps and twists the tie wire loop;   a driving load detecting device which detects a driving load amount of the tie wire cutting mechanism; and   a tie wire feeding amount control device which controls a tie wire feeding amount of the tie wire feeding mechanism in a subsequent tying operation in accordance with the driving load amount detected by the driving load detecting device.   
   
   
       2 . The reinforcing bar tying tool according to  claim 1 , wherein when the driving load amount detected by the driving load detecting device is equal to or less than a cutting determination reference value, the tie wire feeding amount control device controls so as to feed the tie wire by a normal tie wire feeding amount with an a predetermined amount added thereto in a subsequent tie wire feeding. 
   
   
       3 . The reinforcing bar tying tool according to  claim 1 , wherein when the driving load amount detected by the driving load detecting device is larger than a cutting determination reference value, the tie wire feeding amount control device controls so as to feed the tie wire by a normal tie wire feeding amount with an a predetermined amount added thereto in a subsequent tie wire feeding. 
   
   
       4 . The reinforcing bar tying tool according to  claim 1 , wherein the tie wire cutting mechanism cuts the rear end of the tie wire loop in a state in which the tie wire loop is brought into a close contact with the reinforcing bars by clamping a tip end of the tie wire loop with the tie wire twisting mechanism and by driving the tie wire feeding mechanism reversely to pull back the tie wire. 
   
   
       5 . The reinforcing bar tying tool according to  claim 1 , wherein the driving load detecting device detects the driving load amount of the tie wire cutting mechanism based on a current value. 
   
   
       6 . The reinforcing bar tying tool according to  claim 1 , wherein the driving load detecting device detects the driving load amount of the tie wire cutting mechanism based on a voltage value. 
   
   
       7 . The reinforcing bar tying tool according to  claim 1 , wherein the driving load detecting device detects the driving load amount of the tie wire cutting mechanism based on a rotation speed of a motor which drives the tie wire cutting mechanism.