Title:
AUTOMATIC FEEDING CONTROL DEVICE
Document Type and Number:
Japanese Patent JP3707656
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To precisely detect a change of a load at the time a cutter provided on an electric drill bites in a surface of a work and at the time when it runs through the work.
SOLUTION: When a starting switch 6 is switched on and a contact point 6B and a contact point 6C are connected to each other, a microcomputer 58 detects an electric drill electric current value at the time of no load rotation by input from a transformer 54 for electric current detection. Thereafter, a first threshold value is found by adding an electric current value lower than an electric current value generated at the time when a cutter bites in a surface of a work as a bias electric current to the electric drill electric current value at the time of no load rotation. Thereafter, when the electric drill electric current value detected from the transformer 54 for electric current detection exceeds the first threshold value, it is judged that the cutter bites in the surface of the work. Additionally, when a second threshold value which is higher than a normal drill electric current value at the time of electric drill no load rotation is set and the electric drill electric current value becomes higher than the second threshold value in the middle of drilling, it is judged that drilling is finished.
Inventors:
Giichiro Shimizu
Masayuki Saito
Masayuki Saito
Application Number:
JP286099A
Publication Date:
October 19, 2005
Filing Date:
January 08, 1999
Export Citation:
Assignee:
Nitto Kohki Co., Ltd.
International Classes:
B23Q5/22; B23B45/14; B23B47/18; B23Q15/013; (IPC1-7): B23B47/18; B23B45/14; B23Q5/22
Domestic Patent References:
| JP9141509A | ||||
| JP8290312A | ||||
| JP6143015A |
Attorney, Agent or Firm:
Kaori Tanaka
Michito Hiraki
Michito Hiraki