Tool holder for monitoring tool service time

• US 4,890,306 A
• Filed: 03/14/1988
• Issued: 12/26/1989
• Est. Priority Date: 03/30/1987
• Status: Expired due to Fees

• Current Assignee: Toyoda Machine Works Limited Toyoda-Koki Kabushiki Kaisha
• Original Assignee: Toyoda Machine Works, Ltd.
• Inventors: Noda, Shigeo
• Primary Examiner(s): Heyman, John S.
• Application Number:
  US07/167,918
• Time in Patent Office: 652 Days
• Field of Search: 377/15, 377/16, 377/20, 377/24.1, 408/6, 408/16, 409/234, 29/568
• US Class Current: 377/15
• CPC Class Codes: B23B 2231/10 Chucks having data storage chips
• CPC Class Codes: B23B 31/006 Conical shanks of tools
• CPC Class Codes: B23Q 17/0995 Tool life management
• CPC Class Codes: Y10T 408/14 Responsive to condition of Tool or tool-drive
• CPC Class Codes: Y10T 408/21 with signal, indicator, illuminator or optical means
• CPC Class Codes: Y10T 409/30952 with cutter holder
• CPC Class Codes: Y10T 483/134 Identifying information on tool or tool holder
• CPC Class Codes: Y10T 483/14 with signal or indicator

Abstract

A tool holder for monitoring the service time of a tool holded on the tool holder is disclosed. A sensor and electric circuit are provided for determining whether or not the machining operation with the tool is executed. Counters are provided for counting time cumulatively during the time when the machining operation is executed, and store the cumulative time as the service time of the tool. The service time is output to a numerical control apparatus via an output device.

Claims

1. A tool holder holding a tool and replaceably attached to a main spindle of a machine tool, said tool holder comprising:

a body holding said tool;

sensor means provided in said body for detecting whether or not said tool is used in a machining operation;

counter means provided in said body for counting time cumulatively during the time when the output signal from said sensor means indicates that said tool is used, and for storing said cumulatively counted time as service time;

output means provided in said body for outputting said service time held in said counter means to an outside circuit; and

reset switch means provided on said body for resetting said counter means, whereby said counter means may be reset when said tool is reground or replaced.

2. A tool holder as set forth in claim 1, wherein said sensor means comprises:

an acceleration sensor provided in said body for detecting centrifugal force acting to said body which occurs due to the rotation of said tool; and

an electrical circuit for judging whether or not said tool is used depending on the output signal of said acceleration sensor.

3. A tool holder as set forth in claim 1, wherein said sensor means comprises:

a pressure sensor attached to said body for detecting a machining reaction reaction force acting on said body; and

an electrical circuit for judging whether or not said tool is used depending on the output signal of said pressure sensor.

4. A tool holder as set forth in claim 1, further comprising memory means provided in said body for memorizing a predetermined lifetime of said tool, and said output means output said lifetime to said outside circuit as well as said service time.