Numerical control device for predicting a machining termination

Electricity: motive power systems – Positional servo systems – Program- or pattern-controlled systems

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Other Related Categories

318601, 36447416, G05B 1918

Type

Patent

Status

active

Patent number

055149413

Description

DESCRIPTION:

BRIEF SUMMARY
TECHNICAL FIELD

The present invention relates to a numerical control device for reporting an expected termination time of program machining using an NC machine tool.


BACKGROUND ART

Totally unmanned operation is practical in program machining using an NC machine tool, and an operator need not monitor the machining work except for prearranging operations such as mounting of workpieces, starting of machining programs, etc. Thus, while the NC machine tool is executing programmed machining, the operator can perform prearranging operations for the next machining cycle or other odd jobs. If the operator is previously informed of the time of termination of the machining, however, he can more smoothly carry out operations such as removal of machined workpieces, transfer of workpieces to the next machining stage, etc.
Conventionally, in order to know an expected machining termination time, the operator used to compute a required machining time manually in accordance with the machining shape, set machining speed, etc. given by a machining program, thereby estimating the time when the machining would terminate. However, when one and the same portion of a workpiece has to be finished, for example, by repeating several machining cycles ranging from rough machining to finish machining, machining conditions naturally vary with the individual cycles, so that the average speed of tool movement for each cycle, tool offset value for each cycle, and, therefore, tool movement path length for each cycle (overall length of machining locus for each machining stage) vary. Accordingly, the machining time varies with the individual machining stages. Thus, in order to estimate the necessary machining time for any one portion of workpiece in advance, various conditions such as the machining frequency, machining conditions for each machining stage, tool offset value, etc., besides the machining shape given by the machining program, should be taken into consideration, and an accurate estimation usually requires complicated calculations.
Some NC machine tools are designed for being capable of adaptively controlling the machine speed in order to obtain uniform work surfaces. In the cases of the NC machine tools with such arrangement, however, the set machining speed does not always agree with the actual machining speed. Even though complicated manual calculations are made in consideration of the offset value and the like, the required time calculated not based on the actual machining speed but based on the set machining speed may lack in accuracy in some cases.


SUMMARY OF THE INVENTION

The object of the present invention is to provide a numerical control device, in which the aforesaid drawbacks of the prior art are eliminated; the operator can easily be informed of an expected machining termination time without performing time-consuming calculating operations; and expected machining termination time can be detected more accurately than by the conventional method despite a difference even when actual speed deviates from set machining speed.
In order to achieve the above object, according to an aspect of the present invention, a numerical control device for controlling a machine tool comprises: a required machining time computing means for computing a time required for the execution of an entire machining operation based on a machining program in accordance with a work load and a set machining speed given by the machining program; a clock means to operate synchronously with the current time; an expected machinining termination time computing means for computing an expected machining termination time in accordance with the required time computed by the required machining time computing means and the current time given by the clock means; and a display means for displaying the expected machining termination time.
According to another aspect of the present invention, moreover, a numerical control device for controlling a machine tool comprises: a machining speed detecting means for detecting the actual machining speed during the executio

REFERENCES:
patent: 4980532 (1990-12-01), Morishita

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Numerical control device for predicting a machining termination does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Numerical control device for predicting a machining termination , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Numerical control device for predicting a machining termination will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-1229329

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.