Data processing: measuring – calibrating – or testing – Measurement system in a specific environment – Mechanical measurement system
Reexamination Certificate
2000-07-27
2002-11-19
Hilten, John S. (Department: 2863)
Data processing: measuring, calibrating, or testing
Measurement system in a specific environment
Mechanical measurement system
C702S033000
Reexamination Certificate
active
06484106
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to mechanical presses and, more particularly to a method and apparatus for determining optimal press usage and for making repair and/or replacement recommendations as well as continued usage recommendations based upon the analysis performed for a manufacturing facility. Press usage analysis includes analysis of die load, tipping moment, vibration severity, die chipping and/or press die repair or maintenance information. The usage recommendations will lead to greater productivity within a plant site, as well as, press and machine longevity.
2. Description of the Related Art
Conventional press machines employ a tooling apparatus in the form of a die assembly to shape a workpiece, such as in a stamping or drawing operation. The die assembly particularly includes a lower die attached to a non-moveable bed or bolster and an upper die or punch attached to a reciprocating slide. The upper and lower dies, which are installed in opposing spaced apart relation to one another, cooperate during press machine operation to mutually engage the workpiece at respective sides thereof to thereby effect the desired forming activity.
Repeated stamping operations of a mechanical press cause die wear. The ability to accurately predict die wear or to predict operating conditions which indicate the propensity for increased die wear is advantageous in that press down time for die replacement or reconditioning can be predicted or even potentially diverted by proactive early corrective intervention. The ability to predict die wear allows the operator of a mechanical press to better plan times for die replacement or to intervene with corrective actions, so that productivity loss is not experienced. Further, the ability to predict die wear is advantageous in that press down time associated with die maintenance can be minimized. To accurately predict die wear, tipping moment severity must be accounted for. Since die wear is useful in increasing productivity, tipping moment severity forms a part of the analysis system of the present invention.
A press applies force to a workpiece so that the workpiece (i.e. stock material) acquires the desired formation corresponding to the die set being utilized. Systems for monitoring press operating reliability assist the press owner in evaluating the impact of certain die/load applications on the reliability of the press being monitored. Monitoring systems include systems which utilize contact load sensors to monitor the peak load being developed within certain components of the press machine during a slide stroke of the press. Known methods of monitoring peak loads utilize a strain gage or other transducer which is mounted on the press and which directly measures a value of applied load. Monitoring load exerted on load bearing members during a slide stroke of a mechanical press allows press and die applications to be adjusted when monitored peak load values are outside an acceptable range. Load values not only provide valuable press adjustment information, but also provide valuable use severity information.
Most mechanical systems, including mechanical presses, have a certain operational lifetime based upon their material of construction, their structure, and the level of use which they experience. Use experienced by a mechanical device can be measured by many indicators, such as time of use and severity of use. Many factors may contribute to the severity of use of a mechanical device. The severity of use of a mechanical press can be measured in many ways including, for example, vibration severity experienced during press operation, tipping moment severity experienced during press operation, applied load, dynamic parallelism, and whether the press has been run with a chipped die in place.
What is needed in the art is an implementation methodology to monitor and evaluate mechanical presses in use which combines all of the above-mentioned indicators of use severity.
What is further needed in the art is a method and apparatus which can be utilized to measure the use severity of mechanical presses in operation and which will be effective in establishing which presses could experience increased use severity and which presses should be run at a decreased level of use severity.
Further, this methodology will also identify which presses and applications can be operated at greater productivity with optimized operating conditions.
SUMMARY OF THE INVENTION
The present invention is directed to improve upon the ability to accurately monitor and evaluate mechanical presses used within facilities and to provide a systematic method for solving a multitude of mechanical press problems at once.
The invention, in one form thereof, comprises a method of monitoring, analyzing and managing mechanical press usage. The method of this form of the current invention includes the steps of: monitoring vibration severity, including vibration severity zone; monitoring tipping moment severity; monitoring press repair information, including die repair information; monitoring press maintenance information, including die maintenance information; monitoring press applied load; and analyzing the effect of vibration severity, tipping moment severity, press repair, press maintenance and applied load to determine necessary press modifications.
In one form of the current invention, tipping moment severity is monitored by attaching a load sensor to the bed of a running press or connecting sensors to the slide connections, uprights, or dies. A computational device is communicatively connected to the sensor and is operative to compute and measure tipping moment severity of the running press based upon the sensed load value and methods for computing moments. Other sensors may measure load versus time, or right versus left type forces. The computational device can be, for example, a microprocessor.
The invention, in another form thereof, includes a means for measuring die life risk condition based upon tipping moment severity. Die life risk condition provides another useful measure of pressure severity. One or more load sensors are attached to the bed, connections or other locations of a running press and a computational device which stores a unique tipping moment severity chart for the running press, a plurality of tipping moment severity factors which correspond to zones of tipping moment severity on the tipping moment severity chart and a plurality of zone of criticality factors which correspond to the zones of criticality on the tipping moment severity chart is provided. The computational device receives the load values sensed from the load sensors and uses means to compute tipping moments based upon the sensed load values. The computational device also utilizes the tipping moment severity chart, the tipping moment severity factors, the zone of criticality factors, and the measured tipping moment to compute a measure of die life risk condition. Load may also be computed based upon theoretical load analysis as described below.
An advantage of the present invention is the ability to lessen the tipping moment of the die so as to decrease die chipping, die repair and die maintenance.
Another advantage of the present invention is the ability to increase production by decreasing the use severity of particular applications, or increasing the maximum severity capability of the press which is then better able to handle such an increased use severity. Press Applications may be transferred to an alternate press better suited for utilization of that particular press application.
A further advantage of the present invention is the ability to effectively increase mechanical press production while keeping the impact of press use severity to a minimum.
REFERENCES:
patent: 3872285 (1975-03-01), Shum et al.
patent: 4048848 (1977-09-01), Dybel
patent: 4116050 (1978-09-01), Tanahashi et al.
patent: 4453421 (1984-06-01), Umano
patent: 4633720 (1987-01-01), Dybel et al.
patent: 5094107 (1992-03-01), Schoch
patent: 5423199 (1995-06-01), Mangrulkar
Hilten John S.
Knuth Randall J.
Sun Xiuquin
The Minster Machine Company
LandOfFree
Mechanical device productivity improvement with usage... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mechanical device productivity improvement with usage..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mechanical device productivity improvement with usage... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2985215