- •Передмова
- •Lesson 1 The reading module
- •The speaking module
- •II. Speaking Exercises:
- •The writing module
- •Lesson 2 The reading module
- •After text activity
- •The speaking module
- •Lesson 3 The reading module
- •The writing module
- •The speaking module
- •The writing module
- •Lesson 4 The reading module
- •The writing module
- •Lesson 5 The reading module
- •The speaking module
- •The writing module
- •Lesson 6 The reading module
- •Integrated safety
- •The speaking module
- •Lesson 7 The reading module
- •The speaking module
- •The writing module
- •Lesson 8 The reading module
- •The speaking module
- •The writing module
- •Lesson 9 The reading module
- •The speaking module
- •The writing module
- •Lesson 10 The reading module
- •The speaking module
- •The writing module
- •In, with, on, but , of
Lesson 10 The reading module
Read the text: VERIFYING ON THE MACHINE
On-machine verification technology comprises in-process probes and inspection software that lets manufacturers automatically monitor, correct, and document in-process operations. One such system combines MP 700 or soon-to-be-released OMP 400 spindle probes from Renishaw Inc., Hoffman Estates, Ill., and PowerInspect software from Delcam USA, Salt Lake City, Utah.
The probes, touch-trigger sensors that mount in a machine tool spindle or turret, feed data gaged relative to the machine's coordinate system back to the controller for compensation in the machining program. They are used just like any other tool in the machine. However, instead of cutting, the probe touches part surface gage-reference points (typically defined in CAD/CAM systems) to monitor the size and position of critical points at certain stages of machining. Renishaw probes don't require calibration in all the vectors in which they are to be used. This reduces the number of points required to measure a given part and speeds verification.
The inspection software allows CAD-to-part comparison, with GD&T capabilities such as perpendicularity, angularity, parallelism, and concentricity. Wizards help users develop the inspection sequence, making it easy to generate required probe paths. All measurements are initially displayed as green, red, or blue dots, depending on whether the point taken is within, above, or below tolerance. At the end of the process, customizable reports can be generated that can quickly show whether the part has been made accurately and highlight areas that might give cause for concern. The program also allows offline programming of the inspection sequence and includes simulation and collision checking. This minimizes time required for verification operations.
The system can monitor component quality at all stages of the manufacturing process. For example, it can check that the correct amount of stock has been left after a roughing operation, or assess the extent of damage due to tool breakage. This permits immediate decisions as to whether a part can be completed within tolerance, or must be scrapped.
ARTIFACT COMPARISON
Of course, measurements made with a machine tool on the shop floor cannot duplicate the accuracy of a dedicated CMM in a climate-controlled environment. Such a level of precision may be impressive, but it's rarely needed in most manufacturing operations. In addition, the quality of the on-machine results can be checked against known artifacts in a technique invented by Renishaw.
An artifact is a master part made from the same material by the same manufacturing operations as parts being machined. It need not have all the features of the finished part, but it does have the critical gage points.
Next, the artifact is located in the machining envelope, usually as part of the fixture. At various points in the machining cycle, a spindle mounted probe measures the size of a feature on the artifact for comparison with the program part dimensions. Any difference can then be compensated in machining that feature on the workpiece. According to the company, manufacturers can use this technique on almost any machining center, holding tolerances near the machine's repeatability specification as well as compensating for thermal effects.
I. Reading Exercises:
Exercise 1. Read and memorize using a dictionary:
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touch-trigger sensors, turret, calibration, vectors, to measure, comparison, capability, to generate, machine tool, artifact, difference, thermal effects |
Exercise 2. Answer the questions:
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What does on-machine verification technology comprise ?
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Where do the probes, touch-trigger sensors mount ?
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What can monitor component quality at all stages of the manufacturing process?
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When can customizable reports be generated that can quickly show whether the part has been made accurately and highlight areas that might give cause for concern ?
Exercise 3. Match the left part with the right:
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1. The system can |
a) offline programming of the inspection sequence and includes simulation and collision checking. |
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2. The program also allows |
b) monitor component quality at all stages of the manufacturing process. |
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3. Renishaw probes don't require |
c) that feature on the workpiece. |
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4. Any difference can then be compensated in machining |
d) calibration in all the vectors in which they are to be used. |
Exercise 4. Open brackets choosing the right words:
The system can ( monitor / work) component quality at all stages of the manufacturing process. For example, it can ( check/require) that the correct amount of stock has been( left/depended) after a roughing operation, or assess the extent of damage due to tool breakage. This( permits/uses) immediate decisions as to whether a part can be completed within tolerance, or must be scrapped.