Sturtevant Richmont Programmable Torque Verifier FM II, Руководство пользователя

Страница: 11 / 37

Page 9
Chapter 2 - Principles of Operation
Overview
The PTV/Switch Wrench System is designed to assist the manufacturer in closing several loops
in the quality system which have been, until now, gaps in their quality improvement efforts. The
key capabilities this system enables:
1. Ability to integrate hand torque tools into the automated line control system.
2. Process control of the actual torque wrench use process, not just the wrench calibration
process.
3. Rapid and effective training in proper torque wrench use, with reinforcement of proper use
provided with every wrench click.
This chapter will cover the system, starting with the concepts involved in the use of the
Generation II PTV-FM and FM Switch Wrench system, than move to line integration.
Concept Principles
Any and every clicker-type torque wrench can be operated in essentially three ways:
It can be clicked too quickly, or “jerked”.
This can result in either undertorquing because the torque was not transmitted to the fas-
tener, or overtorquing if it was jerked and too much rotation was applied, even though the
time period was very brief.
It can be used properly, with force applied smoothly until the wrench clicked, then the force
immediately released.
When a preset wrench is used, this results in accurate transmission of the preset torque to
the fastener.
It can be pulled past the click.
This results in overtorquing the fastener by rotating it past the point where the correct
torque was attained.
The fact that there are two operator-induced process failure modes in clicker-type torque wrench
use has always been a weak point in their selection as assembly tools. A probability of occur-
rence for each failure mode exists even when the tool is used by a trained, experienced and