FEC AFC1500 User Manual

Page 91

FEC AFC1500 Operations Manual

Chapter 6: Fastening Instructions (Rev. 6: 10/09)

Page 6-5

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Three-Step Fastening

Three-step fastening will be used primarily for joints that have a requirement to synchronize with

another spindle during the incremental stages of the rundown to crush/compress a gasket or grom-
met or for special joint conditioning (valve cover, oil pan, or body assembly, for example).

1. The system will fasten to the 1ST TORQUE value during the specified 1ST TIME. 1ST

TORQUE must be reached within the 1ST TIME limits or a reject will occur.

2. Once SPEED CHANGE TORQUE is reached or FREERUN REVOLUTIONS expires, the sys-

tem will switch from FREERUN SPEED to SLOWDOWN SPEED and continue to fasten to
1ST TORQUE.

3. Upon reaching 1ST TORQUE, 1ST TIME ends and FINAL TIME begins. 1ST TORQUE is

the shift point to TORQUE SPEED and the synchronization point prior to commencing the
next step. (See 4.7.6 for Standalone Sync. info)

4. The system will fasten to CROSSOVER TORQUE, synchronize with other spindles and then

fasten to STANDARD TORQUE using TORQUE SPEED during FINAL TIME. STANDARD
TORQUE must be reached within the FINAL TIME limits or a reject will occur.

FUNCTION

RECOMMENDATION / COMMENT

SPEED CHANGE TORQUE

10% of STANDARD TORQUE

THRESHOLD TORQUE

Start point of 1

torque rate monitoring (section 6.2)

1ST TORQUE

30% of STANDARD TORQUE
Used for RATE/TIME settings and TORQUE SPEED initiation.
Synchronization point for 2nd STEP

SNUG TORQUE

Angle Monitoring Start Point (section 6.2)

CROSSOVER TORQUE

Start point of 3

torque rate monitoring (section 6.2)

Synchronization point for 3rd STEP

STANDARD TORQUE

Engineered product fastening specification

1ST TIME HIGH/LOW LIMIT

Acceptance range to reach 1ST TORQUE setting

FINAL TIME HIGH/LOW LIMIT

Acceptance range to go from 1ST TORQUE to STANDARD
TORQUE

FIG. 6-1-1c Torque Control Functions for Three-Step Fastening

Standard Torque

Threshold Torque

Speed Change Torque

Torque

Crossover Torque

Time

Final Time

Snug Torque

Torque

Angle/Time