Automatic Needle Threading (Trouble And Corrective Measure) - ELNA E9020 Service Manual

Automatic needle threading (trouble and corrective measure)

Trouble
1
Needle thread comes off the
thread retaining section when
the transfer body rotates and
comes down.
2
Thread fails to pass the needle
eyelet.
3
Thread is not caught by the
-1 needle clamp thread guide.
Needle thread fails to enter the
fork end.
Needle thread
3
The needle clamp thread guide
-2 fails to catch thread.
Thread deflects to the inside of
the thread guide and cannot be
caught.
3
The needle clamp thread guide
-3 fails to catch thread.
Thread deflects to the outside
of the thread guide and cannot
be caught.
The set needle thread does not enter up
(a)
to the root of shaft and is narrowly retained
at the top end.
The retaining pressure does not become high.
(b)
Turn OFF the power, and turn the driving shaft
counterclockwise. The retaining pressure change-
over plate works and the spring is compressed to
increase the retaining pressure.
Height of the threading hook is improper.
(a)
Thread tensed in front of needle is not in the center of needle eyelet at the
(b)
lower position of the transfer body.
Longitudinal position of the transfer body in terms of needle is not proper at
(c)
the lower position of the transfer body.
Thread retaining section is open at the lower
(d)
position of the transfer body.
The base tension is open when threading.
(e)
The base tension is open when threading.
(a)
The position of needle clamp threading arm is too high.
(b)
The transfer body is attached to the left side.
(c)
Longitudinal position of the transfer body is
(d)
improper. Front and rear
The transfer body is attached to the left side.
(a)
(b) The position of needle clamp threading arm is too high.
The thread path control plate is attached to the left side.
(c)
The transfer body is attached to the right side.
(a)
The position of needle clamo threading arm is too low.
(b)
(c) The thread path control plate is attached to the right side.
Cause
Front and rear
Corrective measure
Adjust the retaining pressure at the upper position referring to
(24)-1-3).
When the spring is not compressed, check the adjustment of the
retaining pressure change-over link referring to (24) -2-4).
Check the adjustment of the needle threader referring to (23).
Check the vertical adjustment of the lower position referring to
(24)-2-3).
Check the longitudinal adjustment of the lower position referring
to (24)-2-2).
Check the adjustment of the retaining pressure change-over link
referring to (24)-2-4.
Check the adjustment of the base tension referring to (8).
Check the adjustment of the base tension referring to (8).
Check the adjustment of the height of needle clamp threading
arm referring to (24)-3.
Check the lateral adjustment of the transfer body referring to
(24)-4.
Check the longitudinal adjustment of the lower position referring
to (24)-2-2).
Check the lateral adjudstment of the transfer body referring to
(24)-4.
Check the adjustment of the height of needle clamp threading
arm referring to (24)-3.
Adjust the thread path control plate referring to (24)-5.
Check the lateral adjustment of the transfer body referring to
(24)-4.
Check the adjustment of the height of needle clamp threading
arm referring to (24)-3.
Adjust the thread path control plate referring to (24)-5.
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