49
・
Provide sufficient strength for the draw pipe. If the draw pipe is broken due to
insufficiency of the strength, the gripping force will be lost instantly, which is
dangerous as the work will fly out.
・
Keep the dimension e and the dimension f in Fig. 16 for the draw pipe and
a material with the tensile strength 380MPa (38kgf/mm
2
) or more must be
used.
・
The personnel who designed draw pipe must judge whether the strength of
the draw pipe is sufficient for the usage conditions.
・
The dimensions and materials specified in this manual do not guarantee
that the draw pipe will not break under every usage condition.
・
If the screw-in depth of the draw pipe to the draw nut is insufficient, the screw
will break and the gripping force will be lost instantly, which is dangerous as
the work will fly out.
・
If the engagement of the screw of the draw pipe is loose, vibration may occur
resulting in breakage of the screw. If the screw breaks, the gripping force will
be lost instantly, which is dangerous as the work will fly out.
・
If the draw pipe is unbalanced, vibration occurs, the screw is broken and the
gripping force will be lost instantly, which is dangerous as the work will fly
out.
2. Processing of draw nut
1. Remove the socket head cap screw fixing the plunger nut with a hex key, and take out
the plunger nut and the draw nut together.
2. Remove the draw nut from the plunger nut. At this point, pay attention not to lose the
steel ball (rigid sphere of
φ
5) and the coil spring.
3. Process the draw nut to match the screw of the draw pipe.
4. When assembling, build the draw nut in the plunger nut, turn the draw nut to check the
responsiveness of the steel ball, and then attach it with the hexagon socket head bolt. If
no responsiveness is obtained, assemble it again. Also, tighten the socket head cap
screw at the specified torque (Refer to page 50).
Summary of Contents for QB300
Page 22: ...21 Fig 8 ...
Page 60: ......
