Hitachi NEXT Series Service Manual page 41

4.16.3 Cleaning and Checking
① Clean the STV body. In particular, sand the valve
seat surface with sandpaper until the machining
surface is visible.
② Check the sliding surface in the air cylinder tube,
and if there is r ust, finish the sur face with a
sandpaper of #1000 or equivalent.
③ If the sliding surface on the outer diameter of the
spindle is rusted, finish it with a sandpaper of #150
or equivalent.
④ Finish the outer surface of the STV valve plates with
sandpaper until the machining surface is visible.
⑤ Clean the groove for the seal packing, etc. with a wire
brush.
After cleaning, wipe off the oil from all the parts.
4.16.4 Assembling
① Attach seal packing (1) and (2) (515 and 516,
respectively), to the inner surface of the air cylinder
cover (504). (Fig. 3) Attach air cylinder O-ring (520)
to the outer sur face of the cover (504). (Fig. 4)
Attach seal packing (4) and (5) (519 and 521,
respectively), to the inner surface of the air cylinder
cover 1 (504). Attach air cylinder O-ring (540) and
valve gasket (550) to the outer surface the cover 2
(505). Attach rod metal (510). Apply specified
grease to the seal packing grooves in advance.
Specified grease: Daphne Coronex No.1 (approx. 0.1oz(3 g))
(515) (516) (522)
Fig.3 Cover (1) (504)
(540) (504) (519)
(520) (522)
(510)
Fig.4 Cover (2) (505)
(504)
(520)
(550) (521)
Confidential to Customer
② Fit seal packing (3) (518) to piston (517). Then
attach air cylinder piston gasket (537) to spindle
(509). (Fig .5)
③ Attach a key (541) to the spindle, and then mount
the piston (517) and snapring (537).
(517)
(509)
(F27)
Fig.5 Air cylinder piston (517)
④ Attach air cylinder cover 1 (504), cover 2 (505) on both
sides of air cylinder tube (503). When attaching, check
the matching mark so that the direction is correct.
⑤ Attach a backup ring (F28).
(F28)
(504)
⑥ Attach air cylinder cover (526) to the seal packing
(515) and O-ring (spacer) (540). After that, attach
into cover 1 (504), tying rod (525), wave spring (536)
and nut (535).
(515)
Fig.6 Air cylinder piston (526)
(526)
39
(518) (537) (541)
(503)
(505)
(540)
(504)
(536)
(525)
(535)