Hitachi NV 90HMC, Technical Data And Service Manual

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3. Disassembly and reassembly of the Piston Bumper, Feeder (A), Feed Piston, etc
(1) Disassembly
• Remove the Nose [47] and push the lever components from the output section according to item 1 in
"Disassembly and Reassembly of the Nail Feeder Section". You can then remove the Piston Bumper
[45] .
• Remove the Retaining Ring For D24 Hole [114] by using the C-shaped snap ring puller for the hole, while
pressing the Feed Piston Cover [113] with your finger so that it does not pop up. You can then remove the
Feed Piston Cover [113] , Bumper [112] , Feed Spring (A) [110] , and Feed Spring (B) [111] .
• Pull out the Roll Pin D4 x 18 [51] by using the roll pin puller (ø 4). You can then remove the Feed Piston
[109] and Feeder Arm (B) [52] .
• Push out the Plunger (B) [55] by using the roll pin puller (ø 4). You can then remove Feeder (A) [54]
and the Feeder Spring [53] from Feeder Arm (B) [52] .
(2) Reassembly
Conduct reassembly by reversing the disassembly procedure, but note the following:
• If the air passages of the Body Ass’y [42] and Nose [47] and the feed piston chamber become clogged
with broken pieces of the Piston Bumper [45] or other objects, the Feed Piston [109] may not work
properly. So, when replacing the Piston Bumper [45] , clean these parts prior to reassembly.
• Apply grease to the O-Ring (P-9) [107] and Feed Piston O-Ring [108] prior to reassembly.
• Apply grease to the groove of the Feed Piston [109] .
• Assemble the Bumper [112] with its stepped part on the Feed Piston [109] side.
• Grease must be applied to the sliding parts of the Feed Piston [109] and O-Ring of the Nose [47] prior
to reassembly. However, too much grease on Surface A will adversely affect Feed Piston [109]
movement (at low air pressure).
• Assemble the Roll Pin D4 x 18 [51] with its split side on the magazine side as shown above. After
reassembly, the amount of protrusion at both ends must match (at 1 to 1.3 mm).
• Make sure the Retaining Ring For D24 Hole [114] is just in the groove of the Nose [47] .
Piston Bumper [45]
Body Ass'y [42]
Nose [47]
Feeder Arm (B) [52]
Feed Piston [109]
O-Ring (P-9) [107]
Roll Pin D4 x 18 [51]
Retaining Ring For
D24 Hole
[114]
Feed Piston Cover [113]
Feed Piston O-Ring (I.D. 14) [108]
Roll Pin D4 x 18 [51]
Feeder Arm (B) [52]
Split side
Groove Stepped Groove
Magazine side
Surface A
Feed piston chamber
Amount of protru
sion:
1 to 1.
3 mm
• Disassembly and reassembly of Piston Bumper, Feeder (A), Feed Piston, etc