Hitachi H 30PV, Технические данные и руководство по обслуживанию

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8. REFERENCE INFORMATION
Structure:
Fig. 2
8-1. Striking Operation
The rotation of the armature is transferred to the crank shaft and connecting rod, which in turn cause the piston to
reciprocate inside the cylinder. As the piston reciprocates, the changing air pressure inside the air chamber
between the piston and the striker causes the striker to continuously strike against the end of the second hammer.
At the same time, the air-cushion effect within the air chamber absorbs the impact of the second hammer. Should
the air escape from the air chamber, the air-cushion effect would cease, and the impact energy would not be
absorbed. Accordingly, the O-rings mounted on the striker and piston play an extremely important role in sealing
the air within the air chamber.
Second hammer
Crank case cover
Cylinder
Air chamber
Connecting rod
Piston
O-rings
Striker
Armature
Crank shaft
8-2. Idling-proof Mechanism
When the bull point is released from the concrete surface, the second hammer moves to the position illustrated in
Fig. 3, and the sleeve moves out of striking position. When this occurs, the air holes are opened and the pressure
within the air chamber remains unchanged even though the piston continues to reciprocate, thereby preventing
striking operation.