Hitachi DH 40MRY HOW to Handle a Core BIT, HOW to Replace Grease, Maintenance and Inspection

English

CAUTION:

During operation, be sure to grip the handle and the side handle firmly to prevent your body from swaying.

(1)Switching to “rotation + hammering”

For switching to “rotation + hammering”, follow the same procedures mentioned in [3. When drilling at “rotation + hammering”].

(2)Attaching chuck adapter to drill chuck (Fig. 14)

(a)Attach the chuck adapter to the drill chuck.

(b)The SDS max shank of the chuck adapter is equivalent to the drill bit. Therefore, follow the same procedure as [How to install tool] for attaching and detaching.

(3)Drilling

(a)Even if you apply more-than-required pressure to the machine body, drilling can never be performed as quickly as you expect. Applying more force or pressure to the machine body than what is needed, on the contrary, damages the drill tip, resulting in the declined working efficiency and shortened life of this machine.

(b)A drill can snap sometimes when drilling is almost finished. It is important to relax your thrusting pressure when drilling is nearing the end.

HOW TO HANDLE A CORE BIT

When a core bit is used, large diameter holes and blind holes can be drilled. In this case, use optional accessories for core bits (such as a center pin and core bit shank) for more efficient operation.

1. Mounting

CAUTION:

Prior to mounting a core bit, always disconnect the plug from the power supply receptacle.

(1)Mount the core bit on the core bit shank. (Fig. 15) Before that, feed oil to the screw portion of core bit shank for easy dismounting.

(2)Mount the core bit shank on the main body in the same manner as in mounting the drill bit and the bull point. (Fig. 16)

(3)Insert the center pin into the guide plate until it reaches the extremity.

(4)Fit in the guide plate by aligning its concaved portion with the core bit tip. When the position of the concave is shifted by turning the guide plate right or left, the guide plate never slips off even

when the drill is used in a downward direction. (Fig. 17)

2. Drilling holes

(1)Insert the plug into a receptacle.

(2)A spring is built in the center pin. By straightly and gently pressing it to the wall or floor surface, the entire surface of the core bit tip attains contact to start the hole drilling job. (Fig. 18)

(3)When the hole depth reaches approximately 5 mm, the hole position can be determined. Then remove the center pin and guide plate from the core bit and continue the hole drilling job.

CAUTION:

When removing the center pin and guide plate, always disconnect the plug from the receptacle.

3. How to dismount the core bit

◯By holding the rotary hammer (with the core bit inserted) in an upward position, drive the rotary

hammer to repeat impact operation two or three times, whereby the screw is loosened and the rotary hammer becomes ready for disassembly. (Fig. 19)

◯Remove the core bit shank from the rotary hammer, hold the core bit with one hand, and strongly strike the head of the SDS max shank portion of the core bit shank with a manual hammer two or three times, whereby the round head screw is loosened and the rotary hammer is ready for disassembly. (Fig. 20)

HOW TO REPLACE GREASE

This machine is of full air-tight construction to protect against dust and to prevent lubricant leakage. Therefore, the machine can be used without lubrication for long periods. Replace the grease as described below.

1.Grease replacement period

After purchase, replace grease after every 6 months of usage. Ask for grease replacement at the nearest Hitachi Authorized Service Center. Proceed for replacement of grease.

2.Grease replenishment

CAUTION:

Before replenishing the grease, turn the power off and pull out the power plug.

(1)Remove the crank cover and wipe off the grease inside. (Fig. 21)

(2)Supply 30 g of Hitachi Electric Hammer Grease A (Standard accessory, contained in tube) to the crank case.

(3)After replenishing the grease, install the crank cover securely.

NOTE:

The Hitachi Electric Hammer Grease A is of the low viscosity type. If necessary purchase from an Hitachi Authorized Service Center.

MAINTENANCE AND INSPECTION

1.Inspecting the tool

Since use of a dull tool will degrade efficiency and cause possible motor malfunction, sharpen or replace the tool as soon as abrasion is noted.

2.Inspecting the mounting screws

Regularly inspect all mounting screws and ensure that they are properly tightened. Should any of the screws be loose, retighten them immediately. Failure to do so could result in serious hazard.

3.Maintenance of the motor

The motor unit winding is the very “heart” of the power tool. Exercise due care to ensure the winding does not become damaged and/or wet with oil or water.

4.Inspecting the carbon brushes (Fig. 22)

The Motor employs carbon brushes which are consumable parts. When they become worn to or near the “wear limit”, it could result in motor trouble. When an auto-stop carbon brush is equipped, the motor will stop automatically. At that time, replace both carbon brushes with new ones which have the same carbon brush Numbers shown in the figure. In addition, always keep carbon brushes clean and ensure that they slide freely within the brush holders.

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