Hitachi C 7UR User manual

C
REPAIR GUIDE ---------------------------------------------------------------------------------------------------------------- 1
1. Precautions on disassembly and reassembly ----------------------------------------------------------- 1
• Disassembly ------------------------------------------------------------------------------------------------------ 1
• Reassembly ------------------------------------------------------------------------------------------------------ 6
• Lubrication points and type of lubricant -------------------------------------------------------------------- 8
• Screw tightening torque --------------------------------------------------------------------------------------- 8
• Checking after reassembly ------------------------------------------------------------------------------------- 9
• Wiring diagram ---------------------------------------------------------------------------------------------------10
STANDARD REPAIR TIME (UNIT) SCHEDULES -------------------------------------------------------------------12
CONTENTS Page
C 7UR
Overseas Sales Division
PRODUCT NAME
Hitachi 184 mm (7-1/4”) Circular Saw
Models C 7UR, C 7BUR *For the USA and Canada only
Hitachi 185 mm (7-1/4”) Circular Saw
Model C 7UR *Except for the USA and Canada
CONFIDENTIAL
Dec. 2017

-1-
• Removal of washer (A)
[26]{26} [11]{11}
[12]{12}
[13]{13}
[14]{14}
[65]{62}
• Removal of the TCT saw blade
[23]{23}
[503]{502}
[14]{14}
[13]{13}
[12]{12}
[16]{16}
CAUTION: During disassembly and reassembly, and at all other times as well, always exercise
sufficient care in handling to ensure that there is no deviation in the bottom surface
flatness of the base or in its perpendicularity relative to the saw blade.
1. Precautions on disassembly and reassembly
[Bold] numbers in the description below correspond to the item numbers in the parts list and exploded
assembly diagram for the Model C 7UR, and {Bold} numbers correspond to those for the Model C 7BUR.
CAUTION: Prior to disassembly of the circular saw, remove the TCT Saw Blade [12]{12} to protect
the saw blade teeth and yourself.
1. Removal of the TCT saw blade
(1) Gently turn the Hex. Socket Hd. Bolt M8 x 15.5 [14]{14} using the accompanying Hex. Bar Wrench 6
mm [503]{502} to lock the Spindle and Gear Set [1]{1} while pushing the Lock Lever [23]{23}.
(2) After locking the Spindle and Gear Set [1]{1}, turn the Hex. Bar Wrench 6 mm [503]{502}
counterclockwise to loosen and remove the Hex. Socket Hd. Bolt M8 x 15.5 [14]{14} and Washer (B)
[13]{13}. Draw the Lever [16] and insert the Lower Guard [8]{8} into the Gear Cover [26]{26} and then
remove the TCT Saw Blade [12]{12}.
NOTE: Be careful not to cut your fingers by the saw blade teeth.
(3) Remove Washer (A) [11]{11} from the Spindle and Gear Set [1]{1}. If the Base Plate [65]{62} interferes
with removing Washer (A) [11]{11}, loosen the Lever [66]{63} and adjust to shallower cutting depth.
REPAIR GUIDE
Disassembly
1
Loosen
2
Push in
3
4 5
6 Draw
Loosen
[66]{63}
Tighten

-2-
• Removal of the lower guard
[26]{26}
[5]{5}
[6]{6}
• Removal of Lever
2. Removal of the lower guard
(1) Remove the two Seal Lock Flat Hd. Screws M4 x 10 [10]{10}, then remove the Bearing Cover [9]{9}.
(2) Remove the hook of the Return Spring [7]{7} from the Gear Cover [26]{26} and the Lower Guard [8]{8},
then remove the Lower Guard [8]{8}, Liner [5]{5} and Washer [6]{6}.
3. Removal of the lever
(1) Loosen the Lever [66]{63} and remove the Retaining Ring (E-type) [58]{55}.
(2) Remove the Lever [66]{63}, Lock Nut [59]{56}, Bolt Washer M8 [60]{57}, and Bolt (Square) M8
[29]{29}.
[7]{7} [8]{8}
[9]{9}
[10]{10}
[58]{55}
[59]{56
}
[66]{63
}
[60]{57}
[29]{29}

-3-
• Separation of the spindle and gear set from the bearing holder
• Removal of the bearing holder and spindle and gear set
[26]{26}
[3]{3}
[2]{2}
[1]{1}
[1]{1}
[2]{2}
4. Removal of the bearing holder and spindle and gear set
(1) After removing the Lower Guard [8]{8} as described above, loosen the two Seal Lock Flat Hd. Screws
M5 x 14 [3]{3}.
(2) Remove the Bearing Holder [2]{2} together with the Spindle and Gear Set [1]{1} from the Gear Cover
[26]{26}.
5. Separation of the spindle and gear set from the bearing holder
(1) Support the Bearing Holder [2]{2} with an appropriate tubular jig.
(2) Push down on the end of the spindle to separate the Spindle and Gear Set [1]{1} from the Bearing
Holder [2]{2}.
Push
Jig
60 mm
(
2-23/64"
)
50 mm
(1-31/32")

-4-
• Disassembly of the motor unit
[26]{26}
Fan
[53]{56}
[34]{32}
[33]{31}
[32]{30}
[23]{23}
[22]{22}
[18]{18}
[17]{17}
[45]{42}
[44]{41}
6. Disassembly of the motor unit
(1) Remove the Brush Caps [45]{42} and take out the Carbon Brushes [44]{41}.
(2) Loosen the Machine Screws M5 x 50 [39]{36} and separate the Housing Ass'y [42]{39} from the Gear
Cover [26]{26}. If the Armature [22]{22} is remained in the Housing Ass'y [42]{39}, gently tap the
Housing Ass'y [42]{39} on the edge of the surface where the Gear Cover [26]{26} is mounted with a
wooden or plastic hammer and remove the Armature [22]{22}.
NOTE: Do not hit the fan of the Armature [22]{22}.

-5-
• Disassembly of handle (A).(B) set
• Removal of the base ass'y
[74]{71}
[42]{39}
[77]{74}
[38]{35}
[48]{45}
[47]{44}
[46]{43}
[51]{46}
[54]{51}
{48}
[56]{53}
[55]{52}
[53]{50}
[52]{49}
[38]{35}
7. Removal of the base ass’y
Extract the Roll Pin D6 x 40 [74]{71} and remove the Base Ass’y [77]{74} from the Housing Ass’y [42]{39}.
8. Disassembly of handle (A).(B) set
(1) Loosen and remove the six Tapping Screws D4 x 20 [38]{35}.
(2) Remove handle (B).
(3) Remove the Switch [48]{45}, Cord [55]{52}, etc. from handle (A).

-6-
[53]{50}
[52]{49} [52]
[53]
• Mounting the cord clip
Protrusion
Other than the USA, Canada, and Mexico
For the USA, Canada, and Mexico
• Mounting the lock lever
[23]{23}
[22]{22}
[33]{31}
[26]{26}
[34]{32}
[32]{30}
Rib
[26]{26}
[23]{23}
Rib
Generally, perform reassembly by reversing the disassembly procedure. However, special attention should
be given to the following items. Refer to “Lubrication points and type of lubricant” on page 8 for the grease
required for reassembly.
1. Reassembly of the power supply unit and its vicinity
Perform wiring according to the wiring diagrams shown on pages 10 and 11 when replacing the Stator Ass'y
[20]{20}, Cord [55]{52}, Noise Suppressor [35] or the Switch [48]{45}. Mount the Cord Clip [53]{50} in the
direction shown in the following figure.
2. Mounting the stator ass'y
Press-fit the Stator Ass'y [20]{20} into the Housing Ass'y [42]{39} so that the internal wire of the Stator
Ass'y [20]{20} is positioned to the opposite side of the name plate on the Housing Ass'y [42]{39}. Refer to
the wiring diagrams on pages 10 and 11. After press-fitting, hook the Brush Terminal [19]{19} on the Brush
Holder [43]{40}.
3. Mounting the lock lever
(1) Mount the O-ring [34]{32} into the Gear Cover [26]{26}. Mount the Lock Lever [23]{23} between the fan
of the Armature [22]{22} and Dust Washer (B) [32]{30}. Mount the Ball Bearing [33]{31} to it. Then
carefully mount this assembly into the Gear Cover [26]{26}.
NOTE: Check that both ends of the flat spring on the Lock Lever [23]{23} are properly supported
by the ribs inside the Gear Cover [26]{26}.
(2) After mounting the Lock Lever [23]{23}, push the Lock Lever [23]{23} by hand and check that it returns
to its original position when released.
Reassembly
Protrusion

-7-
• Mounting the bearing holder
[26]{26}
The Bearing Holder [2]{2} has a protrusion on either left or right side.
Protrusion
Position of the protrusion
4. Mounting the bearing holder
(1) Mount the Bearing Holder [2]{2} to the Gear Cover [26]{26} positioning the protrusion on either left or
right side of the Bearing Holder [2]{2} downward.
NG
NG
OK
OK

-8-
Apply specified amount of grease to the following portions.
Grease (Nippeco BC-4)
• Pinion tooth flank of the Armature [22]{22} ····························································· About 1 g
• Gear tooth flank of the Spindle and Gear Set [1]{1} ·················································· About 2 g
• Inside the gear chamber of the Gear Cover [26]{26}················································· About 6 g
Prepare the following grease as necessary.
Item Registered part name Net weight Code No.
Grease (Nippeco BC-4) Grease (Nippeco BC-4) 75 g 372814
Location Name of screw or bolt No.
used
Tightening torque
N•m kgf•cm
Main body
[2]{2} Bearing Holder [3]{3} Seal Lock Flat Hd. Screw M5 x 14 2 2.7 - 4.1 2.0 - 3.0
[9]{9} Bearing Cover [10]{10} Seal Lock Flat Hd. Screw M4 x 10 2 1.4 - 2.2 1.0 - 1.6
[12]{12} TCT Saw Blade [14]{14} Hex. Socket Hd. Bolt M8 x 15.5 1 7.8 - 11.8 5.8 - 8.7
[16]{16} Lever [15]{15} Machine Screw (W/Washers) M4 x 12 (Black) 1 0.8 - 1.2 0.6 - 0.9
[24]{24} Flow Guide (B) [15]{15} Machine Screw (W/Washers) M4 x 12 (Black) 1 1.4 - 2.2 1.0 - 1.6
[27]{27} Cushion [28]{28} Flat Hd. Screw M6 x 20 1 —*1 —
*1
[40]{37} Tail Cover [38]{35} Tapping Screw (W/Flange) D4 x 20 (Black) 2 1.5 - 2.5 1.1 - 1.8
[46]{43} Cord Holder [38]{35} Tapping Screw (W/Flange) D4 x 20 (Black) 1 1.5 - 2.5 1.1 - 1.84
[56]{53} Handle (A).(B) Set [38]{35} Tapping Screw (W/Flange) D4 x 20 (Black) 5 1.5 - 2.5 1.1 - 1.84
[42]{39} Housing Ass'y [39]{36} Machine Screw (W/Washers) M5 x 50 (Black) 3 2.7 - 4.1 2.0 - 3.0
[43]{40} Brush Holder [41]{38} Hex. Socket Set Screw M5 x 8 2 0.5 - 1.0 0.4 - 0.74
[44]{41} Carbon Brush [45]{42} Brush Cap 2 0.5 - 1.5 0.4 - 0.74
[48]{45} Switch [47]{44} Tapping Screw (W/Flange) D4 x 10 (Black) 2 1.5 - 2.5 1.1 - 1.84
[53]{50} Cord Clip [52]{49} Tapping Screw (W/Flange) D4 x 16 2 1.5 - 2.5 1.1 - 1.84
[57]{54} Lever (A) [59]{56} Lock Nut 1 1.4 - 2.0 1.0 - 1.5
Base ass'y
[66]{63} Lever [59]{56} Lock Nut 1 1.4 - 2.0 1.0 - 1.5
[61]{58} Bevel Stand [63]{60} Seal Lock Flat Hd. Screw M5 x 14 4 2.7 - 4.1 2.0 - 3.0
[72]{69} Step Pin [67]{64} Seal Lock Hex. Socket Set Screw M5 x 6 1 2.7 - 4.1 2.0 - 3.0
[75]{72} Link [76]{73} Seal Lock Flat Hd. Screw M4 x 8 3 1.4 - 2.2 1.0 - 1.6
[69]{66} U-nut M5 [71]{68} Special Bolt 1 2.7 - 4.1 2.0 - 3.0
*1: Tighten the Flat Hd. Screw M6 x 20 [28]{28} until it is flush with the Cushion [27]{27}.
Lubrication points and type of lubricant
Screw tightening torque

-9-
• Check the following after reassembly.
(1) Adjust the base ass’y angle to 90°±0.5° with the Slotted Hd. Set Screw (Seal Lock) M6 x 8 [64]{61}.
(2) Check that the Base Ass’y [77]{74} operates smoothly. (Adjust the cutting depth and tilt angle.)
(3) Check the switch operation.
(4) Check that the Lower Guard [8]{8} moves smoothly and returns within the operating range (maximum
to minimum cutting depth, tilt angle of 0° to 55°) of the Base Ass’y [77]{74}.
(5) Check the insulation resistance and dielectric strength voltage.
Insulation resistance: 7 MΩor higher with DC 500 V megohm tester
Dielectric strength: AC 4,000 V/1 minute, with no abnormalities
(6) Check that runout of the saw blade is up to 0.7 mm at 160 mm dia. position.
(7) Check that the direction indicated by the arrow mark on the TCT Saw Blade [12]{12} matches that of the
arrow mark on the Gear Cover [26]{26}.
(8) Perform checking according to the handling instructions.
• Cleaning the cover
Clean the exterior of the tool with a soft cloth moistened with soapy water, and dry thoroughly. Do not use
chloric solvent, gasoline, and thinner for cleaning. Otherwise, the plastic components may be melted.
Checking after reassembly