DH 20PB
Contents
1. 10 EAS AE u u u annassa ass 10 9 2 018 i C ed 10 8 3 Rotation Only and Rotation Striking Changeover Mechanism 13 9 4 Hotauon ONY NOESTE ER a eue 14 m m 15 8 6 GHhuck 16 DST DONC CIOR uuu nuusan 16 9 PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY 18 9 1 Disassembily RR TE 18 PCM y u u uuu 20 S LUDIC ION TEE I EU 20 Sp Mese E c sas 20 9 5 Wiring DIagrami uu nue td a ERR da bu iaraa lidad I beue iik va 20 9 6 Internal Wire Arrangement and Wiring Work 4 21 GES TOS u u 22 1040 Current ValUBS eee stus 22 10 STANDARD REPAIR TIME UNIT SCHEDULES 23 Assembly Diagram for DH 20PB 1 PRODUCT NAME Hitachi Hammer Drill variable speed and reversing Model DH 20PB 2 MARKETING OBJECTIVE The Model DH 20PB has been developed based on the Model DH 24PB inheriting the reliable strikin2. 306 369 OPTIONAL ACCESSORIES MO CODE NO DESCRIPTION Rem DRILL BIT SLENDER SHAFT D3 4X90 306 368 DRILL BIT SLENDER SHAFT D3 5X90 306 370 ADAPTER FOR SLENDER SHAFT SDS PLUS 944 460 TAPER SHANK DRILL BIT D11X100 944 461 993 038 TAPER SHANK DRILL BIT D12 3X110 TAPER SHANK DRILL BIT D12 7X110 944 462 TAPER SHANK DRILL BIT D14 3X110 944 500 TAPER SHANK DRILL BIT D14 5X110 944 463 TAPER SHANK DRILL BIT D17 5X120 944 464 303 617 TAPER SHANK DRILL BIT D21 5X140 TAPER SHANK ADAPTER SDS PLUS NO 1 303 618 TAPER SHANK ADAPTER SDS PLUS NO 2 303 619 A TAPER SHANK ADAPTER SDS PLUS 303 620 B TAPER SHANK ADAPTER SDS PLUS 944 477 303 332 COTTER HAMMER DRILL CHUCK SET 13MM INCLUD 617 618 303 334 CHUCK HANDLE 303 335 RUBBER CAP 302 976 ANCHOR SETTING ADAPTER A SDS W1 4X260L 302 975 303 621 ANCHOR SETTING ADAPTER A SDS W5 16X260L ANCHOR SETTING ADAPTER A SDS W3 8X160L 302 974 ANCHOR SETTING ADAPTER A SDS W3 8X260L 302 979 ANCHOR SETTING ADAPTER B SDS W1 4X260L 302 978 ANCHOR SETTING ADAPTER B SDS W5 16X260L 303 622 302 977 ANCHOR SETTING ADAPTER B SDS W3 8X160L ANCHOR SETTING ADAPTER B SDS W3 8X260L 971 794 ANCHOR SETTING ADAPTER A W1 4 MANUAL 971 795 ANCHOR SETTING ADAPTER A W5 16 MANUAL 971 796 ANCHOR SETTING A
3. Section of the chuck section Fig 4 The service life of a drill bit with a diameter of 8 mm is approximately 300 holes when drilling into concrete with a depth of 30 mm If reground before the end of its service life the drill bit will continue to provide efficient drilling Fig 5 shows the regrinding angle Regrinding angle of drill bit Rotation direction 60 Section A B Fig 5 5 8 6 Chuck Section Fig 6 shows the construction of the chuck section Steel ball Washer B Front cap Grip Forward 72 lt Backward 4 onu y Cylinder Key rails two pieces Ball pines Fig 6 The opening where the drill bit is inserted is covered with a front cap rubber to prevent dust from entering inside When the drill bit is inserted the steel ball fits into the matching groove on the drill bit to lock it in place and prevent it from falling out Two key rails transmit rotating torque to the drill bit The drill bit can be released by simply pulling the grip back The grip is held forward by a holder spring To mount a drill bit pull the grip back to compress the holder spring The steel ball then moves outward While turning the drill bit push it until it makes contact and is fully inserted Then release the grip so that it moves forward and fixes the drill bit To remove the drill bit simply pull the grip back fully and pull the drill bit out 8 7 Dust Collector B While drilling hol
4. Glassfiber reinforced polyamide resin green Enclosure Handle cover Gear cover Glassfiber reinforced polyamide resin black Net 2 3 kg 5 1 lbs Weight Gross 4 6 kg 10 1 Ibs Packaging Corrugated cardboard box with case Standard accessories Weight excludes cord and side handle 5 2 Optional Accessories A Drilling anchor holes rotation striking e Drill bit slender shaft ZE HT S 1 Drill bit slender shaft 2 Adapter for slender shaft SDS plus shank Drill bit Tos shaft EE for slender shaft 3 4 m 1 25 32 90 3 17 32 306369 er 3 5 9 64 1 25 32 90 3 17 32 306368 e Drill bit taper shank SOO ss 1 Drill bit taper shank 2 Taper shank adapter 3 Cotter SDS plus shank 1 Drill bit taper shank 2 Taper shank adapter 3 Cotter Outer dia mm 11 7 16 944460 12 3 31 64 944461 12 7 1 2 993038 Morse taper 944477 14 3 9 16 944462 No 1 14 5 73 128 944500 17 5 11 16 944463 303619 Taper shank adapter A taper or B taper is provided as an 303620 optional accessory but drill bit is not provided 13 mm Hammer drill chuck For drilling operations when using a straight shank bit for impact drilling with a hammer drill eso 9 P Straight shank bit for 13 mm 1 2 hammer drill Chuck wrench impact drills chuck SDS plus shank 13 mm 1 2 hammer drill chuck including chuck wrench 303332 Chuck wrench 33334
5. MODELS DH 20PB HITACHI POWER TOOLS TECHNICAL DATA HAMMER DRILL AND DH 20PB SERVICE MANUAL LIST No E462 Feb 2002 SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT REMARK Throughout this TECHNICAL DATA AND SERVICE MANUAL a symbol s is are used in the place of company name s and model name s of our competitor s The symbol s utilized here is are as follows Competitors Symbols Utilized Company Name Model Name CONTENTS UM PRODUCT NAME de hice ee acta 1 2 MARKETING OBJECTIVE ea as 120 Dirk naar te 1 en aan ete ce at 1 SELLING POINTS a aa a HIE 2 Aol SOIN Bc eie PRU oU MT 2 5 SPECIFICATIONS u CIC AMONG uuu 5 2 q LAGO SOS 4 6 COMPARISONS WITH SIMILAR PRODUCITS J T J J 9 6 1 Specification COMPArISONS lt 0 000sccnccnecececadeiessestaseseececeesenesdecedesdaneceseuedscesesacecesdeesancnsevsseeceserteseeds 9 6 2 Drilling Speed Comparisons ccccccsseeeccceeeseeeeeceeeeeeeeeseeeeeeseueseceeeesueeeeeeesssaeeeeessssaeeeeeesssaageeeeees 9 7 PRECAUTIONS IN SALES PROMOTION J 10 fel Handling S ESO NS NET 10 8 REFERENCE MATERIALIA Z L ao lltl
6. Rubber cap m B Anchor setting e Anchor setting bar to permit anchor setting operation with the hammer drill Anchor setting bar Anchor setting adapter SDS plus shank W 1 4 anchor setting adapter 302976 1 4 anchor setting adapter B 302979 W 5 16 anchor setting adapter A 302975 W 5 16 anchor setting adapter B 302978 W 3 8 anchor setting adapter W 3 8 anchor setting adapter 303622 W 3 8 anchor setting adapter 302974 W 3 8 anchor setting adapter B 302977 Internal cone type External cone type e Anchor setting bar for manual anchor setting Anchor setting adapter W 1 4 anchor setting adapter A 971974 W 1 4 anchor setting adapter 971799 W 5 16 anchor setting adapter A 971795 W 5 16 anchor setting adapter B 971800 W 3 8 anchor setting adapter A 971796 W 3 8 anchor setting adapter B 971801 W 1 2 anchor setting adapter A 971797 W 1 2 anchor setting adapter B 971802 W 5 8 anchor setting adapter A 971798 W 5 8 anchor setting adapter 971803 Internal cone type External cone type C Large hole boring rotation striking e Center pin core bit core bit shank and guide plate AUN er diLE IM Guide plate Center pin Core bit Core bit shank SDS plus shank 1 Center pin Do not use bit with outer diameter of 25 mm 31 32 and 29 mm 1 5 32 Center pin bit outer di
7. Hitachi DH 20PB 318 mm 12 17 32 B 334 mm 13 5 32 The Model DH 20PB with gun type handle has the same striking mechanism as the Model DH 24PB equipped with receiprocating bearing The overall length is significantly reduced 2 Fast drilling speed The drilling soeed of the Model DH 20PB is 40 faster than B 10 slower than the Model DH 24PB as the Model DH 20PB has great striking energy owing to the optimally designed rotation speed striking frequency and weight of the striker 3 Powerful motor The motor of the Model DH 20PB is more powerful than B because it is efficiently cooled in the same manner as the Model DH 24PB 4 Variable speed control switch with superior dust protection and operability The variable speed control switch allows the rotation speed to be changed freely throughout the drilling operation This permits easy centering and positioning and ensures more effective drilling into fragile materials such as tile and brick 5 Equipped with reversing switch By utilizing the newly designed optional accessory chuck adapter and appropriate driver bits and through the combined functions of the variable speed control switch and reversing switch the Model DH 20PB can be used to tighten and loosen a variety of screws 5 SPECIFICATIONS 5 1 Specifications Capacity Concrete 3 4 20 mm 1 8 13 16 13 mm 1 2 32 mm 1 1 4 Voltage current and input Rotation No load FulHoad Housin
8. the Holder Spring 4 Washer B 5 and the Steel Ball D7 0 18 can then be removed from the Cylinder 20 Grip 2 Fig 8 18 3 Disassembly of the cylinder second gear slip mechanism section and related parts Take the Inner Cover 33 off from the Gear Cover 7 and remove the entire chuck section Extract the Retaining Ring for D20 Shaft 6 For easy removal of this retaining ring use of Special Repair Tool J 200 Snap Ring Pliers Code No 970976 is recommended Then turn the Gear Cover 7 upright and use a hand press to extract the Cylinder 20 from the Gear Cover 7 The Sleeve 15 can then be extracted from the Cylinder 20 At this time be very careful not to lose the three Steel Balls D5 556 19 Remove the Retaining Ring for D30 Shaft 24 from the upper part of the Cylinder 20 The Second Gear 21 Spring A 22 and Washer A 23 can then be removed from the Cylinder 20 Then extract the O Ring 1 0 10 5 27 from the inner part of the Cylinder 20 and the Second Hammer 25 can be extracted from the Cylinder 20 For easy extraction of this O Ring 1 0 10 5 27 fit a Special Repair Tool J 201 Spring Hook Code 970977 onto the outer circumference of the O Ring 1 0 10 5 27 and pull it out As the O Ring 1 0 10 5 27 is employed to prevent idle striking please advise customers to replace it with a new one whenever it is disassembled Extract the Retaining Ring for D37 Hole 1
9. 930 515 981 122 303 623 950 272 CHUCK ADAPTER G SDS PLUS DRILL CHUCK 13VLA INCLUD 659 303 624 CHUCK ADAPTER D SDS PLUS 971 5112 DRIVER NO 2 25L 971 5122 DRIVER BIT A NO 3 25L 306 885 306 910 DUST COLLECTOR B ASS Y SOCKET ADAPTER B INCLUD 667 971 787 DUST CUP 931 844 STOPPER 981 840 GREASE A FOR HAMMER HAMMER DRILL 30G 308 471 GREASE FOR HAMMER HAMMER DRILL 70G GREASE FOR HAMMER HAMMER DRILL 500G SERVICE KIT DH 24PB INCLUD 1 9 12 14 18 19 26 27 29 62 672 980 927 320 612 DRILL CHUCK AND ADAPTER SET SDS PLUS INCLUD 658 661 DRILL CHUCK 13VLR INCLUD 659 660 CHUCK WRENCH 10G SPECIAL SCREW M6X22 ALTERNATIVE PARTS 5 DH20PB ITEM NO CODE NO DESCRIPTION zB Printed in Japan 2 02 020205N Hitachi Koki Co Ltd Tokyo Japan
10. D SDS plus shank Grease for electric impact drill Containing 500 g 1 1 Ibs Code No 980927 lt e Containing 30 g 0 07 Code No 981840 70 g 0 15 Ibs Code No 308471 Dust cup Dust collector B ass y Code No 971787 Code No 306885 J Dust cup dust collector B L 6 COMPARISONS WITH SIMILAR PRODUCTS 6 1 Specification Comparisons Capacity Concrete 20 13 16 24 15 16 20 13 16 Steel 13 1 2 13 1 2 Wood 32 1 1 4 32 1 1 4 No load rotation speed 0 1 000 0 1 050 0 1 100 334 13 5 32 360 14 3 16 185 7 9 32 185 7 9 32 205 8 1 16 72 2 27 32 72 2 27 32 79 3 1 8 Note 1 Mark Equipped 2 Weight excludes cord and side handle Dimensions Length mm 318 12 17 32 318 12 17 32 6 2 Drilling Speed Comparisons Drilling speed depends on the operating conditions The test results shown in Fig 1 are based on actual factory tests and are used as a reference only Fig 1 shows the drilling speed comparisons for downward drilling The drill bits used are the Hitachi genuine SDS plus shank bits Sai Pressing force 10 kgf Test material Concrete panel with a compression strength of 240 kgf cm NE boe dier sd al Drilling speed mm min Drill bit dia mm Fig 1 Drilling speed comparisons downward drilling 9 7 PRECAUTIONS IN SALES PROMOTION In the interest of promoting the safest and most ef
11. advised to always wear protective glasses When dust collector B is disassembled for repair or maintenance be very careful to prevent oil or grease from adhering to the steel balls Grease or oil on the steel balls may cause concrete dust to enter the unit and cause defective rotation 16 Dust cover Approx 72 mm 2 27 32 Approx 16 mm 5 8 RE 2 the main body side mum mi un Drill bit length 166 mm 4 quem en Drill bit length 110 mm sel AL TY Socket adapter B _Seal cover _ Socket Retaining ring for D30 shaft Outer race Washer D6 35 steel ball Fig 7 Dust collector B structure a 9 PRECAUTIONS IN DISASSEMBLY AND REASSEMBLY The Bold numbers in the descriptions below correspond to the item numbers in the Parts List and exploded assembly diagram 9 1 Disassembly 1 Disassembly of the Striking Mechanism Section e With a drill bit or screwdriver bit push in the Second Hammer 25 to release the Striker 28 from the O Ring 1 0 10 5 27 e Set the Change Lever 13 to a position halfway between the Drill and Hammer marks on the Gear Cover 7 insert a small flat blade screwdriver into the concave position located on the rear end of the Change Lever 13 and pull it off It is very important to ensure that the Change Lever 13 is positioned halfway between the Drill and Hammer marks when it is disassembled or asse
12. forward the striker slips out of striking position to open up an air vent and stop striking operation and Rotation Only operation is automatically obtained However since the Models DH 24PA and DH 24PB are equipped with a change lever for changeover between Rotation Striking and Rotation Only functions merely mounting the chuck adapter will not stop the striking action it is absolutely necessary to turn the change lever to the Rotation Only setting for drilling or driving screws Should the change lever be set to the Rotation Striking position when the tool is used for drilling the striking action may cause the drill chuck to be broken or damaged Sales personnel should carefully ensure that the buyer is thoroughly advised on this point EN eee 8 5 Drill Bits The chuck section is designed exclusively for the popular and widely available SDS plus shank bits as shown in Fig 4 Rotating torque is transmitted to the drill bit by two key rails provided in the tool holding section A steel ball is used to prevent the bit from falling out Compared with the conventional structure that uses two needle rollers to both transmit rotating torque and prevent the bit from falling out this new structure reduces damage to the shank of the drill bit and extends the service life of the chuck section Key slot two pieces Section A A Shape of SDS plus shank bit Key two pieces Steel ball Ball holder Cylinder
13. second gear idles and does not transmit rotation Even should the drill bit come in contact with a reinforcing bar within the concrete causing sudden excessive torque the slip mechanism functions to prevent damage to the gears and possible loss of control of the tool by the operator Sealed and dustproof construction The gear cover is totally enclosed by oil seals o rings and other devices to prevent leakage of lubricating grease and to keep dust and dirt out into the internal mechanisms The drill bit chuck portion is protected by a rubber front cap to keep out dust and chips which could cause improper fitting of the drill bit and or other faulty operation of the chuck portion The speed control switch is also fully dust proofed type to prevent dust and chips from entering the handle section and causing possible operational trouble or a breakdown of the insulation Speed control The Model 20PB is equipped with a variable speed control switch which permits free change of the rotation speed and striking force When drilling fragile materials pull the switch trigger gently for low rotation speed striking force to achieve optimum results 8 3 Rotation Only and Rotation Striking Changeover Mechanism The change lever on the Model DH 20PB permits quick and easy changeover between the Rotation Only and Rotation Striking functions Armature rotation is transmitted to the second shaft and first gear and then to the clutch via
14. 7 turn the Gear Cover 7 so that its tip portion is upward and use a hand press to extract the Ball Bearing 6904DDPS2L 16 from the Gear Cover 7 Next turn the Gear Cover 7 over and use the hand press to extract the Oil Seal 14 from the Gear Cover 7 Ensure that the Oil Seal 14 is replaced with a new one whenever it is disassembled Use of Special repair tools Snap ring pliers J 200 See Fig 9 Used to remove the Retaining Ring for D20 Shaft 6 which fixes the Cylinder 20 at the tip end of the Gear Cover 7 e Spring hook J 201 See Fig 10 Used to extract the O Ring 1 0 10 5 27 inserted at the inner part of the Cylinder 20 which is designed to catch and grip the striker to prevent idle hammering As shown in Fig 11 fit the Spring Hook J 201 onto the o ring from its outer circumference and pull it out 140 21 2 Spring Hook Code No 970977 Fig 10 1 Snap ring pliers J 200 Code No 970976 Fig 9 J 201 Spring hook O Ring 1 0 10 5 27 Cylinder 20 Fig 11 9 2 Reassembly Perform reassembly in the reverse order of disassembly while observing the given precautions and taking care of the following points 1 To make reassembly easier coat grease on the Steel Balls 11 18 19 2 Reassembly of the Change Lever 13 With a flat blade screwdriver or similar tool move the Clutch 38 and the Reciprocating Bearing 40 so th
15. ATOR 110V 115V 49 340 398F STATOR 230V 240V 2 41 2 ALTERNATIVE PARTS 2 02 PARTS DH20PB TE coveno oescaenon mme O 314 914 INTERNAL WIRE A BLACK 314 913 INTERNAL WIRE A GRAY 608 VVM BALL BEARING 608VVC2PS2L 314 889 HOUSING 314 912 NAME PLATE INTERNAL WIRE A RED 314 915 INTERNAL WIRE A WHITE 301 653 TAPPING SCREW W FLANGE D4X20 BLACK 314 891 HANDLE COVER 314 916 314 921 SPEED CONTROL SWITCH 2P 100V 115V SPEED CONTROL SWITCH 2P 220V 240V 994 273 NOISE SUPPRESSOR 302 488 EARTH TERMINAL 999 041 CARBON BRUSH 1 PAIR 999 072 955 203 CARBON BRUSH AUTO STOP TYPE 1 PAIR BRUSH HOLDER HITACHI LABEL 981 373 TUBE D 315 147 DUST PACKING 314 922 314 923 CHOKE COIL A BLUE CHOKE COIL A BROWN 984 750 TAPPING SCREW W FLANGE D4X16 937 631 CORD CLIP 953 327 CORD ARMOR 08 8 O 55 56 57 58 59 59 60 61 62 62 63 64 65 66 67 68 69 70 71 72 72 500 3902 500 4402 CORD CORD CORD ARMOR D8 8 CORD ARMOR D8 8 FOR GBR 230V 72 500 3912 CORD CORD ARMOR D8 8 FOR SUI ALTERNATIVE PARTS 3 307 786 STANDARD ACCESSORIES NO CODE NO DESCRIPTION CASE DH20PB 303 659 SIDE HANDLE 303 709 DEPTH GAUGE
16. DAPTER A W3 8 MANUAL 971 797 ANCHOR SETTING ADAPTER A W1 2 MANUAL E 971 798 ANCHOR SETTING ADAPTER A W5 8 MANUAL ALTERNATIVE PARTS OPTIONAL ACCESSORIES DH20PB sean ESTs 971 799 971 800 971 801 971 802 971 803 982 684 ANCHOR SETTING ADAPTER W1 4 MANUAL ANCHOR SETTING ADAPTER W5 16 MANUAL ANCHOR SETTING ADAPTER B W3 8 MANUAL ANCHOR SETTING ADAPTER B W1 2 MANUAL ANCHOR SETTING ADAPTER W5 8 MANUAL 982 685 982 672 982 673 982 674 982 686 CENTER PIN A 109L FOR CORE BIT D32 38 CENTER PIN B 104L FOR CORE BIT D45 90 CORE BIT A 25MM CORE BIT A 29MM CORE BIT A 32MM INCLUD 642 GUIDE PLATE FOR CORE BIT 32MM 982 675 CORE BIT A 35MM INCLUD 644 982 687 GUIDE PLATE FOR CORE BIT 35MM 982 676 CORE BIT A 38MM INCLUD 646 982 688 982 677 GUIDE PLATE FOR CORE BIT 38MM CORE BIT B 45MM INCLUD 648 982 689 GUIDE PLATE FOR CORE BIT 45MM 982 678 CORE BIT B 50MM INCLUD 650 982 690 GUIDE PLATE FOR CORE BIT 50MM 303 625 303 626 CORE BIT SHANK SDS PLUS 25 38MM 105L CORE BIT SHANK SDS PLUS 25 38MM 300L 303 627 CORE BIT SHANK SDS PLUS 45 90MM 300L 303 046 BULL POINT SDS 250MM ROUND SHANK TYPE 303 044 CHEMICAL ANCHOR ADAPTER SDS 12 7MMX90L 303 045 303 820 CHEMICAL ANCHOR ADAPTER SDS 19 0MMX100L 950 275
17. HOLDER 306 342 HOLDER SPRING 984 118 WASHER 6 939 547 RETAINING RING FOR 020 SHAFT 10 PCS 7 314 876 GEAR COVER 8 301 654 TAPPING SCREW W FLANGE D5X35 9 314 881 O RING 10 981 328 SPRING H 959 155 STEEL BALL D3 97 10 PCS 314 878 O RING 314 877 CHANGE LEVER 307 688 OIL SEAL 307 690 SLEEVE 16 690 4DD BALL BEARING 6904DDPS2L 17 986 147 RETAINING RING FOR 037 HOLE 18 959 156 STEEL BALL D7 0 10 PCS 19 959 154 STEEL BALL 05 556 10 PCS 20 314 882 CYLINDER 301 677 SECOND GEAR 301 678 SPRING 301 679 WASHER 948 310 RETAINING RING FOR D30 SHAFT 301 671 SECOND HAMMER 26 301 672 O RING B 27 301 680 O RING 1 0 10 5 28 315 148 STRIKER 29 301 670 O RING A 30 301 668 301 666 PISTON PISTON PIN 303 977 WASHER C 314 880 INNER COVER 301 664 SPRING B 315 161 GEAR SHAFT SET 36 301 659 WASHER B 37 301 660 CLUTCH SPRING 38 301 661 CLUTCH 39 992 912 O RING S 8 40 306 990 RECIPROCATING BEARING 41 301 663 SPACER 42 626 VVM BALL BEARING 626VVC2PS2L 43 876 796 O RING P 22 44 608 DDM BALL BEARING 608DDC2PS2L 45 982 631 WASHER A 46 360 446U ARMATURE ASS Y 110V 115V INCLUD 44 45 52 46 360 446 ARMATURE 220V 230V 47 314 879 GUIDE ASS Y INCLUD 48 48 994 343 RUBBER BUSHING 49 340 398C ST
18. ameter 32 35 38 mm 1 1 4 1 3 8 1 1 2 Code No 982684 Center pin bit outer diameter 45 50 mm 1 25 32 2 Code No 982685 2 Guide plate Core bit outer diameter mm Core bit outer diameter 32 1 1 4 982686 50 2 982690 3 Core bit with guide plate The guide plate is not equipped with core bit with outer diameter of 25 mm 31 32 and 29 mm 1 5 32 25 31 32 45 1 25 32 m suam se 1 12 wmm 4 Core bit shank SDS plus shank n Jk ik Core bit shank Core bit outer diameter 25 38 mm Overall length 105 mm 4 1 8 Code No 303625 31 32 1 1 2 length 300 mm 11 52 64 Core bit shank B 076 Pit dua Overall length 300 mm 11 52 64 D Crushing operation rotation striking Bull point round type only SDS plus shank Code No 303046 E Bolt placing operation with chemical anchor rotation striking C Standard sockets available the market 12 7 mm 1 2 Chemical anchor adapter SDS plus shank 19 mm 3 4 Chemical anchor adapter SDS plus shank 12 7 mm 1 2 Chemical anchor adapter 303044 19mm 3 4 Chemical anchor adapter 303045 F Drilling hole and driving screw rotation only e Drill chuck chuck adapter G special screw and chuck wrench amp j SSI PRAIRIES 13 mm 1 2 Drill chuck Chuck adapter G 13VLR type SDS plus shan
19. at the claw protruding portion of the Reciprocating Bearing 40 and the claw protruding portion of the Clutch 38 are in contact After inserting Spring H 10 and Steel Ball D3 97 11 into the recessed portion of the Gear Cover 7 apply grease to the pin portion of the Change Lever 13 into the Gear Cover 7 so that it is positioned midway between the Hammer mark and the Drill mark Be careful that should the mounting position of the change lever be incorrect it will deform the claws of the change lever 3 Reassembly of the Oil Seal 14 Prior to reassembly apply grease to the inner circumference of the Oil Seal 14 However do not apply grease to its outer circumference Also when press fitting the Oil Seal 14 ensure it is straight and level 9 3 Lubrication Apply special grease N P C FG 6A Code No 980927 is recommended to the inner and outer circumferences of the Piston Pin 31 and Piston 30 O Ring A 29 mounted on the Striker 28 O Ring B 26 mounted on the Second Hammer 25 the Reciprocating Bearing 40 the Reciprocating Bearing 40 mounting portion of the Gear Shaft Set 35 the O Ring 1 0 10 5 27 and the clutch claw portions of the Cylinder 20 the inner circumferences of the metal inside the Inncer Cover 33 and external grooves of the Clutch 38 Also without fail insert 70 0 15 Ibs of special grease inside the Gear Cover 7 9 4 Tightening Torque Tappin
20. e and be released through the air escape slot and large cylinder respiratory hole provided on the inner wall of the cylinder Accordingly there is no change in the air pressure within the air chamber and movement of the striker idle striking operation is prevented The gripping force of the o ring on the striker is so small in comparison with the conventional mouth system that practically no pressing force at all is required to restart the striking operation Striker Coil spring Second gear Air escape slot Claw Piston O ring Reciprocating bearing Front ca Game Gear cover Travel distance Cylinder t n H Second hammer C IU V pem N oo First gear E Clutch Large cylinder respiratory hole Small piston respiratory hole Clutch spring Change lever Second shaft Slip mechanism The slip mechanism in the Model DH 20PB consists of a coil spring which applies a pre set amount of pressure to ensure the interlocking of three claws provided on the flange of the cylinder the final rotating shaft and three matching claws provided on the face of the second gear by which rotation is transmitted to the cylinder The second gear is fitted to the cylinder with a certain amount of play If an excessively large torque is applied to the tool shaft cylinder the force of the torque will exceed the pressure of the coil spring and cause the claws on the second gear to disengage from and ride over the claws on the cylinder so that the
21. easure the insulation resistance and conduct the dielectric strength test Insulation resistance 7MQ or more with DC 500 V Megohm Tester Dielectric strength AC 4 000 V 1 minute with no abnormalities 220 V 240 V and 110 V for U K products AC 2 500 V 1 minute with no abnormalities 110 V 127 V except U K products 9 8 No load Current Values After no operation for 30 minutes the no load m should be as follows mena 30 19 10 STANDARD REPAIR TIME UNIT SCHEDULES ps DH 20PB Housing Switch Armature Ass y Stator Cord Inner Cover O Ring Ball Bearing 608DD Washer A x2 Ball Bearing 608VV General Assembly Change Lever Front Cap Retaining Ring O Ring Grip Cylinder Ball Holder Steel Ball x 4 Holder Spring Second Gear Oil Seal Spring A Steel Ball Washer A Retaining Ring Second Hammer O Ring B O Ring Striker Spring B O Ring A Gear Shaft Set Piston Spacer Piston Pin Ball Bearing Washer C 626VV 04 Gear Cover Ball Bearing 6904DD Retaining Ring LIST NO E462 HITACHI o lt au O O O O LLI l Q t I m 2002 2 5 E1 20PB Model DH PARTS FEW cooo ommo DH20PB 306 345 FRONT CAP 306 992 GRIP 306 343 BALL
22. eed the designed amount of grease Excessive grease will reduce striking efficiency 8 2 Tool Structure While the structure is essentially the same as the Model DH 24PB the descriptions below are included to enhance your understanding of the tool and its mechanisms e Transmission of rotation Unlike conventional hammer drills the armature shaft in the Model DH 20PB is in parallel with the tool shaft the same structure that is employed in most impact drills This structure was adopted in order to make the Model DH 20PB more compact for easier handling and operability Thus the appearance of the Model DH 20PB is similar to that of an impact drill The rotation of the armature is transmitted to the second shaft via the first gear and causes it to rotate The second pinion provided on the second shaft engages the second gear mounted on the outer circumference of the cylinder The cylinder is coupled to the second gear by means of a slip mechanism and they rotate together The end of the cylinder also functions as the drill bit retainer The cylinder is key connected to the inserted drill bit by means of two key rails and transmits rotation to the drill bit steel ball is used to prevent the bit from falling 10 e Piston reciprocating mechanism In conventional hammer drills a piston is caused to reciprocate by a connecting rod and crank shaft and the crank shaft and the cylinder axis are at a right angle to each other Accordingl
23. es overhead dust collector B can be mounted on the Model DH 24PE to prevent dust and chips from falling downward Dust collector B is intended solely for use when drilling holes in concrete and cannot be used for drilling holes in steel or wood It is designed for use with drill bits with overall length of 166 mm 160 mm or 110 mm and cannot be used with any longer bits When using a drill bit with an overall length of 166 mm with dust collector B drilling up to a depth of approximately 72 mm is possible When using dust collector B ensure it is securely fastened to the grip on the main body with socket adapter B Although the socket and socket adapter B rotate together with the tool shank there is a steel ball between the outer race and the socket which serves as a ball bearing Should the dust cover be forced against the concrete surface it will not rotate even though the tool shank continues to rotate Should the tool be operated when the dust cover is not being held against a concrete surface inertia may cause dust collector B to become disconnected from the grip Accordingly caution the customer to press dust collector B and drill bit firmly against the concrete surface before turning on the switch to start drilling When dust collector B is used almost no dust and chips are scattered about However since the chips and dust remaining in the collector may scatter after completion of the drilling operation the customer should be
24. ficient use of the Model DH 20PB Hammer Drill by all of our customers it is very important that at the time of sales the salesperson carefully ensures that the buyer seriously recognizes the importance of the contents of the Handling Instructions and fully understands the meaning of the precautions listed on the Caution Plate attached to each tool 7 1 Handling Instructions Although every effort is made in each step of design manufacture and inspection to provide protection against safety hazards the dangers inherent in the use of any electric power tool cannot be completely eliminated Accordingly general precautions and suggestions for the use of electric power tools and specific precautions and Suggestions for the use of the Hammer Drill are listed in the Handling Instructions to enhance the safe efficient use of the tool by the customer Salespersons must be thoroughly familiar with the contents of the Handling Instructions to be able to offer appropriate guidance to the customer during sales promotion 8 REFERENCE MATERIAL 8 1 Lubrication It is not necessary to replenish the grease lubricant unless the tool is disassembled or there is grease leakage due to a defective seal Special grease is used in the striking section Should the striking section within the gear cover be disassembled carefully remove the old grease from all parts and on reassembly insert 70 g 0 15 lbs of new grease into the gear cover Be careful not to exc
25. g mechanism Thanks to the newly provided powerful motor the Model DH 20PB has 20 mm drilling capacity in concrete and the drilling speed is far faster than the competitors The Model DH 20PB 15 an excellent cost performance hammer drill expected to expand our market share 3 APPLICATIONS 1 Rotation and striking function e Drilling anchor holes e Drilling holes in concrete tile brick and similar materials 2 Rotation only function e Drilling holes in steel and wood with chuck adapter e Tightening and loosening machine screws and wood screws with chuck adapter Typical applications Air GCONGITIONING esse pen es Installation of air conditioners water coolers and heaters and air ducts e Piping and plumbing n6 Installation of gas water and sanitary facilities Electrical strane qus Installation of light fixtures and various electric appliances e Interior decoration Installation of seating display stands and partitions e Other civil engineering construction and repair work 4 SELLING POINTS Maker Model Overall length HITACHI DH 20PB 318mm 12 17 32 B 334 mm 13 5 32 Fast drilling speed 40 faster than B Convenient handle shape 10 slower than the Model DH 24PB when the pressing force is 10 kof Variable speed control switch and reversing switch 4 1 Selling Point Descriptions 1 Compact Maker Model Overall length
26. g Screws W Flange D4 57 69 Tapping Screws W Flange D5x35 8 9 5 Wiring Diagram Speed control switch p Mn Stator ra White oor 000 Ke Noise suppressor Black Cord Black 7 24 O O 206 Red Stator Fig 12 20 2 0 0 5 N m 20 5 kgf cm 17 4 4 3 in lbs 2 9 0 5 N m 30 5 kgf cm 26 0 4 3 in Ibs Reversing switch 4 2 c Blue e Armature e 3 Brown 1 9 6 Internal Wire Arrangement and Wiring Work Put the lead wires from the Stator 49 _under the Brush Holder 63 Brush Terminal 7 Choke Coil A O Carbon Brush 62 4 Brown from the 2 H Afi Carbon Brush 62 Gray from the Stator 49 Black from the Stator 49 Red from the Stator 49 Blue from the Carbon Brush 62 White from the Stator 49 END Ses Choke coil Armature 46 Transparent neutral wire of Noise Suppressor 60 Speed ene gat and oo Reversing Switch 59 17 4 TS Noise Suppressor 60 4 WW Cord 72 Fig 13 Schematic diagram soj c Additional Wiring Work General internal wiring can be accomplished by referring to paragraphs 9 4 and 9 5 The following Stator Carbon brush are special instructions for switch connection 1 Wiring of reversing switch Insert the lead wire black coming from the Stator into the terminal 1 of the reversing
27. k Note the tool is to be used for loosening screws open the three jaws of the drill chuck and securely fix the drill chuck to the chuck adapter G with the special screw a left hand threaded M6 screw when mounting the drill chuck onto the chuck adapter G a Chuck adapter G for SDS plus shank system 309828 13 mm 1 2 drill chuck 13VLR with chuck wrench Special screw M6 left hand threaded 981122 Chuck wrench 1 Cross recessed head Phillips bit 2 Slotted head minus bit Overall length 70 mm Overall length 50 mm For use with cross recessed head Phillips screw For use with slotted head minus screw J GA Tip thickness Stamped bit No Code No Applicable screw dia mm Bit ti Code No Applicable screw dia mm os esse _ G Driving screws rotation only For drilling holes in steel and wood Drill chuck Chuck adapter D 13VLA SDS plus shank Chuck wrench NOTE The 13VLA drill chuck and chuck adapter D cannot be used for reverse rotation If reverse rotation is to be used for loosening screws use the plus bit Bit No 2 described below by attaching it directly to chuck adapter D Chuck adapter D for SDS plus shank type 13 mm 1 2 drill chuck 13VLA with chuck wrench H Drilling screws rotation only e Plus driver bit overall length 25 mm for cross recessed head screws Bit No Chuck adapter
28. mbled e Loosen the four Tapping Screws W Flange D5 x 35 8 and remove the Gear Cover 7 The Inner Cover 33 and the Housing 53 are loosely fitted together Attempting to pull them out first could cause the Armature 46 to be pulled out at the same time causing damage to the Carbon Brushes 62 e Remove Spring B 34 from the end of the Gear Shaft Set 35 and turn the Gear Shaft Set 35 so that the Piston 30 moves to its maximum upper position inner cover side The arm of the Reciprocating Bearing 40 can then be disconnected from the Piston Pin 31 and the Gear Shaft Set 35 and the components mounted on it can be removed from the Inner Cover 33 as a unit e With a bearing puller Special Repair Tool J 30 Bearing Puller Ass y Code No 970804 is recommended remove the Spacer 41 from the Gear Shaft Set 35 Then take off the Reciprocating Bearing 40 At this time carefully note that the Spacer 41 must be aligned with and press fitted onto the 9 mm diameter end of the Gear Shaft Set 35 Move the Clutch 38 to the pinion side of the Gear Shaft Set 35 and pull off the O Ring S 8 39 The Clutch Spring 37 and Washer B 36 can then be removed from the Gear Shaft Set 35 2 Disassembly of the chuck section Front Cap 1 As shown in Fig 8 slide the Grip 2 in the direction indicated by the arrow mark and remove the Front Cap 1 The Grip 2 the Ball Holder 3 inside the grip
29. s the changing air pressure inside the air chamber between the piston and the striker causes the striker to move the continuously strike against the end of the second hammer At the same time the changing air pressure within the air chamber which moves the striker also provides an air cushion which absorbs the impact of the striking action As air leakage from the air chamber would weaken the air cushion effect and reduce impact absorption the o ring mounted on the striker is extremely important to seal the air Although special rubber material is utilized in construction of the o ring to make its effective service life as long as possible wear cannot be fully avoided Accordingly it is recommended that the o ring be replaced approximately once a year depending on the frequency of usage of the tool e Idle striking prevention mechanism The idle striking prevention mechanism in the Model DH 20PB is different from that of conventional hammer drills When the drill bit is lifted from the concrete surface on completion of drilling the second hammer moves to the position indicated by the continuous lines in Fig 3 and the protruding lip portion at the tip of the striker iS gripped by the o ring mounted on the inner wall of the cylinder In this state should the piston continue to move so that the small piston respiratory hole is blocked by the inner wall of the cylinder the air in the air chamber will pass through the large piston respiratory hol
30. switch and the lead wire white into the terminal 2 as shown in Fig 14 Insert the lead wire brown coming from the carbon brush into the terminal 3 and the lead wire blue into the terminal 4 After the insertion pull each lead amp 5 C e Stator Carbon brush Fig 14 Wiring of reversing switch wire slightly to check the lead wires do not come off To disconnect the lead wires insert a small flat blade screwdriver into the windows near the Noise suppressor Noise suppressor 2 Wiring of speed control switch Stator Stator terminals and pull out the lead wires Insert each cord into the terminal 1 and terminal M x D Ev D amp m CC m g 21 of the speed control switch as shown in Fig 15 and tighten the screw tightening torque 0 6 0 2 Nm 6 2 5 2 1 7 in lbs Insert the lead wire gray coming from the stator into the terminal M1 and the lead wire red into the terminal M2 Insert each lead wire black coming from the noise suppressor into the terminals C1 and C2 After the insertion pull each lead wire slightly to check that S the lead wires do not come off To disconnect the 9 E lead wires insert a small flat blade screwdriver into S mn Cord Cord the windows near the terminals and pull out the lead Fig 15 Wiring of speed control switch DH 20PB wires 9 7 Insulation Tests On completion of reassembly after repair m
31. the spline on the second shaft spline Claws on the surface of the clutch engage matching claws on the reciprocating bearing to convert the rotation into reciprocating motion The clutch can travel back and forth on the second shaft Claws on the surface of the clutch is pressed against on the reciprocating bearing by the force of the clutch spring during usual operation Rotation Striking The reciprocating bearing is fitted on the second shaft with some play When the change lever is set to the Rotation Only drill mark position the eccentric pin of the change lever forces the clutch to move against the pressure of the clutch spring in the direction of the front cap so that it disengages from the claws on the reciprocating bearing and the reciprocating bearing stops rotating on the second shaft When the change lever is returned to the Rotation Striking hammer mark position the force of the clutch spring presses the clutch back against the reciprocating bearing so that the claws engage to transmit rotation to the reciprocating bearing once more 13 8 4 Rotation Only no striking Turn the change lever fully clockwise to the drill mark position to obtain Rotation Only function To use the tool for drilling or driving screws the chuck adapter and a drill chuck optional accessories must be used In older models such as the Models DH 22 and DH 22V when the chuck adapter is mounted the second hammer moves
32. y the armature shaft and the cylinder axis are at a right angle to each other In the Model DH 20PB through adoption of a spiral drive system a mechanism using a reciprocating bearing a more compact design has been achieved by arranging the armature shaft in parallel with the cylinder axis Referring to Fig 2 the rotation of armature is transmitted to the second shaft via the first gear The second shaft rotation is further transmitted through a spline to the clutch which engages with a reciprocating bearing and causes it to rotate However as illustrated circular grooves on the inner race of the reciprocating bearing are positioned on an angle of inclination with relation to the second shaft The rotation of the inner race and the shaft causes that angle of inclination to change regularly forward and back with relation to the second shaft and produces a rocking motion to the outer race of the reciprocating bearing Finally a rod extending from the outer race of the reciprocating bearing is connected to the piston by a piston pin and causes the reciprocating motion of the piston Steel ball Cylinder Piston _ Piston pin _ Armature Tool shaft CE Key rail 2 pieces Armature shaft First gear Second shaft Circular groove Reciprocating bearing Clutch Fig 2 re e Striking function The piston reciprocates within the cylinder to move the striker in the same manner as in conventional hammer drills As the piston reciprocate
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