DH4-B980 Service ManualCONTENTS1. MECHANICAL DESCRIPTIONS1-1.
Upper and lower shaft mechanisms1-2. Needle bar and thread take-up
mechanisms1) Needle bar mechanism2) Thread take-up mechanism
1-3. Zigzag mechanism1-4. Needle bar rocking mechanism1-5. Feed
mechanism1) X-direction feeding2) Y-direction feeding
1-6. Cloth presser and cloth stretching mechanisms1) Cloth
presser mechanism2) Cloth stretching mechanism
1-7. Cutter mechanism1-8. Looper mechanism1-9. Spreader
mechanism1-10. Double chain stitch looper mechanism
2. DISASSEMBLY2-1. Covers and cloth presser plates2-2. Feed
mechanism2-3. Lubrication2-4. Looper and spreader2-5. Needle bar
rotating mechanism2-6. Looper base2-7. Needle bar, thread take-up,
and zigzag mechanisms2-8. Knife pipe assembly2-9. Lower shaft
mechanism2-10. Synchronizer2-11. Upper shaft mechanism2-12. Cutter
mechanism2-13. Zigzag fork
3. ASSEMBLY3-1. Zigzag fork3-2. Cutter mechanism3-3. Upper shaft
mechanism3-4. Lower shaft mechanism3-5. Upper thread trimmer
mechanism3-6. Attaching the knife pipe and the knife base1) Knife
pipe2) Knife base
3-7. Driving gear shaft mechanism1) Assembling the needle bar
gear and the needle bar driving gear2) Adjusting the set collar of
the needle bar gear3) Adjusting the backlash between the needle bar
gear and the needle bar driving gear
3-8. Needle bar, thread take-up, and zigzag mechanisms1)
Eliminating end play of the thread take-up on the arm2) Applying
grease to the ends of the thread take-up spring3) Eliminating end
play of the needle bar driving lever4) Eliminating end play of the
driving rod5) The strength to tighten the set screw of ball bearing
25/206) Eliminating end play of the zigzag rock shaft7) Eliminating
end play of the zigzag lever8) Attaching the needle bar yoke and
the needle bar level feed link9) Attaching needle bar bush (U) and
the needle bar10) Eliminating end play of the needle bar block11)
Adjusting the needle bar in the radial direction12) Attaching the
needle bar block assembly13) Adjusting the height of the needle
bar
3-9. Looper base3-10. Needle bar rocking mechanism1) Driving
looper shaft2) Needle bar rocking mechanism
3-11. Looper and spreader3-12. Lubrication1) Machine head2)
Driving gear shaft
3-13. Feed mechanism1) X direction2) Y direction3) Attaching the
X-feed guide shaft
3-14. Synchronizer3-15. Covers and presser mechanism3-16. Safety
switch assembly
4. ADJUSTMENT4-1. Adjusting the cloth presser lift height4-2.
Adjusting the cloth presser plate4-3. Adjusting the cloth spreading
amount4-4. Adjusting the position of the cloth presser4-5.
Adjusting the X-home position4-6. Adjusting the Y-home position4-7.
Adjusting 0 position (reference line) of the needle4-8. Adjusting
the home position of the looper base4-9. Fine adjustment of knife
position4-10. Adjusting the sideways movement of the cutter
lever4-11. Adjusting the height of the throat plate4-12. Adjusting
the heights of the spreader and the looper4-13. Adjusting the loop
stroke4-14. Adjusting the height of the needle bar4-15. Adjusting
the clearance between the lopper and the needle4-16. Adjusting the
needle guard4-17. Adjusting the spreader mounting position4-18.
Adjusting the spreader timing4-19. Adjusting the amount to pull the
upper thread and tension release4-20. Adjusting upper thread
trimming4-21. Adjusting the lower thread trimmer4-22. Adjusting the
position of the lower thread presser (for specification -02)4-23.
Adjusting the rotating centers of the needle bar and the lopper
base4-24. Adjusting the needle bar stop position
5. POWER SUPPLY EQUIPMENT5-1. Fuses1) Fuse positions2) Fuse
capacity3) Replacing the fuses
5-2. PCBs1) PCB positions2) PCB functions
5-3. Replacing the PCBs1) Replacing the CPU PCB (PDH-A1-CPU)2)
Replacing the PMD PCB (PDH-A2-PMD)3) Replacing the PAL-A PCB
(PDH-A1A-PAL)4) Replacing the PAL-B PCB (PDH-A1B-PAL)
5-4. DIP switches1) Panel DIP switches2) PCB DIP switches
5-5. Sensors1) X home position sensor2) Y home position sensor3)
Looper base home positon sensor (Theta home position sensor)4)
Upper thread trimmer OFF sensor5) Knife ON sensor6) Lower thread
trimmer OFF sensor7) Safety sensor
5-6. Connectors in the control box1) Connector layout2)
Connector explanation
5-7. Harness connection in the control box1) Harness connection
between the control box and the printed circuit boards2) Connection
between printed circuit boards (PCBs)3) PCB connector pin layout4)
Wiring diagram (1/3)
5-8. Main motor, push button switch, and connecting wire1) Main
motor2) Push button switch3) Specifications for main motor, push
button switch and connecting wire4) Wiring diagram (1/2) (push
button switch, main motor (Z-axis motor), and connecting wire)
5-9. Connection between main motor and control box1) Connecting
wire2) Wiring diagram
5-10. Z-axis motor specification list5-11. Connection between
Z-axis motor and control box1) Wiring diagram2) Connection between
control box and Z-axis motor
6. AIR PRESSURE MECHANISM6-1. Solenoid valves and air tubes1)
Adjusting the solenoid valve speed controllers2) Air tubes
6-2. Air tube layout
7. SOFTWARE7-1. Motion flowchart7-2. Input check list7-3. Output
check list7-4. Error codes and countermeasures7-5. Setting special
specification
