MF3620 - Sewing machine JUKI - Free user manual and instructions

USER MANUAL MF3620 JUKI

を防止するカバーです。vii For the sewing machine, automatic machine and ancillary devices (hereinafter collectively referred to as "machine"), it is inevitable to conduct sewing work near moving parts of the machine. This means that there is always a possibility of unintentionally coming in contact with the moving parts. Operators who actually operate the machine and maintenance personnel who are involved in maintenance and repair of the machine are strongly recommended to carefully read to fully understand the following SAFETY PRECAUTIONS before using/maintaining the machine. The content of the SAFETY PRECAUTIONS includes items which are not contained in the speci¿cations of your product. The risk indications are classi¿ed into the following three different categories to help understand the meaning of the labels. Be sure to fully understand the following description and strictly observe the instructions. Warning label

1. Never bring your fi ngers under the needle when the power switch is turned ON or

the machine is in operation.

2. Never bring your fi ngers, hair or clothes close to the pulley and needle or place any-

thing on the pulley and under the needle while the machine is in operation.

3. Never operate the machine with the safety devices such as belt cover, needle bar

thread take-up cover, fi nger guard, eye guard cover, etc. removed.

4. Be sure to turn OFF the power and perform the work after ascertaining that the sewing

machine does not run even when the starting pedal is depressed in case of checking, adjusting, cleaning, threading or replacing the needle of the sewing machine.

5. Never operate the sewing machine with the ground wire for the power supply re-

moved so as to ensure safety.

6. Be sure to turn OFF the power switch in advance in case of inserting/removing the

7. In time of thunder and lightning, stop your work and disconnect the power plug from

the receptacle so as to ensure safety.

8. When you move the sewing machine from a cold place directly to a warm place, dew

condensation may result. Turn ON the power to the machine after you have con- fi rmed that there is no fear of dew condensation.

9. In case of maintenance, inspection, or repair, be sure to turn OFF the power switch

and confi rm that the sewing machine and the motor have completely stopped before starting the work. (In case of the clutch motor, it continues rotating for a while by the inertia even after turning OFF the power switch. So, be careful.)

10. Be careful of handling this product so as not to pour water or oil, shock by dropping,

and the like since this product is a precision instrument.

1. To prevent accidents caused by electric shock, never open the motor control box

cover or touch the components inside the control box while the power switch is ON.

CAUTION BEFORE OPERATION

• Be sure to fi ll the oil hole with oil designated by JUKI before use.

• Clean the sewing machine thoroughly before using it for the fi rst time.

• Remove all dust collected on the sewing machine during the transportation.

• Confi rm that the voltage and phase are correct.

• Confi rm that the power plug is properly connected.

• Never use the sewing machine in the state where the voltage type is different from the designated one.

• The direction of rotation of the sewing machine is clockwise as observed from the pulley side. Be careful not to rotate it in reverse direction.

• When operating the sewing machine, turn ON the power switch after properly setting the head on the table.

• For the fi rst month after set-up, use the machine at a reduced sewing speed of 3,200 sti/min or less.

• Operate the pulley after the sewing machine has totally stopped.

To avoid malfunction and damage of the machine, confi rm the following.xii ENGLISH DECLARATION OF INCORPORATION OF PARTLY COMPLETED MACHINERY We hereby declare that the sewing machine (sewing head) described below ;

1. Must not be put into service until the machinery to which it is incorporated has been declared in

conformity with the provisions of the Directive 2006/42/EC, and

2. Conforms to the essential requirements of the Directive 2006/42/EC, described in the technical

3. To be prepared with the above technical documentation compiled in accordance with part B of

4. Also to conform to the RoHS Directive 2011/65/EU

5. Relevant information on which should be transmitted in response to a reasoned request by the

national authorities, by the electronic method or other according to the request. Applied harmonized standards, in particular :

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3. Installing the belt cover for the clutch

motor ...................................................... 28

4. Installing the presser lifting lever .......30

8. Installing the chain-off thread cutting

2. Adding oil to the silicon container ......40

3. Adjusting the presser foot pressure ...45

4. Adjusting the micro-lifter .....................46

5. Adjusting the differential feed ratio ....47

6. Adjusting the stitch length ..................48

7. Adjusting the thread tension ...............50

8. Adjusting the knife pressure ...............51

1. Adjusting the height of the needle ......53

2. Replacing the presser foot ..................56

3. Adjusting the covering thread carrier

and covering thread hook ....................66

4. Replacing/adjusting the knife ..............68

5. Adjusting the height of the feed dog ..72

6. Adjusting the looper .............................74

7. Adjusting the needle guard (front) ......76

8. Adjusting the needle guard (rear) .......78

9. Adjusting the needle thread guard .....79

10. Adjusting the needle thread path ........83

11. Adjusting the looper thread cam .........85

12. Adjusting the looper thread cam thread

Adjusting the top covering thread path

Adjusting the top covering thread cam

Adjusting the lap former (MF-3620L2**)

2. Replacing the lubricating oil ................97

3. Points to be applied with grease .........99

4. How to install the control box

Model name 4-needle, feed-off-the-arm coverstitch machine for fl at seam Model MF-3620 MF-3620*B Drive method Belt drive Direct drive Stitch type JIS F46(US-607) Example of application Seam side of knit and knitted fabric products, join crotch, etc. Max. sewing speed (Normal) 4,200sti/min (3,200sti/min) Needle gauge 5.2mm

6.0mm Feed pitch 1.6 to 2.5mm Applicable needle (standard count) FL×118GCS (#9 to 12)(standard count #10S) Applicable retainer needle (standard count) FLG-8 (standard count #8) Needle bar stroke 30 mm Dimensions 426 mm (height) x 290 mm (width) x 414 mm (length) 426mm (height) x 290 mm (width) x 560mm (length) Machine head weight 22.5kg 26.5kg Lift of presser foot 6.5mm (Micro-lifter mechanism is provided) Feed adjustment method Main feed - slide type stitch pitch adjustment method Differential feed - lever adjustment method Lubrication method Gear pump type automatic lubrication Lubricating oil JUKI New Defrix Oil No.2 Oil reservoir capacity Front oil reservoir capacity 70 to 80 ml Rear oil reservoir capacity 60 to 70 ml Noise - Equivalent continuous emission sound pressure level (L

) at the workstation: A-weighted value of 80 dB ; (Includes K

Presser spring regulator

Thread take-up lever guard

Oil circulation inspection windows (rear)

Needle thread silicon oil lubri- cating unit

Oil circulation inspection win- dows (front)

Screw of stitch adjustment window

Oil drain screw (front)

Avoidance adjustment hole

Thread take-up lever

Oil drain screw (rear)

Motor used Machine head fi xing base asm. Table Auxiliary table Direct-drive motor

Supplied with the machine head Servomotor MT-01 40035801 40036113

to be ordered separately

At the beginning, the procedure of pulling out the machine head after opening the package is explained.

under the center of the frame. Put there one of your hands and support the machine head. Next, hold handwheel

with the other hand.

2) Pull out the machine head while another worker is

pressing the packing material. Next, the procedure of installing the machine head is explained. Fix the machine head with head fi xing screw

by two persons or more as shown in Fig. 1. In addition, tightening torque of head fi xing screw

is 12 to 15 N•m. The work of installing/removing the machine head is accompanied with the danger of the fall of machine head. Be sure to use the exclusive lift or execute the work with two persons or more and do not take the hands off until the head fi xing screw is securely tightened. In addition, when tightening the fi xing screw, laterally adjust the head position so that V-belt is set straight. If the V-belt is set bent, the progress of abra-sion of V-belt is increased.– 17 – La procédure de retrait de la tête de la machine de l'emballage après l'ouverture de celui-ci est tout d'abord expliquée.

1) Attach belt cover C

to the arm support (on the motor side) by means of two setscrews

When removing or tilting the machine head, be sure to remove belt cover C

at the location shown in the illustration by means of the two setscrews

4) Adjust the angle of idler (asm.)

so that the belt sags 4 mm when the approximate center of the span of belt

pressed with a 3 N (300 g) load. After completion of the adjustment, fi x the idler (asm.) by securely tightening two setscrews

Rotate the belt by two or three revolutions every time you have changed the angle of idler (asm.)

to break in the belt. Then, measure the amount of the belt sagging.

Be sure to fi rmly tighten two setscrews

. If they loosen, the belt can slip off from the sprocket (asm.) Reference value of the tightening torque : 30 ± 5 kgfcm (3.0 ± 5 N

If the belt comes in contact with the cover while the sewing machine is in operation, stretch the belt.

5) Insert belt cover (asm.)

into the clearance in the direct-drive motor base and fi x it at the location shown in the illustration by means of three setscrews

30 ± 5kgfcm (3,0 ± 5N

Turn the power ON with switch

, and fi x it with a fi xing screw

at the top side of the belt cover (asm.)

SC-910– 24 – (1) For the machine using a servomotor (MT-01, SC-510/M51), the belts should be combined as shown in the table below. Mount base Control box/Motor Motor pulley

Belt on the motor side

Belt on the machine head side

Included in the MT accessories for the SC-510 (part number: 40039132).

• The commercially-available motor pulley near to the counted value is designated since the outside diameter of the commercially-available motor pulley counts by 5 mm. Use a motor pulley which is adapt- able to this sewing machine. The sewing speed exceeds the max. sewing speed of this sewing machine and machine trouble will be caused unless a motor pulley which is adapt- able to this sewing machine is used. When you use a new sewing machine, use the machine at a speed of 3,200sti/min or less for the fi rst 200 hours (approximately one month). A good result can be obtained in terms of the durability. (2) See the following table for the machine using a clutch motor of 3-phase 2-pole 400-watt (1/2 HP).

Installing the belt cover for the clutch motor

with three setscrews.

through the sewing machine pulley. Put V-belt

4) Install the belt cover on the machine table with

(at four locations). Attach stop cock

of the clutch motor.

using three setscrews

• For the MT-01 servomotor type, refer to the Instruction Manual for the MT-01.

of presser lifting lever

In this state, fi x it on thread tension base

Next, pass connecting link

as shown in the fi gure and insert O-ring

into the both ends of it. Finally, fi x it with setscrew

Apply the grease (Part No.: 40013640) sup- plied with the unit to the sliding parts en- circled with (four locations) at least once every year.

, supplied with the unit. Fix thread guide

Direction of rotation of the sewing machine is the same as that of the hand of watch as viewed from the handwheel side. It is counterclockwise as viewed from the working position of the operator. Never rotate it in the reverse direction. Lubricating pump fails to work and seizure will be caused.

to provide the dimensions given in the illustration below (two points). Adjust the rightward/leftward tilt of thread guide pipe

that the center of the hole in the pipe meets the center of the thread path hole in thread tension thread guide plate

on the machine table with nuts

1. Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the

2. Do not touch your fi ngers or hands to the blade section of knife. so as to prevent fatal accidents.

Perform the adjustment work by the maintenance engineers who are familiar with the sewing machine and trained for the safety so as to prevent accidents caused by unfamiliarity or wrong adjustment. WARNUNG :

on chain-off thread cutting knife

, install them together on the sewing machine with two setscrews

1) Remove oil circulation inspection windows

3) For the oil to be added through oil hole (front)

, pour it until the indicator bar reaches short of the upper red engraved marker line while visually observing oil gauge

For the oil to be added through oil hole

, pour it until the oil surface comes short of the upper engraved marker line while visually observing oil gauge

from the side. If the oil is added until the oil surface is above the upper engraved marker line, the oil quantity is excessive resulting in oil leakage. Be sure to stop adding oil before the oil surface reaches the upper engraved marker line.

6) After completion of oiling, attach oil circulation inspection window

7) Check to be sure that the nozzles inside oil circulation

feed lubricating oil when the sewing machine is operated. If no oil is fed from the nozzles, remove pump screws

(2 pcs.) and put few drops of lubricating oil into the tapped holes. Once squirt of oil from the nozzles is confi rmed, attach pump screws

(2 pcs.) back in place.

When the machine is used for high-speed sewing or with synthetic thread and synthetic cloth, open cover

and add silicon oil (dimethyl silicone) into the container to prevent thread breakage or stitch skipping. When silicon oil adhered to the components other than the silicon container, be sure to wipe it out. If the components to which silicon oil adhered are kept being used without wip- ing out the oil, sewing machine trouble will be caused. 高速缝制和使用化纤线、化纤布料时，为了防止断线、 跳针，请打开机线冷却槽

2) The needle has a fl at part (

) in the shank as shown in the illustration. Insert the needle into the hole in needle clamp

until it will go no further in such a way that the fl at part of the shank faces toward the operator.

of the needle while making sure that the screw comes in contact with the fl at part.

, thread take-up lever guard

, looper thread guide cover

, and properly thread the machine head.

is top covering thread and

is looper thread. After completion of threading, be sure to close the covers back in place. Den Deckel

1) Bring the needle bar to its lowest position so that the

feed dog reaches the position lower than the top sur- face of the throat plate.

and turn the adjusting screw counter- clockwise to lift the presser foot.

3) Once the presser foot is located at the desired posi-

to the right. In this case, the finished material is gathered. The ratio is decreased by moving the lever to the left. In this case, the fi nished mate- rial is stretched. Setscrew

is used for fi xing lever

and keeping the dif- ferential feed amount constant.

1) Remove plug screw

and adjust the stitch length by moving the screw upward or downward. At this time, be sure to only loosen setscrew

instead of removing it.

and attach plug screw

4) Check to be sure that the rear needle guard does not

come in excessive contact with the needle. Be sure to adjust the stitch length after having completed the adjustment of the differential feed.

Top covering thread tension nut

Bring the needle bar to its lowest position and loosen set- screw

. Adjust the knife pressure by moving knife mount- ing base guide collar

upward or downward. Move the collar upward to increase the knife pressure, or downward to decrease it. Standard height

of knife mounting base guide collar

is 1.0 mm. When tightening setscrew

, be sure to check that knife

1) When the needle bar is in its upper dead point, loosen

upward or down- ward to adjust distance

to the top end of right needle

to 13.5 mm when the needle gauge is 5.2 mm, or to 12.7 mm when it is 6.0 mm.

2) After the adjustment, adjust the relation between the

needle hole in the throat plate and the needle so that clearances

How to remove the presser foot

1) Remove the needle.

(4 pcs.) to re- move face plate

in the presser bar position bracket.

in the knife mounting base guide collar to let the assembly including the upper knife, knife mount- ing base and shaft move freely.

(2 pcs.) to re- move knife mounting base guide

from knife driving base

together with the upper knife and other related parts.

in the presser foot to remove presser spring regulator

Then, lift the presser bar to such an extent that it is disengaged from the presser foot.

of the presser foot from the lever section of carrier hook sleeve

8) Remove the presser foot diagonally

backward while turning it in the direc- tion of the arrow.

How to install the presser foot

Attach the presser foot between the presser guides (right) and (left) from diagonally backward while turning it counterclockwise.

into the lever section of carrier hook sleeve

Put the presser bar in carrier hook segment

and temporarily fi x with setscrew

Check to be sure that the presser foot moves up and down smoothly with no lateral backlash. If it does not, loosen setscrew

in presser foot guide (left)

to adjust the presser foot properly.

Attach knife mounting base guide

on knife driving base

together with the upper knife and other related parts with setscrews

Bring the needle bar to its lowest position. Adjust the position of knifse mounting base guide collar

and that of the upper knife. (Refer to

for the adjusting procedure.)

Attach presser spring regulator

in the presser foot once to check to be sure that the stepped part of the presser bar comes in contact with the main body of the presser foot. Then, tighten setscrew

in the presser foot.

with clearance A of 1 mm provided between presser bar position bracket

When the micro-lifter function is used, adjust it after completion of the aforementioned steps of procedure.

To protect against possible personal injury due to abrupt start of the machine, be sure to start the follow- ing work after turning the power off and ascertaining that the motor is at rest.– 58 –

Covering thread carrier Loosen setscrew

. Adjust so that the covering thread loop made by the thread eyelet section goes behind the left needle and left medium needle when covering thread carrier

approaches closest to the needle.

Covering thread hook Loosen setscrew

. Adjust so that a clearance of 0.5 mm is provided between covering thread hook

when covering thread hook reaches its rightmost position. Turn the sewing machine by one revolution to check to be sure that covering thread hook

does not come in con- tact with covering thread carrier

When adjusting covering thread carrier

and covering thread hook

Replacing/adjusting the upper knife

. Lift knife mounting base

upward to draw out upper knife

. Then, re- place it with a new one.

so that its depth of mesh with lower knife

is 0.3 to 0.7 mm when the upper knife reaches its leftmost position. Then, tighten knife fi xing screw

Replacing/adjusting the lower knife

1) Loosen lower knife fi xing screw

. Lift knife mounting base

up- ward to draw out lower knife

. Then, replace it with a new one.

2) Adjust the position of lower knife

of 0.8 to 1.6 mm is provided between its blade point

and the main body of the presser foot. Then, tighten lower knife fi xing screw

Adjusting the angle of mesh of the knife Loosen upper knife fixing screw

. Adjust the knife angle by turning knife angle adjusting screw

with the hexagonal wrench supplied with the unit. Then, tighten upper knife fi xing screw

1) Bring the feed dog to its highest position and loosen

2) Adjust so that crest

1.2 to 1.5 mm higher than the top surface of the throat

plate. Then, tighten setscrew

in differential feed dog

. Adjust the position of differential feed dog

so that it is fl ush with main feed dog

. Then, tighten setscrew

reaches its leftmost position, the standard distance between the top end of looper

and the center of the left needle is 4.0 to 4.4 mm for the needle gauge of 5.2 mm, or is 4.6 to 5.0 mm for the needle gauge of 6.0 mm. Loosen setscrew

in the looper base and carry out adjustment.

Longitudinal position of the looper Adjust so that a clearance of 0 to 0.05 mm is provided be- tween the top end of looper

when the looper moves from the left to the right to reach the position at which the top end of looper

aligns with the center of the left needle.

. Turn adjusting screw

clockwise to move looper base

toward the operator side, or counterclockwise to move it away from the operator side.

(2 pcs.) in needle guard (front)

Adjust so that a clearance of 0 mm is provided between looper

and the left needle when looper

moves from the left to the right to reach the position at which the top end of looper

aligns with the center of the left needle. After the adjustment, check to be sure that, when looper

is moved from the left to the right, the back face of the needle comes in contact with the top end of the looper and the needle does not deviate to the right. Die Befestigungsschrauben

between needle guard (rear)

and the needle is 0.05 to 0.1 mm when needle guard (rear)

approaches closest to left needle

and adjust the needle guard (rear). After the adjustment, check to be sure that, when looper is moved from the left to the right, the needle does not devi- ate to the right.

1) Bring thread take-up lever

to its lowest position.

. Adjust the height of the top end of needle thread guard

to the height of needle thread

of the right needle. Fix the needle thread guard with screw

3) Raise the top end of needle thread guard

above the top end of needle thread guard

by 1 mm and fi x with screw

4) Raise the top end of needle thread guard

above the top end of needle thread guard

by 2 mm and fi x with screw

5) Raise the top end of needle thread guard

above the top end of needle thread guard

by 3 mm and fi x with screw

Check to be sure that the top ends of the respective needle thread guards are in a horizontal position. Loosen screw

and adjust the size of the needle thread loop by moving the needle thread guard upward or downward. Move the needle thread guard upward to increase the size of the needle thread loop, or downward to decrease it.

/ Adjusting the needle thread path /

. Align the height of the hole in needle thread path

in needle thread path base

. Fix the needle thread path with screw

. Adjust the height of needle thread path

so that it is lower than needle thread path

. Adjust the height of needle thread path

so that it is lower than needle thread path

. Adjust the height of needle thread path

so that it is lower than needle thread path

by 15 mm. Move the needle thread path downward to tense the needle thread, or upward to loosen it. Finely adjust the thread ten- sion according to the material or thread to be used.

and looper thread guide cover

2) The standard timing that the looper thread passes

of looper thread cam

is when the needle bar comes down from its highest position by 2.8 mm. Loosen setscrews

(2 pcs.) to adjust the looper thread cam. If the timing for looper thread cam

is advanced, the looper thread take-up amount will be increased. If the timing is retarded, it will be decreased.

3) After completion of the adjustment, close top cover B

and looper thread guide cover

When fi xing looper thread cam

, carefully prevent it from coming in contact with cam thread guide mounting base (asm.)

. If the former comes in contact with the latter, stitch- ing failures or noise can be caused.– 87 –

can be adjusted. The standard adjustment is obtained by positioning looper thread cam thread guide

at its rightmost position. Moving looper thread cam thread guide

to the left increases the looper thread take-up amount. When fi xing looper thread cam thread guide

, carefully prevent it from coming in contact with looper thread cam. If the former comes in contact with the latter, stitching failures or noise can be caused.

. Then, the thread eyelet height in cov- ering thread guide

can be adjusted. The standard adjustment of the distance between the top surface of looper thread guide plate

and the top surface of the top end of covering thread guide

is 5.2 mm. Move covering thread guide

downward to increase the covering thread take-up amount, or upward to decrease it. When fi xing covering thread guide

, carefully prevent it from coming in contact with covering thread cam

If the former comes in contact with the latter, stitching failures or noise can be caused.

(2 pcs.) to adjust the timing for cov- ering thread cam

The standard timing for the covering thread cam is ob- tained by adjusting the cam so that the covering thread

rests within 0 to 1 mm from the crest of the cam when cov- ering thread hook

catches the covering thread. When fi xing covering thread cam

, carefully prevent it from coming in contact with cover- ing thread guide

If the former comes in contact with the latter, stitching failures or noise can be caused.

to adjust the lateral position of lap for- mer

Adjust the lateral position of the lap former according to how the right and left materials overlap or the state of the feed. Die Befestigungsschraube

. Clean up the grooves in the throat plate, grooves in the feed dog teeth and the peripheries of looper

In case of the new sewing machine, replace the lubricating oil (JUKI New Defrix oil No.2) with new one after using it for approximately one month. Then replace the lubricating oil every six months. Two oil drain openings are provided as shown in the illus- tration. When tilting the machine head in order to drain oil, remove the belt cover C referring to

and presser foot segment

periodically once a year. In addition, apply grease on the above-stated sliding sur- face also when the presser foot is replaced.

Decoration bolt (supplied with the machine haed)

Accessories for control box

Control-box mounting plate

Suspend the control box from underside of the table, as shown in the above illustration, at each of the three supporting points with washer

while placing bracket

supplied with the unit between the box and the table.

1. If you use the decoration bolt supplied with the SC-921, the control box cannot be installed since the

bolt interferes with the control box.

2. If the control-box mounting plates are fi xed on the table in a wrong installing direction or with the

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SEWING MACHINERY BUSINESS UNIT