JUKI LK-1941 Engineer'S Manual Download Page 12

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Standard Adjustment

3) Adjusting the main shaft sensor

Face A

Setscrew

Sensor cover

Slit plate passes
the center.

Slit plate

(2) Adjusting the intermediate presser components (LK-1942)

1) Adjusting the position of the intermediate presser cam

①

Align engraved dot A of the intermediate presser cam with engraved dot B of the main shaft in the

direction of rotation.

②

Clearance provided between section C of the intermediate presser driving arm and section D of the

machine arm boss is 0.5

0.2 mm in the state that the clearance becomes narrowest (lower dead point

of intermediate presser).

0.5

0.2 mm

Intermediate

presser cam

Intermediate presser

cam stopper

Intermediate

presser roller

Summary of Contents for LK-1941

Page 1: ...29343605 No E340 01 ENGINEER S MANUAL Computer controlled High Speed Shape tacking Industrial Sewing Machine with Full rotary Three fold Capacity Hook LK 1941 LK 1942 ...

Page 2: ......

Page 3: ...ction 2 Standard Adjustment which contains important information on the maintenance of LK 1941 LK 1942 The Standard Adjustment consists of two parts the former part presents illustration and simplified explanation for the convenience of reconfirmation of the required adjustment values in carrying out actual adjustment after reading this manual once and the latter part provides Results of Improper ...

Page 4: ...opper 17 10 Timing belt tension 19 5 Adjustment of the thread trimmer mechanism components 21 1 Adjusting the thread trimmer cam 21 2 Adjusting the thread trimmer link stopper screw 21 3 Position of the thread trimmer shaft 23 4 Position of the cam installing link stopper 23 5 Position of the thread trimmer magnet arm 25 6 Installing position of the moving anf counter knives For H and G types 27 7...

Page 5: ...ot wire output 70 CP 6 Hot wire output 71 7 EXTERNAL INPUT OUTPUT 72 8 PARTS GREASE OR LOCK TITE PAINT IS APPLIED 76 9 PRESSER DIMENSIONS 78 10 HOW TO USE OPTIONALS 79 1 Needle cooler 79 1 Installing the needle cooler compl 79 2 Installing the solenoid valve 81 3 How to use the needle cooler 83 2 Thread tension controller No 3 inverting clamp device 83 1 Installing the tension controller No 3 B501...

Page 6: ...o automatically stop machine 17 Max sewing speed limitation The max sewing speed can be set limited to any value within a range of 200 to 2 200 rpm using the up down key 100 rpm steps 18 Pattern selection 1 to 99 patterns can be selected by specifying the desired pattern Nos 19 Bobbin thread counter Tells the time to replace the bobbin by the bobbin thread counter Max 9 999 pcs 20 Production count...

Page 7: ... types only Air regulator Pedal switch 1st step Feeding frame switch 2nd step Start switch Needle thread breakage detecting plate Wiper switch Temporary stop switch Intermediate presser for LK 1942 only Feeding frame Machine head Thread stand Operation box Control box Power switch ...

Page 8: ...eed Counter Bobbin winder Threading Heat cutter temperature For Z type only Sewing LED Item selection LED Selection key Every time this key is pressed the selection will be made as follows Feed backward key Feed forward key Reset key Data indication Ready key Function key ...

Page 9: ... standard value Clears all the set values Clears all the set values Origin retrieval Travel to the sewing start Reset of count value Stop of bobbin thread winding Pattern No X scale Y scale Speed Counter Bobbin winder Threading Heat cutter temperature Change over of selection items Set No Set value Set No Set value Set No Set value CP 1 CP 2 CP 3 CP 4 CP 5 CP 6 Stop of bobbin thread winding Additi...

Page 10: ...tandard adjustment clearance provided between the counter weight and the main shaft front bushing is 0 5 mm 2 Installing the main motor Main shaft rear bearing Machine arm Rubber ring Flat section Screw No 1 Servo motor 0 5 Counter weight Thrust collar B Main shaft intermediate bushing Main shaft front bushing Thrust collar A Thread trimmer cam ...

Page 11: ...motor and the coupling 0 5 mm fit the screw No 1 to the flat section Then install the coupling Insert rubber ring RO154240100 between the main shaft rear bearing and the coupling Making the clearance between the main shaft bearing and the coupling 2 5 mm fit the screw No 1 to the flat section Then install the coupling Caution When engaging the respective couplings be sure to align the two position...

Page 12: ...sser cam Align engraved dot A of the intermediate presser cam with engraved dot B of the main shaft in the direction of rotation Clearance provided between section C of the intermediate presser driving arm and section D of the machine arm boss is 0 5 0 2 mm in the state that the clearance becomes narrowest lower dead point of intermediate presser 0 5 0 2 mm A B C D E Intermediate presser cam Inter...

Page 13: ...ltogether Turn the intermediate presser cam and stop it at the position where it has moved nearest to the face plate side Turn the main shaft so that engraved dot A of the intermediate presser cam is aligned with engraved dot B of the main shaft in the direction of rotation Then tighten two setscrews E If the position of the intermediate presser cam in the direction of rotation is not proper stitc...

Page 14: ...iate presser bar guide bracket 1 is 12 5 mm Needle 3 passes the center of intermediate presser 4 24 5 3 Height of the intermediate presser adjusting screw Height of the intermediate presser adjusting screw is 24 5 mm for the standard adjustment value Intermediate presser adjusting screw Intermediate presser adjusting nut 1 2 3 4 5 6 ...

Page 15: ...rmediate presser spring 笞 or intermediate presser lifting failure will occur 藺 If the tightening torque of setscrew 笙 is excessive intermediate presser bar 笆 is deformed and malfunction will occur Turn the intermedite presser adjusting screw to adjust the height and fix it with the intermediate presser adjusting nut When the height is increased the pressing pressure is decreased Caution 1 Adjust t...

Page 16: ...ding 3 Adjusting the wiper components 1 Position of the wiper The standby position of wiper 1 is approximately 45 2 mm from the top surface of throat plate Clearance provided between needle 2 and wiper 1 should be 1 mm or more when wiper 1 passes under needle 2 after thread trimming When the intermediate presser is provided make the clearance provided between intermediate presser 3 and the wiper 1...

Page 17: ...wiper and needle 2 and the wiper and intermediate presser 3 should be 1 mm or more when turning wiper 1 up to just below needle 1 If the adjustment value is excessive the lifting amount of the intermediate presser is decreased when the sewing machine stops If the adjustment value is small noise may occur during operating the sewing machine or intermediate presser lifting link 3 may be broken If th...

Page 18: ...al position of the hook driving shaft sprocket 3 Backlash of the hook shaft gear 4 Adjusting the hook shaft drive components Plane A Thrust collar small Oiling hole Face plate side Center of engraved dot Hook driving shaft sprocket Thrust collar large Oiling hole Hook driving shaft A B C D Hook driving shaft 0 1 to 0 5 mm at the position where backlash is minimized B C D 1 1 1 1 1 ...

Page 19: ... of the thrust collar large Turn the hook driving shaft by 90 with a screwdriver from the direction of arrow mark C to the direction of arrow mark D and tighten the other setscrew Adjust the backlash and tighten two setscrews 1 See the backlash of the hook shaft gear in the next item If the position of the main shaft sprocket is improper the timing belt will be deteriorated or broken If the positi...

Page 20: ...he play of the hook shaft 5 Height of the needle bar 6 Removing the oil shield plate of the hook A Engraved line for DP x 5 B Engraved line for DP x 17 18 to 25 C Engraved line for DP x 17 26 Upper engraved line 1 1 2 3 4 A B C 1 2 3 4 1 ...

Page 21: ...te 1 After the adjustment be sure to check that there is no uneven torque 2 When stitch skipping occurs in accordance with the sewing conditions adjust the height of the needle bar so as to lower it by 0 5 to 1 mm from the needle bar engraved line 4 Remove setscrew 1 and remove inner hook stopper 2 Further loosen right and left setscrews 3 and remove oil shield plate 4 At this time do not try to f...

Page 22: ...d lines Groove on inner hook Groove on throat plate 7 Needle and the engraved lines 8 Clearance between the needle and the hook 9 Inner hook stopper 0 03 to 0 1mm A When DPx5 is used When DPx17 18 to 25 is used When DPx17 26 is used 5 6 7 5 6 7 5 6 7 8 9 8 1 2 ...

Page 23: ...es not come in contact with the needle Turn the handwheel by hand in the direction of normal rotation When needle bar 5 has gone up adjust so that lower marker line 6 engraved on the needle bar aligns with the bottom end of the needle bar bushing 7 lower Fit the projection at the top end of inner hook stopper 1 to the groove on the inner hook and install setscrews 2 There is a slight play between ...

Page 24: ... 19 Standard Adjustment 10 Timing belt tension The timing belt tension is determined by the tension spring Standard belt tension 147 to 166 N Idler pulley Timing belt Tension spring 1 2 ...

Page 25: ...of arrow mark tighten setscrew 1 in the state that the belt is slowly returned and fix with setscrew 2 If the timing belt tension is excessively low the belt runs roughly and the noise will be caused If the timing belt tension is excessively high wear of main shaft or hook driving shaft will be caused Note that the time to loosen and stretch again the timing belt is within two hours If the belt is...

Page 26: ...at thread trimmer roller 2 has a clearance against the both end faces of the slit of the thread trimmer cam and smoothly enters the slit when pushing cam installing link 1 in the direction of arrow in the running section in the range of A of the thread trimmer cam Standard Adjustment Main shaft thrust collar Engraved line Main shaft Thread trimmer cam Engraved point Thread trimmer cam Main shaft C...

Page 27: ... section B of thread trimmer connecting bar 5 and when tightening further cam installing link 1 turns in the direction of arrow Then thread trimmer roller 2 which was lightly fit to the thread trimmer cam enters the slit of the thread trimmer cam Screw further thread trimmer link stopper screw 4 by half turn from the point where thread trimmer roller 2 entered the slit of the thread trimmer cam Th...

Page 28: ...upport comes in contact with the section B of the sewing machine arm stopper 4 Position of the cam installing link stopper Clearances between the cam installing link notch A and the cam installing link are as follows in the state that the thread trimmer is separated the thread trimmer stopper support comes in contact with section B of the sewing machine arm stopper a 0 3 mm b 0 5 mm or more Standa...

Page 29: ...end of thread trimmer shaft 4 with the processed section A of the sewing machine arm and tighten two setscrews 5 in the tension release arm thrust collar Push the cam installing link in the direction of arrow Then removing the play tighten setscrew 6 in the cam installing link If thread trimmer shaft 4 is mistakenly adjusted the receiving amount of front section C of the thread trimmer shaft becom...

Page 30: ...k stopper screw and move the thread trimmer magnet in the direction of arrow A Then the cam installing link moves in the direction of B At this time a clearance of 1 mm is provided between the roller attaching face of the cam installing link and the cam face of the thread trimmer cam Thread trimmer magnet arm Thread trimmer magnet Thread trimmer cam Cam installing link B A 1 mm 1 ...

Page 31: ...e of the thread trimmer cam and the roller attaching face of the cam installing link Then tighten screw 1 Thread trimmer roller enters the slit of thread trimmer cam causing thread trimmer failure or sewing machine lock Returning to the initial position of the thread trimmer is delayed and release of the tension release disk floating is also delayed causing poor tightened stitches at the sewing st...

Page 32: ...4 to 1 6 mm And the clearance provided between work section B of the throat plate and the counter knife is 0 3 to 0 5 mm 7 Height of the moving and counter knives For H and G types Height of the moving knife Height of the moving knife is set by the adjusting washer Adjust the height when thread is changed and sharpness of the knife is deteriorated Height of the counter knife Level difference A bet...

Page 33: ...ased Adjusting the height of the counter knife Correct the counter knife to adjust the height Thread spreading failure or thread trimming failure will be caused If clearance A is smaller than the specified value length of the remaining thread under the cloth is shortened If clearance A is larger than the specified value length of the remaining thread under the cloth is lengthened If the blade pres...

Page 34: ... needle hole guide and the top end of hot wire plate is 0 5 mm both in the longitudinal and lateral directions 9 Contirmation of operating timing of the moving knife Confirm as the reference of the standard adjustment value Standard Adjustment Top end of moving knie Throat plate Center of needle Top end of thread drawing section Top view Front view Moving knife Thread drawing spring 5 1 mm Top end...

Page 35: ...tening torque of setscrews 笆 to 98 to 147 N cm 10 to 15 kgf cm Confirm that the hot wire plate comes in close contact with the insulation sheet If not loosen setscrews 3 and adjust by moving the hot wire plate When loosening setscrews 3 perform the work of again Replacing the hot wire plate Remove setscrews 3 and remove the hot wire plate Replace the insulation sheet Replace the hot wire plate and...

Page 36: ... arm and the tension release link come in contact with each other in the state that the cam installing link is separated from the thread trimmer cam 6 Adjustment of the tension release components Tension release roller Section C of tension release arm roller Tension release notch Cam installing link Thread trimmer cam Setscrew 1 Tension release notch Thread trimmer cam Tension release link Tension...

Page 37: ...direction of arrow mark the clearance is decreased and it is moved in the direction of the arrow mark the clearance is increased Adjust the clearance to 1 2 mm tighten setscrews 1 and hook the tension release return spring After the adjustment the tension release arm slightly comes down by its own weight in the direction of B Move the tension release arm in the direction of A or B and make sure th...

Page 38: ...justment 7 Adjusting the sensor components 195 63 Needle hole X feed support shaft Y feed support shaft Feed plate 2 Y sensor slit 1 Sensor slit setscrew 3 Y sensor 1 Mechanical origin 2 Adjusting the Y origin sensor ...

Page 39: ...ight line Fit the point by adjusting 2 Y origin sensor and 3 X origin sensor Select Test mode No 2 origin retrieval Every time depressing the pedal the origin is retrieved Loosen 1 sensor slit setscrew and shift the position of 2 Y sensor slit to set the feed plate to the position of origin Caution After the adjustment make sure that Y sensor slit 2 does not interfere with Y sensor 3 Maximum area ...

Page 40: ... 35 Standard Adjustment 3 Adjusting the X origin sensor 1 Sensor installing base setscrew 2 X sensor 3 X sensor slit ...

Page 41: ... retrieval Every time depressing the pedal the origin is retrieved Loosen sensor installing base setscrew 1 and shift the position of X sensor 2 to set the feed plate to the position of origin Caution After the adjustment make sure that X sensor slit 3 does not interfere with X sensor 2 ...

Page 42: ...ing the positions of the X motor and the Y motor adjusting the backlash of the driving gear Felt presser Y motor X motor 8 Adjustment of the feed mechanism components 1 Adjusting the position of the X motor base Center of the hook driving shaft 1 2 3 4 1 2 ...

Page 43: ...section 2 and motor base gear section 3 is shifted When the position is shifted install the X motor base so that motor base gear section 3 is placed almost in the center of the X motor base when X feed arm 4 is aligned with the center of the hook driving shaft If the pushing is not sufficient the backlash of the gear will become large and the accuracy of the needle entry will be lowered Also it wi...

Page 44: ... 39 Standard Adjustment 3 Installing the feed plate support plate 4 Installing the feed plate Flat section End face A Fig 1 45 45 1 2 3 4 5 1 2 3 4 5 7 8 9 6 ...

Page 45: ...o Y feed support shaft 2 push feed plate 1 to feed plate support plate 4 and remove the thrust Then tighten two setscrews 5 Caution When tightening setscrews 5 move feed plate 1 in the direction of arrow and tighten the setscrews so that the position of the setscrews becomes as shown in Fig 1 Place square block 6 in the slot portion of feed plate 1 and insert X feed support shaft 7 into X feed arm...

Page 46: ... 41 1 1 1 1 37 37 30 30 50 50 71 71 54 8 Standard Adjustment 5 Installing the feed bracket Center of needle Sewing area 1 2 3 ...

Page 47: ...No 2 origin retrieval and depress the pedal to perform the origin retrieval Tighten two setscrews 1 and install feed bracket 2 Note When installing place feed plate pin 3 in the hole of feed bracket 2 If the installing dimension is not proper maximum sewing area cannot be secured ...

Page 48: ...sser cylinder knuckle 藺 When the presser goes up when the cylinder shrinks to the utmost adjust the length from the rear end of the presser cylinder to the front end of the cylinder knuckle to 87 mm 笊 87 mm Cylinder knuckle Presser cylinder 4 3 mm LK 1942 12 7 mm LK 1941 54 5 mm 2 Arm cover installing face 3 Setscrew 2 pcs 1 Bobbin winder driving wheel Main shaft Hand pulley gear Intermediate pres...

Page 49: ...the bobbin thread winder components or seizure 藺 If the clearance is excessive due to slipping of the bobbin thread winder the worn out will occur Loosen two setscrews 笊 and remove the feed bracket Remove E ring 笆 and remove knuckle pin 笳 Loosen nut 笘 and turn cylinder knuckle 笙 to adjust After the adjustment tighten nut 笘 place knuckle pin 笳 and attach E ring 笆 Install the feed bracket For instal...

Page 50: ...top end of the slider to the presser plate sheet Presser plate sheet Slider 3 Adjusting the speed controller Lowering speed of the presser can be properly adjusted Lowering speed of the left and right of 2 step presser can be adjusted to the same Left Right 1 2 3 2 3 ...

Page 51: ...f speed controller 1 located on the way of the air tube of the feed bracket and turn knob 2 counterclockwise once until it goes to the end Turn knob 2 clockwise four times and tighten nut 3 To increase the lowering speed of the presser turn knob 2 counterclockwise further than the standard adjustment position To decrease the lowering speed of the presser turn knob 2 clockwise further than the stan...

Page 52: ... 47 11 Adjustment of the draw out device components For G and Z types 1 Position of the draw out lever When the power is turned OFF draw out lever 笊 is level Standard Adjustment 2 1 ...

Page 53: ... Results of Improper Adjustment Loosen two setscrews 2 to adjust the position If the draw out lever slants the draw out amount of needle thread becomes insufficient and stitch skipping at the start of sewing or the like occurs ...

Page 54: ...54210D00 14218002 B23022050AA Not provided Z type Extra heavy weight materials DPx17 25 26 14440002 Ellipse 3X4 4 14436158 14441208 Hot wire type 14441505 Hot wire type G type Extra heavy weight materials DPx17 23 14439707 ø4 14436307 14438659 14438568 Part No Needle Needle bar Needle bar thread guide Needle hole guide Hole diameter Bobbin Bobbin case Lubricating hook Link type thread take up leve...

Page 55: ...able of the sewing conditions Note The combination of the different kinds of outer and inner hooks can be used under the special sewing conditions Example Baloon stitch occurs when the lubricating hook D is used under the conditions of ORGAN needle 24 plus cotton thread Use the outer hook only of lubricating hook A or B Standard engraved line Needle size Kind of hook Lubricating hook A 14436554 H ...

Page 56: ... registered in this ROM as well 2 Specifications Available pattern Nos 1 to 99 Available number of patterns 64 excluding service patterns Max number of stitches 10 000 stitches For the pattern No the number of DATA_ROM is preceded When the number 51 52 53 54 or 60 is overlapped the pattern in the DATA ROM is read out 3 Input device PGM 7 Main body input device exclusively used for LK 1941 42 PGM 2...

Page 57: ...ken correct data cannot be read and the error may occur E 1 E 2 E 8 2 The standard bar tacking pattern data 30 patterns of LK 1900 are stored in SYSTEM ROM When desiring to use the data set the memory switch No 3 to Calling effective for use 3 When desiring to use the data of LK 1900 including button attaching pattern other than the standard 30 patterns write the data in the standard DATA ROM by m...

Page 58: ... in unit of 100 r p m This function sets whether or not the calling of the service pattern data is acceptable Display of change of pattern No X Y scale max speed limitation and heat cutter temperature and whether or not to change these items can be set Prevention of maloperation Setting of the counter operation Production counter Adding counter Bobbin thread counter Subtracting counter Needle bar ...

Page 59: ...and the function is actuated Tension disk No 2 floating function H type optional or thread draw out function G and Z types is selected Effective ineffective of execution of automatic preparation action after turning ON the power is selected This function controls thread tension controller No 3 and inverting clamp using the inverting pattern Selection of needle bar up position stop holding mode Sta...

Page 60: ...hen thick thread is used Possible to set in unit of 50ms Effective ineffective of control of optional thread clamp device is selected OFF timing of guide cylinder of optional thread clamp device is set by the number of stitches from the start of sewing Speed of revolution of bobbin winder is set Wiper operating timing at the time of needle up position stop No 6 1 is set Selection of returning rout...

Page 61: ...mmediately after turning ON the power switch simultaneously press P 3 key and SELECT key The level moves to the service level 1 Operating method 1 How to start the memory switches READY RESET R OFF ON Keep pressing Turn ON the power switch Explanation Step Operation method Indication P 3 SELECT ...

Page 62: ...the indication No Press down FORWARD and BACK keys to change and check the contents The setting returns to the initial setting by pressing down RESET R key After setting press down READY key and put out the sewing LED Then register the contents 1 2 3 4 Ex When No 01 is indicated SEWING Sewing LED Lights up Ex When the max speed limitation is 1 500 r p m SEWING Sewing LED Put out FORWARD BACK or RE...

Page 63: ...wing LED is put out and the indication returns to No 03 Press down FORWARD or BACK key to change whether or not to call the standard pattern data The setting returns to the initial value by pressing down RESET R key Every time SELECT key is pressed the pattern No increases by one Pattern Nos 1 to 64 When the pattern No is changed to the No desired change whether or not to call the standard pattern...

Page 64: ...s up SEWING Sewing LED Put out Press down FORWARD or BACK key to select the indication No 04 Press down READY key to light up Sewing LED Press down FORWARD or BACK key to change the set value The setting returns to the initial value by pressing down RESET R key After setting press down READY key to put out Sewing LED and register Explanation Step Operation method Indication RESET R ...

Page 65: ...the indication No 99 Press down READY key to light up Sewing LED Press down FORWARD or BACK key to change the set value The setting returns to the initial value by pressing down RESET R key After setting press down READY key to put out Sewing LED and register Explanation Turn OFF the power Step 1 Operation method Indication OFF ON 2 How to finish the memory switches Turn OFF the power switch Expla...

Page 66: ...nditions will be performed and the mode will move to the continuous aging mode Output of the specified number of revolutions will be made and the actual number of revolutions will be indicated Solenoid solenoid valve status output and hot wire output will be checked Hot wire output time can be set longer than that usually used This is a mode to tentatively heat the wire for a long time Hot wire pl...

Page 67: ...indication will move to the selection of other test function Test program No will be changed by pressing down FORWARD or BACK keys Test program No will be decided by pressing down SELECT key When P 1 key and P 3 key are simultaneously pressed down the step will return to the step 5 However when test No CP 3 is selected it cannot be returned to the step 5 At this time turn OFF the power switch 1 2 ...

Page 68: ...signal The signal occurs one time during rotation of the sewing machine when the needle bar angle is between 80 and 123 AUDET Sewing machine upper dead point position signal The signal occurs one time during one rotation of the sewing machine when the needle bar angle is between 5 and 30 The aforementioned needle bar angles are those detected from the encoder of the main motor Input line Nos 7 and...

Page 69: ...ample Check the READY key Example Check the RESET R key As for the other keys refer to the input line No 1 of the above table Update of the input line No 1 to 2 State of the input line No 2 key will be indicated on LED Example Check the SELECT key Update of the input line No 2 to 3 Indicating section input line No Checking measure Explanation ...

Page 70: ...No 3 to 4 Refer to the adjustment of the sensor components Update of the input line No 4 to 5 Turn the hand pulley A in the left figure by one revolution in the direction of arrow Feed start 1 time TG 45 times Upper dead point 1 time Lower dead point 1 time Needle upper position 1 time Update of the input line No 5 to 1 Presser lifter switch Start switch Sewing machine head A Light up Indicating s...

Page 71: ...d even when the pedal switch is depressed At this time return the position to the upper position using the hand pulley Start switch FORWARD BACK or SELECT Step Indicating section Checking measure Explanation or or will be indicated according to the state of the sensor 1 2 3 JOG movement of the X Y axes can be changed by pressing down the SELECT key Depress the pedal switch and the sensor will exec...

Page 72: ... the setting moves to the automatic origin retrieual setting Setting moves to automatic origin retrieval setting by pressing down FORWARD or BACK key Setting range A0 Ineffective initial setting A1 Every 100 times A2 Every time Automatic origin retrieval is updated and setting moves to pattern No setting by pressing down READY key When setting for the first time 0 is indicated In other cases patte...

Page 73: ... pressing down FORWARD or BACK key The indication is changed to the indication of the actual value by pressing down SELECT key SPEED LED of the setting item flashes on and off The sewing machine rotates and the actual value of the number of revolutions is indicated by pressing down READY key SPEED LED of the setting item is kept flashing The sewing machine stops by pressing down RESET R key SELECT...

Page 74: ... revolutions Even while the sewing machine is rotating the number of revolutions is changed by pressing down FORWARD or BACK key The specified number of revolutions is updated by pressing down READY key SELECT Flashes The output is changed to the output of the specified number of revolutions by pressing down SELECT key SPEED LED of the setting item lights up FORWARD BACK or READY Indicating sectio...

Page 75: ...e AIR_6 14 Thread clamp wire valve AIR_8 15 Thread controller No 3 valve AIR_9 P99 output 16 Presser waiting signal External I F 17 Start waiting signal External I F 18 Bobbin thread counter over signal External I F 19 Needle thread breakage detection error External I F 20 Temporary stop error External I F 21 Thread trimming signal at the time of completion of a cycle External I F FORWARD BACK or ...

Page 76: ...he function of CP 6 is for valuation and test When it is normally used the load applied to the hot wire plate is large and the plate may be fused So do not operate this function for the normal use FORWARD BACK or 1 2 READY Indicating section Checking measure Explanation Step Output time is increased or decreased by pressing down FORWARD or BACK key Output of the specified time is performed by pres...

Page 77: ...T UP position U DET 3 Sewing machine status output This output is signals that can output the operating state of the sewing machine to the external device by 8 bit signals ACTIVE is LOW 1 Time chart Ready key After moving to sewing start point Temporary stop command Bit 0 Presser SW waiting Bit 1 Start SW waiting Bit 2 During sewing Bit 3 Bobbin thread counter over Bit 4 Thread breakage error Bit ...

Page 78: ...ror processing during sewing Bit 2 During sewing Including jump feed The signal becomes ACTIVE after the start SW has been received and is reset after completion of sewing after the presser moved to the sewing start point and has lifted Bit 3 Bobbin thread counter over The signal becomes ACTIVE when the bobbin thread counter is over and is reset when the reset key is received Bit 4 Error signal 1 ...

Page 79: ... Connector used Straight header 34P Blue of Yamaichi Denki R 1 2 Equivalent to TLP521 Vcc J48 J48 27 28 5V 71055 Fig 2 Name JUKI Part No Maker Part No Maker Remarks Socket HK014820340 UFS 34B 04 Yamaichi Denki Connector pin HP000100260 Contact 66 type for VFS Yamaichi Denki Pin with red lead wire M90325800A0 Pin with black lead wire M90335800A0 Header HK01480034A FAP 34 07 4 without screw Yamaichi...

Page 80: ...g sewing including jump feed O 12 PC E 13 PC C Bobbin thread counter over O 14 PC E 15 PC C Thread breakage detection error O 16 PC E 17 PC C Temporary stop SW ON O 18 PC E 19 PC C Other errors O 20 PC E 21 PC C Thread trimmer solenoid ON During thread trimming O 22 PC E 23 INPUT 1 Not defined i 24 25 INPUT 2 Not defined i 26 27 IN Presser SW input i 28 GND 29 IN Start SW input i 30 GND 31 32 33 3...

Page 81: ...gure periodically one time half yearly Be sure to apply grease or LOCK TITE to the respective sliding parts which are not shown in the figure when overhauling or reassembling LOCK TITE 601 LOCK TITE 601 LOCK TITE 601 LOCK TITE 601 LOCK TITE 601 LOCK TITE 601 LOCK TITE 241 Grease Bottom face ...

Page 82: ...own in the figure periodically one time half yearly Be sure to apply grease or LOCK TITE to the respective sliding parts which are not shown in the figure when overhauling or reassembling Screw part LOCK TITE 601 Grease Grease Grease ...

Page 83: ... 78 9 PRESSER DIMENSIONS 132 5 43 5 18 12 20 20 30 30 60 67 2 73 5 66 44 10 8 25 25 50 50 100 4 1 2 8 7 ø 4 AMS 206 Sewing area 7 LK 1941 42 Sewing area Origin Feed plate ...

Page 84: ... 10 HOW TO USE OPTIONALS 1 Needle cooler When synthetic thread is used and thread breakage or stitch skipping due to needle heat occurs use the needle cooler to cool needle 1 Installing the needle cooler compl 1 2 3 4 6 7 8 9 A B A ...

Page 85: ... 2 and install needle cooler compl 1 to tap A in the wiper base through washer 3 with setscrew 4 Install hand valve 6 to air tube 2 and install air tube 7 Install air tubes 2 and 7 to wiper cord 8 with three wire clip bands 9 Note 1 2 3 4 6 7 and 9 and 3 4 5 6 and 7 described on the next page are included in needle cooler asm 14225056 ...

Page 86: ... 81 7 8 P79 Connector marker J79 Caution Standard Adjustment 2 Installing the solenoid valve 1 2 3 4 5 6 B 6 7 ...

Page 87: ... there is no clearance in respective parts since air leakage occurs from the clearance Insert plug 5 into the upper joint of solenoid valve 3 and insert air tube previously described 7 of the needle cooler into the lower joint Insert solenoid valve connector asm 6 into solenoid valve 3 Insert pin contact 7 of solenoid valve connector asm 6 into the connector connector marker J79 of solenoid valve ...

Page 88: ...erting pattern automatic inverting pattern optional inverting pattern and two air output ports Use only the thread tension controller No 3 Use only the inverting clamp device Use both the thread tension controller No 3 and the inverting clamp device Note 1 Inverting clamp device is made to special order Remarks State at the time of delivery Purpose Thread tension controller No 3 only Inverting onl...

Page 89: ...No 35 with without needle cooler output of the memory switch to 1 0 Ineffective 1 effective Normally it is not necessary to change the setting since the setting at the time of delivery is 1 Refer to Instruction Manual for setting the memory switch Caution At the time of bobbin thread winding close the hand valve ...

Page 90: ...ess is partially not good due to difference in cloth thickness hitch stitch etc needle thread tension can be increased at desired position by using the tension controller No 3 1 Installing the tension controller No 3 B50192220B0 4 5 3 A 1 2 Fig 1 ...

Page 91: ...ntroller No 3 4 and install the controller almost horizontally to the machine arm with setscrew 5 Refer to Fig 1 for threading Note 3 4 and 5 only are included in tension controller No 3 asm B50192220B0 Prepare separately 3 solenoid valve PV150209000 5 plug PX500014000 and 6 solenoid valve connector asm 14204754 described on the next page ...

Page 92: ... 87 10 9 Caution P79 Standard Adjustment 2 Installing the solenoid valve Fig 2 Connector marker J79 1 2 3 4 5 6 A 6 7 ...

Page 93: ...ere is no clearance in respective parts since air leakage occurs from the clearance Insert plug 5 into the lower joint of solenoid valve 3 and insert air tube previously described 3 of the tension controller No 3 into the upper joint Insert solenoid valve connector asm 6 into solenoid valve 3 Insert pin contact 7 of solenoid valve connector asm 6 into connector connector marker J79 of the solenoid...

Page 94: ...parately available is required In addition when using PGM 20 the ROM writer is required Disk of tension controller No 3 always rises at the sewing start and sewing end and there is no limit of number of inverting points Inverting point Drive section of tension controller No 3 Tension is applied after thread tension disk is closed Inverting point Sewing start Inverting point Inverting point Drive s...

Page 95: ... No 3 is completed set No 31 of memory switch to 1 Normally it is not necessary to change the setting since the setting at the time of delivery is 1 Refer to Instruction Manual for setting of the memory switch Refer to the Instruction Manual for each input device for input change etc of the pattern ...

Page 96: ...verse sweeping wiper By using the wiper base and the wiper of the optional parts the wiper sweeping action can be changed to the reverse sweeping 3 Reverse sweeping wiper Wiper Standard Wiper base Reverse sweeping Standard Reverse sweeping 1 2 3 ...

Page 97: ...move the motor cover and install reversely the air tube connected to the solenoid valve from the wiper device Standard J05 is on the upper side J06 is on the lower side Reverse sweeping J05 is on the lower side J06 is on the upper side Adjust the position of the wiper to the same as that of standard adjustment as described below Clearance provided between the wiper and the needle is 1 mm or more A...

Page 98: ...he optional parts the wiper retains thread 2 Adjusting the thread retaining wiper C B A 22 5 mm 0 5 mm A Standard Adjustment Wiper Standard Wiper base Thread clamp wiper Thread clamp Wiper base Feeding frame 15 mm or less Top surface of throat plate 1 mm or more 4 Thread retaining wiper 1 2 3 1 2 3 1 ...

Page 99: ...r becomes smaller than the tandard adjustment value and the height of the top end of the wiper is lowered since the wiper retains the thread Accordingly the feeding frame may interfere with the wiper when the feeding frame goes up Adjust the height of the feeding frame to 15 mm or less from the top surface of the throat plate For adjusting procedure refer to the Instruction Manual for LK 1941 42 W...

Page 100: ...intly using the feed plate blank for belt and the feed plate guide for belt the sewing product can be pressed further securely 79 26 68 Standard Adjustment 5 Feeding frame components for belt LK 1941 43 5 17 5 52 2 2 50 2 2 1 Feeding frame for belt Processing line Knurl on rear face Periphery of stitching pattern Engraved line Position of feed origin Feed plate for belt Feed plate guide Sewing pro...

Page 101: ... them Caution Be sure to cut off the air supply and start the work when replacing the feeding frame Install the optional parts Feed plate blank for belt Part No 14444202 Feed plate guide Part No 14444301 Make additional processing of the feed plate blank for belt and install it on the machine in accordance with the stitching pattern Caution on additional processing Make the processing of the same ...

Page 102: ... board Turn OFF the power switch Defective MAIN circuit board Replace the MAIN circuit board Turn OFF the power switch and check whether the fan filter is clogged and the power source voltage Turn ON the power after the temperature has dropped properly Description The specified pattern No has not been registered in the data ROM The sewing pitch is beyond 10 mm Data ROM which is used is different f...

Page 103: ...m and the motor base is excessive Backlash between the X stepping motor and the motor base is excessive Motor base is excessively pressed to the X feed arm X stepping motor is excessively pressed to the motor base Friction between the X slide plate and the feed plate Correct the position of the wiper Correct the position of the wiper Lengthen the wiper ON delay time Memory switch No 45 Adjust the ...

Page 104: ...pply air pressure is low Solid type feeding frame is installed to the separate type presser foot Whole part of the feeding frame is not pressing the material to be sewn Trouble of the presser lifter solenoid Defective connection of the presser lifter solenoid cable Trouble of the solenoid valve Defective connecion of the solenoid valve cable Properly adjust the backlash in the Y stepping motor Pro...

Page 105: ...esistance of thread draw out from thread stand is large Coating thread or the like Bobbin thread tension is too high Clearance between the intermediate presser and the material to be sewn is large LK 1942 Stroke of the intermediate presser is large Working timing of the intermediate presser is not adjusted properly Decrease the sewing speed at the start of sewing Lower the needle count to be used ...

Page 106: ...too high Needle is too thin as against the kind of hook Clearance between the intermediate presser and the material to be sewn is large Hole diameter of the needle hole guide is large Perform threading again Strengthen the idle prevention spring Properly adjust the initial position of the moving knife Properly adjust the knife components Properly adjust the clearance between the needle and the hoo...

Page 107: ...the scratch and polish it with buff or replace it with a new one Replace the needle Properly adjust the thread take up spring Properly adjust the thread take up spring Install the oil shield plate Loop fall occurs Needle sways Scratches on the hook Thread enters into the hook Scratches on the needle hole guide Finish of needle eyelet is rough Thread take up spring is maladjusted Thread is entangle...

Page 108: ... due to short thread trimming at the time of thread trimming Partial catch of needle thread loop by hook Thread spreading section of the moving knife has scratches Thread is cut before trimming with the blade section of the moving knife G and H types Thread is cut before trimming with the blade section of the moving knife G and H types Bottom face of the needle hole guide has scratches Thread spre...

Page 109: ...oximately 20 Replace the needle hole guide with the ellipse needle hole guide for seat belt 6 Thread is not trimmed Sharpness of the knife is defective G and H types Sharpness is defective Z type Hot wire plate is fused Z type Moving knife does not spread threads Stitch skipping at the final stitch Worn out of the moving and counter knives Engagement of the moving and counter knives is defective P...

Page 110: ...troller No 2 Tension controller No 2 or auxiliary thread tension is floating Thread take up spring is maladjusted Selection of the needle to be used is improper Selection of the needle hole guide is improper Shape of the feed plate is defective Thread slips from the thread guide wheel of the auxiliary thread tension G and Z types Feed timing is defective Bobbin thread tension is too low Needle hol...

Page 111: ...oo fast Tension of the tension controller No 2 is too high Decrease the maximum speed Use a thinner needle or a super needle for the synthetic thread Apply silicon Use the needle cooler Polish the thread path of each component with polishing powder Replace the needle Move the thread guide A to the left Use the ellipse needle hole guide for seat belt Use a ball point needle Use a thinner needle Cha...

Page 112: ... o n n e c t o r POWER circuit board 2 B Disconnected J16 connector MAIN circuit board 2 C Fuse F3 has blown 2 D Fuse F6 has blown 3 A Disconnected J23 connector MAIN circuit board 4 A Direction of the system ROM is reverse 4 B System ROM is not correctly inserted 4 C Wiring pattern near the data ROM has broken Securely connect the connector Replace the fuse after removing the cause 10A Securely c...

Page 113: ...rd are not connected 5 1 MAIN circuit board thermostat are not connected 6 1 Rated power is not supplied 6 2 Driving power has not been supplied to the machine motor 6 3 Driving power has not been supplied 6 4 Power for the control has not beeb supplied 6 5 Encoder signal from the machine motor has not been supplied 7 1 MAIN and SERVO circuit boards are not connected 1 A Disconnected J22 connector...

Page 114: ...connected J15 connector Y feed 1 A Disconnected J18 or J26 connector MAIN circuit board 1 A Disconnected J78 connector 2 A Setting of the detection pressure is too high 2 B Sensor cannot detect Securely connect the connector Replace the sensor Replace the circuit bosrd Replace the fuse after removing the cause 8A Securely connect the connector Replace the MAIN circuit board Securely connect the co...

Page 115: ...nected J14 and J15 connectors 1 A Disconnected J12 connector 2 A Memory switch No 37 or No 38 is set to ineffective 1 Set the memory switch No 20 to 1 Connect the head grounding wire to the control box Properly adjust the position of thread breakage detection plate Replace the MAIN circuit board Securely connect the connector Check the output of test mode CP 5 and replace the solenoid valve Check ...

Page 116: ...ircuit of solenoid driving transistor 17 1 Model setting memory switch No 99 is wrong 18 1 Hot wire plate is not heated at all 18 2 Temperature of the hot wire plate is not raised 19 1 Solenoid valve cannot be turned ON 1 A Model setting memory switch No 99 is wrong 1 B Heater unit and control box are not connected J46 J45 and J87 1 C Fuse of the heater unit has blown 1 D Hot wire plate has fused ...

Page 117: ...or E8 is occasionally indicated 22 E6 cannot be released 20 1 Wiper operation mode is incorrect 20 2 Solenoid valve wiper switch M A I N c i r c u i t b o a r d a r e n o t connected 20 3 Failure with the circuit board 21 1 Setting of SW1 1 of the MAIN circuit board is wrong 21 2 Defective pattern data 22 1 MAIN circuit board safety switch are not connected 22 2 Safety switch lever is not turned O...

Page 118: ...J23 26P J44 2P J20 RED 3P J21 YELLOW 3P J22 4P J27 2P J11 30P J16 8P J48 I F 34P J25O P INPUT 8P J1 WHITE 6P J15 BLUE 6P J1 BLACK 2P J53 RED 2P J55 BLUE 2P J13 WHITE 2P J59 YELLOW 2P J47 10P J17 20P J46 2P J49 14P External I F X PM Y PM TRM SOL T REL SOL AW 2D J79 Solenoid valve relay cable asm Solenoid valve cable asm Heater switch asm J45 Heater transformer asm Heater unit asm TERMINAL 4P HEATER...

Page 119: ...5AT 5AT HEATER CONTROLER 4 5 V PURPLE FG 2A P85 2 1 2 1 MARKING LIGHT J37 5 4 3 6 7 10 1 2 8 9 5 4 3 6 7 10 1 2 8 9 P37 RED 5 V YELLOW 24 V ORANGE 36 V BLACK GND BLACK GND BLUE GND WHITE 85 V WHITE 85 V P16 4 3 5 6 7 8 1 2 4 3 5 6 7 8 1 2 J16 J33 1 2 P33 1 2 ORANGE VH BLACK VH G P9 1 2 1 2 J9 J36 1 2 3 4 1 2 3 4 P36 YELLOW 24 V BLACK GND WHITE OVC BLACK GND P6 J6 1 2 3 4 1 2 3 4 J34 1 2 3 1 2 3 P3...

Page 120: ...URPLE FG 2A P85 2 1 2 1 MARKING LIGHT J37 5 4 3 6 7 10 1 2 8 9 5 4 3 6 7 10 1 2 8 9 P37 RED 5 V YELLOW 24 V ORANGE 36 V BLACK GND BLACK GND BLUE GND WHITE 85 V WHITE 85 V P16 4 3 5 6 7 8 1 2 4 3 5 6 7 8 1 2 J16 J33 1 2 P33 1 2 ORANGE VH BLACK VH G P9 1 2 1 2 J9 J36 1 2 3 4 1 2 3 4 P36 YELLOW 24 V BLACK GND WHITE OVC BLACK GND P6 J6 1 2 3 4 1 2 3 4 J34 1 2 3 1 2 3 P34 RED BLACK MAIN PCB SERVO PCB J...

Page 121: ...J56 3 2 1 P21 YELLOW 5 V Y ORG GND 1 2 3 RED WHITE BLACK 5 V Y ORG GND J57 3 2 1 P4 WHITE 5 V DIR GND 1 2 3 RED WHITE BLACK 5 V DIR GND J58 3 2 1 P22 WHITE TH BRK GND EM STP GND 3 4 1 2 BLACK WHITE BLACK TH BREAK N EM SW NC SW NC SW COM P59 BLACK THM THM SCN 1 2 WHITE BLACK THM NC P44 RED SAFE SW GND 1 2 SAFE SW NC ...

Page 122: ...0 P79 J79 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK RED BLACK WHITE BLACK P91 24 V AIR OPRE R N P92 24 V AIR OPRE L N P93 24 V AIR IP N P94 24V NEEDLE COOLER P95 24 V AIR TEN 1 N P96 24 V AIR CLUMP1 P80 1 2 1 2 J80 WIPER SW P97 24 V AIR WIPER P98 24 V AIR CLUM...

Page 123: ...ELLOW 36 V SOL N 1 2 WHITE BLACK SOL 6 9 Ω J29 AMS J19 PRESS R SW RTN PRESS R SW SCN PRESS L SW RTN PRESS L SCN OPTION R SW RTN OPTION R SW SCN OPTION L SW RTN OPTION L SW SCN START SW RTN START SW SCN 1 6 2 7 3 8 4 9 5 10 1 6 2 7 3 8 4 9 5 10 BROWN BLUE RED PINK ORANGE GLAY YELLOW WHITE GREEN BLACK P101 P102 P103 P104 P105 P1 P2 P3 P4 3 PEDAL PK 47 PRESS R SW NO PRESS L SW NO OP SW NO START SW NO...

Page 124: ...14 2 4 6 8 10 12 15 3 1 5 7 9 11 13 14 2 4 6 8 10 12 15 J29 P8 U V V 1 2 3 RED WHITE BLACK FG YELLOW GREEN P28 1 2 3 4 1 2 3 4 LIGHT GREEN RED YELLOW ORANGE GREEN LIGHT BLUE WHITE BLACK BLACK J28 RED YELLOW BLACK YELLOW GREEN FG FG ENCODE SERVO MOTOR P14 1 5 3 2 6 4 ORANGE WHITE BLUE RED BLACK YELLOW X PULSE MOTOR P15 1 5 3 2 6 4 ORANGE WHITE BLUE RED BLACK YELLOW Y PULSE MOTOR ...

Page 125: ...24 V HEAT CUTTER N 1 2 P87 AC60 V AC60 V NC 1 2 3 HEATER UNIT ASM SSR 3 4 LOAD LOAD 1 2 FUSE 5AT FUSE 5AT d a c b P45 J45 1 2 1 2 WHITE WHITE HEAT TR TERMINAL 4P WHITE YELLOW BLUE RED 1 2 3 4 AC3V 20A 1 AC3V 20A 1 AC3V 20A 2 AC3V 20A 2 HEATER ...

Page 126: ...overed in this engineer s manual is subject to change for improvement of the commodity without notice 04 09 Printed in Japan E R INTERNATIONAL SALES H Q 8 2 1 KOKURYO CHO CHOFU SHI TOKYO 182 8655 JAPAN PHONE 81 3 3480 2357 2358 FAX 81 3 3430 4909 4914 Copyright 狡 2000 2004 JUKI CORPORATION All rights reserved throughout the world ...

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JUKI LK-1941, Engineer'S Manual

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