công nghệ SMT điều chỉnh màn hình máy dán ASM adjustable screen mount

OVERVIEW Screen Depth Adjuster Auto Screen Loader SemiAuto Screen Loader ELECTRICAL SCHEMATIC ADJUSTMENTS AND SETTINGS Screen Depth Adjuster Auto Screen Loader REPLACEMENT PROCEDURES Chase Rail Assembly Screen at Centre Sensor Cable Assembly CALIBRATIONS Chase to Table Level Associated Calibrations and Adjustments

CHAPTER 15 ADJUSTABLE SCREEN MOUNT (ASM)

OVERVIEW

Figure 15-1 ASM Overview

2 Rear Web Assembly (2 positions) 10 Screen Support Plate (2 positions)

4 Screen Clamp Pneumatic Cylinder (2 positions) 12 Screen Guide Strip

1

2

3

4 5 6 7

8

9 10

11 12

13

14

15

16

Figure 15-2 Auto Screen Loader Overview

1 Squeegee Drip Tray Mechanism 6 Squeegee Drip Tray Actuator

4 Auto Screen Loader Actuator Retracted Sensor 9 Auto Screen Loader Actuator Extended Sensor

5 Screen Position Sensor

3 4

5 6

7

View on Rear Underside of Squeegee Drip Tray Mechanism

NOTE Squeegee drip tray removed for clarity.

There are three methods for housing and securing the stencil in the machine, the first is a fixed width system and is described in the Cast C Chase chapter, the second is also a fixed width system and is described in the Machined C Chase chapter, the third is an adjustable width system and is described in this chapter

The ASM module provides a receptacle for the stencil, which is clamped in the correct position for printing operations The module width can be easily adjusted by an operator to accommodate stencils from the standard 29 inches square through to 12 inches square with 250mm belt support plates and board clamps fitted or 29 inches square through to 23 inches square with 500mm belt support plates and board clamps fitted The stencil image can be front or centre justified

The pneumatic push buttons located on the inside of the front left and right hand web assemblies are operated, releasing all four web assemblies on the front and rear rail assembly guide shafts Releasing the web assemblies allows the user to adjust the position of the left and right hand chase rail assemblies, to accommodate for the appropriate size stencil

The stencil is loaded from the front of the machine and slid into the machine along the top of stencil support plates Three stencil location leaf springs, located in the right hand chase rail assembly, ensure that the stencil is held in the correct location for printing, against the stencil guide strips on the left hand chase rail assembly

The ASM is a floating assembly mounted on a bearing set The stencil is clamped in the ASM using pneumatically activated flaps that clamp the stencil

to the stencil support plates

The ASM is positioned to align the stencil to the correct printing position During printing the ASM is pneumatically clamped to the left and right printhead assemblies, to maintain the aligned position, by the stencil alignment module (for further details refer to the Screen Alignment Module chapter in this manual)

A screen at centre, through beam opto (long throw type), sensor consisting of

a transmitter and a receiver (Tx/Rx) is used to detect the presence of a stencil

in the ASM

There are three methods used for achieving correct position of the stencil within the ASM:

• Screen Depth Adjuster

• Auto Screen Loader

• Semi-Auto Screen Loader

NOTE

1 Only one of the above items would be fitted to the machine at any one time

2 Auto Screen Loader and Semi - Auto Screen Loader options are not available

NOTE For further information on setting the screen depth adjuster, refer to Screen Depth Adjuster in the Adjustments and Settings section of this chapter.

Auto Screen

Loader

The auto screen loader (ASL) accurately positions the stencil/screen in the chase The asl is incorporated into the squeegee drip tray mechanism which is secured beneath the print carriage, therefore the drive is provided by the print carriage drive system

Initially the stencil is manually loaded and the front printhead cover is closed

When Load Screen is selected on the MMI, the asl is driven forward by the print

carriage to locate the rear edge of the stencil Once located, the asl is driven further forward allowing the asl lever to clear the inner face of the rear frame of the stencil The lever is driven down and the print carriage is reversed pulling the stencil to the rear of the chase The lever is retracted and the stencil change mechanism is driven rearwards allowing the lever to clear the rear face of the stencil The lever is lowered and the print carriage is driven forwards, pushing the stencil to the correct position Once the stencil is registered in the correct position for printing, the lever is retracted and the stencil is secured in position

Semi-Auto

Screen Loader

The semi-auto screen loader (S-ASL) positions the stencil after the operator has placed it in the chase The screen loader mechanism is incorporated into the squeegee drip tray mechanism which is secured beneath the print carriage, therefore the drive is provided by the print carriage drive system

When Load Screen is selected on the MMI, the s-asl is driven forward by the

print carriage to the correct load position The operator opens the printhead cover and loads a stencil into the machine until it abuts the s-asl lever This is the correct load position for the stencil If the stencil is not the correct one, the operator can unload it and replace it with the correct stencil The MMI posts a panel that questions the validity of the stencil after the cover is closed The

unload sequence is instigated by the operator selecting Unload Screen The

printhead cover is opened and the stencil is manually removed

ADJUSTMENTS AND SETTINGS

ADJUSTMENTS AND SETTINGS

Screen Depth

Adjuster

The stencil/screen depth adjuster has two scales as follows:

The rear of stencil to front of image scale, marked on the top of the screen depth adjuster, can be used for either centre justified or front justified stencils The scale has both imperial and metric units as follows:

• Metric - 150mm to 650mm

• Imperial - 6 inches to 26 inchesWhen using this scale it is set to the rear of stencil to front of image value The figure below shows this measurement for both centre and front justified stencils

Figure 15-3 Rear of Stencil to Front of Image Measurement

REAR OF STENCIL

TO FRONT OF IMAGE CENTRE JUSTIFIED IMAGE SIZE

650 622 600 550 500 450 400 350 300 250 200 150

6 8 10 12 14 16 18 20 22 24 26

0 4 8 12 16 20

Rear of Stencil to Front of Image Scale

Centre Justified Image Size Scale

Front Justified

Rear of Stencil to Front of Image

Centre Justified

NOTE Rear of stencil to front of image is measured from the rear face of the screen frame to the front edge of the image.

Rear of Stencil to Front of Image

ADJUSTMENTS AND SETTINGS

The centre justified image scale, marked on the side of the screen depth adjuster, can only be used for stencils that are 29 inches by 29 inches with a centre justified image For other stencil sizes with a centre justified image, the Rear of Stencil to Front of Image scale must be used

When using the centre justified image scale, the stencil depth adjuster is set to the board width value The scale has both imperial and metric units as follows:

• Metric - 0mm to 508mm

• Imperial - 0 inches to 20 inches

To set the stencil depth adjuster, use the following procedure:

1 Release the locking adjustment knob by turning it anti-clockwise

2 Set the measurement guide to either:

a The rear of stencil to front of image value, on the top scale, for either centre or front justified stencils

Left Hand View on Screen Depth Adjuster

Locking Adjustment Knob Measurement Guide

REAR OF STENCIL CENTRE

JUSTIFIED IMA GE SIZE

ADJUSTMENTS AND SETTINGS

Auto Screen Loader

Stencil Position

Sensor 1 Position a stencil in the machine so the rear stencil frame is beneath the screen position sensor

2 Using a potentiometer trimming tool adjust the sensor sensitivity clockwise until the sensor test LED extinguishes

anti-3 Turn the sensor sensitivity clockwise until the sensor test LED illuminates

4 Turn the sensor sensitivity clockwise a further half turn

5 Move the rear stencil frame backwards and forwards under the sensor to ensure that the test LED is only activated by the stencil frame

Screen Frame Screen Position Sensor

Screen Screen Frame

REPLACEMENT PROCEDURES

REPLACEMENT PROCEDURES

Chase Rail Assembly

WARNING BOARD CLAMPS EXTREME CARE MUST BE EXERCISED WHEN WORKING IN THE TOOLING AREA OF THE MACHINE TO AVOID INJURY THE FOILS ON THE FRONT AND REAR BOARD CLAMPS ARE VERY SHARP.

WARNING COMPRESSED AIR COMPRESSED AIR SHOULD NEVER IMPINGE UPON THE BODY PORTS, PIPES, ETC MUST NEVER BE BLOCKED BY HAND BEFORE CONNECTING OR DISCONNECTING ANY PNEUMATIC COMPONENTS, ENSURE THE COMPRESSED AIR SUPPLY HAS BEEN DISSIPATED AND DISCONNECTED FROM THE MACHINE.

Removal 1 Select Shut Down.

2 Select Continue.

3 Switch the mains isolator to OFF.

4 Disconnect the pneumatic supply to the machine

5 Open the front printhead cover and centralise the chase rail assemblies

6 Remove the two web assembly bracket securing screws

7 Tilt the web bracket forward to expose the pneumatic pipes

REPLACEMENT PROCEDURES

8 Disconnect the following pneumatic pipes shown in the graphic below:

9 Disconnect from the underside of the chase rail width scale assembly the

pneumatic pipe marked Rail Lock - Front.

10 Uncouple from the tube clip the pneumatic supply pipe to the Rail Lock -

Front (disconnected in Step 8).

REPLACEMENT PROCEDURES

15 Lift the rear end of the chase rail assembly clear of the rear web assembly Carefully feed the electrical connector and pneumatic pipe through the access hole in the rear web assembly

16 Replace the chase rail assembly onto the rear web assembly ensuring the electrical cable and pneumatic pipe are not trapped

17 From the front of the machine carefully lift out the chase rail assembly ensuring the electrical cable and pneumatic pipe does not snag on any part

of the machine

Fitment 1 Carefully place the chase rail assembly onto the front and rear web

assem-blies from the front of the machine, ensuring the pneumatic pipes and electrical cables are not trapped under the chase rail assemblies

2 At the rear web assembly, lift the end of the chase rail assembly and first, thread the electrical cable and subsequently the pneumatic pipe through the access hole in the web

3 Loosely assemble the chase rail securing bolts (in seven positions) to the front and rear web assemblies

REPLACEMENT PROCEDURES

4 At the rear web assembly, tighten the two horizontal chase rail securing bolts until the outer face of the chase rail just touches the web face

NOTE The two rear web horizontal chase rail assembly securing bolts must not be fully tightened at this juncture otherwise, damage to the machine may occur.

5 Fully tighten the vertical chase rail securing bolt and subsequently complete the tightening of the two horizontal rear chase rail securing bolts

REPLACEMENT PROCEDURES

6 Route the pneumatic supply pipe and electrical cable to the rear web connections Fit the loom and pipe to the appropriate connectors and secure the electrical loom with a cable tie

7 At the front web assembly, fully tighten the four chase rail securing bolts

8 Connect the Screen Clamps - Off and Screen Clamps - On pneumatic

pipes to the quick release pneumatic connections shown below

REPLACEMENT PROCEDURES

9 Thread the Rail Lock - Front pneumatic pipe through the slot in the chase

rail width scale assembly and connect the pipe to the front web assembly pneumatic connection Ensure the pipe is secured into the pipe clip

10 Connect the rail lock pneumatic pipe to the push button valve on the web bracket assembly

11 Secure the web bracket assembly with the two securing screws

12 Reconnect the electrical and pneumatic power to the machine and check for air leaks

13 Press and hold the relevant push button valve and ensure the front and rear web assemblies release allowing the chase rail position to be adjusted Release the button valve and ensure the chase rail is now clamped in position

14 Power up the machine and press the System button to initialise.

15 Select Maintenance.

REPLACEMENT PROCEDURES

16 Select Diagnostics.

17 Use Next or Previous to highlight Screen Change.

18 Select Select Module.

19 Use Next or Previous to highlight Toggle Screen Clamps.

20 Select Run Diagnost repeatedly and ensure the flap assemblies extend

and retract correctly

1 Place the chase rail assembly on a level surface with the stencil support plate uppermost Unscrew the nine M3 countersunk stencil support plate retaining screws and remove the plate

2 Remove the screen at centre M3 button headed retaining screw from the centre of the sensor body

3 Release the sensor loom from the ‘P’ clip fitted adjacent to the pneumatic cylinder pulley

REPLACEMENT PROCEDURES

4 Remove and discard the sensor loom

5 Fit the replacement sensor to the chase rail assembly and secure with the M3 button headed screw

6 Fit the ‘P’ clip to the sensor loom and secure with the pan headed screw Ensure the loom runs beneath the cable assembly

7 Feed the loom through the channel of the chase rail assembly

8 Refit the stencil support plate and secure with the nine M3 countersunk retaining screws

9 To refit the chase rail assembly to the machine (see Chase Rail Assembly - Fitment procedure earlier in this section

View on Underside of Chase Rail Assembly (Stencil Support Plate Removed)

'P' Clip Screen at Centre Sensor

REPLACEMENT PROCEDURES

Cable Assembly To replace the cable assembly the appropriate chase rail assembly is to be

removed from the machine (see Chase Rail Assembly - Removal procedure earlier in this section)

Removal 1 Place the chase rail assembly on a level surface with the stencil support

plate uppermost Unscrew the nine M3 countersunk stencil support plate retaining screws and remove the plate

2 Turn the chase rail assembly through 90° Unscrew the stencil guide strip M3 pan head retaining screws and remove the stencil guides for access

3 Rotate the chase rail assembly until the flap assemblies are uppermost Loosen the flap cover bracket retaining screws and remove the four flap covers

4 Lever the cable retainers from the topmost cable pulleys

5 Unscrew the two cylinder cover securing screws and remove the cover to gain access to the cable retainer bracket Remove the two pan headed retaining screws, the bracket and release the cable end

Cable Retainer Bracket

Pulley Retaining Pin

View on Chase Rail Assembly

REPLACEMENT PROCEDURES

8 Remove the cable end from the retaining slot in the chase rail assembly

9 Un-thread the cable assembly from the cable pulleys and cylinder pulley

Fitment 1 Fit the end of the new cable assembly to the retaining slot in the chase rail

(in three positions)

If a DEK Test Plate is required, contact DEK Customer Support before mencing.

com-The chase to table level is checked by measuring down to 5 points on the rising table surface from the DEK Test Plate which simulates a screen fitted in the chase

A datum reading is taken from the centre hole E, the range of readings must not exceed 0.15mm of the datum

Figure 15-4 Chase to Table Level Setting

Depth Micrometer

Test Plate Adjustable Screen Mount