Ultra 500/750/1000 Single Cavity Valve Gate 2.0 Service Procedure: 521-0 . Product Affected Reference Molds Revision History Rev. No. Comments Date 0 Initial release 2006-April-28 ©2006 Husky Injection Molding Systems Ltd. This document is the property of Husky Injection Molding Systems Ltd. and the information herein is strictly confidential. This document shall not be reproduced or used without the written permission of Husky Injection Molding Systems Ltd.
Summary: Follow this procedure to: - perform preventative maintenance - disassemble the Single Cavity Valve Gate (SCVG) unit - replace the valve stem - replace the seals - reassemble the SCVG unit Estimated Hours: 2 hours* Special Tools Required: Reverse taper stem removal tool (HPN: 3512615). Parts List: HPN Description Qty 644751 High temperature anti-seize compound 1 534526 High temperature grease 1 1. Perform Lockout/Tagout. Refer to Machine Manual for details.
Weepage Every 250,000 cycles the SCVG unit should be disassembled, any weepage in the stem retainer well should be cleaned out, and all seals replaced (see Seal Replacement). NOTE: Refer to the section entitled "Disassembly" for instructions on how to disassemble the SCVG unit. Disassembly 1. Remove the Locating Ring (not shown). NOTE: Jacking screws are provided if necessary. 3. Pull the unit from the mold. 2.
19. Pull the Melt Channel (M/C) reducer (item 36) out of the air plate (item 39). 20. Pull the nozzle (item 23) out of the air plate (item 39). 21. Remove the weep fitting (item 25) from the sprue body (item 27) to enable removal of the sprue body heater (not shown). 22. Clean all parts after disassembly. Make sure the sealing and contact surfaces are free of plastic, grease, dirt, and dust. 23.
Seal Replacement All seals should be replaced each time the unit is disassembled to ensure optimal sealing. Seal life is rated at 250,000 cycles or 6 months (whichever occurs first). Husky recommends having a spare Preventative Maintenance (PM) kit on hand to facilitate easy seal replacement. NOTE: The following PM kits are available: • • • SCVG 500 PM kit (HPN: 3509935) SCVG 750 PM kit (HPN: 3509936) SCVG 1000 PM kit (HPN: 3509937) Stem Removal 1. Obtain a stem removal tool (Figure 2, HPN: 3512615).
2. Loosen the four SHCS securing the sprue bushing insert and remove them from the extruder pad. 3. Loosen the four SHCS securing the extruder pad and remove them from the sprue body. 4. Loosen the two SHCS securing the stem retainer to the stem slider. 5. Remove the front ring of the nozzle heater. 6. Remove the nozzle heater snap ring. 7. Loosen the nozzle tip.
8. Insert the valve stem removal tool into the injection side of the sprue body. 9. Gently tap the valve stem removal tool ensuring contact with the stem at all times, until the stem is freed from the sprue body.
Reassembly 1. Unpack and clean all of the components. Compare the nozzle housing and valve stem to design prints and BOM. Make sure that the sprue body and nozzle housing melt channels are clean and free of burrs. Compare all of the components to the assembly drawing for proper items and quantity. 2. Attach the name plate to the air plate using the supplied rivets. 3. Place the air plate in a vise (Figure 5) with the arrow facing down (i.e. boss down/pocket up). Figure 5 Air Plate 4.
5. Install the Grafoil air seals (Figure 7, item 1) into the air plate (item 2) and M/C reducer (item 3). 3 1 2 Figure 7 Air Plate 1. Grafoil Air Seal 2. Air Plate 3. M/C Reducer 6. Install the sprue body retaining tabs (Figure 8, item 1) into the sprue body. Finger tighten into place. NOTE: Older revisions may not have tabs. 1 1 2 1 Figure 8 Sprue Body 1. Sprue Body Retaining Tabs 2.
7. Place the sprue body (Figure 9, item 1) onto the air plate (item 2). Make sure that the Thermocouple (T/ C) hole (item 3) on the sprue body lines up with the air plate T/C groove (item 4, for the T/C wire leads). 1 3 2 NOTE: The Piston Rods may need to be moved into alignment with the holes in the insulator to get the insulator to seat against the sprue body. 4 Figure 9 Sprue Body and Air Plate 1. Sprue Body 2. Air Plate 3. T/C Hole 4. T/C Groove 8.
10. Assemble the stem slider (Figure 12, item 1) and connecting rods (item 2). 1 2 NOTE: The stem slider is assembled flat side down. 2 Figure 12 Stem Slider and Connecting Rods 1. Stem Slider 2. Connecting Rods 11. Tilt the sprue body 45 ° in vise as shown (Figure 13).
1 12. Install the valve stem (Figure 14, item 2) into the nozzle housing (item 1) reverse taper side first, until the reverse taper bottoms out on the sprue body and the stem head (item 3) protrudes out of the pocket (item 4). 2 3 4 Figure 14 Valve Stem and Sprue Body 1. Nozzle Housing 2. Valve Stem 3. Stem head 4. Pocket 13. Assemble the stem retainer (Figure 15, item 1) onto the stem head (item 2) and seat it onto the stem slider. 1 2 Figure 15 Stem Retainer and Stem Head 1. Stem Retainer 2.
14. Apply anti-seize compound to the stem retainer screws (Figure 16, item 2) and torque to 7lb-ft (9.49 Nm). Install a lock washer or star washer (item 1). Make sure the valve stem assembly moves freely. 1 12 Figure 16 Stem Retainer Screws and Valve Stem Assembly 1. Lock Washer 2. Stem Retainer Screws 15. Install the extruder pad (Figure 17, item 1) onto the sprue body (item 2). Make sure the assembly bolt holes line up correctly. 1 2 Figure 17 Extruder Pad and Sprue Body 1. Extruder Pad 2.
16. Apply anti-seize compound to the extruder pad (Figure 18, item 1) and sprue body SHCS. Install and torque to 32 lb-ft (43.4 Nm). 17. Rotate the SCVG assembly 180 ° in a vise (Housing up). 1 Figure 18 Rotating the SCVG Assembly 1. Extruder Pad 18. Install the piston o-rings (Figure 19, item 1) onto the piston. Lubricate all o-rings with silicon o-ring lubricant. 1 Figure 19 Piston O-Rings 1. Piston O-Rings 19. Install the o-rings (Figure 20, item 1) onto the cylinder insert (item 2).
20. Install the o-rings (Figure 21, item 1) onto the air plate boss (item 2). Lubricate all o-rings with silicon o-ring lubricant. 1 2 Figure 21 Installing the O-Rings onto the Boss Plate 1. Piston O-Rings 2. Air Plate boss 21. Install the cylinder insert (Figure 22, item 1) into the piston. Make sure the cylinder insert does not cover the inner connecting rod retaining groove. NOTE: The chamfer side of the cylinder insert is inserted opposite the piston rod retaining slots (item 2).
1 23. Slide/push the cylinder insert (Figure 24, item 1) down over the air plate boss o-ring. 2 3 24. Lubricate the cylinder inner walls with o-ring lubricant and assemble onto the air plate (item 4). Align the air open lines (item 3) by making sure the arrows (item 2) are pointing to each other. 4 Figure 24 Air Open Line Alignment 1. Cylinder Insert 2. Arrows Plate 1 1 3. Air Open Lines 1 4. Air 25. Apply anti-seize compound to the cylinder SHCS (Figure 25, item 1) and install.
27. Install the nozzle tip (Figure 27, item 1) and torque to specification (35-40 lb-ft/47.5-54.2 Nm). 1 Figure 27 Nozzle Tip 1. Nozzle Tip 28. Rotate the SCVG over 180 ° in a vise (sprue body facing up). 29. Place/fit the sprue body T/C into the sprue body (Figure 28, item 1) using small electrical pliers. Remove the sprue body T/C (item 2) to facilitate sleeve installation. 1 2 Figure 28 Sprue Body T/C 1. Sprue Body 2.
30. Install the sleeve with the two M4 FHS (Figure 29, item 1 - finger tighten). 31. Apply Teflon tape to the air fittings (item 2) and install. 1 12 Figure 29 Air Fittings 1. M4 FHS 2. Air Fittings 32. Install the pre-fitted T/C (Figure 30, item 1) into sprue body. 1 Figure 30 Sprue Body T/C 1. Pre-fitted T/C 33. Install the sprue body heater onto the sprue body. Make sure the retainer weep fitting hole in the heater (Figure 31, item 1) aligns with the sprue body installation.
34. Install the heater retainer/weep fitting (Figure 32, item 1) using an M6 Allen key. 1 Figure 32 Retainer Weep Fitting 1. Heater Retainer/Weep Fitting 1 35. Install the sprue bushing insert into the sprue body. Make sure all four counterbores align with the sprue body taps. 36. Apply anti-seize compound to the four M6 SHCS (Figure 33, item 1) and install onto the sprue bushing insert. Torque to specification per assembly drawing. Figure 33 Sprue Body 1. M6 SHCS 2 37.
39. Install the nozzle T/C (Figure 35, item 2) and bend the leads to avoid getting pinched between the cavity plate and the manifold plate. 1 40. Install the front ring (item 1 - finger tighten). 2 Figure 35 SCVG Assembly 1. Front Ring 2. Nozzle T/C 41. Prepare the SCVG for shipment (Figure 36): 1 • • • 2 3 Figure 36 Completed SCVG Assembly 1. Heater Leads 2. Nozzle Tip Cap 3.
Table 1 HGT-50 Torque Specifications for SHCS Sample Torque Chart • Torque Size Nm lb ft M4 3 2.2 M5 6.2 4.6 M6 10 7 M8 25 18 M10 53 40 M12 95 70 M14 130 95 M16 220 160 M18 270 200 M20 390 290 M24 660 490 M30 1300 960 M36 2300 1700 M42 3700 2700 M48 5500 4000 For a comprehensive listing of torque values for other fasteners and fittings, refer to the Machine Manual.
