PneumobotSprue Picker Robot

Contents

• Problem Statement

• Plastic Injection moulding

• Robotics

• Automation 2012 visit & IATF 2013

• Design and analysis

• Pneumatics and electricals

• Fabrication

Problem Statement

1. To Enhance the productivity in IMM industry using

automation and resolve issues regarding workers.

2. To perform pick and place operation within 8 seconds from IMM to Granulator.

Purpose of Project

1. Consistency

2. Fast Cycle time

3. Less Labor Cost

4. Product Hygiene

5. Safety Issue

6. 2nd level Automation

7. Continuous Operation

8. Productivity

Abstract

• Electro-pneumatic robot for automation in plastic IMM having mechanical gripper to remove sprue (waste component) from the mold and placing it into Granulator.

• A linear and rotary pneumatic actuator will be used to give required motions.

• Mitre Bevel gear to transmit power and torque. Linear nylon made slider for easy sliding motion

.

Methodology

1. Robot models and IMM study2. Exhibitions3. Industry survey4. Brain storming 5. Pneumatics and Electricals.6. Design and material selection7. Analysis8. Design review and synthesis9. Fabrication10. Testing and results

Process flow in IMM :

Parts of Horizontal Injection moulding machine

*

Schematic of thermoplastic Injection molding machine

Arburg machine specifications :

Clamp Tonnage / Machine

Tie Bars ClearanceHxV (mm)

Injection WeightPS. g (oz)

Min - Max Mould Height. (mm)

Opening Stroke Max (mm)

25 Arburg 221 32 (1.13) 150 - 300

200

40 Kawaguchi 275 x 24573 (2.57)

150 - 250230

*55 Arburg 320 x 320 78 (2.5) min 225 350

*88 Arburg 370 x 370 89 (3.4) min 200 450

*110 Arburg 420 x 420 153 (5.9) min 250 575

125 Kawaguchi 435 x 375226 (7.97)

180 - 400355

140 Kawaguchi 435 x 375260 (9.17)

180 - 400355

175 Kawaguchi 445 x 445372 (13.1)

250 - 450400

*220 Sumitomo 610 x 560532 (18.8)

250 - 580510

265 Kawaguchi 550 x 550649 (22.9)

200 - 550500

*280 Sumitomo 685 x 635733 (25.9)

300 - 620 580

300 Dongshin 685 x 580970 (34.1)

300 - 680 600

Component with sprue Component without sprue

Proposed designs1. Guide way cartesian model

2. Articulated type (scara,revolute)

3. Cartesian type

4. Swing arm type (vertical)

5. Swing arm type (horizontal)

Types of products :

Robot Applications inside & outside the Mold

Two Plate Mold

Sprue Picking Only

Sprue and Parts Removal

Part Removal

Sprue Picking

with Part

Dropping

Sprue Picking

with products

connected

Part removal

with the sprue

or without the

sprue

Simple Operation

Taking out the

Sprue from the

mold and

dropping it.

( Inside of the

mold, Conveyor ,

Box )

Remove Parts, 90deg Rotation and Placing

the parts ( Conveyor, Box)

Mounting Position of Robot Pick Operation

Arm : Double arm or Single Arm

Descent Position : Nozzle or Clamp

Motion Style : U or L

Operation : Vacuum, Chuck, Gripper

Robot case-study models :

1. Artic RSL

2. Yushin Hop 5

3. Sailor RX-8

4. Wittmann Battlefeld w702

5. Sepro S3 picker

6. Arburg integral picker7. Phoenix

Complete Process Chart

Yes

No

Raw material (RM) for

coloring and mixing

Arrival of Raw

materials & mould

Mould on moulding

machine using hoist

RM feed to the Hopper

Moulded components

for finishing

Sprue & defectives

to granulator

Component package

and storage

Dispatch of Component

Start

End

Is product defective?

Catia model of Picker machine on fixed platten

Drafted image

Cylinder selection

Cylinder selection :

Cylinder selection from Janatics Pneumatics catalogue through requirement of std stroke, bore and force. 3 A52 magentic cylinders and 1 A03 series male threaded cylinder for gripper.

Dimensions and mechanisms of robot were finalized from cylinder selected.•Swing Cylinder Stroke 50mm ,Diameter 25mm •Kick Cylinder stroke 80mm ,Diameter 20mm•Vertical cylinder stroke 160mm ,diameter 16mm

•Gripper cylinder stroke 20mm, diameter 16 mm.

Mechanisms

1. Quarter turn pulley2. Power screw3. Electric motor4. Rack and pinion5. Pneumatic 4 piston actuator6. Spiral Bevel gear pair

Design considerations :

We have used factor of safety of above 3 everywhere except in caseof gear we have fos = 2.4

Our design is safe at 8 bar pressure. and gear pair fos is 1.2 at 8 bars.

Solenoid valves can operate at max of 8 bar pressure

All other pneumatic component can sustain 10 bar pressure.

Design innovations

Mitre bevel gear eliminated the need for wrist rotation of gripper plus reduced 1 movement of vertical cylinder.

Arc bracket provides rotation on either side.

Self made slider from nylon on Aluminium was made.

Gripper was developed from compact cylinder.

Analytical design and analysis

Our calculations predict that each cylinder can retract or extend in 0.2 seconds so we retrict ourself to max. of 4 to 6 bar pressure operation.

As cycle is to be completed in 8 seconds, 4 bar pressure is sufficient.

We designed Mitre bevel gear from Design data book taking cylinder specs into account.

From gear pair , Shaft was designed. Bearing selection was done then

Column was checked for buckling analysis. Swivel motion arc bracket was made.

Cantilever beam analysis for carriage ,then Mountings plus sliding chuck was designed.

Strong foundation design and guideways for vertical cylinder were provided at last.

Design of assembly in CATIA

Part drawing was done in CATIA V5 and then assembly was done.

Material was applied appropriately and CG ,weight ,MI were calculated then.

Drafting was done for mfg drawings to workshops.

Material selection :

1. Cast IronIt has good damping property and less density than steel but costly and not readilyavailable. Density= 7250 kg/m^3.

2. Mild SteelIt has compartively less damping but good welding characteristics and cheap plus

readily available. Density= 7850 kg/m^3

3. AluminiumLight weight with hardness and stiffness. Easy riveting possible.

Density = 2710 kg/m^3

4. NylonFor easy sliding of carriage , nylon or teflon was considered.

Ansys analysis

Critical components like horizontal shaft, arc bracket , base plate were examined for static and dynamic failure.

Fos was safe for design made.

Pneumatic circuit concept

1. Push button operated2. Interlocking circuit using limit switch operation3. Electro-pneumatic circuit using relays,reeds and solenoids.4. Micro- controller based.5. PLC based.

Pneumatic circuit working

Automation Studio 5.0

Pure pneumatic circuit was made in this software but electro pneumatic circuit was just developed but not simulated.

Fluidsim and autosim (SMC) softwares were tried out.

Electro-pneumatic circuit :The sensing time of reed switch is 1 millisecond.Reeds operate at 24 V DC

Solenoid valves operate at 24 V DC with 104 mA current.

As relay logic and logic gates could not be built , we choose controller.

So A micro controller 8052 was used taking sensors as inputs (8) and solenoids as output (8) . Reset function was provided in case of sudden stops.

C programming successfully implemented the required logic on controller.

Gripper

1. Mechanical 2 finger gripper

2. Vaccum gripper

2 finger gripper had to be imported hence made a compact gripper from small double acting cylinder having one fixed jaw and other movable.

Habonim 4 piston actuator :

Robot Specifications

1.Payload : ½ kg2. Weight : 22.4 kg3. Cost : 51,200 uptil now4. Control method : Micro controller5. Material : Mild steel for foundation, Aluminium for manipulator6. Configuration : Semi- cylindrical (swing arm)7. DOFs : 4 (3 cylinder + 1 gripper)8. Actuator : Mitre bevel gear rotation using swing cylinder9. Kick stroke : Linear nylon guide rail.10. Vertical stroke : Gripper with guide way 11.M/c tonnage : 30 to 55 tons12. Power supply : 24 V DC ,1 A 13. Air consumption :14. Swing angle : 50 to 90 deg both sides.15 .Max pressure: 6 bar16. Working pressure: 2 to 4 bar17. Overall cycle time : within 8 secs.

BOM 1 out of 4 billsSr. no Model no. Specification /product Qty Cost Total

1 A52020080O DA 20 x 80 Cyl.(Mag) Basic 1 1243 1243

2 A52025080O DA 25 x 50 Cyl.(Mag) Basic 1 1323 1323

3 A52016160O DA 16 x 160 Cyl.(Mag) Basic 1 1176 1176

4 DS254SS60-W 1/8 -5/2,24V DC Double Sol. valve 4 2030 8120

5 GR5105006 Flow control valve 1/8 x Dia 6 6 224 1344

6 WP2210650 Male elbow Dia 6 x 1/8 8 43 344

7 MS022 DOUBLE FOOT MOUNTING (DIA 20,DIA 25) 1 234 234

8 AA022 CLEVIS FOOT BRACKET (DIA 20,DIA 25) 1 148 148

9 AP010 ROD END SPHERICAL EYE (DIA 25,DIA 32) 2 560 1120

10 AP008 ROD END SPHERICAL EYE (DIA 20) 1 511 511

11 AM1016 Reed switch with clamp (A52016) 2 451 902

12 AM1020 Reed switch with clamp (A52020) 2 451 902

13 AM1025 Reed switch with clamp (A52025) 2 451 902

14 FRCLM146234/W FRCLM-3/8(40Micron,10bar)with Wall mounting brack 1 2649 2649

15 WP2110851 Male connector Dia8x 1/4 2 36 72

16 M0030104 Manifold (4 Valves) DS2-1/8,5/2,5/3 1 1355 1355

17 ASC0161 Silencer (Conical-1/4) 2 83 166

18 WP2110852 Male connector Dia8x3/8 1 41 41

19 A2G02 Pressure gauge(0-10bar)R1/8,Dia 40 1 171 171

20 WH00B08 TUBE(PU) OD8 (Blue) 2 56 112

21 WH00B06 TUBE(PU) OD6 (Blue) 8 31 248

22 Parallel Gripper (10/ 16 dia) 1 0

23 Reed switch for parallel gripper 2 0

24 WC1 Tube cutter 1 135 135

Total 23218

Motion sequence of Pneumobot:

1. vertical arm descend Cylinder A+2. strip forward Cylinder B+3. grip on / vaccum on Gripper C+4. strip backward Cylinder B-5. vertical arm retract Cylinder A-6. swing outward Cylinder D+7. grip off /vaccum off Gripper C-8. swing inward Cylinder D-

We implemented the logic A+B+C+B-A-D+C-D- using relay(4 three pin & 4 five pin relay) along with 4 double solenoid valve and 8 reed switches(magnetic sensor).

Above sequence can be changed as required using micro-controller or PLC.

For interfacing with IMM , micro-controller or PLC is needed.

1. Milling2. Boring3. Tapping4. Welding 5. Grinding6. Drilling7. Turning and Facing8. Laser cutting9. Hack saw cutting10.Rivetting11.Surface finishing12.Grub holes

Fabrication operation

Material was purchased from Bhosari.

Manufacturing was done at Talwade,Akurdi

Final mfg and finishing was done at Nangergoan ,Lonavla

Final Assembly

All components were joint and made ready.

Piping was done properly along with sensor wiring connection through insulation casing.

Manifold and controller housing was done. Gauge and frc unit was interfaced then.

Thank You