AZ Automotive Weld Tooling & Assembly Equipment Standards Revision 1.6      16Sep2004

PRINTED COPIES ARE UNCONTROLLED

Deviations that improve safety, quality, or cost ARE ALWAYS WELCOME.


SECTION 7

7.     Robots

7.1.            Design

 

7.1.1.                                             

It shall be the design Supplier's responsibility to develop the location of the robots and the robot's associated equipment. The subject locations shall be determined by the robot's work assignment and the end effector (s) used in the application. Strong considerations shall be given to the efficiency of the robot and its associated equipment in its specified operation, as well as service ability and safety.

 

7.1.2.                                             

All robot interfaces approved by AZ Automotive.

 

7.1.3.                                             

The robot shall be shown in the following positions:

A. Pounce

B. Work

C. Fully extended

D. Fully retracted

E. Maximum height

 

7.1.4.                                             

The product shall be shown at its work position and at its transfer position, when applicable.

 

7.1.5.                                             

The end effector shall be shown in its intended location on the robot's gear train with its tool center point referenced from the dowel hole on the robot's mounting face.

 

7.1.6.                                             

The design of the robot and its end effector must be within AZ Automotive electrical, mechanical, and pneumatic standards.

 

7.1.7.                                             

It shall be the design supplier's responsibility to obtain approval of loading and center of gravity of all robot end effectors. Approval will require completion of a "Robot Loading Analysis Sheet" supplied by the robot manufacture and submitting the completed form along with a matrix indicating total project end effector usage to the robot manufacture for approval. The design supplier is required to retain copies of the approved form for review by AZ Automotive.

 

7.1.8.                                             

Each sealing robot shall include a setting (calibration) gauge.

 

7.1.9.                                             

All material handling robot gripper designs must be of a single point of contact on the part. All contact shall be on flat surfaces. One jaw of the gripper shall remain stationary. Panel size and weight will be the deciding factor.

 

7.1.10.                                          

On welding applications, the welding transformer and accessory package shall be dimensionally located in the workstation and the intended path of all cables and hoses shall be shown.

 

 

 

 

7.1.11.                                          

Robot weld studies must include the following:

A. Mainline and back up weld sequence

B. Mainline, back-up, and tip-dress cycle times

C. Weld schedules

 

 

7.2.            Robot Control Program

 

7.2.1.                                             

The integrator shall provide (2) sets of the robot programs to AZ Automotive prior to line shipment. The storage devices shall be clearly marked and must contain all robot system definition or parameters.

 

7.2.2.                                             

The robot's program must be developed to insure that the end effector does not pull, bend, twist, or drag on the product or any related equipment.

 

7.2.3.                                             

The mainline and back-up process (if required) shall be done in the most efficient manner relating to robot movement.

 

7.2.4.                                             

Mainline and tip-dress cycle time shall be within the system cycle time.

 

7.2.4.1

All robot tip dress programs shall be robot controlled.

 

7.2.5.                                             

All robot programs and related storage blocks not related to the process must be eliminated from the robot's memory before the 20-hour run.

 

7.2.6.                                             

Robot programs shall follow AZ Standard programming.
See AZ PLC Standards for details.

 

7.2.7.                                             

The PLC shall consist of the logic necessary to automatically or manually control the entire robot cell. It shall be structured to easily interface with the other areas of the entire system and follow AZ Automotive PLC robot logic standards. Sample logic is available from AZ Automotive.

 

7.2.8.                                             

The PLC program shall control individual robot activity. Sample interface logic can be obtained from AZ Automotive.

 

7.2.9.                                             

The PLC program shall keep track of styles as the part moves through the system. This style information shall be used to instruct the robot to execute various cycles dependent on style or back-up requirements. The robot program numbers shall follow the set design, which is available from AZ Automotive.

 

7.2.10.                                          

The controller shall provide for multiple robot program selection. This shall conform to the robot's back-up requirement plus (2) programs.

 

7.2.11.                                          

Provide diagnostics, which will alert personnel to problems with robots and workstation automation.

 

7.2.12.                                          

If required by process, putting any individual robot in "Bypass," will cause other robots to execute the "Bypassed" robots weld task. Back-up responsibilities for any robot will be received through manipulation of the style information sent to the robot(s). AZ Automotive Tool Process Engineering will develop the back-up responsibilities for all robots on specific systems.

 

 

7.3.            Identification

 

7.3.1.                                             

All robots shall be assigned a robot number designation. (ref: FIS Identification)

 

7.3.2.                                             

The Supplier shall stencil identification on the following items:

A.      Robot control panels - the call out R##, R##, etc., in 4" high letters on front of the robot control cabinet. (ref: FIS Identification)

B.       Robot arm - The call out R##, R##, etc. in 4" high letters on the robot arm. (ref: FIS Identification)

 

7.3.3.                                             

The robot supplier will provide limit switches and adjustable actuators as follows:

(1)    Arm back limit switch with adjustable actuator. (Arm Back Limit)

(1)    Base limit switch with an adjustable actuator. (Base Limit #1)

(3)    Base limit switches and separately adjustable actuators will be provided with material handling robots. (Base Limits #1, #2, and #3)

(3) Base limit switches and separately adjustable actuators will be provided with robots utilizing tool changers. (Base Limits #1, #2, and #3)

(3) Base limit switches and separately adjustable actuators will be provided with dual process robots. (Dual process defined but not limited to multiple end effectors and/or working stations and/or functions. i.e. dual pedestal welders, sealer and welder, material handling and welder). (Base Limits #1, #2, and #3)

 

Robot limit switches will be defined as follows:

 

Arm Back Limit

 

"ARM BACK"

This limit switch is located on the arm or elbow of the robot with an adjustable actuator. The "Arm Back" limit switch is installed on all robots. This switch is to be monitored by the PLC. The signal will be high when the robot is clear of all tooling motion. The signal shall remain high when the robot is in the programmed "Home Position". The switch and actuator will be supplied by the robot manufacturer and shall be adjusted and wired by the Tooling Supplier. (Ref: "Project" Robot WD)

 

Base Limit #1

 

"AT TIP DRESS/SERVICE POSITION"

This limit switch is located on the base axis of the robot (axis #1) and monitors the position of the arm in relation to the stationary base of the robot. The "Base Limit #1 is installed on all robots. The signal from this limit switch will be high when the robot is at its programmed "TIP DRESS" position. The "TIP DRESS" position should be clear of the fixture(s), transfer and any movable tooling dumps, etc.

 

"AUXILIARY CLEAR"

This limit switch may also be used for robot clear (i.e. material handling, sealer) of line/fixture/dumps when clear of pick-up and drop-off (ref. Base limits #2 & #3) are not adequate for this function.

 

Base Limit #2

 

"CLEAR OF PICK-UP"

This limit switch is located on the base axis of the robot (axis #1) and monitors the position of the arm in relation to the stationary base of the robot. The "Base Limit #2 is installed on all Material Handling Robots. The signal from this limit switch will be high when the robot is at its programmed "CLEAR OF PICK-UP" position.

 

"CLEAR OF FIXTURE #1"

Simflex Robots

 

"CLEAR OF GUN/TOOLING CRADLES"

Stud welding / Tool Changing Robots

 

Base Limit #3

 

"CLEAR OF DROP-OFF"

This limit switch is located on the base axis of the robot (axis #1) and monitors the position of the arm in relation to the stationary base of the robot. The "Base Limit #3 is installed on all Material Handling Robots. The signal from this limit switch will be high when the robot is at its programmed "CLEAR OF DROP-OFF" position.

 

"CLEAR OF FIXTURE #2"

Simflex Robots

 

Clear Limit #4

 

"ROBOT END OF ARM TOOLING CLEAR"

This switch may be used for robot clear of line/fixture when the Arm Back Limit switch is not adequate for this function. (I.e. weld gun, end effector).  AZ Automotive will define the use and location of this switch. The Integrator shall provide and install this switch, regardless of who purchases the robot.  This limit switch is wired directly back to a PLC input.

 

"ROBOT CLEAR OF CONVEYOR"

This switch may be used to indicate to the conveyor that the robot is clear of the conveyor and/or carriers with or without parts on them. The Integrator shall provide and install this switch, regardless of who purchases the robot.  This limit switch is wired directly back to the tooling PIP and is interlocked with the conveyor PLC. The signal is powered, monitored and controlled by the conveyor PLC.

 

Note: All documentation shall include the base limit switch number and identification.

 

7.3.4.                                             

All robots on multi-station systems shall be identified with an alphanumeric identification. Following line flow, all robots on the left hand side of the line will be odd numbered, and all robots on the right hand side of the line will be even numbered. Robots located in the center of the line or system will be named according to the direction of its work envelope. (i.e. a robot located in the center of the process but its work envelope is on the right side of the line will be numbered accordingly. Future installation of robots should be considered by reserving numbers for these robots.

 

For Mirrored Transfer Systems (Right/Left Hand):

Right hand part system:

 

. Left hand side of the line in direction of line flow, robots will have Odd numbers.

. Right hand side of the line in direction of line flow, robots will have Even numbers.

. Future installation of robots should be considered during naming procedure by reserving numbers for   these robots.

 

Left hand part system:

 

                    . Left hand part robot names will mirror the right hand part robot names.

 

Exceptions to this procedure will be addressed by a AZ Automotive representative. The format for identifying robots and equipment is available from a AZ Automotive Controls Coordinator.

 

 

7.4.            Construction/Installation

 

7.4.1.                                             

Provide a separate circuit breaker for each robot controller.

 

7.4.2.                                             

The integrator shall install, start-up, try-out, and program all robots used in the system. The programs shall conform to the AZ Automotive supplied robot programming standards. Modifications to the program structure must be approved by AZ Automotive.

 

7.4.3.                                             

A buy-off is required at the final installation site. This buy-off will consist of operation, safety programming and cycle time. The guidelines established and implemented at integrators facility will be used.

 

7.4.4.                                             

All robots must be properly phased as part of their installation start-up assistance.

 

7.4.5.                                             

After installation at the unit plant all robot programs shall be "touched-up" as required to insure that each robot performs within it's allotted cycle time

 

7.4.6.                                             

The Integrator shall provide and install all limit switches and hard-stops required to meet AZ Automotive and O.S.H.A. standards.

 

7.4.7.                                             

The "Arm Back" limit switch should not be actuated during the robot work program.

 

7.4.8.                                             

The Tooling Supplier shall provide and install all limit switches required to maintain an end of arm tooling clear signal when at home position if the end of arm tooling can be rotated into tooling motion while the robot "Arm Back" signal is high. (Ref: 7.3.4 "Clear Limit #4)

 

7.4.9.                                             

When manual back-up capabilities are used in the process, the Tooling Supplier shall provide and install all limit switches required to indicate when the robot is in a stored position. (Ref: 7.3.4 Clear Limit #4) This position shall be clear of any back-up personnel and/or equipment required to perform manual or automatic back-up procedures. This monitored position shall be clear of any tooling or conveyor motion.

 

 

7.4.10.                                          

In applications where manual part loading is processed in the robots work envelope, the Tooling Supplier shall provide and install, on the robot arm, pull plugs with chain that limit the robots reach. The pull plug shall be wired directly to the robots emergency stop circuit. The pull plug and chain shall be designed and installed in a manner that assures the robot and end effector cannot contact the operator.

 

7.4.11.                                          

On all robot-welding applications, the power distribution between weld controllers and welding transformers shall include:

A.      A 200 amp fuse-able disconnect switch for close-couple weld guns except where weld control circuit breaker is sized at 250 AMPS.

B.       B. Terminal boxes on all cable-type weld guns when weld controllers are remote mounted.

 

7.4.12.                                          

Robot controlled pedestal weld guns utilizing a weld stroke valve and retract valve shall incorporate a device that would electrically indicate, to the robot, that the weld gun is in the fully retracted (retract returned) position.  Cylindicators can be used only with AZ Automotive approval.

 

7.4.13.                                          

Provide guarding around robot cells. The total length of system shall be guarded by a fence or screen type barrier. Safety gates and fencing shall conform to NAAMS North American Automotive Metric Standards (formerly ACRGS). Use non-adjustable perimeter fence posts. (Refer to Website: http://www.a-sp.org)

A. Provide safety gates with electrically interlocked plugs for access to robot work stations. Each safety plug shall be wired back to the power panel in its area.

B. Improper entry to the robot workstation shall cause a "Cycle Stop" condition. Proper entry can be accomplished by putting the appropriate robot in hold.

C. Special guarding around robots may be required for material handling applications. Corporate Safety will direct any special guarding.

 

7.4.14.                                          

Robot pinch point safety distance between robot work envelope and any obstacle shall be a minimum of 18 inches.

 

7.4.15.                                          

The system and its robots shall be in accordance with O.S.H.A. and A.N.S.I./R.I.A. R15.06 standards on robot safety.

 

7.4.16.                                          

Robot installations shall be provided with safety circuitry to hold the program count, while de-energizing robot actuator drive power.

 

7.4.17.                                          

The integrator shall supply any platforms (risers) required to elevate robots into an acceptable work height.

 

7.4.18.                                          

The integrator shall assemble in their facility, by special means, if necessary, the complete setup for each robot. These setups shall include all of the equipment necessary to complete a functional tryout.

 

7.4.19.                                          

The integrator shall provide a barrier to protect the transfer rails from a robot malfunction.

 

7.4.20.                                          

All robot-related PLC's will contain "Robot Slow Cycle" timers and alarms for each station.

 

7.4.21.                                          

The integrator shall provide manual back-up capability for all automatic load/unload stations. This shall include all safety related items required to manually back-up the robots assignment.

 

7.4.22.                                          

The integrator shall supply and install all robot-welding accessories to include all components, brackets, etc. This includes all robot dress accessories.

 

7.4.23.                                          

The integrator shall provide approved robot grounding.

 

7.4.24.                                          

The integrator shall make provisions to connect to approved robot-grounding networks for the systems to be provided by others.

 

7.4.25.                                          

All robot cables and hoses shall be of sufficient length and shall be mounted in such a manner as to provide a minimum of wear throughout all robot motions.

 

7.4.26.                                          

Install all cables entering robot cabinet in such a manner as not to create a strain on the connector end.

 

7.4.27.                                          

All material handling robots must be ready to load parts at the beginning of the next cycle and within system cycle rate limits.

 

7.4.28.                                          

Overhead structures must have proper clearances so that the robot can be moved to its alignment positions without removing the end effector.

 

7.4.29.                                          

The integrator shall determine the location and set all electrical, mechanical, and software limit stops.

 

7.4.30.                                          

The integrator shall provide laminated I/O plates mounted on each robot controller showing

A.      I/O assignments

B.       I/O numbers

C.       I/O designations.

 

7.4.31.                                          

The integrator shall provide a list of all hardware and software jumpers used for the 20 Hour Run.

 

7.4.32.                                          

All 20 Hour Run jumpers must be removed at the completion of the 20 Hour run and prior to system buy-off.

 

7.4.33.                                          

The integrator will be financially responsible for all assistance from the robot supplier other than warranty related items, regardless of who purchases the robots.

 

 

7.4.34.                                          

The integrator shall provide the following in each robot controller cabinet along with two (2) additional copies for AZ Automotive:

 

A. Program printouts with TCP and software values indicated.

B. Robot and remote I/O cross-references on interfacing.

C. Robot cycle time and weld schedule verification chart.

D. Weld Study (if applicable).

 

7.4.35.                                          

The integrator shall repackage and ship all robots in the same manner as they were shipped from the robot supplier and with the end effector, hoses, and electrical wiring also remaining on the robot.

 

7.4.36.                                          

Robot installation. (See Illustration 7-2-0) The illustration depicts the following;


A. Mounting pedestal (in 7-2-0) shown only for illustration, not necessarily required.

B. Leveling plates with tapping plates (in 7-2-0 also)

The leveling plates are 12" square, 1" thick, with three mounting holes as shown. The 1" thick tapping plates are approximately 4" by 4", or the size required to facilitate the mounting of the robot. The tapping plate is usually welded to the leveling plate after positioning of the robot.

 

7.4.37.                                          

Supplier shall provide a pneumatic lockable type ball valve, with a safety exhaust feature, for service air to each tip dresser and robot.

 

 

7.5.            Automatic Tip Dress

 

7.5.1.                                             

Automatic Tip Dresser considerations WHEN REQUIRED ON THE PURCHASE ORDER:

 

7.5.2.                                             

The Supplier shall locate, supply, and install for each resistance welding robot (1) AZ Automotive approved automatic tip dresser and calibration gauge.

A. Location of tip dresser shall be approved by AZ Automotive, and shown in each robot station drawing.

B. The Supplier shall provide for each pneumatic and/or electric tip dresser: power, controls, logic, interface, tryout, etc.

C. Controls shall energize tip dresser prior to electrode contact.

D. The calibration gauge shall be designed as a swing in unit.

E. Pneumatic systems shall be four horsepower or greater.

 

7.5.3.                                             

Verify that the proper tip-dress cutters are used for each specific operation.

 

7.5.4.                                             

Automatic tip dresser shall include but not be limited to the following:

 

1. Capability of dressing both electrodes at the same time in (2) seconds.

2. Capability of dressing electrodes with a tip force of 300 lbs. or greater.

3. Capability of dressing RWMA Class II, dispersion strengthened copper (Glid-Cop) & zirconium copper electrode material.

4. Latest cutter technology to optimize cutter life.

5. Capability of dressing electrodes with a minimum of 1" point opening.

6. Cutters must be capable of dressing any combination of:

A. 1/2", 5/8" or 3/4" diameter electrodes.

B. A, B, C, E, F and special nose configurations.

C. Tip angles from 0 to 45 degrees to centerline of cutter.

7. Provisions to accept and retain cutter holder assembly.

8. Float mount for tool.

9. Multi-plane mounting (X, Y, Z axis).

10. Heavy duty adjustable stand (floor, ceiling, wall mountable).

11. Air blow off for chip removal.

12. Large sturdy funnel guide to insure proper alignment of tips to cutter.

13. AZ Automotive approved 24 VDC solenoid and manual shut-off valve.

14. Capability of working at 80 P.S.I. line pressure (if air motor).

15. AZ Automotive approved filter and lubricator (if air motor).

16. AZ Automotive approved fused disconnect with motor starter in a NEMA 12 enclosure (if electric motor).

17. Electric motor shall be: 3 phase, 460 volts, 60 hertz.

 

7.5.5.                                             

ELECTRODE DESIGNATION

 

Nose Size                                                                               AZ Automotive Standard

nose configuration

 

4 - 1/2" dia. electrode nose                                                 A - pointed nose

5 - 5/8" dia. electrode nose                                                 B - dome nose

6 - 3/4" dia. electrode nose                                                 C - flat nose

D - offset nose

E - truncated nose

F - radius face

S - special

 

0 to 45 degrees - angle to centerline of cutter.

 

Example

 

 

 

7.6.            Robotic End-Of-Arm-Tooling Guidelines

 

7.6.0.                                             

All end-of-arm tooling must use two (2) dowels.

 

7.6.1.                                             

All designs shall incorporate ease of maintenance and repair.

 

7.6.2.                                             

All standard purchased components shall be chosen from the AZ Automotive Approved Source list.

 

7.6.3.                                             

Fatigue calculations and durability certification shall be provided for all components.

 

7.6.4.                                             

Torque specifications shall be supplied with each tool and also listed in the EOAT service manual.

 

7.6.5.                                             

FMEA’S on all manufactured components shall be supplied at concept approval stage, and provided on all as-built documents, as well as in the service manual.

 

7.6.6.                                             

All suppliers shall use standard machining practices as per the Machinery Handbook.

 

7.6.7.                                             

All designs shall include AutoCAD drawings.

 

7.6.8.                                             

Construction shall be bolted, except with prior, written engineering consent.

 

7.6.9.                                             

Paint-dot and safety wire all torqued, bolted connections, after torque verification. (Use bright fluorescent orange paint.)

 

7.6.10.                                          

Design concept and detail layout shall contain provisions for efficient deployment of cables and / or hoses.

 

7.6.11.                                          

Air lines shall be a minimum of 1/4 inch unless otherwise specified.

 

7.6.12.                                          

Facility air supply operating pressure will be assumed to be 80 psi..

 

7.6.13.                                          

Where applicable, robotic EOAT should be protected from damage through the use of a mechanical or pneumatic breakaway device, mounted between the robot tool mounting flange and the EOAT.

 

7.6.14.                                          

Where feasible, aluminum modular components should be considered for EOAT design and construction, in place of steel.

 

7.6.15.                                          

Fail-safe designs shall be utilized in clamping and holding operations to guarantee safe operation, and minimize part and equipment damage.

 

7.6.16.                                          

In applications where weight requirements dictate the use of steel rather than aluminum components, or where any type of welding is utilized in the construction process, such welds shall be tested for weld and component integrity, with the minimum test being Magna fluxing. Test results shall be included in the EOAT service manual.

 

7.6.17.                                          

Both Supplier and installation contractor shall be licensed and inspected regularly to insure conformance to standard steel and aluminum welding practices.

 

7.6.18.                                          

If any type of welding is used in the construction of the EOAT, the supplier of the tool shall be registered with a recognized welding association. (Documentation shall be provided with the EOAT service manual).

 

7.6.19.                                          

Stencil total weight on all end effectors.