Using The Robot Safely; Robot Safety Functions - Yamaha YK250XGC Installation Manual

6.

Using the robot safely

6.1

Robot safety functions

Safety functions for YAMAHA robots are described below.
1. Overload detection
This function detects an overload applied to the motor and shuts off the servo power.
If an overload error occurs, take the following measures to avoid such errors:
1. Insert a timer in the program.
2. Reduce the acceleration coefficient.
2. Overheat detection
This function detects an abnormal temperature rise in the driver inside the controller and shuts off the servo power.
If an overheat error occurs, take the following measures to avoid the error:
1. Insert a timer in the program.
2. Reduce the acceleration coefficient.
3. Soft limits
Soft limits can be set on each axis to limit the working envelope in manual operation after return-to-origin and during
automatic operation. The working envelope is the area limited by soft limits.
soft limits must be set within the movement range (mechanical stoPPer). if the soft limit is set outsiDe
ThE MOvEMEnT RangE, ThEn ThE RObOT axIS May COllIDE WITh ThE MEChanICal STOPPER aT hIgh SPEED,
CaUSIng ThE ObjECT gRIPPED by ThE EnD EffECTOR TO fly OUTWaRD OR DROP, anD ThE RObOT TO
MalfUnCTIOn.
4. Mechanical stoppers
If the servo power is shut off by emergency stop operation or safety function while the robot is moving, then these
mechanical stoppers prevent the axis from exceeding the movement range. No mechanical stopper is provided on the
rotational axis. The movement range is the area limited by the mechanical stoppers.
• The X and Y axes have mechanical stoppers that are installed at both ends of the maximum movement range. Some
robot models have a standard feature that allows changing the mechanical stopper positions. On some other models,
the mechanical stopper positions can also be changed by using option parts.
• The Z-axis has a mechanical stopper at the upper end and lower end. The stopper positions can be changed by using
option parts.
• No mechanical stopper is provided on the R-axis.
axIS MOvEMEnT DOES nOT STOP IMMEDIaTEly afTER ThE SERvO POWER SUPPly IS ShUT Off by EMERgEnCy STOP
OR OThER SafETy fUnCTIOnS.
5. Z-axis (vertical axis) brake
An electromagnetic brake is installed on the Z-axis to prevent the Z-axis from sliding downward when servo power is
OFF. This brake is working when the controller is OFF or the Z-axis servo power is OFF even when the controller is ON.
The Z-axis brake can be released by the programming unit / handy terminal or by a command in the program when the
controller is ON.
ThE vERTICal axIS WIll SlIDE DOWnWaRD WhEn ThE z-axIS bRakE IS RElEaSED, CREaTIng a hazaRDOUS
SITUaTIOn.
• Press the emergency stoP button anD Place a suPPort unDer the vertical axis before releasing the
bRakE.
• be careful not to let your boDy get caught between the vertical axis anD installation base when
RElEaSIng ThE bRakE TO PERfORM DIRECT TEaCh.。
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