KE-750_MAINTE.pdf - 第47页

2.2 Explanation on Z/ θ axes [LAHD head] [LAIC head] Z motor (30 W) encoder, 1000 ppr θ motor pulley θ motor pulley θ pulley θ pulley θ motor (30 W) encoder, 2000 ppr Ball screw (10 mm lead) θ encoder, 18000 ppr Z motor …

2. EXPLANATION ON XY, Z, AND θ AXES

2.1 Explanation on X/Y axes

Motor pulley M

Pulley XA

X (Y) belt Pulley XB

X motor (600 W)

Y motor (800 W)

• Deceleration ratio of motor pulley M to pulley XA: 36:120

• Ratio of diameter of the pitch circle of pulley XA: 28.65:114.59

The amount of movement of XY axes per motor rotation is:

36/120 × 28.65 × π = 27 mm

Therefore:

Resolution of motor encoder is 4096 (ppr) × 4 (multiplied) = 16,384 (ppr)

It is 27 mm/16,384 = 1.6479 µm/pulse

Resolution of linear scale is:

40 µm × 4 (multiplied) = 10 µm/pulse

Detection of open circuit of the external encoder

Every time the motor encoder rotates by 1/4 turn or every time the command

pulses equal to or more than 1/4 turn of the external encoder are input, an

alarm may occur if the difference between the rotation of the motor and the

rotation of the external encoder plus remaining pulses becomes 1/8 rotation of

the motor encoder or more.

A comparison and computation is carried out for 27/4 = 6.75 mm = 675 pulses

±675/2 pulses (1/8 rotation) at every 4096 pulses of 1/4 rotation.

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2.2 Explanation on Z/θ axes

[LAHD head] [LAIC head]

Z motor (30 W)

encoder, 1000 ppr

θ motor pulley

θ pulley

θ motor (30 W)

encoder, 2000 ppr

Ball screw

(10 mm lead)

θ encoder,

18000 ppr

Z motor (30 W)

encoder, 1000 ppr

Ball screw

(10 mm lead)

θ motor (30 W)

encoder, 2000 ppr

NOTE: Z and θ axes of the LA head are the same as that of the LAHD.

(1) Resolution of θ axis

When the laser recognition is installed for the LAHD, LA head, and LAIC

head

θ axis deceleration ratio: 2.25

θ motor encoder:

2000 pulses/round (8000 pulses/round when multiplied by 4)

Therefore: Resolution is 360/8000 × 2.25 = 0.02 deg/pulse

When the vision recognition is installed for LAIC head

θ axis direct couple encoder:

18000 pulses/round (72000 pulses/round when multiplied by 4)

Therefore: Resolution is 360/72000 = 0.005 deg/pulse

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3. SEQUENCE OF FUNCTIONS

3.1 Origin Return Operation

An origin return operation is carried out by pressing the ORIGIN key. The

origin return for Z axis, θ axis, and XY axes are sequentially performed.

3.1.1 Z axis

Origin return for Z axis

Alarm?

Origin deceleration sensor OK?

Move until the origin deceleration

sensor turns off.

Move until the origin deceleration

sensor turns on.

Move away from the origin deceleration

sensor.

Move by 1 step until the origin

deceleration sensor turns on.

Move by 1 step until the index pulse is

detected.

Initialization of work data

Considered to be normal Considered to be faulty

End

YES

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