Adjustment mode

D - 4 Valve Adjustment

The characteristics of actuator operation speed necessary for the slow stop to AML valve control output (D/A command value) are stored as the valve output adjustment value.

[NOTICE]

Slow stop function corresponding to the proportional solenoid valve does not work until the valve adjustment is completed.

The subjected crane operations are described below.

- Swing (right, left) operation

- Elevation (raising, lowering) operation

- Boom telescoping (retracting) operation

4.1 Adjustment Sub Menu

When "Valve Adjustment" is selected in the adjustment main menu of Fig. 1.3.3, the selection screen for subjected adjustment work is displayed as shown in Fig. 4.1.1 Press the < > key (backward) or the < > key (forward) to highlight the selected adjustment item. To go back to the adjustment main menu, press the < > key.

The mark " " is shown at the left of the item that is already adjusted.

4.2 Slewing Output Adjustment (Characteristics Measurement Method)

The offset method keeps only the stop points in memory, so it may fail to decelerate the crane smoothly in some direction clockwise and counterclockwise. To achieve smooth deceleration, characteristics measurement method is used for adjustment of the outputs.

With the crane set in the specified configuration for measurement (the crane is set level on extended outriggers; the engine speed is maximum; the slewing lever is shifted to the full stroke), the degree of change of the slewing speed according to the current output to the proportional solenoid valves is measured. Not only stop points of the slewing table but the starting point of deceleration and the data during deceleration are measured and kept in memory. The characteristics measurement method smoothly decelerates and stops boom slewing on the basis of these measured characteristics.

In the valve adj. item selection screen shown in Fig. 4.1.1, select "Swing right" or "Swing left," then press the < > key to display the slewing output adjustment display of Fig. 4.2.1.

4.2.1 Adjustment Procedure

With the screen of Fig. 4.2.1 displayed, press the < > key to change the display to the screen shown in Fig. 4.2.2.

- After setting the posture to the specified one, set the engine speed to the maximum, and then perform a full lever operation to start the measurement. [NOTICE]

Remember that the measurement will be started as soon as the lever is operated, even if the crane condition differs from the specified crane condition.

When the measurement is started unexpectedly, leave the lever at the neutral position to terminate the measurement. Subsequently, start the process again from the status indicated in Fig. 4.2.1.

When the measurement is started, the slewing speed is gradually increased. After the maximum slewing speed is reached, the speed is decelerated with specified time intervals. When "Slew velocity" in the screen of Fig. 4.2.3 becomes zero, the measurement is completed. Then, the screen changes to the one shown in Fig. 4.2 .4.

With the screen of Fig. 4.2.4 displayed, setting the lever to the neutral position automatically changes the screen to Fig. 4.2.1, and the slewing output adjustment is completed.