Toyota 7BPUE15, Руководство по обслуживанию

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Toyota Orderpicker Model
15
Service Manual Section
9.
Theory of Operation
Lower
The lower button commands the carriage to
lower. When the lower button is pressed, the
proportional solenoid valve closes and
the load holding solenoid valve opens. The
proportional valve opens and allows hydraulic
fluid to return from the lift cylinders to the
reservoir.
When lower is no longer requested, the
proportional valve opens and the load holding
valve closes.
See Figure 9- 13 on page 9-44. (The electrical
schematic legend is on page 9-2.)
1. As the control handle lower switch is
closed, a digital ground is applied to
JPC 13-7 on the carriage manager.
2. The carriage manager sends a lower
command message to the
manager over the
lines.
Figure
9- 1 1.
on Controller
3. The manager provides the
negative potential for the
proportional valve coil a t
indicated by the load holding solenoid LED
on the manager. See
Figure 9- 1 1 on page 9-4 1. The
proportional valve ramps closed (this valve
is normally open).
4.
The manager provides the
negative potential for the load holding
valve coil a t indicated by the load
holding solenoid LED See
Figure 9- 1 1 on page 9-4 1. The coil
energizes and the load holding valve
opens.
5. The manager varies the
negative potential for the
proportional valve coil a t
indicated by the load holding solenoid
LED. The proportional valve
gradually opens allowing hydraulic fluid to
return to the reservoir. See Figure 9-12.
00700-CL222-05, 1 5
March
2005