Vestil LLH-202053-FWFL handleiding
Handleiding
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Table of Contents Rev. 8/15/2023 LLPH MANUAL
Table of Contents Copyright 2020 Vestil Manufacturing Co. Page 27 of 29
HYDRAULIC SYSTEM OPERATION (REFER TO CIRCUIT DIAGRAM ON P. 26)
Raising the deck: The sequence begins with the foot pedal in the neutral, or “home”, position. The
operator first activates the hydraulic system by pressing the foot pedal down. This is referred to as a
“power-stroke”. After releasing the foot pedal, the piston return spring (B) exerts an upward force on
the piston. Consequently, oil flows from the reservoir, through the inlet check valve, and into chamber
A. At the same time, oil trapped in chamber B (from a prior cycle) flows across the back-fill check into
chamber A. When another power stroke occurs, the inlet check valve closes, which prevents oil from
flowing back into the reservoir; simultaneously, the outlet check valve opens and oil flows into the
cylinder. In preparation for the next stroke, the piston return spring forces the piston and the foot pedal
back to the home position. Chamber A again fills with oil as the piston rises.
The pump piston has two modes of operation: 1) Low-pressure, high-volume; and 2) High-pressure,
low-volume.
1. Low-pressure, High-volume.
When raising an unloaded or lightly loaded platform, the piston will function in low-pressure mode. As
the operator presses the foot pedal (power stroke):
a. Back-fill check remains closed;
b. High / low volume relief poppet remains closed; and
c. All oil in chamber A flows into the cylinder.
2. High-pressure, low-volume
When raising a partly loaded or heavily loaded platform, the piston will function in high-pressure mode.
As the operator executes a power stroke, the back-check remains closed:
a. High / low volume relief poppet opens;
b. A volume of oil equal to the annulus (piston diameter minus the rod diameter) flows from A to B;
c. Oil equal to the cross-sectional area of the rod flows to the cylinder; and
d. The opening force of the high / low volume relief poppet adds to the cylinder load resistance.
Pressure relief system
If a load that exceeds the maximum rated load is placed on the deck, or a mechanical malfunction
interferes with the movement of the deck, the pressure relief valve will open during a power-stroke. The
pressure relief valve reduces the likelihood that excessive loads will damage the lifter frame or the
hydraulic system. The pressure relief valve directs oil from chamber A to the reservoir.
Release valve assembly
The foot-actuated release valve assembly is the mechanism that allows the deck to lower. When the
release pedal is pressed down, the release valve opens, and oil flows from the cylinder to the reservoir.
The lowering rate is adjustable; instructions appear under RELEASE PEDAL ADJUSTMENT on p. 22.
Lowering rate is also variable: the farther down the release pedal is pressed, the more rapidly the deck
descends. The weight of a load on the deck affects the flow rate, and therefore, a heavier load will
lower more rapidly than a lighter load, regardless of the lowering rate selected. When the operator lets
the pedal loose, the release pedal tensioning spring returns the release pedal to the home position,
which automatically closes the valve.
Bekijk gratis de handleiding van Vestil LLH-202053-FWFL, stel vragen en lees de antwoorden op veelvoorkomende problemen, of gebruik onze assistent om sneller informatie in de handleiding te vinden of uitleg te krijgen over specifieke functies.
Productinformatie
| Merk | Vestil |
| Model | LLH-202053-FWFL |
| Categorie | Niet gecategoriseerd |
| Taal | Nederlands |
| Grootte | 11991 MB |
