Blastrac BMS-270LPII, Руководство по эксплуатации

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Revision B
Revised 5/20/2003 12:33 PM
49
Operating Instructions BMS-270LPII
Hydraulic System
10.5 Control Valve Assembly
Item 5 (P002433) on Service Drawing 700-SD0010 is a 2-spool control valve assembly with
a 1500 psi internal relief valve. One section of the valve is controlled by an electric solenoid
while the other section is control by a mechanical control handle. The rocker switch on the
blade control joystick operates the electric solenoid. If the rocker switch is pushed on the
left, the valve shifts and allows fluid to flow into the piston end of the cylinder causing the
rod to extend and the blade to lower. Conversely, if the rocker switch is pushed to the right,
the valve shifts and allows fluid to flow into the rod end of the cylinder causing the rod to
retract and the blade to lift. The 2-spool valve is an open center valve. In its de-energized
state, i.e. there are
not control movements and the mechanical control handle is in the center
position, it allows fluid to simply pass through the valve and back to the hydraulic tank.
Since the relief valve is set at 1500 psi, that is the maximum pressure the valve will supply to
the cylinders or auxiliary tools. The cylinders will never need more than 500 psi to 800 psi
of pressure to operate properly depending on the operator and multiscraper weight. If a tool
requires more than 1500 psi to operate, the relief valve can be adjusted to a maximum of
2400 psi. If the relief valve is set above 2400 psi, the resulting torque at full flow rate will
severely damage the pump. Please contact a Blastrac Specialist before attempting to adjust
the relief valve setting. An incorrect setting could cause damage to the hydraulic
components.
If you have purchased or wish to purchase optional tools for your BMS-270LPII you will
need to contact Blastrac Customer Service for details 1-800-256-3440. These tools will be
available by the end of 2003. Availability is subject to change; please call Blastrac for
optional tool inquiries.
The other section of the 2-spool valve controls the auxiliary tools. If you have the capability
to add optional tools you will notice a mechanical handle in the 2-spool valve. This handle
Shifts the spool that meters fluid into the optional tools. If the handle is in the center
position, no fluid is sent to the tool. If you move the handle up, the tool will rotate in a
clockwise fashion. The amount of handle movement determines the amount of fluid flow to
the tool, thus determining the speed of the tool. Conversely, if you move the handle down
the tool will rotate in a counter-clockwise fashion. Again, the amount of handle movement
determines the amount of fluid flow to the tool, thus determining the speed of the tool.
WARNING: Always have the motion control joystick in the center position
before starting the BMS-270LPII. If the motion control joystick is not in the
center, the tool will turn when the multiscraper is started, possibly injuring the
operator or other personnel and damaging the tool or pump.