US 4,635,439 AGranted

Fluid operated system control

AssigneeCaterpillar Industrial Inc.

InventorJohn E. Wible

Life of this patent

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Abstract

A control having a primary work system, a secondary work system, a first fluid flow generating system, and a second fluid flow generating system is provided. A control signal delivering device is provided to deliver a control signal having a magnitude responsive to a relative location of a control valve between a first and second position of a control valve. A control signal receiving device receives the control signal and separately controls the flow rate deliverable from the first and second flow generating system in response to the magnitude of the control signal received. The control signal receiving device has a set point value which is representative of a preselected magnitude of the received control signal. The second fluid flow generating system is controlled to deliver fluid only in response to the magnitude of the received control signal having a value greater than preselected deliverable flow rate. The first flow generating system is controlled to deliver fluid at a rate responsive to the magnitude of the received control signal and, during periods at which the received control signal has a value greater than the set point, reduces the fluid flow deliverability rate of the first flow generating system, an amount substantially equal to the flow rate being delivered by the second flow generating system.

Claims11

Dependent claims

A control for a work vehicle, comprising:

a fluid operated steering system having a fluid operated steering motor and a steering control valve connected to said steering motor;
a fluid operated implement system having a fluid operated implement motor and an implement control valve connected to said implement motor, said implement control valve having first and second positions and being movable between said positions;
a flow control valve connected to said steering control valve and said implement control valve;
a first pump having a preselected maximum flow delivering capacity and being connected to said flow control valve;
a first variable speed motor drivingly connected to said first pump, said flow control valve being adapted to deliver fluid flow from said first pump to said steering control valve and said implement control valve on a steering flow priority demand basis;
a second pump having a preselected maximum flow delivering capacity and being connected to said implement control valve, said maximum flow delivering capacity of the first pump being greater in magnitude than said maximum flow delivering capacity of the second pump;
a second single speed motor drivingly connected to said second pump, said second pump being adapted to deliver fluid flow to said implement control valve and in bypass of said steering system;
means for delivering a control signal having a magnitude representative of the relative position of the implement control valve between said first and second positions;
and
means for receiving said control signal and increasing the speed of the first motor from a minimum speed towards a maximum speed in response to movement of said implement control valve from said first position toward said second position, simultaneously actuating the second motor and decreasing the speed of the first motor in response to said implement control valve being at a preselected location between said first and second positions, and increasing the speed of said first motor in response to movement of said implement control valve from said preselected location toward said second position.

7 more elements

A work vehicle, comprising:

a vehicle frame;
a work implement mounted on said frame;
a steering system having a fluid operated steering motor and a steering control valve connected to said steering motor;
an implement system having a fluid operated implement motor and an implement control valve connected to said implement motor, said implement control valve having first and second positions and being movable between said positions;
a flow control valve connected to said steering control valve and said implement control valve;
a first pump connected to said flow control valve;
a first variable speed electric motor drivingly connected to said first pump, said first being adapted to deliver fluid flow at a rate proportional to the speed of the first electric motor, said first pump having a preselected maximum flow rate limit;
said flow control valve being adapted to pass fluid flow delivered from the first pump to said steering control valve and said implement control valve on a steering flow priority demand basis;
a second pump connected to said implement control valve;
a second single speed electric motor drivingly connected to said second pump, said second pump being adapted to deliver fluid flow to said implement control valve at a preselected flow rate, said preselected flow rate of the second pump being smaller in magnitude than the maximum flow rate of the first pump;
means for delivering a variable control signal having a value representative of each location of the implement control valve between said first and second positions;
and
means for receiving said control signal and simultaneously decreasing the speed of said first variable speed motor and actuating said second single speed motor in response to said control signal being at a preselected value.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/722,236Filed 11 Apr 1985
Granted: 13 Jan 1987
Term ends: Not estimatedThe source records don’t support an estimate.

Classification21 codes

B62D 5/07
Fluid, i.e. using a pressurised fluid for most or all the force required for steering a vehicle: supply of pressurised fluid for steering also…
B66F 9/22
Means for actuating or controlling masts, platforms, or forks: hydraulic devices or systems
F15B 11/17
With two or more servomotors: using two or more pumps
F15B 21/087
Servomotor systems incorporating electrically operated control means: control strategy, e.g. with block diagram