METHOD AND DEVICE FOR REGULATION OF A COOLING FAN DRIVE ON AN INTERNAL COMBUSTION ENGINE IN A CONSTRUCTION OR WORKING MACHINE

PROCEDE ET DISPOSITIF DE REGLAGE D'UN ENTRAINEMENT DE VENTILATEUR SUR UN MOTEUR A COMBUSTION INTERNE DANS DES MACHINES-OUTILS ET/OU MACHINES DE CONSTRUCTION

English Abstract

The invention relates to a method for regulation of a cooling fan drive on an
internal combustion engine, in particular equipped with several independent
cooling circuits, in a construction or working machine, whereby the power
drain of the cooling fan drive is set to approximately zero during certain
working stages of the construction and/or working and said power drain may be
added to the capacity for the working stage.

French Abstract

L'invention concerne un procédé de réglage d'un entraînement de ventilateur sur un moteur à combustion interne, équipé en particulier de plusieurs circuits de refroidissement indépendants, dans des machines-outils et/ou machines de construction. Selon ce procédé, la consommation de l'entraînement de ventilateur est réglée à environ zéro à certains cycles de travail prédéfinis de la machine-outil et/ou machine de construction et cette consommation est ajoutée à la capacité relative au cycle de travail.

Claims

Claims
1. A process for regulating the fan motor (4) of internal combustion engines
(1) in construction
and/or work machines, particularly those with several independent cooling
circuits (2 and 3),
where the power of fan motor (4) is set to null for certain operations
performed by
construction and/or work machines and this power is used to perform these
operations.
2. A process in accordance with claim 1, characterized in that cooling circuit
(2 and 3) is set to
at least two different desired temperature values, whereby for certain
operations performed
by construction or work machines, one desired temperature is set to a higher
desired
temperature by means of a switch (19) and a change-over switch (15) and the
power of the
fan motor (4) is set to null.
3. A process in accordance with claim 1 or 2, characterized in that when there
are several
cooling circuits (2 and 3) present, each cooling circuit (2 and 3) is set to
at least two
different desired temperatures by means of a common setting device (10).
4. A process in accordance with claims 1 to 3, characterized in that the
desired and actual
temperatures are compared by one µ-controller-P1-regulator (13 and 14) per
cooling circuit
(2 and 3) and the permissible setting for each cooling circuit (2 and 3) is
determined.
5. A process in accordance with claims 1 to 4, characterized in that a
comparator (16) operating
with P1-controller(s) (13 and 14) determines a maximum setting from the
individual
setting(s) and passes this on to a pulse width modulation stage (17)
operationally connected
to a setting device (10).
6. A process in accordance with claims 1 to 5, characterized in that, for
certain construction
and/or work machine operations, particularly raising the boom (6) of a
hydraulic excavator,
the desired temperatures of all the cooling circuits (2 and 3) are essentially
raised at the same
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time, whereby the power of fan motor (4), particularly when fan wheel (5) is
idling, is set to
null and the driving power of fan motor (4) is transferred to the operation of
the construction
and/or work machine, particularly the lifting capacity of boom (6), thus
increasing this
capacity.
7. A device for regulating the fan motor (4) of internal combustion engines
(1) in construction
and work machines, particularly those with several independent cooling
circuits (2 and 3),
with at least one change-over switch (15), at least one P1-controller (13 and
14) per cooling
circuit (2 and 3), at least one post-installed comparator (16) and at least
one pulse width
modulator (17) operationally connected to a setting device (10).
8. A device in accordance with claim (7), characterized in that the regulator
(13 and 14) is a
µ-controller-P1-regulator.
6

Description

CA 02426452 2003-04-24
Method And Device For Regulation Of A Cooling Fan Drive On An
Internal Combustion Engine In A Construction Or Working Machine
This invention concerns a process for regulating the fan motor of internal
combustion engines in
construction or work machines, particularly those with several independent
cooling circuits.
In DE-A 195 35 674, a process is proposed for regulating the cooling system of
excavators,
particularly those with powerful diesel engines, where a thermostat located in
the area of the
diesel engine opens the flow from the diesel engine to a water cooler with an
integrated fan at a
predetermined temperature, so that a temperature measuring device installed in
the area of the
flow controls the fan in such a way that, within a given temperature range
above the
thermostat-regulated water temperature, the rotation speed of the fan is set
in the range between
Omiri' and a maximum rotation speed.
In DE-A 198 25 759, a hydraulic drive subassembly, including a variable
displacement pump,
which is connected in a closed circuit with a motor to drive an auxiliary
device such as a fan, is
described. An auxiliary pump can be functionally connected with the pump, the
engine and a
container so that losses of the fluid in the closed circuit are replenished.
An auxiliary circuit,
which is connected to the pump, has a bypass that is connected with the closed
circuit upstream
of the motor in order to reduce the required volume of the container.
Construction or work machines, particularly hydraulic excavators, are designed
for certain
maximum performances that consist of, for example, performing repetitive
operations such as
raising the boom and moving the upper chassis relative to the lower chassis.
The internal combustion engines in these construction and work machines,
particularly
hydraulic excavators, are normally water-cooled and have an adjustable fan
which is turned on
and off in response to rises in the temperature in the cooling circuit of the
engine by a separate
hydraulic motor usually controlled from the engine.

CA 02426452 2003-04-24
During the normal operation of construction or work machines, particularly
hydraulic
excavators, the fans are usually turned on when a predetermined temperature is
exceeded in the
engine's cooling circuit. 'The operating fan requires a certain amount of
power to regulate the
temperature of the cooling circuit.
Then, not all the motor's power is available, for example to raise a boom,
because of the loss of
power to the operating fan, and, in certain marginal ranges, this can result
in the power of the
engine being insufficient to perform the work.
This purpose of this invention is to provide a process and a device for
regulating fan motors in
which the operations performed by construction or work machines can be
increased a manner
that improves performance without causing a loss of power in the area of the
engine.
This goal is achieved through a procedure for regulating fan motors on engines
in construction
and/or work machines, particularly those that have several independent cooling
circuits, where
the power of the fan motor is set to zero during certain operations performed
by the construction
and/or work machine and the power is used to perfonm these operations.
Beneficial extensions of the invention can be inferred from the associated
process-related
subclaims.
This goal is also achieved through a device for regulating the fan motor of
intenxal combustion
engines in construction and/or work machines, particularly those with several
independent
cooling circuits, with at least one Pl-regulator per cooling circuit, at least
one post-installed
comparator and at least one pulse width modulator operating with a setting
device.
In another version of the invention, the regulator is a p-controller-Pl-
regulator.
The subject of the invention makes it possible to set to at least two
different desired
temperatures of a fan motor in several independently operating cooling
circuits of an internal
combustion engine by means of a common setting device, where the power of the
fan motor
2

CA 02426452 2003-04-24
while performing certain operations is zero (the fan idles) and the fan power
can then be used to
perform these operations.
With one p,-controller-Pl-regulator per cooling circuit, the desired and
actual values are
compared and the required setting for each cooling circuit is determined. The
post-installed
comparator determines the maximum setting from the individual settings and
sends this to a
PWM (pulse width modulation) stage, which is connected to the setting device.
When particular
operations are performed, for example raising the boom of a hydraulic
excavator, the desired
temperatures of the cooling circuits are essentially raised at the same time.
Thus, the power of
the fan motor is set to zero (the fan idles) and the lifting power increases
by the amount required
to run the fan.
Depending on the size of the construction or work machine, particularly in the
case of large
hydraulic excavators, lifting power when raising a boom can be increased
without causing
overheating of the drive unit. This is because the fan motor power is not
needed all the time, but
only during predetermined operations of the construction or work machines.
The sole figure shows a basic sketch and is described as follows:
There is an internal combustion engine (1) which, in this example, has two
independent cooling
circuits (2 and 3), that are connected by means of a controller (9) to a
setting device (10) on an
adjustable fan motor (4) with a fan wheel (5). There is also a device (6), for
example the boom
of a hydraulic excavator, which is not shown, which is mounted on an upper
chassis (7), which
is only outlined, and can be raised and lowered by means of hydraulic cylinder
(8). Hydraulic
circuit (11), which is used to raise and lower device (6), hydraulic circuit
(12) for fan motor (4)
and hydraulic circuit (20), which is needed to feed setting device (10), are
shown. Each cooling
circuit (2 and 3) has a p-controller-Pl-regulator that compares the desired
and actual values and
calculates the appropriate setting for each cooling circuit (2 and 3). The
desired values are
provided to the p-controller-Pl-regulators ( 13 and 14) by a change-over
switch ( 15). The values
provided by the p,-controller-Pl-regulators ( 13 and 14) are fed to a post-
installed comparator

CA 02426452 2003-04-24
( 16), which determines the maximum setting from the individual settings and
passes it on to a
PWM (pulse width modulation) step 17, which is connected to setting device
(10) by means of
wire ( 18). Part of the power of engine ( 1 ) is used to operate device (6),
while another part of the
power is required for fan wheel (5) to protect engine ( 1 ) from overheating.
For certain
operations, for example raising device (6) using hydraulic cylinder (8), it
can happen that engine
( 1 ) is not quite able to raise device (6).
With this invention, for such operations, the desired temperatures of cooling
circuits (2 and 3)
are raised to higher temperatures by means of a switch ( 19) and a change-over
switch ( 15).
Thus, the power of fan motor (4) is set to zero by means of wire (18) and
setting device (10).
Fan wheel (S) slows down or idles. The hydraulic power of fan motor (4), which
is now no
longer needed to power fan wheel (5), is thus added to the lifting power of
device 6 without
causing engine (1) to overheat. As soon as the certain operation is completed,
hydraulic fan
motor (4) is again connected to fan wheel (S), thus the higher desired
temperature for each of
cooling circuits (2 and 3) is again assigned a lower desired temperature by
means of switch (19)
and change-over switch (15). This process can be repeated in any sequence,
which ultimately
depends on the maximum performance assigned to specific operations.
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Representative Drawing