APPARATUS FOR CONTINGENCY CONTROLLING ENGINE
ROTATIONAL SPEED OF HEAVY CONSTRUCTION EQUIPMENT
Technical Field
The present invention relates to an apparatus for controlling an engine
rotational speed, and more particularly, to an apparatus for contingency controlling an
engine rotational speed of a heavy construction equipment capable of contingency
controlling the speed of an engine when a controller of the heavy construction
equipment such as an excavator does not operate normally.
Background Art
In general, a known engine rotational speed controlling apparatus used to
control an engine rotational speed of a heavy construction equipment such as an
excavator is shown in FIG. 1.
According to the known engine rotational speed controlling apparatus, an
operator controls a control dial 1 manually in order to control a rotational speed of an
engine 4.
The control dial 1 is electrically connected with an equipment control
unit(MCU) 2 and an engine control unit(ECU) 3 therein to transfer a value controlled by
the operator to the engine 4.
In this case, the known machine control unit 2 wholly controls various driving
devices required to drive the construction equipment and the engine control unit 3
controls driving of the engine among various driving devices of the construction
equipment. Further, the control dial 1 converts a value inputted by the operator into a
voltage value and transfers the converted voltage value to the machine control unit 2.
Accordingly, in the known engine rotational speed controlling apparatus,
when the operator controls the control dial 1, the machine control unit 2 gives a

command to the engine control unit 3 by receiving the corresponding voltage value and
controls the engine rotational speed as high as a value controlling the control dial 1 to
drive the engine 4.
However, in the known engine rotational speed controlling apparatus, when
the control dial 1 or the machine control unit 2 are defective, an operation for the engine
rotational speed cannot be normally controlled, and as a result, there is inconvenience in
that the operator cannot control until the operator changes the control dial 1 or the
machine control unit 2.
Disclosure
Technical Problem
The present invention is contrived to solve the problems and an object of the
present invention is to provide an apparatus for contingency controlling an engine
rotational speed of a heavy construction equipment capable of contingency controlling
the speed of an engine when a controller such as a machine control unit or a dial does
not operate normally in the heavy construction equipment.
Technical Solution
In order to achieve the object, an apparatus for contingency controlling an
engine rotational speed of a heavy construction equipment according to the present
invention including a control dial for controlling a rotational speed of an engine and a
machine control unit generating a driving signal to control an operation of the engine by
transferring a control value received from the control dial to an engine control unit
includes: an instrument panel electrically connected with the engine control unit and
allowing an operator to select and control a desired engine rotational speed because a
control algorithm for the engine rotational speed is made into a database; and a
connection switch electrically connecting the instrument panel and the engine control

unit when the control dial or the machine control unit does not operate normally.
According to the exemplary embodiment of the present invention, the
instrument panel may include: a storage previously storing the control algorithm for the
engine rotational speed; an input controller allowing the operator to select and control
the desired engine rotational speed; and a controller reading a value corresponding to a
predetermined control signal from the storage when receiving the predetermined control
signal through the input controller, and outputting the read value to the engine control
unit.
According to the exemplary embodiment of the present invention, the engine
control unit may control the engine rotational speed through the control dial and the
instrument panel in a normal state and in addition, control the engine rotational speed
through a control signal finally controlled between the control dial and the instrument
panel and control the engine rotational speed only in the instrument panel when the
connection switch is abnormally controlled.
According to the exemplary embodiment of the present invention, the
connection switch may automatically connect the instrument panel and the engine
control unit when any one of the machine control unit and the dial is erroneous.
According to the exemplary embodiment of the present invention, the
connection switch may be additionally provided in the instrument panel or an operating
room to be switched by operator's selection.
According to another exemplary embodiment of the present invention, the
instrument panel may be additionally connected even to the machine control unit, the
connection switch may be installed between the machine control unit and the engine
control unit and disconnect the machine control unit and the engine control unit from
each other and connect only the instrument panel and the engine control unit to each

other when the machine control unit and the dial are erroneous, and the engine control
unit may be driven based on a signal received from the machine control unit when the
engine control unit is connected to both the machine control unit and the instrument
panel and driven based on a signal received from the instrument panel when the engine
control unit is connected with only the instrument panel.
In this case, the connection switch may automatically connect the instrument
panel and the engine control unit when any one of the machine control unit and the dial
is erroneous.
According to another exemplary embodiment of the present invention, the
connection switch may be additionally provided in the instrument panel or an operating
room to be switched by operator's selection.
Advantageous Effects
As described above, according to the present invention, when a controller of a
heavy construction equipment does not operate normally, an operator can contingency
operate an engine by using an electronic instrument panel, and as a result, stability of
the heavy construction equipment can be ensured.
Description of Drawings
FIG. 1 is a configuration diagram showing a known engine rotational speed
controlling apparatus of a heavy construction equipment.
FIG. 2 is a configuration diagram showing an apparatus for contingency
controlling an engine rotational speed of a heavy construction equipment according to
an exemplary embodiment of the present invention.
FIG. 3 is an example of an instrument panel shown in FIG. 2.
FIG. 4 is a graph for describing a control algorithm of an engine rotational
speed of a heavy construction equipment according to an exemplary embodiment of the

present invention.
FIG. 5 is a configuration diagram showing an apparatus for contingency
controlling an engine rotational speed of a heavy construction equipment according to
another exemplary embodiment of the present invention.
FIG. 6 is a configuration diagram showing an apparatus for contingency
controlling an engine rotational speed of a heavy construction equipment according to
yet another exemplary embodiment of the present invention.
FIG. 7 is a configuration diagram showing an apparatus for contingency
controlling an engine rotational speed of a heavy construction equipment according to
still yet another exemplary embodiment of the present invention.
Best Mode
Hereinafter, an apparatus for contingency controlling an engine rotational
speed of a heavy construction equipment according to an exemplary embodiment of the
present invention will be described in detail with reference to the accompanying
drawings.
FIG. 2 is a configuration diagram showing an apparatus for contingency
controlling an engine rotational speed of a heavy construction equipment according to
an exemplary embodiment of the present invention, FIG. 3 is an example of an
instrument panel shown in FIG. 2, and FIG. 4 is a graph for describing a control
algorithm of an engine rotational speed of a heavy construction equipment according to
an exemplary embodiment of the present invention.
The engine rotational speed controlling apparatus of the heavy construction
equipment described in the exemplary embodiment has a basic configuration in which a
machine control unit receives a value inputted from an external control dial to control
the engine rotational speed.

As a result, the engine rotations speed controlling apparatus of the heavy
construction equipment according to the exemplary embodiment of the present
invention may be configured to include a control dial 10 which can be manually
controlled by an operator, a machine control unit(MCU) 20, an engine control
unit(ECU) 30, an instrument panel 40, a connection switch 50, and an engine 60, as
shown in FIG. 2.
The control dial 10 is additionally provided in an operating room of the heavy
construction equipment so as for the operator to control a desired engine rotational
speed. The control dial 10 may be provided in a rotary lever type as shown in the
figure and may set the corresponding engine rotational speed to 1000 rpm, 1500 rpm,
2000 rpm, 2500 rpm, and the like according to a rotational angle. The set values are
converted into voltage values and applied to the machine control unit 20.
In this case, the engine rotational speed which can be set through the control
dial 10 may increase and decrease by a predetermined unit. For example, the
rotational engine speed may increase or decrease from 1000 rpm to 1500 rpm by the
unit of 500 rpm and the set unit may be variously modified and changed by the unit of
the minimum 1 rpm.
The machine control unit 20 controls all various controllers that control
various driving devices for driving the heavy construction equipment.
In particular, the machine control unit 20 according to the exemplary
embodiment of the present invention receives the value set through the control dial 10
and transfers the received value to the engine control unit 30. In this case, the value
received from the control dial 10 becomes as the voltage value acquired by converting
the value set through the control dial 10. Accordingly, the corresponding engine
control unit 30 is controlled in order to drive the engine 60 with the voltage value.

The engine control unit 30 generates a driving control signal for driving the
engine 60 on the basis of a set value received from the machine control unit 20 or
instrument panel 40.
The connection switch 50 serves to electrically connect the instrument panel
40 and the engine control unit 30 to each other according to a switching operation when
the control dial 10 or the machine control unit 20 does not operate normally. The
connection switch 50 may operate by a selection control of the operator and can be
configured to operate when the machine control unit 20 and the control dial 10 are
erroneous. In the former case, the connection switch 50 is provided in the instrument
panel 40 in a button type or additionally provided in the operating room to operate
according to selection or not of the operator as shown in FIG. 3. In the latter case, the
connection switch 50 requires an additional component capable of detecting errors of
the machine control unit 20 and the control dial 10.
The instrument panel 40 according to the exemplary embodiment of the
present invention is provided outside the heavy construction equipment like the control
dial 10 to provide an interface capable of operating the engine rotational speed normally.
The instrument panel 40 is electrically connected with the engine control unit
30 according to the operation of the connection switch 50 as shown in FIG. 2 and a
control algorithm for the engine rotational speed is made into a database to enable the
operator to select and control the desired engine rotational speed.
Specifically, the instrument panel 40 may include an input controller 41 with
control buttons (41a and 41b of FIG. 3) that allow the operator to select and control the
desired engine rotational speed, a storage 44 previously storing the control algorithm for
the engine rotational speed, a controller 42 that reads an engine rotational speed value
corresponding to a predetermined control signal from the storage 44 and outputs the

read value when the predetermined control signal is inputted through the input
controller 41, and a display 43 visually displaying the engine rotational speed value
which the operator sets through the input controller 41, a presently set engine rotational
speed value, and the like.
Herein, the control algorithm for the engine rotational speed is constructed
based on a linear graph shown in FIG. 4.
The linear graph shows the engine rotational speed value with parts. In this
linear graph, the minimum and maximum engine rotational speeds A and B which can
be controlled in operating the engine exist and stepwise engine rotational speed values
A1 to A7 classified by the unit of a predetermined fraction within a range between the
minimum and maximum engine rotational speeds A and B are previously set.
Accordingly, when the operator controls the engine rotational speed through the input
control unit 41, there is used an algorithm scheme to mach the stepwise engine
rotational speed values A1 to A7 corresponding to the corresponding control values.
For example, it is assumed that the controllable engine rotational speed is in
the range of 500 rpm to 1500 rpm. Therefore, the minimum engine rotational speed A
is 500 rpm and the maximum engine rotational speed B is 1500 rpm. When the range
therebetween matches 0 to 100% and the fraction is set to 10%, an algorithm in which
the following values Al, A2, A3, ... of the minimum engine rotational speed A are 600
rpm, 700 rpm, 800 rpm, (omitted) ,1300 rpm, 1400 rpm may be applied.
Accordingly, when the operator controls the engine rotational speed by using
the input controller 41 with the up/down buttons 41a and 41b shown in FIG 3, the
controller 42 reads an engine rotational speed value increased or decreased by a
predetermined fraction from the storage 44 every time the operator controls the up and
buttons 41a and 41b once and outputs the read value. The outputted engine rotational

speed value is transferred directly to the engine control unit 30 to normally control the
driving of the engine.
An operating method of the apparatus for contingency controlling the engine
rotational speed according to the exemplary embodiment of the present invention
configured as above will be described below.
The operator controls the engine rotational speed by using the control dial 10
in normal times and when the controller of the heavy construction equipment, such as
the control dial 10 or the machine control unit 20 does not operate normally, the
operator operates the connection switch 50 to electrically connect the instrument panel
40 and the engine control unit 30 to each other.
The control algorithm for the engine rotational speed is previously
constructed in the instrument panel 40. Therefore, when the operator controls the
engine rotational speed through the input controller 41, the instrument panel 40 outputs
the corresponding engine rotational speed value every time the operator operates the
control buttons of the input controller 41 once on the basis of the algorithm.
In this case, the outputted engine rotational speed value is applied to the
electrically connected engine control unit 30, and as a result, the engine 60 can be
normally controlled by using the instrument panel 40 in contingency.
Meanwhile, the present invention is not particularly limited to the above-
mentioned exemplary embodiment. For example, as shown in FIGS. 5 and 6, the
instrument panel 40 may be configured to be connected to the machine control unit 20
and the engine control unit 30 in parallel. In this case, the connection switch 50 may
be configured in various types.
Specifically, referring to FIG. 5, the connection switch 50 is installed between
the machine control unit 20 and the engine control unit 30 to serve to disconnect the

machine control unit 20 and the engine control unit 30 when the machine control unit 20
is erroneous. In this case, the engine control unit 30 can receive control signals from
both the machine control unit 20 and the instrument panel 40 and when receiving the
signals from both components, the engine control unit 30 is preferably configured to
preferentially react to the machine control unit 20.
Further, the machine control unit 20 receives the signals from both the
instrument panel 40 and the control dial 10 and although the operator controls any one
of the instrument panel 40 and the control dial 10, a signal corresponding thereto can be
outputted to the engine control unit 30. In this case, the machine control unit 20 and
the engine control unit 30 are controlled to be operated with the controlling device
which the operator prefers between the control dial 10 and the instrument panel 40 in a
normal state and the engine control unit 30 may be configured to be controlled based on
the signal inputted from the device operated most recently.
On the contrary, in a contingency case, the engine rotational speed should be
controlled to be adjusted in only the instrument panel 40. Moreover, the machine
control unit 20 further includes a function to warn an error through the instrument panel
40 in the contingency and more preferably inform the operator of controlling the engine
rotational speed through only the instrument panel 40.
FIG. 6 shows another exemplary embodiment of the present invention and is
different from the exemplary embodiment of FIG. 5 in that the signal of the instrument
panel 40 is inputted into only the engine control unit 30. In this case, since the
machine control unit 20 may not judge which signal between the signals inputted from
the control dial 10 and the instrument panel 40 is preferential, a load of the machine
control unit 20 may be reduced. Meanwhile, the engine control unit 30 should perform
the same function as that of the above-mentioned exemplary embodiment.

FIG. 7 shows yet another exemplary embodiment of the present invention and
unlike the above exemplary embodiments, the signal outputted from the instrument
panel 40 is outputted to the machine control unit 20 or the engine control unit 30 by
using the connection switch 50. In this case, the connection switch 50 is preferably
configured to be switched by automatic or manual operation like the above exemplary
embodiments. Accordingly, it can be expected the effect that the loads of the machine
control unit 20 and the engine control unit 30 can be reduced as compared with those of
the above exemplary embodiments.
Although the exemplary embodiments of the present invention have been
described with reference to the accompanying drawings, it will be understood to those
skilled in the art that the present invention can be implemented in other detailed forms
without changing the spirit or essential features.
Accordingly, since the above-mentioned exemplary embodiments are
provided to inform those skilled in the art of the scope of the present invention, it should
be understood that they are exemplary in all aspects and not limited and the present
invention is just defined by the scope of the appended claims.
Industrial Applicability
The present invention can be applied to a system for controlling an engine
rotational speed of a heavy construction equipment in contingency.

CLAIMS
1. An apparatus for contingency controlling an engine rotational speed of a
heavy construction equipment including a control dial for controlling a rotational speed
of an engine and a machine control unit generating a driving signal to control an
operation of the engine by transferring a control value received from the control dial to
an engine control unit, the apparatus comprising:
an instrument panel electrically connected with the engine control unit and
allowing an operator to select and control a desired engine rotational speed because a
control algorithm for the engine rotational speed is made into a database; and
a connection switch electrically connecting the instrument panel and the
engine control unit when the control dial or the machine control unit does not operate
normally.
2. The apparatus for contingency controlling an engine rotational speed of a
heavy construction equipment according to claim 1, wherein the instrument panel
includes,
a storage previously storing the control algorithm for the engine rotational
speed;
an input controller allowing the operator to select and control the desired
engine rotational speed; and
a controller reading a value corresponding to a predetermined control signal
from the storage when receiving the predetermined control signal through the input
controller, and outputting the read value to the engine control unit.
3. The apparatus for contingency controlling an engine rotational speed of a
heavy construction equipment according to claim 1 or 2, wherein the engine control unit
controls the engine rotational speed through the control dial and the instrument panel in

a normal state and in addition, controls the engine rotational speed through a control
signal finally controlled between the control dial and the instrument panel and controls
the engine rotational speed only in the instrument panel when the connection switch is
abnormally controlled.
4. The apparatus for contingency controlling an engine rotational speed of a
heavy construction equipment according to claim 1 or 2, wherein the connection switch
automatically connects the instrument panel and the engine control unit when any one
of the machine control unit and the control dial is erroneous.
5. The apparatus for contingency controlling an engine rotational speed of a
heavy construction equipment according to claim 1 or 2, wherein the connection switch
is additionally provided in the instrument panel or an operating room to be switched by
operator's selection.
6. The apparatus for contingency controlling an engine rotational speed of a
heavy construction equipment according to claim 1 or 2, wherein:
the instrument panel is additionally connected even to the machine control
unit,
the connection switch is installed between the machine control unit and the
engine control unit and disconnects the machine control unit and the engine control unit
from each other and connects only the instrument panel and the engine control unit to
each other when the machine control unit and the control dial are erroneous, and
the engine control unit is driven based on a signal received from the machine
control unit when the engine control unit is connected to both the machine control unit
and the instrument panel and driven based on a signal received from the instrument
panel when the engine control unit is connected with only the instrument panel.
7. The apparatus for contingency controlling an engine rotational speed of a

heavy construction equipment according to claim 6, wherein: the connection switch
automatically connects the instrument panel and the engine control unit when any one
of the machine control unit and the control dial is judged to be erroneous.
8. The apparatus for contingency controlling an engine rotational speed of a
heavy construction equipment according to claim 6, wherein: the connection switch is
additionally provided in the instrument panel or the operating room to be switched by
operator's selection.

The present invention relates to an apparatus for contingency controlling an
engine rotational speed of a heavy construction equipment, which is capable of
contingency controlling the speed of an engine when a controller of the heavy
construction equipment such as an excavator does not operate normally. The
apparatus for contingency controlling an engine rotational speed including a machine
control unit generating a driving signal to control an operation of the engine by
transferring a control value received from a control dial to an engine control unit may
include: an instrument panel electrically connected with the engine control unit and
allowing an operator to select and control a desired engine rotational speed because a
control algorithm for the engine rotational speed is made into a database; and a
connection switch electrically connecting the instrument panel and the engine control
unit when the control dial or the machine control unit does not operate normally.