JP2767125B2 - Fuel supply control system for special vehicle engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for controlling a fuel supply amount in an engine for a special vehicle such as a power shovel or a crane.

(Prior Art) As a conventional fuel supply control method and apparatus in a special vehicle engine, for example, Japanese Patent Publication No. 62-8620
There is a thing as shown in the gazette.

This is a control device of a system including an engine whose speed is controlled by adjusting a fuel supply amount, and a variable displacement hydraulic pump driven by the engine, and generates a target rotation speed signal of the engine. An operation device, comprising: an output rotation speed detection device for the engine; a calculation device that calculates a difference between the target rotation speed signal and the output rotation speed signal and generates a rotation speed deviation signal corresponding thereto; A first step of generating a fuel injection amount command signal that satisfies a predetermined functional relationship with the rotational speed deviation signal of the device;
And a device for adjusting the fuel injection amount in accordance with a command signal of the first function generating device. Based on the rotational speed deviation signal, a control pressure command signal satisfying a predetermined functional relationship therewith is generated. A control pressure is obtained from a command signal of the second function generator, and the control pressure is used to determine the maximum value of the input torque of the variable displacement hydraulic pump by the deviation of the rotational speed deviation. It is designed to decrease with increase.

Further, the target rotation speed set by the target rotation speed setting device and the actual rotation speed detected by the actual rotation speed detector are compared by a comparator. There is also known an engine controller for a construction machine which turns on either a speed-up relay or a deceleration lever of a control circuit to control the amount of fuel supplied to the engine (for example, see Japanese Utility Model Laid-Open No. 59-1846). ).

Further, Japanese Patent Application Laid-Open No. 63-235631 discloses that the engine output is controlled in accordance with a large output torque curve capable of obtaining a large output during a normal push-pull advance operation, and other than the normal push-pull advance operation. A description is given of a bulldozer engine output control method for controlling the engine output in accordance with an output torque curve suitable for each preset operation when performing the above operation.

(Problems to be Solved by the Invention) However, in the conventional fuel control device for an engine for a special vehicle described in Japanese Patent Publication No. 62-8620, an engine controlled by adjusting a fuel injection amount and an engine controlled by this engine In the system including the variable displacement hydraulic pump driven by the engine, even if the load increases, the engine is not stopped, and the engine output can be used to the maximum. It is stored in the control device corresponding to the specific type (capacity and type) of the driven variable displacement pump (working machine), and the maximum is obtained not only for the work by the working machine other than the variable displacement pump but also for the variable displacement pump. In order to make it possible to operate vehicles with different capacities under optimal conditions, measures to control the amount of fuel supplied to the relevant engine have been prepared. I didn't.

Further, in the conventional example described in Japanese Utility Model Application Laid-Open No. 59-1846, the amount of fuel supplied to the engine is increased or decreased by comparing the target rotation speed with the actual rotation speed detected by the detector, and the target rotation speed is increased. Although the target rotation speed can be changed and adjusted by operating the number setting device, the adjustment requires manual operation by the target rotation speed setting device. No measures were taken to drive under each optimal operating condition.

Furthermore, in the bulldozer engine output control method described in Japanese Patent Application Laid-Open No. 63-235631, although the engine output characteristics can be set freely according to the work of the bulldozer, the engine output can be effectively used without wasteful consumption. In addition, it is not assumed until this time that a work machine other than the work machine is attached to the engine to work.
Even if one of the first potentiometer for setting the fuel supply amount of the special vehicle engine and the throttle motor is replaced, the working efficiency of other equipment such as a working machine driven by the same special vehicle engine is used. There is no plan to make the process possible without impairing.

The present invention has been made in view of such a problem of the conventional example. Even when one of the first potentiometer for setting the fuel supply amount to the special vehicle engine and one of the throttle motor is replaced. In order to enable driving and processing without impairing the working efficiency of other equipment such as a working machine driven by the same special vehicle engine, the fuel supply amount of the special vehicle engine is controlled by the first potentiometer. The special vehicle engine uses a key switch from a microprocessor that previously stores a target rotation speed map that can be driven under optimum conditions even under different operating machines and / or under different operating conditions. The target rotation speed curve corresponding to the operation state by the machine or the working machine, and selecting the selected target rotation speed. Based on the curve, the rotation angle of the throttle motor corresponding to the working machine or the target rotation speed suitable for the operating state of the working machine is calculated by the microprocessor, and the slot value of the engine is calculated based on the output value of the microprocessor. A special vehicle in which a motor or a throttle lever driven by the throttle motor is driven so that a fuel supply amount to the engine can be controlled and set to an optimum value for the working machine or the operating state of the working machine. And a normal operation area corresponding to the working machine by the engine or the operating state by the working machine set by the first potentiometer. , The open area as an abnormal operation area outside the normal operation area A method for controlling the fuel supply amount in a special vehicle engine that operates more efficiently and safely than a conventional fuel supply control device for a special vehicle engine by allowing the lever to be set in advance using the lever of the first potentiometer. It is intended to provide a device.

(Means for Solving the Problems) In order to solve the problems in the conventional example described above, the present invention provides a first potentiometer for setting a fuel supply amount to a special vehicle engine, and a work driven by the engine. A microprocessor that previously stores a target rotation speed map corresponding to the type of machine and / or the operation state,
By a key switch of the microprocessor, a target rotation speed curve corresponding to the operation state of the working machine is selected from a target rotation speed map stored by the microprocessor, and the target rotation speed curve is selected based on the selected target rotation speed curve. A target rotation speed corresponding to the operation state of the work machine is calculated by the microprocessor, and the calculated target rotation speed is calculated from the microprocessor by a rotation angle of a throttle motor or a throttle lever driven by the motor. The fuel supply amount is output based on a rotation angle or a lever angle of a throttle motor that operates based on the output value, and the throttle motor position or a throttle lever position that is driven by the throttle motor. Are detected by the second potentiometer, and the A signal is fed back to the microprocessor, and the amount of fuel supplied to the special vehicle engine is set to a selected rotation speed curve of the target rotation speed map so that the operation state of the work machine is adjusted to a suitable operation state. A fuel supply amount control method for a special vehicle engine that controls a fuel supply amount to the engine so as to drive the work machine along the line.

A first potentiometer for setting a fuel supply amount to the special vehicle engine; a microprocessor for previously storing a target rotation speed map corresponding to a type of a working machine driven by the engine and / or the working state; From the target rotation speed map stored by the microprocessor,
A key switch for selecting a target rotation speed curve corresponding to the operation state of the work implement, and a target rotation speed corresponding to the operation state of the work implement based on the target rotation speed curve selected by the key switch. The microprocessor is operated by the microprocessor, and is driven based on an output value of the calculated target rotation speed from the microprocessor, and is driven by a throttle motor or a motor that controls a fuel supply amount to the engine. A throttle lever, a second potentiometer for detecting a position of the throttle motor or a position of a throttle lever driven by the throttle motor, and a microprocessor for detecting a signal of the throttle motor position or the throttle lever position by the second potentiometer. Feedback to A fuel supply amount control device in a special vehicle engine configured to automatically calculate and correct the fuel supply amount to the engine by the microprocessor so as to be suitable for the work state by the work machine, Further, the first potentiometer is an operating area normally corresponding to the type of the working machine driven by the engine and / or the working state of the working machine, and an upper and lower limit or the upper or lower limit of the normal operating area. A lever is provided which sets a region slightly upward or downward from the lower limit as a disconnection region as an abnormal operation region of the engine set by the first potentiometer.

(Operation) Since the present invention has the above-described configuration, the output of the first potentiometer for setting the fuel supply amount to the special vehicle engine is applied to the microprocessor of the engine, thereby providing the microprocessor with the engine. From a target rotation speed map composed of a plurality of target rotation speed curve groups stored in advance, the target rotation speed curve optimally corresponding to the working machine or the operation state of the working machine selected by the key switch of the microprocessor is obtained. On the basis of the microprocessor so as to optimally correspond to the working machine or the operating state of the working machine,
The throttle motor of the engine is driven to respond to the fuel supply amount set by the first potentiometer, or the throttle lever is driven via the throttle motor, and the throttle motor position or the throttle lever position is changed to the second position. A target rotation speed curve detected by a potentiometer, and a detection signal from the second potentiometer is also fed back to the microprocessor, set by the first potentiometer, and calculated by the microprocessor and optimal for the operation state of the working machine. Controlling the amount of fuel supplied to the engine for the special vehicle in accordance with the throttle motor angle or the throttle lever angle signal corresponding to the type of the working machine and / or the working condition so as to correspond to the optimum condition; and , The first The tension meter is configured such that the type of the working machine driven by the engine and / or the operating area normally corresponding to the working state of the working machine, and the upper and lower limits of the normal operating area or the upper and lower limits slightly. An area separated upward or downward can be set as a disconnection area as a non-operating area of the engine by the lever of the first potentiometer, so that the working machine or a normal fuel in a normal operating state by the working machine can be set. Whether it is within the supply area (whether it is a disconnection area)
Is automatically determined by the first potentiometer,
In the disconnection area, the fuel supply to the special vehicle engine is automatically shut off, thereby controlling the fuel supply amount to the engine so that the engine is driven at a rotation speed suitable for the type of the work machine and the operating state. In addition, the working machine in each operation state or a safe operation state in the operation state is ensured.

(Embodiment) An embodiment of a fuel control device for a special vehicle engine according to the present invention will be described below with reference to FIGS.

In the figure, 1 is a special vehicle engine, 2 is its governor, 3 is a disc-shaped throttle lever (fuel lever), 4 is a disc-shaped throttle lever 3 and a pulley 5 on a throttle (electric) motor 6 shaft. And a flexible wire that transmits the rotation of the throttle motor 6 to the disc-shaped throttle lever 3. The throttle motor 6 reads a fuel supply signal to the engine 1 set by the first potentiometer (volume) 10 based on a target rotation speed map A (a target rotation speed curve selected from the below) which is read and stored. An angle drive is performed by an output of a microprocessor (controller) 9 for calculating a target rotation speed. Reference numeral 8 denotes the position of the throttle motor 6, that is, the throttle motor 9
A second potentiometer for detecting the rotation angle of the shaft;
The position signal of the throttle motor 6 detected by the potentiometer 8 is calculated by a throttle motor position map B which substantially reversely converts the target rotation speed map A (a target rotation speed curve selected from the target rotation speed map A), and the output thereof is converted by a microprocessor 9. Will be fed back.

Now, if, after selecting a target speed curve A ₁ of the target rotation speed map A by the key switch a ₁ of the microprocessor 9, the lever 11 position of the first potentiometer 10 10 _1, 10 ₂
・ ・ ・ 10n (in the figure, lever 1 of the first potentiometer 10)
As first position, is operated to substantially indicated) Example 10 ₁ to 10 _6, operation along the same target rotational speed curve (mapped) A ₁ is performed, the rotation number 9 _1, 9 ₂ · · · 9n are respectively It is output from the microprocessor 9 as the optimum rotational speed in the state and is applied to the throttle motor 6.

Note that the target rotation speed map A is set so as to be an optimum condition corresponding to the type of the working machine driven by the special vehicle engine 1 and / or the working state of the working machine.
For example, a plurality of target rotation speed curves (maps) A ₁ , A ₂ ... An are created by actually operating various working machines from the engine 1 and measuring values corresponding to the respective working machines. A desired speed curve (for example, A ₂ ) is manually selected according to the work purpose of the engine 1 and is stored in the microprocessor 9 in advance, and the engine is driven to perform required work.

Incidentally, a plurality of target engine speed curve A _1, A ₂ ··· An of the target rotational speed map A, for example, the target rotational speed curve for excavators buckets capacity 1m ³ (A _2), the same 2m ³ Target speed curve for power shovel (A ₂ ) or maximum loading weight 20
If the target rotation speed curves A ₁ , A ₂ ... An are divided and stored in advance on separate floppy disks like the target rotation speed curve (An) for For each operation, the optimal target speed curve A ₁ , A _2.
.. By selecting a floppy disk storing any one of An and mounting it on the microprocessor 9, the target rotation speed curves A ₁ , A ₂ stored on the floppy disk are selected.
... An is driven by any one of An, that is, a target rotation speed curve along the optimum operation condition of the work machine.

Further, the microprocessor 9 is provided with an actual engine speed-throttle motor position map B as shown in FIG.
(In this map B, the operation is substantially the reverse of that of the map A.) That is, when the actual rotational speed of the engine 1 is _{9 11 ~9 16, 9 1 n} , are those that the throttle motor 6 position is 8 ₁ to 8 _6, 8n, also in the slot Louis position map B The output signal of the second potentiometer 8 is fed back to the microprocessor 9.

Incidentally, the Surotorumota position map in B, 8 ₁ denotes a throttle motor 6 position is 0 ° state, i.e., the 0% movement position, 8 ₆ maximum angle of the motor 6, i.e., a 100% movement position.

(Operation of the Embodiment) First, when the output (electrical quantity) Vout is applied to the microprocessor 9 by operating the lever 11 of the first potentiometer 10 for setting the fuel supply amount as an input device, the key (switch) a ₁ , a ₂ ... An, the type of the working machine driven by the special vehicle engine 1 and / or its working state from the plurality of target rotation speed curves A ₁ , A _2. In light of this, an optimal one (for example, A ₂ ) is selected, and fuel is supplied along the target rotational speed curve A ₂ , in other words, an amount corresponding to the optimal engine rotational speed for the work by the work machine. As shown in FIG.
The output command signal is applied to the throttle motor 6 to rotate the throttle motor 6 by a required amount, and the pulley 5 on the axis of the throttle motor 6 rotates the disc-shaped throttle lever 3 via the flexible wire 4.
Is rotated to adjust the amount of fuel supplied to the engine 1, and the work machine is operated at an optimum speed for work.

Further, in this embodiment, the first potentiometer 10 is used.
The low-resistance region 10 ₁ to 10 ₂ and the high-resistance region ₁₀₅ to height on both sides of the resistance region and ₆ (see hatched application region of FIG. 2)
The (upper limit of normal operating region, the non-operating area outside beyond the lower limit) and the disconnection detection range, only the output signal from between regions 10 ₃ ~10n~10 ₄ except these, the target rotation speed map A microprocessor 9 It is applied to the selected target rotation speed curve A ₂ (the setting example) as a normal operation region, and is processed so as to be driven at the optimum rotation speed in the work state by the work machine, and the output is throttled. Since the voltage is applied to the motor 6, depending on the position of the lever 11 of the first potentiometer 10, the sensitive first potentiometer 10 is disconnected (the height of the first potentiometer 10 corresponding to the hatched area in FIG. 2). Resistance area 10 on both sides
_{In 1} to 10 ₂ and 10 ₅ to 10 ₆ ), it is easily detected whether it is in a non-operating state or area (non-operating area) or in a normal operating state area.

Also, during the output from the first potentiometer 10 to the microprocessor 9, the fuel supply amount (corresponding to the target rotation speed) set by the first potentiometer 10 and the second potentiometer 8 detect and feed back. If the difference from the actual position (current value) corresponding value of the throttle motor 6 does not change for a predetermined time or more, there is a possibility that the throttle motor 6 is burned. , The control program of the microprocessor 9 is configured to limit the motor drive.

Note that the target rotation speed map A shows the relationship between the output of the first potentiometer 10 and the target rotation speed of the engine 1 in a linear relationship A ₁ (see FIG. 3) and a curve relationship of different curvatures.
A ₂ , A ₃ ... An (only the curve A ₂ is schematically shown in FIG. 3).

Further, the fuel supply amount control apparatus, using 5% to 95% range of the total resistance of the first potentiometer 10 (variable range of the second Vout) as (normal) operation region, ₁₀₅
Non-operating area in the range of less than 5% and more than 10 ₄ = 95%
That is, by setting the disconnection region, the 5-95% range (variable range of Vout in FIG. 2) is used as a (normal) operation region, for example, as a control signal for a pump or an engine due to a rotational speed deviation. The present invention can be applied to control means other than control of the fuel supply amount.

Here, according to the throttle motor position output map B,
The replacement effect on the rotation speed will be described.

(1) This and the throttle motor position map B, the combination of the target rotation speed map A, maximum 9 ₄ target RPM of the engine 1, it is possible to change the minimum value 9 ₃ Te extensively Dan'.

(2) If a disconnection state occurs in the first potentiometer 10 (less than 5% and more than 95% in the previous example), the range of the normal operation state set by the target rotation speed map A of the microprocessor 9 ( In this example, a signal indicating that the state has been removed from 9 ₃ ... 9 ₄ ) is transmitted.
It can be switched to the safe rotation state.

(3) The setting of the fuel supply amount (target rotation speed) by the first potentiometer 10 and the fuel supply amount corresponding to the change in the position of the throttle motor 6 that rotates correspondingly change the type of the working machine and / or A plurality of preset target rotation speeds to optimally respond to the work condition
Since it can be selected from the target rotation speed map A including A ₁ , A ₂ , A _3, ... An, the throttle motor 6 and the engine can be protected from excessive input, and the throttle motor 6 can be protected.

In FIG. 5, the output value Vout of the first potentiometer 10 is equal to Vo in the target rotation speed map A (FIG. 3).
The rotation number N corresponding to ut is output.

In addition, Low I in the selected target speed curve An
The dl Limit value: Nmin is compared with the High Idl Limit value: Nmax. If Nmin ≦ Ni ≦ Nmax, Ni is output as it is, and if Ni <Nmin, Ni> Nmax, Nmin and Nmax are Are output as Ni in the operating state.

On the other hand, the voltage is also applied to the low-region-side disconnection detection unit and the high-region-side disconnection detection unit at the same time, and Vout is set to the low-region-side disconnection detection reference value Vl.
(10 ₂ ) (less than 5% in the previous example) and the high region side disconnection detection reference value Vh (10 ₅ ) (more than 95% in the previous example), and if Vout ≦ Vl or Vout ≧ Vh, the first potentiometer It is judged that 10 is in the disconnection state, and in the case of, the Low Idl Limi
When the t value Nmin is set to, the High Idl Lim
The it value Nmax is output, and when Nmax is output, it is compared with Ni by Nmin selection, and Nmax is output. When Nmin is output, it is compared with Ni by Nmin selection and Nmin
Is output.

In FIG. 2, the lower limit value 10 ₃ and the upper limit value 10 ₄ of the signal output Vout of the first potentiometer 10 are the lower resistance side disconnection detection reference value 10 ₂ and the higher resistance side disconnection detection reference value 10 _5.
Can be configured to substantially correspond to each other.

If it is determined that the first potentiometer 10 is disconnected, a required target rotation speed can be output from the target rotation speed map A of the microprocessor 9.

In this embodiment, the first potentiometer is used.
The setting range of the target rotation speed by 10, that is, the limit values Nmin and Nmax of the variable range Vout of the lever position 10n in FIG.
Within the range between the low-frequency side disconnection detection reference value Vl (10 ₂ ) and the high-frequency side disconnection detection reference value Vh (10 ₅ ),
Depending on the type of the working machine driven by the engine and / or the working machine driven by the engine, such as selecting at the center part as shown in the figure, selecting below (lower area side) or above (higher area side) the figure It can be selected to appropriately respond to the work state or the like.

Further, even if it is undeniable that the output characteristics of the engine 1 are somewhat sacrificed, it is necessary to pay particular attention to focusing on the operating state of the working machine driven by the engine 1. In the range between the low-frequency disconnection detection reference value Vl and the high-frequency disconnection detection reference value Vh, Vout of the variable range 10n as a normal operation range in FIG. , Upper part (high frequency side)
It is also possible to set the target rotation speed region as a normal or normal operation region only in a region that is considerably fluctuated, such as by selecting only the lower region (low frequency side).

(Effects of the Invention) Since the present invention has the above-described configuration and operates, the following specific effects can be obtained.

(1) A setting value of the first potentiometer for setting the fuel supply amount is selected from a storage unit of the microprocessor that stores a target rotation speed map corresponding to the type of the work machine and the operation state of the work machine, The throttle motor is driven so as to be able to supply the optimum fuel in the operation state, and the position of the throttle motor or a throttle lever driven by the throttle motor is detected by a second potentiometer, and the throttle motor position or the throttle motor position by the second potentiometer is detected. A detection signal of a throttle lever position driven by the throttle motor is fed back to the microprocessor to automatically control the engine of the special vehicle so as to be suitable for the working machine or the operating state of the working machine. So, before Even when either the first potentiometer or the throttle motor is replaced, the working machine driven by the special vehicle engine or the optimum speed in the operating state by the working machine and the working machine Thus, the working machine can be driven by controlling the amount of fuel supplied to the engine for the special vehicle without fear of adverse effects due to departure from a normal driving state.

(2) From the target rotation speed map stored in advance in the microprocessor, the key switch of the microprocessor selects the work machine or a target rotation speed curve optimal for the operation state of the work machine, and selects the microprocessor. Calculates the type of the working machine and / or the optimal fuel supply amount for the working state by the working machine, and drives the throttle motor or the throttle lever via the throttle motor based on the output of the calculated value, thereby controlling the engine. Since the operation is controlled by controlling the fuel supply amount, for example, under a medium-to-low speed operation state of an engine for a crane specification vehicle, work by various work machines is performed by each work machine, or Operation based on the optimal conditions in the operating state can be performed.

(3) When driving different types of work machines and / or work machines of different capacities by the same special vehicle engine, the work machine is operated by a key switch of the microprocessor from a target rotation speed map stored in advance in the microprocessor. While selecting a target rotation speed curve such as the maximum and minimum rotation speeds corresponding to the model and / or its capacity, the first potentiometer restricts the operating range of the engine in advance,
Consequently, the work machine is operated under the optimal conditions (operating area).
, And can be safely driven.

(4) A fuel supply amount set value by the first potentiometer is selected from a target rotation speed map stored in the microprocessor in advance by using a key switch to select a target rotation speed curve optimal for the work state of the work machine. Since the value calculated by the microprocessor is applied to the throttle motor to drive it, the resistance for controlling the speed of the engine is focused on the work state of the work machine by a manual switch or the like, as in the conventional example. Therefore, it is not necessary to adjust each time so as to correspond to each operation state, and accordingly, the operation state of the working machine by the same engine, in particular, different working machines by the same engine is operated according to the optimum operation state. it can.

(5) By combining the target rotation speed map A and the throttle motor position map B stored in the microprocessor in advance, the maximum and minimum values of the target rotation speed of the engine can be selected over a wide range. Thus, driving suitable for a wide range of different working machines and different operating states can be performed.

(6) The setting of the fuel supply amount (based on the target rotation speed curve) by the first potentiometer and the fuel supply amount corresponding to the change in the position of the throttle motor that rotates correspondingly correspond to the working machine driven by the engine. type and or as corresponding in an optimum state to the working state, a plurality of target speed hexene a ₁ that is set in advance, a _2, a target selected from the target rotational speed map a containing ₃ · · · an in Since the throttle motor can be set so as to follow the rotation speed curve, the throttle motor and the engine are not forcedly input, and the throttle motor is protected.

(7) The method of controlling the fuel supply amount in the engine for a special vehicle and the first potentiometer of the device for implementing the method are performed by setting the normal operation region and the non-operation region other than the normal operation state, that is, the normal operation region, By setting an area above and below the upper and lower limits of the normal operation area as an abnormal operation area or a disconnection detection area, only the output signal from the normal operation area of the first potentiometer is applied to the microprocessor, The throttle motor position (angle) is calculated from the target rotation speed map so as to follow a target rotation speed curve selected in advance, and the throttle motor is driven by the calculated value. Side, or the first potentiometer is outside its normal operating range, etc. A disconnection state around the first potentiometer or a non-operational state is immediately detected, and, consequently, the driving of the work machine by the special vehicle engine or the operation knitting state by the work machine is in an uncontrollable state based on the disconnection of the control circuit. Can be operated without fear of inadvertent driving (malfunction).

(8) With the lever of the first potentiometer, the normal operation area and the disconnection area as the abnormal operation area are
Since it is possible to select and set the working machine or the operating state in accordance with the operating state, the same special vehicle engine is used to select various working machines or the operating condition of the working machine in accordance with the optimal condition of the operating state. Control that can be operated easily.

(9) If a disconnection state occurs in the first potentiometer, it is determined that the first potentiometer has departed from the range of the normal operation state set by the target rotation speed line selected from the target rotation speed map of the microprocessor. The transmission of the signal immediately switches the engine to the safe driving state.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of an apparatus for implementing a method for controlling a fuel supply amount in a special vehicle engine according to the present invention. FIG. 1 is a schematic explanatory view of the entire apparatus, and FIG. 2 is an operation of the first potentiometer. FIG. 3 is an explanatory diagram of a target rotational speed map A for converting the output of the first potentiometer into a target rotational speed, FIG. 4 is an explanatory diagram of a throttle motor position map B corresponding to the actual rotational speed of the engine,
FIG. 5 and FIG. 6 are block diagrams for explaining the operation of the first potentiometer and the throttle motor. (Name of code) 1 ... Engine 3 ... Throttle lever 6 ... Throttle motor 8 ... Second potentiometer 8 ₁ ... Throttle motor position (0%: 0% movement position) 8 ₆ ...... Maximum angle of throttle motor (100% movement position) 9 ...... microprocessor (controller) 91 _to 93 ₆ ...... optimum rotating speed (output to the throttle motor) 9 _11, 9 ₁₆ ...... actual rotational speed 10 ...... first potentiometer 10 ₁ - 10 ₂ …… Low resistance side (lower limit side) disconnection detection range 10 ₃ …… Position equivalent to low idle limit rotational speed 10 ₄ …… Position equivalent to high idle limit rotational speed 10 ₅ to 10 ₆ …… High resistance side (upper limit side) disconnection detection range 11 ... (the first potentiometer) lever a ...... target rotation speed map a _1, a ₂ .about.An ...... target speed curve a _1, a ₂ ~an ...... key switch B ... throttle motor position map B _1, B ₂ ...... Sulo Torumota position map Vout ...... output value of the first potentiometer (normal operating region)

Claims (3)

(57) [Claims] A first potentiometer for setting an amount of fuel supplied to an engine for a special vehicle; and a microcontroller for storing in advance a target rotation speed map corresponding to a type of a working machine driven by the engine and / or a working state of the engine. By a processor and a key switch of the microprocessor, from a target rotation speed map stored in the microprocessor,
A target rotation speed curve corresponding to the operation state of the work machine is selected, and a target rotation speed corresponding to the operation state of the work machine is calculated by the microprocessor based on the selected target rotation speed curve. At the same time, the calculated target rotation speed is output from the microprocessor as a rotation angle of a throttle motor or a rotation angle of a throttle lever driven by the motor, and a rotation angle of a throttle motor operated based on the output value. Or controlling the fuel supply amount based on the lever angle, and detecting the throttle motor position or the position of a throttle lever driven by the throttle motor with a second potentiometer, and feeding back the detection signal to the microprocessor, In an operation state suitable for the work state by the work machine As described above, the amount of fuel supplied to the special vehicle engine is controlled such that the working machine is driven along the selected rotation speed curve of the target rotation speed map. A method for controlling a fuel supply amount in an engine for a special vehicle, comprising: A first potentiometer for setting an amount of fuel supplied to an engine for a special vehicle; and a micro-controller for storing in advance a target rotation speed map corresponding to a type of a working machine driven by the engine and / or a working state thereof. A processor, a key switch for selecting a target rotation speed curve corresponding to the operation state of the work machine from a target rotation speed map stored in the microprocessor, and a key speed switch based on the target rotation speed curve selected by the key switch. A target rotation speed corresponding to the operation state of the working machine is calculated by the microprocessor, and the target rotation speed is driven based on an output value of the calculated target rotation speed from the microprocessor, and the target rotation speed is supplied to the engine. A throttle motor controlling the fuel supply amount or a throttle motor driven by the motor. And a second potentiometer for detecting a position of the throttle motor or a position of a throttle lever driven by the throttle motor; and a detection signal of the throttle motor position or the throttle lever position by the second potentiometer to the microprocessor. The special vehicle engine, wherein the microprocessor is configured to automatically calculate and correct the fuel supply amount to the engine by the feedback so as to be suitable for the working state of the working machine. Fuel supply control device. 3. An operation area in which the first potentiometer normally corresponds to the type of the working machine driven by the engine and / or the working state of the working machine, and an upper and lower limit of the normal operating area or Claims: A lever provided for setting a region slightly separated from the upper limit or the lower limit upward or downward as a disconnection region as an abnormal operation region of the engine set by the first potentiometer. 3. The fuel supply amount control device for a special vehicle engine according to claim 2, wherein