JPH02271037A - Fuel supply controller for special car engine - Google Patents

Abstract

PURPOSE:To actuate a device safely by providing a first potentiometer by which the amount of fuel supply is determined, and a second potentiometer by which a throttle motor position, etc. is detected, and by providing a means by which the detected signal is fed back to a microprocessor. CONSTITUTION:When the output of a first potentiometer by which the amount of fuel supply is determined is applied to a microprocessor 9 of an engine 1, the application is performed by selecting a kind of a working machine driven by the engine 1 provided with the microprocessor 9, or the optimal aimed rotational curve for the working condition. A throttle motor 6 position corresponding to the amount of fuel supply determined by the first potentiometer 10, or a throttle lever 3 position driven thereby is detected by a second potentiometer 8. The detected signal is fed back to the microprocessor 9, and is compared to the aimed rotational signal determined and applied by the first potentiometer 10, and the amount of the fuel supply is controlled so as to correspond to the kind of the working machine or to the working status on an optimal condition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a fuel supply amount control device for an engine for a special vehicle such as a power shovel or a crane.

(Conventional Techniques) As a conventional fuel supply amount control device for an engine for a special vehicle, for example, there is one as shown in Japanese Patent Publication No. 8620/1983.

This is a control device for a system that includes an engine whose speed is controlled by adjusting the V# of the fuel supply amount and a variable displacement hydraulic pump driven by the engine, and which outputs a target rotation speed signal of the engine. an operating device that generates a rotation speed, and an output rotation speed detection device of the engine, and an arithmetic 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 to the difference, A first system that generates a fuel injection amount command signal that satisfies a predetermined functional relationship based on the rotational speed deviation signal of this calculation device.
and a device for adjusting the fuel injection amount based on the command signal from the first function generator, and generates a control pressure command signal that satisfies a predetermined functional relationship based on the rotational speed deviation signal. A control pressure is determined from a command signal of the second function generator, and the control pressure is used to control the maximum value of the input torque of the variable displacement hydraulic pump with respect to the rotational speed deviation. It is designed to decrease as the amount increases.

In addition, a comparator compares the target rotation speed set by the target rotation speed setting device and the actual rotation speed detected by the actual rotation speed detector, and depending on the level of the comparison, the motor of the fuel supply amount control lever to the engine is There is also an engine control device for construction machinery that controls the amount of fuel supplied to the engine by turning on either a speed increase relay or a deceleration lever in a control circuit (see, for example, Japanese Utility Model Application Publication No. 1846/1983). ).

(Problem to be Solved by the Invention) However, in the conventional fuel control device for a special vehicle engine described in the above-mentioned Japanese Patent Publication No. 62-8620, the engine is controlled by adjusting the fuel injection amount, and the engine In a system that includes a variable volume hydraulic pump driven by a It accumulates in the control device corresponding to the specific type (capacity and type) of the variable displacement pump (work equipment) being driven, and the maximum No measures were taken to control the amount of fuel supplied to the engines so that engines with different capacities could be operated under optimal conditions.

In addition, in the device described in the above-mentioned Japanese Utility Model Application Publication 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 Although the target rotation speed can be changed and adjusted by operating the setting device, this adjustment requires manual operation using the target rotation speed setting device, and this is especially true when the same engine is used to drive different work equipment. No measures were taken to drive the engine under optimal operating conditions.

This invention has been made by focusing on the problems of the conventional example, and is a first method for setting the fuel supply amount of an engine for a special vehicle.
Even if either the potentiometer or throttle motor is replaced.

Work equipment, etc. driven by the same special vehicle engine,
In order to enable processing without impairing the work efficiency of other equipment, when controlling the fuel supply amount of the special vehicle engine with the first potentiometer, the special vehicle engine may be used to control different types of work equipment and/or their different types. By controlling it via a microprocessor equipped with a target rotation speed map that allows the engine to be driven under optimal conditions even under working conditions, the engine is controlled to operate in the vicinity of the high idle limit rotation speed of the engine set by the first potentiometer. , the area near the low idle limit rotation speed,
By setting the disconnection detection area of the first potentiometer, it is intended to provide a device that operates more safely than conventional fuel supply amount control devices for engines for special vehicles of the same type.

(Means for Solving the Problems) In order to solve the problems in the conventional example as described above, the present invention provides a first potentiometer for setting the amount of fuel supplied to an engine for a special vehicle; a macroprocessor having a target rotation speed map corresponding to the type and/or working condition of the working machine driven by the engine; a throttle motor to which the output calculated by the microprocessor is applied; and a throttle motor position. or a second potentiometer for detecting the position of a throttle lever driven by the throttle motor; and means for feeding back a detection signal such as the throttle motor position by the second potentiometer to the microprocessor; In the fuel supply amount control device for a special vehicle engine, which applies the output of the first potentiometer for setting the amount to a target rotation speed map that can be selected depending on the type of work equipment driven by the engine and/or its working condition, The vicinity of the high idle limit rotation speed range and the vicinity of the low idle limit rotation speed range of the engine, which are set by the first potentiometer, can be respectively set as the disconnection detection range of the first potentiometer.

(Operation) Since the present invention has the above-described configuration, when applying the output of the first potentiometer for setting the amount of fuel supplied to the special vehicle engine to the microprocessor of the engine, the microprocessor a throttle responsive to the fuel supply amount set by the first potentiometer, while selecting and applying a target rotation speed curve most suitable for the type of work equipment to be driven by the special vehicle engine and/or its working condition; The motor position or the throttle lever position driven by the throttle motor is detected by a second potentiometer, the detection signal is fed back to the microprocessor, and the first
The amount of fuel supplied to the special vehicle engine is controlled in accordance with the target rotation speed signal set and applied by a potentiometer so as to correspond to the type of work equipment and/or its working conditions under optimal conditions; If the first potentiometer is near the high idle limit rotation speed range or the low idle limit rotation speed range of the engine, it is determined that the first potentiometer is in a disconnected state, and the amount of fuel supplied to the special vehicle engine is By switching the operating state of the device, the device can be operated safely.

(Embodiment) Hereinafter, an embodiment of the fuel control device for a special vehicle engine according to the present invention will be described with reference to FIGS. 1 to 6.

In the figure, 1 is an engine for a special vehicle, 2 is its governor, 3 is a disk-shaped throttle lever (fuel lever),
A flexible wire 4 is stretched between the disc-shaped throttle lever 3 and a pulley 5 on the axis of the throttle (electric) motor 6, and transmits the rotation of the throttle motor 6 to the disc-shaped throttle lever 3. The throttle motor 6 is connected to the engine 1 set by a first potentiometer (volume) 10.
It is driven by a predetermined angle by the output of a microprocessor (controller) 9 that calculates a fuel supply signal to a target rotation speed. 8 is a second potentiometer that detects the position of the throttle motor 6, that is, the rotation angle of the 6 axes of the motor, and the position 4m of the throttle motor 6 detected by the second potentiometer is an abbreviation of the target rotation speed map A. The position of the throttle motor is calculated using the throttle motor position map B, which is inversely converted.

Now, after selecting the target rotation speed curve A1 of the target rotation speed map A using the key 81 of the microprocessor 9,
The lever 11 position of the first potentiometer 10 is set to 101.
10□...When Ion is operated, the same shelf rotation speed curve A
, 9, 9□, .

Note that this target rotation speed map A is based on, for example, the actual speed of various work machines driven by the engine 1 for special vehicles so as to correspond to the type of work machine driven by the engine 1 for special vehicles and/or its working conditions under optimal conditions. By operating the engine and measuring the corresponding values, multiple target rotation speed curves A can be created.
1, A2, .

Note that the target rotation speed map A has a plurality of target rotation speed curves A1. For example, the target rotational speed curve (A1) for a power shovel with a packet capacity of 1 port is 2-
For power excavators (A,), or maximum cargo handling load 20
If each target rotation speed curve is divided and stored on a separate floppy disk, such as the target rotation speed curve (An) for a ton crane, the optimal target rotation speed curve for the work equipment can be stored on a floppy disk for each work. By selecting the disc, each work machine can be driven at all times according to the target rotation speed curve under optimal conditions.

Further, the microprocessor 9 generates a map B between actual engine rotation speed and throttle motor position as shown in FIG.
Output according to the following. That is, the actual rotational speed of the engine 1 is between 9□1 and 91. .

When 9□n, the throttle motor 6 position is 8□~8
The output signal of the second potentiometer 8 based on the map B is fed back to the microprocessor 9.

In the same map B, 81 indicates that the throttle motor 6 is at an O degree position, that is, its 0% movement position, and 8 indicates the maximum angle of the motor 6, that is, its 100% movement position.

Next, the operation of this embodiment will be explained.

First, when applying the output (amount of electricity) Vout 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 keys aA, a2...an are used to apply the output (amount of electricity) Vout to the microprocessor 9. Among the plurality of target rotational speed curves A, A2..., the most suitable one (for example, A,) in light of the type of work equipment driven by the special vehicle engine 1 and/or its working condition, etc. is selected, and the microprocessor 9 calculates and outputs the command signal so as to supply an amount of fuel along this target rotation speed curve A2, in other words, to supply an amount of fuel corresponding to the optimum engine rotation speed for the work performed by the work machine. is applied to the throttle motor 6 to rotate it by a required amount, and the pulley 5 on the axis of the motor 6 rotates the disk-shaped throttle lever 3 via the flexible wire 4, thereby controlling the amount of fuel supplied to the engine 1. and operate the machine at the optimum speed for work.

Furthermore, in this embodiment, the first potentiometer 10
Low resistance range 101-10. and high side areas 10, ~10.
(Refer to the hatched area in Figure 2) is set as the disconnection detection range, and 10. Only the output signals from ~10n~104 are input to the target rotation speed map A of the microprocessor 9.
is applied to the selected target rotational speed tune mA2, the processing is performed so as to cause the working machine to operate at the optimum rotational speed for the working condition, and this output is applied to the throttle motor 6, so that the lever 11 Depending on the position of , the state of the # line on the first potentiometer 10 side can be easily detected.

Also, during the output from the first potentiometer 10 to the microprocessor 9, the fuel supply amount (target rotation speed) set by the first potentiometer 10 and the throttle motor 6 detected by the second potentiometer 8 and fed back. If the difference between the actual position II (current value) and the corresponding value does not change for a predetermined period of time or more, there is a risk of burnout of the throttle motor 6. To prevent burnout of the motor, the stop time of the throttle motor 6 may exceed the predetermined time. At this time, the control program of the microprocessor 9 is configured to limit the motor drive.

Note that the target rotation speed map A shows the output of the first potentiometer 10 and the target rotation speed of the engine 1 in a linear relationship A, as well as a curved relationship A2, A, etc. with different curvatures.
- Set as An.

Further, this fuel supply amount control device has a range of 5 to 95% of the total resistance of the first potentiometer 10 (V in FIG. 2).
Set the out range to 10. = 5%, 1° = 95%) as the operating region, it can be applied to control means other than fuel supply amount control, for example, by using it as a pump or engine control No. 48 based on rotation speed deviation. .

Next, the effect of replacing the throttle motor position output knob B on the rotational speed will be described.

(1) Based on the combination of this throttle motor position map B and the target rotation speed map A, the maximum value of the target rotation speed of the engine 1 is 94, the minimum value is 9. can be varied over a wide range.

(2) If a disconnection state occurs in the first potentiometer 10, a signal indicating that the normal operating state set by the target rotational speed map A of the microprocessor 9 has entered the state will be transmitted. , can immediately switch to the safe rotation state.

(3) Fuel supply amount by the first potentiometer 10 (
The target rotation speed) and the fuel supply amount corresponding to the change in the position of the rotating throttle motor 6 are set in advance so as to optimally correspond to the type of work equipment and/or work condition of the engine. Since the target rotation speed map A can be selected from the target rotation speed map A, the throttle motor 6 and the engine can be protected without being subjected to forced input.

Further, in FIG. 5, the output value Vout of the first potentiometer 10 outputs the rotation speed N corresponding to Vout in the target rotation speed map A (FIG. 3).

Furthermore, Low in the selected target rotational speed curve
Idl Lim1t value, NminHigh Id
l It is compared with the Lim1t value, Nm, ax, and if Nm1n≦Ni≦Nmax, Ni is output as is, and if N<Nm1n
, if N>Nmax, outputs Nm1n and Nmax, respectively.

On the other hand, it is simultaneously applied to the low-frequency side disconnection detection section and the high-frequency side disconnection detection section, and Vout is set to the low-frequency side disconnection detection reference value Vl (
10,), and high frequency side disconnection detection reference value Vh (10,)
If Vout≦v1 (2) or Vout≧vh (2), it is determined that the first potentiometer 10 is disconnected.

When ■, Low Idl L is detected from the low frequency side disconnection detection section.
im1t value Min, when ■, from the high frequency side disconnection detection section HighIdl L
im1t value Nmax is output, and if Nmax is output, it is compared with Ni by Nmln selection and Nmax
Output. When Nm1n is output, it is compared with Ni by selecting Nmln, and Nm1n is output.

Further, in FIG. 2, the lower limit value 10. of the signal output Vout of the first potentiometer 10. The upper limit value 104 is the lower resistance side wire breakage detection reference value 10□ and the higher resistance side wire breakage detection reference value 10. It is also possible to configure them so that they substantially match each other.

Note that, even if the first potentiometer 10 is disconnected, the microprocessor 9 can be configured to output a desired target number of rotations from the target number of rotations map A.

Note that in this embodiment, the first potentiometer 1
0, that is, the limit values Nm1n and Nmax of the variable range in FIG. ,), the type of work equipment driven by the engine, such as selecting the center part as shown in the figure, the lower side or the upper side of the figure, etc.
and/or can be selected to appropriately respond to the working conditions etc. of the working machine.

In particular, even if it is undeniable that the output characteristics of the engine will be sacrificed to some extent, in particular, when it is necessary to focus on the operating state of the work equipment operated by the engine, the Within the variable range of the low-frequency wire breakage detection reference value ■1 and the high-frequency wire breakage detection reference value vh, the target rotation speed is set only in fairly uneven areas such as only the center, only the top, and only the bottom. You can also set

(Effect of the invention) Since this invention has the above-mentioned structure and functions,
The following unique effects can be obtained.

(1) Since the value set by the first potentiometer for setting the fuel supply amount is applied to the throttle motor via a microprocessor equipped with a target rotation speed map corresponding to the working state of the working machine, the first potentiometer Even if either the engine or the throttle motor is replaced, the engine can be driven at the optimum speed without affecting other equipment, such as a working machine driven by the engine for the special vehicle.

(2) By setting the upper and lower limit areas of the first potentiometer as the disconnection detection areas, only the output signal from the center area of the first potentiometer is applied to the target rotation speed map, processed, and then sent to the throttle motor. Since the voltage is applied, a disconnection state on the first potentiometer side can be detected, and the working machine can be opened and operated by the special vehicle engine safely without any danger.

(3) Selecting and applying the output signal of the first potentiometer to a desired target rotation speed curve of the target rotation speed map;
Calculations are made to optimally correspond to the type of work equipment and/or working conditions, and the output is applied to the throttle motor, so for example, the work performed by each type of work equipment under medium- to low-speed operating conditions of the engine of a crane-spec vehicle can be performed individually. This can be done under the optimal conditions.

(4) When driving different types of work equipment and/or different capacity work equipment with the same special vehicle engine, determine the model and type of work equipment to be driven by the engine from the target rotation speed curve of the target rotation speed map set in advance. Alternatively, by selecting the maximum and minimum rotational speed corresponding to the capacity, the operating range of the engine can be restricted, and the working machine can be driven safely under its optimum conditions.

(5) The fuel supply amount setting value set by the first potentiometer is selected from the target rotation speed map to be the one that is most suitable for the working condition of the work equipment in question, and then applied to the throttle motor. There is no need to adjust the engine speed control resistance using a manual switch or the like while paying attention to the working state of the working machine, and the operability is significantly improved.

[Brief explanation of drawings]

The drawing shows one embodiment of the fuel supply amount control device for a special vehicle engine according to the present invention.
The figure is a schematic explanatory diagram of the entire structure. FIG. 2 is an explanatory diagram of the operation of the first potentiometer. Fig. 3 is an explanatory diagram of the target rotation speed map A that converts the output of the first potentiometer into the target rotation speed, Fig. 4 is an explanatory diagram of the throttle motor position map B corresponding to the actual rotation speed of the engine, and Fig. 5 and FIG. 6 is a schematic diagram illustrating the operation of the first potentiometer and throttle motor. 1... Engine, 3... Throttle lever, 6... Throttle motor, 8... Second potentiometer, 9...
Microprocessor (controller), ], O...
...First potentiometer, 10, ~102...
・Low resistance side disconnection detection range, 10, ~106...
High resistance side disconnection detection range. A...Target rotation speed map, A8, At...Target rotation speed curve, B...
・Throttle motor position map, Vout...
First potentiometer output value. Figure 3 Target rotation speed (RPM) Target rotation speed (RPM)

Claims (2)

[Claims] (1) First step to set the fuel supply amount of the special vehicle engine
a potentiometer; a macroprocessor to which the output of the first potentiometer is applied; and a macroprocessor comprising a target rotation speed map corresponding to the type and/or working condition of the working machine driven by the engine; a second potentiometer for detecting the throttle motor position or the throttle lever position driven by the throttle motor; and means for feeding back a detection signal such as the throttle motor position by the second potentiometer to the microprocessor; A fuel supply amount control device for a special vehicle engine, comprising: (2) A fuel supply amount control device for a special vehicle engine that applies the output of the first potentiometer for setting the fuel supply amount to a target rotation speed map corresponding to the type of work equipment driven by the engine and/or its working state. In this case, the vicinity of the high idle limit rotation speed range and the vicinity of the low idle limit rotation speed range of the engine set by the first potentiometer can be set as the disconnection detection area of the first potentiometer, respectively. A fuel supply amount control device for a special vehicle engine, which is characterized by: