JPS59160030A - Engine controlling apparatus - Google Patents

Abstract

PURPOSE:To prolong the service life and to improve the reliability of operation of an engine controlling apparatus, by eliminating sliding contact parts by using a variable inductance as a converter for converting the depth of depression of an accelerator into an electric signal, and constituting an oscillation circuit by use of the variable inductance. CONSTITUTION:A sensor coil 8 is connected to an accelerator pedal 7, and the coil 8 is also connected to a circuit 10 consisting mainly of an operational amplifier 9. The sensor coil 8 and the circuit 10 constitute an LR oscillation circuit for obtaining an oscillation signal the frequency of which is varied according to the depth of depression of the accelerator pedal. The output signal S1 of said LR oscillation circuit is afforded to a frequency measuring circuit 13, and a binary digital data D1 obtained in the circuit 13 is converted into an accelerator data D2 in a data processing circuit 14 and then furnished to a control unit 4. With such an arrangement, the speed of rotation of a diesel engine 2 is controlled by the control unit 4 by controlling a fuel control member in a fuel injection pump 3 according to the speed signal N, water-temperature signal T and accelerator data D2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine control device, and more particularly, to an engine control device that effectively prevents the engine from falling into a dangerous operating state when a failure occurs in the accelerator sensor of an electronically controlled engine. The present invention relates to a highly reliable engine control device.

An electronically controlled engine control device is configured to convert the operating amount of each operating member into a stain signal using various sensors, and perform optimal control of the engine based on the obtained electrical signal. In conventional engine control devices, potentiometers are likely to be widely used as this type of conversion element. For example, in order to electrically detect the amount of operation of the accelerator pedal, conventional devices of this type use a potentiometer connected to the accelerator operation mechanism so that the slider is displaced according to the amount of depression of the accelerator pedal. Furthermore, the potentiometer is configured to extract an electrical signal whose level changes according to the amount of depression of the accelerator pedal.

However, since potentiometers used for this purpose are placed near the machine, the environmental conditions are often poor, and defects in the sliding contact area can cause abnormalities in the output signal level. There was a danger that he might come. If an abnormality occurs in this type of sensor output in an electronically controlled engine, it is extremely dangerous, such as causing the engine to run out of control. has been proposed (Unexamined Japanese Patent Publication No. 5
7-24437, JP-A-57-26232).

However, all of these proposed engine control devices utilize a potentiometer as an element for detecting the amount of operation of the accelerator pedal, and the reliability of the device itself is not fundamentally improved in any way.

Therefore, an object of the present invention is to significantly improve the reliability of an accelerator pedal operation amount detector, and to effectively prevent engine operation from becoming uncontrolled in the event that a failure occurs in the accelerator pedal detection section. I made it possible to do so. An object of the present invention is to provide an engine control device.

The present invention provides an engine control device comprising an output means for outputting an electric signal indicating the amount of operation of an accelerator pedal, and controlling the operation of an internal combustion engine in response to at least the electric signal output from the output means. wherein the output means includes a sensor coil whose inductance changes depending on the amount of operation of an accelerator pedal, a circuit connected to the sensor coil and outputting a detection signal of a frequency corresponding to an inductance value of the sensor coil, and the detection signal. detecting means for detecting that the frequency of the accelerator pedal has become a value outside a predetermined range determined according to the movable range of the accelerator pedal; The present invention is characterized in that it includes means for setting the value to a predetermined value.

According to this configuration, since the amount of depression of the accelerator pedal is converted into the inductance value of the coil in the output means, it is possible to completely eliminate the sliding contact part from the output means, and electricity is generated according to the amount of accelerator operation. To significantly improve the reliability of an output means for outputting a target signal, and also to detect any malfunction in the operation of the output means to prevent the engine from running out of control. This makes it possible to configure an extremely reliable engine control device.

Hereinafter, the present invention will be explained in detail with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of an engine control device according to the present invention. The engine control device 1 includes a control unit (C/lJ) 4 for controlling the position of a fuel adjustment member (not shown) of a fuel injection pump 3 for injecting and supplying fuel to a diesel engine 2. The diesel engine 2 includes a speed sensor 5 for outputting a speed signal N indicating the engine speed and a water temperature signal T indicating the engine cooling water temperature.
A water temperature sensor 6 is connected to output the water temperature signal N, and a speed signal N and water temperature signal T are input to the control unit 4.

Reference numeral 7 indicates an accelerator pedal 1, and a sensor coil 8 connected to the accelerator pedal 7 is connected to a circuit 1° mainly composed of an operational amplifier 9.
The sensor coil 8 and the circuit 10 constitute an LR oscillation circuit for obtaining an oscillation signal whose frequency changes according to the amount of operation of the accelerator pedal 7. In the circuit 10, R1 to R8 are resistors, and the power supply +V is connected to the resistor R3,
A constant voltage divided by R4 is applied to the inverting input terminal of the operational amplifier 9, and a feedback resistor R is connected between the inverting input terminal of the operational amplifier 9 and its output terminal. . The output voltage of operational amplifier 9 is connected to resistor R7+
The voltage is divided by R8, taken out via the transistor 11, and applied to the output terminal 12 of the circuit 10. The output terminal 12 is also connected to one end of the sensor coil 8 and
The other end of the sensor coil 8 is connected to the power supply +V via a resistor R1. Then, sensor coil 8 and resistor R1
The potential at the connection point is applied to the non-inverting input terminal of the operational amplifier 9 via the input resistor R2.

The oscillation frequency of the LR oscillator configured as described above is determined by the inductance value of the sensor coil 8 and the resistance value of the resistor R1. The core 8a of the sensor coil 8 is configured to be displaced within the sensor coil 8 according to the amount of depression of the accelerator pedal 7, and therefore the output terminal 12
The frequency of the oscillation output signal S1 obtained from the oscillation output signal S1 changes depending on the amount of operation of the accelerator pedal 7. That is, this oscillation circuit converts the operation amount of the accelerator pedal 7 into the frequency of the oscillation output signal S1.

FIG. 2 shows a curve showing the relationship between the frequency f of the oscillation output signal sl and the depression amount (operation amount) M of the accelerator pedal 7. The accelerator pedal 7 is in a released state when M=Mi, and reaches its maximum depression amount when M=Mf. Then, when M = Mi, the frequency is set to fl, and when M = Mf, the frequency is set to f2.

As can be seen from Fig. 2, the frequency f is the accelerator depression amount M
is determined to decrease as f increases, and f≧f
1 indicates an idle operating state.

The oscillation output signal Sl is input to the frequency and number measuring circuit 13, and data D indicating the frequency of the oscillation output signal S1 at each time is input.
Frequency measurement circuit 13 where l is binary digital data
is output from. The data Dl is input to the data processing circuit 14 and processed as described below, and the data obtained as a result of the processing is input to the control unit 4 as accelerator data D2.

The control unit 4 is equipped with a microcomputer and outputs speed signals N, water temperature signals T, and accelerator data D! Accordingly, the fuel adjustment member in the fuel injection cylinder f3 is controlled to control the speed of the diesel engine 2.

Next, regarding the data processing circuit 14, the data processing circuit 14 has an operation amount Mi during idling shown in FIG.
A first data generation circuit 15 that outputs frequency data Diale corresponding to the frequency 11 of the oscillation output signal Sl when
and a second frequency data Dfall corresponding to the frequency f2 of the oscillation output signal S at the time of the maximum operation amount Mf.
The data D and the above-mentioned frequency data Diddler Dfull are provided with a selector 17.
are entered respectively.

The data D1 is also input to the data discrimination circuit 18, and the frequency f indicated by the data D1 is f≧fl.
Area 11f1>f≧f2 Area ■, /2>/≧f
3c=fz-Δf), f<fsc=f2-Δ
f) It is determined which region (2) the image is in. Here, Δf is a virtual operation amount M that is larger than the accelerator operation amount Mf.
This value corresponds to the accelerator operation amount ΔM which is the difference from u. From the data discrimination circuit 18, data A indicating the discrimination result is inputted to the data selector 17 as a data selection control signal, and when the frequency f is in the region I, the frequency data Diale is selected, and when it is in the region selects data Dl, and when it is in area ■, data Dfull
is selected, and when it is in the region (3), data D1ale is selected, and the selected data is outputted from the selector 17 as accelerator data D2 and inputted to the control unit 4.

When such data processing is performed, when the accelerator pedal is released (M=Mi), the data Di
d>e is output as accelerator data D2, and therefore, the engine 2 is controlled to be maintained at a predetermined idle speed state. The value of the accelerator operation amount M is obtained by moving the accelerator pedal within the normal operating range.
If it is between i and Mf, the accelerator operation amount M
Data Dl indicating a frequency corresponding to the frequency is output as is as accelerator data D3. Therefore, in this case, engine 2
The speed of is controlled according to the amount of depression of the accelerator pedal 7.

Since the value of the oscillation frequency f with respect to the maximum operation amount Mf of the accelerator pedal 7 is fl, even if the adjustment error of the circuit 10 is taken into account, the state of f > f s is usually inevitable. Therefore, the state where f>fs is a case where some kind of failure has occurred in the circuit part that detects the amount of accelerator operation, so in this case, the frequency data Diale is used instead of the data Dl.
is output as frequency data D2. As a result, even if a fault occurs in the circuit 10 or the sensor coil 8, etc., and the frequency value indicated by the data D1 becomes smaller than fs, the engine 2 will not cause an overrun state or become uncontrolled, resulting in a dangerous situation. Accidents such as falling into a dangerous situation can be prevented. Further, in this case, since the engine 2 is operating at an idle rotational speed, it is possible to run on its own, and the vehicle will not be unable to move.

In region ■, when the accelerator pedal 7 is at the maximum depression position, even if f < f z due to adjustment deviation, etc., the D 2 ” Diale is immediately established υ, even if there is no failure in the sensor coil 8 or circuit 10 This is a buffer area for preventing the engine 2 from reaching the idle rotational speed regardless of the situation, and data Dfull is given to the state of this area (2).

FIG. 3 shows a flowchart of a program when the data processing circuit 14 is configured using a microcomputer. To explain this flowchart, first, in step a, it is determined whether or not a predetermined abnormality flag F is set. If the abnormality flag F is not set, in step b, a determination is made as to whether a predetermined abnormality flag F is set. The data DI (see FIG. 1) is read, and it is determined whether the frequency f indicated by the data D1 is 11 or more (step C). If f≧fl, the accelerator pedal 7 is released;
Set the data Diale as frequency data D, step d), frequency data D! Output.

If the frequency f is smaller than fl, it is further determined whether it is smaller than fs (step f), and f≧f
In the case of 3, it is determined whether fz>f≧f3 (Stella 7'g). The discrimination result in step g is N
In the case of O, that is, when the value of f is in the region ■,
The content of the frequency data D2 is assumed to be the read data D1. In step h), after clearing a counter CT% provided in advance in the converter (step i), the data D2 is output.

If the determination result in step g is YES, set the content of frequency data D3 to Dfall, step j),
After clearing the counter CTR (step amount), data D2 is output.

If the determination result in step f is YES due to some fault occurring in the sensor coil 8 or the circuit 10, 1 is added to the contents of the counter CTR (step t), and then the contents of the counter CTH are A determination is made as to whether the tradeoff is a predetermined value (step m). If the determination result in step m is No, proceed directly to Stella fd; on the other hand, if the determination result is YES, an abnormality flag F is set in step n, and then step d
Proceed to. Therefore, the determination result at step fK is YES.
In any case, D2 = D1dle.

The above program is repeatedly executed at predetermined time intervals. Therefore, the determination result in step m is N.

In this case, in the next program cycle, if a NO answer is obtained as the determination result in step f, the contents of the counter CTR are set to 0 in step i or k. On the other hand, if a YES determination result is obtained several times in step f, the abnormality flag F is set in step n, so in the next program cycle, the determination result in step a becomes YES, and the frequency data D2 will be used from now on. Dial. It will be fixed at

That is, according to this program, as described above, when it is detected that the frequency of the oscillation output signal S1 is equal to or less than f3 consecutively, the abnormality flag F is set.
Since the rotational speed of the engine 2 is controlled to be the idle rotational speed, even if the determination result in step f happens to be YES due to the influence of noise or the like, the flag F is not immediately set. Therefore, due to failure of the detector etc.
Since the abnormality flag F can be set by reliably detecting the occurrence of the condition <ts, reliability can be significantly improved.

Although the above embodiment describes a control device for a diesel engine, the present invention is not limited thereto, and can be similarly applied to an electronically controlled gasoline engine to obtain similar effects. It is.

Furthermore, in the above embodiment, when f<f3, the data Dl
Although the data Diale is given to the control unit 4 instead of the data Diale, the present invention is not limited to this, and data indicating an appropriate accelerator pedal operation amount other than the data Diale may be given.

Furthermore, in the above embodiment, the data D1 is switched to the predetermined data Diale only when the frequency f falls into the region (■), but the manipulated variable ML, which is smaller than the manipulated variable Mi, is set as shown in FIG. , a frequency value f whose value corresponds to the manipulated variable ML. If the frequency range is too small, this may be detected and the content of the data indicating the accelerator pedal operation amount may be set to a predetermined value. in this case,
The range of ML≦M <M> (i.e., fo≧f>fl) is defined as a punch-a-zone, and if data Diddle is output as accelerator data D2 within this range, the link mechanism of the accelerator pedal, etc. Even if there are installation errors or adjustment errors, no problems will occur.

According to the present invention, as described above, a variable inductance is used as a converter for converting the operation amount of the accelerator pedal into an electric signal, and this constitutes an oscillation circuit, so there is no sliding contact part. The lifespan and reliability are significantly improved compared to conventionally used potentiometers, and since the amount of accelerator operation is converted into a frequency, it is easy to perform digital signal processing using a microcomputer or the like.

Furthermore, if the sensor output shows an abnormal value, this is detected and the content of the signal indicating the amount of accelerator operation is forcibly set to a predetermined value, thereby ensuring that the engine does not run. This also allows the engine to continue operating at an appropriate speed, which has the effect of allowing the engine to move on its own.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the engine control device of the present invention applied to a diesel engine, and Fig. 2 shows the frequency f of the oscillation output signal of the detection circuit shown in Fig. 1 and the operation of the accelerator pedal. A characteristic diagram showing the relationship with the quantity M, and FIG. 3 is a flowchart showing a program when the data processing circuit shown in FIG. 1 is configured by a microcomputer. 1... Engine control device, 2... Diesel engine,
3...Fuel injection pump, 4...Control unit, 5...Speed sensor, 6...Water temperature sensor, 7...
・Accelerator pedal, 8...Sensor coil, 1o...
Circuit, 13... Frequency measurement circuit, 14... Data processing circuit, 15... First data generation circuit, 16... Second data generation circuit, 18... Data discrimination circuit, Sl.
...Oscillation output signal, A. Dl...data, D2...accelerator data, Dia
le +Dfull...Frequency data. Patent Applicant: Diesel Kiki Co., Ltd. Agent, Patent Attorney: Masatoshi Takano Procedural Amendment (Spontaneous) 6゜April 15, 1980 Kazuo Wakasugi, Official of the Japan Patent Office 1, Case Indication Patent Application No. 58-31863 2. Name of the invention Engine-based fit device 3 Relationship with the case of the person making the amendment Patent applicant address 3-6-7+ Shibuya, Shibuya-ku, Tokyo! −Name
(333) Diesel Kiki Co., Ltd. Daisha Mochizuki-4, Agent address: 2nd floor, Tomowa Building, 3-4-16 Shiba, Minato-ku, Tokyo 105 ``Detailed Description of the Invention'' section of the specification and drawings single figure. (1) On the 8th line of the 6-dog statement box, correct the text ``inverted input terminal'' to ``non-inverted input terminal.'' (2) Correct the statement rf4fIJ on the 4th line of No. 9 of the specification to read "f≧fI". (3) Delete "or k" on page 13, line 18 of the specification. (4) Bright@# Page 15, line 6, ``You may do so. -1'' is corrected as follows. ``You may do so, only if the determination result in step m is NO, It is also possible to output data D2 before the result becomes YES.'' (5) Correct as shown in Figure 1 of the drawing. (that's all)

Claims (1)

[Claims] 1. An engine control device comprising an output means for outputting an electric signal indicating the amount of operation of an accelerator pedal, and controlling the operation of an internal combustion engine in response to at least the electric signal output from the output means. The means includes a sensor coil whose inductance changes according to the amount of operation of the accelerator pedal, a circuit connected to the sensor coil and outputting a detection signal of a frequency corresponding to the inductance value of the sensor coil, and a circuit whose frequency of the detection signal is set according to the inductance value of the sensor coil. a detection means for detecting a value outside a predetermined range determined in relation to a movable range of the accelerator pedal; and a detection means for detecting a value outside a predetermined range determined in relation to a movable range of the accelerator pedal, and forcibly setting data indicating an operation amount of the accelerator pedal in response to a detection result of the detection means. 1. An engine control device characterized by: i.