JPH02199384A - Control device for electromagnetic proportional control valve - Google Patents

Abstract

PURPOSE:To detect an abnormality such as a defective operation, warn it, and improve reliability by judging the presence of the abnormality based on the fine vibration in the opening detected signal in the control device of an electromagnetic proportional control valve superimposed with fine vibration and adjusting the opening. CONSTITUTION:A control circuit 15 sets the necessary secondary air quantity and the target opening of an electromagnetic proportional control valve 1 based on various engine state signals from a detector group 13 via a drive processing circuit 14, fine vibration is superimposed by a control valve driving circuit 16, a current is fed to the coil of the electromagnetic proportional control valve 1, the opening is detected by an opening detector 9 and fed back to the control circuit 15 via a drive processing circuit 21 for feedback control. The opening detected signal is inputted to an abnormality judging circuit 22, the contained vibration component is compared with the fine vibration signal applied by the driving circuit 16, and the presence of an abnormality is judged. When the abnormality is judged, a warning device 55 is operated. The reliability of the opening control of the electromagnetic proportional control valve can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an electromagnetic proportional control valve.

[Prior Art] Conventionally, electromagnetic proportional control valves have been used, for example, for regulating secondary air in internal combustion engines. This is for adjusting the air-fuel ratio, increasing the amount of air for warming up, increasing and adjusting the amount of air supplied to the internal combustion engine when operating the cooling system, etc. The engine water temperature sensor detects the engine cooling water temperature, the 02 sensor detects the oxygen concentration of the exhaust gas to detect the operating state of the internal combustion engine, and various sensors detect the operation of the torque converter, power steering, air conditioning system, etc. The system detects the vehicle condition and controls the opening of the electromagnetic proportional control valve based on this information.

[Problems to be Solved by the Invention] However, in this type of device, if the electromagnetic proportional control valve malfunctions due to a foreign object getting caught, etc., the amount of air differs from the required amount, so for example, if the amount of air is large, There is a possibility that the vehicle will accelerate and, if the amount of air is small, decelerate, resulting in a disadvantage that the driver's sensation may be different.

An object of the present invention is to provide a control device for an electromagnetic proportional control valve that can detect and warn abnormalities such as malfunction.

[Means for Solving the Problems] The first invention is a control device for an electromagnetic proportional control valve that adjusts the opening degree of the electromagnetic proportional control valve while superimposing minute vibrations. an opening detecting means for detecting an opening, a determining means for determining the presence or absence of an abnormality based on minute vibrations in a detection signal by the opening detecting means, and an alarm means for warning an abnormality when the determining means determines that an abnormality exists. The gist thereof is a control device for an electromagnetic proportional control valve.

A second invention is a control device for an electromagnetic proportional control valve that adjusts the electromagnetic proportional control valve to a target opening, including an opening detecting means for detecting the opening of the electromagnetic proportional control valve, and an opening detection means for detecting the opening of the electromagnetic proportional control valve, and the electromagnetic proportional control valve is in a steady state. valve state determining means for determining whether the solenoid proportional control valve is in a steady state or in a transient state; The gist thereof is a control device for an electromagnetic proportional control valve, comprising a determination means for determining the presence or absence of an abnormality by comparing the values of It is.

[Operation] In the first invention, the determining means determines whether or not there is an abnormality based on minute vibrations in the detection signal from the opening detection means, and the alarm means issues an alarm when the determining means determines that there is an abnormality.

The second invention is characterized in that the determining means compares the target opening of the electromagnetic proportional control valve when the electromagnetic proportional control valve is in a steady state with the opening detected by the opening detecting means, and determines whether or not there is an abnormality. The alarm means issues an alarm when the determination means determines that there is an abnormality.

[First Embodiment] An embodiment in which the present invention is applied to an N magnetic proportional control valve for adjusting the amount of secondary air in an engine mounted on a vehicle will be described below with reference to the drawings.

FIG. 2 shows the electromagnetic proportional control valve 1. An air passage 2 is formed in the housing 1a of the electromagnetic proportional control valve 1.
One end is connected to an air supply source via an air cleaner or the like, and the other end is connected to an intake pipe of the engine. A valve seat 2a is formed in the middle of this air passage 2.
A bellows (opening/closing valve) 3 that can be opened and closed is provided.

A drive shaft 4 is connected to the bellows 3, and springs 5 and 6 generally bias the bellows 3 in the direction of closing. Further, a coil (electromagnetic solenoid) 7 and a fixed core 8a are arranged on the outer periphery of the drive shaft 4, and by applying current to the coil 7, a movable core 8b fixed to the drive shaft 4 is attracted. , the opening degree of the bellows (on-off valve) 3 is adjusted.

Further, the electromagnetic proportional control valve 1 is integrally provided with a differential transformer type opening detector 9 as opening detection means.

That is, the housing 9a of the opening detector 9 is attached to one end of the housing 1a of the electromagnetic proportional control valve 1, and the drive shaft 4 of the electromagnetic proportional control valve 1 extends within the housing 9a. A core 10 made of a magnetic material is attached to the end of the drive shaft 4.
is fixedly installed, and an excitation coil 1 is attached to the outer periphery of the core 10.
1 and a detection coil 12 are provided.

FIG. 1 shows the overall configuration of a control device for an electromagnetic proportional control valve 1.

The detector group 13 consists of a plurality of detectors, and each of these detectors is designed to detect the state of the engine and vehicle (not shown). The detector drive processing circuit 14 is the detector group 13
Each detector is driven, and the signals from the detector group 13 are input and processed. The control circuit 15 is composed of a microcomputer and executes various processing operations according to programs. Then, this control circuit 15 calculates the required amount of secondary air for the engine based on the signal etc. from the detector drive processing circuit 14, and sets the duty ratio to the coil 7 of the electromagnetic proportional control valve 1 according to the amount of air. demand.

The control valve drive circuit 16 turns the battery voltage on and off to the coil 7 of the electromagnetic proportional control valve 1 based on the required secondary air amount (duty ratio) of the engine according to the control circuit 15, and supplies the necessary current.

An example of a specific configuration of this control valve drive circuit 16 is shown in FIG. Diode 17 and resistor 18 for battery voltage
The transistor 19 and the resistor 20 are connected in series, and the coil 7 of the electromagnetic proportional control valve 1 is connected in parallel to the series circuit of the diode 17 and the resistor 18. Then, a duty ratio signal corresponding to the required secondary air amount of the engine from the control circuit 15 is input to the base terminal of the transistor 19, and transistors 1 to 19 are turned on and off, thereby
A sawtooth wave current is applied to the coil 7 of the electromagnetic proportional control valve 1 as shown in FIG. At this time, the current flowing through the coil 7 is adjusted by the duty ratio. That is,
In FIG. 4, the duty ratio (t2/1
In 1), a current of 0.8 A can be passed through the coil 7 as an average value, and the duty ratio (t3/ll
), an average current of 0.4 A can be passed through the coil 7.

In this way, the electromagnetic proportional control valve 1 is adjusted to a predetermined valve opening degree while causing minute vibrations by the applied current to the coil 7 with superimposed minute vibrations.

The control circuit 15 monitors the current of the power source used in the control valve drive circuit 16, and detects that a disconnection has occurred when the value of the power source current decreases.

When this disconnection is detected, a warning device 55 issues a warning about the disconnection.

Returning to FIG. 1, the control valve detector drive processing circuit 21 excites the excitation coil 11 of the opening detector 9, and
It is necessary to process the output from the detection coil 12 and output an opening degree signal of the electromagnetic proportional control valve 1 to the control circuit 15 and the abnormality determination circuit 22 as determination means. A specific configuration of this control valve detector drive processing circuit 21 is shown in FIG.

The oscillation circuit 23 is composed of resistors 24 to 28, a capacitor 29, and an amplifier 30, and oscillates at a frequency sufficiently higher than the frequency of minute vibrations (several 100 Hz) superimposed by the electromagnetic proportional control valve 1. The drive circuit 31 drives the excitation coil 11 of the opening detector (differential transformer) 9, and includes a resistor 32 and a transistor 33. The rectifying and smoothing circuit 34 rectifies and smoothes the output of the detection coil 12 of the opening detector (differential transformer) 9, and is composed of diodes 35, 36, capacitors 37, 38, and resistors 39, 40. .

Here, since the frequency of the oscillation circuit 23 is set to be sufficiently high compared to the frequency of the minute vibrations superimposed by the electromagnetic proportional control valve 1, the values of the capacitors 37, 38 and the resistor 39, 40 of the rectifying and smoothing circuit 34 are selected appropriately. By doing so, only the excavated frequency component of the oscillation circuit 23 can be smoothed.

The differential amplifier circuit 41 takes the difference between the rectified and smoothed voltages of both coils 12a and 12b of the detection coil 12 of the opening detector (differential transformer) 9, and is composed of resistors 42 to 45 and an amplifier 142. ing.

The low-pass filter circuit 46 is provided to assist when smoothing is insufficient in the rectifying and smoothing circuit 34, and includes a resistor 47.
48, a capacitor 49, 50, and an amplifier 51. As in the case of the rectifying and smoothing circuit 34, the values of the resistor 47.48 and the capacitor 49.50 are appropriately selected so that the rectifying and smoothing circuit 34 can remove the excavated frequency components of the oscillation circuit 23 that are insufficiently smoothed. It has become.

Further, a reference potential for the differential amplifier circuit 41 and the low-pass filter circuit 46 is created from the power supply voltage Vcc by resistors 52 and 53. The output terminal 54 is connected to the abnormality determination circuit 22 and the control circuit 15.

In FIG. 1, the abnormality determination circuit 22 is connected to the control valve drive circuit 1.
The amplitude of the oscillating component of the applied current 6 is compared with the amplitude of the oscillating component of the output voltage of the control valve detector drive processing circuit 21, and if the difference between the two is less than a predetermined set value, an alarm is activated. A signal is output to the alarm device 55 and control circuit 15.

A specific configuration of this abnormality determination circuit 22 is shown in FIG.

A signal from the output terminal 54 of the control valve detector drive processing circuit 21 is input to the input terminal 56 . The bypass filter circuit 57 is for extracting only signals related to minute vibrations of the electromagnetic proportional control valve 1, and is composed of capacitors 58, 59, a resistor 601, and an amplifier 61. The values of the capacitors 58 and 59 and the resistor 60 are determined so as to pass frequency components including the minute vibration frequency of the electromagnetic proportional control valve 1. Note that the reference voltage V ref is the power supply voltage Vcc
It is made by dividing by resistors 62 and 63.

The full-wave rectifier circuit 64 performs full-wave rectification of the output signal of the bypass filter circuit 57, and is composed of resistors 65 to 69, diodes 70, and 7L amplifiers 72 and 73. The peak hold circuit 74 is a circuit that peak-holds the peak value of the signal full-wave rectified by the full-wave rectifier circuit 64 according to instructions from the timing delay circuit 75, and includes capacitors 77'-80, resistors 81-85, and diodes 86-86. 8
8. Amplifier 891. It is composed of FET90.

The sample-and-hold circuit 91 samples and holds the peak value of the signal peak-held in the peak-hold circuit 74 according to instructions from the timing delay circuit 76, and includes resistors 92 to 94, a capacitor 95, and amplifiers 96 and 97.
, FET98, and diode 99.

Further, the output signal of the bypass filter circuit 57 is connected to the resistor 1.
00 to the comparator 101, and the reference voltage yre
The signal is shaped into a square wave by comparison with r.

The timing delay circuit 76 inputs the output signal of the comparator 101 and outputs signals delayed at the rise and fall of the signal to the sample and hold circuit 91.

This timing delay circuit 76 is connected to the inverters 102 to 11.
0, capacitor 111.112, AND circuit 113,1
14 and an OR circuit 115. The timing delay circuit 75 further delays the signal delayed by the timing delay circuit 76 and outputs the signal to the peak hold circuit 74. This timing delay circuit 75 is connected to the inverters 116 to 1.
It consists of a 201 capacitor 121 and an AND circuit 122.

On the other hand, in Fig. 6, 57", 64-.74.91-
are the bypass filter circuit 57, the full wave rectifier circuit 64,
This circuit has the same configuration as the peak hold circuit 74 and the sample hold circuit 91, and receives a signal from the control valve drive circuit 16 via the input terminal 123 and outputs the signal to the core 7 of the electromagnetic proportional control valve 1 according to the duty ratio. Extracts minute vibration components from the current value signal, performs full-wave rectification, peak hold, and sample hold processing.

The determination processing unit 124 includes a comparator 125, an AND circuit 126,
It is composed of an inverter 127, resistors 128 and 129, and a transistor 130. The comparator 125 inputs the signals from the sample and hold circuits 91 and 91-, and
Outputs a high level signal when the amplitude value based on the minute oscillation voltage detected by the opening detector 9 from the number hold circuit 91 is smaller than the amplitude value based on the minute oscillation current according to the duty ratio from the sample hold circuit 91'. do.

One input terminal of the AND circuit 126 is connected to the comparator 125.
The other input terminal 132 is connected to the timing circuit 9 (see FIG. 1) which outputs a high level signal when the electromagnetic proportional control valve 1 is fully open or not fully open. The AND circuit 126 operates when both signals are at high level, that is, when the electromagnetic proportional control valve 1 is not in the closed or fully open position and is in a state where it can open and close, and when the duty cycle in the control valve drive circuit 16 is When the amplitude based on the minute oscillation voltage detected by the opening detector 9 is smaller than the amplitude based on the minute oscillation current according to the ratio, a high level signal (signal @ indicating the occurrence of an abnormality) is output. AND circuit 1
The output of 26 is sent to an inverter 127. Resistance 128, 129,
1 to the output terminal 1 after being amplified by the transistor 130
33 to the control circuit 15 and alarm device 55.

In FIG. 1, the timing circuit 131 is the control circuit 15.
The duty ratio signal is inputted, and it is determined based on the value whether the electromagnetic proportional control valve 1 is fully open or not fully open. A high-level signal indicating that the electromagnetic proportional control valve 1 is fully open or not fully open is output to the AND circuit 126 of the abnormality determination circuit 22.

The alarm device 55 inputs a signal from the abnormality determination circuit 22 to notify the driver that an abnormality has occurred in the electromagnetic proportional control valve 1.

Next, the operation of the control device for the electromagnetic proportional control valve configured as described above will be explained based on FIG. 7.

First, the control circuit 15 reads the correction term, each constant, etc. in step 201, and outputs each constant to the peripheral circuit in step 202 for initialization. Then, the control circuit 15 performs step 2.
At step 03, the presence/absence data of an abnormality is read from the abnormality determination circuit 22, and if it is determined that there is an abnormality at step 204, the process proceeds to step 20.
5 initializes the peripheral circuit constants.

If there is no abnormality in step 204, the control circuit 15 reads the value of the detector group 13 from the detector drive processing circuit 14 in step 206, and calculates the secondary air amount based on the value of the detector group 13 in step 207. Add the correction term to find the required amount of secondary air. Roughly, in step 208, the control circuit 15 determines the lift base (target valve opening degree) La and the set value (duty ratio) of the control valve drive circuit 16 for the secondary air amount.
is calculated and output to the control valve drive circuit 16 in step 209. As a result, the transistor 19 of the control valve drive circuit 16 is driven at a predetermined duty ratio, and at this time, the current flowing through the coil 7 has a sawtooth waveform (see FIG. 4). In response to this waveform, the electromagnetic proportional control valve 1 repeats minute vibrations, and the core 10 of the opening detector 9 that is integrated with it also moves in the same way, so the output of the opening detector 9 also becomes a signal with the same waveform. Become.

At this time, the movable parts (bellows 3, movable core 8b).

In the unlikely event that the core 10) malfunctions, that is, sticks, due to a foreign object being caught in the core 10), the amplitude of the vibration component of the output of the opening detector 9 disappears, and this is detected by the abnormality determination circuit 22 as an abnormality. Ru. Further, at the same time as the abnormality is detected, it is also output to the alarm device 55, and the malfunction is notified to the driver by the activation of the alarm device 55.

Here, in this embodiment, since the vibration component (ripple) of the current flowing through the coil 7 of the electromagnetic proportional control valve 1 and the vibration component of the output of the opening detector 9 are compared, the electromagnetic proportional control valve 1 is still Detection is possible from a state where the stick is not completely stuck and is starting to become sticky.

In step 210, the control circuit 15 reads the lift amount (detected valve opening degree) Lb from the control valve detector drive processing circuit 21.
In step 211, the target lift mLa and the detected lift ilb are
The difference A (=La - Lb) is calculated. Then, in step 212, the control circuit 15 determines that the lift amount difference A is α>
Determine whether it is A, α>A>-α, or -α> (however,
α is a predetermined value) If α>A, the control circuit 15 performs step 2.
In step 13, -β is added to the correction term for the secondary air amount, and -α〉A
If so, in step 214 β is added to the correction term for the secondary air amount, and then the process returns to step 203.

By repeating steps 203 to 214, the opening degree of the electromagnetic proportional control valve 1 is adjusted by feedback control so that the target opening degree and the detected opening degree match.

As described above, according to this embodiment, the opening degree detector 9 detects the opening degree (lift seedling) of the N magnetic ratio side control valve 1, and the abnormality determination circuit 22 detects minute Determine the presence or absence of an abnormality based on the vibration, that is, compare the amplitude value of the minute vibration to the electromagnetic proportional control valve 1 and the amplitude value of the minute vibration detected by the opening detector 9, and if the difference becomes more than a predetermined value, It is determined that a malfunction (stick) has occurred due to a foreign object getting caught. When the abnormality determination circuit 22 determines that there is an abnormality, the alarm device 55 can notify the driver of the abnormality. In addition, when making a determination, the vibration component of the current flowing through the coil 7 of the electromagnetic proportional control valve 1 and the vibration component of the output of the opening detector 9 are compared.
It is possible to detect the state where the stick is not yet completely stuck and is starting to become close to sticking.

In the above embodiment, the amplitude value of the vibration component of the current flowing through the coil 7 of the electromagnetic proportional control valve 1 is compared with the amplitude value of the vibration component of the output of the opening degree detector 9, and if the difference between them exceeds a predetermined value, , it is determined that stick has occurred, but in order to detect almost complete stick of the electromagnetic proportional control valve 1, the amplitude value of the minute vibration component in the detection signal of the opening detector 9 is set to a predetermined constant value. Alternatively, the configuration may be simpler. Alternatively, the control valve drive circuit 16 may be controlled so that the control circuit 15 closes the electromagnetic proportional control valve 1 when it is determined that there is an abnormality. A so-called fail-safe function may also be provided.

Generally speaking, in the above embodiment, a differential transformer type detector is used as the opening degree detector 9, but a Hall element or an MRE element may also be used.

[Second example] Next, a second embodiment corresponding to the second invention will be described.

This embodiment differs from the first embodiment in that 1) the timing circuit determines the steady state and transient state of the electromagnetic proportional control valve 1, and (2) the determination of the presence or absence of an abnormality uses minute vibrations. The difference is that the removed target opening value is compared with the detected opening value.

FIG. 8 shows the overall configuration of the control device for the electromagnetic proportional control valve.

Hereinafter, components having the same configuration as those of the first embodiment will be denoted by the same reference numerals, and detailed explanation thereof will be omitted.

The control circuit 134 serving as a determination means compares the target opening degree and the detected opening degree of the electromagnetic proportional control valve 1, and determines the difference between the target opening degree and the detected opening degree of the electromagnetic proportional control valve 1. When the opening detector 9 exceeds a certain set value which is beyond the range of error in manufacturing, temperature, etc., the occurrence of an abnormality such as disconnection or sticking in the electromagnetic proportional control valve 1 including the opening detector 9 is detected. Steady state determination circuit 135 as valve state determination means
determines whether the electromagnetic proportional control valve 1 is in a steady state or a transient state,
This is for determining the presence or absence of an abnormality in a steady state. In other words, in a transient state, the output value of the control circuit 134 and the output value of the control valve detector drive processing circuit 141 may differ due to a delay in the response of the electromagnetic proportional control valve 1, so this can be avoided. There is.

A specific configuration of this steady state determination circuit 135 is shown in FIG. 9, and the circuit 135 determines whether the output value of the control circuit 134 does not fluctuate for a predetermined period. That is, the opening command output of the control circuit 134 is divided into two parts, one of which is input to the difference circuit 136, and the other is input to the difference circuit 136 via the analog switch 137 and the hold circuit 138. The analog switch 137 is activated by a reset signal output from the determination circuit 139 or the counter circuit 140, and the hold circuit 138 holds the output value of the control circuit 134 when the analog switch 137 is turned on. The difference circuit 136 calculates the difference between the value from the hold circuit 138 and the output value of the control circuit 134 to which it is directly input.

The determination circuit 139 inputs the output signal of the difference circuit 136,
It is determined whether the value is within a predetermined range, and if it is within the predetermined range, a reset signal is output to the counter circuit 140. On the other hand, when the determination circuit 139 is out of the predetermined range, it outputs a reset signal to the analog switch 137 to turn on the switch 137. The counter circuit 140 counts the output time of the determination circuit 139 and determines whether a predetermined time has elapsed. This time is set to a value that sufficiently exceeds the response delay of the electromagnetic proportional control valve 1, and when the counter circuit 140 reaches a predetermined value, it outputs a signal to the control circuit 134 and also outputs a reset signal to the analog switch 137.

Therefore, steady state determination circuit 135 operates as follows. The output value of the control circuit 134 is held in the hold circuit 138 via the analog switch 137, and it is checked whether the new output value of the control circuit 134 has not fluctuated with respect to this value, and whether the difference between the two is within a predetermined range. It is determined by the difference circuit 136 and the determination circuit 139 that if there is no fluctuation, the counter circuit 140 counts the time period I~, and when the non-fluctuation state continues for a predetermined period of time, it informs the control circuit 134 that it is in a steady state. At the same time as the signal shown is output, the analog switch 137 is reset and the determination is started again. Further, when the determination circuit 139 detects a fluctuation, the counter circuit 1
40 and analog switch 137 are reset.

The control valve detector drive processing circuit 141 has a configuration similar to that shown in FIG. However, the cutoff frequency of the low-pass filter circuit 46 is set lower than that of the first embodiment. In other words, the cutoff frequency is determined by the opening detector (
It is lower than the excavation frequency of the excitation coil 11 of the differential transformer) 9, and even lower than the frequency of minute vibrations of the electromagnetic proportional control valve 1, for example, several tens of H2, which is a frequency that can sufficiently respond during engine transients. .

Next, the operation of the control device for the electromagnetic proportional control valve constructed in this way will be explained based on FIG. 10.

First, the control circuit 134 reads correction terms, name constants, etc. in step 300, and outputs each constant to the peripheral circuit in step 301 for initialization. Then, the control circuit 134 reads the value of the detector group 13 from the detector drive processing circuit 14 in step 302, calculates the secondary air amount from the value of the detector group 13 in step 303, adds a correction term to it, and adds the necessary Next, find the amount of air. In step 304, the control circuit 134 calculates a lift value (target valve opening degree) La for the secondary air amount and a set value (duty ratio) for the control valve drive circuit 16. First, the control circuit 134 outputs a signal to the transistor 19 of the control valve drive circuit 16 in step 305.

As a result, the electromagnetic proportional control valve 1 is driven at a predetermined duty ratio, and at this time, the current flowing through the coil 7 of the electromagnetic proportional control valve 1 has a sawtooth waveform as shown in FIG.

In response to this waveform, the electromagnetic proportional control valve 1 repeats one minute movement, and the core 10 integrated with it also moves in the same way, so the output of the opening detector 9 also has a range of minute vibrations.

Then, the output from the opening detector 9 is taken into the control valve detector drive processing circuit 141, which combines the oscillation vibration component of the excitation coil 11 of the opening detector (differential transformer) 9 with the electromagnetic proportional control valve 1. The minute vibration components are removed and sent to the control circuit 134.

The control circuit 134 reads the lift base (detected valve opening degree) Lb from the control valve detector drive processing circuit 141 in step 306, and in step 307 reads the difference A between the target lift amount La and the detected lift base Lb (=La − Lb ) is calculated. Then, the control circuit 134 controls the target lift ff1 in step 308.
A predetermined value r is applied to the difference between La and the detected lift aLb.
Compare with.

If A>r, the control circuit 134 operates the electromagnetic proportional control valve 1 in response to a signal from the steady state determination circuit 135 in step 309.
Read whether it is a steady state or an unsteady state (transient state). Thereafter, if the control circuit 134 is in a steady state, the control circuit 134 activates the alarm device 55 to perform an alarm operation in step 310, and initializes the constants of the peripheral circuits in step 312.

Also, the control circuit 134 is in an unsteady state (transient state) in step 310 or in step 308.
If -r<A<r, it is determined in step 313 whether the lift amount difference A is α>A, α>A>-α, or -α>△. If α>A, the control circuit 134 performs step 314.
-β is added to the correction term for the secondary air amount in step 315, and if -α>A, β is added to the correction term for the secondary air amount in step 315, and then the process returns to step 302. Note that the value of r in step 308 is larger than the value of α in step 313.

As described above, in this embodiment, the steady state determination circuit 13
5 determines whether the electromagnetic proportional control valve 1 is in a steady state or a transient state, and determines the target opening (target lift amount) and detected opening (detected re-draw) when the electromagnetic proportional control valve 1 is in a steady state. (), and if it deviates from a predetermined range, it is determined that there is an abnormality, and the alarm device 55 issues an alarm. Therefore, in a transient state, the output value of the control circuit 134 and the output value of the control valve detector drive processing circuit 141 may differ due to a delay in the response of the electromagnetic proportional control valve 1, but this can be avoided and ensured. It is possible to determine whether there is an abnormality or not and notify the driver.

[Effects of the Invention] As described in detail above, according to the present invention, an excellent effect is achieved in that abnormalities such as malfunctions can be detected and warned.

[Brief explanation of the drawing]

1 to 7 are diagrams for explaining the first embodiment, in which FIG. 1 shows the electrical configuration of the control device for the electromagnetic proportional control valve, and FIG. 2 shows the electrical configuration of the electromagnetic proportional control valve and A cross-sectional view of the opening detector, Fig. 3 is an electric circuit diagram showing the control valve drive circuit, Fig. 4 is a time chart 1 to 1 showing signals to the electromagnetic proportional control valve, and Fig. 5 is a control valve detector drive. FIG. 6 is an electric circuit showing a processing circuit, FIG. 6 is an electric circuit of an abnormality determination circuit, FIG. 7 is a flowchart for explaining the operation, and FIG. 8 is an electric configuration of a control device for an electromagnetic proportional control valve of the second embodiment. FIG. 9 is an electric circuit of the steady state determination circuit of the second embodiment, and FIG. 10 is a flowchart for explaining the operation of the second embodiment. 1 is an electromagnetic proportional control valve, 9 is an opening detector as an opening detection means, 22 is an abnormality determination circuit as a determination means, 55 is an alarm S position as an alarm means, 134 is a control circuit as a determination means, 135 is a steady state determination circuit as a valve state determination means. Patent applicant Nippondenso Co., Ltd. Agent Patent attorney On 1) Hironobu No. 3vlJ

Claims (2)

[Claims] 1. A control device for an electromagnetic proportional control valve that adjusts the opening degree of an electromagnetic proportional control valve while superimposing minute vibrations, comprising an opening detection means for detecting the opening degree of the electromagnetic proportional control valve; Control of an electromagnetic proportional control valve characterized by comprising a determining means for determining the presence or absence of an abnormality based on minute vibrations in a detection signal, and an alarm means for warning of an abnormality when the determining means determines that there is an abnormality. Device. 2. A control device for an electromagnetic proportional control valve that adjusts the electromagnetic proportional control valve to a target opening degree includes an opening detection means for detecting the opening degree of the electromagnetic proportional control valve, and a means for detecting whether the electromagnetic proportional control valve is in a steady state or a transient state. and a valve state determining means for determining whether the valve state is abnormal by comparing the target opening of the electromagnetic proportional control valve when the electromagnetic proportional control valve is in a steady state with the opening detected by the opening detection means. 1. A control device for an electromagnetic proportional control valve, comprising: a determining means for determining the presence or absence of an abnormality; and an alarm means for warning an abnormality when the determining means determines that there is an abnormality.