JPH0612238Y2 - Engine throttle opening detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention sets the opening degree of a throttle valve which is arranged in an intake passage of an engine mounted on a vehicle and which is opened and closed according to an operation amount of an accelerator operating means. The present invention relates to an engine throttle opening degree detection device.

(Prior Art) In an engine mounted on a vehicle, for example, fuel supply amount control, ignition timing control, idle speed control, exhaust gas recirculation control, release control of evaporated fuel stored in a canister, and the like are performed. In some cases, it is required to directly and continuously detect the opening degree of a throttle valve that is opened and closed according to the operation amount of an accelerator operation means such as an accelerator pedal. As a sensor for directly and continuously detecting the opening of the throttle valve, for example, a linear throttle opening sensor (hereinafter simply referred to as a throttle opening sensor) as disclosed in JP-A-58-211547. It has been known.

Such a throttle opening sensor is usually provided with a potentiometer having a slider that rotates with opening and closing of a throttle valve, and an output obtained from the potentiometer is a detection output representing the opening of the throttle valve. It

(Problems to be solved by the invention) However, in the throttle opening sensor as described above, the throttle valve is idling open due to a manufacturing error that occurs during mass production, an assembly error when assembled to the engine, or the like. When the engine is in the open state, variations in the detected output are likely to occur, and even after the engine is assembled, the detected output in the idle ring opening state often changes due to aging. Therefore, when control of the engine such as fuel supply amount control using the detection output obtained from such a throttle opening sensor is performed,
There is a possibility that the detection output obtained from the throttle opening sensor and the actual opening of the throttle valve do not correspond to each other, which may cause a decrease in control accuracy.

As one measure for avoiding the problems as described above, for example, an idle switch that turns on or off when the throttle valve is placed in a specific state is provided and The opening of the throttle valve when the output according to the off state is obtained is considered as the idling opening, and it is obtained from the throttle opening sensor when the output according to the on or off state is obtained from the idle switch. It is conceivable that the reference output is set based on the detected output, and the detected output obtained from the throttle opening sensor is corrected based on the reference output.

However, regarding the specific state of the throttle valve in which the above-mentioned idle switch is turned on or off, the throttle valve is opened slightly larger than the idling opening to absorb the opening / closing error of the throttle valve. Therefore, the throttle valve opening somewhat larger than the idling opening is actually regarded as the idling opening. for that reason,
For example, even when the accelerator pedal is placed on the throttle valve and the throttle valve takes a state slightly larger than the idling opening degree, the throttle valve opening degree at that time is determined to be the idling opening degree. There is a possibility that the output may not be corrected properly.

In view of such a point, the present invention has a throttle opening sensor that generates a detection output according to the opening of the throttle valve, and even when the accelerator operation means is slightly operated,
It is prevented that this condition is erroneously determined that the throttle valve is in the idling opening state, and the reference is based on the detection output obtained from the throttle opening sensor when the throttle valve is in the idling opening state. An object of the present invention is to provide an engine throttle opening degree detection device capable of setting and storing an output and appropriately correcting the detected output based on the reference output.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the engine throttle opening detecting device according to the present invention has an intake air of an engine mounted on a vehicle, as its basic configuration is shown in FIG. In addition to the opening degree output generating means for generating a detection output according to the opening degree of the throttle valve arranged in the passage, a power transmission state detecting means for detecting the connection state of the power transmission path from the engine to the wheels in the vehicle, A braking detection means for detecting the operating state of the braking means mounted on the vehicle, and a detection output indicating that the power transmission path is in the connected state is obtained from the power transmission state detection means, and the braking detection means performs braking. The reference output setting means sets the reference detection output based on the detection output from the opening output generation means obtained when the detection output indicating that the means is in the operating state is obtained. The output correction means corrects the detection output obtained from the opening output generation means based on the stored reference output.

(Operation) In the engine throttle opening degree detection device according to the present invention configured as described above, the power transmission path from the engine to the wheels is in the connected state, and thus the vehicle is in the running state, and In view of the fact that the accelerator operating means is always opened when the braking means is in the operating state, the reference output setting means detects the connection state of the power transmission path from the engine to the wheels by the power transmission state detecting means. At the same time, the reference output is set and stored based on the detection output from the opening degree output generating means obtained when the operating state of the braking means is detected by the braking detection means, and the output correction means stores the reference output. The detection output from the opening output generating means is corrected based on the output.

By doing so, it is possible to avoid misjudging that the accelerator operation means is slightly operated as the idling opening state, so the accelerator operation means is slightly operated and the throttle valve is opened. The detection output of the opening output generating means when it is slightly opened from the normal state is not used as the basis of the reference output, and the detection output is properly corrected.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows an example of an engine throttle opening degree detection device according to the present invention, together with an engine to which it is applied.
In FIG. 2, in the intake passage 12 that guides intake air from the air cleaner 11 to the combustion chamber 14 of the engine body 10,
Throttle valve 1 that works with an accelerator pedal (not shown)
6 are arranged. The opening of the throttle valve 16 is detected by the throttle opening sensor 18. The throttle opening sensor 18 includes a potentiometer that produces an output according to the opening of the throttle valve 16, and the output produced by the potentiometer is supplied as a detection signal St to a control unit 100 which will be described in detail later. As shown in FIG. 3, the level V of the detection signal St is
Is linearly increased as the opening Th of the throttle valve 16 increases.

An air flow meter 20 for detecting the intake air amount is arranged on the upstream side of the portion of the intake passage 12 where the throttle valve 16 is arranged, and a detection signal Sa corresponding to the intake air amount detected by the air flow meter 20 is provided. Are supplied to the control unit 100. In addition, the intake passage 1
2, a surge tank 22 having a relatively large volume is provided on the downstream side of the portion where the throttle valve 16 is arranged, and a fuel injection valve 25 is provided on the downstream side of the surge tank 22. ing. Fuel injection valve 2
Reference numeral 5 is electronically controlled, and operates to open the valve in accordance with the pulse width of the injection pulse signal Pc supplied from the control unit 100. The fuel tank 17, the fuel pump 21, the filter 23, the fuel pressure regulator 24, etc. The fuel, which is regulated and pressure-fed from the fuel supply system configured by, is intermittently injected toward the intake port portion for the combustion chamber 14 at a predetermined timing, for example, in synchronization with the rotation of the engine. Creates a mixture for internal combustion.

The air-fuel mixture is supplied to the combustion chamber 14 via the intake valve 27,
The spark plug 28 ignites and burns. And
Exhaust gas generated by burning the air-fuel mixture in the combustion chamber 14 is discharged to the exhaust passage 26 via the exhaust valve 29,
The exhaust gas rotationally drives the turbine 42 of the turbocharger 40 interposed in the exhaust passage 26. A compressor 43, which is driven by a turbine 42 of a turbocharger 40, is interposed in the intake passage 12, and intake air is pressurized by the compressor 43 and supplied to the combustion chamber 14. Is done.

The exhaust passage 26 has a bypass passage portion 4 that bypasses the turbine 42.
4 is provided, and the bypass passage portion 44 is opened / closed by a waste gate valve 46 driven by a diaphragm mechanism 45. The waste gate valve 46 is adapted to respond to the negative pressure in the intake passage 12 upstream of the throttle valve 16. A catalytic converter 41, a silencer (not shown), etc. are arranged in a portion of the exhaust passage 26 downstream of the turbine 42.

Further, a portion of the intake passage 12 between the throttle valve 16 and the intercooler 39 is connected to a starting end portion of the bypass passage 15 that bypasses the throttle valve 16, and an end portion of the bypass passage 15 is located in the intake passage 12. It is connected to a surge tank 22 provided on the downstream side of the throttle valve 16. In the bypass passage 15, the flow rate adjusting valve 1
9 is installed, and the flow rate adjusting valve 19 is operated by the valve opening operation pulse signal Cq supplied from the control unit 100.
The bypass passage 15 is opened / closed in accordance with the pulse width of, and thereby the amount of intake air taken into the combustion chamber 14 is adjusted.

A rotation speed sensor 30 that detects the engine rotation speed is arranged in association with the crank mechanism 33 that converts the reciprocating motion of the piston 31 in the engine body 10 into a rotation motion. The detection signal Sn corresponding to the number is supplied to the control unit 100.

An evaporative fuel control device including a canister 50 and the like is attached to the engine having such a configuration. The canister 50 has an evaporative fuel adsorption / holding layer 52 using activated carbon or the like in the center thereof. In the canister 50, the evaporated fuel generated in the fuel tank 17 receives the tank pressure adjusting valve 5
4 and an orifice 55 are provided to feed through an evaporation passage 56. And the canister 50
The other end of the evaporated fuel discharge passage 60, one end of which is connected to the downstream side of the throttle valve 16 in the intake passage 12, is opened in the upper empty space of the other end of the evaporated fuel discharge passage 60. A diaphragm type negative pressure responsive valve 62 is used to open and close the nearby portion.

The diaphragm type negative pressure responsive valve 62 has a negative pressure introducing chamber 62
The evaporative fuel discharge passage 60 is opened when an intake negative pressure equal to or higher than a predetermined pressure is introduced through the negative pressure introduction passage 65 in which the first three-way solenoid valve 67 is interposed in a. The negative pressure introducing passage 65 is configured such that the starting end thereof opens to a portion upstream of the throttle valve 16 when the throttle valve 16 is in the fully closed state (idling opening state).

An orifice 68 is provided at the center of the evaporated fuel discharge passage 60.
And an auxiliary passage portion 72 that bypasses the orifice 68 is provided. The auxiliary passage portion 72 serves, for example, to guide a large amount of evaporated fuel to the intake passage 12 at the time of high load and high rotation, and the auxiliary passage portion 72 is provided with a diaphragm type negative pressure responsive valve 74 and an orifice 68 for opening and closing the auxiliary passage portion 72. An orifice 76 having a somewhat larger passage cross-sectional area is provided.
The diaphragm type negative pressure responsive valve 74 has a negative pressure introducing chamber 74a.
When the intake negative pressure of a predetermined pressure or higher is introduced through the negative pressure introducing passage 75 in which the starting end portion is opened to the surge tank 22 and the second three-way solenoid valve 78 is interposed, the auxiliary passage portion 72 is provided. Will be opened.

When the drive signal C ₁ is supplied from the control unit 100, the first three-way solenoid valve 67 makes the intake passage 12 and the diaphragm type negative pressure responsive valve 62 communicate with each other via the negative pressure introduction passage 65 to drive them. When the supply of the signal C ₁ is stopped, the intake passage 1 is passed through the negative pressure introduction passage 65.
2 and the diaphragm type negative pressure responsive valve 62 are closed, and the negative pressure introducing chamber 62a of the diaphragm type negative pressure responsive valve 62 is opened to the atmosphere. In addition, the second three-way solenoid valve 78 receives the drive signal C from the control unit 100.
_{When 2} is supplied, the negative pressure introducing passage 75 is brought into a communication state,
When the supply of the drive signal C ₂ is stopped, the negative pressure introducing passage 75
Is closed and the negative pressure introducing chamber 74a of the diaphragm type negative pressure responsive valve 74 is opened to the atmosphere.

The control unit 100 is provided with the above-mentioned detection signal S.
In addition to a, Sn and St, it is arranged in the exhaust passage 26,
O ₂ sensor 35 whose output characteristics change in the vicinity of the theoretical air-fuel ratio
Is supplied from the water temperature sensor 32 provided in the engine body 10, and further the detection signal Sw according to the engine cooling water temperature obtained from the water temperature sensor 32 provided in the engine body 10 and the position of the speed change lever 34 of the transmission (not shown) are detected. A detection signal Sr obtained from the shift position sensor 36 corresponding to the position of the shift lever 34, a detection signal Sc obtained from a clutch sensor 38 provided in association with the clutch pedal 37 and representing a stepped state of the clutch pedal 37, a brake pedal Another detection signal group Sx necessary for controlling the engine, which includes a detection signal Sb obtained from the brake switch 48 which is turned on or off when 47 is stepped on to a certain extent and a detection signal indicating the intake air temperature, is also provided. Supplied. The control unit 100 operates the fuel injection valve 2 based on the various detection signals and the detection signal group described above.
5 controls the amount of fuel injection, and controls the amount of valve opening in the flow rate adjusting valve 19;
Also, switching control of the second three-way solenoid valves 67 and 78 is performed to control the release of the evaporated fuel.

Then, the control unit 100 obtains from the throttle opening sensor 18 whether or not the operating state of the engine is in the idling state or is in the high load state in performing the various controls as described above. The determination is made based on the detected signal St. In that case, as shown in FIG. 3 described above, the level V of the detection signal St causes the accelerator pedal to be released and the throttle valve 16 to open due to a manufacturing error, an assembly error of the throttle opening sensor 18, or a secular change. Even in the state where the idling opening Th ₀ is taken, a level V ₁ ′ that takes a value larger by ΔV ₀ than the level (planned reference level) V ₀ that is a predetermined reference to be taken at that time is taken, for example. This level V ₀ ′ represents that the throttle valve 16 has an opening Th ₀ ′ that is slightly larger than the idling opening Th ₀ .

Therefore, the control unit 100, for example, that the engine is in the idling state, the level V of the detection signal St, the opening Th ₁ made slightly larger than the level V ₀ that corresponds to the idling opening degree Th ₀ If the determination is made by determining whether or not the level is equal to or lower than the corresponding level V ₁ , the opening degree Th of the throttle valve 16 is actually the idling opening degree Th ₀ , but the idling state is not set. Otherwise, there is a risk of making an erroneous decision. Similarly, it is determined whether or not the engine operating state is in a high load state, whether or not the level V of the detection signal St is higher than a predetermined reference level V ₀ by a predetermined level Vh or higher than a level V _2. If this is done, the level V of the detection signal St becomes greater than the level V ₂ when the opening Th of the throttle valve 16 is the opening Th ₂ ′ that actually represents a high load state. Since the level becomes V ₂ ′, the control unit 100 operates the throttle valve 16
There is a risk that the load Th may be erroneously determined to be in the high load state before the opening Th actually reaches the opening Th ₂ .

Therefore, the control unit 100 detects the detection signal S obtained from the shift position sensor 36 and the clutch sensor 38 in order to prevent the above-mentioned erroneous determination.
Based on r and Sc, it is detected that the position of the gear shift lever 34 is not in the neutral position and the clutch pedal 37 is not depressed, and the power transmission path from the engine to the wheels is in the connected state. Further, when it is detected that the brake pedal 47 is stepped on based on the detection signal Sb obtained from the brake switch 48, it is determined that the throttle valve 16 is in the idling opening state, and the detection at that time is made. Signal St
Count the number of uptakes. Then, the detection signal St is taken in until the number of times the detection signal St is taken in reaches a predetermined number X, the level V of the detection signal St at each time is integrated, and the sum ΣV is divided by the number of times X of the detection signal St taken in. Thus, the average level Vs of the detection signal St when the throttle valve 16 is in the idling opening state is calculated. Subsequently, the average level Vs calculated in place of the scheduled reference level V ₀ is stored in the built-in memory as the reference level Vs, and from the next operation, the average level Vs is calculated in the same manner as described above, and the average level Vs of the reference level Vs is calculated. You will be asked to update your memory.

The control unit 100 then detects the detection signal St.
Average level Vs stored in the internal memory from the level V of
Is corrected to reduce the level V of the detection signal St, and the opening Th of the throttle valve 16 corresponding to the corrected level V of the detection signal St is calculated. The calculated opening Th of the throttle valve 16 is used to determine the operating state of the engine when performing the above-described fuel injection amount control, intake air amount control, evaporated fuel release control, and the like.

As described above, the level V of the detection signal St is taken in when the brake pedal 47 is being depressed, so that the level V of the detection signal St when the throttle valve 16 is in the idling opening state. But,
It is surely taken in. Therefore, it is possible to avoid erroneously determining that the throttle valve 16 is in the idling opening state in a state in which the throttle pedal 16 is slightly opened by placing the foot on the accelerator pedal. Further, the average level Vs of the captured detection signal St is equal to the reference level Vs.
Is stored in the built-in memory as
Since the level V of the detection signal St is corrected based on s, the level V of the detection signal St is properly corrected.

Control unit 100 for performing control as described above
Is configured using, for example, a microcomputer, and an example of a program executed by the microcomputer in such a case will be described with reference to the flowcharts of FIGS. 4 and 5.

The flow chart shown in FIG. 4 shows a routine for correcting the detection signal St. After the routine is started, the detection signal St, Sr, Sc, Sb is fetched in the process 101, and the reference level calculation flag F is set in the subsequent decision 102. It is determined whether it is 1. The reference level calculation flag F is set to zero, for example, when the ignition key is turned off, and the average level Vs of the detection signal St when the throttle valve 16 is in the idling opening state is calculated and its memory is updated. If the reference level calculation flag F is not 1 in the decision 102, the decision 103 cuts off the power transmission path based on the detection signals Sr and Sc as described above. If it is determined that the power transmission path is in the connected state, the process proceeds to decision 104.

In the decision 104, it is determined based on the detection signal Sb whether or not the brake switch 48 is on, that is, whether or not the brake pedal 47 is depressed, and it is determined that the brake pedal 47 is depressed. If so, the accelerator pedal is opened and the throttle valve 16 is in the idling opening state. Therefore, in the subsequent process 105, 1 is added to the count number C to set it as a new count number C and the decision 107
Proceed to.

In the decision 107, it is judged whether or not the count number C is X times, and when it is judged that it is not X times,
In the process 108, the level V of the detection signal St fetched in the process 101 is added to the sum ΣV of the levels V of the detection signal St to return to the original, and when it is determined that the count number C is X times, By dividing the total sum ΣV by X times in the process 109, the detection signal S when the throttle valve 16 is in the idling opening Th ₀ state
The average level Vs of t is calculated, the average level Vs calculated in the subsequent process 110 is stored as the reference level Vs, and then the reference level calculation flag F is calculated in the process 111.
Set to 1 and return to the original.

On the other hand, when the decision 102 determines that the reference level calculation flag F is 1, the decision 103
When it is determined that the power transmission path is in the cut-off state at the time, and at the decision 104, the brake pedal 4
If it is determined that step 7 has not been stepped on, the process proceeds to process 112 without passing through processes 105 to 111, and the reference stored and updated in process 110 is calculated from the level V of the detection signal St captured in process 101. The level Vs is subtracted to set the level V of the corrected detection signal St, and in the subsequent process 113, the opening Th of the throttle valve 16 according to the level V of the corrected detection signal St is calculated and the process returns to the original. .

The flowchart shown in FIG. 5 shows the opening T of the throttle valve 16 calculated by the routine shown in FIG.
h is a routine for controlling the release of the evaporated fuel, which is used to judge the operating state of the engine.
The t, Sn, Sw, Sr and Sc and the detection signal group Sx are fetched, and it is determined in the subsequent decision 122 whether the engine cooling water temperature TW represented by the detection signal Sw is a predetermined value TW ₁ or more. This determination is for determining whether or not the engine warm-up is completed. When it is determined that the engine cooling water temperature TW is equal to or higher than the value TW ₁ , the process proceeds to decision 123, and based on the detection signal Sn. Then, it is determined whether the engine speed N is in a high rotation state equal to or higher than a predetermined rotation speed Nv. Decision 1
Opening Th of the throttle valve 16 calculated in the process 113 described above, it is judged whether or not the opening degree Th ₂ or more representing the high load state, is less than the opening degree Th ₂ representing the high load condition at 24 In case of decision 12
Go to 5.

In the decision 125, in order to determine whether or not the power transmission path from the engine to the drive wheels is in the cutoff state, whether or not the position of the shift lever 34 is in the neutral position based on the detection signal Sr, and Detection signal Sc
It is determined whether or not the clutch pedal 37 is in the depressed state, and if it is determined that the shift lever 34 is not in the neutral position and the clutch pedal 37 is not depressed, the power Since the transmission path is not in the cutoff state, it is determined in the subsequent decision 126 whether or not the opening Th of the throttle valve 16 is equal to or smaller than the opening Th ₁ . Then, the opening T of the throttle valve 16
When it is determined that h is not less than the opening Th _1, whether or not the feedback control (F / B) of the fuel supply amount is performed in the decision 127 is calculated in, for example, the fuel injection amount control. When it is determined that the feedback control is being performed based on the feedback correction value, the process proceeds to process 128 to introduce the evaporated fuel into the intake passage 12, and it is determined that the feedback control is not being performed. In this case, the decision 129 determines whether the intake air temperature TA is equal to or higher than the predetermined value TA ₁ based on one detection signal of the detection signal group Sx,
When it is determined that the intake air temperature TA is equal to or higher than the value TA ₁ , the process 128 is performed.

In the process 128, the drive signal C ₁ is supplied to the first three-way solenoid valve 67 to open the vaporized fuel discharge passage 60, and the drive signal to the second three-way solenoid valve 78 to close the auxiliary passage portion 72. The supply of C ₂ is stopped and the operation returns to the original state. As a result, when the intake negative pressure in the intake passage 12 is high, the evaporated fuel stored in the canister 50 is introduced into the intake passage 12 and burned in the combustion chamber 14.

On the other hand, in the decision 122, it is determined that the engine cooling water temperature TW is less than the value TW ₁ , when in the decision 125 it is determined that the power transmission path is in the cutoff state, and in the decision 129, the intake air temperature TA is the value. If it is determined that the value is less than TA ₁ , the evaporative fuel should not be introduced into the intake passage 12,
In the process 130, the supply of the drive signal C ₁ to the first three-way solenoid valve 67 is stopped and the supply of the drive signal C ₂ to the second three-way solenoid valve 78 is stopped, and the process returns to the original state. As a result, the evaporated fuel discharge passage 60 is closed by the diaphragm type negative pressure responsive valve 62, and the discharge of the evaporated fuel to the intake passage 12 is stopped.

If the decision 126 determines that the opening Th of the throttle valve 16 is equal to or smaller than the opening Th ₁ , the engine is in the idling state or the decelerating state, so that the evaporated fuel should not be introduced into the intake passage 12. In order to do so, the process 130 is executed in the same manner as described above and the process returns.

Further, when it is determined in the decisions 123 and 124 that the engine is in the high rotation speed or the high load state, in the process 131, the first three-way solenoid valve 6
Supplies a driving signal C ₁ to 7, back to the original by supplying a driving signal C ₂ to the second three-way solenoid valve 78. Thereby, in such a case, since the auxiliary passage portion 72 is opened, compared to the case where the auxiliary passage portion 72 is closed,
A larger amount of evaporated fuel will be introduced into the intake passage 12.

(Effect of the Invention) As is apparent from the above description, the engine throttle opening detecting device according to the present invention determines that the throttle valve is in the idling opening state when the braking means is in the operating state, and the opening degree is determined. Since the reference output is set and stored based on the detection output obtained from the output generating means, and the detection output obtained from the opening output generating means is corrected based on the reference output, the accelerator operating means is There is no erroneous determination that the throttle valve is in the idling opening state when it is operated to, and therefore it is possible to effectively prevent the correction of the detection output from becoming inappropriate.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram showing an engine throttle opening detection device according to the present invention in correspondence with the scope of the claims, and FIG. 2 is an example of an engine throttle opening detection device according to the present invention. FIG. 3 is a schematic configuration diagram shown together with the engine, FIG. 3 is a characteristic diagram used for explaining the operation of the example shown in FIG. 2, and FIGS. 4 and 5 are micro-controllers in the control unit in the example shown in FIG. It is a flow chart which shows an example of the program which such a microcomputer runs, when a computer is used. In the figure, 12 is an intake passage, 16 is a throttle valve, 18 is a throttle opening sensor, 30 is a rotation speed sensor, 50 is a canister, 60 is an evaporated fuel discharge passage, 65 is a negative pressure introduction passage, and 67 and 78 are first And a second three-way solenoid valve,
100 is a control unit.

Claims (1)

[Scope of utility model registration request] 1. A connection state of an opening degree output generating means for generating a detection output according to an opening degree of a throttle valve arranged in an engine mounted on a vehicle, and a power transmission path from the engine to a wheel in the vehicle. A power transmission state detecting means for detecting a power transmission state, a braking detection means for detecting an operating state of a braking means mounted on the vehicle, and a detection output indicating that the power transmission path is in a connection state from the power transmission state detecting means. Is obtained, and when the detection output indicating that the braking means is in the operating state is obtained from the braking detection means, the reference output is set based on the detection output obtained from the opening output generation means, Reference output setting means for storing the reference output, and correction of the detection output obtained from the opening output generating means based on the reference output stored by the reference output setting means An engine throttle opening degree detection device configured to include an output correction unit for performing the above.