JP2742094B2 - Engine idle speed control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an idle speed control device that controls an engine speed to a target speed during idle operation of an engine.

2. Description of the Related Art Conventionally, as this type of idle speed control device, for example, as disclosed in JP-A-58-190572, a bypass passage for bypassing a throttle valve is provided in an intake passage, and the bypass passage is provided. A control valve is provided in the passage, and during an idle operation in which the throttle valve is closed (when the accelerator pedal is not depressed), if an external load is applied to the engine by turning on the air conditioner or the like, the engine is operated according to the external load. It is known that a target rotation speed is set and the opening of the control valve is adjusted so that the idle rotation speed of the engine becomes the target rotation speed to correct the intake air amount.

(Problems to be Solved by the Invention) When such an idle speed control device is provided in an engine to which an automatic transmission is connected, the transmission is shifted from a neutral range position to a drive range position during idling operation. When the shift is performed, a load is applied to the engine, so that the intake air amount is increased and corrected.

In this case, if the corrected air amount is set based on, for example, starting, the corrected air amount becomes excessively large at the time of deceleration when the engine receives the driving force from the transmission, and the engine speed is maintained high, and the feeling of deceleration is impaired.

Further, as described above, when an external load is applied to the engine from an auxiliary machine or the like and the target rotation speed of the engine is set high according to the external load, the transmission shifts from the neutral range position to the drive range position. When the intake air amount is increased and corrected in accordance with the shift, if the correction air amount is set based on a small external load, when a large external load is received, the correction air amount becomes insufficient and the rotation drops. When the correction air amount is set on the basis of the load, the correction air amount becomes excessive when a small external load is received, and a blow-up occurs. In this case, it is conceivable to previously set a plurality of correction air amounts of the intake air amount on the map according to the type of the external load, and control the correction air amount according to the map. Will increase.

The present invention has been made in view of such a point, and a purpose thereof is to obtain a load torque of an automatic transmission, and to correct an air amount according to a load from the transmission based on the load torque. It is to perform with high accuracy.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, a load torque of a transmission corresponding to a target rotation speed is obtained from a ratio between a turbine rotation speed of the transmission and a target rotation speed of an engine. That is, the control of the intake air flow rate is corrected according to the torque.

Specifically, as shown in FIG. 1, the solution taken by the present invention includes an automatic transmission 50 connected to an engine, an intake flow rate adjusting means 41 for adjusting an intake air amount, and an engine speed. The engine speed detecting means 37 to be detected and the output of the engine speed detecting means 37 are controlled to control the intake flow rate adjusting means 41 so that the engine speed becomes a target speed according to an external load acting on the engine. It is assumed that the engine idle speed control device includes the speed control means 42 that performs the control. Then, a turbine speed detecting means 34 for detecting the turbine speed of the transmission 50, an output of the turbine speed detecting means 34 and the speed control means 42 are received, and a ratio of the turbine speed to the target speed is received. The load torque of the transmission corresponding to the target rotational speed is determined from the above. When the load torque is small in accordance with this load torque, the rotational speed control means
It is assumed that a correction means 43 for correcting the control of the intake flow rate adjusting means 41 by the control means 42 in the decreasing direction is provided.

(Operation) With the configuration described above, in the present invention, the intake flow rate adjusting means 41 is controlled by the rotational speed control means 42, and the engine speed becomes the target speed according to the external load.

In this case, based on the target rotation speed set by the rotation speed control unit 42 and the turbine rotation speed detected by the turbine rotation speed detection unit 34, the load torque of the transmission 50 corresponding to the target rotation speed is determined by the correction unit 43. When the load torque is small in accordance with the load torque, the control of the intake flow rate adjusting means 41 by the rotation speed control means 42 is corrected so as to be in the decreasing direction. Air amount correction is performed with high accuracy.

That is, regardless of the magnitude of the external load, when the shift from the neutral range position to the drive range position is performed, the intake air amount correction without excess or deficiency, that is, the intake air amount correction according to the traveling state is performed, so that the engine Overcorrection of the intake air amount during deceleration is prevented, and a sufficient deceleration feeling can be obtained. In addition, when the target engine speed fluctuates according to the type of external load, the intake air amount correction is performed according to the fluctuation of the target engine speed, so that it is necessary to control the corrected air amount using a map. No setting man-hours are required.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows an engine provided with an idle speed control device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cylinder block, and 2 denotes a cylinder head disposed on the cylinder block 1. A cylinder 3 is formed by the cylinder block 1 and the cylinder head 2. Is slidably inserted into the cylinder 3
A combustion chamber 5 is formed above.

The cylinder head 2 is provided with an ignition plug 6 facing the combustion chamber 5. Reference numeral 7 denotes an ignition coil for generating a secondary voltage. Reference numeral 8 denotes a distributor which is provided to be driven by the engine output shaft and is connected to the ignition coil 7 and the ignition plug 6. The distributor 8 supplies a secondary voltage from the ignition coil 7 to the ignition plug 6. To distribute.

An intake passage 10 is connected to the combustion chamber 5.
The upstream end of 10 is open to the atmosphere via an air cleaner (not shown). An intake valve 11 is provided at an opening of the intake passage 10 to the combustion chamber 5, so that intake air is introduced into the combustion chamber 5 at a predetermined timing. The intake passage 10 is provided with a throttle valve 12 for adjusting the intake flow rate. Further, a bypass passage 13 that bypasses the throttle valve 12 is provided in the intake passage 10, and an ISC valve 14 is provided in the bypass passage 13.
Duty control is performed. This bypass passage 13 and ISC
The valve 14 functions as intake flow rate adjusting means 41 for adjusting the intake air flow rate. In addition, a sub-passage 17 is provided in the intake passage 10 in parallel with the bypass passage 13. The sub passage
17 includes a temperature-sensitive air valve 18 that operates according to the temperature of the engine cooling water, and a screw 19 that changes the passage area.
And are provided in parallel. Further, an injector 15 for injecting fuel into the intake air is provided at an end of the intake passage 10 on the combustion chamber side.
Is provided.

An exhaust passage 20 is connected to the combustion chamber 5.
The downstream end of 20 is open to the atmosphere. An exhaust valve 21 is provided at an opening of the exhaust passage 20 to the combustion chamber 5, and exhaust gas is extracted from the combustion chamber 5 at a predetermined timing. The exhaust passage 20 is provided with a catalyst 22 for purifying exhaust gas.

The above-mentioned engine has a well-known automatic
The transmission 50 is connected. The transmission 50 has N, P, L, S, D, and R range positions. Hereinafter, for convenience, each range position of N and P is referred to as N range,
Each range position of L, S, D, and R is called D range.

The operation of the ISC valve 14 and the injector 15 is controlled by a control unit 30.
An ignition signal is sent to the coil 7 at a predetermined timing.

Furthermore, 31 is a water temperature sensor for detecting the temperature of the engine cooling water, and 32 is an automatic transmission.
A D-range detection switch for detecting that the range position of the transmission 50 is in the D-range, an air conditioner operation switch 33 for an air conditioner (not shown), and an automatic transmission 50 for the automatic transmission 50, A turbine sensor as a turbine speed detecting means for detecting the turbine speed of the transmission 50,
35 is an oil temperature sensor for detecting the oil temperature of the transmission 50, 36 is a pressure sensor for detecting the pressure of the compressor of the air conditioner, 37 is a rotation speed sensor as engine speed detection means for detecting the engine speed. And
Output signals of these sensors 31 to 37 are input to the control unit 30.

Next, the control of the control unit 30 will be described with reference to the block diagram of FIG. In the figure, first, it calculates the output T _HW, the target rotational speed N _O of the engine from an output of the output and air conditioner operation switch 33 of the D-range detection switch 32 of the water temperature sensor 31 in block B _1. Further, it calculates the torque loss of the engine from the output T _HW and the target rotational speed N _O of the engine coolant temperature sensor 31 in the block B _2, the block
Output N _T of the turbine sensor 34 B _3, the output T _OIL of the oil temperature sensor
And it calculates a load torque of the transmission 50 corresponding the target speed N _O of the engine to the target rotational speed N _O, the load torque output from the air conditioner of the output P _AC and air conditioner operation switch 33 of the pressure sensor 36 in block B ₄ Calculate.

Then, the target rotation speed N _O and the output Ne of the rotation speed sensor 37 are determined.
Based on a deviation between computes a torque to be feedback correction in block B _5. Furthermore, the feedback correction torque, obtains the final torque plus torque loss of the engine, the load torque and air conditioning load torque of the transmission 50, from the final torque at block B _6, calculates the amount of supplied air in accordance with this I do.

On the other hand, calculates the air flow to be passed through the intake passage 10 from the output T _HW of the water temperature sensor 31 in block B _7, and enter the air flow rate to the block B ₈ value obtained by subtracting from the amount of supplied air as a correction air quantity In this block, the drive duty is obtained from the corrected air amount. Then, in block B _9, the ISC valve 14 is duty controlled based on the drive duty.

Next, control of the control unit 30 will be described with reference to the flowcharts of FIGS. In Figure 4, after the start, the subroutine of FIG. 5 in step S ₁ calculates a target rotational speed N _O of the engine. That is, the transmission 50 is D in step S ₂₁ of the subroutine
Determines whether the range, when in the D range is the N _OBD shown in Figure 8 at step S ₂₂ in N _OB, the N _OBN shown in Figure 8 at step S ₂₃ when in the N range _Set to N _OB .
Then, step when the air conditioner at step S ₂₄ it is determined whether it is turned on, is turned on
In S _25, and N _OB, among the target engine rotational speed N _OAC when air conditioning turned on, the process returns to whichever larger as the engine target revolution speed N _O. On the other hand, when the air conditioner is not turned on in step S _26, returns the N _OB as the engine target revolution speed N _O.

Then, the process returns to the flow of FIG. 4, a loss torque T _LOSS engine in step S _2, is calculated by _{T LOSS = T LOSSB × C LOSSW} . Where T _LOSSB is the engine water temperature
This is the torque loss of the engine at 80 degrees, and is a function of the target rotational speed N _O as shown in FIG. Also, C _LOSSW is the water temperature correction coefficient is a function of the output T _HW (temperature) of the water temperature sensor 31 as shown in Figure 10.

Next, the capacity coefficient K _P in Step _{S 3, "K P = K} PB · C KPW"
Ask by Here, K _PB is a capacity coefficient specific to the transmission 50 when the oil temperature of the transmission 50 is 100 degrees Celsius, and as shown in FIG. 11, the difference between the turbine speed _NT of the transmission 50 and the target speed N _O it is a function of the ratio N _T / N _{O. CKPW} is an oil temperature correction coefficient, which is a function of the oil temperature T _OIL of the transmission 50 as shown in FIG.

Then, determined by _{"T AT = K P · N} O 2" load torque T _AT transmission 50 corresponding to the target rotational speed N _O Step S _4. Moreover, to calculate the air conditioning load torque T _AC by the subroutine of FIG. 6 at step S _5. That is, whether or not air conditioner has been turned on in step S ₃₁ of the subroutine, the air conditioning load torque T _AC at step S ₃₂ when being turned on "T _AC = K _AC
・ P _AC "and returns. Here, K _A is a constant,
P _AC is the pressure of the compressor of the air conditioner. On the other hand, when the air conditioner is not turned on, step S
_33, the N _OB and engine target revolution speed N _O. Load torque T
Return _AC to “0” and return.

Next, returning to the flow of FIG. 4, calculates a feedback correction torque T _FB by the subroutine of Figure 7 in step S _6. That is, the feedback condition is determined whether a condition is satisfied in the step S ₄₁ of the subroutine, when it is satisfied, the feedback correction torque T in step S _42
FB is _calculated by “T _FB = T _FB + T _FBI ” and the process returns. Here, T _FBI is a correction amount of the correction torque. FIG. 13 shows a gain in feedback control. On the other hand, when the feedback condition is not satisfied, and then returns to "0" feedback correction torque T _FB at step S _43.

Furthermore, the return to the flow of FIG. 4, step S ₇ in the engine required torque T _TOTAL (final torque) "T _TOTAL =
Determined by _{T LOSS + T AT + T AC} + T FB ". Then, calculates the supply air amount Q _TOTAL in accordance with the required torque T _TOTAL.

Then, it calculates the air flow rate Q _MAIN should pass through the intake passage 10 at step S _9, the air flow rate Q _ISC should pass through the ISC valve 14 in step S _10, determined by _{"Q ISC = Q TOTAL -Q MAIN} " . Here, _QMAIN is the engine coolant temperature T as shown in FIG.
It is a function of _HW . Furthermore, the air flow rate Q in step S ₁₁
"D = D _B · C drive duty D of the ISC valve 14 in accordance with the _{ISC
Tcoil-C VB} determined by ". Then, at step S ₁₂ and outputs the drive duty D for driving the ISC valve 14. Here, D _B is a basic driving duty of the duty solenoid of the ISC valve 14 This is a value when the coil temperature is 80 degrees Celsius and the supply voltage is 14 V, and is a function of the air flow rate Q _ISC as shown in Fig. 15. C _TCOIL is a coil temperature correction coefficient, coil temperature (here substituted by the engine coolant temperature T _HW), as shown in FIG. is a function of. Moreover, C _VB is a voltage correction coefficient, the supply voltage V _B as shown in FIG. 17
Is a function of

In the above flow, step S _1, step S _2, at step S ₅ to S _12, the rotational speed control means for controlling the intake air flow adjusting means 41 so that the engine speed becomes a target rotational speed corresponding to the external load 42 Is composed. Also step
By S ₃ and step S _4, receives the output of the turbine speed detecting means (turbine sensor) 34 and a rotation speed control unit 42, a transmission 50 corresponding to the target rotational speed from the ratio between the turbine speed and the target rotational speed A correcting means 43 is provided for obtaining a load torque and correcting the control of the intake flow rate adjusting means 41 by the rotational speed control means 42 in the decreasing direction when the load torque is small in accordance with the load torque.

Therefore, in the above embodiment, the rotational speed control means
The intake flow rate adjusting means 41 is controlled by 42, and the engine speed becomes the target speed according to the external load by the air conditioner.

In this case, based on the target rotation speed set by the rotation speed control unit 42 and the turbine rotation speed detected by the turbine rotation speed detection unit (turbine sensor) 34, the correction unit 43 controls the transmission 50 corresponding to the target rotation speed. A load torque is obtained, and when the load torque is small in accordance with the load torque, the intake flow rate adjusting means by the rotation speed control means 42.
Since the control of 41 is corrected so as to be in the decreasing direction, the air amount correction according to the load from the transmission 50 is accurately performed.

That is, regardless of the magnitude of the external load, when the shift from the neutral range position to the drive range position is performed, the intake air amount correction without excess or deficiency, that is, the intake air amount correction according to the traveling state is performed, so that the engine Overcorrection of the intake air amount during deceleration is prevented, and a sufficient deceleration feeling can be obtained. In addition, when the target engine speed fluctuates according to the type of the external load, the above intake air amount correction can be performed according to the fluctuation of the target engine speed. There is no need, and the number of setting steps is reduced.

(Effect of the Invention) As described above, according to the engine idle speed control device of the present invention, the intake air flow rate is adjusted so that the engine speed becomes the target speed according to the external load, and the transmission is controlled. The load torque of the transmission corresponding to the target rotational speed was determined from the ratio of the turbine rotational speed of the turbine to the target rotational speed, and when the load torque was small in accordance with the load torque, the intake air flow rate was corrected to be reduced. When controlling the engine speed to the target speed according to the external load, the intake air amount correction according to the load from the transmission is accurately performed.
When the intake air amount is corrected according to the running condition and the intake air amount is overcorrected when the engine is decelerated, sufficient deceleration feeling is obtained and the target engine speed changes according to the external load. The correction of the intake air amount is performed in accordance with the fluctuation of the target rotation speed, and there is no need to control the correction air amount by using a map, and the number of setting steps is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 17 show an embodiment of the present invention, FIG. 2 is an overall schematic diagram, FIG. 3 is a block diagram for explaining the operation of the control unit, and FIGS. 4 to 7 are diagrams of the control unit. FIG. 8 is a flowchart illustrating the operation, FIG. 8 is a correlation diagram between the engine water temperature and the target rotation speed, FIG. 9 is a correlation diagram between the target rotation speed and the loss torque, and FIG. 10 is a correlation between the engine water temperature and the water temperature correction coefficient. FIG. 11, FIG. 11 is a correlation diagram of a capacity coefficient with respect to a ratio between a turbine rotation speed and a target rotation speed, FIG. 12 is a correlation diagram of a transmission oil temperature and an oil temperature correction coefficient, and FIG. 13 is a feedback correction gain. FIG. 14 is a characteristic diagram, and FIG.
FIG. 15 is a correlation diagram between the air flow to be passed through the ISC valve and the drive duty, FIG. 16 is a correlation diagram between the engine water temperature and the coil temperature correction coefficient, and FIG. 17 is a correlation diagram between the supply voltage and the voltage correction coefficient. is there. 34 Turbine sensor (turbine speed detecting means) 37 Speed sensor (engine speed detecting means) 41 Intake flow rate adjusting means 42 Speed control means 43 Correcting means 50 Transmission

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Sato 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Inside Mazda Co., Ltd. (56) References JP-A-61-132750 (JP, A) JP-A-62 -214240 (JP, A) JP-A-62-294746 (JP, A)

Claims (1)

(57) [Claims] An automatic transmission is connected to an engine, an intake flow rate adjusting means for adjusting an intake air flow rate, an engine speed detecting means for detecting an engine speed, and an output of the engine speed detecting means. An idle speed control device for the engine, the speed control device controlling the intake flow rate adjusting device such that the engine speed becomes a target speed according to an external load acting on the engine. A turbine rotation speed detecting means for detecting a turbine rotation speed, and a transmission corresponding to a target rotation speed based on a ratio between the turbine rotation speed and the target rotation speed, receiving outputs of the turbine rotation speed detection means and the rotation speed control means. The load torque is determined, and when the load torque is small in accordance with the load torque, the rotation speed is determined. A control unit for correcting the control of the intake air flow rate adjusting unit so as to decrease the intake flow rate adjusting unit in a decreasing direction.