JPS58210366A - Spark advance control device in gasoline engine - Google Patents

Abstract

PURPOSE:To make it possible to eliminate fluctuations in the idling speed of an engine, by setting, as a spark advance value, the value obtained by adding a predetermined spark advance value to the previous final compensated spark advance value, if a compensated spark advance value is greater than the above- mentioned value obtained by adding the predetermined spark advance value to the previous final compensated spark advance value. CONSTITUTION:At the step 405, a comparison is made between a compensated spark advance value thetaIDL and the value obtained by adding the previous final compensated spark advance value thetaOLD to a predetermined spark advance value DELTAtheta (mentioned as annealing amount). If thetaIDL>thetaOLD+DELTAtheta, the process is advanced to the step 406 for setting theta=thetaOLD+DELTAtheta. If IDL thetaIDL<thetaOLD+DELTAtheta, the process is advanced to the step 408 for setting theta=thetaIDL. Thereby, fluctuations in the idling speed may be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an advance angle control device for a gasoline engine.

Conventionally, the technology to keep the idle speed of a gasoline engine (hereinafter referred to as engine) constant is to monitor the engine speed and check for fluctuations in this speed! There is a method of advancing or retarding the ignition timing depending on the IC.

However, in this type of conventional technology, the increase or decrease in the idle rotation speed relative to a preset specified rotation speed is immediately corrected by the amount of change, so the fluctuation range of the idle rotation speed is limited. Although it is true that the amount is reduced, there is a drawback that engine vibration increases due to torque fluctuations caused by sudden changes in engine rotation that occur during the correction.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an advance angle control device for a gasoline engine that can reduce both fluctuations in engine idling speed and engine perturbation caused by correction. It is something.

Honwamei achieves the above objectives. Therefore, if the corrected lead angle value calculated by the calculation is larger than the preset predetermined lead angle value plus the previous final corrected lead angle value, the control unit adjusts the value of the corrected lead angle value. Regardless of the above, the present invention is characterized in that it has a function of controlling the lead angle value of the igniter by adding the previously final corrected lead angle value to the predetermined lead angle value.

Hereinafter, an example of a pigeon according to the present invention will be explained in detail with reference to the drawings.

First, in FIG. 1 showing the complete construction, reference numeral 1 denotes a gasoline engine, which is connected to an air cleaner 4 through an intake manifold and two boots 5. Further, the exhaust manifold 5 is connected to a three-way catalyst device 7 via an exhaust pipe 6.

A throttle valve 8 provided in the intake manifold 2 is provided with a throttle sensor 9 for detecting its opening degree, and the intake manifold 2 is also provided with a pressure sensor 10 for detecting the amount of intake air and a pressure sensor 10 for detecting the amount of intake air. Manifold 2
An injector 15 is provided for injecting water into the fuel cell.

11 is a sensor 02 installed in the exhaust manifold 5 to detect the oxygen concentration in the exhaust gas, and 12 is a water temperature sensor installed in the water jacket to detect the temperature of the cooling water of the engine 1.
is a conventional distributor that rotates once for every two revolutions of the enrift, and a crank angle signal generator 22 shown in FIG. 2 is installed in the housing of this distributor, which generates a crank angle signal every time the crankshaft rotates by a predetermined angle. . The crank angle signal generator It22 has a reference position sensor 22b that detects the reference position of the crank, and a crank angle sensor 225L that detects a predetermined rotation angle (30° in this example) of the crank.

In addition to the crank angle signal generator 1f22 that generates the crank angle signal, the distributor 16 has a built-in eveninger 16 that advances or retards the ignition timing according to a control signal from the control unit 14, which will be described later. are doing. Note that since this is already a well-known technique, its details will be omitted.

The aforementioned throttle sensor 9. Pressure sensor 10°02 sensor 11. Water temperature sensor 12 and distributor 1
A crank angle signal generator 22 (not shown) of No. 3 is connected to the input side of the control unit 140, and is connected to the input side of the control unit 140.
5 and an igniter 16 are connected to the output side of the control unit 14.

In addition, in this example, an intake temperature sensor, battery voltage sensor, starter sensor, 02 sensor, neutral switch sensor, heavy speed sensor, air conditioner switch sensor, and idle switch sensor are provided, but they are omitted in Fig. 1. .

Next, the control unit 14 will be explained based on FIG. 2.The throttle sensor 9. Pressure sensor 10, water temperature sensor 12. Intake air temperature sensor and battery voltage sensor are A
The crank angle sensor 22a and the reference position sensor 22 of the crank angle signal generator 22 are connected to the /D gomverter 17.
b, starter, 02sey+11. neutral switch. The vehicle speed sensor, air conditioner switch and idle switch are connected to Sky:/l-7 Ace 18. Further, the injector 15 and the igniter 16 are respectively connected to the output interface 21.

Control unit 14 (D internal h A/D
:I y, <-p 17. Input h interface 18
．． Central processing unit (hereinafter referred to as CPU) including a soft timer, free time counter, and conveyor register 19.
Memo including RAM20a-ROM20b! 720 Oh! and output interface 21. So.

These are each connected by bus fin BUS1.
There are 1.

Next, the operation of the control unit 14 will be explained based on the flowcharts shown in FIGS. 3 to 6.

FIG. 3 shows part of the main processing routine. When the engine's ibnirasilane switch is turned on, the CP
U19 first executes initial processing and the like, and thereafter repeats and executes main processing, a part of which is shown in steps 101 to 106.

In step 101, memory 20 (7) RAM 2
Clear Q a and read the various data from each sensor. Next, in step 102, the required time required for the engine crank to rotate 180 degrees, which is calculated by the interrupt processing routine shown in FIG. 4 and stored in the RAM 20a, is taken in to calculate the rotational speed NH.

The crank angle interrupt processing routine shown in the f4r4 diagram is executed every 30'' of crank angle, and is executed by the pulse applied from the crank angle sensor 30JL every 30'' of crank angle, so that the engine crank rotates 180 degrees. The time required for this is calculated based on the difference between the values of a free run counter (not shown) built into the CPU 19 at the time of the previous interrupt and the time of the current interrupt.

In the next step, step 103, the data Q related to the intake air pressure, which is sent from the pressure sensor 10 via the A/D converter 17 and stored in the RAM 20&, and the rotation speed calculated in step 102. The basic injection amount of the injector 15 is determined by calculating Q/NI from the data Nl.

In step 104, a basic advance angle value θBl is determined from the data NE regarding the rotational speed using a basic advance angle map. R
A basic advance angle map for Q/NI and NE is stored in advance in the OM 20a, and in step 104, θBSE is determined using a branch interpolation calculation or the like. Note that this basic advance angle value θBSE is, in principle, kept at a constant value when the vehicle is idling, but is changed when, for example, the air conditioner is used or the accelerator is stepped on. It is. Therefore, it cannot be changed due to uneven rotation of the engine during idling.

Next, in step 105, the final advance value θFIN is calculated, and this process is performed according to the flowchart shown in FIG. 'That is, step 401
Now, the basic advance angle amount θBS obtained in step 104 is
K is taken in, and then, in step 402, it is determined whether the rotation of the engine 1 (not shown) is in an idle state. If this is determined to be "NO", that is, if the engine 1 is not in an idle state, there is no need for advance angle correction, so the final corrected advance angle value θ is set to 0 in step 407, and the process then proceeds to step 409.

On the other hand, if “Yes” is determined in step 402,
That is, if engine 1 is idle, step 40
Step 3 proceeds to find the difference ΔNB between the idle speed NF set in advance in the ROM7QbK and the engine idle speed NK found in step 102, and in the next step 404, the difference ΔNB is calculated using the corrected advance angle map. This Δ
From Nl, L is determined from the corrected advance angle value θ. A corrected lead angle map for ΔNF as shown in FIG. 7 is stored in advance in the ROM 2Qb, and a corrected lead angle value θIDL is determined based on this map.

Next, in step 405, the corrected advance angle value θIDL,
A comparison is made with the previous final complement H""e OL D which was obtained when this flowchart was carried out last time, plus a predetermined lead angle value △θ (so-called sluggish amount), and θIDL)OOLD+△ In the case of θ, that is, if the correction ant is large, the process advances to step 406 and θ=
Assuming that θOLD is ten people θ, the end correction advance angle value θ is set to θOLD+Δθ regardless of the magnitude of ΔNE.

If the comparison is θILD<θOLD+Δθ, the process proceeds to step 408, where the nine quasi-angular value θ; θIDL is set corresponding to the magnitude IfC of NE.

In this way, t (steps 405, 406, and 408 compare the corrected advance value θIDL and the previous final correction value θOLD, and when the change exceeds the predetermined advance value Δθ, 11-
j. Since the correction value is too large, only 〇 is corrected to the predetermined lead angle value (that is, to oOLD + 80), and when the amount of change in the corrected lead angle value θIDL is not equal to the predetermined lead angle value Δθ, the change is made. Since the amount is not so large, the corrected advance angle value θI
LD is directly used as the final corrected advance angle value θ. Note that the predetermined advance angle value △θ is normally 0.26CA maximum 2 in this example.
6CA.

Then, in step 409, the final corrected lead angle value θ obtained in this way is added to the basic lead angle value θBF3EK, which is set as the joint lead angle value θFIN, and in step 410, the value of the previous intermediate longitudinal correction value θOLD is added to the final corrected lead angle value θBF3EK. After converting to the value of the angle value θ,
Proceed to step 411. Step X7 sets the off time of the igniter 16 corresponding to the book final advance angle value θF'IN, that is, the time at which ignition is to be performed, in a conveyor register (not shown) in the CPU 19. That is, multiple ignition timing adjustments are made depending on whether the set time is long or short.

The soft timer, which matches the time set in the conveyor register, is configured to be started just in case when the crank and corner interrupts shown in Figure 4 are executed. Therefore, when the time set in the conveyor register comes after a predetermined period of time has passed since the execution of crank angle Jll input, the time coincidence interrupt shown in Fig. 5 is executed and the igniter 160 is ignited in step 601. The signal is reversed from on to off. That is, this stops the energization to the ignition coil (not shown) and generates an ignition spark from the ignition plug 26. However, this time coincidence interrupt is an interrupt for the injection instruction of the injector 15. This is used as a routine, but since it is already a known technique, its explanation will be omitted.

After executing step 411, the flowchart returns to the main processing routine shown in FIG. 3 and repeats the same processing.

In this way, in this embodiment, when the engine idle speed NF shown in FIG. 8 fluctuates from the preset target idle speed NF', the advance angle value is corrected by the amount of correction to immediately correct this. As shown by the broken line in Fig. 8, the lead angle value is controlled by performing so-called lead angle smoothing by setting the upper limit of the correction amount in - times of correction. There is. For this reason, θF work H in Fig. 8
As shown in the figure, even when the amount of fluctuation in engine speed is large, the upper limit of the amount of correction at one time is 80 (0.2° CA in this example).
As a result, sudden changes in engine rotation are eliminated and sudden torque fluctuations are eliminated, making it possible to prevent engine vibrations from occurring. Moreover, although the upper limit of the correction amount per time is 80 (0.26 CA in this example), this correction is performed every engine cycle (2 Franz revolutions), so the correction advance angle for fluctuations in idle speed is The followability of values is also quite consistent and sufficient in actual use. (For example, when the idle rotation speed is 600 rl) and the advance angle correction amount per cycle is set to 0.21 CA, the time required to correct 2@CA may be 1 second. ) In the above embodiments, only the case where the ignition timing is advanced has been explained, but the case where the ignition timing is retarded is as follows.

The flowchart shown in FIG. 10 corresponds to the flowchart shown in FIG. 6, and steps 505 and 506
They all have the same structure except for the content.

That is, in step 505, the corrected advance angle value θID
L is compared with the value obtained by subtracting a predetermined lead angle value △θ (so-called sluggish amount) from the previous final correction value θOLD obtained when this flowchart was executed last time, and θIDL (θ0LD - 80 In other words, if the correction amount is small, the process advances to step 506 and θ=θ0LD-
The final correction value θ is set as Δθ regardless of the magnitude of ΔNK. Also, the above comparison is θ
IDL) θ0LD−Δθ, step 508
Proceed to the advance angle value θ; θI corresponding to the magnitude of ΔNK.
DL. Therefore, as shown in θFIN in Fig. 10, when the amount of fluctuation in engine speed is large, the upper limit value of the correction amount per torque is △θ (0.2” CA in this example), so sudden changes in engine speed Since this eliminates sudden torque fluctuations, it is possible to prevent the occurrence of engine perturbation.Furthermore, although the upper limit of the amount of correction at one time is Δθ (0.26 CA in this example), this Since the correction is performed every engine cycle (two crank revolutions), the follow-up of the corrected advance angle value to fluctuations in the idle speed is sufficient enough to cause no problems in actual use. Since the action and effect are the same as those described above, the explanation thereof will be omitted.

That is, the present invention is based on t'11 described in the claims.
This configuration has an excellent feature in that it is possible to eliminate fluctuations in engine speed, that is, fluctuations in idle speed, without increasing engine vibration in a gasoline engine. Therefore, since the idle speed can be set low, it also has a desirable feature that the carrying cost is naturally improved.

It should be noted that, as a matter of course, the control unit may be configured to have both #81 functions of advancing and retarding injection, or may be configured to have only one of them. .

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and Fig. h'-1 is an explanatory diagram showing the overall configuration of the gasoline engine including the advance angle control device, Fig. 2 is a block diagram mainly showing the control unit, and Fig. Fig. 3 is a flowchart showing the main routine program, Fig. 4 is a flowchart showing the crank angle interrupt processing routine, Fig. 5 is a flowchart showing the time coincidence interrupt processing routine, and Fig. 6 is a flowchart showing the advance angle interrupt processing routine. FIG. 7 is an explanatory diagram showing a corrected advance angle map, and FIG. 8 is an explanation diagram showing a comparison between conventional control and control according to this example. FIG. 9 is a flowchart showing a program for calculating the final advance angle value during retard angle control, and FIG. 10 is an explanatory diagram showing a comparison between conventional control and control according to this example. 1... Gasoline engine 9... Throttle sensor 10... Pressure sensor 14... Control unit 16... Igniter 22...
Crank angle signal generator product Jun Hitoshi Tamaki, Toyota Motor Corporation representative Patent attorney Oka 1) Hidehiko $311 11114 Figure 5 tsa! I Four rules to determine main v) 3-8 Figure 110 II em Warp to main

Claims (1)

[Scope of Claims] A crank angle signal generating device that generates a crank angle signal every time the crankshaft of a gasoline engine rotates by a predetermined angle;
An igniter that has the function of varying the ignition timing and a pressure sensor that detects the amount of intake air. The rotation period of the gasoline engine, the basic advance value of the igniter, and the rotation period of the gasoline engine are set in advance based on information from each sensor such as a throttle sensor that detects the throttle opening, the crank angle signal generator, and each of the sensors. A control unit that calculates a correction lead angle value to correct the fluctuation to a predetermined period when it fluctuates from a predetermined period. The advance angle control device for a gasoline engine that has a predetermined advance angle, wherein the control unit adjusts the corrected advance angle value obtained by calculation to a predetermined advance angle value set in advance. A function of controlling the lead angle value of the igniter by adding the previous final corrected lead angle value to the predetermined lead angle value, regardless of the value of the corrected lead angle value, if the value is larger than the value added. An advance angle control device for an internal combustion engine, comprising: