JPH03225027A - Controller of internal combustion engine with swirl adjustment means - Google Patents

Abstract

PURPOSE:To improve startability at a low temperature starting condition by calculating a compensation coefficient from a temperature of cooling water in consideration of a start time so as to perform switching of compensation, when an adjustment of swirl in air flow is compensated by means of respective compensation coefficients at the opening and closing time. CONSTITUTION:Intake valves 16a, 16b, and exhaust valves 18a, 18b ar provided in a cylinder bore 12. A swirl control valve 32 is arranged in an intake port 12b. When the swirl control valve 32 is closed, air is sucked only from an intake port 12a so as to form the swirl. The swirl control valve 32 is controlled by a negative pressure delay valve 42 and a solenoid 3 direction switching valve 44. The solenoid valve 44 is controlled by a control circuit 50 which receives input signals from an intake pressure sensor 52, crank angle sensors 54, 56, an air-fuel ratio sensor 58, a throttle sensor 59, and a cooling water temperature detector 62, so that the swirl may be generated so as to improve startability at a low temperature starting condition, even in the case when difference between the atmospheric pressure and an intake pressure is small and a swirl adjustment means in its is opening condition.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an internal combustion engine control device equipped with a swirl adjustment means, and more particularly to an internal combustion engine control device equipped with a swirl adjustment means that improves startability when starting an internal combustion engine, particularly when starting at a low temperature. The present invention relates to an internal combustion engine control device.

[Prior Art] A lean combustion method that improves fuel efficiency by controlling the ratio of air and fuel supplied to an internal combustion engine, that is, the air-fuel ratio, to the lean side, and at the same time reduces the amount of nitrogen oxides emitted from the internal combustion engine. In a control device for an internal combustion engine that employs a installed immediately before.

In such an internal combustion engine with a swirl adjustment means,
Generally, a control device for controlling an internal combustion engine has an operating state determining means, and the swirl adjusting means is controlled by the output of this determining means.

On the other hand, the flow rate of the air-fuel mixture supplied to the internal combustion engine is also controlled by a control device, but accurate evaluation of the mass flow rate of intake air is important not only to maintain fuel efficiency and suppress the amount of nitrogen oxides emitted, but also to improve drivability. It is important for the improvement of

For this purpose, a method is used in which the intake air temperature and intake pipe pressure are measured, and based on these measured values, the measured value of the intake air volumetric flow rate is corrected, or a method is further corrected by taking into account the rotational speed of the internal combustion engine. (For example, Japanese Patent Application Laid-Open No. 62-153
No. 539 "Fuel injection amount control method for internal combustion engine").

However, since the swirl adjustment means is installed just before the cylinder intake port, the thermal state of the internal combustion engine changes when the swirl adjustment means is opened and closed, and the above correction alone is insufficient, leading to worsening of fuel efficiency and It is known that this causes an increase in the amount of nitrogen oxides exhausted and a deterioration of drivability.In order to solve this problem, the swirl adjustment means is open and
A control device has been proposed that switches the correction value when the engine is closed (Japanese Patent Application Laid-Open No. 1-159439, “Control Device for Internal Combustion Engine”).

[Problems to be Solved by the Invention] However, during internal combustion slight start operation, the swirl adjustment means is closed in order to generate swirl and improve combustion performance, but the swirl adjustment means uses the intake pipe as its driving source. It is common to use the differential pressure between pressure and atmospheric pressure, and since the intake pipe pressure is approximately equal to atmospheric pressure during internal combustion slight start operation, a closing control signal is output from the operating state determining means to the swirl adjusting means. Even if the swirl adjustment means is maintained in the open state, the swirl adjustment means close control signal is output from the operation state determination means, so that it is difficult to calculate the mass flow rate of intake air. The correction coefficient when the swirl adjustment means is closed is used as the correction coefficient, and the air-fuel ratio of the air-fuel mixture is controlled to the lean side, further deteriorating startability, and especially when the atmospheric temperature is low, the start-up time becomes longer. .

Although it is conceivable to additionally provide means for detecting the actual open/closed state of the swirl adjusting means, it is not economical to use a detecting means with sufficient reliability.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide an internal combustion engine control device with a swirl adjustment means that has excellent startability even when the atmospheric temperature is low.

[Means for Solving the Problems] As shown in FIG. A swirl adjustment means B for creating a swirl in the air flow, a correction coefficient calculation means C when the adjustment means B is open, a correction coefficient calculation means C when the adjustment means B is closed, and a correction coefficient calculation means when the adjustment means B is open. In addition to the correction coefficient switching means E for switching between the means C and the correction coefficient calculation means when closed, and the correction coefficient calculation means F which calculates the intake air temperature correction coefficient using the correction coefficient when opened or the correction coefficient when closed. hand,
internal combustion engine starting determination means G; internal combustion engine cooling water temperature detection means H; temperature determination means I for determining that the output of the cooling water temperature detection means H is equal to or higher than a preset threshold; A ring tightening product calculating means J which has two inputs are the output of the start-time determining means G and the output of the temperature determining means I, and the output of the logical product calculating means J and the output of the operating state determining means A as two inputs. [Operation] The control device having the above configuration guides the cooling water temperature signal detected by the cooling water temperature detection means H to the temperature determination means I, and detects the cooling water of the internal combustion engine. It is determined whether the temperature is below a preset temperature or not, and in the case of a low temperature start state where the cooling water temperature is below a specified value, regardless of the command from the operating state determining means A to the swirl adjusting means B. The intake air temperature coefficient is calculated by the intake air temperature coefficient calculation means F based on the output of the adjusting means opening correction coefficient calculation means C.

On the other hand, when the low temperature starting state is not present, and after the starting is completed and the state shifts to a steady operating state, the correction value switching means E is switched in accordance with the command from the operating state determining means A to the swirl adjusting means B, and the correction coefficient when the adjusting means is closed is calculated. The intake air temperature coefficient is calculated by the intake air temperature coefficient calculation means F based on the output of the means C or the adjusting means closed correction coefficient calculation means.

[Example] In FIG. 2, 10 is a cylinder bronze, 12 is a cylinder pore, 12a, 12b is an intake port, 14a, 14
b is an exhaust boat, 16a and 16b are intake ports 1
Two intake valves 2a, 12b and two exhaust valves 18a, 18b for the exhaust boat represent a so-called four-valve internal combustion engine. The first intake port 12a is a helical type, and is configured to have a shape convenient for forming an intake swirl. The second intake port 12b is of a straight type. The intake ports 12a and 12b are the intake pipes 20
, are connected to the throttle body 23 via the surge tank 22. An injector 26 is installed in the intake pipe 20 close to the intake ports 12a, 12b of each cylinder. The exhaust bows 14a, 14b are connected to an exhaust manifold 28. The distributor is represented by 30.

A butterfly-shaped swirl control valve 32 constituting the swirl adjustment means B is installed in the straight-shaped intake port 12b.

When the swirl control valve 32 is in the closed state, air is taken in only from the helical intake port 12a and a swirl is formed.

When the swirl control valve 32 is in the open state, air is taken in from the two intake ports 12a and 12b, and the swirl is eliminated.

A lever 34 is attached to the valve shaft of the swirl control valve 32 of each cylinder, and this lever 34 is connected to a negative pressure actuator 38 via a rod 36. Negative pressure actuator 3
8 is composed of a diaphragm 40 and a spring 41. When no negative pressure is applied to the diaphragm, the force of the spring 41 keeps the swirl control valve 32 open.

When negative pressure is applied to the diaphragm 40, the diaphragm 40 is attracted against the spring 41, and the swirl control valve 32 closes the intake port 1-12b. The diaphragm 40 is connected to the negative pressure outlet port 22a of the surge tank 22 via a negative pressure delay valve 42, an electromagnetic three-way switching valve 44, and a negative pressure holding check valve 46. The negative pressure delay valve 42 is constructed by arranging an orifice 42a and a check valve 42b in parallel, and appropriately controls the atmospheric pressure release speed of the actuator 420 to adjust the opening speed of the swirl control valve 32. Also, the check valve 46 is for maintaining the negative pressure applied to the diaphragm 4o. The electromagnetic three-way switching valve 44 includes three boats 44a, 44b, and 44c. In the non-energized state, the boats 44a and 44b are in communication, and the diaphragm 40 is connected to the negative pressure outlet port 22a, and in the energized state, the boats 44a and 44b are in communication. In this state, the boats 44a and 44c are in communication, and the actuator 42 is exposed to the atmosphere via the filter 48. The swirl control valve 32 is driven by an electromagnetic three-way switching valve 44 that is controlled by a control circuit 500 command number.

The control circuit 50 is composed of, for example, a microcomputer system, and has a function of controlling the electromagnetic three-way switching valve 44 according to the present invention.

The intake pipe pressure sensor 52 is installed in the surge tank 22 and generates an electrical signal proportional to the intake pipe pressure PM.

Crank angle sensor 54.56 is distributor 3
0, and is used to detect the internal combustion engine rotation speed NE and the reference position W (for example, top dead center) of the internal combustion engine cycle.

Further, an air-fuel ratio sensor 58 is provided to detect the air-fuel ratio of the exhaust gas, and a throttle sensor 59 is provided to detect the opening degree of the throttle valve 24.

Furthermore, a temperature detector 62 that outputs an electrical output proportional to the temperature of the cooling water is installed in the water jacket 60 for circulating cooling water for cooling the internal combustion engine. Note that the temperature detector 62 constitutes a cooling water detection means H.

FIG. 3 is a flowchart for explaining a method of controlling the swirl control valve 32 according to the present invention.

Fig. 4 is a graph for determining the base intake air temperature correction coefficient when converting the volumetric flow rate into the mass flow rate.The vertical axis is the base intake air temperature correction coefficient FTHAO1, the horizontal axis is the intake air temperature, and the curve 0 is Curve C is used when the swirl control valve 32 is open, and curve C is used when the swirl control valve 32 is closed.

When the internal combustion engine is started, the routine shown in FIG. 3 is started, and first the state of the start flag X is determined (step 101). is set, so the intake pipe pressure PM is next determined (step 102). Here, the differential pressure between atmospheric pressure PA and intake pipe pressure PM is set to a predetermined pressure setting value ΔPS (for example, −220
mmHg). Here, the atmospheric pressure PA can be detected by known means, such as by substituting the intake pipe pressure immediately before starting. Immediately after starting the internal combustion engine, the intake pipe pressure is substantially equal to atmospheric pressure, and the differential pressure between the atmospheric pressure PA and the intake pipe pressure is smaller than the set value ΔPS, so the actuator 38 is driven to close the swirl control valve. Can not. Incidentally, step 101 and step 102 constitute a starting determination means G. Next, the internal combustion engine cooling water temperature TH
C is a predetermined temperature set value TSET (for example, 0℃
) is higher than that (step 103). Note that step 103 constitutes temperature determination means (2). In the flowchart shown in FIG. 3, the fact that the start-up determining means G and the temperature determining means I are connected in series is equivalent to calculating the logical product of the outputs of the two means, and the logical product calculating means , 1 constitutes.

Therefore, when the internal combustion engine is started, that is, when the start flag If the THC is lower than the set value TSET, the base intake air temperature correction coefficient FTHAO is calculated from the intake air temperature THA using the curve O in FIG. 4, regardless of the output of the operating state determining means A (step 106).
), and step 106 constitutes adjustment means opening correction value calculation means C.

In addition, if the cooling water temperature THC is in a high-temperature starting state equal to or higher than the set value, a close command is output to the swirl control valve 32 (referred to as SCV) in another routine (not shown) constituting the operating state determining means A. It is determined whether or not there is one (step 105). The operating state determining means A is the swirl control valve 32
When the closing command is not outputted, the base intake air temperature correction coefficient FTHAO is similarly calculated using curve 0 (step 106).

When the operating state determining means A outputs a close command to the swirl control valve 32, the base intake air temperature correction coefficient FTHAO is calculated using the curve C in FIG. 4 (step 107).
)do. Note that step 107 constitutes a correction coefficient calculating means when the adjustment means is closed.

In the flowchart shown in FIG. 3, when one of step 103 and step 105 is "No", step 106 is executed, which constitutes the logical sum operation means, K, and correction coefficient switching means E. do.

Then, from the internal combustion engine rotational speed, the internal combustion engine rotational speed correction coefficient K
THANE is calculated (step 108), an intake pipe pressure correction coefficient KTHAPM is calculated (step 109), and an intake air temperature correction coefficient is calculated based on the correction coefficients calculated above. The internal combustion engine speed correction coefficient KTHANE is a coefficient for correcting changes in intake air temperature due to the influence of engine speed, and the intake pipe pressure correction coefficient KTHAPM is a coefficient for correcting changes in intake air temperature due to the effect of intake pipe pressure. be. In this embodiment, only the base intake air temperature correction coefficient FTHAO is used depending on whether the swirl adjustment means is closed or opened.
In order to perform more accurate intake air temperature correction, the internal combustion engine rotational speed correction coefficient KTHANE and the intake pipe pressure correction coefficient KTHAPM may also be used depending on whether the swirl adjustment means is closed or opened. Figure 5 shows the internal combustion engine speed correction coefficient of 1.
This is a graph showing an example, and the rotation speed correction coefficient KTHAN is applied to the joint shaft.
E, the rotational speed NE is plotted on the horizontal axis, curve O is used when the swirl control valve 32 is open, and curve C is used when the swirl control valve 32 is closed.

Steps 10B to 110 constitute intake air temperature correction coefficient calculation means F.

Also, the differential pressure between atmospheric pressure PA and intake pipe pressure PM is the set value ΔPS.
If it is larger (step 102), it is assumed that the internal combustion engine has completed starting and entered a steady operating state, and the start flag X is reset (step 104). Thereafter, while the internal combustion engine is operating, the start flag X will not be in the cent state (step).

101), a curve of the Haese intake air temperature correction coefficient is selected in accordance with the determination of the control method for the swirl control valve 32 in the operating state determining means A (step 105).

That is, when the mass flow rate is calculated using the output of the adjusting means opening correction coefficient calculating means C, the air-fuel ratio is set to the rich side,
When the mass flow rate is calculated using the adjustment means closed correction coefficient calculation means, the air-fuel ratio is set to the lean side.

[Effects of the Invention] As described above, according to the present invention, in order to generate swirl and improve combustibility, even though the operating state determining means outputs a close command to the swirl adjusting means, Even if the swirl adjustment means is actually in the open state because the differential pressure between atmospheric pressure and intake pressure is not higher than the specified value, swirl This is possible without additionally installing means for detecting the actual open/closed state of the adjustment means.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the basic configuration of the present invention, FIG. 2 is a diagram showing the configuration of an internal combustion engine for implementing the present invention, and FIG. 3 is a flowchart for explaining the present invention in detail. FIG. 4 is a graph for determining a correction coefficient in the embodiment, and FIG. 5 is a graph for determining another correction coefficient in the embodiment. In the figure, 12a, 12b...intake boat, 14a, 14b...exhaust port, 16a, 16b
- Intake valve, 18a, 18b... Exhaust valve, 32... Swirl control valve, 38... Actuator, 44... Solenoid three-way switching valve, 46... Check valve, 50... Control Circuit, 62...Cooling water temperature detector. Diagram Intake air temperature THA Engine speed NE

Claims (1)

[Claims] 1. A means for determining the operating state of an internal combustion engine (A), and generating a swirl in the air flow taken into the cylinder of the internal combustion engine controlled by the output of the operating state determining means (A). a swirl adjustment means (B) for the adjustment, a correction coefficient calculation means (C) when the adjustment means (B) is open, a correction coefficient calculation means (D) when the adjustment means (B) is closed, and a correction coefficient calculation means (D) when the adjustment means (B) is closed; Correction coefficient switching means (E) for switching between the correction coefficient calculation means (C) at the time of closing and the correction coefficient calculation means (D) at the time of closing.
and a swirl adjustment having an intake air temperature correction coefficient calculation means (F) for the fuel injection amount using the output of the correction coefficient calculation means (C) when the opening is performed or the output of the correction coefficient calculation means (D) when the closed time is used. An internal combustion engine control device with means, comprising: a start determination means (G) for the internal combustion engine; a cooling water temperature detection means (H) for the internal combustion engine; and an output of the cooling water temperature detection means (H). Temperature determination means (I) that determines whether the temperature is above a preset threshold; and the output of the start-up determination means (G) and the temperature determination means (I).
a logical product calculating means (J) having two inputs of the output of the logical product calculating means (J); and a logical sum calculating means having two inputs of the output of the logical product calculating means (J) and the output of the driving state determining means (A). (K
), and switches the correction coefficient switching means (E) according to the output of the logical sum operation means (K).