JP2012013026A - Idle control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize idle speed immediately after starting in frosty weather at a sub-zero temperature, inhibit hunting of engine speed feedback control or eliminate it earlier, and reduce discomfort of an occupant caused by generation of fluctuated engine speed, in an idle control device of an internal combustion engine.SOLUTION: When water temperature at starting is higher than a set value (ST2) preset separately from warming-up determination and does not meet warming-up completion determination, engine speed (Ne) of the internal combustion engine (1) is higher than a determination speed which is less than the initial target speed (Ntgel) by a predetermined quantity, and the state that power generation quantity is more than the predetermined value continues for a predetermined period of time, a control means (20) increases and renews the initial target speed (Ntgel) each time by the predetermined quantity as a target speed which is calculated based on an electric load, thus the speed can be increased to the preset upper limit target speed (MX).

Description

  The present invention relates to an idle control device for an internal combustion engine, and more particularly to an idle control device for an internal combustion engine that controls the idling speed during warm-up immediately after startup.

  The internal combustion engine of the vehicle includes detection means for detecting an operation state including the water temperature, the rotation speed, and the electric load of the internal combustion engine, and matches the target rotation speed based on the operation state detected by each detection means. Some of them are provided with an idle control device that performs rotation speed feedback control for changing the intake air amount.

Japanese Patent No. 3254262 JP 2003-336532 A

The engine idle speed control device according to Patent Document 1 controls the amount of idle air at an optimum speed according to the magnitude of the sudden increase when the electrical load suddenly increases during idle operation.
The air amount control device for an internal combustion engine according to Patent Document 2 corrects the intake air amount to the internal combustion engine in accordance with the alternator load torque.

By the way, in the conventional idle control device for an internal combustion engine, when setting the target rotational speed, as shown in FIG. 9, the rotational speed is calculated from the water temperature which is the cooling water temperature of the internal combustion engine, and the generator ( The electric load is estimated from the power generation amount of the alternator), the rotation speed corresponding to this electric load is calculated, and the larger value of the calculated rotation speed is set as the final target rotation speed. For example, when the rotation speed calculated by the water temperature (80 ° C.) is 900 rpm and the rotation speed calculated by the electric load is 1100 rpm, the target rotation speed during idle operation is selected to be the larger value because 1100 rpm It becomes. Similarly, even when there are other target rotational speeds based on other parameters, the value with the larger rotational speed is selected as the target rotational speed.
Further, in setting the target rotational speed, the electric load and the shift range state are taken into consideration, as shown in FIG. 10, when the air conditioner (A / C) switch is on or the shift range switch is in the N range. While setting the target rotational speed (N1), other target rotational speeds (N2) are set under other conditions.

As shown in FIG. 11, the rotational speed of the internal combustion engine 1 is set at the time of rotational speed feedback (F / B) in order to set a target rotational speed corresponding to the power generation amount (work amount) of the generator in consideration of fuel consumption. In some cases, the number (Ne) is equal to or greater than the determined rotational speed (Ntgel−α), which is a predetermined amount (α) less than the initial target rotational speed (Ntgel), and the power generation amount (Dfr: duty value) is equal to or greater than the predetermined value (β). When continuing for the predetermined time (T2), as the priority 1, the value of the rotational speed obtained by increasing the initial target rotational speed (Ntgel) by a predetermined amount (Nadd1) and the lower limit target rotational speed (preliminarily set to a predetermined value) Select the smaller (min) of (MN) and set the target rotational speed.
Further, the rotation speed (Ne) of the internal combustion engine 1 is less than a determination rotation speed (Ntgel + γ) obtained by adding a predetermined amount (γ) to the initial target rotation speed (Ntgel), and the power generation amount (Dfr) is less than a predetermined value (δ). In the case where the predetermined time (T2) is continued, the priority number 2 is set as the priority order 2, and the value of the rotational speed obtained by reducing the initial target rotational speed (Ntgel) by a predetermined amount (Nadd2) and the upper limit set in advance to the predetermined value. The larger one (max) of the target rotational speed (MX) is selected and the target rotational speed is set. Under conditions other than the above, as priority 3, the larger one (Max) of the initial target rotational speed (Ntgel) and the upper limit target rotational speed (MX) is selected, and the target rotational speed is set.

However, when the cooling water is not flowing to the radiator with the thermostat closed, it may not be possible to determine whether or not the internal combustion engine is in the warm-up completion determination condition only with the water temperature. As a cause of the change, the intake system is cold, and there is a problem that the atomization of the injected fuel becomes worse and the combustion is not stabilized.
Further, if the battery temperature is 0 ° C. or higher, the battery is always charged, so that the generator is always under a certain load. However, changes in electrical loads such as headlights, wipers, and turn signals directly affect power generation characteristics, resulting in changes in torque. Under the condition where the temperature of the battery is 0 ° C. or lower (below freezing point), a phenomenon occurs in which the change in power generation characteristics occurs in a short time (cycle), and thus a predetermined amount of power generation cannot be measured within a predetermined time. The target rotational speed could not be set to increase.

  As described above, when it is not possible to determine the increase in the rotational speed due to the electrical load, the target rotational speed is calculated based on the water temperature as shown in FIG. However, in the rotational speed calculated from the water temperature, the FR value, which is the value of the FR terminal indicating the power generation state of the generator, is 99% (maximum), but the target rotational speed does not increase (in FIG. 12, G1 (time t2) , G2 (time t4), G3 (time t6)), when it is not possible to cope with the change in the power generation characteristics, at the location where the load of the generator is removed (in FIG. 12, S1 (time t1), S2 (time t3) , S3 (time t5), S4 (time t7)), and hunting of the rotational speed occurs. And although the FR value fluctuates as 80 to 100% as the load of the generator, since the changing period is short, the current control does not determine that the load of the generator is large. Since the target rotational speed cannot be increased and the rotational speed does not increase, there is a disadvantage that a phenomenon that the hunting of the rotational speed does not fit occurs.

Also, in the case of cold regions (environmental conditions below freezing point), after the internal combustion engine is started, the vehicle starts traveling immediately. After the vehicle travels, the thermostat is not opened and the internal combustion engine Under the condition that the water temperature, which is the cooling water temperature, has reached the set water temperature set for the warm-up completion determination, the idling speed is difficult to stabilize.
As described above, the reason why the idling engine speed is not stable is that the warm-up is determined only by the water temperature, but the temperature in the engine room is substantially the same as the outside air temperature, and the temperature in the engine room has not increased. The battery is difficult to warm, the battery cannot be charged under freezing conditions, so no current flows, and the vehicle that is mainly used in urban areas in cold regions cannot be charged under freezing conditions Due to factors such as the weakness of the battery and the difficulty in raising the temperature of the battery body due to the absence of current flow, there is no power supply to the battery (cannot be recharged) in cold regions. Because the generator directly compensates for changes in the blower, etc., the output characteristics of the generator change suddenly. For example setting a lower idle speed), the unstable, also idle speed by not stable, there is an inconvenience that discomfort to the driver. In other words, the electrical load (headlight, blower by air conditioner (A / C), etc.) increases, so the load generated by the generator increases, and the amount of power generated by the generator is secured in response to this increase in load. In order to increase the engine speed, the warm-up state is estimated only by the water temperature and the target engine speed is set. There is a disadvantage that the rotational speed is insufficient.

  Furthermore, in the above Patent Documents 1 and 2, it is disclosed that the intake air amount is increased with an increase in the electric load, but the state where the surplus power cannot be charged to the battery or the electric load is not determined to be large. Thus, the idling speed is not stable, the control of the idling air amount is insufficient, and improvement has been desired.

  Accordingly, an object of the present invention is to stabilize the idling engine speed immediately after start-up when the temperature is below freezing, to suppress and quickly eliminate the occurrence of hunting in the engine speed feedback control, and to generate engine speed fluctuations. An object of the present invention is to provide an idling control device for an internal combustion engine that can reduce discomfort given to the occupant.

  The present invention provides each detection means for detecting an operation state including the water temperature, the rotation speed, and the electric load of the internal combustion engine, and calculates one or more target rotation speeds based on the operation state detected by each detection means. And finally-an internal combustion engine provided with control means for performing rotational speed feedback control for setting one target rotational speed and changing the intake air amount so that the rotational speed of the internal combustion engine matches the final target rotational speed In the engine idle control device, a power generation amount detection means for detecting a power generation amount corresponding to an electric load applied to the internal combustion engine is provided, and the control means is based on a water temperature at start-up or a water temperature after a predetermined operation. On the other hand, the start-up water temperature is higher than a preset value provided separately from the warm-up determination, does not satisfy the warm-up completion determination, and the rotational speed of the internal combustion engine is the initial target rotational speed From When the predetermined number of revolutions that are less than the predetermined value and the power generation amount is greater than or equal to the predetermined value continues for a predetermined time, the initial target revolution is incremented and updated by a predetermined amount as the target revolution calculated based on the electrical load. It is possible to increase up to a set upper limit target rotational speed.

  The idle control device for an internal combustion engine according to the present invention can stabilize the idling engine speed immediately after start-up when it is cold below freezing point, and can suppress or eliminate the occurrence of hunting in the engine speed feedback control early. In addition, it is possible to reduce discomfort given to the occupant due to the occurrence of fluctuations in the rotational speed.

FIG. 1 is a system configuration diagram of an idle control device. Example 1 FIG. 2 is a block diagram of the idle control device. Example 1 FIG. 3 is an explanatory diagram showing an example of establishment / non-establishment of the warm-up completion determination. Example 1 FIG. 4 is an explanatory view showing another example of establishment / non- establishment of the warm-up completion determination. Example 1 FIG. 5 is an explanatory diagram showing the setting of each target rotational speed including the minimum target rotational speed. Example 1 FIG. 6 shows a case where the number of revolutions corresponding to the power generation amount (work amount) of the electric load of the generator is set in consideration of the fuel consumption correspondence, and the initial target revolution number is increased and updated by a predetermined amount and set in advance. It is explanatory drawing which sets each rotation speed in the case where it can increase to a target rotation speed. (Example 2) FIG. 7 is a block diagram of an idle control device having a specific electrical load switch. (Modification of Example 2) FIG. 8 is an explanatory diagram in the case of determining to prohibit perturbation. (Example 3) FIG. 9 is an explanatory diagram for setting a conventional target rotational speed. (Conventional example) FIG. 10 is an explanatory diagram for setting a target rotational speed by an electric load or the like in the prior art. (Conventional example) FIG. 11 is an explanatory diagram for setting a target rotational speed commensurate with the power generation amount (work amount) of the electric load of the generator in consideration of fuel consumption. (Conventional example) FIG. 12 is a time chart showing a conventional state of occurrence of hunting of the rotational speed. (Conventional example)

  The present invention stabilizes the idling engine speed immediately after start-up when it is cold below freezing point, suppresses or eliminates the occurrence of hunting in the engine speed feedback control, and gives the occupant by generating the engine speed fluctuation. The purpose of reducing discomfort is to set the target speed according to the electric load even when there is no large electric load over a long period of time during the warm-up in cold weather where the influence of the electric load is significant. It is realized.

1 to 5 show a first embodiment of the present invention, which is an invention according to claim 4. FIG.
In FIG. 1, reference numeral 1 denotes an internal combustion engine mounted on a vehicle, and 2 denotes a drive system (transmission) connected to the internal combustion engine 1. The internal combustion engine 1 is connected to the downstream end portion of the intake manifold 4 that forms the intake passage 3 in the intake system, and is connected to the upstream end portion of the exhaust manifold 6 that forms the exhaust passage 5 in the exhaust system. The downstream end of the intake pipe 9 is connected to the upstream end of the intake manifold 4 via a throttle body 8 having a throttle valve 7. An air cleaner 10 is connected to the upstream end of the intake pipe 9.
Further, the internal combustion engine 1 is provided with a generator (alternator) 11 and a radiator 14 for cooling the cooling water via the inlet pipe 12 and the outlet pulp 13, and in front of the inlet pipe 12. A thermostat 15 that opens and closes so as to adjust the flow rate of the cooling water to the radiator 14 at a location is provided.
The internal combustion engine 1 is provided with an idle control device 16.
The idle control device 16 includes a bypass air pipe 18 that forms a bypass passage 17 that bypasses the throttle valve 7 and communicates with the intake passage 3, and an idle air amount control valve (ISC) provided in the middle of the bypass air pipe 18. And a control means 20 connected to the idle air amount control valve 19 to control the air amount to the internal combustion engine 1 during idling.

As shown in FIG. 2, the control means 20 includes an ignition switch 21 and a rotation of the internal combustion engine 1 as detection means for detecting the operation state including the water temperature, the rotational speed, and the electric load of the internal combustion engine 1 on the input side. Crank angle detecting means 22 capable of detecting the number (Ne), throttle detecting means 23 for detecting the throttle opening, water temperature detecting means 24 for detecting the water temperature that is the cooling water temperature of the internal combustion engine 1, and the temperature of the intake air An intake air temperature detecting means 25 for detecting the intake air temperature, an electric load detecting means 26 for detecting an electric load such as a small lamp, an air conditioner switch 27 for turning on / off an air conditioner (air conditioner: A / C), and driving A shift range switch 28 for detecting the range of the system (transmission) 2 is in communication.
Further, on the output side, a fuel injection valve 29, an ignition coil 30, an idle air amount control valve 19, an air conditioner compressor clutch 31, and an automatic transmission controller 32 are connected to the control means 20.
The control means 20 includes a fuel injection control unit 33, an ignition timing control unit 34, an idle air amount control unit 35, an air conditioner control unit 36, an automatic transmission control signal unit 37, an electric load calculation unit 38, and a rotation. A number setting unit 39 and a warm-up completion determination unit 40 are provided.

  The control means 20 calculates one or more target rotational speeds based on the operating state detected by each of the detecting means and finally sets one target rotational speed so that the rotational speed of the internal combustion engine 1 is finally reached. Rotational speed feedback control is performed to change the intake air amount so as to match the target rotational speed. Here, the rotational speed and the target rotational speed of the internal combustion engine 1 are the rotational speed per unit and are synonymous with the rotational speed.

In the control means 20, the warm-up completion determination of the internal combustion engine 1 is performed.
In this warm-up completion determination, the water temperature reaches a certain temperature (set value used for the warm-up completion determination) (for example, 90 ° C.), the thermostat 15 is opened after a certain period of time, and the cooling water is supplied to the radiator 14. Is in a state of turning.
Specifically, as shown in FIG. 3, this warm-up completion determination is performed in the order of priority 1, as shown in FIG. 3, at the time of starting water temperature ≧ set value ST1 (° C.) WT ≧ set value TH1 (° C.), which is satisfied when any one of the conditions when a predetermined time T1 (sec) or more has elapsed is satisfied. 2 is not established.
Alternatively, as shown in FIG. 4, this warm-up completion determination is performed with priority 1 as the condition of the starting water temperature ≧ the set value ST1 (° C.), or even when the water temperature (WT) exits the stop mode even if the water temperature (WT) is WT. ≧ Conditions when a certain time T1 (sec) or more has passed since the set value TH1 (° C.) or the intake air temperature (AT) is AT ≧ set value TA1 (° C.) It is established when it is satisfied, but it is not established as priority 2 under other conditions.

In the first embodiment, as shown in FIG. 5, the control means 20 determines completion of warming-up of the internal combustion engine 1 based on the starting water temperature or the water temperature after a predetermined operation, while the starting water temperature is determined in advance. Internal combustion engine based on electric load when higher than set value (ST2) provided separately from set value (ST1) in warm-up determination and when warm-up completion determination is not satisfied (when warm-up completion determination is not satisfied) A minimum target rotational speed (NLow) of 1 is set, and this is set as a priority order 1.
The control means 20 sets the first target rotational speed (N1) higher than the minimum target rotational speed (NLow) as the priority order 2 when the air conditioner switch 27 is on or the shift range switch 28 is in the N range. On the other hand, under other conditions, the second target rotational speed (N2) higher than the first target rotational speed (N1) is set as the priority order 3. The first target rotational speed (N1) and the second target rotational speed (N2) are the same as the conventional one.
As described above, in the first embodiment, the rotational speed of the internal combustion engine 1 drops sharply by newly setting the lowest target rotational speed (NLow) lower than the conventional first target rotational speed (N1). And the driver's discomfort caused by it can be reduced.
Then, in relation to the invention according to claim 5, the control means 20 calculates the target rotational speed based on the water temperature, and the target rotational speed calculated based on the target rotational speed calculated based on the water temperature and the electric load. The final target rotational speed of the internal combustion engine 1 is selected from a plurality of target rotational speeds including the above.
As a result, a further optimum target rotational speed corresponding to the operating state of the internal combustion engine 1 can be set, and the idle rotational speed can be stabilized. In other words, the final target rotational speed is selected and set from a plurality of calculated target rotational speed candidates for each control cycle, and the target rotational speed that is higher is selected. Then, the final target rotational speed is determined by selecting from the target rotational speed calculated from the water temperature and the minimum target rotational speed (NLow) calculated from the electric load.
As a result, in the first embodiment, by monitoring the start-up water temperature, the warm-up completion determination, and the like, for example, it is determined that the specific condition (cold region) is set, and the target rotational speed is set to the generator. 11 is set to a target rotational speed corresponding to the load of 11 and the idle air amount control valve 19 is operated to control the idle air amount to the internal combustion engine 1, thereby increasing the rotational speed of the internal combustion engine 1 to thereby increase the idle rotational speed. Can be stabilized.

FIG. 6 shows Embodiment 2 of the present invention.
In the following embodiments, portions that perform the same functions as those in the first embodiment will be described with the same reference numerals.
The feature of the second embodiment is the invention according to claim 1 in the following points. As shown in FIG. 6, the control means 20 determines completion of warming-up of the internal combustion engine 1 based on the water temperature at the start or the water temperature after a predetermined operation, while the water temperature at the start is set in advance in the set value ( It is higher than a set value (ST2) provided separately from ST1), does not satisfy the warm-up completion determination (when the warm-up completion determination is not satisfied), and the rotational speed (Ne) of the internal combustion engine 1 is the initial target rotational speed. When the determined rotational speed (Ntgel−α) is greater than (Ntgel) by a predetermined amount (α) and the power generation amount (Dfr) is greater than or equal to a predetermined value (β), As the target rotational speed calculated based on the load, the initial target rotational speed (Ntgel) is increased and updated by a predetermined amount (Nadd0.5, Nadd1...), And can be increased to a preset upper limit target rotational speed (NX).

In other words, the control means 20 is configured so that, at the time of the rotation speed feedback (F / B), the water temperature at the start is higher than the set value (ST2) provided separately from the set value (ST1) in the warm-up determination in advance. Completion determination is not satisfied (when warm-up completion determination is not satisfied), and the rotation speed (Ne) of the internal combustion engine 1 is equal to or greater than a determination rotation speed (Ntgel−α) that is a predetermined amount (α) less than the initial target rotation speed (Ntgel). And when the power generation amount (Dfr) is equal to or greater than the predetermined value (β), when the predetermined time (T2) continues, the priority target rotation number (Ntgel) is set to the predetermined amount (Nadd0. 5) The smaller value (min) of the value of the increased rotational speed and the target rotational speed (Mset) set in advance to a predetermined value is selected to set the target rotational speed.
In this priority order 0.5, first, the starting water temperature is higher than a preset value (ST2) provided separately from the preset value (ST1) in the warm-up determination and does not satisfy the warm-up completion determination ( If the warm-up completion determination is not established, the environmental condition at the time of starting is determined, and then the determined rotational speed (Ntgel−) where the rotational speed (Ne) of the internal combustion engine 1 is a predetermined amount (α) less than the initial target rotational speed (Ntgel). When the actual rotational speed is lower than the rotational speed obtained by subtracting a certain rotational speed value from the target rotational speed calculated by the electric load by determining whether or not α) or more, the generator 11 The state where the rotational speed is low and unstable with respect to the load of the generator 11 is determined, and the load of the generator 11 is calculated continuously for a predetermined time (T2) when the power generation amount (Dfr) is equal to or greater than the predetermined value (β). In order to read the FR value and under these conditions In the temperature environment, when the rotational speed of the internal combustion engine 1 is lower than the stable rotational speed, the load of the generator 11 is determined, and the rotational speed is commensurate with the load (work load) of the generator 11. Raised in stages.

Further, the rotational speed (Ne) of the internal combustion engine 1 is equal to or greater than the determined rotational speed (Ntgel-α), which is a predetermined amount (α) less than the initial target rotational speed (Ntgel), and the power generation amount (Dfr) is equal to or greater than the predetermined value (β). In the case where the predetermined time (T2) continues, as the priority 1, the value of the rotational speed obtained by increasing the initial target rotational speed (Ntgel) by a predetermined amount (Nadd1) and the lower limit set in advance to the predetermined value The smaller one (min) of the target rotational speed (MN) is selected and the target rotational speed is set.
Further, the rotational speed (Ne) of the internal combustion engine 1 is less than a determination rotational speed (Ntgel + γ) obtained by adding a predetermined amount (γ) to the initial target rotational speed (Ntgel), and the power generation amount (Dfr) is less than a predetermined value (δ). In some cases, when continuing for a predetermined time (T2), as the priority 2, the value of the rotational speed obtained by reducing the initial target rotational speed (Ntgel) by a predetermined amount (Nadd2) and the upper limit target set in advance to a predetermined value. The larger one (max) of the number of revolutions (MX) is selected and the target number of revolutions is set.
Under the conditions other than the above, as priority 3, the larger one (max) of the initial target rotational speed (Ntgel) and the upper limit target rotational speed (MX) is selected and the target rotational speed is set.
In the second embodiment, the final target rotational speed is selected and set from a plurality of calculated target rotational speed candidates for each control cycle, and a higher target rotational speed is selected. That is, the final target rotational speed is selected by selecting from the target rotational speed calculated from the water temperature and the target rotational speed calculated from the electric load.

The target rotational speed is updated so that the initial target rotational speed (Ntgel) is increased / decreased by a predetermined amount (Nadd0.5), a predetermined amount (Nadd1), and a predetermined amount (Nadd2) every control cycle. For example, while the condition of the priority order 0.5 is satisfied, the target rotational speed is increased from the initial target rotational speed (Ntgel) by a predetermined amount (Nadd0.5) and repeatedly increased by this predetermined amount (Nadd0.5). When the target rotational speed during the calculation exceeds the set target rotational speed (Mset) and thereafter, the target rotational speed is set to the set target rotational speed (Mset). Thereby, a drastic change mitigation process is performed. In this case, the target rotational speed (Mset) is a target rotational speed set to a predetermined value in advance, the lower limit target rotational speed (MN) is a lower limit guard value for the target rotational speed, and the upper limit target rotational speed (MX) is the target rotational speed. The upper guard value of the number.
Then, when the control is continued under the same priority order, the target rotational speed (Mset), the lower limit target rotational speed (MN), or the upper limit target rotational speed (MX) is converged. It will be. If the condition is not satisfied and the priority is shifted to a lower priority condition, the target rotational speed (Mset), the lower limit target rotational speed (MN), or the upper limit target rotational speed (MX) should not be converged. There is also. It is desirable to set the target rotational speed (Mset) to a rotational speed higher than the lower limit target rotational speed (MN).
According to the second embodiment, the target rotational speed can be set according to the electric load even when there is no large electric load for a long time during the warm-up in the cold time when the influence of the electric load is noticeable. Number stability can be increased.
Further, since the target rotational speed is gradually increased, the actual rotational speed does not change drastically, hunting of the rotational speed can be suppressed, and the stability of the idle rotational speed can be enhanced. Further, since the upper limit value of the target rotational speed is set, it is possible to prevent the rotational speed from rising due to the fluctuation of the electric load, and the power generation amount is not increased more than necessary.

Further, as a modification of the second embodiment, in the invention according to claim 2, the control means 20 determines that the power generation amount is equal to or greater than a predetermined value, and detects a value corresponding to the FR value of the generator. And the detection of the number of rotations of the generator 11, the detection of the voltage / current value, and the operation detection based on the operation selection of the specific electric load switch.
For this reason, as shown in FIG. 7, the control means 20 includes a generator rotation speed detection means 41 for detecting the rotation speed of the generator 11, a voltage / current detection means 42 for detecting a voltage / current value, and a specification. As an electrical load switch, the power generation amount for detecting the duty value Dfr is the FR value of the FR terminal indicating the power generation state of the generator 11 as the power generation amount (work amount) corresponding to the electric load applied to the internal combustion engine 1. The detection means 43 communicates.
Thereby, the FR value of the FR terminal indicating the rotation speed of the generator 11 and the power generation state of the generator 11 is directly input to the control means 20, and the state where the electric load is large is reliably detected, and the magnitude of the electric load is increased. The optimum target speed can be set according to the situation.

FIG. 8 shows Embodiment 3 of the present invention.
The feature of the third embodiment is the invention according to claim 3 in the following points. When the warm-up completion determination is not satisfied (when the warm-up completion determination is not satisfied), the control unit 20 determines to prohibit perturbation that periodically varies the target air-fuel ratio of the internal combustion engine 1. The target rotational speed of the internal combustion engine based on the electric load is calculated during the determination of prohibition of basation.
The perturbation mentioned above is to periodically move the target air-fuel ratio (A / F) during the operation of the internal combustion engine 1 with a certain specific width instead of being constant. As a result, deviations caused by individual differences of parts such as each detection means can be anticipated to some extent, and stable exhaust gas performance can be obtained by the detection means within the tolerance in the mass-produced product.
In the third embodiment, the intake system parts such as the intake manifold 4 are cooled at the start at a low temperature, and the fuel is injected with an increased amount than usual because of the large engine friction. Due to the fact that the load on the generator 11 is light and the intake pipe absolute pressure is low, droplets are generated at the tip of the fuel injection valve 29, and the droplets fall into the fuel chamber. Spikes occur. As described above, when a rich spike occurs, the air-fuel ratio (A / F) changes suddenly, resulting in fluctuations in the rotational speed, which gives the driver an unpleasant feeling.
For this reason, in a vehicle such as an MT vehicle, as shown in FIG. 8, for a vehicle having a lower intake pipe absolute pressure during idle operation than an AT vehicle, Until the warm-up completion is completed (warming-up completion determination is established), perturbation of the air-fuel ratio (A / F) is prohibited. By simultaneously performing the contents of prohibiting perturbation and setting the current target rotational speed high only at the time of cold start, the hunting of the rotational speed can be suppressed and the stability of the idle rotational speed can be improved.

  The idle control device according to the present invention can be applied to internal combustion engines of various vehicles.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 3 Intake passage 11 Generator 16 Idle control apparatus 17 Bypass passage 19 Idle air amount control valve 20 Control means 22 Crank angle detection means 24 Water temperature detection means 26 Electric load detection means 27 Air conditioner switch 28 Shift range switch 29 Fuel injection valve 38 Electric Load Calculation Unit 39 Speed Control Unit 40 Warm-up Completion Determination Unit

Claims (5)

  Each detection means for detecting the operation state including the water temperature, the rotation speed, and the electric load of the internal combustion engine is provided, and one or more target rotation speeds are calculated based on the operation state detected by each detection means, and finally -Idle control of an internal combustion engine provided with a control means for performing rotational speed feedback control for setting one target rotational speed and changing the intake air amount so that the rotational speed of the internal combustion engine matches the final target rotational speed In the apparatus, a power generation amount detecting means for detecting a power generation amount corresponding to an electric load applied to the internal combustion engine is provided, and the control means completes warming up of the internal combustion engine based on a water temperature at start-up or a water temperature after a predetermined operation. On the other hand, the start-up water temperature is higher than a preset value provided separately from the warm-up determination, does not satisfy the warm-up completion determination, and the rotational speed of the internal combustion engine is smaller than the initial target rotational speed by a predetermined amount The initial target rotational speed is incremented and updated in advance by a predetermined amount as the target rotational speed calculated based on the electrical load when the constant rotational speed or higher and the amount of power generation exceeds the predetermined value continues for a predetermined time. An idle control device for an internal combustion engine, characterized in that it can be increased to an upper limit target rotational speed.   The control means determines that the power generation amount is a predetermined value or more, detects a value corresponding to the FR value of the generator, detects the number of rotations of the generator, detects a voltage / current value, The idle control device for an internal combustion engine according to claim 1, wherein the idle control device is performed by any one of operation detection based on operation selection of an electrical load switch.   The control means determines to prohibit perturbation that periodically varies the target air-fuel ratio of the internal combustion engine when the warm-up completion determination is not satisfied, and based on the electric load during the perturbation prohibition determination The idle control device for an internal combustion engine according to claim 1 or 2, wherein the target rotational speed is calculated.   The control means determines completion of warming-up of the internal combustion engine based on the water temperature at start-up or the water temperature after a predetermined operation, while the water temperature at start-up is higher than a set value provided separately from the warm-up determination in advance, and The idle control device for an internal combustion engine according to any one of claims 1 to 3, wherein a minimum target rotational speed based on an electric load is set when the warm-up completion determination is not satisfied.   The control means calculates a target rotational speed based on the water temperature of the internal combustion engine, and a plurality of target rotational speeds including a target rotational speed calculated based on the water temperature and a target rotational speed calculated based on an electrical load. 5. The idle control device for an internal combustion engine according to claim 4, wherein a final target rotational speed is selected by mutual comparison.

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