JPS6245948A - Idling speed controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve a restarting characteristic at the time of high temperature in particular, by altering the specified engine speed on the basis of an engine temperature, in case of a controller which increases a suction air quantity at the time of engine starting and, when the engine speed goes beyond the specified one, decreases this increment portion. CONSTITUTION:In case of a controller bearing the above caption which is provided with a suction air quantity regulating device M3 constituted of installing a control valve in the bypass pipe line installed in a suction passage of an internal combustion engine 1 so as to bypass a throttle valve, it increases a suction air quantity at the time of starting and, when the engine speed detected by an engine speed detecting device M2 goes beyond the specified one, controls the suction air quantity regulating device M3 so as to decrease this increment portion. In this case, this specified engine speed is made so as to be altered by an altering device M5 according to the engine temperature detected by an engine temperature detecting device M4. That is to say, at the time of high engine temperature, the specified engine speed is made to go up with engine temperature rise, and at the low temperature, reversely the specified engine speed is made so as to go down with the engine temperature rise.

Description

[Detailed Description of the Invention] Object of the Invention [Industrial Application Field] The present invention relates to an idle rotation speed control device for an internal combustion engine,
More specifically, the present invention relates to an idle rotation speed control device for an internal combustion engine that is effective when starting the internal combustion engine when the engine is at a high temperature.

[Prior Art] In an environment where the outside temperature is high, after operating an internal combustion engine in a high load state or a rotational state suitable for high-speed driving, the operation of the core internal combustion engine is stopped, and an attempt is made to start it again. This causes the idle rotational speed of the internal combustion engine to decrease and fluctuate, and in severe cases, the baby may become unable to move. This stops the operation of the internal combustion engine in a high temperature environment, e.g.
After about 0 minutes, the fuel oil 31 vaporizes due to the temperature rise in the combustion system, and even if fuel is supplied at restart, the fuel density has decreased and the air-fuel ratio becomes lean. This is something that occurs. Conventionally, as a countermeasure for such problems, for example, when the engine temperature is higher than a predetermined temperature (high temperature start), the amount of intake air is increased to increase the i~silk of the internal combustion engine, and the idle rotation speed of the internal combustion engine is lower than the predetermined rotation speed. A device has been proposed that gradually reduces the increase in the amount of intake air when the intake air amount exceeds the amount.

[Problems to be Solved by the Invention] In 11, the idle rotation speed control device for an internal combustion engine according to the prior art has a problem in which the idle rotation speed always exceeds a certain predetermined rotation speed at the time of restarting at a high temperature. control was terminated. However, during a high-temperature restart, the actual state of the internal combustion engine, especially the fuel system, varies depending on factors such as the previous operating state of the internal combustion engine and the environmental temperature. For this reason, conventional devices are only able to perform one-way control based on a constant, predetermined rotational speed that does not necessarily correspond to the actual temperature (in particular, internal combustion), and the idle rotational state during re-movement can always be adjusted appropriately. There was a problem that it was not possible to control the situation.

The present invention aims to solve the above problems, and provides an idle rotation speed control device for an internal combustion engine that improves the restart characteristics of an internal combustion engine in a high temperature state and always controls the idle rotation speed after startup to a suitable value. The purpose is to do something.

[Means for Solving the Problems] The present invention adopts the configuration shown in Fig. 1 in order to solve the above problems. Fig. 1 shows the basic concept of the present invention. 1. As shown in FIG. 1, the present invention includes a rotational speed detection means M2 for detecting the rotational speed of the internal combustion engine M1, which increases the intake air amount of the internal combustion engine M1 at the time of starting, and increases the rotational speed of the internal combustion engine M1. An idle rotation speed control device for an internal combustion engine, comprising: an intake air amount adjusting means M3 that reduces the increase in the intake air amount when the rotation speed detected by the speed detection means M2 exceeds a predetermined rotation speed; , Further, engine temperature detection means M for detecting the temperature of the internal combustion engine M1.
4, and the intake air amount adjusting means M based on the detected temperature.
5. A rotation speed control device for an internal combustion engine, characterized in that it is equipped with: a changing means M5 for changing the predetermined rotation speed used in the engine 3;

Here, the rotational speed detection means M2 detects the rotational speed of the internal combustion engine M1. For example, internal combustion (actual M
Alternatively, it may be configured to detect the rotational speed of the camshaft V of the rib coater for the disc 1 of the internal combustion engine M1.

The intake air amount adjusting means M3 is the rotational speed detecting means M
The intake air amount of the internal combustion engine M1 is adjusted according to the rotational speed detected by the engine M1.

For example, a bypass pipe may be provided in the intake passage of the internal combustion engine M1, and the amount of intake air may be adjusted by adjusting the opening degree or controlling the opening/closing time of a valve that communicates or shuts off the bypass pipe.

The engine temperature detection means M4 detects the temperature of the internal combustion engine M1. For example, it may be configured to include a water temperature sensor that measures the humidity of the cooling water of the internal combustion engine M1 and an intake passage. Further, for example, a temperature sensor may be provided in the fuel system of the internal combustion engine M1, and the temperature of the internal combustion engine may be detected by measuring the temperature of the combustion engine M1.

The changing means M5 changes the predetermined rotational speed used by the intake air adjusting means M3 based on the temperature detected by the engine temperature detecting means M4. for example,
It can also be configured as a discrete logic circuit. In addition, for example, centering around the well-known CPU, ROM, R
When the internal combustion engine M1 is equipped with a peripheral circuit element such as an AM, and is applied to a high temperature of the internal combustion engine M1 according to a predetermined processing procedure, the predetermined rotational speed is increased in response to the detected temperature increase. , the predetermined rotational speed is lowered in response to the decrease in temperature, while the internal combustion engine M is configured as follows.
When applied at a low temperature in No. 1, the relationship between the temperature change and the predetermined rotation speed is set to be reversed.

[Function] In the idle rotation speed control device for an internal combustion engine of the present invention, the intake air amount adjusting means M3 increases the intake air amount when starting the internal combustion engine M1, and the rotation speed of the internal combustion engine M1 exceeds a predetermined rotation speed. When the intake air amount increase is controlled to be reduced, the changing means M5 operates to change the predetermined rotational speed in response to the temperature detected by the engine temperature detecting means M4.

Therefore, when the internal combustion engine M1 is at a high temperature, the vaporized fuel vapor is quickly discharged, while when the internal combustion engine M1 is at a low temperature, there is a rapid warming transition to the state J.

[Example] Next, a preferred example of the present invention will be described in detail based on the drawings.

FIG. 2 is a schematic diagram of a 4-cycle 4-cylinder engine and its idle rotation speed control device, which is an embodiment of the present invention. As shown in the figure, an engine 1 has a combustion chamber 4 made up of a cylinder 2 and screws 1 to 3, and a spark plug 5 is disposed in the combustion chamber 4. The intake system of the engine 1 includes an intake valve 6, a fuel injection valve 7 provided for each cylinder and injecting fuel oil I, an intake manifold 8 where intake pipes to each cylinder gather, and an intake passage. A surge tank 9 that prevents pulsation of the intake air inside the tank, and a thrower 1 to a valve 10 that adjusts the intake flow rate. A bypass passage 11 is an air passage that bypasses the throttle valve 10, and an idle speed control valve that adjusts the intake flow rate during re-idling by varying the opening area of the bypass passage 11.
The following is simply ISCV,! m, J:, S',. )
12. l5cV pulse motor 13 that drives the l5CV
, an air flow meter 14 that measures the amount of intake air, and an air cleaner 15 that purifies the intake air. The exhaust system of the engine 1 includes an exhaust valve 16, an exhaust manifold 17 in which exhaust pipes from each cylinder are collected, and a three-way catalyst 18 for purifying exhaust gas. Furthermore, the engine 1 includes an igniter 19 that includes an ignition coil and generates the high voltage necessary for ignition.
, linked to a crankshaft (not shown), the igniter 19
The engine has a distributor 20 that distributes and supplies the high voltage generated in the engine to the spark plugs 5 of each cylinder.

Detectors for detecting each state of the engine 1 include a cooling sensor 21 installed in the cylinder block of the engine 1 to detect the temperature of the cooling water, and a sensor 21 installed in the aphrometer 14 described above. an intake air temperature sensor 22 that detects the intake air temperature; No 2
3. Oxygen concentration sensor 2 installed in the exhaust manifold 17 described above to detect the residual oxygen concentration in the exhaust gas.
1. It is installed in the disc 1-reviewer 20 described above (it also serves as a rotational speed sensor that outputs 24 timing signals during one revolution of the shaft of the disc 1-reviewer 20, that is, two revolutions of the crankshaft). rotation angle sensor 25,
Similarly, a cylinder discrimination sensor 2 outputs one timing signal for each revolution of the shaft of the distributor 20.
6 are arranged respectively. The detection signals of each of the above-mentioned sensors and the signal from the starter 27 that starts the engine 1 are input to an electronic control unit (hereinafter simply referred to as ECU).
The pulse motor 13 and the igniter 19 are driven and controlled.

Next, the configuration of the FCU 30 will be explained based on FIG. 3. The ECU 3O is a CPU that inputs and calculates data detected by the sensors described above according to a control program, and performs processing to drive and control the fuel injection valve 7, the 15CV pulse motor 13, and the igniter 19.
30a, a ROM 30b in which initial data such as the control program and maps are stored in advance; a RAM 30G from which data input to the ECU 3O and data necessary for arithmetic control are temporarily read; It is configured as a logic operation circuit centered around a backup RAM 30d backed up by a battery to hold data etc. necessary for subsequent control of the engine 1, and input/output circuits interconnected via a common bus 30e. Capo-1-30 f.

The input boat 30CI and the output port 30h perform input/output with external sensors and devices.

ECU3O has an air flow meter 14. Water temperature sensor 21.
Buffers 30i and 30j for the output signal of the intake air temperature sensor 22
, 30, the signals from each buffer are selectively sent to the CPU 30.
It has a multiplexer 30m that outputs to
These signals are sent to the CPU 30 via the input/output port 30f.
input to a. Further, the FCU 30 includes a buffer 30r) for the output signal of the oxygen concentration sensor 24, and a buffer 30r) for the output signal of the oxygen concentration sensor 24.
Based on the output voltage of 0p? ((outputs a signal when the voltage exceeds the voltage)) It has a waveform shaping circuit 30r that shapes the waveforms of the output signals of the comparator 30q, the cylinder discrimination sensor 26, and the rotation angle sensor 1J25. Position sensor 23. Signal tel of starter 27: Input to CPU 30a via input capo 1 300. Furthermore, ECU 3O controls TSCV pulse motor 13.
Fuel oil 91 injection valve 7. It has drive circuits 308, 30t and 30L+ for supplying drive current to the igniter 19, respectively, and these are controlled by the CPU 30a via 30h to the output capo-1.

The 11 idle rotational speed control processes executed by the FCU 30 will be described below based on the Fn-delays 1 to 1 shown in FIG. 4, which are executed upon startup of the engine 12. First, the basics of this process will be explained.

(1) When the engine 1 must be in a high temperature state, set the rotational speed setting value at idle to the highest value, and increase the intake air amount while listening to l5CV12 until the rotational speed setting value is met. 1 injection time τ is lengthened to increase the amount of fuel supplied (steps 110, 120, 130, 14
0,150,160.170>.

(2) When the engine 1 is at room temperature, set the rotational speed setting value at idle to the normal value, turn on TSCV12 until the rotational speed setting value is met, and turn 15CV12 on when the rotational speed setting value is met. Close to the specified opening degree (steps 110, 120° 130, 180, 200, 170
>.

(3) When the engine 1 is at a low temperature, the vapor pressure of the fuel is low and the friction of the drive mechanism is high, so the rotation speed setting value at idle should be set to a value higher than the normal value in (2) above. 15C until the rotation speed setting value is met.
V12 is fully opened and -13-.

When the rotation speed setting value is met, 15CV12 is closed to a predetermined opening degree (steps 110, 190, 200°170).

Next, details of this process will be explained. First, in step 100, the coolant temperature T of the engine 1 is determined by the coolant temperature sensor 9-21.
The intake air temperature THA is detected by the intake air temperature sensor 22, and the rotational speed Ne is detected by the rotation angle sensor 25.

Next, the process proceeds to step 110, where the cooling water temperature T I-I W detected in step 100 is determined as the water temperature first reference value TW1.
It is determined whether or not the value is greater than or equal to the value. In addition, in the case of this example,
The water temperature first reference value TWI is 30' IC]. If the cooling water temperature T I-I W is equal to or higher than the water temperature first reference value TW1, the process proceeds to step 120. Here, it is similarly determined whether the cooling water temperature THW is greater than or equal to the water temperature second reference value TW2. In the case of this embodiment, the water temperature second reference value TW2 is 1100 [C]. Cooling water temperature T I-I
If W is equal to or higher than the water temperature second reference value W2, the process proceeds to step 130. Here, we will explain step 10, which we have already skipped.
The intake air temperature H△ detected at 0 is the air temperature base A1 (
It is determined whether the value is equal to or greater than the value TAI. d3, in the case of this example, the air temperature reference value TA1 is 70' IC]
It is. Is the intake air temperature Tl-1Δ the air temperature base? (If the value is greater than or equal to 1 value TΔ1, proceed to step 14.0.

As shown in ``2'' (if all the determinations in steps 110, 120, and 130 result in YFS, the cooling water temperature TI-IW
This is a case where the engine 1 is in a high temperature state because both the intake air temperature T I-I A and the intake air temperature T I-I A are high. Therefore, in step 140, the rotation speed Ne of the engine 1 detected in step 100 is set to a first rotation speed, which is the highest setting value.
It is determined whether or not it is equal to or greater than a set value N1. In this embodiment, the rotational speed first set value N1 is 1000 [r,
p, m'l.

If the rotational speed Ne is the first rotational speed setting value N1)11t, it is determined that the idle state at the time of startup is still unstable, and the process proceeds to step 150. Here, l5C
The V-pulse motor 13 is rotationally driven to fully open the TSCV 12. As a result, the intake air amount of the engine 1 cannot be increased. In the subsequent step 160, a process is performed to extend the fuel injection time τ by 20%. As a result, the fuel IG+supply m to the engine 1 is increased m.

In this way, when the engine 1 is started, which is in a high temperature state and the fuel density has decreased due to fuel vaporization, etc., the air-fuel ratio is controlled to the 113 rich side, and the NE
To XT] This process ends with warping. On the other hand, if the control shown in above) is performed and the rotational speed NC in the idle state becomes equal to or higher than the first rotational speed setting value N1, the determination in step 1=10 becomes YIES and the process proceeds to step 170. . Here, assuming that the idle state of the engine 1 is stable, the JSCV pulse motor 13 is rotationally driven,
After the process of closing the TSCV 12 to a predetermined opening degree is performed, the process is pulled out to NEXT to end this process.

If it is determined in step 120 that the cooling water temperature T I-I W is less than the second water temperature reference value TW2, or if the cooling water temperature T I-I W is determined to be less than the second water temperature reference value TW2 (even if the cooling water temperature T I-I W is equal to or higher than the second water temperature reference value TW2), In step 130, the intake air temperature T
If it is determined that HA is constant at the air temperature reference value TAI end vortex, the process proceeds to step 180. In this way, if the determination in either step 120 or 130 is No, this means that the engine 1 is at normal temperature. Therefore, in step 180, it is determined whether the rotational speed Ne detected in step 100 is equal to or higher than the second rotational speed setting value N2. In this embodiment, the second rotation speed setting value N2 is 500 [r, p, m]. If the rotation speed aNe is less than the second rotation speed setting value N2, it is determined that the idle state at the time of startup is still unstable, and the process proceeds to step 200. Here, as in step 150 described above, the process of fully opening the l5CV12 is carried out, and after the intake air amount is increased, the process exits to NEXT and the present process ends.

On the other hand, due to the increase in the amount of intake air mentioned above, the rotational speed Ne
is equal to or higher than the second rotational speed setting value N2, the determination in step 180 becomes YES, and the process proceeds to step 170, in which the rscv 12 is closed to a predetermined opening degree as described above, and then handled in the NFXT ( Press to end this process.

If it is determined in step 110 that the cooling water temperature T I-I W is equal to the water temperature first reference value TW1, the process proceeds to step 190 . In this way, if the determination in step 110 is No, this means that the engine 1 is in a low temperature state. Therefore, in step 190, the above step 1
The rotational speed Ne detected at 00 is the third rotational speed setting value N
It is determined whether the number is 3 or more. In addition, in this embodiment, the rotational speed third set value N3 is 800 [r, I), m]
It is.

If the rotational speed Ne is less than the third rotational speed setting value N3, it is determined that the idle state at the time of startup is still unstable, and the process proceeds to step 200. Here, the previously mentioned J
: After the sea urchin intake air amount is increased, the process is terminated by exiting to NFXT.

On the other hand, due to the increase in the amount of intake air mentioned above, the rotational speed Ne
If the rotational speed is equal to or higher than the third set value N3, the determination in step 190 is YFS, and the process proceeds to step 170, where the intake air amount increase is reduced as described above. , it can be handled as NFXT and this process ends.

Thereafter, this process is repeatedly executed as the engine 1 is started.

In this embodiment, the engine 1 is an internal combustion engine (actual M1
As a result, the processing (step 100) executed by the rotation angle sensor 25, E CIJ 30, and the FCU 30 is performed as the rotation speed detection means M2, and further, the process (step 100) executed by the rotation angle sensor 25, the E CIJ 30, and the FCU 30 is performed by the l5CV12, the l5CV pulse motor 13, the ECU3O, and the FCU.
30 (steps 150, 170,
200> and each function as an intake air amount adjusting means M3. In addition, the water temperature sensor 21, the intake temperature sensor 22, and the ECU 3
The process executed by the ECU 3O and the FCU 30 (step 100) is performed as the engine temperature detection means M4, and the process executed by the ECU 3O and the FCU 30 (step 110,
120. '130, 140, 180, 190) respectively function as the changing means M5.

As explained above, in this embodiment, when the engine 1 is started, the cooling water temperature T I - I W and the intake air temperature THA are measured, and the rotation speed is adjusted depending on the degree of each temperature in the case of a high temperature start. First set value N1. When starting at normal temperature, the second rotation speed setting value N2. Furthermore, in the case of a low-temperature start, the rotation speed third set value N3 is set respectively, and the stability of the idle state is determined based on each set value. If the idle state is unstable, listen to l5CV12 and start the engine. In addition to increasing the amount of air, control is also performed to avoid increasing the fuel injection 6J, especially during high-temperature fetal movements. Therefore, when starting the engine 1, after measuring the cooling water temperature T1-IW and the intake air temperature T1-18 to understand the state of the engine 1, the set value of the idle rotation speed is adjusted to the above temperature conditions. Since the opening/closing control of JSCVl 2 is performed according to the specified timing, it is possible to control the idle rotation speed appropriately corresponding to the state at the time of starting the engine 1.As a result, when the engine 1 is in a high temperature state, By increasing the idle rotational speed of the engine 1, the exhaust of fuel vapor vaporized due to the high temperature is accelerated and the cooling of the engine 1 is accelerated. On the other hand, when the engine 1 is in a low temperature state, the engine 1 is By increasing the idle rotation speed, the engine 1 can be quickly brought to a warm-up state.

In particular, when the engine 1 is started at a high temperature, the fuel 1 supplied to the fuel system is vaporized due to the temperature rise in the fuel system, and the air-fuel ratio becomes lean by increasing the amount of intake air. Since the speed is increased and the vaporized fuel vapor is quickly discharged, and the amount of fuel supplied is increased to correct the air-fuel ratio, it is possible to improve the starting characteristics and to stabilize the idle rotation state.

Roughly speaking, if each setting value of the rotational speed is stored as a map corresponding to the temperature, more suitable control becomes possible.

In this embodiment, the intake air temperature sensor 22 installed in the air flow meter 14 is used to measure the intake air temperature T]-1△, but the intake air temperature sensor 22 installed in the surge tank 9 of the intake system may It has a similar effect on Qin.

Furthermore, in this embodiment, the opening degree adjustment of l5CV12 is
Although the configuration is such that the CV pulse motor 13 is used, it is also possible to use an electromagnetic solenoid to adjust the opening of the CV'12 by the pulse duty ratio of the control signal, for example. This configuration has the advantage that the opening degree of l5CV12 can be adjusted with good responsiveness.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments in any way, and it goes without saying that the present invention can be implemented in various forms without departing from the gist of the present invention. be.

Effects of the Invention As detailed above, the present invention provides that the intake air amount adjusting means:
When the internal combustion engine is started, the intake air is increased, and when the rotational speed of the internal combustion engine exceeds a predetermined rotational speed, the intake air amount is reduced by the increased amount. A changing means performs control to change the predetermined rotational speed based on the temperature of the rotational speed. Therefore, an excellent effect is achieved in that the idle rotational speed of the internal combustion engine can be controlled to the optimum rotational speed according to the temperature conditions of the internal combustion engine during fetal movement. As a result, when the internal combustion engine is in a high temperature state, vaporized fuel vapor can be quickly discharged and the internal combustion engine can be cooled quickly.On the other hand, when the internal combustion engine is in a low temperature state In some cases, the operating state of the internal combustion engine can be quickly shifted to a warm state.

Furthermore, there is also the advantage that the restart performance is improved, especially when the internal combustion engine is in a high temperature state.

[Brief explanation of the drawing]

Fig. 1 is a basic configuration diagram showing the contents of the present invention in WX concept, Fig. 2 is a WX approximate nr15 diagram of an engine and idle speed control device which is an embodiment of the present invention, and Fig. 3 is the same. FIG. 4 is a block diagram for explaining the IM configuration of the electronic control device, and is a flowchart 1 showing idle rotation speed control processing executed by the electronic control device in an embodiment of the present invention. Ml...Internal combustion (actual M2...Rotational speed detection means M3...Intake air amount adjustment means M4...Engine temperature detection means M5...Change means 1...Engine 12...Idle speed Con I ~ Roll valve (I
IscV) 13...TSCV pulse motor 21...Water/hot water sensor 22...Intake temperature sensor 25...Rotation angle sensor 1/30...Electronic control unit (ECU) 30 a ・CPU

Claims (1)

[Scope of Claims] 1. A rotational speed detection means for detecting the rotational speed of an internal combustion engine; and a system for increasing the intake air amount of the internal combustion engine at the time of starting, so that the rotational speed detected by the rotational speed detection means or a predetermined rotational speed is increased. An idle rotation speed control device for an internal combustion engine, further comprising: an intake air amount adjusting means for reducing the increase in the intake air amount when the amount exceeds the intake air amount; An idle rotation speed control device for an internal combustion engine, comprising: changing means for changing a predetermined rotation speed used in the intake air amount adjusting means based on the detected temperature. 2. According to claim 1, wherein the changing means increases the predetermined rotational speed in response to an increase in the temperature when the internal combustion engine is at a high temperature, and decreases the predetermined rotational speed in response to a decrease in the temperature. The idle rotation speed control device for the internal combustion engine as described. 3. Idle rotation of an internal combustion engine according to claim 1 or 2, wherein the engine temperature detection means detects at least one of a cooling water temperature, an intake air temperature, and a fuel temperature of the internal combustion engine. Speed control device. 4. According to any one of claims 1 to 3, wherein the internal combustion engine is configured to increase the amount of fuel while the engine temperature is high and the amount of intake air is being increased. The idle rotation speed control device for the internal combustion engine as described.