JPH01177417A - Cooling controller for internal combustion engine with turbocharger - Google Patents

Abstract

PURPOSE:To precisely drive a plurality of electric fans for cooling an engine by controlling each fan according to a cooling water temperature at the down stream side of a turbocharger and a lubricating oil temperature of the engine when the stopping state of the engine is detected. CONSTITUTION:An engine 1 has a turbocharger 4 interposed on the way of an intake pipe 2 and an exhaust pipe 3. A radiator fan and a bonnet fan are respectively installed in an engine room, and each fan is respectively driven by each electric motor 29, 30 and also each electric motor is respectively controlled by ECCU 15. In this construction, when an ignition switch 25 detects the stopping state of the engine 1, the motors 29, 30 are respectively controlled by ECCU 15 according to each output of means 24 for detecting a cooling water temperature at the down stream side of the turbocharger 4 and means 16 for detecting the lubricating oil temperature of the engine 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cooling control device for an internal combustion engine with a turbocharger, and in particular to a cooling control device for an internal combustion engine with a turbocharger, and in particular, to control the temperature rise of the turbocharger and the temperature in the engine room caused by the temperature rise after the engine is stopped. The present invention relates to a control device that can appropriately suppress the rise.

(Prior Art and its Problems) Conventionally, as a cooling control device in an engine room, there is a device that operates and stops an electric fan provided in the engine room depending on the temperature of the engine room or the engine, for example. Disclosed in Japanese Utility Model Publication No. 55-34101, this type of control maintains the temperature in the engine room appropriately and prevents heat damage to the engine such as engine overheating and fuel vapor lock. I have to.

However, this conventional control device has a problem in that when the engine is equipped with a turbocharger, the temperature in the turbocharger and the engine room cannot be appropriately controlled after the engine is stopped.

In other words, since the turbocharger is placed in a narrow engine room and becomes hot during operation,
It is one of the main heat sources in the engine room. Furthermore, the temperature of the turbocharger increases because the turbocharger continues to rotate due to its inertia even after the engine is stopped.

On the other hand, the conventional control device has the above-mentioned engine control device.
Since the electric fan is configured to be controlled in accordance with the temperature of the turbocharger only when the engine is running, it is not possible to suppress the above-mentioned temperature rise in the turbocharger after the engine is stopped. Heat damage to the turbocharger, such as deterioration of lubrication performance due to carbonization of lubricating oil, cannot be prevented, and the temperature in the engine room also rises due to the rise in temperature of the turbocharger, which is the heat source, causing the above-mentioned heat damage to the engine. This also means that it cannot be prevented.

(Object of the Invention) The present invention has been made to solve the problem between the above-mentioned prior art, and it is possible to appropriately control the temperature inside the turbocharger and the engine room after the engine is stopped, thereby improving the temperature of the turbocharger and the engine. An object of the present invention is to provide a cooling control device for an internal combustion engine with a turbocharger, which can not only prevent the occurrence of heat damage but also perform efficient cooling without wastefully consuming a battery.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes a turbocharger, a water temperature detection means for detecting the temperature of cooling water for cooling the turbocharger downstream of the turbocharger;
an oil temperature detection means for detecting the lubricating oil temperature of the engine; a first electric fan for cooling the engine; a second electric fan installed in the engine room; a detection means for detecting the stopped state of the engine; In the cooling control device for a turbocharged internal combustion engine, the cooling control device includes first and second fan drive means that drive first and second electric fans, respectively, when the detection means detects that the engine is stopped; The apparatus further includes a control means for controlling the first and second fan drive means according to the outputs of the water temperature detection means and the oil temperature detection means.

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

FIG. 1 is an overall configuration diagram of a fuel supply control device for a turbocharged internal combustion engine to which the control device of the present invention is applied. The symbol l in the figure indicates, for example, a six-cylinder internal combustion engine, and an intake pipe 2 is connected to the upstream side of the engine l, an exhaust pipe 3 is connected to the downstream side, and a turbocharger is connected to the intake pipe 2 and the exhaust pipe 3. 4 is interposed.

The intake pipe 2 is provided with an air cleaner 5, an intercooler 6, and a throttle valve 7 in this order from the upstream side.

A throttle valve opening (Oro) sensor 8 is connected to the throttle valve 7 and converts the opening of the throttle valve 7 into an electrical signal and sends it to an electronic control unit (hereinafter referred to as rECUJ) 9.

On the other hand, the intake pipe absolute pressure (Pa
^) A sensor 10 is provided, and this PB^ sensor l
The absolute pressure signal converted into an electrical signal by E is
Sent to CU9. Also, downstream of that is the intake temperature (T^)
A sensor 11 is attached to detect the intake air temperature T^ and output a corresponding electric signal to be supplied to the ECU 9.

A fuel injection valve 12 is provided in the intake pipe 2 between the engine l and the throttle valve 7. This fuel injection valve 12 is provided for each cylinder slightly upstream of the intake valve 13 of the intake pipe 2 (only two are shown), and each injection valve 12 is connected to a fuel pump (not shown) and is electrically connected to the ECU 9. The opening time of the fuel injection, that is, the amount of fuel supplied is controlled by the signal from the EC:U9.

The engine cooling water temperature sensor (rT) is installed on the engine 1 body.
A TWE sensor 14 (referred to as wε sensor J) is provided, and this TWE sensor 14 is made of a thermistor, etc., and is inserted into the circumferential wall of the engine cylinder filled with cooling water, and the detected water temperature signal is sent to the EC.
It is supplied to U9 and a cooling electronic control unit (hereinafter referred to as rECCUJ) 15, which will be described later, and which constitutes first and second fan drive means and control means in this embodiment.

Further, a lubricating oil temperature sensor (oil temperature detecting means) (hereinafter referred to as rTOfL sensor) 16 is provided in the main body of the engine 1 to detect the lubricating oil temperature, and the detected oil temperature signal is sent to the E
Supplied to CCU15.

Engine speed sensor (hereinafter referred to as rNe sensor) 1
7 is attached around the camshaft or crankshaft (not shown) of the engine 1, and the TDC signal, that is, the engine 1
One pulse is output at a predetermined crank angle position every 180 rotations of the crankshaft, and this pulse is supplied to the ECU 9.

02 sensors 18, 18 are attached to the exhaust pipe 3 immediately downstream of the engine l, detect the oxygen concentration in the exhaust gas, and supply the detected value signal to the ECU 9. Also, exhaust pipe 3
A three-way catalyst 19 is disposed downstream of the turbocharger 4 to purify IC, Go, and NOx components in the exhaust gas.

The turbocharger 4 is of a variable capacity type as described later, and the turbocharger 4 includes a water pump 20.
and a conduit 22 with a subradiator 21 interposed therebetween. That is, water pump 20, subradiator 2
1 and the pipe 22 constitute a water-cooled turbocharger cooling system 23 that is separate from an engine cooling system (not shown), and the cooling water supplied by the cooling system 23 is used to cool the turbocharger 4. A water jacket 57 (Fig. 3) formed in the lubrication part casing 43, which will be described later.
The turbocharger 4 is cooled by circulating the air inside. Further, the pipe line 22 is branched and placed inside the intercooler 6, and cools the intake air passing through the intercooler 6. Immediately downstream of the turbocharger 4 in the turbocharger cooling system 23, a turbocharger cooling water temperature sensor (hereinafter referred to as rTwt sensor) 24 is provided as a water temperature detection means in this embodiment, and the detected water temperature signal is Supplied to ECCU15. Furthermore, an ignition switch (detection means) 25 is connected to the ECCU 15, and its on/off signal is supplied.

As shown in FIG. 2, inside the engine room 26, there is a radiator fan (first electric fan) 27 located at the front of the engine compartment that blows air in the front-rear force direction, and a radiator fan (first electric fan) 27 that is located at the upper part of the rear side and blows air downward. A bonnet fan (second electric fan) 28 is arranged to blow air.

The radiator fan 27 is driven by a first electric motor 29 and can be rotated forward or backward and its strength can be adjusted, and the bonnet fan 28 is driven by a second electric motor 30.

The ECU 9 operates when the engine 1 is operating, determines the operating state of the engine 1 based on input signals from the various sensors mentioned above, and adjusts the fuel consumption characteristics, acceleration characteristics, and other characteristics according to the determined operating state. The fuel injection time of the fuel injection valve 12, the ignition timing of the ignition device 31, etc. are calculated so that the fuel injection time of the fuel injection valve 12, the ignition timing of the ignition device 31, etc.
2. Supply to the ignition device 31. In addition, the ECU 9 supplies a drive signal to the solenoid valve 32 based on input signals from various sensors and other sensors, and drives an actuator (not shown) linked to the solenoid valve 32 and the turbocharger 4, thereby controlling the turbocharger 4. Optimize capacity control.

The ECCU 15 operates during the operation of the engine l and within a predetermined time after stopping, and controls the Twε sensor 14, Toot
Based on the input signals from the sensor 16 and the Twt sensor 24, the water pump 20 is operated/stopped, the radiator fan 27 is operated/stopped, the forward/reverse direction and strength of rotation, and the bonnet fan 28 is operated/stopped. The drive signal is transmitted to the water pump 20, the first and second electric motors 29.3
Supply to 0.

Further, the ECCU 15 is electrically connected to the ECU 9, and when the engine 1 is operating, the ECU 9 controls the operation and stop of the bonnet fan 28 via the ECCU 15, and performs fail-safe processing when the ECCUI 5 detects an abnormality. I do.

FIG. 3 shows an overall configuration diagram of the turbocharger 4. That is, the turbocharger 4 includes a casing consisting of a compressor casing 41 forming a scroll of the compressor portion, a back plate 42 that closes the back surface of the compressor casing 41, and a main shaft of the turbocharger 4 that pivotally supports the main shaft of the turbocharger 4.
It has a lubricating part casing 43 that lubricates the bearing and has a built-in structure in which cooling water circulates, and a turbine casing 44 that forms the scroll of the turbine part.

Inside the compressor casing l, there is a scroll passage 45 and an axial passage 4 to which the intake pipe 2 is connected.
6 are formed, the former 45 serving as an intake outlet and the latter 46 serving as an intake inlet.

Inside the turbine casing 44, a scroll passage 4 is provided.
7, an inlet opening 47a thereof opening in the tangential direction, an outlet passage 48 extending in the axial direction, and an outlet opening 47 thereof;
8a is formed, an inlet opening 47a and an outlet opening 48a
are connected to the exhaust pipe 3, respectively.

A bearing hole 49 formed inside the lubricating part casing 43.
50, the main shaft 52 is pivotally supported by the radial bearing metal 51 as described above.

Further, a thrust bearing metal 53 is sandwiched between the back plate 42 and the end surface of the lubricating part casing 43.

A lubricating oil introduction hole 54 is bored in the upper end of the lubricating part casing 43 in FIG. The lubricating oil is supplied to the radial bearing metal 51 and the thrust bearing metal 53 through a lubricating oil passage 55 bored inside the casing 43. The lubricating oil discharged from each lubricating part is discharged from a warm oil outlet 56 formed in the lubricating part casing 43 and collected in an oil sump (not shown).

A seal ring 64 is provided in the center hole of the back plate 2 to prevent the lubricating oil supplied to the thrust bearing metal 53 from flowing into the compressor side.

Also, fll'l? l? A water jacket 57 is formed within the section casing 43. The water jacket 57 has an annular cross section on the tarping casing 44 side of the lubricating part casing 43, and a U-shaped cross section at the upper end in FIG. pipe line 2
2 are connected at a connection part (not shown), so that cooling water is circulated, and thereby the turbocharger 4
is cooled.

As shown in FIG. 4, on the outer periphery of the fixed vane member 58 disposed at the center of the scroll passage 47,
Four fixed vanes 60 are formed to concentrically surround the turbine wheel 59. These fixed vanes 60 each have a partial arc shape, and are provided with the same width and at equal intervals along the circumferential direction. The gap between these fixed vanes 60 is opened and closed by a movable vane 63 fixed to the free end of a bin 62 rotatably attached to a back plate 61. These movable vanes 63 are fixed vanes 6
It has an arc shape with a curvature equal to 0, and is located approximately on the same circumference.

The bins 62 supporting these movable vanes 63 are respectively connected to the solenoid valve 32 and an actuator having an appropriate structure (not shown). The angle, ie the capacity of the turbocharger 4, is adjusted.

FIG. 5 is a wiring diagram showing in detail the external connection state of ECCUI5 mentioned above, EC:CUl, 5 is the terminal BINB.
9. It has At to A7. Terminal Bt is connected to the battery and battery voltage is applied thereto. Terminal B9 is ground (
body ground) terminal.

Terminal B2 is connected to an on/off terminal of a normal ignition switch 25. On the other hand, unlike this, terminal B3 is connected to the battery even when the ignition switch 25 is off. When the ignition switch 25 is turned off while the engine 1 is running, the engine 1 stops and the ECU 3 is also switched off and becomes inactive (excluding the memory storage function). The terminal B2 is provided to be connected to the battery regardless of whether the ignition switch 25 is turned off or not, in order to operate the engine for a predetermined time as necessary even after the engine is stopped. The operating time of the ECCU1 5 after the engine is stopped is set by a timer that is activated when the ignition switch 25 is turned off.

Regarding the setting time of the timer for ECCU15CC after the engine is stopped, the electric radiator fan 2
7. Since at least one of the bonnet fan 28 and the water pump 20 is driven, the vehicle should be designed from both of these perspectives in order to minimize battery consumption and increase the cooling effect. The size of the engine room is determined by taking into account the size of the engine room, the layout of each part, etc. - By way of example, the operational time of such ECCU15 is set to 15 minutes. .

During the predetermined time set by the timer for the ECCU15CC, the ECCU15 as an integrated cooling unit always receives voltage from the battery regardless of the state of the ignition switch, and becomes controllable.When the predetermined time elapses, the ECC: [ The predetermined cooling control operation by No. 15 is discontinued.

Terminals A1 to A3 are Twε sensor 14 and Twr sensor 24
and a detection signal input terminal of the Ton sensor 16, which is connected to each sensor. The terminal A4 is a ground terminal for the signal system of the internal circuit of the ECCU15. Further, the terminal A6 is connected to an air conditioner (A/C) unit 70, and an on/off signal for the air conditioner switch is input thereto.

Terminals 84 to B6 are terminals for controlling the radiator fan 27,
It is connected to the drive circuit 290. The drive circuit 290 includes coils 291a and 292a for switching between weak rotation and strong rotation during normal rotation, and a normal oven contact 291.
b, 292 b, first and second relay circuits 29! and 292, coils 293a and 294a for switching forward and reverse rotation, and normally closed terminal 293.
b.

294b and normally open terminal 293c, 2
04c, the third and fourth relay circuits 2E13.
294 and a resistor 295, terminal B4 for instructing low speed (LOW) rotation of the radiator fan is connected to the first relay circuit 291, and terminal B4 for instructing high speed (Ill) rotation of the radiator fan.
5 is connected to the second relay circuit 292, and the same reverse rotation (REV)
The instruction terminal B6 is connected to each of the third and fourth relay circuits 293
．． It is connected to 294.

The rotation strength and forward/reverse rotation of the radiator fan 27 is determined as follows.

In the case of weak rotation during normal rotation, a low level output is output to terminal B4. As a result, the first relay circuit 291 is activated, the drive current reduced by the resistor 295 flows through the first electric motor 29, and the radiator fan 27 rotates at a low speed.

In the case of strong rotation, a low level output is output to terminal B5, and the second relay circuit 292 is activated. In this case, a large drive current flows through the electric motor 29 and the radiator fan 27
rotates at high speed.

In the case of reverse rotation, a high level output is output to terminal B6,
The third and fourth relay circuits 293 and 294 are activated, and each relay contact is a normally open terminal 293c.

Switch to 294c side. As a result, the polarity of the voltage applied to the motor 29 is reversed, and the drive current is reduced by the resistor 295, causing the radiator fan 27 to rotate in reverse at a low speed.

The reverse rotation drive is performed continuously or intermittently within a predetermined period of time after the engine is stopped.

When the radiator fan 27 is reversely rotated, the air in the engine room 26 is discharged from the inside to the front of the vehicle, as shown by the arrow in FIG.

Terminal B7 is a terminal for controlling the bonnet fan 28, and is connected to a relay circuit 301 consisting of a coil 301a in a drive circuit 300 and a normal oven contact 301b.

Further, the drive circuit 300 is provided with a dedicated fuse 310. The bonnet fan 28 is driven, unlike the above-described one, only by being turned on and off by the second electric motor 30, and its operation and stopping are performed by outputting high-level and low-level outputs to the terminal B7.

The drive control of the bonnet fan 28 is performed continuously or intermittently during the operation of the engine 1 and within the predetermined time period after the engine is stopped.

Terminal B8 is a terminal for controlling the water pump 20, and connects the third electric motor 201 for driving the water pump 20 and the coil 20.
2a and a relay circuit 202 consisting of a normal oven contact 202b. The drive circuit 200 is also provided with a dedicated fuse 210. The water pump 20 is also driven only in an on/off manner as in the case of the bonnet fan 28 described above, and its operation and stopping are performed by outputting high level and low level outputs to the terminal B8.

The drive control of the water pump 20 is performed continuously or intermittently in place of the bonnet fan 28 during the operation of the engine 1 and within the predetermined time after the engine is stopped.

Terminals As and AT are connected to the ECU 9. The terminal A
6 is a signal input terminal for controlling the water pump 20 from the ECU 9, and when performing control based on the engine operating state according to the engine rotation speed, engine water temperature, intake air temperature, etc. when the engine I is operating, the operating state The control signal for the water pump 20 obtained based on the ECU
9 to terminal A6. The terminal A7 is a fail-safe output terminal, and when an abnormality is detected, a control signal for fail-safe instruction is sent from the terminal 7-A7 to the ECU 9.
Based on this, the ECU 9 is able to perform a predetermined fail-safe operation.

EC:CU l 5 is supplied with various input signals, shapes the input signal waveform, corrects the voltage level to a predetermined level,
Input circuit with functions such as converting analog signal values into digital signal values, central processing circuit (CPU), C:P
storage means for storing various arithmetic programs and arithmetic results executed by U, and the terminals 84 to B8. It is composed of an output circuit that sends an output to the AT, and further includes a timer and the like for intermittent control of the water pump zO and the like.

Figure 6 shows the radiator fan 27 after the engine has stopped.
and a flowchart of a subroutine for setting the operating time tpAs (hereinafter referred to as "fan operating time") of the bonnet fan 28. This program is executed only once immediately after the engine stops. In this case, the radiator fan 27 is driven in reverse, and as a result, cooling air flows into the engine room 26 from the bonnet fan 28 side through the vicinity of the engine 1st class to the radiator fan 27 side, as shown by the arrow in FIG. It is formed.

First, in step 601, the cooling water temperature TWT is read based on the input signal from the Twr sensor 24, and the lubricating oil temperature ToIL is read based on the input signal from the TotL sensor 16. Next, according to the cooling water temperature TWT and the lubricating oil temperature Ton read in step 601, the fan operating time tF is calculated based on the tFAN map stored in the ECC: U15.
Determine AN (step 602), and calculate the fan operating time F.
The radiator fan 27 and bonnet fan 28 over the AN are operated at the same time, and the tree program is ended.

FIG. 7 is a diagram showing the above-mentioned LEAN map. As shown in the figure, the tPAN map includes three reference values TWTI, TWT2, and TWTI for the cooling water temperature TW.
(e.g. 90.95 and 100°C, respectively) and the two groups 71Tl value 1”0 for the lubricating oil temperature “l”ort.
IL1 and TO[L2 (e.g. 100 and 105°C, respectively), depending on the TWT and TotL values.
The fan operation time LEAN is divided into 2 regions, and for each region, tFANI~pAs is set as the fan operating time LEAN.
e (for example, 0.3.5.6.8.9.1
0 and 12 minutes) are set.

That is, as is clear from the figure, fan operating time 1. F
The higher the cooling water temperature TW and flWI? if
f The higher the oil temperature TOIL is, the larger the value is set.

In this way, fan operation time 1:, FAN, cooling water temperature T
The cooling water temperature TWT is set according to not only wr but also the lubricating oil temperature To+L.Since the specific heat of the cooling water is small, the cooling water temperature TWT is set according to the turbocharger temperature at the time of stop, which reflects the influence of external factors such as running wind. On the other hand, since the lubricating oil has a large specific heat, the lubricating oil temperature TOIL is hardly influenced by external factors and reflects the load state of the engine before stopping. Therefore, by setting the fan operating time t and FAN as described above according to the cooling water temperature Twr and the lubricating oil temperature Torc, external factors and engine load conditions are comprehensively taken into account, and the The radiator fan 27 and the bonnet fan 28 can be operated in accordance with the temperature change of the turbocharger. As a result, the temperature inside the turbocharger and engine room can be appropriately controlled after the engine has stopped, which not only prevents heat damage to the turbocharger and engine, but also enables efficient cooling without wasting battery power. It can be carried out.

In this embodiment, the radiator fan 27 and the bonnet fan 28 are operated synchronously, but the present invention is not limited to this. Set the operating time and turn on both fans 27.
The operation of 28 may be controlled respectively.

Furthermore, in this embodiment, the lubricating oil temperature "rott" is detected near the engine 1, but as mentioned above, the lubricating oil has little temperature change due to external factors, and is shared by the engine 1 and the turbocharger 4. Therefore, even if this is detected near the turbocharger 4, the same effect as described above can be obtained.

Furthermore, in this embodiment, one of the parameters for setting the operating time LPAN of the radiator fan 27 and the bonnet fan 28 is the turbocharger cooling water temperature TWT, which is the temperature of the cooling water of the turbocharger 4. By setting the engine cooling water temperature TWE as the engine cooling water temperature TWE and appropriately setting the values tFANl to tFAN8 shown in FIG. 7, the same effect as described above can be obtained.

(Effects of the Invention) As described in detail above, the present invention provides a cooling control device for an internal combustion engine with a turbocharger. After the engine is stopped, the drive of the first electric fan that cools the engine and the second electric fan installed in the engine room is controlled, so external factors and the engine load condition before the engine is stopped are controlled. The first and second
Therefore, the temperature in the turbocharger and engine room can be appropriately controlled after the engine is stopped, which not only prevents heat damage to the turbocharger and engine but also protects the battery. Effects such as efficient cooling can be achieved without wasteful consumption.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a fuel supply control device for a turbocharged internal combustion engine to which the control device of the present invention is applied;
The figure is a schematic diagram of the inside of the engine room of the engine-equipped vehicle, FIG. 3 is a vertical cross-sectional view of the turbocharger, FIG. 4 is a view taken from the line IV-IV in FIG. Figure 5 is a wiring diagram showing the external connection status of the ECCU, Figure 6 is a flowchart of the subroutine for setting the operating time of the radiator fan and bonnet fan, and Figure 7 is for setting the operating time of the radiator fan and bonnet fan. Cooling water temperature TWT and lubricating oil temperature Tax
*It is a map according to. l...Internal combustion engine, 4...Turbocharger, 1
5...Electronic control unit (ECCU) for cooling
(first and second fan drive means, control means), 16.
... Lubricating oil temperature (ToIt) sensor (oil temperature detection means), 2
4...Turbocharger cooling water temperature (TwT) sensor (
water temperature detection means), 25... ignition switch (
Detection means), 26...engine room, 27...radiator fan (first electric fan), 28...bonnet fan (second electric fan). Applicant Honda Motor Co., Ltd.

Claims (1)

[Claims] 1. A turbocharger, a water temperature detection means for detecting the temperature of the cooling water downstream of the turbocharger, which cools the turbocharger, an oil temperature detection means for detecting the lubricating oil temperature of the engine, and a first coolant for cooling the engine. an electric fan, and a second electric fan installed in the engine room.
A cooling control device for an internal combustion engine with a turbocharger, comprising a detection means for detecting a stopped state of the engine, and first and second fan drive means for respectively driving the first and second electric fans. It is characterized by comprising a control means for controlling the first and second fan drive means according to the outputs of the water temperature detection means and the oil temperature detection means when the means detects a stopped state of the engine. Cooling control device for internal combustion engine with turbocharger.