JP5293235B2 - Engine intake control method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy at a high degree both the enhancements of ignitability and combustibility of an engine and the improvement of filling quantity. <P>SOLUTION: A motor-driven supercharger 18 and an intercooler 57 taken as a heat exchanger on a downstream side of the motor-driven supercharger 18 are arranged in an intake passage 50. When intake temperature is low, supercharging pressure and cooling degree of the intercooler 57 are relatively made higher and lower respectively as compared with when the intake temperature is high under the same operating state of an engine. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to an engine intake control method and an apparatus therefor.

In an engine that performs supercharging of intake air, a turbocharger that is driven by using exhaust energy or a supercharger that is mechanically driven by the engine is generally used as a supercharger. However, it has also been proposed to use an electric supercharger. In Patent Document 1, particularly during the cold start of a diesel engine, by operating the electric supercharger provided in the intake passage to perform supercharging, the engine friction is increased and the in-cylinder temperature is increased. It is disclosed to improve ignitability.

JP 2005-188484 A

Incidentally, in an engine, it is important to ensure the ignitability and combustibility of the fuel injected into the cylinder, and it is also important to improve the filling amount. Increasing the supercharging pressure increases the intake air temperature, which is preferable in increasing the in-cylinder temperature and improving the ignitability and combustibility. On the other hand, when the intake air temperature is increased by supercharging, the intake air density is decreased and the filling amount is decreased, which is not preferable. In particular, in the case of a diesel engine, self-ignition is caused by compression heat, so that the ignitability at the time of starting and the subsequent combustibility are likely to be a problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an engine intake control method capable of satisfying both of ensuring ignitability and combustibility and securing a filling amount at a high level. It is to provide.

In order to achieve the above object, the following first solution is adopted in the intake control method for an engine in the present invention. That is, as described in claim 1 in the claims,
An engine in which a supercharger is disposed in an intake passage, a heat exchanger for intake air cooling is provided downstream of the supercharger , and a bypass passage that bypasses the heat exchanger is provided in the intake passage . An intake control method,
A first step of detecting intake air temperature;
A second step of determining the magnitude of the supercharging pressure of the intake air supercharged by the supercharger and the degree of cooling in the heat exchanger according to the intake air temperature detected in the first step;
A third step of controlling the supercharger to be the supercharging pressure determined in the second step and controlling the heat exchanger to be the cooling degree determined in the second step;
With
In the second step, when the intake air temperature is lower than a predetermined temperature, the supercharging pressure is determined as the maximum supercharging pressure, and the intake air supercharged by the supercharger is supplied into the cylinder through the bypass passage. To determine that the degree of cooling by the heat exchanger is minimized,
In the second step, further, at the time of warming up when the intake air temperature is equal to or higher than the predetermined temperature , the boost pressure is maximized as the intake air temperature rises from the predetermined temperature corresponding to the intake air temperature in the same operating state of the engine. Determining to gradually decrease from the supercharging pressure and to gradually increase the cooling degree of the heat exchanger,
It is like that.

According to the above solution, when the intake air temperature is high, the ignitability and the combustibility are good, while the intake density becomes small and the filling amount becomes small. Therefore, in this case, the charging amount can be improved by increasing the degree of cooling by the heat exchanger while suppressing the increase in the intake air temperature accompanying the supercharging by reducing the supercharging pressure. Conversely, when the intake air temperature is low, the filling amount is ensured, but the ignitability and combustibility tend to deteriorate. In this case, the boost pressure is increased to increase the intake air temperature and heat By reducing the degree of cooling of the exchanger, the temperature of the intake air supplied into the cylinder is increased, and the ignitability and combustibility are improved. Thus, in accordance with the difference in intake air temperature, both improvement in ignitability and combustibility and securing of the filling amount are satisfied at a high level.

In particular, when ignitability and combustibility deteriorate when the engine is cold when the intake air temperature is lower than the predetermined temperature , the intake air is cooled by supplying it into the cylinder by bypassing the heat exchanger. It can be completely prevented and ignitability and flammability can be satisfied. In addition , when the engine is warming up when the intake air temperature is equal to or higher than the predetermined temperature, the supercharging pressure is gradually decreased from the maximum supercharging pressure as the intake air temperature rises from the predetermined temperature, while the cooling degree of the heat exchanger is gradually decreased. Since the temperature is raised, it is possible to satisfy the ensuring of the ignitability and the combustibility and the securing of the filling amount at an extremely high level according to the intake air temperature.

The supercharger is an electric supercharger including a compressor wheel disposed in the intake passage and an electric motor that drives the compressor wheel (corresponding to claim 2 ). . In this case, the supercharging pressure can be changed with good response in accordance with the intake air temperature, which is preferable for sufficiently exhibiting the effect corresponding to the first aspect.

The heat exchanger is set so that refrigerant is circulated and heat is exchanged between the refrigerant and the intake air;
The degree of cooling of the heat exchanger is changed by changing the circulation speed of the refrigerant to the heat exchanger.
(Corresponding to claim 3 ). In this case, the cooling degree of the heat exchanger can be changed by a simple and general method of changing the refrigerant circulation speed.

It is the intake control method for an engine in a hybrid vehicle in which example Bei the engine to perform at least the generator and the electric motor for traveling which drives the vehicle wheels,
The supercharge is an electric supercharger;
In the second step, when the engine is started from the engine stop state, the supercharging pressure is determined as the maximum supercharging pressure, and the intake air supercharged by the supercharger is supplied into the cylinder through the bypass passage. By determining so that the degree of cooling by the heat exchanger is minimized,
(Corresponding to claim 4 ). In this case, since the engine is a hybrid vehicle, the engine is frequently repeatedly stopped and started. However, in such a hybrid vehicle, both of ensuring ignitability and combustibility and securing the filling amount are both high-level. Can be satisfied. Of course, since the supercharging is performed by the electric supercharger, the supercharging pressure can be changed with good response according to the intake air temperature.

In order to achieve the above object, the following first solution is adopted in the intake control apparatus for an engine in the present invention. That is, as described in claim 5 in the claims,
An engine in which an electric supercharger is disposed in the intake passage, a heat exchanger for cooling the intake air is provided downstream of the supercharger , and a bypass passage that bypasses the heat exchanger is provided in the intake passage Intake control device of
An intake air temperature detecting means for detecting the intake air temperature;
A controller that receives the output from the intake air temperature detection means and controls the supercharger and the heat exchanger;
With
The controller determines the magnitude of the supercharging pressure of the intake air supercharged by the supercharger and the degree of cooling in the heat exchanger according to the intake air temperature detected by the intake air temperature detecting means, The supercharger is controlled to achieve the determined supercharging pressure, and the heat exchanger is controlled to control the determined cooling degree .
The controller controls so that the supercharging pressure becomes a maximum supercharging pressure when the intake air temperature is lower than a predetermined temperature , and the intake air supercharged by the supercharger enters the cylinder through the bypass passage. By controlling so that the degree of cooling by the heat exchanger is minimized,
The controller further increases the supercharging pressure as the intake air temperature rises from the predetermined temperature corresponding to the intake air temperature in the same operating state of the engine when the intake air temperature is equal to or higher than the predetermined temperature. Control to gradually decrease from the pressure and gradually increase the degree of cooling of the heat exchanger,
It is like that. According to the above solution, an engine intake control apparatus for executing the engine intake control method according to claim 1 is provided. Moreover, since supercharging is performed by the electric supercharger, the supercharging pressure can be changed with good response according to the intake air temperature.

A preferred mode based on the above solution is as described in claim 6. That is,
The controller controls the supercharging pressure to the maximum supercharging pressure when starting the engine from an engine stop state , and supplies the intake air supercharged by the supercharger into the cylinder through the bypass passage. To control the degree of cooling by the heat exchanger to a minimum,
(Corresponding to claim 6). In this case, an engine intake control device for executing the engine intake control method according to claim 4 is provided.

According to the present invention, both ensuring ignitability and flammability and securing the filling amount can be satisfied at a high level.

The simplified top view which shows one Embodiment of this invention and shows a drive system. FIG. 2 is a system diagram showing the engine shown in FIG. 1 together with its intake / exhaust system. The principal part expanded sectional view of the engine shown in FIG. The figure which shows the example of a setting of the driving | operation area | region with an electric motor and an engine. The figure which shows the control system of this invention in a block diagram. The figure which shows the example of a setting of the supercharging pressure according to intake air temperature, and the circulating speed of cooling water. The flowchart which shows the example of control of this invention.

FIG. 1 shows a drive system of a hybrid vehicle provided with an engine 1 and an electric motor 2. The engine 1 is a multi-cylinder (in-line four-cylinder in the embodiment) diesel engine, and is used for both power generation and driving. The electric motor 2 is used for running and for regeneration.

The engine 1 (the crankshaft thereof) and the electric motor (the output shaft thereof) are positioned on the same axis, and a power transmission mechanism 3 is interposed between the engine 1 and the electric motor 2. The power transmission mechanism 3 includes a shaft member 5 in which a drive gear 4 is integrated. The shaft member 5 is positioned on the same axis line as the engine 1 and the electric motor 2, is connected to the engine 1 via the first clutch 6, and is connected to the electric motor 2 via the second clutch 7. ing.

The power transmission mechanism 3 includes a shaft member 8 in parallel with the shaft member 5. A driven gear 9 integrated with the shaft member 8 is always meshed with the drive gear 4 (configures a speed reduction mechanism). A shaft member 12 in which a drive gear 11 is integrated is connected to the shaft member 8 via a third clutch 10.

A driven gear 14 in a differential gear 13 is meshed with the drive gear 11 (configures a speed reduction mechanism). The differential gear 13 is connected to left and right drive wheels (front wheels in the embodiment) 16K and 16R via left and right drive shafts 15L and 15R.

Driving force transmission from the engine 1 to the driving wheels 16L, 16 is performed via the first clutch 6, gears 4, 9, third clutch 10, gears 11, 14, differential gear 13, and drive shafts 15L, 15R. The driving force transmitted from the electric motor 2 to the driving wheels 16L, 16 is transmitted via the second clutch 7, the gears 4, 9, the third clutch 10, the gears 11, 14, the differential gear 13, and the drive shafts 15L, 15R. Done.

FIG. 4 shows an example of setting the operation region according to the running state of the engine 1 and the electric motor 2. In FIG. 4, in the region A where the rotation speed is low and the vehicle speed is equal to or less than the middle vehicle speed, traveling is performed only by the electric motor 2. In the high vehicle speed region B, the vehicle is driven only by the engine 1. The other operation region C is an operation region using the driving forces of both the engine 1 and the electric motor 2. In the driving region C, the drive ratio between the engine 1 and the electric motor 2 is set such that the drive ratio of the engine 1 increases as the load increases or the vehicle speed increases (in the embodiment, the engine 1 and the electric motor 2). The drive ratio with the electric motor 2 is continuously variable in the range of “1:10” to “10: 1”).

When traveling only with the engine 1, the first clutch 6 and the third clutch 10 are connected, and the second clutch 7 is disconnected. Further, when traveling only by the electric motor 2, the second clutch 7 and the third clutch 10 are connected and the first clutch 6 is disconnected. When traveling with the driving force of both the engine 1 and the electric motor 2, all of the first to third clutches 6, 7, and 10 are connected.

During regeneration, the second clutch 6 and the third clutch 10 are connected and the first clutch 6 is disconnected. The engine 1 is started while the first clutch 6 and the second clutch 7 are connected and the third clutch 10 is disconnected while the engine 1 is rotationally driven by the electric motor 2. Details will be described later. In FIG. 1, 17 is a capacitor having a large capacity and high efficiency, and 18 is an electric supercharger described later. The electric motor 2 and the electric supercharger 18 are driven by receiving electric power from the capacitor 17. In FIG. 1, reference numeral 19 denotes an air conditioner (compressor), which is connected to the shaft member 8 and driven by the rotation of the shaft member 8.

2 shows an intake / exhaust system of the engine 1 shown in FIG. 1, and details of the vicinity of the cylinder head of the engine 1 are shown in FIG. In the engine 1, as shown in FIG. 3, a combustion chamber 33 is defined by a cylinder block 30, a cylinder head 31, and a piston 32. An intake port 34 and an exhaust port 35 are opened in the combustion chamber 33. The intake port 34 is opened and closed by an intake valve 36, and the exhaust port 35 is opened and closed by an exhaust valve 37. In addition, a fuel injection valve 38 is exposed to the combustion chamber 33, and a sensor S1 that is used for both temperature detection and pressure detection is also exposed.

An opening / closing cam (cam shaft) of the intake valve 36 is indicated by reference numeral 40, and an opening / closing cam (cam shaft) of the exhaust valve 37 is indicated by reference numeral 41. Each of the cams 40 and 41 is rotationally driven by a crankshaft interlocked with the piston 32, and variable valve mechanisms 42 and 43 for phase change are incorporated in the middle of the rotational drive path. Such an engine 1 is a multi-cylinder diesel engine having a plurality of cylinders spaced in a direction perpendicular to the plane of FIG. 3 (in the embodiment, an in-line four cylinder).

As shown in FIG. 2, the intake passage 50 of the engine 1 has a surge tank 51. An intake port 34 of each cylinder is independently connected to the surge tank 51 through an independent intake passage 52. In the common intake passageway 53 for supplying intake air to the surge tank 51, the air cleaner 54, the throttle valve 55 (for changing the EGR rate), the compressor wheel 56a of the exhaust turbocharger 56, in order from the upstream side to the downstream side thereof, The electric supercharger 18 and the water-cooled intercooler 57 as a heat exchanger are connected.

The common intake passage 53 has a bypass passage 53 </ b> A that bypasses the intercooler 57. That is, the bypass passage 53A has an upstream end opened to the common intake passage 53 between the compressor wheel 18a and the intercooler 57, and a downstream end connected to the common intake passage between the intercooler 57 and the surge tank 51. An opening is formed in the passage 53. A switching valve 58 is disposed in the bypass passage 53A. When the switching valve 58 is closed, the entire amount of intake air is supplied to the engine 1 through the intercooler 57. When the switching valve 58 is opened, the entire amount of intake air is supplied to the engine 1 through the bypass passage 53A (bypassing the intercooler 57). It should be noted that by adjusting the opening degree of the switching valve 58, it is possible to change the ratio of the intake air amount of the intercooler 57 and the intake air amount passing through the bypass passage 53A to a stepped type or a continuously variable type. The switching valve 58 may be disposed at the upstream end of the bypass passage 53A so that when the bypass passage 53A is fully opened, the switching valve 58 completely blocks the flow toward the intercooler 57. .

The electric supercharger 18 includes a compressor wheel 18a disposed in the common intake passage 50 and an electric motor 58b that drives the compressor wheel 58a. By driving the electric motor 18b, the compressor wheel 18a is driven and the intake air is supercharged. By changing the driving force of the electric motor 18b, the supercharging pressure capability of the electric supercharger 18 (that is, the supercharging pressure obtained by the electric supercharger 18) is changed.

The intercooler 57 is water-cooled and is connected to the radiator 80 via a supply path 81 and a return path 82. A water pump 83 is connected to the supply path 81. By driving the water pump 83, the cooling water as the refrigerant is supplied from the supply path 81 to the intercooler 57 through the intercooler 57, the return path 82, and the radiator 80 again. Become. Then, when the cooling water passes through the intercooler 57, heat is exchanged with the intake air to cool the intake air. The cooling water heated to high temperature by the intercooler 57 is, for example, between the air and the atmosphere. In this case, the heat is exchanged and cooled (the radiator fan is not shown).

The exhaust passage 60 of the engine 1 includes a turbine wheel 56b of the exhaust turbocharger 56, an oxidation catalyst 61, and a CDPF (particulate supplement filter) 62 on the downstream side of the portion where the exhaust ports 37 of the cylinders are gathered. It is connected. When the turbine wheel 56b is rotationally driven in response to the energy of the exhaust gas, the compressor wheel 56a is driven through the connecting shaft 56c, and the intake air is supercharged. The exhaust turbocharger 56 has a bypass passage 56d that bypasses the turbine wheel 56b, and a wastegate valve 56e is disposed in the bypass passage 56d. By changing the opening degree of the wastegate valve 56e, the supercharging capability (that is, the supercharging pressure obtained by the exhaust turbocharger 56) by the exhaust turbocharger 56 is changed.

The intake passage 50 and the exhaust passage 60 are connected via a first EGR passage 70 and a second EGR passage 80. One end of the first EGR passage 70 is opened to the exhaust passage 60 on the downstream side of the CDPF 63, and the other end is opened to the common intake passage 53 between the throttle valve 55 and the compressor wheel 56a. An intercooler 71 and an electromagnetic EGR valve 72 are connected to the first EGR passage 70.

One end of the second EGR passage 80 is opened to the exhaust passage 60 on the upstream side of the turbine wheel 56b, and the other end is common between the surge tank 51 and the electric supercharger 18 (the compressor wheel 18a). An intake passage 53 is opened. An intercooler 81 and an electromagnetic EGR valve 82 are connected to the second EGR passage 80. The second EGR passage 80 is provided with a bypass passage 83 that bypasses the intercooler 81. An electromagnetic switching valve 84 is connected to the upstream branch portion between the second EGR 80 and the bypass passage 83. The switching valve 84 switches between a state in which the exhaust gas from the passage exhaust passage 60 flows toward the intercooler 81 and a state in which the exhaust gas flows toward the bypass passage 83. That is, the switching valve 84 is switched so that exhaust gas (EGR gas) flows through the bypass passage 83 when the engine 1 is cold (for example, when the engine coolant temperature is less than 60 degrees C). When the engine is warm, the exhaust gas (EGR gas) is switched to flow through the intercooler 81 in its entirety.

FIG. 5 is a block diagram showing a control system for performing control when the engine 1 is started. In FIG. 5, U is a controller (control unit) configured using a microcomputer. The controller U receives signals from various sensors or switches S1 to S6. As described above, the sensor S1 detects the temperature and pressure in the cylinder. The sensor S2 detects the vehicle speed. The sensor S3 detects the accelerator opening as the engine load. The sensor S4 detects the intake air temperature (for example, detects the temperature of the intake air in the surge tank 51). The sensor S5 detects the coolant temperature of the engine 1 (different from the coolant for the intercooler 57). The switch S6 is an engine start switch that is manually operated by the driver. The controller U also has an electric motor 2, clutches 6, 7, 10. Fuel injection valve 38, electric motor 18, EGR valve 82, throttle valve 55, water pump 83. The switching valve 58, the waste gate valve 56e and the like are controlled.

The controller U controls to change the supercharging pressure (maximum supercharging pressure) and the cooling degree (maximum cooling degree) of the intercooler 57 according to the intake air temperature detected by the sensor S4. Basically, when the intake air temperature is low, the supercharging pressure is relatively higher than when it is high, and the degree of cooling by the intercooler 57 is low. The degree of cooling of the intercooler 57 is changed by changing the speed of the circulating cooling water by changing the rotational speed of the water pump 83. Further, the change of the supercharging pressure is performed by both the control of the waste gate valve 56e and the control of the electric supercharger 18. The controller U stores the characteristics shown in FIGS. 4 and 6 as a map in its storage means.

FIG. 6 shows a setting example of the supercharging pressure according to the intake air temperature described above and the cooling water circulation speed (rotation speed of the water pump 83) indicating the cooling degree of the intercooler 57. When the intake air temperature is less than a predetermined temperature T1 (for example, 0 degrees C), the supercharging pressure is set to the maximum value, and the cooling water circulation speed is set to the minimum value (0, the water pump 83 is stopped). Further, when the intake air temperature is higher than a predetermined temperature T2 (temperature 40 to 50 degrees C higher than T1), the supercharging pressure is set to the lowest value, and the coolant circulation speed is set to the highest value. In the range where the intake air temperature is between T1 and T2, the higher the intake air temperature, the lower the supercharging pressure and the higher the cooling water circulation speed.

Here, the supercharging pressure is determined according to, for example, the engine load and the engine speed, and the maximum value of the determined supercharging pressure is set as shown in FIG. In order to keep the electric supercharger 18 paused as much as possible, the insufficient supercharging pressure by the exhaust turbocharger 56 is compensated by driving the electric supercharger 18 (particularly in a transient state). The insufficient supercharging pressure is compensated by the electric supercharger 18 having excellent responsiveness).

The control contents at the time of starting the engine by the controller U will be described with reference to the flowchart of FIG. 7. In the following description, Q indicates a step. First, in Q1, signals from various sensors S1 to S6 are read. Thereafter, in Q2, it is determined whether or not the engine 1 is being started. For example, when the current operation state is in the region A shown in FIG. 4 and in the state close to the region B or the region C, the accelerator opening (or the increase rate) is equal to or greater than a predetermined value. Or when any of the conditions when the starter switch S6 is turned on by the driver's manual operation is satisfied.

When the determination in Q2 is NO, it is determined in Q3 whether or not the engine 1 (cooling water temperature) is colder than a predetermined temperature (for example, 60 degrees C). When the determination in Q4 is NO, in Q4, the switching valve 58 is fully closed and all the intake air flows through the intercooler 57. Next, in Q5, the supercharging pressure and the cooling water circulation speed are determined based on the characteristics shown in FIG. 6 according to the intake air temperature detected by the sensor S4. Thereafter, the wastegate valve 56e and the electric supercharger 18 are controlled so that the supercharging pressure determined in Q5 (within the range) is set, and the water circulation speed is determined so as to achieve the cooling water circulation speed determined in Q5. The pump 83 is controlled.

When YES is determined in Q2 or YES is determined in Q3, the processes of Q7 to Q9 are performed, respectively. That is, in Q7, the switching valve 58 is fully opened, and all the intake air is supplied through the bypass passage 53A (by bypassing the intercooler 57). Next, at Q8, the boost pressure is set to the maximum value shown in FIG. 6 (the maximum boost pressure is set regardless of the intake air temperature). Further, at Q9, the water pump 83 is stopped and the cooling water circulation amount is set to 0 at which the minimum value is reached. By the processing of Q7 to Q9, the control is performed in such a direction that the ignitability and the combustibility are as good as possible, the engine 1 is reliably started, and the warm-up of the engine 1 is promoted.

Although the embodiment has been described above, the present invention is not limited to the embodiment, and can be appropriately changed within the scope described in the scope of claims. For example, the invention includes the following cases. . It may be a case where only one of the electric supercharger 18 and the exhaust turbocharger 56 is provided. A supercharger that is mechanically driven by the engine 1 may be used instead of the exhaust turbocharger 56 or the electric supercharger 18.

When starting the engine is compared after startup (after completion of startup), the weakened cooling degree by the intercooler 57, can also be to enhance the supercharging degree of the electric supercharger 18, in this case, the engine At the time of start-up, the boost pressure may be larger than that shown in FIG. When the engine is started, intake air is supplied through the bypass passage 53A only when the temperature of the cooling water for the intercooler 57 is low. When the temperature of the cooling water is higher than a predetermined temperature, the intake air is supplied through the intercooler 57. You may make it do.

The vehicle may be a vehicle that is not a hybrid vehicle (the electric motor 2 is not for traveling, but is dedicated to starting, for example). In FIG. 1, a transmission mechanism may be interposed between the first clutch 6 and the drive gear 4 (for changing the rotation ratio between the engine 1 and the drive gear 4). Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage.

The present invention can be used, for example, as an intake control method and apparatus for an automatic engine.

1: Engine 2: Electric motor 16L, 16R: Wheel 18: Electric supercharger 33: Combustion chamber 34: Intake port 35: Exhaust port 38: Fuel injection valve 50: Intake passage 53: Common intake passage 53A: Bypass passage 56 : Exhaust turbocharger 56e: Wastegate valve 57: Intercooler (heat exchanger)
58: Switching valve 80: Radiator 83: Water pump U: Controller S2: Sensor (for detecting vehicle speed)
S3: Sensor (for engine load detection)
S4: Sensor (for detecting intake air temperature)
S5: Sensor (for detecting engine coolant temperature)
S6: Switch (for start command)

Claims (6)

An engine in which a supercharger is disposed in an intake passage, a heat exchanger for intake air cooling is provided downstream of the supercharger , and a bypass passage that bypasses the heat exchanger is provided in the intake passage . An intake control method,
A first step of detecting intake air temperature;
A second step of determining the magnitude of the supercharging pressure of the intake air supercharged by the supercharger and the degree of cooling in the heat exchanger according to the intake air temperature detected in the first step;
A third step of controlling the supercharger to be the supercharging pressure determined in the second step and controlling the heat exchanger to be the cooling degree determined in the second step;
With
In the second step, when the intake air temperature is lower than a predetermined temperature, the supercharging pressure is determined as the maximum supercharging pressure, and the intake air supercharged by the supercharger is supplied into the cylinder through the bypass passage. To determine that the degree of cooling by the heat exchanger is minimized,
In the second step, further, at the time of warming up when the intake air temperature is equal to or higher than the predetermined temperature , the boost pressure is maximized as the intake air temperature rises from the predetermined temperature corresponding to the intake air temperature in the same operating state of the engine. Determining to gradually decrease from the supercharging pressure and to gradually increase the cooling degree of the heat exchanger,
An intake control method for an engine. In claim 1,
An intake control method for an engine, wherein the supercharger is an electric supercharger including a compressor wheel disposed in the intake passage and an electric motor for driving the compressor wheel. . In claim 1,
The heat exchanger is set so that refrigerant is circulated and heat is exchanged between the refrigerant and the intake air;
The degree of cooling of the heat exchanger is changed by changing the circulation speed of the refrigerant to the heat exchanger.
An intake control method for an engine. In claim 1,
It is the intake control method for an engine in a hybrid vehicle in which example Bei the engine to perform at least the generator and the electric motor for traveling which drives the wheels,
The supercharge is an electric supercharger;
In the second step, when the engine is started from the engine stop state, the supercharging pressure is determined as the maximum supercharging pressure, and the intake air supercharged by the supercharger is supplied into the cylinder through the bypass passage. By determining so that the degree of cooling by the heat exchanger is minimized,
An intake control method for an engine. An engine in which an electric supercharger is disposed in the intake passage, a heat exchanger for cooling the intake air is provided downstream of the supercharger , and a bypass passage that bypasses the heat exchanger is provided in the intake passage Intake control device of
An intake air temperature detecting means for detecting the intake air temperature;
A controller that receives the output from the intake air temperature detection means and controls the supercharger and the heat exchanger;
With
The controller determines the magnitude of the supercharging pressure of the intake air supercharged by the supercharger and the degree of cooling in the heat exchanger according to the intake air temperature detected by the intake air temperature detecting means, The supercharger is controlled to achieve the determined supercharging pressure, and the heat exchanger is controlled to control the determined cooling degree .
The controller controls so that the supercharging pressure becomes a maximum supercharging pressure when the intake air temperature is lower than a predetermined temperature , and the intake air supercharged by the supercharger enters the cylinder through the bypass passage. By controlling so that the degree of cooling by the heat exchanger is minimized,
The controller further increases the supercharging pressure as the intake air temperature rises from the predetermined temperature corresponding to the intake air temperature in the same operating state of the engine when the intake air temperature is equal to or higher than the predetermined temperature. Control to gradually decrease from the pressure and gradually increase the degree of cooling of the heat exchanger,
An intake control device for an engine. In claim 5,
The controller controls the supercharging pressure to the maximum supercharging pressure when starting the engine from an engine stop state , and supplies the intake air supercharged by the supercharger into the cylinder through the bypass passage. To control the degree of cooling by the heat exchanger to a minimum,
An intake control device for an engine.

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