INTAKE AIR INCREASING DEVICE

The intake increasing device 100 pertaining to the present invention is for increasing air intake of an engine, and is provided with, a cylindrical wall part 20 having an intake inlet 20in and an intake outlet 20out, the wall part 20 leading intake air from the intake air inlet 20in to the intake air outlet 20out, an ejection port 30 for ejecting air F2 flowing along an inner circumferential surface 21 of the wall portion 20 to an air intake downstream side, the ejection port 30 being provided in the wall part 20; and a fan 40 for sending air to the ejection port 30.

TECHNICAL FIELD

The present disclosure relates to an intake increasing device for an engine.

BACKGROUND ART

In general, in an engine mounted on a vehicle or the like, an amount of intake air required for combustion is introduced into the combustion chamber according to a required output. In addition, a large amount of intake air can be fed into the combustion chamber by using a supercharger or the like to increase the output.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, for example, in places where the atmospheric pressure is low, such as high altitudes, since the oxygen concentration in the air is low, it may not be possible to ensure a required amount of intake air even when a supercharger or the like is used. In this case, the engine output is reduced and the fuel efficiency deteriorates.

In particular, in an operating state in which an engine speed is low, the supercharger or the like may not operate efficiently. For this reason, for example, when the vehicle starts, the engine output may be reduced, and the startability may deteriorate.

Therefore, in order to solve the above-mentioned problems, an object of the present disclosure is to provide an intake increasing device capable of ensuring a required amount of intake air and suppressing output reduction regardless of an operating environment and an operating state of an engine.

Solution to Problem

According to one aspect of the present disclosure, there is provided an intake increasing device for increasing intake of an engine, which includes a cylindrical wall part which includes an intake inlet and an intake outlet and guides intake air from the intake inlet to the intake outlet, a ejection port for ejecting air flowing toward an intake downstream side along an inner circumferential surface of the wall portion, and a fan for sending air to the ejection port.

A cross-sectional shape of the inner circumferential surface of the wall portion preferably approximates to a cross-sectional shape of a blade upper surface.

Preferably, the inner circumferential surface of the wall portion includes a reduced diameter portion which is gradually reduced in diameter in a round cross-sectional shape from the intake inlet, and an enlarged diameter portion which smoothly connects to the reduced diameter portion and is gradually enlarged, and the ejection port is positioned on the reduced diameter portion and is directed toward the intake downstream side.

The ejection port preferably extends in a peripheral direction of the wall portion.

It is preferable that the engine is mounted on a vehicle and the intake increasing device further includes a control unit for controlling the fan and an accelerator opening sensor for detecting an accelerator opening, in which the control unit operates the fan when the first condition that the detection value of the accelerator opening sensor is larger than the first threshold value is satisfied.

It is preferable that the intake increasing device further includes an atmospheric pressure sensor for detecting atmospheric pressure and an engine rotation sensor for detecting the engine speed, in which the control unit operates the fan when the first condition is satisfied and at least one of a second condition in which a detection value of the atmospheric pressure sensor is equal to or less than a second threshold value and a third condition that the detection value of the engine rotation sensor is equal to or less than a third threshold value is satisfied.

It is preferable that the engine includes a supercharger, the intake increasing device further includes an atmospheric pressure sensor for detecting atmospheric pressure, an engine rotation sensor for detecting the engine speed, and a supercharging pressure sensor for detecting the supercharging pressure, in which the control unit operates the fan when the first condition is satisfied and at least one of the second condition in which a detection value of the atmospheric pressure sensor is equal to or less than the second threshold value and a fourth condition that the engine operating state defined based on a detection value of the engine rotation sensor and a detection value of the supercharging pressure sensor is in a predetermined supercharging insufficient state is satisfied.

It is preferable that the engine is mounted on a vehicle including a cab, and the wall portion is formed in a flat cross section, and is disposed along a rear surface of the cab such that the intake inlet opens upward, the intake outlet opens downward, and the longitudinal direction of the cross section thereof coincides with the vehicle width direction.

It is preferable that the engine includes an air cleaner and an intake duct connected to an inlet portion of the air cleaner, and the wall portion is connected to an inlet portion of the intake duct, the inlet portion of the intake duct is formed in a flat cross section, and the intake outlet is connected to an inlet of the intake duct.

Advantageous Effects of Invention

According to the present disclosure, an intake increasing device can be provided which is capable of ensuring a required amount of intake air and suppressing output reduction regardless of the use environment and the operating state of the engine.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure will be described below with reference to the accompanying drawings. Although directions shown in the drawings are merely defined for convenience of description, the directions are assumed to coincide with the respective directions of the vehicle.

(1) First Embodiment

FIG. 1is a schematic configuration view showing a vehicle1to which an intake increasing device100according to a first embodiment of the present disclosure is applied. Further,FIG. 2is a schematic perspective view showing an overall configuration of the intake increasing device100, andFIG. 3is a cross-sectional view taken along line III-III inFIG. 2. Further,FIG. 4is a cross-sectional view taken along line IV-IV inFIG. 3, andFIG. 5is an enlarged view of a portion V inFIG. 4. A white arrow F1shown inFIGS. 2 to 5represents intake air. A black arrow F2shown inFIGS. 4 and 5represents the air (described later) ejected from an ejection port30.

As shown inFIGS. 1 and 2, the intake increasing device100is an intake increasing device for increasing the intake air F1of the engine10. As shown inFIGS. 3 to 5, the intake increasing device100includes a tubular body20including an intake inlet20in and an intake outlet20out and leading the intake air F1from the intake inlet20in to the intake outlet20out. The intake increasing device100includes a ejection port30which is provided in the tubular body20and ejects air F2flowing toward the intake downstream side along an inner circumferential surface21of the tubular body20, and a fan40for sending the air F2to the ejection port30. Further, the intake increasing device100includes an electronic control unit (ECU)50as a control unit for controlling the fan40.

The intake increasing device100further includes an accelerator opening sensor51for detecting an accelerator opening. The intake increasing device100further includes an atmospheric pressure sensor52for detecting an atmospheric pressure and an engine rotation sensor53for detecting the engine speed. The intake increasing device100further includes an supercharging pressure sensor54for detecting the supercharging pressure. However, in the present embodiment, the supercharging pressure sensor54may be optional.

Specifically, as shown inFIG. 1, the engine10is a multi-cylinder compression-ignition internal combustion engine mounted on the vehicle1, that is, a diesel engine. However, the type, the form, the number of cylinders, and the like of the engine10are optional.

The vehicle1is a cab-over type truck, and includes a cab2, an engine10disposed in a lower portion of the cab2, a chassis frame3for supporting the cab2, and a bodywork4disposed at the rear of the cab2. Reference numeral5denotes a front wheel of the vehicle1.

As shown inFIG. 2, the engine10includes an engine body11including a plurality of combustion chambers (not shown), an intake manifold12for distributing intake air F1into each combustion chamber, and an intake pipe13connected to an upstream end of the intake manifold12. In addition, the engine10includes a turbocharger (not shown) as a supercharger. A turbocharger compressor (not shown) is provided in the middle of the intake pipe13.

As shown inFIGS. 2 and 3, the engine10includes an air cleaner14and an intake duct15connected to an inlet portion14aof the air cleaner14. The outlet portion14bof the air cleaner14is connected to an upstream end of the intake pipe13. These connecting portions are connected to each other by a spigot joint fitting, and are fixed to each other by a metal band B. However, the connection method may be any method.

The air cleaner14includes a case14chaving the inlet portion14aand the outlet portion14b,and a cylindrical air filter14daccommodated in the case14c.However, the air filter14dmay be of any type. The air cleaner14is disposed on the right rear side of the engine body11, and the inlet portion14ais opened rearward.

As shown inFIGS. 1 to 3, the intake duct15extends rearward from the inlet portion14aof the air cleaner14and is bent upward at a position of a lower end of the rear surface2aof the cab2. An inlet portion15aof the intake duct15is formed in a flat cross section, opens upward, and is disposed such that the longitudinal direction of the cross section thereof coincides with the vehicle width direction (the left-right direction in the drawing).

The tubular body20is connected to the inlet portion15aof the intake duct15. More specifically, the tubular body20is formed in a flat cross section and is disposed along the rear surface2aof the cab2such that the intake inlet20in opens upward, the intake outlet20out opens downward, and the longitudinal direction of the cross section of thereof coincides with the vehicle width direction.

The intake outlet20out is connected to an inlet15in of the intake duct15. A cover member60for preventing foreign substances from entering from above is connected to the intake inlet20in.

The cover member60includes an inlet portion60aas an inlet and an outlet portion60bconnected to an upstream end portion of the tubular body20. The cover member60is formed in a flat cross section and extends upward from the outlet portion60band extends rightward along the rear surface2aof the cab2. The inlet portion60ais opened downward at the bottom portion of the extended portion.

As shown inFIG. 1, the rear surface2aof the cab2may be provided with a recessed portion C at left and right positions thereof. The tubular body20and the cover member60may be disposed so as to fit in the recessed portions C.

Next, the configurations of the tubular body20, the ejection port30, and the fan40will be described in detail with reference toFIGS. 4 and 5.

As shown inFIGS. 4 and 5, in the flow direction of the intake air F1, the intake inlet20in is positioned at the upstream end of the tubular body20, and the intake outlet20out is positioned at the downstream end of the tubular body20.

The tubular body20includes an upstream spigot fitting portion22aformed over the entire periphery at an upstream end portion thereof, and a downstream spigot fitting portion22bformed over the entire periphery at the downstream end portion thereof in the flow direction of the intake air F1. The upstream spigot fitting portion22ais connected to the outlet portion60bof the cover member60by spigot fitting, and the upstream spigot fitting portion22aand the outlet portion60bare fixed to each other by the metal band B. The downstream spigot fitting portion22bis connected to the inlet portion15aof the intake duct15by spigot fitting, and the downstream spigot fitting portion22band the inlet portion15aare fixed to each other by the metal band B. However, these connection methods may be any method.

The inner circumferential surface21of the tubular body20has a cross-sectional shape approximating the cross-sectional shape of the blade upper surface. Specifically, the inner circumferential surface21of the tubular body20includes a reduced diameter portion20agradually reduced in diameter from the intake inlet20in to a round cross-sectional shape, and an enlarged diameter portion20bsmoothly connected to the reduced diameter portion20aand gradually enlarged in diameter. The ejection port30is positioned in the reduced diameter portion20aand is directed toward the intake downstream side. The ejection port30extends in the peripheral direction of the tubular body20, and extends over the entire periphery.

More specifically, the reduced diameter portion20ais reduced in diameter so as to expand radially inward from the intake inlet20in in the flow direction of the intake air F1. The reduced diameter portion20ais reduced in diameter from the intake inlet20in to the ejection port30in a round cross-sectional shape having a predetermined radius of curvature R. On the other hand, the enlarged diameter portion20bis enlarged in diameter so as to extend in a round or straight line up to the downstream end of the tubular body20in the flow direction of the intake air F1. The connection portion between the reduced diameter portion20aand the enlarged diameter portion20bis formed in a round cross-sectional shape.

A space31(not shown) that extends from the upstream end to the downstream end and communicates with the ejection port30at the position of the reduced diameter portion20ais formed inside the tubular body20. The space31is formed over the entire periphery of the tubular body20. A curved surface portion23having a round cross-sectional shape facing the space31is formed at an upstream end portion of the tubular body20. Further, the tubular body20includes an inner wall portion24defined radially inward and an outer wall portion25defined radially outward with the space31in between.

The ejection port30is formed by cutting the inner wall portion24over the entire periphery, and is formed in a slit shape by an upstream side cutting end portion32and a downstream side cutting end portion33. The upstream side cutting end portion32is formed to be sharp toward the intake downstream side. On the other hand, the downstream side cutting end portion33is bent or curved so as to be positioned radially outward with respect to the upstream side cutting end portion32.

The downstream side cutting end portion33includes a tongue piece portion34that is curved in a tongue-like shape. A tip end portion of the tongue piece portion34is formed in a round cross-sectional shape. However, the shape of the tip end portion of the tongue piece portion34is optional, and may be formed in a sharp shape, for example.

The tongue piece portion34is disposed so as to overlap with the upstream side cutting end portion32and guides the air F2from the space31to the ejection port30. In addition, in the flow direction of the air F2, the tongue piece portion34is disposed such that a distance from the upstream side cutting end portion32is gradually reduced, and is formed such that the ejection port30is in a nozzle shape.

The outer wall potion25includes an outer peripheral surface25aextending linearly from the upstream end portion to the downstream end portion in the flow direction of the intake air F1. The outer wall portion25includes a circular opening portion26on the left side surface. The outer wall portion25is provided with a tubular fan attachment portion27protruding leftward from the opening portion26.

The fan attachment portion27includes an air inlet27in at a left end portion for taking in outside air. A fan cover (not shown) capable of passing outside air is attached to the air inlet27in.

The fan40includes an axial flow fan and includes a motor40mas a power source. The fan40is disposed coaxially within the fan attachment portion27and is disposed so as to eject the air F2toward the space31. The type of the fan is optional, and may be, for example, a mixed-flow fan.

The motor40mis fixed to the inner wall27aof the fan attachment portion27via a support member (not shown). The motor40mis electrically connected to an ECU50.

The ECU50includes a CPU, a ROM, a RAM, a memory device, an input/output port, and the like. The ECU50is electrically connected with various sensors such as an accelerator opening sensor51, an atmospheric pressure sensor52, an engine rotation sensor53, and a supercharging pressure sensor54.

FIG. 6is a flowchart showing the control of the ECU50according to the present embodiment.

For example, while the ignition switch (not shown) of the vehicle1is ON, the ECU50repeatedly executes the control flow inFIG. 6every predetermined calculation period (for example, 10 ms).

In step S101, the ECU50acquires the detection value Ac of the accelerator opening sensor51, the detection value Pa of the atmospheric pressure sensor52, and the detection value Ne of the engine rotation sensor53.

In step S102, the ECU50determines whether the first condition (Ac>0%) in which the detection value Ac of the accelerator opening sensor51is larger than a threshold value (0% in this case) is satisfied. When it is determined in step S102that the first condition (Ac>0%) is satisfied (YES), the ECU50proceeds to step S103and determines whether or not the second condition (Pa≤Pas) in which the detection value Pa of the atmospheric pressure sensor52is equal to or less than the threshold Pas.

On the other hand, when it is determined in step S102that the first condition (Ac>0%) is not satisfied (NO), the ECU50proceeds to step S104, executes control (OFF) that does not operate the fan40by stopping the motor40m,and returns.

When it is determined in step S103that the second condition (Pa≤Pas) is satisfied (YES), the ECU50proceeds to step S105, executes control (ON) for operating the fan40by driving the motor40m,and returns.

When it is determined in step S103that the second condition (Pa≤Pas) is not satisfied (NO), the ECU50proceeds to step S106and determines whether or not the third condition (Ne≤Nes) in which the detection value Ne of the engine rotation sensor53is equal to or less than the threshold Nes is satisfied. When it is determined in step S106that the third condition (Ne≤Nes) is satisfied (YES), the ECU50proceeds to step S105, executes control (ON) for operating the fan40by driving the motor40m,and returns.

On the other hand, when it is determined in step S106that the third condition (Ne≤Nes) is not satisfied (NO), the ECU50proceeds to step S104to execute control (OFF) that does not operate the fan40by stopping the motor40m,and returns.

In this way, the ECU50of the present embodiment operates the fan40when the first condition (Ac>0%) is satisfied and at least one of the second condition (Pa≤Pas) and the third condition (Ne≤Nes) is satisfied. On the other hand, when the first condition is not satisfied or at least one of the second condition and the third condition is not satisfied, the ECU50does not operate the fan40.

Next, the operation and effect of the intake increasing device100according to the present embodiment will be described with reference toFIGS. 1 to 6.

In the engine10, basically, an amount of intake air F1required for combustion is introduced into the combustion chamber of the engine body11according to a required output such as acceleration or deceleration of the vehicle1.

Specifically, during operation of the engine10, the intake air F1is introduced into the cover member60from the atmosphere, sequentially passes through the tubular body20, the intake duct15, the air cleaner14, the intake pipe13, and the turbocharger compressor, the intake pipe13and the intake manifold12, and is introduced into the combustion chamber.

Further, the intake air F1is supercharged by the turbocharger compressor, and is thus fed into the combustion chamber in a large amount. As a result, the engine output can be increased.

In the present embodiment, the ECU50executes control to operate the fan40when the first condition (Ac>0%) is satisfied and at least one of the second condition (Pa≤Pas) and the third condition (Ne≤Nes) is satisfied. When the fan40is operated, in the tubular body20, the air F2is sent to the ejection port30and is ejected from the ejection port30toward the intake downstream side.

As shown inFIGS. 4 and 5, the ejected air F2flows from the downstream cutting end portion33of the inner wall portion24to the intake downstream side along the inner circumferential surface21by the Coanda effect, and draws the intake air F1passing through the radially inner side of the inner wall portion24. By this operation, the intake air F1is accelerated, so that the intake air F1can be increased.

In particular, the reduced diameter portion20aof the tubular body20is reduced in diameter from the intake inlet20in to the ejection port30in a round cross-sectional shape having a predetermined radius of curvature R. Thus, the intake air F1can be smoothly introduced into the intake inlet20in along the cross-sectional shape.

The curved surface portion23having a round cross-sectional shape facing the space31is formed at the upstream end portion of the tubular body20, and the ejection port30is directed toward the intake downstream side. Thus, the air F2introduced into the space31from the fan40can be smoothly changed in the direction along the curved surface portion23, and the air F2can be ejected from the ejection port30in a desired direction in the intake air downstream direction.

In addition, since the ejection port30is formed in a slit shape over the entire periphery of the inner wall portion24, the air F2can be uniformly ejected in the entire periphery. Further, since the ejection port30is formed in a nozzle shape, the air F2can be accelerated and ejected.

In this way, with the above configuration, the effect of flowing the intake air F1along the inner circumferential surface21can be increased to the maximum, and the intake air F1can be further increased. The ejection port30may not be formed over the entire periphery of the inner wall portion24.

Although not shown, a vehicle to which the intake increasing device100is not applied will be discussed as a comparative example.

In this case, for example, since the oxygen concentration in the air is low at places where the atmospheric pressure is low, such as a highland, there is a possibility that an amount of intake air required for combustion cannot be secured even if supercharging is performed by a turbocharger and the like. For this reason, for example, compared to a place where the oxygen concentration in the air is higher than that of a highland and the like, the engine output is reduced, and the fuel efficiency may be deteriorated.

In addition, for example, there is a possibility that a difference in output may occur due to a difference in the use environment of the engine, such as a decrease in the acceleration performance of the vehicle at a highland compared to a lowland. Therefore, the driving performance of the vehicle may be deteriorated.

In particular, in an operating state in which the engine speed is low, the turbocharger may not operate efficiently. Therefore, there is a possibility that a problem such as deterioration of the startability may occur due to engine output reduction.

As means for solving these problems, it is conceivable to use a turbocharger that is set to operate efficiently at places where the atmospheric pressure is low or in an operation state in which the engine rotation speed is low (hereinafter, referred to as an “intake shortage state”). However, in this turbocharger, when the engine is not in the intake shortage state, the supercharging efficiency is reduced, and the engine output may be reduced during running other than a highland or starting time.

The intake increasing device100of the present embodiment increases the intake air F1when the detection value Pa of the atmospheric pressure sensor52is equal to or less than the threshold value Pas. Thus, in a place where the atmospheric pressure is low, the engine output can be increased, and as a result, the fuel efficiency can be improved. In addition, since the output difference due to the use environment of the engine10can be reduced, the operability of the vehicle1can be improved.

The intake increasing device100increases the intake air F1when the detection value Ne of the engine rotation sensor53is equal to or less than the threshold Nes. Thus, in the low rotation range of the engine in which the turbocharger does not operate efficiently, the increased intake air F1is introduced into the compressor to increase the supercharging pressure and the decrease in the engine output can be suppressed. Then, the startability of the vehicle1can be improved.

Further, according to the intake air increasing device100, when the intake air is in the intake shortage state, the supercharging pressure of the turbocharger is increased by increasing the intake air F1, and when the intake air is not in the intake shortage state, the supercharging pressure of the turbocharger can be efficiently increased only with the turbocharger without increasing the intake air F1.

As described above, in the present embodiment, regardless of the use environment and the operating state of the engine10, a required amount of intake air can be ensured and output reduction can be suppressed, and the fuel efficiency, the startability, and the like can be improved.

In addition, in the present embodiment, the following operations and effects exist in addition to the above.

Although not shown, for example, it is assumed that an ejecting nozzle or a fan for ejecting air to the intake downstream side is disposed radially inward of the inner circumferential surface of the tubular body. In the case, an ejecting nozzle and the like may be an obstacle to intake air, which may hinder an increase in intake air.

In contrast, in the present embodiment, since the ejection port30is provided on the inner circumferential surface21of the tubular body20and there is no obstacle on the radially inner side of the inner circumferential surface21, the intake air F1can be efficiently increased without generating the intake resistance.

Although not shown, for example, when the tubular body20is formed in a circular cross section, for example, when the gap between the rear surface of the cab and the bodywork is small, only a tubular body having a small diameter can be used. Therefore, the passage area in the tubular body is reduced, and the intake air amount is limited.

In contrast, in the present embodiment, as shown inFIGS. 1 and 2, the tubular body20is formed in a flat cross section and is disposed along the rear surface2aof the cab2such that the longitudinal direction of the cross section thereof coincides with the vehicle width direction. Therefore, even when the gap between the rear surface2aof the cab2and the bodywork4is small, the passage area in the tubular body20can be increased, which is advantageous in increasing the intake air amount.

In particular, as shown inFIG. 1, there is a case where there is little gap between the center portion of the rear surface2aof the cab2protruding rearward and the bodywork4in the cab-over type truck. A recessed portion C having a short front-rear length may be formed on the right side of the central portion of the rear surface2a.

In the present embodiment, the tubular body20is formed in a flat cross section, and is disposed in the recessed portion C together with the cover member60. Therefore, the tubular body20having a large passage area can be disposed.

On the other hand, in the control of the present embodiment, the ECU50determines that the driver has an intention to accelerate when the first condition (Ac>0%) is satisfied, and operates the fan40when the second condition (Pa≤Pas) or the third condition (Ne≤Nes) is satisfied. When the first condition (Ac>0%) is not satisfied, the ECU50does not operate the fan40as the driver does not intend to accelerate. Therefore, the fan40can be efficiently operated by determining whether or not the driver has an intention to accelerate.

(2) Second Embodiment

FIG. 7is a schematic perspective view showing an overall configuration of an intake increasing device100′ according to a second embodiment of the present disclosure. Further,FIG. 8is a cross-sectional view taken along line VIII-VIII inFIG. 7, andFIG. 9is a cross-sectional view taken along line IX-IX inFIG. 8. In the following description, the same components as those of the first embodiment are denoted by the same reference numerals, and the components corresponding to those in the first embodiment are denoted by the reference numerals with the symbol “′”, and detailed description thereof will be omitted.

As shown inFIGS. 7 and 8, in the second embodiment, the air cleaner14′ is disposed on the left front side of the engine body11, and the intake duct15′ is disposed so as to extend forward from the inlet portion14a′ of the air cleaner14′. The inlet portion15a′ of the intake duct15′ is formed in a circular cross section and opens forward.

The tubular body20′ includes a circular cross section and is connected to an inlet15a′ of the intake duct15′. The tubular body20′ is disposed below the left front portion of the cab2, and the intake inlet20in′ is disposed so as to open forward. The intake outlet20out′ is connected to the inlet15in′ of the intake duct15′.

The cover member60as in the first embodiment is not connected to the intake inlet20in′ of the tubular body20′. Therefore, as indicated by the shaded arrow inFIG. 9, the intake air f can be introduced directly into the intake inlet20in′ from the outside in the radial direction of the tubular body20′.

In particular, at the upstream end of the tubular body20′, as shown inFIG. 9, an end surface28having a round cross-sectional shape is formed from the intake inlet20in′ to the outer peripheral surface25a′ of the outer wall portion25′. Accordingly, the intake air f can be smoothly introduced from the outside along the end surface28.

The intake air f introduced into the intake inlet20in′ is ejected from the ejection port30′ and is attracted to the air F2flowing along the inner circumferential surface21′ of the inner wall portion24′, and is accelerated together with the intake air F1introduced from the front. As a result, the intake air increasing device100′ of the second embodiment can obtain a larger amount of intake air than that of the first embodiment.

FIG. 10is a flowchart showing the control of the ECU50according to a third embodiment of the present disclosure. Further,FIG. 11is a map M showing a relationship between the engine speed and the supercharging pressure. The third embodiment can be applied to at least one of the above-described first and second embodiments.

As shown inFIG. 10, the ECU50of the third embodiment refers to the map M and determines whether or not a fourth condition (engine operating state=ON region) in which the engine operating state is a predetermined supercharging insufficient state is satisfied, instead of the third condition (Ne≤Nes) described in the first embodiment.

Here, the “engine operating state” means an operating state defined based on the detection value Ne of the engine rotation sensor53and the detection value Pt of the supercharging pressure sensor54. Further, the “predetermined supercharging insufficient state” means an operation state in which the supercharging pressure of the turbocharger compressor is insufficient.

As shown inFIG. 11, the map M defines the relationship between the engine speed and the threshold value Pts of the supercharging pressure corresponding to the engine speed.

More specifically, in the map M, a region below the threshold value Pts is in supercharging insufficient state, and is set to an ON region where the fan40is operated. On the other hand, the region that is equal to or more than the threshold value Pts is not in a supercharging insufficient state, and is set to an OFF region in which the fan40is not operated.

By referring to the map M, the ECU50determines that the detection value Pt of the supercharging pressure sensor54is in the ON region when the detection value Pt of the supercharging pressure sensor54is less than the threshold value Pts of the supercharging pressure corresponding to the detection value Ne of the engine rotation sensor53. On the contrary, when the detection value Pt of the supercharging pressure sensor54is equal to or more than the threshold value Pts of the supercharging pressure corresponding to the detection value Ne of the engine rotation sensor53, it is determined that the detection value Pt of the supercharging pressure sensor54is not in the ON region.

Specifically, as shown inFIG. 10, in step S101′, the ECU50acquires the detection value Pt of the supercharging pressure sensor54together with the detection value Ac of the accelerator opening sensor51, the detection value Pa of the atmospheric pressure sensor52, and the detection value Ne of the engine rotation sensor53.

When it is determined in step S103that the second condition (Pa≤Pas) is not satisfied (NO), the ECU50proceeds to step S107and refers to the map M. Then, the ECU50proceeds to step S108to determine whether or not the fourth condition (engine operating state=ON region) is satisfied.

When it is determined in step S108that the fourth condition (engine operating state=ON region) is satisfied (YES), the ECU50proceeds to step S105to execute control (ON) for operating the fan40by driving the motor40m,and returns.

On the other hand, when it is determined in step S108that the fourth condition (engine operating state=ON region) is not satisfied (NO), the ECU50proceeds to step S104to execute control (OFF) that does not operate the fan40by stopping the motor40m,and returns.

According to the above control, even when the engine speed is low, the ECU50cannot operate the fan40when the supercharging pressure required for combustion is obtained. In contrast, even when the engine speed is high, the fan40can be operated when the supercharging pressure required for combustion is not obtained.

Therefore, since the intake air F1can be increased in consideration of not only the engine speed Ne but also the supercharging pressure Pt, output reduction can be suppressed with higher accuracy.

Additionally, the present disclosure is not limited to the embodiments described above, and can be appropriately modified and implemented without departing from the spirit of the present disclosure. Although not shown, for example, the above-described embodiments can be modified as follows.

First Modified Embodiment

With regard to the control of the ECU50, the first to fourth conditions may be combined optionally.

For example, the ECU50may determine only the first condition without determining the second, third or fourth conditions, and operate the fan40when the first condition is satisfied (Ac>0%). According to this control, when the accelerator opening Ac is larger than 0%, the intake air F1is always increased to improve the engine output.

Further, the fan40may be operated when the third condition (Ne≤Nes) or the fourth condition (engine operating state=ON region) is satisfied without providing the second condition (Pa≤Pas). Further, the fan40may be operated when the second condition (Pa≤Pas) is satisfied without providing the third condition (Ne≤Nes) or the fourth condition (engine operating state=ON region). Further, the fan40may be operated constantly during operation of the engine or during running of the vehicle without providing any conditions.

Second Modified Embodiment

The ECU50may control the rotation speed of the fan40corresponding to the detection value Ac of the atmospheric pressure sensor52and the detection value Ne of the engine rotation sensor53.

For example, the ECU50may control the rotation speed of the fan40to be higher as the detection value Ac of the atmospheric pressure sensor52is lower with reference to a predetermined map defining the relationship between the atmospheric pressure and the rotation speed of the fan40.

The ECU50may control the rotation speed of the fan40to be higher as the detection value Ne of the engine rotation sensor53is lower with reference to the predetermined map defining the relationship between the engine speed and the rotation speed of the fan40.

Further, the ECU50may control the rotation speed of the fan40to be higher as the atmospheric pressure and the engine speed are lower, for example, with reference to the predetermined map defining the relationship among the atmospheric pressure, the engine speed, and the rotation speed of the fan40.

According to these controls, the intake air F1can be increased with higher accuracy corresponding to the use environment and the operating state of the engine.

Third Modified Embodiment

In the first embodiment, the inlet portion15aof the intake duct15′, the tubular body20, and the cover member60have flat cross sections, and in the second embodiment, the inlet portion15a′ of the intake duct15′ and the tubular body20′ have circular cross sections, but these cross-sectional shapes may be optional. That is, these cross-sectional shapes can be freely changed, for example, corresponding to the layout of the vehicle1.

Fourth Modified Embodiment

In the tubular body20,20′, the opening portion26and the fan attachment portion27may have any shape or orientation. For example, the opening portion26may be formed on the right side surface of the outer wall portion25, and the fan attachment portion27may be provided so as to protrude rightward.

In the fan attachment portion27, the direction of the air inlet27in may be optional. For example, inFIG. 2, the air inlet27in may be opened downward at the position of the left end portion of the fan attachment portion27.

This application is based on the Japanese Patent Application No. 2017-074595 filed on Apr. 4, 2017, the contents of which are incorporated herein as reference.

INDUSTRIAL APPLICABILITY

The intake increasing device of the present disclosure is useful in that a required amount of intake air can be ensured, and the output reduction can be suppressed regardless of the use environment and the operating state of the engine.

REFERENCE SIGNS LIST