JPH03524A - Suction system for engine - Google Patents

Abstract

PURPOSE:To supply a sufficient amount of intake air of low temperature with high responsiveness by providing a communication passage and a valve means which communicate a cooling duct with an intake duct in operating conditions where high output power is required. CONSTITUTION:An intake duct 10 is equipped with a communication passage 18 connected with the inside of a cooler duct 60 and with a switch-over valve 81 which opens/closes the passage, and the valve 81 is controlled to be opened/ closed by a controller 80 in response to the opening conditions of an engine through an actuator 82. When an engine is out of an accelerating condition, and moreover is out of high loading and a high speed range, the communication passage 18 is interrupted with the switch-over valve 81 closed, intake air is taken from the intake port at the tip end of the intake duct 10 so that it is supplied to the engine. When the engine is required to output high power, the communication passage 81 is opened with the switch-over valve 81 set up at an open condition so that running air introduced from a radiator duct to the cooler duct 60 is thereby supplied to the engine from the intake duct 10 through an air cleaner, an exhaust turbo supercharger and an inter cooler.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an engine intake system, particularly an engine intake system in a vehicle that is provided with a cooling duct in the engine room that guides running air to a cooling device such as an intercooler. Regarding.

(Prior Art) In general, an intake duct that is included in an engine and supplies intake air to a combustion chamber has a diameter based on a throttle section provided in the duct so that intake air can be introduced most efficiently under normal operating conditions. is set, and therefore it is customary to have a relatively elongated shape.

On the other hand, in engines with exhaust turbo superchargers, etc., the intake system may be equipped with an intercooler that cools the intake air.
As shown in Japanese Patent No. 3-58030, an air-cooled type in which intake air is cooled by running wind introduced toward the intercooler is often adopted. In this case, the duct that introduces the running wind has a large passage cross-sectional area unlike the above-mentioned intake duct because it is necessary to introduce a large amount of air, and moreover, the duct that introduces the running wind is set to have a larger passage cross-sectional area than the above-mentioned intake duct. configured to deploy.

(Problem to be Solved by the Invention) By the way, as mentioned above, the intake duct is set to have a relatively small diameter so that intake air is most efficiently supplied under normal operating conditions. If this is done alone, it may not be possible to supply the required amount of intake air to the engine in a responsive manner, especially when high output is required, such as during sudden acceleration. One possible solution to this problem is to install an auxiliary duct in addition to the normal intake duct that introduces intake air only when high output is required. This is becoming difficult to achieve due to the trend towards lower bonnets in Japan.

Therefore, the present invention provides that when a cooling duct is provided in the engine room to introduce running air for the intercooler, etc., by using this duct, a sufficient amount of air can be generated when high output is required. Moreover, the challenge was to be able to supply low-temperature intake air from outside the engine room in a responsive manner, and at the same time, actively transmit sporty engine intake noise into the passenger compartment during acceleration, creating a comfortable driving feeling. The challenge is to provide this to the crew.

(Means for Solving the Problems) In order to solve the above problems, the present invention is characterized by having the following configuration.

That is, the engine intake system according to the present invention includes, in an engine room, an intake duct that supplies intake air to the engine, and a cooling duct that guides running air as cooling air to a cooling device installed in the engine room. In the vehicle equipped with the above-mentioned vehicle, a communication passage is provided that communicates the cooling duct with the downstream side of the inlet opening end of the intake duct, and the communication passage is used to connect the cooling duct with the intake air in a specific operating state where high engine output is required. It is characterized by providing a valve means communicating with the duct.

(Function) According to the above configuration, under normal operating conditions, intake air is taken in from the inflow opening end of the intake duct, is efficiently supplied to the engine through the duct, and high output is required. In certain driving conditions, such as during acceleration,
Since the valve means provided in the communication passage that communicates the intake duct and the cooling duct communicates the cooling duct and the intake duct, the traveling wind introduced into the cooling duct flows from the duct to the downstream of the communication passage and the intake duct. The air is then supplied to the engine as intake air. As a result, when a high output is required, a large amount of low-temperature intake air taken in from outside the engine room is supplied to the engine with high dynamic pressure with good responsiveness, and a high output corresponding to the demand can be obtained.

In addition, when the intake duct and the cooling duct communicate with each other during acceleration, the engine intake noise generated in the intake duct propagates into the cooling duct, and also passes through the cooling device to the rear passenger compartment side. It will be released towards.

This intake noise then reaches the ears of the occupants inside the vehicle, giving them a comfortable driving experience.

(Example) Examples of the present invention will be described below.

First, the overall configuration of the intake system of the engine 1 according to the present embodiment will be explained with reference to FIG.
an air cleaner 20 that is introduced from the exhaust gas, an exhaust turbo supercharger 30 that pressurizes intake air using the energy of exhaust gas;
It is composed of an intercooler 40 that cools this pressurized intake air. The intake air introduced through these is supplied to each combustion chamber of the engine 1 via the throttle valve 2.

As shown in FIGS. 1 and 2, the intake duct 10 is arranged above the front part of the engine room 3 so as to extend in the width direction of the vehicle body. The disposed first cross member 4 includes a flange portion 11 provided at the left end in the drawing, and brackets 12 and 13 provided at the right end and center portion.
Fixed in place. Further, this intake duct 10 is provided with an intake port 14 opening toward the front at the left end, and furthermore, an oval intake outlet 15 is provided at the bottom of the right end.

Further, as shown in FIGS. 1 and 3, the air cleaner 20 is disposed immediately behind the right end of the intake duct 10, and is disposed in the center of the engine room 3 in the width direction of the vehicle body. Brackets 21, 22.
It is fixed via 23. As shown in FIG. 3, the cleaner 20 is composed of an upper case 24 and a lower case 25, and a connecting pipe part 26 is protruded from the front surface of the lower case 25. 26 is connected to a connecting pipe portion 16 that protrudes downward from the intake outlet 15 of the intake duct 10, so that intake air is introduced from the intake duct 10 into the air cleaner 20. .

Further, the intercooler 40 into which intake air is introduced from the air cleaner 20 through the passage 51, the exhaust turbo supercharger 30, and the passage 52, as shown in FIGS. 1 and 2,
The front part is supported by the first cross member 4 via a bracket 41 arranged in the center of the engine room 3 immediately behind the intake duct 10 and arranged below the duct 10 in the front-rear direction. , the rear portion is supported by the second cross member 5 via brackets 42 and 43. Further, this intercooler 40 is composed of upper and lower tank parts 44.45 and a heat exchange part 46 between them, and an intake inlet 47 and an intake outlet on the rear surfaces of both tank parts 44.45. 48 are provided respectively, and the intake inlet 47 is connected to the exhaust turbocharger 3 via the passage 52.
0, and the intake outlet 48 is connected to the throttle valve 2 via a passage 53, respectively. The intercooler 40 is of an air-cooled type that cools intake air using running wind when the vehicle is running, and is provided with a cooler duct 60 that guides cooling air to the cooler 40.

As shown in FIG. 2, this cooler duct 60 has an upper portion fixed to a bracket 41 that supports the intercooler 40 on the first cross member 4, and a rear end portion fixed to the intercooler 40 via the bracket 61. ing. The air inlet 62 at the front end opens into a radiator duct 71 that introduces cooling air into the radiator 70 from an air intake lower provided at the lower part of the front end of the vehicle body, and the rear end opens into a heat exchange section in the intercooler 40. 46
is opened facing the front surface of the intercooler 40, so that a part of the running air introduced into the radiator duct 71 passes through the inside of the cooler duct 60 and reaches the heat exchange section 46 of the intercooler 40.
is being supplied to.

Here, this cooler duct 60 is set to have a sufficiently large passage cross-sectional area so as to sufficiently introduce running wind, and in this embodiment, the inside is divided into left and right passages 64 and 65 by a partition wall 63. has been done.

In addition to the above configuration, this intake device is provided with a communication passage that allows the intake duct 10 and the cooler duct 60 to communicate with each other. That is, as shown in FIGS. 4 and 5, an opening 17 is provided in the middle lower surface of the intake duct 10, and a communication path 18 extending downward is provided in the opening 17. The communication passage 18 passes through the upper surface of the cooler duct 60 and enters the passage 65 on the right Φ side of the cooler duct 60. A switching valve 81 is swingably provided inside the opening 17 of the intake duct 10, and on the lower surface of the eaves section 19 provided along the rear edge of the upper surface of the intake duct 10. An actuator 82 of the switching valve 81 is attached, and when the actuator 82 operates, the rod 83
The switching valve 81 is swung via the lever 84, etc.
It is possible to switch between a state in which the communication passage 18 is blocked and a state in which the communication passage 18 is opened and the interior of the cooler duct 60 is communicated with the downstream portion of the intake duct 10.

In the latter state, the portion of the intake duct 10 upstream of the intake port 14 or opening 17 is shut off from the downstream portion by the switching valve 81.

Then, the switching valve 8 is connected via the actuator 82.
1, and the controller 80 receives a signal from a vehicle speed sensor 85 that detects the vehicle speed of the vehicle, a signal from an engine rotation sensor 86 that detects the rotation speed of the engine 1, and a throttle control. A signal from a throttle opening sensor 87 that detects the opening of the valve 2 is input.

In this embodiment, as shown in FIGS. 1 and 6, a receiver tank case housing a receiver tank 91 storing refrigerant for an air conditioner is installed on the side of the cooler duct 60 in the left front part of the engine room 3. 92, and a battery case 93 housing a battery (not shown) is disposed behind the battery case 92, and a communication passage 94 that communicates the interior of the cooler duct 60 with the interior of the receiver tank case 92, and the receiver tank. A communication path 95 is provided that communicates the inside of the case 92 and the inside of the battery case 93.

Next, the operation of the above embodiment will be explained.

When the engine 1 is operating, the intake air taken into the duct 10 from the intake port 14 at the left end of the intake duct 10 is as follows:
Air is supplied from the intake outlet 15 at the right end of the duct 10 through the connecting pipe section 16.26 to the air cleaner 20, where dust and foreign matter are removed. This intake air is then supplied to the exhaust turbo supercharger 30 via the passage 51, and after being pressurized by the energy of the exhaust gas in the supercharger 30, it is further supplied to the intercooler 40 via the passage 52.
is introduced into the passage 53 and cooled by the cooler 40.
and is supplied to each combustion chamber of the engine 1 via the throttle valve 2.

On the other hand, when the vehicle is running, the running wind introduced into the radiator duct 71 from the air intake lower at the front of the vehicle body shown in FIG. cooling water. Further, since the air inlet 62 at the tip of the cooler duct 60 is opened in the radiator duct 71, a part of the running air introduced into the radiator duct 71 is branched into the cooler duct 60, and the intercooler 40 heat exchange section 46. As a result, the intake air, whose temperature has increased when pressurized by the exhaust turbo supercharger 30, is cooled by the running wind in the intercooler 4o, and is then supplied to the combustion chamber of the engine 1. .

Particularly in this intake system, the intake duct 10 is provided with a communication passage 18 that communicates with the inside of the cooler duct 60, and a switching valve 8 that opens and closes the communication passage 18 is provided.
1, and the valve 81 is controlled to open and close by the controller 80 via the actuator 82 according to the operating state of the engine 1. Next, the control of the switching valve 81 by the controller 80 is controlled by the controller 80 via the actuator 82. The explanation will be given according to the flowchart shown in the figure.

First, in step S1, the controller 80, based on the signals from each sensor 85, 86, 87 shown in FIG.
The vehicle speed, engine speed, and throttle opening of the vehicle are read, and then in step S2 it is determined whether the vehicle speed is smaller than a predetermined value (for example, 40 km/h). and,
If the predetermined value or more, then in step S3, it is determined from the rate of change of the throttle opening whether or not the engine 1 is in an acceleration state, and if it is not in an acceleration state, further step S3 is performed.
In step 4, it is determined whether the operating range of the engine 1 is in a high-load, high-speed range where the rotational speed and throttle opening are equal to or higher than predetermined values. If it is not in an acceleration state and is not in a high-load, high-speed region, in step S, the switching valve 81 is closed, that is, the communication passage 18 is cut off, and the connection between the intake duct 10 and the cooler duct 60 is cut off. Set it to the same state.

As a result, intake air is taken in from the intake inlet 14 at the tip of the intake duct 10 and supplied to the engine 1, as in the conventional case.

On the other hand, when the engine 1 is in an accelerating state or in the above-mentioned high-load high-speed region, that is, when high output is required, the controller 80 executes the above-mentioned step SS or steps S4 to S6. 1. The switching valve 81 is set to the open state. Therefore, in this case, by opening the communication passage 18 and communicating the cooler duct 60 with the downstream part of the intake duct 10, the running wind introduced from the radiator duct 71 into the cooler duct 60 is further introduced into the intake duct 10. , the intake duct 10
From there, it is supplied to the engine 1 through an air cleaner 20, an exhaust turbo supercharger 30, and an intercooler 40. In that case, the radiator duct 71 and the cooler duct 60 have a sufficiently large passage cross-sectional area and are installed so that the running wind is introduced while maintaining a large dynamic pressure, so that a large amount of intake air responds to the dynamic pressure. As a result, when a high output is required, an output corresponding to the request can be obtained. In addition, in this case, the intake air supplied to the engine 1 is low-temperature air taken in from outside the engine room 3, so the filling efficiency of the intake air is higher than when air from inside the engine room 3 is taken in. The output will also increase.

Furthermore, when this high output is required, the intake duct 10 and the cooler duct 60 are communicated with each other via the communication passage 18 as described above, so that the engine intake noise generated in the intake duct 10 is propagated into the cooler duct 60, and , and is discharged to the rear of the heat exchange section 46 together with the cooling air passing through the heat exchange section 46 of the intercooler 40.
This reaches the ears of the occupants in the vehicle interior behind the engine room 3. This sporty engine intake sound allows the occupants to experience a comfortable driving sensation during acceleration and the like.

Incidentally, when it is determined in step S2 in the flowchart of FIG. 7 that the vehicle speed is smaller than the predetermined value (40 km/h), the switching valve 81 is set to the closed state in step S. Therefore, even if the rate of change in the throttle opening is large and an acceleration state is determined in step S3, the intake duct 10 and the cooler duct may )
60 will not be communicated with. In other words, when the duct 60 and the intake duct 10 are communicated with each other on a low road where the running wind is not sufficiently introduced into the cooler duct 60, the heat exchange section 4 of the intercooler 40 is connected from the downstream side of the cooler duct 60.
6, the high-temperature air in the engine room 3 is taken in, leading to a decrease in intake air filling efficiency or output.
Furthermore, at low vehicle speeds, standing water on the road surface is likely to be sucked into the radiator duct 71 or the cooler duct 60, and there is a risk that this water may further flow into the engine 1 through the intake duct 10. Therefore, at low vehicle speeds or when the vehicle is stopped, the intake duct 10 and the cooler duct 60 are always shut off to prevent the above-mentioned problems.

Further, in this embodiment, a part of the running wind from inside the cooler duct 60 is introduced into the receiver tank case 92 through the passage 94, so that the air conditioner refrigerant in the receiver tank 91 housed in the case 92 is The refrigerant is cooled to prevent the refrigerant from deteriorating due to a rise in temperature.Furthermore, the running wind is also introduced into the battery case 93 from the receiver tank case 92 through the passage 95, thereby preventing a rise in the temperature of the battery. This will be prevented.

Here, the results of an experiment conducted by the present inventor regarding the above-mentioned embodiment regarding engine intake noise that provides a comfortable driving feeling to the occupants will be explained.

FIG. 8 shows the sound pressure level of the second-order component and the fourth-order component of the engine speed under the immediate force of the intercooler 40 when the intake duct 10 and the cooler duct 60 are communicated, and it shows the sound pressure level of the second-order component and the fourth-order component of the engine speed. While the second-order component, which produces sound, remains approximately constant as the engine speed increases, the fourth-order component, which provides a comfortable driving feeling for the occupants, is shown by arrow A.
As shown in the figure, the sound pressure level increases as the engine speed increases in the high speed range, and it was confirmed that this example provides a comfortable engine intake sound.

Note that FIG. 9 shows an example of the configuration of an intake device related to the present invention, in which, in addition to a cooler duct 102 that supplies running air to an intercooler 101, an auxiliary duct 103 through which running air passes in the front and rear direction is provided. At the same time, a communication section 105 is provided between the auxiliary duct 103 and the intake duct 104.
The communication portion 105 is provided with a switching valve 106 that opens during acceleration or the like.

According to this example, during acceleration, engine intake noise generated in the intake duct 104 is transmitted from the communication portion 105 to the auxiliary duct 1.
03 and is emitted rearward from the opening at the rear end of the duct 103, giving the occupant a comfortable driving feeling as in the above embodiment.

In this example, an intercooler was used as the cooling device, but if an oil cooler and an oil cooler duct for introducing running air into the cooler are installed in the engine room, this duct may also be used. A similar effect can be obtained.

(Effects of the Invention) As described above, according to the engine intake system according to the present invention, when high output is required such as during acceleration, by using the cooling duct into which running air for intercooler etc. is introduced, it is possible to Without installing a duct, a sufficient amount of low-temperature intake air taken in from outside the engine room can be supplied to the engine with good responsiveness, resulting in output that meets demand. In addition, during acceleration, the engine intake noise generated in the intake duct is emitted toward the passenger compartment through the cooling duct, and this reaches the ears of the passengers as a sporty sound, creating a comfortable sound for the passengers. This will give you the feeling of driving.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view showing the arrangement of each component of the intake system in the engine room, and FIG. 2 is a longitudinal cross-sectional side view of the same taken along the line ■-■ in FIG. Figure 3, Figure 4, and Figure 6 are the same as Figure 1 m-■ line,
5 is a rear view of the intake duct as seen from arrow V in FIG. 4; FIG. 7 is a flowchart showing the opening/closing control of the switching valve; FIG. 8 is a graph showing experimental results regarding engine intake noise, and FIG. 9 is a schematic plan view showing a configuration example of an intake device related to the present invention. 1...Engine, 3...Engine room, 10...
- Intake duct, 18... Communication path, 40... Cooling device (intercooler), 60... Cooling duct (cooler duct), 81... Valve means (switching valve). Applicant: Mazda Co., Ltd.

Claims (1)

[Claims] (1) An intake system for an engine in a vehicle that is equipped with an intake duct in the engine room that supplies intake air to the engine, and a cooling duct that guides running air as cooling air to a cooling device installed in the engine room. A communication passage is provided that communicates the cooling duct with the downstream side of the inflow opening end of the intake duct, and the communication passage is provided with a communication passage that connects the cooling duct to the intake duct in a specific operating state where high engine output is required. An intake device for an engine, characterized in that it is provided with valve means for communication.