JP2917588B2 - Exhaust system cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system cooling device that cools an exhaust system which is heated in an engine room of an automobile or the like by introducing outside air.

[0002]

2. Description of the Related Art Conventionally, cooling of an engine room of an automobile is disclosed in, for example, "Ventilation System for Engine Room" in Japanese Utility Model Laid-Open Publication No. Sho 59-182427. That is, in this conventional technique, an outside air introduction duct is provided on the back surface of the hood of an automobile, and the outside air introduced from the opening on the front grill side of the outside air introduction duct is blown to desired devices in an engine room to be cooled. ing.

[0003]

Therefore, according to the above-mentioned prior art, it is possible to specify and cool an exhaust system such as an exhaust manifold which is particularly high in temperature as desired equipment. It requires a considerable amount of outside air. However, when a large amount of outside air is introduced through the outside air introduction duct, there is a possibility that the aerodynamic characteristics of the vehicle may be deteriorated due to an increase in the amount of air blown, or conversely, the internal pressure of the engine room may be increased. When the internal pressure of the engine room increases, the amount of air passing from the front grill through the radiator decreases, and there is a problem that the cooling efficiency of the radiator deteriorates.

The present invention has been made in view of the above-mentioned circumstances, and has as its object to efficiently cool an exhaust system by introducing a relatively small amount of outside air without increasing the internal pressure of an engine room. An object of the present invention is to provide an exhaust system cooling device.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a method for controlling a vehicle locally in an engine room.
Exhaust for guiding outside air to an exhaust system that can be heated to cool it
A system cooling device, one end of which is opened to the outside from the engine hood, the air introduction passage and the other end is opened to the upper surface side of the local area of the exhaust system, provided on the lower surface side of the exhaust system, prior to
Serial outside air to be introduced into the upper surface side of the exhaust system through the outside air introduction passage, and a fresh air guide member for flow polarized to the lower side of the local of the exhaust system.

[0006]

SUMMARY OF] According to the above configuration, outside air is introduced into the upper surface of the exhaust system of the local through the outside air introduction passage, the outside air guide member, polarized flows to the lower side of the local of the exhaust system.
Therefore, the exhaust system can be operated at a particularly high
With emphasis on a local part which is apt to change, cooling is uniformly and effectively performed from the upper surface side and the lower surface side.

[0007]

【Example】

(First Embodiment) A first embodiment in which the exhaust system cooling device of the present invention is embodied in an automobile will be described in detail with reference to FIGS.

FIG. 1 is a schematic configuration diagram showing a side surface of an exhaust system cooling device provided in an engine room 1 of an automobile, and FIG. 2 is a schematic configuration diagram showing a plan view of the exhaust system cooling device. An engine 2 is provided in an engine room 1, and a front grill 3 is provided on the front side thereof. In addition, a radiator 4 is provided between the engine 2 and the front grill 3, and a traveling wind introduced through the front grill 3 when the vehicle travels is guided to the radiator 4 as a cooling wind.

An engine hood 5 is provided above the engine room 1, and a duct 6 forming an outside air introduction passage is integrally formed on one side of the engine hood 5. One end of the duct 6 is an outside air inlet 7 that opens to the outside, and traveling air is taken into the duct 6 as cooling air through the outside air inlet 7. The other end of the duct 6 is an outside air outlet 9 that opens on the upper surface side of the central portion of the exhaust manifold 8 that constitutes the exhaust system of the engine 2. The engine 2 of this embodiment has six cylinders, and the exhaust manifold 8 correspondingly has six branch passages 8a, 8b,
8c, 8d, 8e, and 8f. In this embodiment, the exhaust manifold 8 covers the entire upper surface side of the exhaust manifold 8.
An insulator 10 for heat insulation is provided to be supported by the engine 2. At the center position of the insulator 10, it rises upward and opens, and the outside air outlet 9.
There is provided a communication port 11 that communicates with. This communication port 1
Reference numeral 1 is arranged so as to be loosely fitted inside the outside air outlet 9, and a gap is provided between the two 11 and 9 to such an extent that interference can be avoided. In this embodiment, a bent guide piece 12 is provided at the inner bent portion of the duct 6 so as to guide only the flow of the cooling air introduced from the outside air inlet 7 to the communication port 11 of the insulator 10. I have. The upper end side of the guide piece 12 is fixed inside the duct 6,
The lower end is disposed corresponding to the communication port 11.

[0010] Cooling air introduced into the duct 6 is blown into the insulator 10 through the communication port 11, and is introduced into the space between the insulator 10 and the upper surface of the exhaust manifold 8. Here, the communication port 11 is arranged around the central portion where the temperature of the exhaust manifold 8 becomes the highest. The cooling air introduced into the duct 6 is intensively blown out around the central portion thereof, and flows along the inside of the insulator 10 over the entire upper surface side of the exhaust manifold 8.

On the other hand, on the lower surface side of the exhaust manifold 8, there is provided an impact plate 13 as an outside air guide member for causing the cooling air blown to the inside of the insulator 10 to drift toward the lower surface side of the exhaust manifold 8. As shown in FIG. 3, at positions facing the communication port 11 of the insulator 10, each of the branch passages 8 b, 8 c, around the central portion of the exhaust manifold 8 is located.
Branch spaces 8g and 8h between 8d are located. These branch spaces 8g and 8h constitute a guide passage for guiding a part of the cooling air blown out from the communication port 11 to the lower surface side of the exhaust manifold 8. In addition, branch space 8g, 8
The cooling air guided to the lower surface side of the exhaust manifold 8 through the hole h collides with the collision plate 13 and further flows between the collision plate 13 and the lower surface side of the exhaust manifold 8.

In addition, in this embodiment, a configuration for dealing with water droplets entering the duct 6 is added. That is, as shown in FIGS.
A draining slit 14 for separating water droplets entering along the duct 6 and the guide piece 12 is provided in the gap with the communication port 11. The slit 14 has its lower end bent outward. Also, the lower end side of the guide piece 12 is bent outward in accordance with the shape of the slit 14. Further, a gap between the outside air outlet 9 and the communication port 11 is a drain port 15. As shown by the dashed arrows in FIG. 4, water droplets separated from the duct 6 along the shapes of the guide pieces 12 and the slits 14 are guided to the upper surface side of the insulator 10 through the drain holes 15 thereof, and the exhaust manifold is formed. 8 is not exposed to water drops.

Next, the operation of the exhaust system cooling device configured as described above will be described. When the vehicle is running, running air is introduced as cooling air from the outside air inlet 7 into the duct 6, and the cooling air is efficiently guided from the duct 6 to the communication port 11 through the guide piece 12. Then, as indicated by the arrow in FIG. 5, the cooling air introduced through the communication port 11 is guided to the inside of the insulator 10 and is intensively blown out to the central portion on the upper surface side of the exhaust manifold 8, so that the portion is concentrated. It is blown and cooled. Part of the cooling air flows in the space between the inside of the insulator 10 and the upper surface of the exhaust manifold 8, and the other upper surface of the exhaust manifold 8 is blown and cooled.

In addition, a part of the cooling air blown toward the center of the upper surface side of the exhaust manifold 8 is supplied to the branch spaces 8g and 8g.
h to the lower surface of the exhaust manifold 8. Further, the guided cooling air collides with the collision plate 13 and is deflected, hits the lower surface side central portion of the exhaust manifold 8, and
This part is blast-cooled intensively. And the collision plate 13
A part of the cooling air that has collided with the air flows in the space between the collision plate 13 and the lower surface of the exhaust manifold 8, and the other lower surface of the exhaust manifold 8 is blown and cooled.

Therefore, the exhaust manifold 8 is positively blown and cooled not only from the upper surface side but also from the lower surface side, so that the exhaust manifold 8 can uniformly and effectively cool the upper and lower surfaces. Moreover, in this embodiment,
Cooling air introduced through the duct 6 or the like is first blown out to the center of the exhaust manifold 8, and the upper surface and the lower surface of the same portion are intensively cooled. Therefore, as the exhaust manifold 8, it is possible to locally and effectively cool the periphery of the central portion where the temperature becomes the highest.

Here, the temperature characteristics related to the cooling of the exhaust manifold 8 will be described. FIG. 6 is a graph illustrating a difference in temperature between the branch passages 8a to 8f in the exhaust manifold 8. The dashed line in FIG. 6 shows the temperature characteristics of the exhaust manifold 8 without the exhaust system cooling device as a comparative example. The exhaust manifold 8 of a multi-cylinder engine not equipped with a general cooling device has a convex-shaped temperature characteristic having the highest temperature around the center. Therefore, in a multi-cylinder engine not equipped with a cooling device, in order to cope with a high temperature in accordance with the highest temperature portion of the exhaust manifold 8, various adaptations such as a fuel increase correction of the engine and an ignition timing advance correction, etc. It is necessary to select the material.

On the other hand, the solid line in FIG. 6 shows the temperature characteristics of the exhaust manifold 8 provided with the exhaust system cooling device in this embodiment. As is clear from this graph,
The temperature characteristic in the present embodiment is such that the temperature is surely reduced around the central portion, which is the high temperature portion of the exhaust manifold 8,
It can be seen that there is a local cooling effect around the center.
Further, the temperature of each of the branch passages 8a to 8f of the exhaust manifold 8 is relatively lower than that of the comparative example, and it can be seen that there is an overall cooling effect of the exhaust manifold 8. Further, it can be seen that the temperature difference between the branch passages 8a to 8f is small, and that the exhaust manifold 8 achieves averaging of the temperature of each part.

As described above, according to the exhaust system cooling apparatus of this embodiment, a relatively small amount of outside air which can be taken in from the outside air intake 7 of the engine hood 5 is introduced.
The exhaust manifold 8 can be efficiently cooled.
Further, as described above, since it is possible to suppress the increase in the temperature of the highest temperature portion in the exhaust manifold 8 and to achieve the averaging of the temperature of each portion, the durability and reliability of the exhaust manifold 8 can be improved. .

Since the temperature of the exhaust manifold 8 can be suppressed, it is not necessary to perform an excessive fuel increase correction for the engine 2 as a measure against the temperature increase, and it is possible to improve the fuel efficiency and the exhaust emission. Further, the degree of freedom in selecting the material of the exhaust manifold 8 is expanded, and a low-grade material can be adopted, so that the cost of the exhaust manifold 8 can be reduced.

Further, in this embodiment, the engine hood 5
Since the duct 6 is formed and the insulator 10 is used as a heat shield for the exhaust manifold 8, it is not necessary to largely change the component arrangement and structure in the conventional engine room 1. Therefore, the exhaust manifold 8 can be cooled without compromising the degree of freedom in designing the component arrangement, component shape, component structure, and the like, while achieving compatibility with the heat damage of peripheral components.

In this embodiment, the cooling air introduced through the duct 6 is efficiently guided to the communication port 11 through the guide piece 12 and is blown out to the exhaust manifold 8 as the cooling air. Therefore, a desired cooling effect in the exhaust manifold 8 can be obtained with a minimum necessary amount of outside air. Therefore, the deterioration of the aerodynamic characteristics of the vehicle can be suppressed, the rise of the internal pressure of the engine room can be suppressed, the cooling efficiency of the radiator can be secured, and the exhaust manifold 8 can be cooled without deteriorating the performance of the vehicle. Can be.

In addition, in this embodiment, since the duct 6 of the engine hood 5 communicates with the outside, the hot air in the engine room 1 is led out through the duct 6 and the like before stopping or restarting. Will be done. Therefore, the duct 6 and the like can be made to function as a hot air vent, and it is also possible to provide a countermeasure against adverse effects at the time of restarting at a high temperature.

Further, since the draining slits 14 and the like are provided inside the duct 6 so that water droplets can be separated, the exhaust manifold 8 can be protected from raindrops entering during traveling.

(Second Embodiment) Next, FIGS. 7 and 8 show a second embodiment in which the exhaust system cooling device of the present invention is embodied in an automobile.
It will be described according to. Note that, in this embodiment, the first
The same members as those of the embodiment are denoted by the same reference numerals, and description thereof will be omitted. Only different points will be described.

FIG. 7 is a schematic configuration diagram showing a side surface of the exhaust system cooling device in the engine room 1. In this embodiment, an insulator 21 constituting an outside air guide member is different from the configuration of the first embodiment. I have. FIG. 8 shows a cross section for explaining the relationship between the insulator 21 and the exhaust manifold 8. That is, the insulator 21 has a shape that covers substantially the entire exhaust manifold 8, and guides the cooling air introduced from the communication port 11 of the insulator 21 by diverting to the upper surface side and the lower surface side of the exhaust manifold 8. The guide passage 22 has a double structure. A plurality of outlets 23 are formed in the guide passage 22 and open toward the upper surface and the lower surface of the exhaust manifold 8, and cooling air is blown toward the exhaust manifold 8 only from these outlets 23. Is done.

Although not shown in detail in FIGS. 7 and 8,
The position and the opening area of each outlet 23 are determined according to the exhaust manifold 8.
Are set in accordance with the temperature characteristics of. That is,
In this embodiment, the air outlets 23 are arranged corresponding to the respective branch passages 8a to 8f that require cooling in the exhaust manifold 8. Moreover, the opening area of each outlet 23 is set to be larger on the upper surface side and the lower surface side around the central portion where the temperature is highest in the exhaust manifold 8 so as to provide an air flow according to the temperature characteristic.

Therefore, the cooling air introduced into the duct 6 from the outside air inlet 7 is efficiently guided from the duct 6 to the communication port 11 through the guide piece 12. Then, as shown in FIG. 8, the cooling air introduced through the communication port 11 is guided to the upper surface side and the lower surface side of the exhaust manifold 8 through the guide passage 22 of the insulator 21. Further, the cooling air guided to the guide passage 22 is blown out from each outlet 23 to each part of the exhaust manifold 8 in a spot manner, and the part is blown and cooled. Moreover, on the upper surface side and the lower surface side of the exhaust manifold 8, more cooling air is blown from the outlet 23 having a large opening area around the central portion where the temperature is the highest.

Therefore, the exhaust manifold 8 is actively blown and cooled from the upper and lower sides thereof, and the exhaust manifold 8 is cooled.
As a result, it is possible to uniformly and effectively blow and cool the upper and lower surfaces. Moreover, in this embodiment, more cooling air is blown to the upper surface and the lower surface around the central portion of the exhaust manifold 8 where the temperature becomes the highest, so that the portion can be locally and effectively cooled. In addition, averaging of the temperature of each part can be achieved.

As a result, the exhaust manifold 8 can be efficiently cooled by introducing a relatively small amount of outside air that can be taken in from the outside air intake 7 of the engine hood 5. In addition, since it is possible to suppress an increase in the temperature of the highest temperature portion in the exhaust manifold 8 and to achieve averaging of the temperature of each portion, the durability and reliability of the exhaust manifold 8 can be improved.

Since the temperature of the exhaust manifold 8 can be suppressed from being raised, it is possible to omit an excessive fuel increase correction as a measure for raising the temperature, and to improve the fuel efficiency and the exhaust emission. Further, the degree of freedom in selecting the material of the exhaust manifold 8 is increased, and the cost can be reduced.

Further, also in this embodiment, it is not necessary to significantly change the arrangement and structure of the parts in the conventional engine room 1, and the compatibility with the heat damage of the peripheral parts is achieved, and the parts arrangement, parts shape and parts structure, etc. The exhaust manifold 8 can be cooled without impairing the degree of freedom in design in the above.

Also in this embodiment, a desired cooling effect in the exhaust manifold 8 can be obtained with a minimum necessary amount of outside air, so that the deterioration of the aerodynamic characteristics of the vehicle can be suppressed, and the engine room can be suppressed. The cooling efficiency of the radiator can be secured by suppressing an increase in the internal pressure.

In addition, also in this embodiment, the duct 6
And the like can function as hot air vents, and can also have countermeasures against adverse effects at the time of high temperature restart. Further, the exhaust manifold 8 can be protected from raindrops by the draining slits 14 and the like.

It should be noted that the present invention is not limited to the above-described embodiments, but may be carried out as follows by appropriately changing a part of the configuration without departing from the spirit of the invention. (1) In the first embodiment, an insulator 10 communicating with the outside air outlet 9 of the duct 6 is separately provided to guide the cooling air to the upper surface side of the exhaust manifold 8, but this insulator is omitted and the duct is omitted. The cooling air may be directly blown out from the outside air outlet to the exhaust manifold. Alternatively, the outer periphery of the outside air outlet may be formed in a shape like an insulator by omitting the insulator.

(2) In each of the above embodiments, the cooling air is guided to the central portion of the exhaust manifold 8 assuming the highest temperature around the central portion, but a portion other than the central portion of the exhaust manifold is most likely to be introduced. When the temperature becomes high, more wind may be guided to the site.

[0036]

As described above in detail, according to the present invention, the station of the exhaust system is controlled via the outside air introduction passage of the engine hood.
The structure adopted to introduce outside air to the upper side of the
Place the outside air introduction passage close to
The exit (other end) of the road can be located,
Can be intensively cooled by a relatively small amount of outside air.
It becomes possible. In addition, the outside air introduced to the upper surface side of the local portion of the exhaust system through the external air introduction passage of the engine hood is supplied to the local portion of the exhaust system by an external air guide member provided on the lower side of the exhaust system .
Of the exhaust system.
Ru can be efficiently cooled from upper and lower sides. Furthermore,
Compared with the present invention because it focuses on intensive cooling of the exhaust system
Cooling is possible even with a very small amount of outside air introduced.
The internal pressure of the engine room
Inconvenience that the introduction of outside air is hindered.
It has an excellent effect.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a side surface of an exhaust system cooling device provided in an automobile engine room according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a plane of an exhaust system cooling device in an engine room in a state where an engine hood is removed in the first embodiment.

FIG. 3 is an enlarged plan view illustrating a positional relationship among an exhaust manifold, an insulator, and a collision plate in the first embodiment.

FIG. 4 is a side sectional view illustrating, in an enlarged manner, a positional relationship among a duct, a guide piece, a draining slit, and an insulator in the first embodiment.

FIG. 5 is a longitudinal sectional view illustrating a relationship between an insulator and an exhaust manifold in the first embodiment.

FIG. 6 is a graph illustrating a difference in temperature of each part in the exhaust manifold in the first embodiment.

FIG. 7 is a schematic configuration diagram showing a side surface of an exhaust system cooling device provided in an automobile engine room according to a second embodiment of the present invention;

FIG. 8 is a longitudinal sectional view illustrating a relationship between an insulator and an exhaust manifold in a second embodiment.

[Explanation of symbols]

Reference numeral 5 denotes an engine hood, 6 denotes a duct constituting an outside air introduction passage, 7 denotes an outside air intake, 8 ... an exhaust manifold constituting an exhaust system, 9 ... an outside air outlet, 10 ... an insulator, 13 ...
Impact plate constituting an outside air guide member, 21... Insulator constituting an outside air guide member.

Claims (1)

(57) [Claims] 1. High temperature locally in an engine room
Exhaust system cooling to guide outside air to the exhaust system
A retirement unit, one end of which is opened to the outside from the engine hood, the air introduction passage and the other end is opened to the upper surface side of the local of the <br/> exhaust system provided on the lower surface side of the exhaust system, An exhaust system cooling device , comprising: an external air guide member for diverting external air introduced into the upper surface of the exhaust system through the external air introduction passage toward the lower surface of the local portion of the exhaust system.