JPH0921316A - Cooling device for vertical type engine for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form projected parts in heat insulating members covering the outer wall surfaces of exhaust pipes, letting a part of vehicle running air ventilating within gaps between each exhaust pipe and each heat insulating member be introduced into gaps between the adjacent exhaust pipes, and let vehicle running air be brought into contact with the whole circumferences of all of the exhaust pipes so as to eliminate the scattering of a cooling action. SOLUTION: When a vehicle starts running, after vehicle running air A has flown in the inside of an engine room, a part of vehicle running air flows in the spaces of exhaust pipes 19 from an air inlet 20. Vehicle running air A passes trough respective gaps 11in and 11out formed between each branch part 51 through 54 of an exhaust manifold and each of an inner and an external heat insulating members 10in and 10out in order, after it has cooled the exhaust manifold, it is exhausted out of an air outlet 21. In this case, the parts A1 through A3 of vehicle running air is introduced into gaps 14a and 14c at the respective branch parts by forming respective projected parts 12a, 12c and 13b in the inner and external heat insulating members 10in and 10out. By this constitution, even, if the respective branch parts 51 through 54 are mutually piled up as viewed forward from the rear, the branch parts located at the rear of the vehicle can thereby be sufficiently cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling system for a vertical engine for a vehicle.

[0002]

2. Description of the Related Art An engine body is arranged such that its longitudinal axis is substantially parallel to the moving direction of a vehicle, and a plurality of exhaust pipes are spaced apart from each other along the engine longitudinal axis. A cooling device for a vertically installed engine for a vehicle, which is connected to and cools these exhaust pipes by a vehicle traveling wind, wherein outer outer wall surfaces of these exhaust pipes are arranged with a gap from the exhaust pipes. It is covered with an outer heat insulating member, the inner outer wall surface of the exhaust pipe is covered with an inner heat insulating member spaced from the exhaust pipe, and the outer heat insulating member and the inner heat insulating member There is known a cooling device that cools these exhaust pipes by guiding a vehicle running wind into a defined space (actually, Kaihei 2-78).
718). In this cooling device, the exhaust pipe is cooled by the vehicle running wind so that the exhaust pipe is not overheated by the heat of the exhaust gas flowing through the internal space of the exhaust pipe, and the thermal strain of the exhaust pipe is minimized. On the other hand, the outer heat insulating member and the inner heat insulating member block the heat radiation from the exhaust pipe to prevent other parts in the engine room from overheating, or the catalytic converter is heated quickly when the engine is started. I have to.

[0003]

By the way, in a normal engine, the heights of the exhaust pipes from the bottom surface of the cylinder head are substantially constant. Therefore, when viewed from the front of the vehicle, the exhaust pipes overlap each other. It looks like this, and this overlap is extremely large. However, in such an engine, when the exhaust pipes are cooled by the vehicle traveling wind as in the cooling device described above, the vehicle traveling wind is not sufficiently hit as much as the exhaust pipe located at the rear of the vehicle,
That is, there is a problem that the exhaust pipe located at the rear of the vehicle is not cooled sufficiently, and thus the cooling action on the exhaust pipe varies widely.

[0004]

According to the first aspect of the present invention, the engine body is arranged such that its longitudinal axis is substantially parallel to the moving direction of the vehicle. A plurality of exhaust pipes are connected to the main body along the longitudinal axis of the engine so as to be separated from each other, and these exhaust pipes are cooled by the vehicle traveling wind. The outer wall surface of the pipe is covered with a heat insulating member that is arranged with a gap from the exhaust pipe, and the heat insulating member is provided with a convex portion that projects toward the exhaust pipe. At least a part of the vehicle running wind flowing in the gap is guided into the gap formed between the exhaust pipes adjacent to each other.

According to the second aspect of the invention, in order to solve the above-mentioned problems, the engine body is arranged so that its longitudinal axis is substantially parallel to the moving direction of the vehicle. In a cooling device for a vertical engine for a vehicle, in which a plurality of exhaust pipes are connected to be spaced apart from each other along an axis, and the exhaust pipes are cooled by vehicle wind, the outer wall surfaces of these exhaust pipes are exhausted. It is covered by a heat insulating member arranged with a gap from the pipe, and the gap formed between the heat insulating member and each exhaust pipe is made different from each other in the adjacent exhaust pipes and flows through the gap between the exhaust pipe and the heat insulating member. At least a part of the traveling wind of the vehicle is guided into the gap formed between the exhaust pipes adjacent to each other.

According to the third aspect of the invention, in order to solve the above problems, the engine body is arranged so that its longitudinal axis is substantially parallel to the moving direction of the vehicle. In a cooling device for a vertical engine for a vehicle, in which a plurality of exhaust pipes are connected to be spaced apart from each other along an axis, and the exhaust pipes are cooled by vehicle wind, the outer wall surfaces of these exhaust pipes are exhausted. A vehicle that is covered with a heat insulating member that is arranged with a gap from the pipe, and that has a protruding portion that projects toward the heat insulating member on the exhaust pipe, and that the protruding portion allows the vehicle to flow in the gap between the exhaust pipe and the heat insulating member. At least a part of the traveling wind is guided into a gap formed between the exhaust pipes adjacent to each other.

[0007]

Since at least a part of the vehicle running wind flowing in the gap between the exhaust pipe and the heat insulating member is guided into the gap formed between the exhaust pipes adjacent to each other, all the exhaust pipes travel over almost the entire circumference. To be cooled.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, an engine body 3 is vertically arranged in an engine room 2 of a vehicle 1. That is, the engine body 3 is arranged so that the longitudinal axis K-K of the engine body 3 is substantially parallel to the moving direction of the vehicle 1, to be precise, the straight traveling direction. Further, as shown in FIG. 1, the engine body 3 is provided with, for example, four cylinders along the longitudinal axis KK. In the following, these cylinders will be referred to as the first cylinder # in order from the cylinder located on the front side of the vehicle 1.
The first and second cylinders # 2, the third cylinder # 3, and the fourth cylinder # 4 will be referred to. Each of the cylinders # 1 to # 4 is common to each cylinder arranged on one side of the longitudinal axis KK through the corresponding intake port formed in the cylinder head of the engine body 3 and the intake branch pipe. Connected to the surge tank 4. The surge tank 4 is connected to an air flow meter (not shown) via an intake duct (not shown).

Further, each of the cylinders # 1 to # 4 is arranged on the other side of the longitudinal axis K-K via a corresponding exhaust port formed in the cylinder head 10, and the exhaust manifold 5 common to each cylinder is provided. Connected to. The exhaust manifold 5 has a longitudinal axis K-K of the engine body 3 as shown in FIG.
Four branch parts 51, 5 that are provided apart from each other along the
2, 53, 54, and the first branch portion 51
The second branch portion 52 is connected to the second cylinder # 2, the third branch portion 53 is connected to the third cylinder # 3, and the fourth branch portion 54 is connected to the fourth cylinder # 4. ing. These branch parts 51, 52, 53, 54 constitute an exhaust pipe. Further, in the present embodiment, the central axes of the branch parts 51, 52, 53, 54 are aligned on the straight line L-L as shown in FIG. This straight line L-L extends substantially parallel to the longitudinal axis K-K of the engine body 3. The collecting portion 50 of the exhaust manifold 5 is connected to a catalytic converter (not shown).

Referring again to FIG. 1, an engine-driven cooling fan 7 is attached to the end surface of the engine body 3 located on the front side of the vehicle 1. A radiator 8 is arranged in front of the cooling fan 7 in the vehicle, and a front grill 9 which communicates between the engine room 2 and the atmosphere is provided in front of the radiator 8 in the vehicle. Therefore, as the vehicle 1 travels, the vehicle traveling wind A that advances in the longitudinal axis KK direction of the engine body 3 flows into the engine room 2 through the front grill 9.

As can be seen in particular from FIGS. 2 and 3, the inner and outer wall surfaces 5 in of the exhaust manifold 5, that is, the outer wall surface on the engine body 3 side, has a gap of 11 in from the exhaust manifold 5.
Is covered by an inner heat insulating member 10in arranged apart from each other, and the outer outer wall surface 5out of the exhaust manifold 5 is covered by an outer heat insulating member 10out arranged apart from the exhaust manifold 5 by a gap 11out. . Therefore, the inner heat insulating member 10i in which the inner and outer wall surfaces of the respective branch parts are common
Thus, the outer outer wall surface of each branch portion is covered with the common outer heat insulating member 10out. In other words, the exhaust manifold 5 is arranged in the space 19 defined by the inner heat insulating member 10in and the outer heat insulating member 10out, and the vehicle traveling wind A is introduced into the space 19 as described later. Will be done. Therefore, the gap 20 between the end of the inner heat insulating member 10in located on the side of the first branch 51 and the end of the outer heat insulating member 10out forms an air intake port, and is located on the side of the fourth branch 54. The end of the inner heat insulating member 10 in and the outer heat insulating member 1
The gap 21 between the ends of 0out forms an air outlet. On the other hand, the inner heat insulating member 10in and the outer heat insulating member 10out block heat radiation from the exhaust manifold 5 to prevent other parts in the engine room 2 from being overheated, or the catalytic converter operates quickly when the engine is started. It is heated to. Also, particularly the inner heat insulating member 10i
n also prevents the exhaust manifold 5 from receiving heat from the engine body 3. The inner heat insulating member 10in and the outer heat insulating member 10out are supported by, for example, the exhaust manifold 5 by a supporting member (not shown).

Still referring to FIG. 3, the outer heat insulating member 1
Projections 12a and 12c projecting toward the exhaust manifold 5 are provided on the side wall surface of the exhaust manifold 5 of 0out,
On the side wall surface of the exhaust manifold 5 of the inner heat insulating member 10in, a convex portion 13b protruding toward the exhaust manifold 5 is also provided. The convex portion 12a includes the first branch portion 51 and the second branch portion 5
The convex portion 13b is positioned on the first inter-branch portion gap 14a formed between the two, and the convex portion 13b is formed between the second branch portion 52 and the third branch portion 53. The convex portion 12c is positioned above, and the convex portion 12c is positioned above the third inter-branch portion gap 14c formed between the third branch portion 53 and the fourth branch portion 54. Therefore, the inner heat insulating member 10i
The convex portions formed in n and the convex portions formed in the outer heat insulating member 10out are alternately arranged in the longitudinal axis K-K direction of the engine body 3. The inner heat insulating member 10in and the outer heat insulating member 10out have a substantially flat plate shape except for the convex portion, and in the present embodiment, the inner heat insulating member 10in and the outer heat insulating member 10out have a straight line L-L. Each extends in parallel.

Next, the operation of the cooling device according to this embodiment will be described with reference to FIG. When the vehicle traveling wind A flows into the engine room 2 due to the traveling of the vehicle 1, a part of the vehicle traveling wind A flows into the exhaust pipe space 19 from the air intake port 20. The vehicle running wind A that has flowed into the exhaust pipe space 19 then has a gap 11ou formed between each branch and the outer heat insulating member 10out as shown by an arrow in FIG.
t and the gap 11in formed between each branch portion and the inner heat insulating member 10in, are sequentially circulated to contact the exhaust manifold 5, thereby cooling the exhaust manifold 5. As a result, the exhaust manifold 5 is prevented from overheating. The traveling wind that has circulated in the exhaust pipe space 19 is then discharged to the air outlet 2
Emitted from 1.

However, as can be seen from FIG. 2, when viewed from the front of the vehicle 1, the respective branch portions of the exhaust manifold 5 appear to overlap each other, and the overlap is so large that they are located behind the vehicle 1. The vehicle traveling wind is not sufficiently exposed to the branch portion, that is, the branch portion located rearward of the vehicle is not sufficiently cooled. In other words, there will be a large variation in the cooling action for each branch. In particular, when the branch portion is a part of the exhaust manifold 5 as in the present embodiment and a great variation occurs in the cooling action for each branch portion, a large thermal strain occurs in the exhaust manifold 5 and durability of the exhaust manifold 5 and The reliability is reduced. Therefore, in this embodiment, the inner heat insulating member 1 is used.
A convex portion is provided on 0 in and the outer heat insulating member 10out, and the convex portion guides a part of the vehicle traveling wind A into the inter-branch gaps 14a, 14b, 14c.

That is, the vehicle traveling wind A flowing into the exhaust pipe space 19 from the air intake port 20 then flows through the gap 11out and the gap 11in around the first branch portion 51. As a result, the first branch portion 51 comes into contact with these traveling winds and is cooled. Gap 11 around the first branch 51
The traveling wind that has circulated inside out then travels along the convex portion 12a and is guided, so that part A1 of this traveling wind is the first portion.
Across the inter-branch gap 14a of the second branch 5
2 flows into the gap 11out. The traveling wind A1 that crosses the first inter-branch gap 14a contacts the back wall surface of the first branch portion 51, that is, the downstream side wall surface of the traveling wind, and cools this back wall surface. Therefore, the first branch portion 51 comes into contact with the traveling wind over substantially the entire circumference, and thus the first branch portion 51 is cooled more favorably. further,
The traveling wind A1 also contacts the front wall surface of the second branch portion 52, that is, the upstream side wall surface of the traveling wind to cool the front wall surface, so that the second branch portion 52 is also cooled more favorably.

The traveling wind flowing around the first branch portion 51 then flows through the gap 11out and the gap 11in around the second branch portion 52. As a result, the second branch portion 52
Are cooled by contacting these traveling winds. The traveling wind that has circulated in the gap 11in around the second branch portion 52 then travels along the convex portion 13b and is guided, and thus a part A2 of this traveling wind crosses the second gap portion 14b between the branch portions. Then, the rest flows into the gap 11in around the third branch portion 53.
The traveling wind A2 that crosses the second inter-branch gap 14b is the second
The back wall surface of the branch portion 52 is contacted to cool this back wall surface. Therefore, the second branch portion 52 also comes into contact with the traveling wind over substantially the entire circumference, and thus the second branch portion 52 is cooled more favorably. Further, the traveling wind A2 also contacts the front wall surface of the third branch portion 53 and cools this front wall surface, so that the third branch portion 53 is also cooled even better.

The traveling wind flowing around the second branch portion 52 then flows through the gap 11out and the gap 11in around the third branch portion 53. As a result, the third branch portion 53
Are cooled by contacting these traveling winds. The traveling wind that has circulated in the gap 11out around the third branch portion 53 then travels along the convex portion 12c and is guided, so that part A3 of this traveling wind crosses the third inter-branch portion gap 14c. Then, the rest flows into the gap 11out around the fourth branch portion 54. The traveling wind A3 crossing the third inter-branch gap 14c contacts the back wall surface of the third branch portion 53 to cool the back wall surface. Therefore, the third branch portion 53 also comes into contact with the traveling wind over almost the entire circumference, and thus the third branch portion 53 is cooled more favorably. Furthermore, traveling wind A3
Also contacts and cools the front wall of the fourth branch 54, so that the fourth branch 54 is also cooled better.

The traveling wind flowing around the third branch portion 53 then flows through the gap 11out and the gap 11in around the fourth branch portion 54. As a result, the fourth branch 54
Are cooled by contacting these traveling winds. The traveling wind is then discharged from the air discharge port 21. In this case, the end of the outer heat insulating member 10out on the side of the air discharge port is the exhaust manifold 5.
The traveling wind flowing in the gap 11out around the fourth branch portion 54 comes into contact with the back wall surface of the fourth branch portion 54. As a result, the fourth branch portion 54 also comes into contact with the traveling wind over almost the entire circumference, and thus the fourth branch portion 54 is cooled more favorably.

As described above, in this embodiment, the inter-branch gap 1
Since the running wind is guided into the interiors of the vehicles 4a, 14b, 14c, the branch located behind the vehicle 1 can be satisfactorily cooled even when the branches overlap each other when viewed from the front. It is possible to reduce variations in the cooling action for each branch. As a result, it is possible to prevent the heat load acting on the exhaust manifold 5 from varying, so that it is possible to prevent a large thermal strain from occurring in the exhaust manifold 5, and thus the durability of the exhaust manifold 5 and The reliability can be improved.
Further, in the present embodiment, the inter-branch gaps 14a, 14b, 14
The convex portion for guiding the traveling wind into the c is provided with the outer heat insulating member 10 ou.
t and the inner heat insulating member 10in are integrally provided. Therefore, good cooling of the exhaust manifold 5 can be ensured without increasing the number of parts. Further, the outer heat insulating member 10out and the inner heat insulating member 10i
The convex portion can be easily formed by curving n to form the convex portion.

FIG. 4 shows another embodiment. The cooling device of the present embodiment is also applied to the vertical engine as shown in FIG. Referring to FIG. 4, in this embodiment, the inner heat insulating member 10in as in the embodiment of FIG. 3 is omitted, so that the exhaust pipe space 19 has the outer heat insulating member 10ou.
It is defined by t and the outer wall surface of the engine body 3. In addition, each branch portion of the exhaust manifold 5 is arranged with a gap 22 in from the outer wall surface of the engine body 3. Moreover, as shown in FIG.
At t, a convex portion 12a protruding toward the exhaust manifold 5,
12b and 12c are formed. The convex portion 12a is on the first inter-branch portion gap 14a, and the convex portion 12b is on the first inter-branch portion gap 14b.
The convex portions 12c are arranged above the inter-branch gaps 14c.

Also in the example shown in FIG. 4, the first branch portion 5
The traveling wind that has circulated in the gap 11out around the 1 then travels along the convex portion 12a, and as a result, a part A1 of this traveling wind is generated.
Crosses the first inter-branch gap 14a, and the rest flows into the gap 11out around the second branch 52. Further, the traveling wind that has circulated in the gap 11out around the second branch portion 52 then travels along the convex portion 12b, and as a result, a part A2 of this traveling wind crosses the second inter-branch portion gap 14b, The rest flows into the gap 11out around the third branch portion 53. Similarly, the traveling wind that has circulated in the gap 11out around the third branch portion 53 then travels along the convex portion 12c, and as a result, a part A3 of this traveling wind is generated in the gap 14 between the third branch portions.
c, and the rest is the gap 11o around the fourth branch 54.
flows into ut. For this reason, it is possible to cool each of the branch portions over substantially the entire circumference, and thus it is possible to reduce variations in the cooling action for each of the branch portions. As a result, it is possible to prevent a large thermal strain from occurring in the exhaust manifold 5, so that the durability and reliability of the exhaust manifold 5 can be improved. Note that the other configurations and operations of the cooling device are similar to those of the embodiment shown in FIGS.

FIG. 5 shows still another embodiment. Referring to FIG. 5, the outer heat insulating member 10out is provided with protrusions 12a, 12b, 12c similar to those of the embodiment shown in FIG.
However, in the example shown in FIG.
out is a straight line M− inclined by an angle θ1 with respect to the straight line L−L.
It is placed on M. As a result, the gap 11out formed between each branch portion and the outer heat insulating member 10out is made smaller toward the downstream side of the traveling wind.

Also in this embodiment, a part A1 of the traveling wind that has circulated through the gap 11out around the first branch portion 51 is the convex portion 12a.
Is guided by and crosses the first inter-branch gap 14a,
A part A2 of the traveling wind flowing through the gap 11out around the second branch portion 52 is guided by the convex portion 12b and crosses the second inter-branch portion gap 14b, and the gap 11out around the third branch portion 53 is formed. A part A3 of the circulating running wind is guided by the convex portion 12c and crosses the third inter-branch gap 14c.
As a result, each of the branch portions comes into contact with the running wind and is cooled over almost the entire circumference.

By the way, in the embodiment described with reference to FIG. 4, the size of the gap 11out formed between each branch portion and the outer heat insulating member 10out is substantially constant with respect to the flow direction of traveling wind. However, the protrusions 12a, 12b,
When part of the traveling wind A1, A2, A3 is guided into the inter-branch gaps 14a, 14b, 14c by 12c, the gap 11
The running wind that circulates in out gradually decreases. As a result, the wall surface on the outer heat insulating member 10out side is not sufficiently cooled in the branch portion located on the downstream side of the traveling wind. Therefore, in the embodiment shown in FIG. 5, the gap 11out formed between each branch portion and the outer heat insulating member 10out is reduced toward the downstream side of the traveling wind, whereby the flow velocity of the traveling wind is increased toward the downstream side of the traveling wind. I am trying to become. As the flow velocity of the traveling wind increases, the cooling performance due to it increases. Therefore, the branch portion located on the downstream side of the traveling wind can be cooled well, so that the branch portion of the exhaust manifold 5 can be cooled substantially uniformly. Thus, the durability and reliability of the exhaust manifold 5 can be further improved. The other structure and operation of the cooling device are similar to those of the embodiment shown in FIG.

FIG. 6 shows still another embodiment. Referring to FIG. 6, in this embodiment, an inner heat insulating member 10in and an outer heat insulating member 10out are provided as in the example of FIG.
The exhaust manifold 5 is arranged in the exhaust pipe space 19 defined by these heat insulating members. However, the inner heat insulating member 10 in and the outer heat insulating member 1 in this embodiment are
Each 0out has a flat plate shape. Further, the central axis of each branch portion is aligned on a straight line L-L, which is inclined by an angle θ2 with respect to a straight line N-N parallel to the longitudinal axis K-K of the engine body 3. Is provided.
As a result, the overlap of the branch portions in the front view is smaller than that in the example shown in FIG. 3, for example.

As shown in FIG. 6, the first branch portion 51.
The traveling wind A flowing through the surrounding gap 11in then collides with the outer wall surface of the second branch portion 52, and as a result, a part A1 of this traveling wind crosses the inside of the inter-branch gap 14a and the rest is the second. It flows into the gap 11 in around the branch portion 52. The traveling wind that has circulated through the gap 11in around the second branch portion 52 then collides with the outer wall surface of the third branch portion 53, and as a result, a part A2 of this traveling wind crosses the inside of the gap 14b between the branch portions, The rest flows into the gap 11in around the third branch portion 53. The traveling wind that has circulated through the gap 11in around the third branch portion 53 then collides with the outer wall surface of the fourth branch portion 54, and as a result, a part A3 of this traveling wind crosses the inside of the gap 14c between the branch portions,
The rest flows into the gap 11in around the fourth branch 54. As a result, each of the branch portions comes into contact with the running wind and is cooled over almost the entire circumference. Further, in the present embodiment, similarly to the example shown in FIG. 5, the gap 11in between each branch portion and the inner heat insulating member 10in is made smaller toward the downstream side of the traveling wind, and as a result, the flow velocity of the traveling wind becomes smaller. Since the height increases as it goes downstream, the branch portion of the exhaust manifold 5 can be cooled substantially uniformly. Therefore,
The durability and reliability of the exhaust manifold 5 can be further improved. Other configurations and operations of the cooling device are similar to those of the embodiment shown in FIG.

FIG. 7 shows still another embodiment. Referring to FIG. 7, in the present embodiment, a flat plate-like inner heat insulating member 10in and outer heat insulating member 10ou similar to the example shown in FIG.
t is provided. However, in the present embodiment, the central axis lines of the first and third branch portions 51, 53 of the exhaust manifold 5 are arranged on the straight line L1-L1, and the central axis lines of the second and fourth branch portions 52, 54 are respectively arranged. The central axis is the straight line L1-
It is arranged on a straight line L2-L2 different from L1. Therefore, the central axis of the first branch part 51 and the central axis of the second branch part 52 are arranged so as to be offset from each other, and the central axis of the second branch part 52 and the central axis of the third branch part 53 are The central axis of the third branch portion 53 and the central axis of the fourth branch portion 54 are displaced from each other. As a result, the gap 11out around the first branch portion 51 and the gap 11ou around the second branch portion 52.
Since t is different from each other, the gap 11out around the second branch portion 52 and the gap 11out around the third branch portion 53 are different from each other, and the gap around the third branch portion 53 is The gap 11out and the gap 11out around the fourth branch portion 54 are made different from each other. In addition, the gap 1 around the first branch portion 51
1 in and the gap 11 in around the second branch part 52 are made different from each other, and the gap 11 in around the second branch part 52 and the gap 11 in around the third branch part 53.
And the gap 11in around the third branch portion 53 and the gap 11in around the fourth branch portion 54 are different from each other. The straight lines L1-L1 and L2-L2 are parallel to the longitudinal axis K-K of the engine body 3.

As shown in FIG. 7, the first branch portion 51
The traveling wind A flowing through the surrounding gap 11in then collides with the outer wall surface of the second branch portion 52, and as a result, a part A1 of this traveling wind crosses the inside of the inter-branch gap 14a and the rest is the second. It flows into the gap 11 in around the branch portion 52. The traveling wind that has flowed through the gap 11out around the second branch portion 52 then collides with the outer wall surface of the third branch portion 53, and as a result, a part A2 of this traveling wind crosses the inside of the gap 14b between the branch portions, The rest flows into the gap 11out around the third branch portion 53. The traveling wind that has circulated through the gap 11in around the third branch portion 53 then collides with the outer wall surface of the fourth branch portion 54, and as a result, a part A3 of this traveling wind crosses the inside of the gap 14c between the branch portions, The rest flows into the gap 11in around the fourth branch 54. As a result, the respective branch portions come into contact with the running wind and are cooled over substantially the entire circumference, and thus the durability and reliability of the exhaust manifold 5 can be further improved. The other structure and operation of the cooling device are similar to those of the embodiment shown in FIG.

FIG. 8 shows still another embodiment. Each branch of the exhaust manifold 5 in the embodiments described thus far has a circular cross section. However, on the side wall surface of the outer heat insulating member 10out of each branch portion in the present embodiment, there is provided a projecting portion 5a that projects toward the outer heat insulating member 10out and toward the upstream side of traveling wind. Further, a projecting portion projecting toward the engine body 3 is also provided on the side wall surface of the engine body 3 of each branch portion, and therefore each branch portion has a diamond-shaped cross section.

As shown in FIG. 8, the first branch 51
The traveling wind A that has circulated through the surrounding gap 11out is the second
Colliding with the projecting portion 5a of the branch portion 52, part of the traveling wind A1 crosses the inter-branch gap 14a, and the rest flows into the gap 11out around the second branch portion 52.
The traveling wind that has circulated through the gap 11out around the second branch portion 52 then collides with the protruding portion 5a of the third branch portion 53, and as a result, a portion A2 of this traveling wind traverses within the inter-branch portion gap 14b. , The rest is the gap 11out around the third branch portion 53
Flows into. Gap 11out around the third branch portion 53
The traveling wind flowing through
As a result, a part A3 of the traveling wind traverses the inter-branch gap 14c, and the rest flows into the gap 11out between the fourth branch 54 and the outer heat insulating member 10out.
As a result, the respective branch portions come into contact with the running wind and are cooled over substantially the entire circumference, and thus the durability and reliability of the exhaust manifold 5 can be further improved.

In the example shown in FIG. 8, the projecting portion 5a is formed integrally with the branch portion by making the cross-sectional shape of the branch portion into, for example, a rhombus shape, but it is formed separately at the branch portion having a circular cross section. You may make it attach a protrusion part. However, by providing the projecting portion integrally with the branch portion as in the example of FIG. 8, the number of parts can be reduced and the manufacturing process can be simplified. Further, in the example shown in FIG. 8, the projecting portions 5a are provided at all the branch portions. However, the first branch portion 5 located on the most upstream side of the traveling wind A
1 does not need to be provided with a protrusion 5a, so
The branch portion 51 may have a circular cross section. The other structure and operation of the cooling device are similar to those of the embodiment shown in FIG.

In the embodiment shown in FIGS. 4, 5 and 8, the inner heat insulating member 10 in is omitted. However, for example, a flat plate-shaped inner heat insulating member 10 in may be provided.

[0033]

EFFECTS OF THE INVENTION Since all the exhaust pipes can be cooled by contacting them with the running wind over substantially the entire circumference, it is possible to reduce variations in the cooling action for the exhaust pipes.

[Brief description of drawings]

FIG. 1 is a top view of a vertically mounted engine.

FIG. 2 is a front view of a vertically mounted engine.

3 is a cross-sectional view of the exhaust manifold and heat insulating member taken along line III-III of FIG.

FIG. 4 is a sectional view of an exhaust manifold and a heat insulating member similar to FIG. 3 showing another embodiment.

FIG. 5 is a cross-sectional view of an exhaust manifold and a heat insulating member similar to FIG. 3 showing still another embodiment.

FIG. 6 is a cross-sectional view of an exhaust manifold and a heat insulating member similar to FIG. 3 showing still another embodiment.

FIG. 7 is a sectional view of an exhaust manifold and a heat insulating member similar to FIG. 3 showing still another embodiment.

FIG. 8 is a cross-sectional view of an exhaust manifold and a heat insulating member similar to FIG. 3 showing still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vehicle 3 ... Engine main body 5 ... Exhaust manifold 10in ... Inner heat insulating member 10out ... Outer heat insulating member 12a, 12b, 12c, 13b ... Convex part 14a, 14b, 14c ... Gap between branch parts 51, 52, 53, 54 ... Exhaust manifold branch A ... Vehicle running wind K ... Engine longitudinal axis

Claims (3)

[Claims] 1. An engine body is arranged such that its longitudinal axis is substantially parallel to the moving direction of a vehicle, and a plurality of exhaust pipes are spaced apart from each other along the engine longitudinal axis. In a vertical engine cooling device for a vehicle, which is connected to and cools the exhaust pipes by the vehicle traveling wind, the outer wall surfaces of the exhaust pipes are covered with a heat insulating member which is arranged with a gap from the exhaust pipes. The heat insulating member is provided with a convex portion that projects toward the exhaust pipe, and the convex portions allow at least some of the vehicle traveling air flowing in the gap between the exhaust pipe and the heat insulating member to be adjacent to each other. A cooling device designed to be guided into the gap formed between them. 2. The engine body is arranged such that its longitudinal axis is substantially parallel to the moving direction of the vehicle, and a plurality of exhaust pipes are spaced apart from each other along the engine longitudinal axis. In a vertical engine cooling device for a vehicle, which is connected to and cools the exhaust pipes by the vehicle traveling wind, the outer wall surfaces of the exhaust pipes are covered with a heat insulating member which is arranged with a gap from the exhaust pipes. The gaps formed between the heat insulating member and each exhaust pipe are made different from each other in the adjacent exhaust pipes so that at least a part of the vehicle traveling wind flowing in the gap between the exhaust pipe and the heat insulating member is adjacent to each other. A cooling device that is introduced into the space formed between the exhaust pipes. 3. The engine body is arranged so that its longitudinal axis is substantially parallel to the moving direction of the vehicle, and a plurality of exhaust pipes are spaced apart from each other along the engine longitudinal axis. In a vertical engine cooling device for a vehicle, which is connected to and cools the exhaust pipes by the vehicle traveling wind, the outer wall surfaces of the exhaust pipes are covered with a heat insulating member which is arranged with a gap from the exhaust pipes. The exhaust pipe is provided with a projecting portion projecting toward the heat insulating member, and the projecting portion causes at least some of vehicle running winds flowing in the gap between the exhaust pipe and the heat insulating member to be adjacent to each other. A cooling device designed to be guided into the gap formed between them.