JPS5827090Y2 - Engine intake air heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine intake air heating device that heats intake air upstream of an air cleaner using heat radiation from an exhaust manifold.

Conventionally, in order to improve engine warm-up characteristics and prevent carburetor icing, a hot air cover 2 has been installed around the exhaust manifold 1 of the engine, as shown in FIGS. 1 and 2.
The intake air is heated by flowing through the heating passage 3 formed between the hot air cover 2 and the exhaust manifold 1, and the heated intake air is passed through an air cleaner (not shown).

) is well known as an engine intake air heating device that increases the intake air temperature by introducing the air into the engine.

However, in the conventional type, the gap between the entire circumference of the lower edge 2a of the hot air cover 2 and the exhaust manifold 1 is used as the air inlet 4 to introduce air, so that the engine cooling air shown by arrow A is e.g. There is a drawback that the heated air in the heating passage 3 is agitated and diluted by the wind or the air blown from the cooling fan, resulting in a reduction in the thermal effect.

Furthermore, if the hot air cover 2 is formed to enclose the exhaust manifold 1 to block the influence of the engine cooling air, as shown by the imaginary lines in FIGS. Even at high loads and high rotations, the engine cooling air is blocked and the hot air cover 2 functions as a kind of insulation box, so the exhaust manifold 1 is not cooled and the exhaust gas flowing inside becomes hotter than necessary.
There is a problem that thermal deterioration of the exhaust manifold 1 and the exhaust gas purification device and exhaust pipe disposed downstream of the exhaust manifold 1 is accelerated, reducing their durability.

The present invention was developed in view of the conventional problems, and it is possible to heat the intake air without being affected by the engine cooling air, and it also prevents the exhaust manifold from being heated or kept warmer than necessary. The purpose of the present invention is to provide an engine intake air heating device that will never cause problems.

Therefore, in the engine intake air heating device according to the present invention, a hot air cover is provided that covers a part of the surface of the exhaust manifold to form a heating passage for the intake air, and the air inlet of the hot air cover is used to cool the engine. The present invention is characterized in that a radiation fin is opened on the downstream side with respect to the wind and is provided with a radiation fin extending along the engine cooling air at a position different from the position where the hot air cover is provided on the outer wall of the exhaust manifold.

Hereinafter, the present invention will be specifically explained with reference to the illustrated embodiments.

In Fig. 3, 10 is 10 in the longitudinal direction of the vehicle body.
multi-cylinder engine (not shown).

) provided for the exhaust gas inlet 10A1 gathering part 10
Exhaust manifold consisting of B1 exhaust gas outlet 10C,
11 is the upper wall surface 1 of the gathering part 10B of the exhaust manifold 10
0a along the longitudinal direction of the vehicle body, that is, the direction A of the engine cooling air, and covers the entire length of the hot air cover 13, which forms an intake air heating passage 12 with both sides closed between it and the upper wall surface 10a. An atmospheric air inlet 14 defined by the downstream end 11a with respect to the direction A of the engine cooling air of the hot air cover 11 is raised upward near the closed end 11b of the hot air cover 11 on the upstream side with respect to the direction A of the engine cooling air. The intake air outlet 15 formed as a cylindrical portion is a flexible intake air conduit that connects the outlet 14 and the middle of the intake air intake passage 17 of the air cleaner 16, and is connected to the downstream end of the hot air cover 11. The intake air introduced from the atmosphere inlet 13 formed in 11a is guided to the outlet 14 through the heating passage 12, and on the way,
This constitutes an intake air heating device that heats intake air using the heat of the exhaust manifold 10 and supplies the heated intake air from the outlet 14 to the air cleaner 16 via the conduit 15.

Furthermore, as shown in FIG.
A plurality of radiation fins 18° . ....

18 to ensure appropriate heat dissipation from the exhaust manifold 10.

In the case of the above configuration, the intake air introduced from the air intake port 13 is not stirred or diluted by the engine cooling air, and can therefore be efficiently heated, while the exhaust manifold 10 transfers only a portion of it to the hot air. Since it is covered with cover 11, exhaust manifold 1
The heat dissipation area of 0 becomes larger, and the exhaust manifold 10 can be prevented from overheating by engine cooling air such as running wind, especially at high speeds.As a result, the internal exhaust gas can be effectively cooled, and the exhaust gas is not heated to a higher temperature than necessary. It is possible to prevent thermal deterioration of the exhaust manifold 10 itself and the exhaust system downstream thereof, particularly the exhaust gas purification device and the exhaust pipe.

In addition, the hot air cover 11 is moved in the direction A of the engine cooling air.
Since the engine cooling air is provided along the exhaust manifold 10, it is possible to effectively heat the intake air and radiate heat from the exhaust manifold 10 effectively.

In addition, the heat radiation fin 18. ..., 18, the heat dissipation of the exhaust manifold 10 can be further improved.

In the above embodiment, a hot air cover is provided for the exhaust manifold of the engine, but it goes without saying that the hot air cover may be provided for an exhaust gas purification device such as a thermal reactor.

Furthermore, as shown by the imaginary line in FIG. 3, if the exhaust gas outlet 10C' of the exhaust manifold 10 is located at the rear of the exhaust manifold 10, the air near the atmosphere inlet 13 will be transferred to the exhaust gas outlet 10C'. Since the intake air is heated to some extent in advance by the air, the intake air can be heated even more effectively.

As described above, the present invention provides a hot air cover that partially covers the outer wall of the exhaust manifold, opens the atmosphere inlet of the hot air cover to the downstream side with respect to the engine cooling air, and provides hot air on the outer wall of the exhaust manifold. The present invention provides an engine intake air heating device characterized in that a radiation fin extending along the engine cooling air is provided at a position different from the position where the cover is provided.

Therefore, according to the present invention, the intake air can be heated without being affected by the engine cooling air, and the heat dissipation area of the exhaust manifold can be secured, so that the exhaust gas can be effectively cooled at high speeds. It is possible to achieve the effect that thermal deterioration of the exhaust system can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional explanatory diagram of an exhaust manifold showing a conventional engine intake air heating device, and Fig. 2 is an explanatory cross-sectional view of an exhaust manifold showing a conventional engine intake air heating device.
FIG. 3 is a cross-sectional explanatory view of the engine intake air heating device according to the present invention, and FIG. 4 is a cross-sectional view along line nm' in FIG. 3. 10...Exhaust manifold, 11...Hot air cover 12...Heating passage, 13...Atmospheric inlet, 1
8°..., 18...Radiating fin.

Claims (1)

[Scope of utility model registration request] In an engine intake air heating device that heats intake air using heat dissipation from an exhaust manifold, a hot air cover is provided that partially covers the outer wall of the exhaust manifold, and the air inlet of the hot air cover is connected downstream of the engine cooling air. An intake air heating device for an engine, characterized in that a heat radiation fin is opened only on the side and extends along the engine cooling air at a position different from the position where the hot air cover is provided on the outer wall of the exhaust manifold.