JPH03118218A - Over-heat preventive device for bonnet for engine room - Google Patents

Abstract

PURPOSE:To efficiently prevent a bonnet from being over-heated by arranging a heat insulating plate apart from a ventilation space in the inside of the bonnet covering an engine room, and thereby constituting the specified parts of the ventilation space and the heat insulating plate to be in a slant raised up afterward respectively. CONSTITUTION:In an engine room covered by a bonnet B, an engine E and a muffler 2 are arranged. And a heat insulating means 7 is disposed in the inside which roughly covers the whole of the surfaces of the front wall 3, the right and left side walls 4 and the upper wall 6 of the bonnet B. In this case, the major section of the heat insulating means 7 is formed in such a way that a heat insulating plate 10 is disposed apart from a ventilation space 8 in the inside of the bonnet 8. And furthermore, the upper wall 6, the upper section of a ventilation space 11 and the upper wall 12 of the heat insulating plate are constituted to be in a slant raised up afterward respectively. In addition, the ventilation inlet 13 of the ventilation space 8 is opened at a bonnet wall 3 in the lower portion 15 of the front section 14 of the space. And furthermore, a ventilation outlet 16 of the ventilation space 8 is opened at the rear section 18 of the bonnet upper wall 6 in the rear portion 17 of the upper section of the space 11.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a device for preventing overheating of the bonnet of the engine room in an engine room of a tractor, a motor generator, a soundproof type vehicle unit, etc. To provide a device that can efficiently prevent overheating of a bonnet by releasing heat in a room.

<Prior art> The basic structure of the engine room bonnet overheat prevention device that is the subject of the present invention is that the engine room
and a muffler 2, cover the engine room 1 with a bonnet B, make the muffler 2 face the bonnet B, and at least the upper portion 5 and the upper wall 6 of the front wall 3 and left and right side walls 4 of the bonnet B. Heat insulation means 7 on the inside covering the entire surface
It is of a format with the addition of.

As shown in FIG. 3, this type of conventional technology includes, for example, in the engine compartment 1 of a garden tractor equipped with a vertical water-cooled engine E, (1) a heat insulating material 50 such as glass wool is installed on the inner wall of the bonnet B; (2) A heat shield plate 51 is further stretched on the inside of the heat insulating material 50 so as to surround the engine E and the muffler 2 (see imaginary line), and the heat insulating means 7 is There is something configured.

<Problems to be Solved by the Invention> However, in the above-mentioned conventional technology, since the heat insulating material is spread around the inside of the bonnet B, the heat generated by the muffler 2 and the engine body is not transmitted to the outer surface of the bonnet L-B. (
Although this suppresses the overheating of the bonnet B, it becomes difficult to radiate from the inside of the engine room 1 to the outside and tends to stay inside the room, so there is a risk that the inside of the engine room 1 will overheat when the engine E is operated under high load. There is.

A technical problem of the present invention is to efficiently release heat in the engine compartment 1 and prevent overheating of the bonnet.

Means for Solving the Problems> Means for solving the above problems will be described below using drawings corresponding to embodiments.

That is, the present invention provides an overheat prevention device for an engine compartment bonnet having the above-mentioned basic structure, in which the heat insulating means 7 includes a heat insulating plate 10 provided inside the bonnet B with a ventilation space 8 in between, and the upper wall 6 of the bonnet B; Upper part 11 of ventilation space 8
The upper wall portion 12 of the heat shield plate 10 is formed in three places in a rearward upward slope, and the ventilation inlet 13 of the ventilation space 8 is connected to the front portion 14 of the ventilation space 8.
The opening is made in the front wall 3 of the bonnet B at the lower part 15 of the bonnet B, and the ventilation outlet 16 of the ventilation space 8 is opened in the upper part 11 of the ventilation space 8.
It is characterized by opening into the rear part 18 of the upper wall 6 of the bonnet B at the position of the rear part 17 of the bonnet B.

<Function> The heat insulating plate 10 is provided inside the bonnet B with the ventilation space 8 in between, and predetermined portions of the bonnet B, the ventilation space 8, and the heat insulating plate 10 are each formed in a rearward upwardly inclined shape, so that the muffler 2
The heat generated from the engine body heats the air in the ventilation space 8 via the heat shield plate 10, and the warmed air flows into the ventilation space 8.
It is guided in an upwardly inclined direction along the upper part 11 of the air ventilator and is discharged to the outside through the ventilation outlet 16.

As a result, the ventilation space 8 is expanded from the ventilation inlet 13 to the ventilation outlet 16.
A flow of air is formed towards the engine room 1, and this air convection carries away the heat in the engine room 1 to the outside via the heat insulating plate lO, so that the influence of heat from the muffler 2 and the engine body on the bonnet B can be reduced, and the engine Prevent overheating in room 1.

<Effects of the Invention> (1) Heat generated in the engine room is carried away from the ventilation outlet to the outside by the convection of air blowing through the ventilation space, so heat does not accumulate in the engine room unlike the conventional technology, and the engine can be heated to high temperatures. Even when operating under load, overheating in the engine compartment under the hood is prevented, eliminating the risk of burns to workers.

(2) Just install a heat shield under the specified conditions inside the bonnet with a ventilation space between them, so the tractor, motor generator,
It can be easily applied to existing engine compartments with bonnets for power units, etc., and has a simple structure and can be implemented at low cost despite its strong overheat prevention effect.

<Example> Hereinafter, embodiments of the present invention will be described based on the drawings.

Fig. 1 is a longitudinal left side view of the garden tractor, and Fig. 2 is a schematic longitudinal sectional front view of the same tractor. A vertical water-cooled engine E is housed inside, and a radiator 20 is arranged behind the engine E.A cylindrical muffler 2 is horizontally connected to the upper part of the exhaust manifold 21 of the engine E, and the front and upper parts thereof is covered with a heat shield plate 22 to face the bonnet I-B, and an exhaust outlet passage 23 of the muffler is led out to the front lower part 24 in a front curved shape.

Reference numeral 24 denotes an air cleaner led out in front of the engine E.

On the other hand, a heat insulating plate 10 is provided inside the bonnet B with a ventilation space 8 in between, and a ventilation inlet 13 is provided at the front lower part of the ventilation space 8.
, and a ventilation outlet 16 is provided at the upper rear thereof.

That is, as shown in FIGS. 1 and 2, the bonnet B and the heat insulating plate 10 are formed to have a constant thickness, and the heat insulating plate 10 is attached to the upper half 5 of the front wall 3 and both left and right side walls 4 of the bonnet B. and provided over almost the entire surface of the upper wall 6, surrounding the upper part of the engine E and the muffler 2 with a heat insulating plate 10, and separating the bonnet B and the heat insulating plate 10 with a ventilation space 8,
A bonnet B, a ventilation space 8, and a heat insulating plate 10 are formed in an inclined shape upward at the rear.

Then, as shown in FIG. 1, the ventilation inlet 1 of the ventilation space 8
3 is opened in the front wall 3 of the bonnet B at a position of the lower part 15 of the front part 14 of the ventilation space 8, and a ventilation outlet 16 of the ventilation space 8 is opened.
is opened in the rear part 18 of the upper wall 6 of the bonnet B at the position of the rear part 17 of the front part 14 of the ventilation space 8.

Therefore, to explain the function of this embodiment, the heat generated from the muffler 2 and the engine body heats the air in the ventilation space 8 via the heat shield plate 10, and the warmed air flows backward and upward along the ventilation space 8. and is discharged to the outside from the ventilation outlet 16.

Therefore, the ventilation space 8 has a ventilation inlet 13 to a ventilation outlet 16.
A flow of outside air is created, and while blowing through the ventilation space 8, the outside air carries away the heat in the engine room 1 to the outside via the heat shield 10, so that the heat from the muffler 2 and the engine body is transferred to the outside of the bonnet B. It's hard to convey (Naru).

As a result, heat does not accumulate in the engine compartment 1 as in the prior art, and even when the engine E is operated under high load, overheating in the engine compartment 1 is efficiently prevented.
Eliminates the risk of burns to workers.

In the present invention, instead of placing a heat insulating material on the inside of the bonnet B, the ventilation space 8 is formed in a raised rear shape to create a flow of outside air, and the heat inside the engine room 1 is carried away by the convection of this air. For example,
Only the upper wall portion 12 of the heat insulating plate 1O may be formed in an upwardly inclined shape, and the lower wall thereof may be formed flat.

In addition, the ventilation space 8 is not limited to being formed in a cylindrical shape with a constant passage cross-sectional area from the ventilation inlet 13 to the ventilation outlet 16. It may be formed in an upwardly sloping shape.

Furthermore, the present invention is not limited to agricultural machines such as tractors as described in the above embodiments, and is not limited to engine working machines such as construction machines, motor generators, engine compressors, and engine weltanato. It can also be applied to items such as a power unit housed alone in a soundproof case with a bonnet.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a longitudinal left side view of a garden tractor, FIG. 2 is a schematic longitudinal sectional front view of the same tractor, and FIG. It is a figure equivalent figure. B...Bonnet, E...Engine, 1...Engine room, 2...Muffler, 3...Front wall of B, 4...
...Left and right side walls of B, 5...Upper part of 4, 6...
Upper wall of B, 7. Heat insulation means, 8. Ventilation space, 1o.
...Heat insulation plate, upper part of 11.8, upper wall part of 12...1o, front part of ventilation inlet 14...8 of 13...8, lower part of 15...14, 16. ...Ventilation outlet of 8, ]7...] Rear of 1, 18...Rear of 6. Figure 3

Claims (1)

[Claims] 1. An engine E and a muffler 2 are installed in an engine room 1, the engine room 1 is covered with a bonnet B, the muffler 2 is made to face the bonnet B, and the front wall 3 of the bonnet B, left and right In an overheat prevention device for an engine compartment bonnet, the heat insulating means 7 is provided on the inside of at least the upper portions 5 of the side walls 4 and substantially the entire surface of the upper wall 6. A heat insulating board 10 is provided across the ventilation space 8, and three places, the upper wall 6 of the bonnet B, the upper part 11 of the ventilation space 8, and the upper wall part 12 of the heat insulating board 10, are formed in an upwardly inclined shape, so that the ventilation space 8 The ventilation inlet 13 of the ventilation space 8 is connected to the front part 14 of the ventilation space 8.
The opening is made in the front wall 3 of the bonnet B at the lower part 15 of the bonnet B, and the ventilation outlet 16 of the ventilation space 8 is opened in the upper part 11 of the ventilation space 8.
An overheating prevention device for an engine room bonnet, characterized in that it opens in the rear part 18 of the upper wall 6 of the bonnet B at the rear part 17 of the engine compartment.