Heat exchange – With vehicle feature
Reexamination Certificate
1999-08-19
2002-08-20
Ciric, Ljiljana (Department: 3743)
Heat exchange
With vehicle feature
C165S051000, C165S149000, C180S068100, C180S068400, C123S041490, C123S041510
Reexamination Certificate
active
06435264
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a cooling system for a wheel type working vehicle having a working implement in the front and an engine in the rear.
DESCRIPTION OF THE PRIOR ART
FIG. 10
is a side elevation of a wheel type working vehicle. This working vehicle, generally indicated by reference numeral
1
, has a vehicle body
2
. A working implement
3
used for scooping and loading is mounted in the front of the vehicle body
2
. An engine compartment
10
incorporating an engine
4
and a radiator
50
is disposed in the rear of the vehicle body
2
. The engine compartment
10
consists of a hood
11
, a pair of side covers
12
spaced from each other, and a radiator shutter
13
. Each side cover
12
is provided with an intake port
14
. The radiator shutter
13
is provided with exhaust ports
15
.
FIGS. 11 and 12
are schematic plan views showing examples of the prior art working vehicle. In
FIG. 11
, a cooling fan
20
is positioned behind the engine
4
. The radiator
50
is located behind the fan. The cooling fan
20
is directly driven by the engine
4
. In
FIG. 12
, the radiator
50
is disposed behind the engine
4
, and the cooling fan
20
is mounted behind the radiator
50
. In this arrangement, the cooling fan
20
is driven either by a hydraulic motor or by an electric motor
21
. Cooling air is sucked from the intake ports
14
in the right and left side covers
12
of the engine compartment
10
as indicated by the arrows. The air then passes through the radiator
50
and is discharged from the exhaust ports
15
of the radiator shutter
13
. Another example is disclosed in Japanese Unexamined Utility Model No. 83126/1989.
The structures described above have the following problems. In the examples shown in
FIGS. 11 and 12
, the flow of the cooling air is indicated by the arrows. That is, the cooling air enters the radiator
50
after passing across the side surfaces of the engine
4
. Therefore, the cooling air is prewarmed. Furthermore, the cooling airflow is not smooth because the engine
4
constitutes an obstacle. Hence, the cooling efficiency is not good. For this reason, the radiator
50
needs to have a large surface area. Furthermore, a large amount of airflow is necessary. Additionally, the rotational speed of the cooling fan
20
is high.
In recent years, noises have presented great social problems. Working vehicles have been required to produce reduced levels of noise. One method of reducing the noise level is to lower the rotational speed of the cooling fan
20
. For this purpose, it is necessary to improve the cooling efficiency. One method of improving the cooling efficiency is to increase the cooling area of the radiator
50
. One conceivable method of increasing the cooling area consists of increasing the height, width, or thickness of the radiator
50
. Where the height or width is increased, however, the flow of air across the increased portion is poor. This will impair the efficiency of the cooling fan
20
. Where the thickness is increased, the ventilation resistance is increased, and the cooling efficiency drops. Where the height of the radiator
50
is increased, the height H
1
of the hood
11
of the engine compartment
10
shown in
FIG. 1
increases, deteriorating the backward visibility. If the width is increased, the width of the vehicle is increased.
A wheel loader that is a wheel type working vehicle that usually performs the following operations. First, the loader scoops a hillock. Thereafter, the loader moves backward while the operator is steering the vehicle. Then, the vehicle advances to a location where the soil should be dumped. Therefore, if the backward visibility is deteriorated as mentioned above, it is difficult to drive the vehicle in the backward direction. If the width of the vehicle is increased, the vehicle more easily collides against an obstacle during steering or motion. As a result, the steering performance and the working performance are deteriorated.
In the structure described above, the engine
4
, the radiator
50
, and the cooling fan
20
are close to each other. The cooling fan
20
is fixed. Therefore, it is difficult to clean the front and rear surfaces of the radiator
50
.
In the structure disclosed in the above-cited Japanese Unexamined Utility Model No. 83126/1989, the core of the radiator is split into two parts. One core part is tilted from the other. The cooling area can be increased without increasing the height or width of the vehicle body. However, tanks formed in the core parts are placed in communication with each other and made integral with each other. Consequently, the structure is made complex and expensive. Furthermore, when the radiator is replaced, the whole radiator must be replaced. Hence, it is costly to repair the cooling system.
SUMMARY OF THE INVENTION
In view of the foregoing problems, it is an object of the present invention to provide an inexpensive cooling system which is used to cool a working vehicle, secures a large cooling area within a limited space, produces a reduced level of noise, can offer improved backward visibility, and is easy to clean.
The above-described object is achieved by a first embodiment of the present invention that provides a cooling system for use with a wheel type working vehicle having a working implement in the front and an engine in the rear. The cooling system has a plurality of radiators mounted in the rear of the vehicle. The radiators are arranged like the letter “V” within a plane.
In the structure described above, the plural radiators are arranged like the letter “V” within a plane. Therefore a wider cooling area can be secured within the same width than where a single radiator is used. The rotational speed of the fan can be reduced. Consequently, a lower level of noise can be accomplished. Furthermore, air taken in across the side covers of the engine compartment flows smoothly and can be introduced without passing across the side surfaces of the engine. Hence, the cooling efficiency is improved. Especially in the case of large-sized vehicles, the cost can be reduced by using two small-sized radiators.
A second embodiment of the present invention is based on the first embodiment described above and characterized in that the plural radiators described above are arranged like the letter “V” in the rear of the engine. This V-shaped radiator arrangement has a space or an opening in the rear. A single cooling fan is mounted in the opening of the radiator arrangement.
In the structure described above, the radiators are arranged like the letter “V” having an opening in the rear and so the radiators are tilted from the side surface of the body. The single cooling fan is mounted in the opening of the V-shaped radiator arrangement. Therefore, air taken in across the side surfaces of the vehicle body flows smoothly. The cooling air passes across the whole surfaces of the radiators while experiencing less resistance. In consequence, the cooling efficiency is improved.
A third embodiment of the present invention is based on the second embodiment described above and characterized in that each of the side surfaces of the radiators described above has an intake port covered by a side cover that can be opened. The top side of the intake port is covered by the hood whose top surface is tilted rearwardly downwardly.
In the structure described above, the radiators are tilted from the side surfaces of the vehicle body. Therefore, the outer surfaces of the radiators can be inspected and cleaned easily by opening the side covers. Furthermore, the rearward visibility is improved, because the top surface of the hood is tilted rearwardly and downwardly. Hence, the vehicle can be driven easily and safely.
A fourth embodiment of the invention is based on the second or third embodiment described above and characterized in that the aforementioned cooling fan is tilted rearwardly and upwardly as viewed from a side.
In this structure, the cooling fan is tilted rearwardly upwardly and so the height at the rear end of the hood can be reduced
Konno Osahiro
Sagara Kazuyuki
Tanaka Yutaka
Ciric Ljiljana
Komatsu Ltd.
Varndell & Varndell PLLC
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