JP2002021566A - Cooler for construction machinery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate velocity unevenness in cooling air to enhance cooling efficiency for a heat-radiator equipment, and to prevent a turbulent flow from being generated inside a fan shroud to restrain generation of a noise. SOLUTION: Sloped faces 4g-4j are provided in axial fan side corner parts of the fan shroud 4 to be sloped toward blades of an axial fan 1, in a cooler for construction machinery wherein the heat-radiating equipments 2, 3 are arranged in an air-blowing downstream of the axial fan 1, and wherein the cooling air for the axial fan 1 is taken in through the fan shroud 4 extended rectangular-shapedly from core faces of the equipments 2, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for an engine room in a construction machine such as a hydraulic shovel or a rough terrain crane, and more particularly to a cooling device for a construction machine that cools a heat radiating device using a push-in axial fan. Things.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
In a hydraulic shovel having an upper revolving structure 41 rotatably mounted thereon, a cabin 42 serving as a cockpit is disposed in front of the upper revolving structure 41, and an engine room 43 is disposed in a rear portion.

The heat radiating device in the engine room 43 is
Push-in axial fan (hereinafter referred to as cooling fan) 44
In a cooling device that cools using an oil cooler, an oil cooler 46 and a radiator 47, which are radiators, are provided downstream of a cooling fan 44 that is rotationally driven by an engine 45, and the cooling air from the cooling fan 44 is cooled by the oil. Cooler 4
6, a rectangular tubular fan shroud 48 for guiding to the radiator 47 is provided.

In such a cooling device, when the cooling fan 44 is driven to rotate, the intake port 4 of the engine cover 49 is rotated.
After the outside air is taken into the engine room 50 from the engine 9a and cools the engine 45 and the like, the cooling air passing through the cooling fan 44 is passed through the fan shroud 48 to the oil cooler 4.
6. The heat is introduced into the radiator 47 and heat exchange is sequentially performed.

[0005] The warm air heated by the heat exchange is discharged to the outside through an exhaust port 49b provided on a side surface of the engine cover 49. In the drawing, reference numeral 51 denotes a duct for guiding the warm air that has passed through the radiator 47 to the exhaust port 49b.

The fan shroud 4 in the above cooling device
8, one end is extended from the core surface (radiation surface) of the radiator 47 in a rectangular tube shape, and the other end is configured so that the cooling air sent from the cooling fan 44 can be efficiently guided to the radiator devices 46 and 47. The cooling fan 44 surrounds an outer peripheral portion of the fan blade and covers part of the fan blade in the axial direction of the cooling fan 44.

FIG. 5 shows the cooling fan 44 and the heat radiating device 4.
6 and 47 are shown in an enlarged manner. In the figure, the fan shroud 48 is formed into a box shape by pressing a steel plate or by welding a plurality of steel plate pieces, and the cooling fan 44 is inserted into the front wall surface 48a of the fan shroud 48. Circular opening 48 to get
b is formed. Since the excavator usually performs work such as excavation in a stopped state, the temperature in the engine room rises significantly. Therefore, a steel plate that does not generate thermal deformation is selected as the material of the fan shroud 48 in the sense of preventing thermal deformation, and is formed into a box shape because processing is easy. In addition, a part of the fan shroud bottom surface is formed on the inclined surface 48c for the purpose of improving appearance and improving maintainability.

[0008]

However, in the above-described conventional cooling device, the speed component in the cooling fan radial direction in the cooling air generated from the cooling fan 44 increases as the position approaches the fan blade tip, and the cooling fan axial direction increases. Since the core surfaces of the radiator 47 and the oil cooler 46 overlap, a speed distribution occurs. Further, the cooling fan 44
The cooling air that has passed through the cooling fan 44 due to the influence of the arrangement of the heat radiating devices 46 and 47 does not flow uniformly, thereby lowering the heat radiation efficiency of the heat radiating device.

In the box-shaped fan shroud 40, the cooling air stays in the corners in a turbulent state, causing not only a decrease in cooling efficiency but also noise generation.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems of the conventional cooling device in construction equipment. A first object of the present invention is to improve the cooling efficiency of the heat radiating device by eliminating the unevenness in the speed of the cooling air. In particular, a second object is to prevent turbulence in the fan shroud and suppress generation of noise.

[0011]

According to a first aspect of the present invention, a heat radiator is disposed on the downstream side of the fan of the axial flow fan, and the shaft is extended through a fan shroud extending in a rectangular cylindrical shape from a core surface of the heat radiator. In the cooling device for a construction machine configured to take in the cooling air of the flow fan, the flow of the cooling air discharged in the radial direction from the axial flow fan to the axial flow fan-side corner of the fan shroud is controlled by the heat radiation device. This is a cooling device for a construction machine having an inclined surface facing a heat radiation surface.

According to a second aspect of the present invention, there is provided a cooling device for a construction machine, wherein the inclined surface is formed such that each corner of the fan shroud on the axial fan side is cut off in a triangular shape.

According to a third aspect of the present invention, there is provided a cooling device for a construction machine, wherein the heat radiating device includes a radiator and an oil cooler disposed upstream of the radiator for blowing air.

According to a fourth aspect of the present invention, there is provided a cooling device for a construction machine in which a sound absorbing material is attached to an inner wall surface of the fan shroud.

According to the first aspect of the present invention, when the axial fan is driven to rotate, the cooling air sent from the axial fan flows through the fan shroud and comes into contact with the heat radiating device, thereby performing heat exchange. Part of the swirl flow sent from the cooling fan is
Although flowing in the radial direction of the cooling fan, it flows along the inclined surface formed at the corner of the fan shroud, and is introduced into the heat dissipation device without losing the turning energy. As a result, it is possible to eliminate the flow of the cooling air that has been generated by generating turbulent flow at the corners in the fan shroud, and the cooling air can be introduced into the heat radiating device as a rectified cooling air. Efficiency can be improved.

According to the second aspect of the present invention, since a triangular inclined surface is formed at each corner of the fan shroud on the axial fan side, heat is smoothly radiated without losing the momentum of the axial fan swirling component. Can be introduced into equipment.

According to the third aspect of the present invention, since the cooling air which has been staying in the past can be introduced into the radiator in a rectified state, the radiator and the oil cooler overlap in the axial direction of the cooling fan. Can be compensated for the decrease in cooling efficiency.

According to the fourth aspect of the present invention, the sound absorbing material attached to the inner wall surface of the fan shroud absorbs noise caused by cooling air generated in the fan shroud, thereby preventing generation of noise. You.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

FIG. 1 shows an embodiment of a cooling device for a construction machine according to the present invention.

In FIG. 1, reference numeral 1 denotes a cooling fan that is driven to rotate in the direction of arrow a by an engine (not shown). The arrow b indicates the flow of cooling air taken in from the intake port (not shown) of the engine cover by the cooling fan 1.

An oil cooler 2 and a radiator 3 as heat dissipating devices are arranged in this order downstream of the cooling fan 1 to form a push-in type cooling system.
Further, the center of the radiator 3 is disposed substantially on the extension of the axis of the cooling fan 1, and the core surface of the radiator 3 is larger than that of the oil cooler 2, and the oil cooler 2 is located above the core surface of the radiator 3 and substantially at the center. Are located in

The heat radiating devices 2 and 3 and the cooling fan 1 are connected by a rectangular-shaped fan shroud 4 having a small height, and the cooling fan 1 is arranged in front of the fan shroud 4.

Reference numeral 5 denotes a duct connecting the radiator 3 to an exhaust port (not shown) of the engine cover. The duct 5 guides and discharges hot air heated by heat exchange to the outside of the engine room. ing.

The fan shroud 4 has an upper surface 4a, a right side surface 4b, a left side surface 4c, and a lower surface 4d. A circular opening 4f through which the cooling fan 1 can be inserted is formed in the center of the front surface 4e.

At each corner of the fan shroud 4, inclined surfaces 4 g, 4 h, 4 i, 4 j which are inclined from the corners of the core surface of the radiator 3 toward the fan blades of the cooling fan 1 are formed. However, FIG. 1 does not show the inclined surface 4h corresponding to the cutout portion (the inclined surface 4h).
See FIG. 2 for details).

In FIG. 2, the inclination angle θ of the inclined surface 4h is formed to be 45 ° downward and inward from the virtual outline L in the z-axis direction in this embodiment.
The sides are formed to have the same length. The inclination angle θ is determined in consideration of the thickness d, width, and height of the fan shroud 4, the distance from the center of the circular opening 4f to the outer peripheral edge of the radiator 3, and the like.
It is determined in the range of °.

The operation of the cooling device having the above configuration will be described below.

When the engine is driven and the cooling fan 1 is driven to rotate, for example, outside air is taken in from an intake port of an engine cover, and cooling air b is sent out from the cooling fan 1.

The cooling air b flows in the axial direction of the cooling fan 1 and travels toward the heat radiating devices 2 and 3. A part of the cooling air, that is, a part of the swirling flow generated by the rotation of the cooling fan 1 is cooled. It flows in the radial direction of the fan 1.

At this time, in the conventional fan shroud,
The swirling flow flowing in the radial direction generates a turbulent flow at a corner of the fan shroud and causes stagnation, but in the fan shroud 4 of the present invention, the inclined surfaces 4g to 4g
Since j is formed, the cooling air having a swirl component flows along the inclined surfaces 4g to 4j and is guided to the heat radiating devices 2 and 3. As a result, the cooling air stays in the fan shroud 4 is eliminated, and the swirling flow flowing in the radial direction can be used for heat exchange between the heat radiating devices 2 and 3.

FIG. 3 shows the heat radiation effect of the cooling device according to the present invention in comparison with the heat radiation effect of the conventional cooling device.

In the figure, the graph d1 is the radiator 3
And the required heat radiation amount of the oil cooler 2, which is a standard value. Note that the radiator 3 circulates cooling water inside the engine to directly cool the engine.
It is determined based on the engine calorific value. On the other hand, the required heat radiation amount of the oil cooler 2 is determined based on a ratio of the working oil supplied to the hydraulic circuit, which is not used for work and changes into thermal energy.

The graph d2 shows the amount of heat radiation by the conventional cooling device. As shown in the graph, the amount of heat radiation of the oil cooler appears high, but the amount of heat radiation of the radiator disposed downstream thereof is lower than the required amount of heat radiation.

That is, in a portion where the core surface of the radiator overlaps with the core surface of the oil cooler as viewed from the cooling fan side, the cooling air passes through the core surface of the radiator after the heated air having passed through the oil cooler. Because
The temperature difference with the cooling water flowing in the radiator becomes smaller,
As a result, the amount of heat exchange decreases.

The graph d3 shows the amount of heat radiation by the cooling device of the present invention.

When an inclined surface is formed at each corner of the fan shroud 4, the cooling air is introduced into the heat radiating devices 2 and 3 in a state close to rectification without staying at the corner of the fan shroud 4. 2. Both the radiator 3 and the radiator 3 have a heat radiation amount exceeding the required heat radiation amount. This indicates that the inclined surfaces 4g to 4j formed at the corners of the fan shroud 4 can radiate heat from the heat radiating devices 2 and 3 in a well-balanced manner.

The graph d4 shows the fan shroud 4
The amount of heat radiation when the inclined surfaces 4i and 4j are formed at the lower two places is shown as a comparative example. In this case, the radiator exceeded the required heat dissipation, but the oil cooler could not satisfy the required heat dissipation.

This means that the corners 3 of the fan shroud 4
Even if an inclined surface is formed at a location, if a stagnation area of the cooling air remains at the remaining one location, turbulence occurs in the stagnation area, disturbing the rectification state of the cooling wind, and as a result, the amount of heat radiation decreases. Expected. Therefore, it is preferable to form the inclined surfaces 4g to 4j at each corner of the fan shroud 4.

Conventionally, if a predetermined amount of heat radiation cannot be obtained due to restrictions on the shape, size, rotation speed, etc. of the cooling fan,
A method has been adopted in which the size of the oil cooler is increased in anticipation of the decrease in the amount of heat radiation. In that case, a decrease in the amount of heat radiation of the radiator is inevitable for the above-described reason. However, according to the present invention, since the heat radiation efficiency of both the oil cooler 2 and the radiator 3 can be improved, it is not necessary to increase the size of the oil cooler, and it is possible to obtain a predetermined heat radiation amount with a restricted cooling fan. it can.

It is preferable that a glass wool mat as a sound absorbing material is attached to the inner wall surface of the fan shroud 4. Further, it is preferable to use a glass wool mat having water repellency. As a method of fixing the glass wool, for example, a method of fixing the glass wool via a plurality of anchor pins planted on the inner wall surface of the fan shroud, a method of fixing the glass wool to the inner wall surface of the fan shroud using an adhesive, and the like are shown.

When the sound absorbing material is attached in this manner, noise caused by the cooling air generated in the fan shroud 4 is absorbed, so that generation of noise is prevented.

In the above-described embodiment, the case where the corner of the fan shroud 4 is formed by an inclined surface is exemplified. However, a block having an inclined surface of the same shape as the above-mentioned inclined surface is formed at the inner corner of the existing box-shaped fan shroud. May be mounted as a separate component. According to this configuration, the effects of the present invention can be obtained for a conventional fan shroud.

[0044]

As is apparent from the above description,
According to the first aspect of the present invention, when the axial fan is driven to rotate, the cooling air flows through the fan shroud and contacts the heat radiating device to perform heat exchange. However, the cooling air flowing near the fan shroud inner wall is Since it flows along the inclined surface formed in a state inclined toward the wing, turbulence does not occur at the corners inside the box-shaped fan shroud and cooling air does not stay, and the rectified cooling air radiates heat The heat dissipation efficiency is improved by being introduced into the equipment.

According to the second aspect of the present invention, a triangular inclined surface is formed at each corner of the fan shroud on the axial fan side, so that the cooling air flowing in the radial direction can be smoothly moved without losing its momentum. Can be introduced to heat radiating equipment.

According to the third aspect of the present invention, since the cooling air that has been staying in the past can be introduced into the heat radiating device in a rectified state, the radiator and the oil cooler overlap in the axial direction of the cooling fan. Can be compensated for the decrease in cooling efficiency.

According to the fourth aspect of the present invention, the sound absorbing material attached to the inner wall surface of the fan shroud absorbs noise caused by the cooling air generated in the fan shroud, thereby preventing generation of noise. You.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a cooling device for a construction machine according to the present invention, with a part thereof being cut away.

FIG. 2 is an enlarged view of a corner of the fan shroud shown in FIG.

FIG. 3 is a graph comparing a heat radiation amount according to the present invention with a heat radiation amount according to a conventional example.

FIG. 4 is a cross-sectional view illustrating a configuration of a cooling device in a conventional construction machine.

FIG. 5 is an enlarged perspective view showing a configuration around the heat radiating device shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cooling fan 2 Oil cooler 3 Radiator 4 Fan shroud 4g, 4h, 4i, 4j Inclined surface 5 Duct

Claims (4)

[Claims] 1. A heat radiating device is arranged on the downstream side of the blower of an axial fan, and cooling air of the axial fan is taken in through a fan shroud extending in a rectangular cylindrical shape from a core surface of the heat radiating device. In the cooling device for a construction machine, the fan shroud may be provided with an inclined surface for directing a flow of cooling air discharged in a radial direction from the axial flow fan to a heat radiation surface of the heat radiating device, at an axial fan side corner portion. A cooling device for construction machinery. 2. The cooling device for a construction machine according to claim 1, wherein the inclined surface is formed so as to cut off an axial fan side corner of the fan shroud in a triangular shape. 3. The cooling device for a construction machine according to claim 1, wherein the heat radiating device includes a radiator and an oil cooler disposed upstream of the radiator. 4. The cooling device for a construction machine according to claim 1, wherein a sound absorbing material is attached to an inner wall surface of the fan shroud.