JP3210284B2 - Cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the cooling effect of an engine cooling system as well as to prevent overheating while keeping the size of the system from becoming larger. SOLUTION: In this cooling system, a heat exchanger 5 for cooling is placed within an air duct for an outer air 3 used for cooling which is generated by a fan 4 rotated by an engine 1, and an evaporator 21 for the freezing cycle is located on the windward side of the heat exchanger 5 for cooling. A condenser 22 for the freezing cycle is placed on the downwind side of the heat exchanger 5 for cooling. A compressor 23 for the freezing cycle is driven by the engine. The heat exchanger 5 for cooling is comprised of a radiator 6 which cools cooling water of the engine 1 and an oil cooler 8 which cools the hydraulic fluid of a pump 7.

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 cooling an engine used in, for example, a construction machine.

[0002]

2. Description of the Related Art FIG. 3 shows a cooling device for an engine 1 mounted on a construction machine such as a hydraulic shovel. A fan 4 for forming an air passage for cooling external air 3 on a rotating shaft 2 of the engine 1 is shown. Is provided, and a cooling heat exchanger 5 is disposed in an air passage generated by the fan 4. The cooling heat exchanger 5 includes a radiator 6 that cools cooling water of the engine 1 and an oil cooler 8 that cools hydraulic oil of a pump 7 driven by the engine 1.

[0003] Cooling water circulates through the engine 1 and the radiator 6. The hydraulic oil is discharged from the pump 7, the direction and the flow are controlled by the control valve 9, the various actuators 10 used in the construction machine are operated, the oil is cooled by the oil cooler 8, and discharged to the tank 11. , The pump 7.

[0004] Cooling outside air 3 is introduced by a fan 4 rotated by the engine 1, and the working oil of the oil cooler 8 and the cooling water of the radiator 6 are cooled by the cooling outside air 3.

[0005]

Normally, the operating oil is 90
° C, and the cooling water is overheated at 100 ° C. Therefore, if the temperature of the outside air for cooling 3 rises to 40 ° C or 50 ° C, the cooling efficiency decreases, and the amount of heat that the outside air for cooling 3 can take from the radiator 6 and the oil cooler 8 is extremely large. It becomes smaller and easily overheats.

In order to prevent overheating, conventional construction machines must take measures such as increasing the size of cooling devices such as the radiator 6 and the oil cooler 8 and increasing the amount of air introduced from outside.

For this reason, the space efficiency of the cooling device deteriorates and the problem of cost increase arises. In addition, when the rotation speed of the fan 4 is increased to increase the air flow, noise increases, and furthermore, the engine room becomes large. The intake and exhaust holes of the enclosure to be covered become large, and a design problem also arises.

Conventionally, since the outside air is introduced as it is, dust radiated from the outside air tends to clog the cooling fins of the cooling device, which may lower the cooling efficiency. And maintenance is troublesome.

On the other hand, in order to extend the interval of the maintenance, there is a case where a cooling device is used in which the interval between the heat dissipating fins is increased to make the mesh coarser. However, there is a problem that the cooling efficiency is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to improve the cooling efficiency of a cooling device, to prevent overheating while suppressing the size of the cooling device, and to make the cooling device maintenance-free. It is intended to aim at.

[0011]

According to a first aspect of the present invention, there is provided a fan which is rotated by an engine and introduces outside air for cooling toward the engine, and a fan for cooling air which is introduced by the fan. And a cooling cycle evaporator arranged on the windward side of the cooling heat exchanger.

Even when the outside air temperature is high, the outside air temperature is lowered by the evaporator of the refrigeration cycle disposed on the windward side of the cooling heat exchanger, and the cooling heat exchanger is efficiently cooled by the low-temperature cooling outside air. .

According to a second aspect of the present invention, there is provided the cooling device according to the first aspect, further comprising a refrigeration cycle condenser disposed downstream of the cooling heat exchanger.

The cooling air generated by the fan of the engine cools the condenser of the refrigeration cycle disposed on the leeward side of the cooling heat exchanger, so that a special cooling means for securing the condensation action in the condenser is provided. There is no need to provide

According to a third aspect of the present invention, there is provided the cooling apparatus according to the first or second aspect, further including a compressor of a refrigeration cycle driven by an engine.

Since the compressor of the refrigeration cycle is driven by the engine, there is no need to provide a dedicated compressor driving means.

According to a fourth aspect of the present invention, in the cooling device according to any one of the first to third aspects, the cooling heat exchanger is driven by the radiator for cooling the cooling water of the engine and the engine. And an oil cooler for cooling the working oil of the pump.

Then, the engine cooling water of the radiator and the working oil of the oil cooler are simultaneously cooled by the common cooling air generated by the fan of the engine.

The invention described in claim 5 is based on claim 1,
In the cooling device according to any one of Items 3 and 4, a hood cover that covers the cooling heat exchanger having the radiating fins and the evaporator and has a suction port on the upstream side of the evaporator is connected to the suction port of the hood cover. And an air cleaner for cleaning the outside air for cooling.

Then, only the outside air cleaned by the air cleaner is supplied from the suction port of the hood cover to the evaporator and the cooling heat exchanger in the hood cover to cool them.

According to a sixth aspect of the present invention, in the cooling device of the fifth aspect, the air cleaner and the suction port of the hood cover are connected by an air duct, and the fan is provided by the hood cover together with the evaporator and the cooling heat exchanger. It is covered.

Since the outside air for cooling from the air cleaner to the fan passes through the inside of the air duct and the hood cover, the noise generated when passing through the evaporator and the heat exchanger for cooling is not easily leaked to the outside, and the hood cover is protected from noise. The noise generated from the fan can be reduced by the rectifying action.

According to a seventh aspect of the present invention, in the cooling device according to the fifth or sixth aspect, the condenser of the refrigeration cycle disposed outside the hood cover is provided separately from the engine provided opposite to the condenser. And a sub-fan rotated by the driving means.

Then, the condenser is cooled by the sub-fan having an appropriate and stable speed which is not affected by the engine speed.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to one embodiment shown in FIG. 1 and another embodiment shown in FIG.

As shown in FIG. 1, a fan 4 for introducing cooling external air 3 toward the engine 1 is provided on the rotating shaft 2 of the engine 1. A cooling heat exchanger 5 is arranged in an air passage of the outside air 3 for cooling introduced by the fan 4.

The cooling heat exchanger 5 comprises a radiator 6 for cooling the cooling water of the engine 1 and an oil cooler 8 for cooling the working oil of a pump 7 driven by the engine 1. The radiator 6 is located on the leeward side. In addition, an oil cooler 8 is arranged on the windward side.

Further, an evaporator (evaporator) 21 of a refrigeration cycle is arranged on the windward side of the oil cooler 8.
The leeward side of the radiator 6, that is, the radiator 6 and the fan 4
A condenser (condenser) 22 for the refrigeration cycle is disposed between the refrigeration cycle and a compressor (compressor) 23 for the refrigeration cycle is disposed integrally with the engine 1. The evaporator 21, the condenser 22 and the compressor 23 And a cooler unit.

The evaporator 21, which forms a refrigeration cycle,
The condenser 22 and the compressor 23 are connected by a pipe 24, and the inside thereof is filled with a refrigerant 25. The drive shaft of the compressor 23 is connected to the crankshaft of the engine 1 via rotation transmission means 26 such as a pulley and an endless belt, and is driven by the engine 1.

The pump 7 attached to the engine 1
The hydraulic circuit of the hydraulic oil that is discharged and finally returned to the tank via the oil cooler 8 is the same as the conventional example shown in FIG.

Next, the operation of the embodiment shown in FIG. 1 will be described.

When the engine 1 is started, the fan 4 rotates to draw in the outside air 3 for cooling, and the flow of the outside air 3 for cooling is generated. The outside air 3 for cooling first hits the evaporator 21 of the refrigeration cycle, further hits the oil cooler 8 and the radiator 6 as the heat exchanger 5 for cooling, further hits the condenser 22 of the refrigeration cycle arranged on the leeward side, and finally To
The engine 1 is cooled and discharged to the outside.

In the refrigeration cycle, the refrigerant 25 compressed by the compressor 23 driven by the engine 1
The temperature rises to about 50 ° C. and is cooled by the condenser 22.
The cooled refrigerant 25 has a low temperature of, for example, about 10 ° C. in the evaporator 21 and cools the cooling external air 3. The refrigerant 25 that has cooled the outside air 3 returns to the compressor 23.

On the other hand, the outside air 3 for cooling, for example, at about 30 ° C., is cooled by the evaporator 21 and
The temperature becomes as low as about ° C. The cooling outside air 3 cooled by the evaporator 21 and cooled to a low temperature passes through the oil cooler 8 and the radiator 6 to efficiently cool the working oil and the engine cooling water to a high temperature of about 90 ° C., for example. . The cooling outside air 3 that has cooled the working oil and the cooling water further cools the condenser 22, becomes high in temperature, for example, about 140 ° C., and is discharged from the fan 4.

As described above, in the conventional cooling device, about 90 ° C.
The temperature of the discharged outside air, which had stopped, could be raised to about 140 ° C., and the amount of heat that could be removed increased accordingly.

As a result, when the outside air temperature is, for example, 40
Even if the temperature becomes as high as 50 ° C. or 50 ° C., the amount of heat that can be taken is not extremely reduced, and overheating can be prevented.

In other words, the condenser 22 of the refrigeration cycle arranged on the lee side of the cooling heat exchanger 5 is reduced by the temperature of the outside air by the evaporator 21 of the refrigeration cycle arranged on the lee side of the cooling heat exchanger 5. The temperature difference between the leeward and leeward sides of the cooling heat exchanger 5 is large, and the cooling heat exchanger 5 is cooled by the low-temperature cooling outside air 3.
Can be efficiently cooled, and overheating can be effectively prevented.

As described above, since the cooling efficiency is improved, the entire cooling device can be formed compact, and the space efficiency can be improved. In addition, since the cooling efficiency is improved, the number of revolutions of the fan 4 is reduced, and the flow rate of the outside air is reduced, so that the noise can be reduced. can do.

Next, with reference to FIG. 2, a cooling device which is maintenance-free will be described. The same parts as those shown in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

The fan 4 rotated by the engine 1 is covered by a hood cover 32 together with the radiator 6 having the heat dissipating fins 31, the oil cooler 8 and the evaporator 21. The fan 4 is provided with an opening 33 of the hood cover 32.
Are located in

In the hood cover 32, a large diameter portion 34 covering the fan 4, the radiator 6 and the oil cooler 8 and a small diameter portion 35 covering the evaporator 21 are continuously connected by an inclined portion 36, and further upstream of the evaporator 21. It has a suction port 37 on the side.

An air cleaner 39 for purifying the outside air for cooling is provided to an inlet 37 of the hood cover 32 by an air duct 38.
Is connected. The air cleaner 39 removes dust in the outside air by a filter provided inside, and supplies the dust to the air duct 38.

In the embodiment shown in FIG. 1, a condenser 22 is arranged between the radiator 6 and the fan 4,
The condenser 22 is cooled by the outside air for cooling the radiator 6.
In the embodiment shown in FIG. 2, the condenser 22 is disposed outside the hood cover 32, and the fan 4 rotated by the engine 1 is provided.
A separate sub-fan 42 rotated by an electric motor 41
This cools the condenser 22.

That is, the condenser 22 of the refrigeration cycle is disposed outside the hood cover 32, and a sub-fan 42, which is rotated by an electric motor 41 as a driving means different from the engine 1, is provided opposite to the condenser 22. Have been. The electric motor 41 is driven by electric power supplied from a vehicle-mounted battery (not shown) or a generator (not shown) driven by the engine 1 like the compressor 23.

Next, the operation of the embodiment shown in FIG. 2 will be described.

The cooling outside air 3 sucked into the air cleaner 39 by the suction force of the fan 4 rotated by the engine 1
After being cleaned in the air cleaner 39, it is introduced into the hood cover 32 through the air duct 38 through the suction port 37 of the hood cover 32, cooled by the evaporator 21 to a low temperature, and then cooled by the oil cooler 8 and the radiator 6. , The working oil and the engine cooling water are efficiently cooled.

As described above, only the outside air purified by the air cleaner 39 is supplied to the evaporator 21, the oil cooler 8 and the radiator 6 in the hood cover 32, and the cooling by the clean outside air is performed. However, there is no risk of clogging with dust in the outside air.

Therefore, the cooling efficiency can be improved by using the fine heat radiation fins 31 and the necessity of maintenance of the heat radiation fins 31 can be reduced, so that maintenance free operation can be achieved.

Further, since outside air for cooling from the air cleaner 39 to the fan 4 passes through the inside of the air duct 38 and the hood cover 32, noise generated when passing through the evaporator 21, the oil cooler 8 and the radiator 6 leaks to the outside. The noise generated from the fan 4 due to the rectifying action of the hood cover 32 can be reduced.

Further, since the condenser 22 of the refrigeration cycle disposed outside the hood cover 32 is cooled by the sub-fan 42 rotated by the electric motor 41, the engine 1
The cooling of the condenser 22 can be stably performed by an appropriate amount of cooling air that is not affected by the number of rotations.

The present invention is suitable for a construction machine such as a hydraulic shovel, a bulldozer, a loader or the like, which drives a pump 7 of a hydraulic circuit by the engine 1, but is also applicable to a hydraulic circuit driven engine other than the construction machine. It goes without saying that the present invention can be applied, and furthermore, it can be used as a cooling device for cooling an engine of a general vehicle not provided with a hydraulic circuit.

[0052]

According to the first aspect of the present invention, the outside air is cooled by the evaporator of the refrigeration cycle arranged on the windward side of the cooling heat exchanger, and the cooling heat exchanger is efficiently cooled by the outside air. Therefore, a sufficient cooling effect can be obtained even when the outside air temperature is high, and overheating can be effectively prevented. In addition, since the cooling effect has been improved, the entire cooling device can be made compact, space efficiency can be improved, and since there is no need to increase the air volume, the number of rotations of the fan can be reduced to reduce the introduction flow rate of outside air, thereby reducing noise. And the like.

According to the second aspect of the present invention, the condenser of the refrigeration cycle arranged on the lee side of the cooling heat exchanger can be cooled by the external cooling air generated by the fan of the engine, and the condensation action of the condenser is secured. It is not necessary to provide a special cooling means for cooling, so that the cooling device can be made compact.

According to the third aspect of the present invention, since the compressor of the refrigeration cycle is driven by the engine, there is no need to provide a dedicated compressor driving means, and the cooling device can be made compact.

According to the present invention, the engine cooling water of the radiator and the hydraulic oil of the oil cooler can be simultaneously cooled by the common cooling air generated by the fan of the engine, and the overheating of the cooling water and the hydraulic oil can be reduced. It can be effectively prevented.

According to the fifth aspect of the present invention, the cooling heat exchanger having the radiating fins and the evaporator are covered with the hood cover, and the air cleaner is connected to the suction port of the hood cover. Only the outside air is supplied to the evaporator and cooling heat exchanger in the hood cover, and cooling is performed by clean outside air.Therefore, there is no risk of the heat radiation fins being clogged with dust in the outside air, and fine heat radiation The cooling efficiency can be improved by using the fins, and the necessity of maintenance of the radiating fins can be reduced, so that maintenance-free operation can be achieved.

According to the sixth aspect of the present invention, since the outside air for cooling from the air cleaner to the fan passes through the inside of the air duct and the hood cover, noise generated when passing through the evaporator or the heat exchanger for cooling is reduced. And the noise generated from the fan due to the rectifying action of the hood cover can be reduced.

According to the seventh aspect of the present invention, the condenser of the refrigeration cycle disposed outside the hood cover is cooled by the sub-fan rotated by driving means different from the engine. Cooling of the condenser can be stably performed by an appropriate amount of cooling air that is not performed.

[Brief description of the drawings]

FIG. 1 is a layout diagram showing an embodiment of a cooling device according to the present invention.

FIG. 2 is a layout view showing another embodiment of the cooling device according to the present invention.

FIG. 3 is a layout view showing a conventional cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 3 Cooling outside air 4 Fan 5 Cooling heat exchanger 6 Radiator 7 Pump 8 Oil cooler 21 Evaporator 22 Condenser 23 Compressor 31 Radiation fin 32 Food cover 37 Suction port 38 Air duct 39 Air cleaner 41 As a driving means different from the engine Electric motor 42 sub fan

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tomomi Inoue 7-14, Wadamiya-dori, Hyogo-ku, Kobe City, Hyogo Prefecture Inside Seiryo Engineering Co., Ltd. (56) References JP-A-63-170520 (JP, A) 63-102913 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F01P 3/22 F01P 11/08 F01P 11/10 F02D 29/04 F25D 17/08 302

Claims (7)

(57) [Claims] 1. A fan which is rotated by an engine and introduces outside air for cooling toward the engine, a cooling heat exchanger arranged in an air passage of the outside air for cooling introduced by the fan, and a heat for cooling. A cooling device comprising: a refrigerating cycle evaporator disposed on the windward side of the exchanger. 2. The cooling device according to claim 1, further comprising a refrigeration cycle condenser disposed downstream of the cooling heat exchanger. 3. The cooling device according to claim 1, further comprising a compressor of a refrigeration cycle driven by an engine. 4. The cooling heat exchanger according to claim 1, further comprising: a radiator for cooling engine cooling water; and an oil cooler for cooling hydraulic oil of a pump driven by the engine. The cooling device according to any one of the above. 5. A hood cover that covers a cooling heat exchanger having heat-dissipating fins and an evaporator and has a suction port upstream of the evaporator, and an air cleaner that is connected to the suction port of the hood cover and purifies outside air for cooling. The cooling device according to any one of claims 1, 3 and 4, further comprising: 6. The cooling device according to claim 5, wherein the air cleaner and the suction port of the hood cover are connected by an air duct, and the fan is covered by the hood cover together with the evaporator and the cooling heat exchanger. 7. A refrigeration cycle condenser disposed outside the hood cover, and a sub-fan provided opposite to the condenser and rotated by a driving means different from the engine is provided. 7. The cooling device according to 5 or 6.