JPS59192614A - Cooling device for vehicle - Google Patents

Abstract

PURPOSE:To completely prevent formation of frost on an evaporator during rotation at a low speed of an auxiliary engine, by a method wherein, plural electric motor-driven fans are used as a blast fan to maintain a blast amount at a constant value during rotation both at a high speed and at a low speed of the auxiliary engine. CONSTITUTION:A cooling device for vehicle is constituted such that an suxiliary engine 1, acting as a driving source, a compressor 3, a condenser 4, a liquid receiver 7, an evaporator 8, and blast fans 11, 11' are mounted on a single frame 13 to form a refrigerant unit which is placed on a vehicle. In such a cooling device, electric motors 12 and 12' independently driving the blast fans 11 and 11' in rotation respectively, are mounted, so that a specified blast amount can be fed with the aid of the electric motor-driven fans 11, and 11' irrespective of the number of revolutions of the auxiliary engine 1. This enables to perfectly prevent formation of frost on an evaporator during rotation at a low speed of the auxiliary engine, and permits improvement in cooling capacity during rotation at a high speed of the engine and reduction of noise.

Description

[Detailed description of the invention] The present invention relates to a cooling device for a vehicle.

Cooling equipment such as a compressor, condenser, liquid receiver, evaporator, and blower fan powered by an auxiliary engine are mounted on the frame to form an integrated cooler unit, and this unit is mounted under the floor of the bus. Vehicle cooling systems that cool the interior of a vehicle are already widely used.

Conventionally, in this type of cooling device, an auxiliary engine, a compressor, and a blower fan are connected directly or through a power transmission mechanism such as a V-belt, and the compressor and the blower fan are rotationally driven by the auxiliary engine.

However, although the amount of air blown changes in proportion to the rotational speed of the blower fan, the cooling capacity is not proportional to the rotational speed of the compressor, resulting in a characteristic as shown by the thick line Q in FIG.

For this reason, the cooling capacity per unit airflow rate increases as the rotation speed decreases, and the amount of temperature drop due to air cooling also increases as the speed decreases. Therefore, there is a drawback that the evaporator outlet air temperature becomes too low and problems such as the storage box are likely to occur.

The present invention aims to eliminate the above-mentioned conventional drawbacks and provide a cooling device that is highly effective, particularly in the low engine speed range where the engine is highly usable.

Generally speaking, in a conventional vehicle cooling system using an auxiliary engine as a power source, in which the blower fan is rotationally driven by the auxiliary engine, the auxiliary engine has a high When rotating (engine speed n
2) If the airflow characteristic W1 is set to exceed the airflow ID of the blower fan that matches the cooling capacity at that time, the airflow rate of the blower fan will be proportional to the rotation speed, so the auxiliary engine's low The air flow rate for the cooling capacity α during rotation (engine speed rL1) is approximately 0.75 of the required air flow rate as shown in C.
As a result, the cooling capacity per unit air flow increases,
As mentioned earlier, the temperature drop end due to cooling becomes large, and the problem of frost formation on the evaporator is likely to occur.

According to the experimental results, when B2 is 1800 A, the air flow is 5000
#pflr had a temperature difference of about 14°C, but rL
When I is 1000fp-, the ventilation fk is 1670m)'Hr
Therefore, the temperature difference is about 19 to 20℃, which means that the artificial air temperature of the evaporator, that is, the indoor air temperature.
When the temperature reaches 24-25℃, the auxiliary engine is turned to low speed tL1.
In this case, the temperature of the outlet air of the evaporator will be 4 to 5°C, and the temperature of the refrigerant flowing in the evaporator will reach -3 to -6°C, and frost will begin to form.

On the other hand, if the airflow characteristic W2 is set to obtain an appropriate airflow amount C' at low speeds of the auxiliary engine, that is, at rLl, the airflow rate may become too large, such as airflow ld' at high speeds, that is, at rLl. Not only does the cooling capacity per unit amount of air flow become too small, but the power of the blower fan increases in proportion to the sixth power of the rotation speed, which increases power consumption and fuel consumption, and shortens the life of the blower fan. Furthermore, the noise inside the mold increases significantly due to the increase in the number of rotations of the blower fan.
It causes many problems.

In the present invention, as shown in FIG. 1.2, an auxiliary engine 1 is mounted on a frame 13, and the auxiliary engine 1 compresses 8!
The condenser 4.3 is configured to rotate and drive the condenser 4.3 on the frame 13. In a vehicle cooling system in which a radiator 51, liquid receiver 7, and evaporator 8 are installed, a case 9, etc. are attached to form an integrated cooling unit, which is installed under the floor of a bus. Two or more than two blower fans are installed in parallel as indicated by reference numerals 11 and 11', and the plurality of blower fans 11. ．． 11
An electric motor 12 that independently rotates the
, 12', etc., and the plurality of electric motor fans 11.1
1' etc., it is possible to blow a constant amount of air regardless of the rotational speed of the auxiliary engine.

The 'electric motor 12.12' is driven by an on-vehicle power source.

In Figures 1 and 2, 2 indicates the condenser 4 and the radiator (
This is for cooling the cooling water of auxiliary engine 1)
5 is a cooling fan for cooling 6 is a fan guide, 10
1 is a guide air intake port of the case 9, and 11α and 11d are blow-off ports of the blower fans 11 and 1Y, which are respectively connected to a blow-off duct (not shown) on the vehicle body side. Reference numeral 14 denotes a mounting portion for attaching the frame 13 to the vehicle body side with bolts or the like, and the auxiliary engine 1 and the pressure &1tlA3 are supported on the frame 13 in a vibration-proof manner via an elastic material 15 such as rubber.

As described above, a plurality of electric motor fans 11. According to the trap of the present invention using it', the amount of air blown can be kept constant regardless of changes in the rotational speed of the auxiliary engine 1, so the amount of air blown can be kept constant regardless of changes in the rotation speed of the auxiliary engine 1. The air flow rate can be set at point C' that matches the cooling capacity at that time, and in some cases, the air flow rate of Wl# can be set to a long value such as I, so that the cooling capacity per unit air flow rate can be adjusted to an appropriate level. This makes it possible to completely prevent frost formation on the evaporator 8, which was a drawback of conventional devices.

As mentioned above, if the air flow rate of the electric motor fans 11 and 11' is set to 0, for example, to prevent frost formation in the low speed rotation range of the auxiliary engine 1, then in the high speed rotation range 1'L2 of the auxiliary engine 1, As shown in "d", the amount of air blown is small relative to the cooling capacity, but when the auxiliary engine 1 is operated at high speed, the indoor temperature generally decreases rapidly, such as when the outside air temperature is 60°C or higher and the indoor temperature has risen significantly due to solar radiation, etc. It is used when the room temperature needs to be lowered, and the auxiliary engine 1 is switched to low speed rotation when the room temperature drops to about 28 to 50'C, so naturally the artificial air temperature of the evaporator is high, so the cooling capacity per unit air flow is low. Even if the air temperature increases, the evaporator outlet air temperature will not drop to the freezing point, so there is no need to worry about it at all.In fact, if the cooling capacity per unit air flow increases, the indoor temperature can be lowered more quickly. This is preferable for the purpose of reducing indoor noise, and is also preferable from the perspective of reducing indoor noise.

In the above, by using two electric motor fans or a plurality of two or more electric motor fans, it is possible to significantly reduce power consumption.

In other words, for example, if one fan is designed to produce an air flow of 6oooom)ir at a rotation speed of 180Or-, approximately 5 PS of power is required, but at a rotation speed of 900Or-, the airflow amount is is 3000 x request=
1500 m'/Hr, and the power is proportional to the 6th power of the rotation speed, so 5FSX (surface) = 5FSX0.125)
=0.625PS.

Therefore, if two fans with a rotation speed of 90 Orpm are used,
0.625X2=1500X2= with 1.25PS power
It is theoretically possible to blow Ir at 5,000 rl/l, but in reality it is 2,400 to 260 rl/l due to increased resistance of the duct, etc.
0? ? Air is blown at i/Hr. However, one fan blows 2400 m'/I (the power required to blow air is 5 PS).
× (Dish = 2.56 PS, which requires about twice the power of 1.25 PS in the case of 7772 (fixed 000). By providing a plurality of them, it is possible to significantly reduce power consumption compared to the conventional one.

In the above embodiment, the power for the electric motors 12, 12' is taken from the on-vehicle power supply, but a generator driven by the auxiliary engine 1 is mounted on the frame 13, and this generator is powered by an electric power source. It may also be used as a power source for the motor 12°12'.

Further, each of the plurality of electric motor fans can be individually opened 1 in the driver's seat portion, thereby controlling the amount of air blown.

As described above, according to the present invention, in an auxiliary engine-driven integrated cooling device for a vehicle that is mounted on a frame using an auxiliary engine as a power source and mounted under the floor of a vehicle as an integrated unit, two Alternatively, by adopting a configuration in which multiple electric motor quans of 2@ or more are installed in parallel with the evaporator, the amount of air blown can be kept constant both when the auxiliary engine is at high speed and at low speed, and when the auxiliary engine is at low speed. It is possible to completely prevent the problem of the evaporator landing side at times, improve the cooling capacity and reduce noise when the auxiliary engine rotates at high speeds, and also significantly reduce power consumption. , by simply installing a heater core in addition to the evaporator, it can blow air for heating, and it can also blow air for ventilation when air conditioning is not in use, which brings great practical effects. It's something you get.

[Brief explanation of the drawing]

1 and 2 are a plan view and a front view showing an embodiment of the present invention, and FIG. 3 is a diagram showing the relationship between cooling capacity and air flow rate. 1... Auxiliary engine, 3... Compressor, 4... Condenser, T... Receiver, 8... Evaporator, 9... Case, 11゜1 (... Air blower Fan, 12.12'... electric motor, 13... frame.

Claims (1)

[Claims] An auxiliary engine is used as a drive source, and the auxiliary engine, compressor, condenser, liquid receiver, evaporator, blower fan, etc. are mounted on one claim to form a cooling unit, which is mounted on a vehicle. A vehicle cooling device characterized in that a plurality of electric motor fans of 2 lil or two or more are used as a blower fan.