JP2007076504A - Vehicle air conditioner and its air blowing control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle air conditioner and its air blowing control device capable of eliminating the necessity of a vehicle test etc. and suppressing unbalance of right and left air quantity at the time of motor lock. <P>SOLUTION: This vehicle air conditioner is provided with one first electric motor M3 and one second electric motor M4 sending air to one heat sink and the other first and second electric motors M7, M8 sending air to the other heat sink. One and the other first electric motors M3, M7 and one and the other the second electric motors M4, M8 are arranged in parallel with a power supply 25, respectively. First connection parts AR4, AR13, AR14 switching connection of one and the other first electric motors M3, M7 and one and the other second electric motors M4, M8 so as to connect them with the power supply 25 in series or in parallel are provided. In the maximum air blowing mode, one and the other first electric motors M3, M7 and one and the other second electric motors M4, M8 are connected in parallel, and in the minimum air blowing mode, they are connected in series. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an air conditioner for a vehicle used for air conditioning of a vehicle, in particular, air conditioning of a bus, and an air blow control device thereof.

Conventionally, a vehicle air conditioner used for a bus is different from a general passenger car air conditioner in that it includes a plurality of blower fans that allow indoor air to pass through an evaporator and a plurality of electric motors that rotationally drive each blower fan. Is provided.
In the vehicle air conditioner used for the bus described above, the power supplied to the electric motor is controlled by switching the connection of the circuit for supplying power to the plurality of electric motors in series or in parallel, and the air is blown from the blower fan. A method of controlling the amount of air flow is generally known (for example, see Patent Document 1).
JP 2004-338486 A (page 4-6, FIG. 1, FIG. 2, etc.)

In the above-mentioned Patent Document 1, there is a vehicle air blow control device that includes a plurality of first electric motors that respectively drive a plurality of first air blow fans and that can control each of the first electric motors. A vehicle air blow control device having a plurality of second electric motors that respectively drive two air blow fans and connection control means for connecting the second electric motors in series or in parallel is disclosed.
According to the above-described vehicle air blow control device, the air flow rate can be changed while suppressing an increase in the number of relay switches and registers by connecting the second electric motor in series or in parallel.

However, in the vehicle air blow control device disclosed in Patent Document 1 described above, the minimum mode (Lo mode) for reducing the air flow amount to the minimum value, the first intermediate mode for setting the intermediate value, and the second intermediate mode ( In the (Me1 mode, Me2 mode), the power supplied to the first electric motor is adjusted using a resistor (resistive element).
Since this register is a heating element, there has been a problem that the register temperature changes and its characteristics change when the airflow hitting the register changes.
Specifically, the amount of air hitting the register is influenced by the fan arrangement direction, the register arrangement position, the shape of the duct for guiding the air blown by the first and second fans, and the like. For this reason, it has been necessary to conduct a vehicle test or the like in advance to check whether the register arrangement position is appropriate.

Moreover, in the vehicle air blow control device disclosed in Patent Document 1 described above, the first electric motor and the second electric motor are arranged in a row in the front-rear direction on the right side and the left side of the bus. The first electric motors arranged in a row on the right or left side of the bus form a pair with other first electric motors in the same row, and the pair of first electric motors are switched in series or in parallel with the power source. Was connected.
In such a configuration, for example, when the pair of first electric motors are connected in parallel and one of the first electric motors is locked, most of the current flows through the locked first electric motor. The current hardly flows to the other first electric motor. Therefore, the other unlocked first electric motor hardly rotates, and there is a problem that both of the pair of first electric motors do not rotate.

Thus, when two of the first electric motors arranged on the right or left side of the bus are stopped simultaneously, an unbalance of the air volume blown from the left and right occurs. In such a case, when the vehicle air conditioner is operated in the vicinity of the frost condition, there is a problem that the evaporator on the side where the first electric motor is stopped frosts (freezes).
In order to solve this problem, a method of arranging sensors for detecting frost on the evaporators on both sides is known. However, it is necessary to arrange the sensors, and there is a problem that the manufacturing cost increases.

  The present invention has been made to solve the above-described problems, and eliminates the need for a vehicle test or the like, and can suppress the left and right air volume unbalance when the motor is locked and the air blower for the vehicle. An object is to provide a control device.

In order to achieve the above object, the present invention provides the following means.
The vehicle air conditioner of the present invention includes a compressor that compresses a refrigerant, a radiator that dissipates the heat of the compressed refrigerant, a decompressor that depressurizes the pressure of the dissipated refrigerant, and heats the reduced refrigerant. An air conditioner for a vehicle having at least two heat absorbers for absorbing air, wherein one first electric motor that drives one blower fan to blow air to one heat absorber and one first Two electric motors, and the other first electric motor and the other second electric motor for driving the other blower fan to blow air to the other heat absorber. And the other first electric motor is arranged in parallel with the power source, the one second electric motor and the other second electric motor are arranged in parallel with the power source, and the one and the other A first electric motor of A first connection portion is provided for switching and connecting the one and the other second electric motors in series or in parallel with the power source. In the maximum blowing mode, the one and the other first electric motors and the one And the other second electric motor are connected in parallel to the power source by the first connecting portion, and in the minimum air blowing mode, the one and the other first electric motors and the one and the other second electric motors. An electric motor is connected to the power supply in series by the first connection portion.

  According to the present invention, one and the other first electric motor and the one and the other second electric motor are connected in parallel to the power source in the maximum blowing mode by the first connecting portion, and in the minimum blowing mode. Since it is connected in series with the power supply, the air volume can be controlled without using a resistor affected by heat. Therefore, the vehicle air conditioner can exhibit predetermined performance without performing a vehicle test or the like as in a vehicle air conditioner using a register.

That is, when one and the other first electric motors and one and the other second electric motors are connected in parallel to the power source, the one and the other first electric motors, the one and the other second electric motors. Since the voltage of the power source is applied to each of the electric motors, the one and the other first electric motors and the one and the other second electric motors are driven at the rated rotational speed, and the maximum blowing mode can be realized.
On the other hand, when one and the other first electric motors and one and the other second electric motors are connected in series to the power source, one and the other first electric motors, one and the other second electric motors. Since a voltage lower than the voltage of the power supply is applied to each of the electric motors, one and the other first electric motor and the one and the other second electric motor are driven at a rotational speed lower than the rated rotational speed, and the minimum air blowing mode is set. realizable.
Therefore, the air volume can be controlled without using a register affected by heat.

For example, when one first electric motor is locked, one first electric motor and the other first electric motor are connected in parallel, so one first electric motor is connected to the first electric motor pair. Most of the flowing current flows, and the remaining current flowing through the first electric motor pair flows through the other first electric motor. That is, when one of the first electric motors is locked, the current flowing through the other first electric motor is reduced, so that the other first electric motor hardly rotates.
Therefore, the one blower fan and the other blower fan that are driven by the first electric motor and the other first electric motor do not rotate, and the flow rate of air blown to one heat absorber and the other heat absorber decreases. That is, even when one of the first electric motors is locked, it is possible to prevent an unbalance in the flow rate of air blown to one heat absorber and the other heat absorber.
The same applies when the other first electric motor of the first electric motor pair is locked, and the same applies when one or the second electric motor of the second electric motor pair is locked.

In the above invention, the compressor, the radiator, the decompressor, and the one and the other heat absorbers are connected to one refrigerant circuit, and the endothermic component is connected to at least one of the one heat absorbers. It is desirable that a temperature detector for measuring the temperature of the vessel is provided.
According to the present invention, since one and the other heat absorbers are connected to one refrigerant circuit, and the air flow rates in the one and the other heat absorbers are always substantially the same, the temperature conditions of these heat absorbers are substantially the same. It becomes. Therefore, by providing a temperature detection unit that measures the temperature of the heat absorber in at least one of the heat absorbers, it is possible to estimate all the temperatures of the one and the other heat absorbers.
For example, when a frost sensor of a heat absorber is used as the temperature detector, frost in one and the other heat absorbers can be detected by disposing the frost sensor in one of the heat absorbers. In addition, even if one of the one and the other first electric motors and one of the one and the other second electric motors are locked, the air flow rate in the one and the other heat absorbers is substantially the same, so The frost of the other heat absorber can be detected.

  In the above invention, when the one and the other first electric motors and the one and the other second electric motors are connected in series, the one and the other first electric motors and the one and the other ones It is desirable that a limiting unit for limiting current is provided between the second electric motor.

  According to the present invention, when one and the other first electric motors and the one and the other second electric motors are connected in series, the one and the other first electric motors and the one and the other second electric motors. A limiting portion is arranged between the electric motor. Therefore, when one and the other first electric motor and the one and the other second electric motor are connected in series, one of the first electric motor, the other first electric motor, and the one second electric motor. Even if any one of the other second electric motors is locked, the current is limited by the limiting unit, and one first electric motor, the other first electric motor, one second electric motor, The temperature increase of the other second electric motor can be prevented.

  In the above invention, one third electric motor that drives one blower fan to blow air to one heat absorber and the other blower fan to blow air to the other heat absorber. The other third electric motor, the one third electric motor, and the second connection portion for switching and connecting the other third electric motor in series or in parallel to the power source, In the maximum blowing mode, the one third electric motor and the other third electric motor are connected in parallel to the power source by the first connecting portion, and in the minimum blowing mode, the one first electric motor It is desirable that the three electric motors and the other third electric motor are connected in series to the power supply by the third connecting portion.

  According to the present invention, one third electric motor and the other third electric motor are connected in parallel to the power source in the maximum air blowing mode by the second connecting portion, and in series with the power source in the minimum air blowing mode. Therefore, the air volume can be controlled without using a resistor that is affected by heat. Therefore, the vehicle air conditioner can exhibit predetermined performance without performing a vehicle test or the like as in a vehicle air conditioner using a register.

That is, when one third electric motor and the other third electric motor pair are connected in parallel to the power source, the voltage of the power source is applied to each of the one and the other third electric motors. The one and the other third electric motors are driven at the rated rotational speed, and the maximum blowing mode can be realized.
On the other hand, when one and the other third electric motors are connected in series with the power source, a voltage lower than the voltage of the power source is applied to each of the one and the other third electric motors. The third electric motor is driven at a rotational speed lower than the rated rotational speed, and can realize the minimum ventilation mode.
Therefore, the air volume can be controlled without using a register affected by heat.

  In the above invention, when the one third electric motor and the other third electric motor are connected in series, between the one third electric motor and the other third electric motor, It is desirable that a limiting unit for limiting the current is provided.

  According to the present invention, when one third electric motor and the other third electric motor are connected in series, the limiting unit is provided between the one third electric motor and the other third electric motor. Has been placed. Therefore, when one third electric motor and the other third electric motor are connected in series, even if one of the other electric motors is locked, the current is limited by the limiting unit. It is limited, and the temperature rise of one and the other third electric motors can be prevented.

  The air blow control device for a vehicle air conditioner according to the present invention drives one blower fan to blow air to one heat absorber, one first electric motor and one second electric motor, and the other blower. The other first electric motor and the other second electric motor, which drive the fan to blow air to the other heat absorber, and the one first electric motor and the other first electric motor Are arranged in parallel to the power source, the one second electric motor and the other second electric motor are arranged in parallel to the power source, the one and the other first electric motors, A first connection portion is provided for switching and connecting the one and the other second electric motors in series or in parallel to the power source. In the maximum blowing mode, the one and the other first electric motors and the one and the other A second electric motor is connected in parallel to the power source by the first connecting portion, and in the minimum air blowing mode, the one and the other first electric motors and the one and the other second electric motors are The first connection portion is connected in series to the power source, and the one and the other first electric motors and the one and the other second electric motors are connected in series. And the limiting part which restrict | limits an electric current is provided between the other 1st electric motor and the said 1st and other 2nd electric motor, It is characterized by the above-mentioned.

  According to the present invention, one and the other first electric motor and the one and the other second electric motor are connected in parallel to the power source in the maximum blowing mode by the first connecting portion, and in the minimum blowing mode. Since it is connected in series with the power supply, the air volume can be controlled without using a resistor affected by heat. Therefore, the air blow control device for a vehicle air conditioner can exhibit a predetermined performance without performing a vehicle test or the like like the air blow control device for a vehicle air conditioner using a register.

For example, when one first electric motor is locked, one first electric motor and the other first electric motor are connected in parallel, so one first electric motor is connected to the first electric motor pair. Most of the flowing current flows, and the remaining current flowing through the first electric motor pair flows through the other first electric motor. That is, when one of the first electric motors is locked, the current flowing through the other first electric motor is reduced, so that the other first electric motor hardly rotates.
Therefore, the one blower fan and the other blower fan driven by the one and the other first electric motors do not rotate, and the flow rate of air blown by the one and other blower fans is reduced. That is, even when one of the first electric motors is locked, it is possible to prevent an unbalance of the air flow rate blown by the one and the other blower fans.

  When one and the other first electric motor and one and the other second electric motor are connected in series, between the one and the other first electric motor and the one and the other second electric motor A limiting part is arranged. Therefore, when one and the other first electric motor and the one and the other second electric motor are connected in series, one of the first electric motor, the other first electric motor, and the one second electric motor. Even if any one of the other second electric motors is locked, the current is limited by the limiting unit, and one first electric motor, the other first electric motor, one second electric motor, The temperature increase of the other second electric motor can be prevented.

  According to the air blow control device for a vehicle air conditioner of the present invention, the first connecting portion causes the one and the other first electric motors and the one and the other second electric motors to be connected to the power supply in the maximum air blowing mode. Since they are connected in parallel and connected in series to the power supply in the minimum air blowing mode, the air volume can be controlled without using a register affected by heat. Therefore, the vehicle air conditioner can exhibit a predetermined performance without performing a vehicle test or the like as in a vehicle air conditioner using a register.

  Since one and the other first electric motor are connected in parallel and one and the other second electric motor are connected in parallel, either one of the one or the other first electric motor or one and the other Even if one of the second electric motors is locked, both the one and the other first electric motors or both the one and the other second electric motors are stopped. There is an effect that it can be suppressed.

A bus air conditioner according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6.
FIG. 1 is a schematic diagram illustrating the overall configuration of a bus air conditioner according to the present embodiment. FIG. 2 is a circuit diagram illustrating a circuit configuration of the bus air conditioner of FIG.

As shown in FIGS. 1 and 2, the bus air conditioner (vehicle air conditioner) 1 releases two compressors 3 and 3 for compressing the refrigerant and the heat of the compressed refrigerant to the outside air. A condenser unit 7 having a condenser (heat radiator) 5, an expansion valve (decompressor) 9 for reducing the pressure of the refrigerant that has released heat, and an evaporator (heat absorber, one of which the depressurized refrigerant takes heat of the air in the bus) , The other heat absorber 11) and two evaporator units 13R and 13L.
The compressors 3, 3, the condenser 5, the expansion valves 9, 9, and the evaporators 11, 11 are connected by a single system refrigerant circulation channel 15. The compressors 3 and 3, the expansion valves 9 and 9, and the evaporators 11 and 11 are connected in parallel to the refrigerant circulation passage 15.

Compressors 3 and 3 are disposed at the rear of the bus B, and are driven to rotate by a driving source such as an engine.
On the roof in front of the bus B, the capacitor unit 7 is arranged, and the capacitor unit 7 is provided with a plurality of capacitor fans 17 for blowing outside air to the capacitor 5.

On the ceiling of the bus B, behind the capacitor unit 7, evaporator units 13R and 13L are arranged separately on the left and right. The evaporator unit 13 is provided with eight evaporator fans that are driven by an electric motor (described later) that blows air in the bus to the evaporator 11.
Specifically, evaporator fans B1, B2, B3, and B4 are sequentially arranged in a line from the front (right side in FIG. 2) to the rear (left side in FIG. 2) of bus B in right evaporator unit 13R. Yes. Similarly, evaporator fans B5, B6, B7, and B8 are arranged in a row in the left evaporator unit 13L.

FIG. 3 is a circuit diagram for explaining an evaporator fan control circuit in the bus air conditioner of FIG.
As shown in FIG. 3, the control circuit (fan control device) 19 controls a first control circuit 21 that controls the evaporator fans B1, B2, B5, and B6 (see FIG. 2) disposed in front of the evaporator units 13R and 13L. Power to the second control circuit 23 that controls the evaporator fans B3, B4, B7, and B8 (see FIG. 2) disposed in front of the evaporator units 13R and 13L, and the first control circuit 21 and the second control circuit 23. And a battery (power source) 25 for supplying the power.

  The first control circuit 21 includes electric motors (one third electric motor) M1 and M2 for rotating the evaporator fans B1, B2, B5 and B6, respectively, and electric motors (the other third electric motor) M5 and M6. And relay switches AR1, AR2, relay switches (second connection parts) AR5, AR6, AR11, AR12, fuses F1, F2, F5, F6, and fuses (limitation parts) F11, F12. ing.

Here, the electric motors M1, M2, M5, and M6 are motors having the same capacity. For example, step motors can be used. The fuses F1, F2, F5, and F6 have the same fusing characteristics. For example, a blade fuse can be exemplified. The fuses F11 and F12 have the same fusing characteristics and have a fusing characteristic lower than those of the fuses F1, F2, F5, and F6. As these fuses F1, F2, F5, F6, F11, and F12, for example, blade fuses can be used.

The relay switch AR1 is connected in series between the battery 25 and the electric motor M1, and a fuse F1 is disposed between the relay switch AR1 and the battery 25. A relay switch AR11 is connected in series between the electric motor M1 and the ground G.
The relay switch AR5 is connected in series between the battery 25 and the electric motor M5, and a fuse F5 is disposed between the relay switch AR5 and the battery 25. The electric motor M5 is connected to the ground G. A wiring extending from the relay switch AR11 is connected between the relay switch AR5 and the electric motor 5, and a fuse F11 is connected in series to the wiring.

Relay switch AR2 is connected in series between battery 25 and electric motor M2, and fuse F2 is connected in series between relay switch AR2 and battery 25. The electric motor M2 is connected to the ground G.
The relay switch AR6 is connected in series between the battery 25 and the electric motor M6, and a fuse F6 is connected in series between the relay switch AR6 and the battery 25. A relay switch AR12 is connected in series between the electric motor M6 and the ground G. A wiring extending from the relay switch AR12 is connected between the relay switch AR2 and the electric motor M2, and a fuse F12 is connected in series to the wiring.

  The second control circuit 23 includes an electric motor (one first electric motor) M3, an electric motor (the other first electric motor) M7, and an electric motor that rotationally drives the evaporator fans B3, B4, B7, and B8. (One second electric motor) M4, electric motor (the other second electric motor) M8, relay switch AR3, relay switches (first connection portions) AR4, AR13, AR14, fuses F3, F4, And a fuse (restriction unit) F13.

Here, the electric motors M3, M4, M7, and M8 are motors having the same capacity, and for example, step motors can be used.
The fuses F3 and F4 have the same fusing characteristics. For example, a blade fuse can be exemplified. The fuse F13 has a low fusing characteristic as compared with the fuses F3 and F4. As these fuses F3, F4, and F13, for example, blade fuses can be used.

The electric motors M3 and M7 are connected in parallel to the battery 25, and the relay switch AR3 is connected in series between the electric motors M3 and M7 and the battery 25. A relay switch AR13 is connected in series between the electric motor M3 and the ground G, and a relay switch AR14 is connected in series between the electric motor M7 and the ground G.
The electric motors M8 and M4 are connected in parallel to the battery 25, and the relay switch AR24 is connected in series between the electric motors M3 and M8 and the battery 25. The electric motors M3 and M8 are connected to the ground G.
The wiring branched from between the relay switch AR4 and the electric motors M3 and M8 is divided into two on the way and connected to the relay switches AR13 and AR14, and a fuse F13 is connected to the wiring in series.

Next, the operation of the vehicle air conditioner having the above configuration will be described.
First, the refrigerant flow in the bus air conditioner 1 will be described with reference to FIGS. 1 and 2.
As shown in FIGS. 1 and 2, the refrigerant is compressed by the compressors 3 and 3, and is sent out toward the condenser 5. The compressed refrigerant flows into the condenser 5, releases heat to the air outside the bus B, and condenses and liquefies. Air outside the bus B is passed through the condenser 5 by the condenser fan 17.

The liquefied refrigerant is decompressed by the expansion valves 9 of the evaporator units 13R and 13L and flows into the evaporator 11. The refrigerant flowing into the evaporator 11 takes heat from the air in the bus B and evaporates and vaporizes. Air in the bus B is passed through the evaporator 11 by an evaporator fan described later. The vaporized refrigerant is sucked into the compressors 3 and 3, compressed again, and sent out toward the condenser 5.
Hereinafter, the refrigerant is circulated by repeating the above-described cycle, and the bus air conditioner 1 cools the air in the bus B.

なお、上記の表において、ＨｉはＨｉモードを意味し、Ｍｅ、ＬｏはそれぞれＭｅモード、Ｌｏモードを意味する。また、Ｎ、Ｆはそれぞれリレーのオンとオフを意味し、Ｎ／Ｆ、Ｆ／Ｎはそれぞれリレーのオンとオフを５分ごとに切り替えることを意味する。
以下、Ｈｉモード、Ｍｅモード、Ｌｏモードの詳細について説明する。 Next, control of the electric motors M1 to M8 that drive the evaporator fans B1 to B8 will be described.
The air conditioner 1 for buses controls the number of rotations of the electric motors M1 to M8 by the control circuit 19, and the amount of air blown from the evaporator fans B1 to B8 is the maximum blowing mode (hereinafter referred to as Hi mode). , Intermediate air blow mode (hereinafter referred to as Me mode), and minimum air blow mode (hereinafter referred to as Lo mode).
Specifically, switching between the Hi mode, the Me mode, and the Lo mode is performed by controlling ON / OFF (connection / disconnection) of the relay switches AR1 to AR14 of the control circuit 19 as shown in the table below. .

In the above table, Hi means Hi mode, and Me and Lo mean Me mode and Lo mode, respectively. N and F mean that the relay is turned on and off, respectively. N / F and F / N mean that the relay is turned on and off every 5 minutes.
Hereinafter, details of the Hi mode, the Me mode, and the Lo mode will be described.

FIG. 4 is a diagram illustrating a circuit configuration in the Hi mode in the control circuit of FIG.
In the control circuit 19 in the Hi mode, all relays of the relay switches AR1 to AR14 are connected as shown in FIG.

Specifically, in the first control circuit 21, the electric motor M1 has one terminal connected to the battery 25 by the relay switch AR1 and the other terminal connected to the ground G by the relay switch AR11. Electric motor M5 has one terminal connected to battery 25 by relay switch AR5.
Electric motor M2 has one terminal connected to battery 25 by relay switch AR2. Electric motor M6 has one terminal connected to battery 25 by relay switch AR6 and the other terminal connected to ground G by relay switch AR12.

  In the second control circuit 23, the electric motors M3 and M7 are connected to the battery 25 by the relay switch AR3 and connected to the ground G by the relay switches AR13 and AR14. Electric motors M4 and M8 are connected to battery 25 by relay switch AR24.

  By connecting all the relay switches AR1 to AR14 as described above, all the electric motors M1 to M8 are connected in parallel between the battery 25 and the ground G, and the voltage of the battery 25 (for example, 24V) is applied. Is done. Therefore, all the electric motors M1 to M8 rotate at the maximum rotation speed, and the air volume blown from the blower fans B1 to B8 can be maximized.

FIG. 5 is a diagram illustrating a circuit configuration in the Lo mode in the control circuit of FIG.
In the control circuit 19 in the Lo mode, the relay switches AR1 to AR14 are respectively connected and disconnected as shown in FIG.

Specifically, in the first control circuit 21, the electric motor M1 has one terminal connected to the battery 25 by connecting the relay switch AR1, and the other terminal connected to the electric motor M5 by connecting the relay switch AR11. Connected to one of the terminals. Electric motor M5 has one terminal disconnected from battery 25 by disconnecting relay switch AR5.
Electric motor M6 has one terminal connected to battery 25 by relay switch AR6 and the other terminal connected to one terminal of electric motor M2 by relay switch AR12. Electric motor M2 has one terminal disconnected from battery 25 by disconnecting relay switch AR2.

  In the second control circuit 23, one terminal of the electric motors M3 and M7 is connected to the battery 25 by the relay switch AR3, and the other terminal is connected to one terminal of the electric motors M4 and M8 by the relay switches AR13 and AR14. Connected. Electric motors M4 and M8 have one terminal disconnected from battery 25 by disconnecting relay switch AR4.

By connecting and disconnecting the relay switches AR1 to AR14 as described above, in the first control circuit 21, the electric motor M1 and the electric motor M5 are connected in series between the battery 25 and the ground G, and the electric motor M2 and the electric motor M6 are connected in series between the battery 25 and the ground G. In the second control circuit 23, the electric motors M3 and M7 and the electric motors M4 and M7 arranged in parallel are connected in series between the battery 25 and the ground G.
Therefore, about half of the voltage of the battery 25 (for example, 12V) is applied to all the electric motors M1 to M8, and the electric motors M1 to M8 rotate at a low rotation speed lower than the maximum rotation speed. When the rotation speed of the electric motors M1 to M8 decreases, the air volume blown from the blower fans B1 to B8 also decreases, and the Lo mode is set.

FIG. 6 is a diagram illustrating a circuit configuration in the Me mode in the control circuit of FIG.
In the control circuit 19 in the Me mode, the relay switches AR1 to AR14 are respectively connected and disconnected as shown in FIG.

Specifically, in the first control circuit 21, the electric motor M1 has one terminal connected to the battery 25 when the relay switch AR1 is connected, and the other terminal connected to the ground when the relay switch AR11 is connected. G is connected. Electric motor M5 has one terminal connected to battery 25 by connection of relay switch AR5.
The electric motor M6 has one terminal connected to the battery 25 when the relay switch AR6 is connected, and the other terminal connected to and disconnected from the ground G when the relay switch AR12 is connected and disconnected every 5 minutes. At the same time, it is disconnected and connected to one terminal of the electric motor M2. One terminal of the electric motor M2 is connected / disconnected to / from the battery 25 by connecting / disconnecting the relay switch AR2 every 5 minutes.

  In the second control circuit 23, the electric motors M3 and M7 have one terminal connected to the battery 25 when the relay switch AR3 is connected, and the relay switches AR13 and AR14 are disconnected and connected every 5 minutes. The other terminal is disconnected and connected to the ground G, and is connected and disconnected to one terminal of the electric motors M4 and M8. Electric motors M4 and M8 have one terminal disconnected and connected to battery 25 by relay switch AR4 being disconnected and connected every 5 minutes.

As described above, the electric motor M1 and the electric motor M5 are connected in parallel between the battery 25 and the ground G in the first control circuit 21 by connecting and disconnecting the relay switches AR1 to AR14. . On the other hand, in the electric motor M5 and the electric motor M2, the connection between the battery 25 and the ground G is switched between a series connection and a parallel connection every 5 minutes.
In the second control circuit 23, the electric motors M3 and M7 and the electric motors M4 and M8 arranged in parallel are connected in parallel and in series every 5 minutes between the battery 25 and the ground G. Can be switched to.

  Note that while the electric motor M5 and the electric motor M2 are connected in series in the first control circuit 21, the electric motors M3 and M7 and the electric motors M4 and M8 are connected in parallel in the second control circuit 23. . Conversely, while the electric motor M5 and the electric motor M2 are connected in parallel in the first control circuit 21, the electric motors M3 and M7 and the electric motors M4 and M8 are connected in series in the second control circuit 23. Yes.

  Therefore, the battery voltage (for example, 24V) is always applied to the electric motors M1 and M5, and the battery voltage and about half of the voltage (for example, 12V) are switched to the electric motors M2 and M6 every 5 minutes. Applied. The electric motors M3, M4, M7, and M8 are alternately applied with a voltage that is approximately half of the battery voltage and the battery voltage every 5 minutes.

  As a result, the electric motors M1 and M5 always rotate at the maximum number of revolutions, and when one of the electric motors M2 and M6 and the electric motors M3, M4, M7, and M8 rotates at the maximum number of revolutions, the other has a low revolution number. When one rotates at a low rotational speed, the other rotates at the maximum rotational speed. By rotating and driving the electric motor in this manner, the amount of air blown by the blower fans B1 to B8 can be set between the maximum airflow amount and the minimum airflow amount.

Next, an operation when any of the electric motors in the second control circuit 23 is locked will be described.
First, the case where the electric motors M3 and M7 arranged in parallel and the electric motors M4 and M8 are arranged in parallel as shown in FIG. 4 (in the Hi mode) will be described. For example, when one of the electric motors M3 and M7 is locked, the current flowing through the fuse F3 becomes excessive. Then, the fuse F3 is melted and the electric motors M3 and M7 are stopped.
When the fuse F3 is not blown, most of the current supplied to the electric motors M3 and M7 flows through the locked electric motor (for example, M3), and the electric motor (for example, M7) that is not locked has The remaining slight current flows. Therefore, almost no electric power is supplied to the electric motor that is not locked, and the electric motor does not rotate.
The same applies when either of the electric motors M4 and M8 is locked.

Next, the case where the electric motors M3 and M7 and the electric motors M4 and M8 arranged in parallel are arranged in series as shown in FIG. 5 (in the Lo mode) will be described. When any of the electric motors M3, M4, M7, and M8 is locked, the current flowing through the fuse F13 becomes excessive. Then, the fuse F13 is melted and the electric motors M3, M4, M7, and M8 are stopped.
For example, when either of the electric motors M3 and M7 is locked and the fuse F13 is not blown, most of the current supplied to the entire electric motors M3 and M7 flows through the locked electric motor (for example, M3). The remaining small current flows through the unlocked electric motor (for example, M7). Therefore, almost no electric power is supplied to the electric motor that is not locked, and the electric motor does not rotate. The electric motors M4 and M8 rotate normally.
This is the same when either of the electric motors M4 and M8 is locked.

Next, the operation when any of the electric motors in the first control circuit 21 is locked will be described.
First, the case where the electric motors M1 and M5 are arranged in parallel as shown in FIG. 4 (in the Hi mode) will be described. When one of the electric motors M1 and M5 is locked, an excessive current flows through the fuse connected to the locked electric motor. Then, the fuse is blown, and no current flows through the locked electric motor, so that the temperature of the electric motor can be prevented from rising.

Next, the case where the electric motors M1, M5 are arranged in series as shown in FIG. 5 (in the Lo mode) will be described. When one of the electric motors M1 and M5 is locked, the current supplied to the electric motors M1 and M5 increases, and an excessive current flows through the fuse F11. Then, the fuse F11 is blown, and the electric motors M1 and M5 are stopped.
The same applies to the electric motors M2 and M6.

According to the above configuration, in the second control circuit 23, the electric motors M3, M7 and the electric motors M4, M8 are connected in parallel between the battery 25 and the ground G in the Hi mode by the relay switches AR24, AR12, AR14. And in series in the Lo mode, the rotational speeds of the electric motors M3, M4, M7, and M8 can be controlled without using a register affected by heat. Therefore, the air volume can be controlled by controlling the rotation speed of the evaporator fans B3, B4, B7, and B8.
As a result, the vehicle air conditioner can exhibit a predetermined performance without performing a vehicle test or the like that is essential in a vehicle air conditioner using a conventional register.

  For example, when one of the electric motors M3 and M7 is locked, since the electric motors M3 and M7 are connected in parallel, most of the current flowing through the electric motors M3 and M7 flows to the locked electric motor and The remaining small current flows in the electric motor that is not. That is, when one of the electric motors M3 and M7 is locked, almost no current flows through the unlocked electric motor, and both the electric motors M3 and M7 do not rotate.

  Therefore, the blower fans B3 and B7 also do not rotate, and the flow rate of air blown to the evaporators 11 and 11 of the evaporator units 13R and 13L decreases. That is, even when one of the electric motors M3 and M7 is locked, it is possible to prevent an unbalance of the air flow rate blown to the evaporators 11 and 11.

As a result, when the frost sensor (temperature detection unit) for detecting the frost of the evaporator 11 is provided in the air conditioner 1 for buses, the air flow rates in the evaporators 11 and 11 are substantially the same, so the evaporator units 13R and 13L. By providing a frost sensor in any one of them, the frost of the evaporators 11 and 11 of both the evaporator units 13R and 13L can be detected.
The same applies when either of the electric motors M4, M8 is locked.

  A fuse F13 is arranged between the electric motors M3, M7 and the electric motors M4, M8 when the electric motors M3, M7 and the electric motors M4, M8 are connected in series (in the Lo mode). . Therefore, in the Lo mode, even if any of the electric motors M3, M4, M7, and M8 is locked, the fuse F13 is blown, so that no current flows through the electric motors M3, M4, M7, and M8. As a result, the temperature rise of the electric motors M3, M4, M7, M8 at the time of locking can be prevented.

  For example, when one of the electric motors M3 and M7 is locked, since the electric motors M3 and M7 are connected in parallel, most of the current flowing through the electric motors M3 and M7 flows to the locked electric motor and The remaining small current flows in the electric motor that is not. That is, when one of the electric motors M3 and M7 is locked, almost no current flows through the unlocked electric motor, and both the electric motors M3 and M7 do not rotate.

Therefore, the blower fans B3 and B7 also do not rotate, and the flow rate of air blown to the evaporators 11 and 11 of the evaporator units 13R and 13L decreases. That is, even when one of the electric motors M3 and M7 is locked, it is possible to prevent an unbalance of the air flow rate blown to the evaporators 11 and 11.
The same applies when either of the electric motors M4, M8 is locked.

In the first control circuit 21, since the electric motors M1 and M5 are connected in parallel between the battery 25 and the ground G in the Hi mode and connected in series in the Lo mode by the relay switches AR5 and AR11, The rotational speeds of the electric motors M1 and M5 can be controlled without using the affected register. Therefore, the air volume can be controlled by controlling the rotation speeds of the evaporator fans B1 and B5.
As a result, the vehicle air conditioner can exhibit a predetermined performance without performing a vehicle test or the like that is essential in a vehicle air conditioner using a conventional register.
The same applies to the electric motors M2 and M6.

In the first control circuit 21, when the electric motors M1 and M5 are connected in series (in the Hi mode), since the fuse F11 is disposed, even if any of the electric motors M1 and M5 is locked, Since the fuse F11 is blown, no current flows through the electric motors M1 and M5. As a result, the temperature increase of the electric motors M1, M5 at the time of locking can be prevented.
In addition, since the number of electric motors M1 stopped in the evaporator unit 13R and the number of electric motors M5 stopped in the evaporator unit 13L are the same, it is possible to prevent an unbalance in the air flow rate sent to the evaporators 11 and 11. .
The same applies to the electric motors M2 and M6.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the description has been made by applying to the configuration in which the rotation speed of the evaporator fan is controlled using the step motor as the electric motor, but in addition, the rotation speed of the evaporator fan is controlled using the power transistor. The present invention can be applied to various other configurations such as a configuration to be controlled and a configuration to be controlled by thermistor control.

It is the schematic explaining the whole structure of the air conditioner for buses which concerns on one Embodiment of this invention. It is a circuit diagram explaining the circuit structure of the air conditioner for buses of FIG. It is a circuit diagram explaining the control circuit of the evaporator fan in the air conditioner for buses of FIG. It is a figure explaining the circuit structure at the time of Hi mode in the control circuit of FIG. It is a figure explaining the circuit structure at the time of Lo mode in the control circuit of FIG. It is a figure explaining the circuit structure at the time of Me mode in the control circuit of FIG.

Explanation of symbols

1 Air conditioner for buses (air conditioner for vehicles)
3 Compressor 5 Capacitor (heatsink)
9 Expansion valve (pressure reducer)
11 Evaporator (heat absorber, one heat absorber, the other heat absorber)
19 Control circuit (fan control device)
25 Battery (Power)
M1, M2 electric motor (one third electric motor)
M5, M6 electric motor (the other third electric motor)
AR5, AR6, AR11, AR12 Relay switch (second connection part)
F11, F12, F13 Fuse (limitation part)
M3 electric motor (one first electric motor)
M7 electric motor (the other first electric motor)
M4 electric motor (one second electric motor)
M8 electric motor (the other second electric motor)
AR4, AR13, AR14 Relay switch (first connection part)

Claims (6)

A compressor for compressing the refrigerant;
A radiator that dissipates the heat of the compressed refrigerant;
A decompressor for reducing the pressure of the radiated refrigerant;
A vehicle air conditioner having at least two heat absorbers for absorbing heat by the decompressed refrigerant,
One first electric motor and one second electric motor for driving one blower fan and blowing air to one heat sink;
The other first electric motor and the other second electric motor that drive the other blower fan and blow air to the other heat absorber,
The one first electric motor and the other first electric motor are arranged in parallel to a power source, and the one second electric motor and the other second electric motor are arranged in parallel to the power source. Arranged,
A first connecting portion for switching and connecting the one and the other first electric motors and the one and the other second electric motors in series or in parallel to the power source;
In the maximum air blowing mode, the one and the other first electric motors and the one and the other second electric motors are connected in parallel to the power source by the first connecting portion,
In the minimum air blowing mode, the one and the other first electric motors and the one and the other second electric motors are connected in series to the power source by the first connecting portion. Air conditioner for vehicles. The compressor, the radiator, the decompressor, and the one and the other heat absorbers are connected to one refrigerant circuit,
2. The vehicle air conditioner according to claim 1, wherein a temperature detecting unit for measuring a temperature of the heat absorber is provided in at least one of the one heat absorber.   The one and the other first electric motors and the one and the other second electric motors when the one and the other first electric motors and the one and the other second electric motors are connected in series. The air conditioner for vehicles according to claim 1 or 2, wherein a restriction part for restricting current is provided between the two. One third electric motor that drives the one blower fan to blow air to the one heat sink;
The other third electric motor that drives the other blowing fan to blow air to the other heat absorber;
A second connecting portion that switches and connects the one third electric motor and the other third electric motor in series or in parallel to the power source;
In the maximum air blowing mode, the one third electric motor and the other third electric motor are connected in parallel to the power source by the first connection portion,
The said 3rd electric motor and the said other 3rd electric motor are connected in series with respect to the said power supply by the said 3rd connection part in the said minimum ventilation mode. The vehicle air conditioner according to any one of 3 above.   Limitation for limiting current between the one third electric motor and the other third electric motor when the one third electric motor and the other third electric motor are connected in series The vehicle air conditioner according to claim 4, wherein a portion is provided. One first electric motor and one second electric motor for driving one blower fan and blowing air to one heat sink;
The other first electric motor and the other second electric motor for driving the other blower fan and blowing air to the other heat absorber,
The one first electric motor and the other first electric motor are arranged in parallel to a power source, and the one second electric motor and the other second electric motor are arranged in parallel to the power source. Arranged,
A first connecting portion for switching and connecting the one and the other first electric motors and the one and the other second electric motors in series or in parallel to the power source;
In the maximum air blowing mode, the one and the other first electric motors and the one and the other second electric motors are connected in parallel to the power source by the first connecting portion,
In the minimum air blowing mode, the one and the other first electric motors and the one and the other second electric motors are connected in series to the power source by the first connecting portion,
The one and the other first electric motors and the one and the other second electric motors when the one and the other first electric motors and the one and the other second electric motors are connected in series. A ventilation control device for an air conditioner for a vehicle is provided with a limiting unit that limits the current between them.

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