JP3329097B2 - Vehicle air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner using a motor as a drive source of a refrigerant compressor in a refrigeration cycle, and more particularly to a vehicle air conditioner suitable for electric vehicles.

[0002]

2. Description of the Related Art An air conditioner for an electric vehicle has conventionally been provided with a refrigeration cycle including a hermetic refrigerant compressor having an AC motor built therein, and an inverter device for converting the output of a vehicle battery into AC power. And the above-mentioned motor is driven by this inverter device. According to such a configuration, since the motor for the refrigerant compressor can be driven at a variable speed by changing the output frequency of the inverter device, the refrigerant discharge amount from the refrigerant compressor, that is, the heat exchange capacity by the refrigeration cycle can be easily achieved. Advantages such as control can be obtained.

In the case of such an air conditioner for an electric vehicle,
PTC which is an electric heater as a heating source during heating operation
It is common to use a heater. That is, the refrigeration cycle is a cooling operation (a concept including a dehumidification operation).
If it is a dedicated one, a PTC heater is installed as a main heating source during a heating operation or a dehumidifying heating operation, and the refrigeration cycle can form a heat pump cycle for the heating operation. In such a case, the PTC heater is installed as an auxiliary heating source.

[0004]

In the conventional air conditioner for an electric vehicle, the power supply of the PTC heater is usually obtained directly from the on-board battery. Relays have been used as switching means for such purposes. In this case, since a relatively large DC current is interrupted by the relay, when a relay having a mechanical contact is used, the contact may be damaged by an arc when the contact is opened and the contact may be welded accordingly. There is a situation that the operation reliability related to the power cutoff control of the PTC heater is deteriorated. Therefore, conventionally, a so-called solid state relay is used to control the power cutoff of the PTC heater. However, since the solid state relay is more expensive than the mechanical relay, the cost of the entire apparatus is reduced. There was a problem of soaring. Further, such a problem also occurs when an anti-fog heater for heating a window glass of an automobile is provided.

[0005] In particular, when a PTC heater is used,
Since a DC voltage is continuously applied to the PTC heater, a metal forming an electrode of the PTC heater is deposited on a ceramic semiconductor portion constituting the PTC heater by a kind of electrolysis to form an impedance between the electrodes. There is a risk that a phenomenon (so-called migration) that causes a reduction in the temperature and a short circuit accident accompanying this may occur, and there is also a problem that operation reliability during long-term use is poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a mechanical device as switch means for turning on and off an electric heater used as a heating source for a predetermined portion of a vehicle. The present invention provides a vehicle air conditioner that can improve the reliability of the power cut-off control even when using a switch means having a contact, and has an effect of reducing the overall cost. is there.

[0007]

In order to achieve the above object, the present invention comprises a refrigeration cycle for air-conditioning operation, wherein the power supply of a motor for a refrigerant compressor in the refrigeration cycle is connected to the output of an on-vehicle battery. In a vehicle air conditioner obtained from an inverter device that converts electric power, an electric heater provided as a heating source for a predetermined portion of the vehicle,
A switch means for selectively supplying the output of the inverter device to the electric heater is provided (claim 1).

[0008] The electric heater can be a heater for heating operation for heating the atmosphere in the vehicle cabin (claim 2). In this case, the electric heater is a main heater for heating operation. After being provided as a heating source, the switch means may be configured to disconnect the motor for the refrigerant compressor from the inverter device when the output of the inverter device is switched to a state in which the output is supplied to the electric heater. Item 3).

Further, the refrigeration cycle is configured to be capable of forming a heat pump cycle for a heating operation, and the switch means is used to output the output of the inverter device when the heating capacity of the refrigeration cycle is insufficient. It may be configured to supply to both the motor for the refrigerant compressor and the electric heater (claim 4).

[0010] The electric heater may be an anti-fog heater for heating a window glass for a vehicle.

[0011] Further, the inverter device is configured to generate a multi-phase AC output, and a plurality of electric heaters to which a multi-phase AC output inter-phase voltage is applied by the inverter device; A plurality of switch means corresponding to the heater may be provided (claim 6).

[0012]

In the vehicle air conditioner according to the first aspect, the output of the onboard battery is converted into AC power by the inverter device, and the converted output drives the motor for the refrigerant compressor in the refrigeration cycle. Further, for an electric heater provided as a heating source for a predetermined portion of a vehicle,
The converted output from the inverter device is selectively supplied through the switch means. In this case, the switch means for turning on and off the electric heater interrupts the alternating current. Therefore, even when the switch means is provided with a mechanical contact, even if the switch means is provided with a mechanical contact, an arc generated when the contact is opened. Contact damage is reduced compared to when the DC current is interrupted. As a result, it is possible to use a low-cost switch provided with a mechanical contact as the switch means.

According to the second aspect of the present invention, during the heating operation, the conversion output of the inverter device is selectively supplied to the electric heater through the switch means, so that the atmosphere in the vehicle compartment is heated. . Generally, a PTC heater is used as an electric heater for such a heating operation. However, since an AC voltage is applied to the electric heater, a PTC heater is used as the electric heater.
Even when the TC heater is used, there is no danger of occurrence of the migration phenomenon unlike the conventional configuration, and the operation reliability in long-term use is improved.

In the vehicle air conditioner according to the third aspect, during the heating operation, the motor for the refrigerant compressor is disconnected from the inverter by the switch means, and in this state, the output of the inverter is provided as the main heating source. To the electric heater. Accordingly, a change in the output of the inverter device is directly linked to a change in the output of the electric heater, so that the heating capacity of the electric heater can be easily adjusted.

In the vehicle air conditioner of the present invention, the heating operation is performed by the refrigeration cycle functioning as a heat pump cycle. When the heating capacity is insufficient at this time, the switch means switches the output of the inverter device. In addition to the motor for the refrigerant compressor for the refrigeration cycle, the electric power is supplied to the electric heater, and the heat generated by the electric heater accompanying this causes the shortage of the heating capacity as described above to be eliminated or supplemented. In this case, the switch means may have a simple configuration in which the electric heater is brought into contact with and separated from the output side of the inverter device, and furthermore, the current flowing through the electric heater provided as an auxiliary heating source (that is, the electric heater Less current than when used as main heating source)
, The structure can be simplified and the contact capacity can be reduced, so that the cost of the switch means can be further reduced, and contact damage due to arcing is reduced.

In the air conditioner for a vehicle according to the present invention, when an anti-fog operation of the window glass is performed (this concept also includes an operation for removing fogging that has already adhered), an inverter device is provided for the electric heater. Is selectively supplied through the switch means, so that the window glass is heated, whereby the anti-fog operation of the window glass is performed.

In the vehicle air conditioner according to the present invention, the inverter device generates a multi-phase AC output, and when heating a predetermined portion of the vehicle, the inter-phase voltage of the multi-phase AC output is a plurality of times. The electric power is supplied to a plurality of electric heaters via the switch means. In this case, the current flowing through each electric heater can be reduced, so that there is an advantage that the switch means can have a small contact capacity and is hardly damaged by the arc.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to an air conditioner for an electric vehicle will be described below with reference to FIGS. FIG. 3 schematically shows a blowing system of the electric vehicle air conditioner. In FIG. 3, the air duct 1
Is provided with an inside air inlet 3 and an outside air inlet 4 which are opened and closed by an inside / outside air switching damper 2 at the uppermost stream portion, and each outlet (defroster outlet) opened in the vehicle compartment on the downstream side. 5, a center face outlet 6, a pair of left and right side face outlets 7, and a foot outlet 8) are connected to branch ducts 9 to 12 for guiding conditioned air, respectively.

Among the branch ducts 9 to 12, the upstream openings of the branch ducts 9, 10 and 12 are means for adjusting the proportion of the amount of air flowing into the branch ducts 9, 10 and 12, for example. Plate-shaped outlet dampers 9a, 10a and 12a are provided. Further, the most downstream side of the branch ducts 10 and 11 has a corresponding center face outlet 6.
For example, plate-like opening / closing dampers 10b and 11a, which are means for opening and closing the side face outlet 7, are provided.

In the air duct 1, for example, a blower 13 which is a blowing means is provided at a position corresponding to the inside air inlet 3 and the outside air inlet 4, and a cooling means such as a refrigerating cycle evaporator is provided downstream thereof. The vessel 14 is arranged. Further, on the downstream side of the evaporator 14 in the air duct 1, for example, three PTC heaters 15 (corresponding to an electric heater in the present invention) are arranged. In this case, the PTC heater 15 is provided as a main heating source for heating the air blown by the blower 13 and thus the atmosphere in the vehicle compartment during the heating operation. Although not shown, each PTC heater 15 is formed by sandwiching a ceramic semiconductor having a positive temperature resistance characteristic between a pair of electrodes. Of the heat radiation fin.

FIG. 4 shows the piping configuration of the refrigeration cycle for air-conditioning operation including the evaporator 14 together with a part of a blower system related to the evaporator 14. In FIG. 4, the refrigerant compressor 16 is a three-phase AC motor 1
6a (corresponding to the motor for the refrigerant compressor in the present invention) is built in a sealed type, and the refrigerant discharge amount changes according to the AC motor 16a being operated at a variable speed by an inverter device described later. It has a configuration. In this case, the high-temperature and high-pressure vaporized refrigerant discharged from the refrigerant compressor 16 is supplied to the outdoor heat exchanger 17 having the radiating fan device 17a.
After being radiated and liquefied through a pressure reducing device 18 (an example of a capillary tube is shown in the figure, but may be an expansion valve, etc.), it is supplied to the evaporator 14,
A cycle is formed in which the gas is vaporized in 4 and returned to the compressor 16 via the accumulator 19. In the case of the present embodiment, the outdoor heat exchanger 17 functions as a refrigerant condenser. Also, the refrigerant compressor 16 is housed in the unit case together with the accumulator 19,
The compressor unit 20 is configured.

FIG. 2 schematically shows an electric configuration of an air conditioner for an electric vehicle. 2, the inverter device 21 receives the output of the vehicle-mounted battery 22 via a fuse 23 and a power switch 24 also serving as a blower switch, for example. AC motor 16 for refrigerant compressor 16 by three-phase AC output of voltage and variable frequency
a is driven at a variable speed. The inverter device 21 may be of any type as long as it can perform variable-speed driving of the three-phase AC motor 16a. Here, for example, a three-phase PWM inverter is used, and its output torque is controlled. Is controlled by a constant voltage / frequency control (so-called V /
f control) using open loop control.

The operation of the inverter 21 is controlled by E
The control is performed by a control device 25 constituted by a CU (Electronic Control Unit). The control device 25 includes a C for detecting an input current of the inverter device 21.
A detection output from a current sensor 26 made of T or the like is provided. In this case, the control device 25
Is configured to perform an overcurrent protection operation of, for example, forcibly stopping the operation of the inverter device 21 when the current detected by the current sensor 26 exceeds a preset upper limit level.

Here, FIG. 2 shows that the output of the inverter device 21 is supplied only to the AC motor 16a, but in practice, as shown in FIG. The power can also be supplied to the three PTC heaters 15 via relay switches 26R, 26S, and 26T that are simultaneously switched and controlled by the device 25. In this case, the relay switches 26R, 26S, and 26T are provided with mechanical transfer contacts, and apply a three-phase AC output voltage from the inverter device 21 to the AC motor 16a and a state between the three-phase AC output phases. The configuration is such that the state is switched to any one of a state in which the voltage is applied to the three PTC heaters 15 connected in delta. Therefore, when the AC motor 16a is energized (the operation state of the refrigerant compressor 16), the PTC heater 15 is disconnected from the inverter device 21, and when the PTC heater 15 is energized, the AC motor 16
a is disconnected from the inverter device 21.

Returning to FIG. 2, the control device 25 receives an operation signal (a temperature setting signal, a blow-off air volume setting signal, an operation mode switching signal, a blowing mode switching signal, an inside air circulation / outside air introduction mode switching signal) from the control panel 27. Etc.), a refrigerant temperature detection signal from a discharge temperature thermistor 28 for detecting the temperature of the refrigerant discharged from the refrigerant compressor 16, an outside air temperature detection signal from an outdoor temperature thermistor 29 for detecting the temperature outside the vehicle compartment, For example, a pressure detection signal from a pressure sensor 30 for detecting the refrigerant pressure upstream of the pressure reducing device 18 is provided.

The control device 25 is operated in a state where the power switch 24 is turned on. In the operation state, the control device 25 drives the blower 13 at a speed corresponding to a blow air volume setting signal from the control panel 27. It has become. Further, in the above operation state, the control device 25 controls the output of the inverter device 21, the operation control of the radiating fan device 17a, the relays 26R, 26S, 26T of the PTC heater 15 based on the input signals as described above.
To control the operation of a group of servomotors 31 for controlling the opening / closing of the inside / outside air switching damper 2, the air outlet dampers 9a, 10a and 12a, and the opening / closing dampers 10b and 11a. I have.

The main control contents of the control device 25 as described above are as listed below. (1) It is determined whether the cooling mode or the heating mode has been selected based on the operation mode switching signal from the control panel 27, and when the cooling mode has been selected, the relay switch relays 26R, 26S, and 26T are exchanged. By switching to the motor 16a side, the inverter device 21
Is supplied to the AC motor 16a. As a result, the refrigerant compressor 16 is driven to supply the liquefied refrigerant to the evaporator 14, so that the air blown by the blower 13 is cooled by the evaporator 14. still,
In this case, control is performed to increase the output frequency of the inverter device 21 as the temperature value indicated by the temperature setting signal from the control panel 27 decreases (in this case, V / f control is performed. And its output voltage will also increase). Thereby, the lower the set temperature, the higher the rotational speed of the AC motor 16a, and the refrigerant compressor 1
As the amount of refrigerant discharged from 6 increases, the cooling capacity increases.

(2) When the heating mode is selected,
PTC relay switch relay 26R, 26S, 26T
By switching to the heater 15 side, the inverter device 2
1 is supplied to the PTC heater 15. As a result, the PTC heater 15 generates heat, and the air blown by the blower 13 is heated by the PTC heater 15. In this case, the three-phase AC output voltage from the inverter device 21 is supplied to the three PTC heaters 15 by 2π.
Therefore, it is applied with a phase difference of / 3. The output voltage of the inverter device 21 is controlled by the control panel 27.
The output of the PTC heater 15 may be controlled by changing the temperature in accordance with the temperature value indicated by the temperature setting signal from the PTC heater 15.

(3) The inside / outside air switching damper 2 is controlled through the servomotor 31 so as to be in a position corresponding to the inside air circulation / outside air introduction mode switching signal from the control panel 27, and the outlet dampers 9a, 10a and 12a.
Is controlled through the servomotor 31 so as to be at a position corresponding to the air blowing mode switching signal from the control panel 27.

(4) When the temperature of the refrigerant discharged from the refrigerant compressor 16 indicated by the refrigerant temperature detection signal from the discharge temperature thermistor 28 exceeds a preset upper limit temperature,
By lowering the output frequency of the inverter device 21 to protect the AC motor 16a, the abnormal increase in the refrigerant temperature is suppressed.

(5) The capability of the radiating fan device 17a is switched based on the outdoor temperature indicated by the outdoor temperature detection signal from the outdoor temperature thermistor 29. In particular,
In the state in which the cooling mode is selected, when the outside temperature of the vehicle indicated by the outside air temperature detection signal rises to, for example, 25 ° C. or more, the air blowing amount of the radiating fan device 17a is increased, and the condensation capacity of the outdoor heat exchanger 17 is increased. Is increased, and when the outside temperature of the vehicle falls to, for example, 22 ° C. or lower, differential control is performed such that the amount of air blown by the radiating fan device 17a is reduced to lower the condensation capacity of the outdoor heat exchanger 17. still,
When the configuration in which the heating operation is performed by using the heat pump cycle is adopted, during the heating operation, the outside temperature of the vehicle indicated by the outside air temperature detection signal from the outdoor temperature thermistor 29 decreases to, for example, 12 ° C. or less. Sometimes, the amount of air blown by the radiating fan device 17a is increased to increase the condensation capacity of the outdoor heat exchanger 17 (that is, the amount of heat absorbed by the heat pump cycle). A configuration is employed in which differential control is performed such that the amount of air blown from the device 17a is reduced to reduce the condensation capacity of the outdoor heat exchanger 17.

(6) The refrigerant pressure upstream of the pressure reducing device 18 indicated by the pressure detection signal from the pressure sensor 30 (this can be regarded as equivalent to the refrigerant pressure in the outdoor heat exchanger 17)
When the pressure exceeds a preset upper limit pressure, an abnormal increase in the refrigerant pressure is suppressed by decreasing the output frequency of the inverter device 21.

According to the configuration of the present embodiment described above, the AC output from the inverter device 21 is supplied to the PTC heater 15 during the heating operation. Therefore, in the PTC heater 15, there is no possibility that the migration phenomenon caused by the application of the DC voltage occurs, and the operation reliability in long-term use is improved.

Further, the relay switches 26R, 26S, 26T for turning on and off the PTC heater 15 interrupt the alternating current, so that when the contact is damaged by the arc when the contacts are opened, the DC current is interrupted. It will be reduced in comparison. As a result, the relay switches 26R, 26R
The use of low-cost switch means having mechanical contacts, such as S and 26T, does not cause any trouble, and the overall cost can be reduced. In this case, since the three-phase AC output inter-phase voltage from the inverter device 21 is applied to the three PTC heaters 15, the current flowing through each PTC heater 15 is reduced. As a result, the relay switches 26R, 26S, and 26T can be reduced in contact capacity, and the relay switches 26R, 26S, and 26T are less likely to be damaged by an arc. Become.

Further, during the heating operation, the AC motor 16a for the refrigerant compressor 16 is disconnected from the inverter device 21 and the output of the inverter device 21 is supplied to the PTC heater 15 in this state. The output change of the device 21 will be directly linked to the output change of the PTC heater 15. Therefore, by changing the output voltage of the inverter, the heating capacity of the PTC heater 15 can be easily adjusted.

In the first embodiment, three PTs are used.
Although the configuration is such that the C heaters 15 are used in a delta connection, as shown in FIG. 5 showing a second embodiment of the present invention, a configuration in which three PTC heaters 15 are used in a star connection (Y connection) may be used.

FIGS. 6 to 9 show a third embodiment of the present invention. Only the portions different from the first embodiment will be described below. That is, the third embodiment uses a refrigeration cycle for air-conditioning operation capable of forming a heat pump cycle for heating operation, and uses the PTC heater 15 for auxiliary heating when the heating capacity of the refrigeration cycle is insufficient. It is characterized in that it is used as a source.

More specifically, in the air blowing system of the electric vehicle air conditioner shown in FIG.
Upstream position of C heater 15 (downstream position of evaporator 14)
The auxiliary heat exchanger 32 is arranged to perform a function of a refrigerant condenser when the heat pump cycle is formed, so that the auxiliary heat exchanger 32 is used as a heat source during a heating operation.

In the piping configuration of the refrigeration cycle shown in FIG. 9, the refrigerant compressor 16 is housed in a unit case together with the accumulator 19 and the four-way valve 33 constituting the flow path switching means, so that the compressor unit 20 'is provided. Is configured as The four-way valve 33 is connected to the refrigerant compressor 16.
Is switched between a first state in which the refrigerant discharged from the refrigerant is supplied to the outdoor heat exchanger 17 via the check valve 34 and a second state in which the refrigerant is supplied to the auxiliary heat exchanger 32. . When the four-way valve 33 is switched to the first state, the branch point 19a upstream of the accumulator 19 is connected to the auxiliary heat exchanger 32 via the four-way valve 33, and the four-way valve 33 is in the second state. Is switched to the outdoor heat exchanger 17 via the check valve 34.

The auxiliary heat exchanger 32 has a refrigerant discharge port which is connected to the outdoor heat exchanger 17 via an auxiliary pressure reducing device 35 (an example of a capillary tube is shown in the figure, but may be an expansion valve) and a check valve 36. It is connected to the refrigerant inlet.

The first solenoid valve 37 is configured as an on-off valve, and converts the refrigerant discharged from the outdoor heat exchanger 17 functioning as a refrigerant evaporator during the heating operation to the pressure reducing device 1.
8 and the evaporator 15 are bypassed to accumulator 19
It is configured to return to the side. Also, the second solenoid valve 38
This is also configured as an open / close valve, and allows the refrigerant discharged from the auxiliary heat exchanger 32 functioning as a refrigerant condenser during the dehumidifying operation to flow into the outdoor heat exchanger 17 by bypassing the auxiliary pressure reducing device 35. Is configured.

In the refrigeration cycle configured as described above, the four-way valve 33, the first solenoid valve 37, and the second solenoid valve 38
, The flow of the refrigerant is controlled as described below, and the heating operation, the cooling operation, and the dehumidifying operation are realized.

Specifically, during the cooling operation, the four-way valve 33
Is switched to the first state, and the first solenoid valve 37 is switched to the closed state (the second solenoid valve 38 may be disconnected), as shown by the arrow C in the figure. The refrigerant discharged from 16 is supplied to a four-way valve 33 → a check valve 34.
→ The outdoor heat exchanger 17 → the pressure reducing device 18 → the evaporator 14 → the accumulator 19 → the refrigerant compressor 16 flow in this order.

As a result, the liquefied refrigerant is supplied to the evaporator 14, so that the air blown by the blower 13 is cooled by the evaporator 14. In this case, the branch point 19a upstream of the accumulator 19 is connected to the auxiliary heat exchanger 32 via the four-way valve 33. In this state, the check valve 36 opens the refrigerant passage based on the pressure difference. Since it is closed, the flow of refrigerant into the auxiliary heat exchanger 32 is substantially prevented.

During the heating operation, the four-way valve 33 is switched to the second state, the first solenoid valve 37 is switched to the open state, and the second solenoid valve 38 is switched to the closed state, as shown by the arrow H in the figure. The refrigerant discharged from the refrigerant compressor 16 is supplied to the four-way valve 33 → the auxiliary heat exchanger 32 → the auxiliary pressure reducing device 35.
The check valve 36, the outdoor heat exchanger 17, the first solenoid valve 37, the accumulator 19, and the refrigerant compressor 16 flow in this order.

Thus, the high-temperature vaporized refrigerant is supplied to the auxiliary heat exchanger 32 and the liquefied refrigerant is supplied to the outdoor heat exchanger 17. That is, the auxiliary heat exchanger 32 functions as a refrigerant condenser, and heat is exchanged between the air blown by the blower 13 and the auxiliary heat exchanger 32, so that the air blown is heated. Become. Further, the outdoor heat exchanger 17 functions as an evaporator that exchanges heat with the air blown from the fan device 17a. In this case, the branch point 19a upstream of the accumulator 19 is connected to the outdoor heat exchanger 17 via the four-way valve 33. In this state, the check valve 34 connects the refrigerant passage based on the pressure difference. Since it is closed, the refrigerant is substantially prevented from flowing into the outdoor heat exchanger 17.

In the dehumidifying operation, the four-way valve 33 is switched to the second state, the first solenoid valve 37 is switched to the closed state, and the second solenoid valve 38 is switched to the open state, whereby an arrow D in the figure is obtained.
As shown by, the refrigerant discharged from the refrigerant compressor 16 is:
Four-way valve 33 → auxiliary heat exchanger 32 → second solenoid valve 38 → check valve 36 → outdoor heat exchanger 17 → pressure reducing device 18 → evaporator 14
It flows in the order of → accumulator 19 → refrigerant compressor 16.
In this case, the radiation fan device 17a is stopped.

Thus, the high-temperature vaporized refrigerant is supplied to the auxiliary heat exchanger 32 and the liquefied refrigerant that has passed through the pressure reducing device 18 is supplied to the evaporator 14. Therefore, in this case, the air blown by the blower 13 is once cooled in the evaporator 14 and then heated by the auxiliary heat exchanger 32. Therefore, in accordance with a decrease in the saturated steam temperature when the air blown by the blower 13 exchanges heat with the evaporator 14, moisture in the blown air is condensed on the surface of the evaporator 14 and removed. Thereafter, as the blast air is reheated by exchanging heat with the auxiliary heat exchanger 32, the relative humidity is greatly reduced.

The four-way valve 33 and the first solenoid valve 37 as described above
The control of the second solenoid valve 38 is performed by the control device 25 as shown in FIG. The control function of the control device 25 is basically the same as that of the first embodiment, but especially in the heating operation, for example, the refrigerant in the auxiliary heat exchanger 32 based on the pressure detected by the pressure sensor 30. The condensing temperature is calculated, and based on the calculation result, the inverter device 2
By adjusting the output frequency of No. 1, the condensing temperature, that is, the heating temperature is controlled.

As shown in FIG. 6, the output of the inverter device 21 is always supplied to the AC motor 16a and is controlled by the control device 25 at the same time via relay switches 39R, 39S, and 39T. Three P
It can be supplied to the TC heater 15 as well. In this case, the relay switches 39R, 39S, and 39T have mechanical make contacts.
The three-phase AC output of the inverter device 21 is switched to a state in which it is applied to three delta-connected PTC heaters 15 with a phase difference of 2π / 3. That is, according to the control of the relay switches 39R, 39S, and 39T, the configuration can be switched between a state where only the AC motor 16a is energized and a state where both the AC motor 16a and the PTC heater 15 are energized.

Therefore, in the present embodiment having the above-described configuration, during the heating operation, the AC motor 16a for the refrigerant compressor 16 is energized, and the four-way valve 33, the first solenoid valve 37, and the second solenoid valve 38 are set to predetermined positions. By switching to the state, the refrigeration cycle functions as a heat pump cycle. When the heating capacity is insufficient at this time, the relay switches 39R, 39S, and 39T are turned on, and the output of the inverter device 21 is changed to the AC power. The PTC heater 15 is also provided to the motor 16a in addition to the motor 16a, and the heat generated by the PTC heater 15 causes the shortage of the heating capacity as described above to be eliminated or supplemented.

In this case, in this embodiment, the PTC heater 1
5 is provided with an AC output from the inverter device 21 and the like, so that the same effects as in the first embodiment can be obtained. In particular, in the present embodiment, the relay switches 39R, 39S, and 39T may be configured to have a simple make-up contact for simply connecting and disconnecting the PTC heater 15 to and from the output side of the inverter device 21. It is only necessary to interrupt the current flowing through the PTC heater 15 provided as a general heating source (that is, less current than when the PTC heater 15 is used as the main heating source as in the first embodiment). There is an advantage that the simplification and small contact capacity can be achieved, the cost of the relay switches 39R, 39S, and 39T can be reduced, and the contact damage due to the arc can be reduced.

In the above embodiment, three PTC heaters 15 are used in a delta connection. However, similar to the second embodiment, the three PTC heaters 15 are connected in a star connection (Y connection). Needless to say, a configuration may be used.

FIGS. 10 to 13 show a fourth embodiment of the present invention, and only the portions different from the first embodiment will be described below. That is, this embodiment is characterized in that a heated windshield, which is a kind of an anti-fog heater for heating window glass of an electric vehicle, is driven by an inverter device.

More specifically, as shown in FIG. 12, for example, a front window glass 40 showing a part of its cross-sectional structure in an enlarged state is made of laminated glass. Has a three-layer structure in which an intermediate layer 43 mainly made of resin is interposed. In this case, the inner surface of the outer glass 41 (the contact surface with the intermediate layer 43)
Is a transparent conductive film 4 mainly composed of an evaporated film of an Ag alloy.
4 is provided, and a power supply electrode (only the first electrode 45a is shown in FIG. 12) is provided at both upper and lower ends of the transparent conductive film 44, so that a heated window capable of heating the entire window glass 40 is provided. A shield 46 (corresponding to an electric heater according to the present invention) is configured.

More specifically, as shown in FIG. 13, a first electrode 45a formed substantially over the entire upper end portion of the transparent electrode film 44 and a lower end portion of the transparent electrode film 44 are separated from each other. Second electrodes 45b each having a predetermined width dimension formed by
And a third electrode 45c, whereby R is provided between each of the electrodes 45a to 45c in FIG.
Virtual resistance indicated by a, Rb, and Rc (equivalent to electric heater)
Exist in a delta connection. As shown in FIG. 12, the black ceramic films 41a and 4c are formed on the opposing surfaces of the outer glass 41 and the inner glass 42 so as to cover the first electrode 45a to the third electrode 45c from the front and rear.
2a is provided.

However, as shown in FIG.
In the Ted windshield 46, a first electrode 45a, a second electrode 45b, and a third electrode 45c are connected to respective phase output terminals of the inverter device 21 via relay switches 47R, 47S, and 47T, respectively. The relay switches 47R, 47S and 47T have mechanical make contacts.

As shown in FIG. 11, an HWS switch 48 for turning on and off the heated windshield 46 is provided at a position where the driver can operate the HWS switch 48. Relay switches 47R, 47S, 47 according to the on / off operation of
T is turned on and off. Therefore, the inverter device 2 is connected to the heated windshield 46.
1 can be selectively supplied via the relay switches 47R, 47S, and 47T. The HWS switch 48 may be used also as a defrost switch.

According to the configuration of the present embodiment described above, according to the control of the relay switches 47R, 47S, 47T, the state where only the AC motor 16a is energized,
And the state in which both the heated windshield 46 and the heated windshield 46 are energized, whereby frost, ice, fogging due to moisture, etc. attached to the window glass 40 can be removed as necessary. In this case, the power consumption of the heated windshield 46 is relatively large (about 1000 to 1500 W / m ² ).
Relay switches 47R, 47S, 47 that perform the cutoff
T is the relay switch 26R, 26 in the first embodiment.
As in the case of S and 26T, the alternating current is interrupted, so that the contact damage due to the arc at the time of opening the contact is reduced as compared to when the direct current is interrupted, even though the current is interrupted. become. As a result, the use of low-cost switch means having mechanical contacts such as the relay switches 47R, 47S, and 47T does not cause any trouble, and the overall cost can be reduced.

When the load to be controlled is the heated windshield 46, the power supply is generally performed independently of the air-conditioning operation. It is also possible to configure so as to obtain from an inverter device for driving a motor.

FIG. 14 shows a fifth embodiment of the present invention in which a change in the circuit configuration is added to the fourth embodiment, and only different portions will be described below. That is, the fifth embodiment is different from the fourth embodiment in that
Instead of R, 47S, 47T, relay switches 49R, 49S, 49T having mechanical transfer contacts are provided, and these relay switches 49R, 49S, 49T are
The three-phase AC output voltage from the inverter device 21 is applied to the AC motor 16a and the inter-phase voltage of the three-phase AC output is applied to the heated windshield 46. is there.

According to such a configuration, the AC motor 16
a and the heated windshield 46 are not energized at the same time.
6 can be arbitrarily changed.

FIGS. 15 and 16 show a sixth embodiment of the present invention. That is, in FIG. 16, the heated windshield 50 (corresponding to the electric heater in the present invention) in this embodiment has a shape covering almost the entire upper and lower ends of the transparent electrode film 44 provided on the window glass 40. A pair of formed electrodes 50a and 50b is provided, and between the electrodes 50a and 50b, FIG.
A virtual resistance indicated by Rz is present therein.

As shown in FIG. 15, the above-mentioned heated windshield 50 is composed of a pair of relay switches 51 provided with mechanical transfer contacts from the inverter device 21.
It is connected so as to be energized via R and 51S. still,
In this case, the output mode of the inverter device 21 is changed so that the inverter device 21 functions as a two-phase or single-phase inverter when the heated windshield 50 is energized.

FIG. 17 shows a seventh embodiment of the present invention, which will be described below. That is, FIG. 17 schematically shows the arrangement of all the window glasses of the electric vehicle. Each of the front window glass 51, the rear window glass 52, and the window glass 53 provided on the driver's seat door has a head glass. Ted Windshield 51A,
52A and 53A (corresponding to the electric heater in the present invention)
And the heated windshield 5
1A, 52A and 53A are connected in a star connection, for example, and the three-phase AC output voltage from the inverter device 21 is applied to the relay switches 47R, 47S, 47T as in the fourth embodiment or the relay switch 49R as in the fifth embodiment. , 49
It is configured to be supplied via S, 49T.

In addition, the present invention is not limited to the above embodiments, and the following modifications or extensions are possible. In each of the above embodiments, the present invention is applied to a manual type air conditioner. However, the present invention is also applicable to an automatic type air conditioner, and is not limited to an electric vehicle. The present invention can be applied to general automobiles employing a driving configuration. As the electric heater, not only the PTC heater but also other types of heaters can be widely used, and the number of electric heaters is not limited to three as in the above-described embodiment. If cost does not need to be considered, a non-contact type switching element (triac, thyristor connected in antiparallel, etc.) may be used as the switch means. Although the heated windshield is used as an anti-fog heater, other types of anti-fog heaters such as a hot wire heater may be used.

[0067]

As is apparent from the above description, according to the first aspect of the present invention, the power source of the electric heater provided as a heating source for a predetermined portion of the vehicle is changed to the motor for the refrigerant compressor in the refrigeration cycle. Since the configuration is obtained from the inverter device provided as the power supply through the switch means, even when the switch means having a mechanical contact is used as the switch means, the reliability of the power cutoff control can be improved. Thus, the overall cost can be reduced.

According to the second aspect of the present invention, since the electric heater is a heater for heating operation for heating the atmosphere in the vehicle cabin, the most general PTC heater is used as the electric heater for heating. Even in this case, there is no possibility that a migration phenomenon occurs, and it is possible to improve the operation reliability in long-term use.

According to the third aspect of the present invention, when the electric heater is provided as a main heating source during the heating operation, and when the output of the inverter device is supplied to the electric heater, the switch means is used for the refrigerant compressor. The motor is separated from the inverter device, so that the output change of the inverter device is directly linked to the output change of the electric heater, so that the heating capacity of the electric heater can be easily adjusted. In the invention, the refrigeration cycle is configured to be capable of forming a heat pump cycle for heating operation, and when the heating capacity of the refrigeration cycle is insufficient, the output of the inverter device is switched by the switch means to the motor for the refrigerant compressor and Since the configuration is such that power is supplied to both electric heaters, the structure of the switch means is simplified and the contact capacity is reduced. Turned so that, it is possible reduce the cost of the switch means, it becomes possible to suppress the contact damage arc.

According to the fifth aspect of the present invention, the electric heater is an anti-fog heater for heating a window glass for a vehicle. Even in the case of using a switch having a mechanical contact for power supply, the reliability of the power cutoff control can be improved, and the overall cost can be reduced.

According to the present invention, the inverter device is configured to generate a multi-phase AC output.
Since a plurality of electric heaters to which the interphase voltage of the polyphase AC output is applied and a plurality of switch means corresponding to each electric heater are provided, the current flowing through each electric heater can be reduced. In addition, the switch means can have a small contact capacity and can be hardly damaged by the arc.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram of main parts showing a first embodiment of the present invention.

FIG. 2 is an overall electrical configuration diagram.

FIG. 3 is a cross-sectional view schematically showing a blowing system.

FIG. 4 is a piping configuration diagram of a refrigeration cycle.

FIG. 5 is a view corresponding to FIG. 1 showing a second embodiment of the present invention.

FIG. 6 is a view corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 7 is a diagram corresponding to FIG. 2;

FIG. 8 is a diagram corresponding to FIG. 3;

FIG. 9 is a diagram corresponding to FIG. 4;

FIG. 10 is a view corresponding to FIG. 1, showing a fourth embodiment of the present invention;

FIG. 11 is a diagram corresponding to FIG. 2;

FIG. 12 is a schematic longitudinal sectional view showing the heated windshield in a partially enlarged state.

FIG. 13 is a diagram schematically showing a heated windshield.

FIG. 14 is a view corresponding to FIG. 1, showing a fifth embodiment of the present invention.

FIG. 15 is a view corresponding to FIG. 1, showing a sixth embodiment of the present invention.

FIG. 16 is a diagram corresponding to FIG. 13;

FIG. 17 is a view corresponding to FIG. 13 showing a seventh embodiment of the present invention.

[Explanation of symbols]

In the drawings, 1 is an air duct, 13 is a blower, 14 is an evaporator, 15 is a PTC heater (electric heater), 16 is a refrigerant compressor, 16a is an AC motor (motor for a refrigerant compressor),
17 is an outdoor heat exchanger, 21 is an inverter device, 22 is a vehicle-mounted battery, 25 is a control device, 26R, 26S, 26
T, 39R, 39S, 39T, 47R, 47S, 47
T, 51R, 51S are relay switches (switch means), 40, 51, 52, 53 are window glasses,
Reference numerals 6, 50, 51A, 52A, and 53A denote heated windshields (electric heaters).

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-229334 (JP, A) JP-A-5-178069 (JP, A) JP-A-5-178061 (JP, A) 254334 (JP, A) JP-A-5-147428 (JP, A) JP-A-5-312029 (JP, A) JP-A 5-91922 (JP, U) JP-A 5-91925 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60H 1/22 611

Claims (6)

(57) [Claims] 1. A refrigeration cycle for air-conditioning operation,
In a vehicle air conditioner configured to obtain power of a motor for a refrigerant compressor in the refrigeration cycle from an inverter device that converts an output of an on-vehicle battery into AC power, an electric air conditioner provided as a heating source for a predetermined portion of the vehicle An air conditioner for a vehicle, comprising: a heater; and switch means for selectively supplying an output of the inverter device to the electric heater. 2. The air conditioner for a vehicle according to claim 1, wherein the electric heater is a heater for heating operation for heating an atmosphere in a vehicle cabin. 3. The refrigerant compressor is provided as a main heating source during a heating operation, and the switch means is configured to switch the refrigerant compressor when a state in which an output of the inverter is supplied to the electric heater. The vehicle air conditioner according to claim 2, wherein the vehicle motor is configured to be separated from the inverter device. 4. The refrigeration cycle is configured to be capable of forming a heat pump cycle for a heating operation, and the switch means outputs the output of the inverter device to the refrigerant compressor when the heating capacity of the refrigeration cycle is insufficient. 3. The vehicle air conditioner according to claim 2, wherein the air conditioner is configured to supply the electric power to both the motor for use and the electric heater. 5. The vehicle air conditioner according to claim 1, wherein the electric heater is an anti-fog heater for heating a window glass for a vehicle. 6. The inverter device is configured to generate a multi-phase AC output, a plurality of electric heaters to which the inter-phase voltage of the multi-phase AC output by the inverter device is applied, and each of the electric heaters The vehicle air conditioner according to any one of claims 1 to 5, further comprising a plurality of corresponding switch means.