JP2604688Y2 - Automotive air conditioners - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a vehicle air conditioner suitable for an electric vehicle or the like having no hot water heating source for air conditioning, and more particularly to a vehicle in which an overload on a compressor driving motor at the time of starting the compressor is eliminated. For air conditioners.

[0002]

2. Description of the Related Art Recently, in view of the impact on the global environment,
BACKGROUND ART Electric vehicles have attracted attention, and in these electric vehicles, a battery-driven electric motor is used as a driving source.

This electric vehicle is different from a general gasoline-powered vehicle in that the heat of an engine, which is a driving source for driving, is used as a heat source to perform air conditioning in a passenger compartment. Therefore, when air conditioning inside the vehicle cabin is performed using this heat, the cooling performed by driving the compressor with the electric motor can easily achieve the predetermined capacity, even if the specified capacity is obtained relatively easily. Heating using heat is difficult to obtain a predetermined capacity.

Therefore, it has been considered that the air conditioning in the passenger compartment of an electric vehicle is performed using a so-called heat pump type air conditioner that does not use the heat of a traveling drive source. When this heat pump type air conditioner is used, even when heating the interior of the vehicle, the heat obtained by circulating the refrigerant is used without using the heat of the electric motor as a heat source, so it is relatively easy. A high temperature heat source,
Practical heating becomes possible.

FIG. 5 is a schematic diagram showing an example of a heat pump type air conditioner mounted on an electric vehicle. This heat pump type air conditioner has a ventilation duct 2 for sending air taken in by a blower 1 toward a vehicle interior.
As the heat exchanger, an evaporator 3 and a first condenser 4 mainly working during the heating operation are arranged in the ventilation duct 2 in order from the upstream side, and the cooling operation is mainly performed outside the ventilation duct 2. A sometimes working second capacitor 5 is provided.
The heat cycle is configured by connecting a compressor 6, a second condenser 5, a first condenser 4, a liquid tank 7, an expansion valve 8, and an evaporator 3 by piping.
In addition, a three-way valve 9 is provided at the inlet of the second condenser 5 to switch between the condensers 4 and 5 functioning during the heating operation and the cooling operation, and is directly connected to the outlet of the second condenser 5 by the bypass pipe 10. I have.

During the cooling operation, the compressor 6 is driven by the drive motor 20 via the belt 21 for transmitting power, and the refrigerant discharged from the compressor 6 is guided to the second condenser 5 by the three-way valve 9. Then, it flows through the first condenser 4, the liquid tank 7, the expansion valve 8, and the evaporator 3 and is sucked into the compressor 6 again. In this process, the evaporator 3 cools the intake air by evaporating the liquid refrigerant by heat exchange, and the second condenser 5 discharges the heat taken by the evaporator 3 to the outside to cool the gaseous refrigerant and condense and liquefy it. Therefore, at this time, the first condenser 4 does not work as a heat exchanger. On the other hand, during the heating operation, the three-way valve 9 is switched, and the refrigerant discharged from the compressor 6 is immediately led to the first condenser 4 via the bypass pipe 10. Thereby, the gaseous refrigerant from the compressor 6 is condensed and liquefied by heat exchange in the first condenser 4, and the air cooled by the evaporator 3 is heated. Therefore, dehumidification heating is realized. In addition, the temperature of the air blown into the vehicle interior is adjusted by adjusting the opening of the air mix door 11 disposed upstream of the first condenser 4.

[0007]

As described above, the heat pump type air conditioner uses the latent heat of the refrigerant to heat the air even during heating. However, the heat pump type air conditioner uses a traveling drive source such as a gasoline vehicle. The cooling water (warm water) of a certain engine cannot be used as a heat source. Normally, the heating operation is performed because the outside air temperature is low as well as the temperature in the vehicle compartment.When the outside air temperature is low in this manner, the temperature of the refrigerant is also low. The amount of heat required for heating cannot be secured, and sufficient heating operation cannot be performed. Therefore, an auxiliary heater for heating at a low temperature is required. Also, when the compressor is started, the oil temperature inside the compressor is low, so that the viscosity of the oil becomes high and a large load is generated on the compressor drive motor. Therefore, a large torque is required for the compressor drive motor. . If a sufficient driving torque cannot be obtained, the motor may be burned if the compressor is not driven and the driving motor does not rotate and the current continues to flow through the coil.

Accordingly, the present invention has been made in view of such problems of the prior art, and is a heat pump suitable for an electric vehicle or the like in which a load applied to a compressor driving motor is reduced at the time of startup in a low outside air temperature state. It is an object of the present invention to provide an automotive air conditioner of the type.

[0009]

According to the present invention, there is provided a ventilation duct for sending air taken in by a blower toward a vehicle interior, an evaporator provided in the ventilation duct, and It has a first condenser disposed downstream of the evaporator in the ventilation duct, and a second condenser disposed outside the ventilation duct and connected to the first condenser, and is driven by a compressor driving motor. A refrigerant circuit for heating operation that guides the refrigerant discharged from the compressor through the bypass passage to the first condenser by a circuit switching valve, and a refrigerant circuit for cooling operation that guides the refrigerant to the second condenser by the circuit switching valve. An air conditioner for a vehicle, comprising: an inside of the compressor for detecting an oil temperature inside the compressor. And Le temperature sensor, wherein a refrigerant temperature sensor for detecting the refrigerant temperature inside the compressor, the <br/>, an electric heater provided in the oil reservoir of the internal the compressor, the oil temperature sensor Yo
If the detected oil temperature is below the specified oil temperature
In addition, the electric heater
Oil, the oil temperature becomes the predetermined oil temperature
Warmed up, and also detected by the refrigerant temperature sensor
When the refrigerant temperature is equal to or lower than a predetermined refrigerant temperature, the electric heating
The oil inside the compressor by the
An air conditioner for a vehicle, wherein the temperature is increased until the temperature reaches the predetermined refrigerant temperature .

[0010]

In the present invention constructed as described above, when the compressor is started, the oil temperature sensor detects the oil temperature inside the compressor, and when the oil temperature is low and the viscosity is high, the oil is collected in the oil pool inside the compressor. The provided electric heater is operated to warm the oil and reduce its viscosity. As a result, when starting the compressor,
Since the viscosity of the oil is low, a large load is not applied to the motor for driving the compressor. Also,
When the heating operation is performed, the refrigerant discharged from the compressor by the circuit switching valve is guided to the first condenser via the bypass passage, and the first condenser functions as a heat exchanger. At this time, a refrigerant temperature sensor provided inside the compressor detects the temperature of the refrigerant in the compressor,
When the temperature of the refrigerant is low and the amount of heat required for heating cannot be secured, an electric heater provided in an oil sump inside the compressor is operated to warm the refrigerant, thereby supplying the refrigerant with the amount of heat required for heating.

Therefore, when the outside air temperature is low, the heating operation can be efficiently performed from the beginning at the time of startup.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing an embodiment of the present invention. In FIG. 1, members common to those in FIG. 5 are denoted by the same reference numerals.

The air conditioner for a vehicle shown in FIG. 1 is a heat pump type air conditioner mounted on an electric vehicle. Like the heat pump type air conditioner shown in FIG. It has a ventilation duct 2 for sending air toward it, and in this ventilation duct 2, an evaporator 3 and a first condenser 4 are arranged in order from the upstream side as a heat exchanger. A second condenser 5 is provided outside the ventilation duct 2 as another heat exchanger. As described later, the first condenser 4 mainly operates during the heating operation, and the second condenser 5 mainly operates during the cooling operation. The evaporator 3, the first condenser 4 and the second condenser 5 are connected to a liquid tank 7 and an expansion valve 8 by piping.
Together with the compressor 6 to form a heat cycle. Further, a three-way valve 9 as a circuit switching valve is provided at an inlet of the second condenser 5, and is directly connected to an outlet of the second condenser 5 by a bypass pipe 10 forming a bypass passage. The three-way valve 9 guides the refrigerant discharged from the compressor 6 through the bypass pipe 10 to the first condenser 4 immediately, and then circulates the liquid tank 7, the expansion valve 8, the evaporator 3, and the compressor 6 for heating operation. Circuit and the refrigerant discharged from the compressor 6 to the second condenser 5 and then to the first
The condenser 4, the liquid tank 7, the expansion valve 8, the evaporator 3, and the refrigerant circuit for cooling operation circulated to the compressor 6 are switched. The blower 1 includes a fan and a fan motor for driving the fan. The compressor 6 is driven by a compressor drive motor 20 via a belt 21. In the case of an electric vehicle, the driving of the electric vehicle and the driving of the compressor 6 are performed by using an electric motor, which is a driving source for driving the electric vehicle, as a motor for driving the compressor, instead of a dedicated motor for driving the compressor. It is driven by a battery (not shown). In this embodiment, the case where there is a dedicated compressor driving motor is shown.

The compressor 6 used in the present embodiment is a rotary type compressor, as shown in FIG.
As shown in FIG. 1, a compression section 62 is provided in a closed casing 61. The compression portion 62 is formed by sandwiching the cylinder 63 between the front side block 64 and the rear side block 65 and tightening the cylinder with a fastening bolt (not shown).

[0015] As shown in FIG.
The rotor portion 66 is housed in the rotor 3a. The rotor portion 66 has a rotor body 67 and a slide vane 68. Have been. Rotor body 6
7, five vane grooves 69 are formed radially, and a slide vane 68 is slidably provided in the vane grooves 69. When the rotor unit 66 is rotated via a shaft 70 by a drive source (not shown), the slide vanes 68 protrude from the vane grooves 69 by centrifugal force or the like,
It slides along the inner peripheral surface of the bore 63a.

Accordingly, in the compression section 62, the refrigerant flowing from the inlet 71 of the casing 61 passes through the suction port 72 opened in the front side block 64 and is compressed in the compression chamber C. The compression chamber C includes slide vanes 68,
A partition is formed between the contact points or the slide vanes and the inner peripheral surface of the bore 63a. Since the volume of the compression chamber C changes with the rotation of the rotor section 66, the refrigerant sealed therein is compressed and discharged from a discharge port 73 opened in the cylinder 63 against a discharge valve 74. It enters the high pressure chamber 76 through the passage 75. Since the oil separator 77 is provided at the outlet of the communication passage 75, the oil contained in the refrigerant is separated by the oil separator 77, and the separated refrigerant flows out from the outlet 78 to the outside. The separated oil returns to the oil sump 80, passes through the oil passage 81, and lubricates the operation of the rotor unit 66.

A refrigerant outlet 78 is provided inside the compressor.
A refrigerant temperature sensor 17 for detecting the temperature of the refrigerant in the vicinity
Is provided, an oil temperature sensor 16 for detecting the temperature of the refrigerant during operation and detecting the oil temperature.
Is provided to detect the oil temperature when the compressor is started. Further, the oil reservoir 80 is provided with a PTC heater 15 as an electric heater for warming the oil. The temperature sensors 16 and 17 may be of any type, for example, capable of taking out the detected temperature as an electric signal, such as a thermistor, a bimetal switch, a pressure sensor (strain gauge), and a resistance value of a PTC heater. Is suitable as a temperature sensor.

Since the PTC heater itself is a well-known technique, its detailed description is omitted, but the PTC heater generally has superior performance, safety and reliability as compared with a normal resistance heater. For example, the PTC heater 15 has a structure in which a PTC ceramic called a PTC element is sandwiched between honeycomb fins sandwiched on both sides by metal plates, and a plurality of these are connected in parallel. A negative (-) terminal and a positive (+) terminal are connected to both ends of the PTC heater 15, respectively, and when power is supplied from a power source such as a battery through these terminals, each PTC element generates heat.

When the outside air temperature or the refrigerant temperature is low and the oil temperature is lower than a predetermined temperature, by energizing the PTC heater 15, the oil in the compressor is warmed and its viscosity is reduced.

Next, the operation of the present apparatus having the above-described configuration is such that, in the heating operation, the refrigerant discharged from the compressor 6 is guided to the first condenser 4 via the bypass pipe 10 immediately. Switch valve 9. The flow of the refrigerant at this time is as shown by a solid line in FIG.
The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 6 is guided by the three-way valve 9 through the bypass pipe 10 to the first condenser 4, where it releases heat to the intake air to become a medium-temperature and high-pressure liquid refrigerant. Thereby, the evaporator 3
The air cooled in is heated. Other operations of the heat cycle are the same as those in the cooling operation described above. Therefore, the air taken in by the blower 1 is heated by the first condenser 4 after being cooled and dehumidified by the evaporator 3. That is, dehumidification heating is realized.

The temperature of the air blown into the passenger compartment is controlled by adjusting the opening of the air mixing door 11 to change the mixing ratio of the cool air passing through the evaporator 3 and the hot air passing through the first condenser 4. Will be

In this embodiment, when the compressor is started, the oil temperature sensor 16 detects the oil temperature. When the oil temperature is low and the oil viscosity is high, the PTC heater 15 is energized. Warm the oil and reduce the viscosity of the oil before starting the compressor. To do this, first, the oil temperature sensor 16 detects whether or not a predetermined oil temperature has been reached,
When the oil temperature is low, power is supplied to the PTC heater 15,
Warm the oil to a temperature at which the viscosity of the oil at startup does not place a large load on the drive motor.

If the heating performance is insufficient, the PTC heater 15 is energized to make up for the insufficient heating performance. That is, when the refrigerant temperature sensor detects a lower temperature as the amount of heat of the refrigerant required for heating is insufficient, the PTC heater 15 provided in the oil sump 80 is operated to warm the oil. Accordingly, when the refrigerant is compressed in the compression section 62, the refrigerant mixes with the oil, so that the heat of the heated oil is supplied to the refrigerant. And the refrigerant | coolant which has the calorie | heat amount required for heating will be sent to the 1st condenser 4 as mentioned above, and will raise the temperature of the taken-in air.

The above operation flow will be described with reference to the flowchart shown in FIG.

First, a switch for heating is turned on (S1), and an oil sump 80 is detected by the oil temperature sensor 16.
The oil temperature To in the inside is detected (S2). At this time, if it is detected that the oil temperature has not reached the predetermined oil temperature Tox (S3), power is supplied to the PTC heater 15 to warm the oil (S4). Thereafter, the power supply to the PTC heater 15 is continued until the oil temperature rises and reaches the predetermined oil temperature, and the oil temperature rises and reaches the predetermined oil temperature. If detected (S3), the PTC heater 15
Is stopped (S5), and the compressor 6 is started (S6).

When the compressor 6 is started and the refrigerant moves during the heat cycle, the refrigerant temperature sensor 17 provided near the refrigerant outlet of the compressor 6 detects the refrigerant temperature T.
detecting the r (S7), the temperature of the refrigerant given cold necessary heating
If it is detected that the medium temperature Tr x has not been reached (S
8), energize the PTC heater 15 to warm the oil (S
9). This indirectly heats the refrigerant. Thereafter, the power supply to the PTC heater 15 is continued until it is detected that the refrigerant temperature rises and reaches a temperature necessary for heating, and it is detected that the refrigerant temperature rises and reaches a temperature necessary for heating. Then, the power supply to the PTC heater 15 is stopped (S10), the blower 1 is operated, and the heating operation is started (S11).

As described above, in the present embodiment, the blower 1 is not operated until the temperature of the refrigerant reaches the temperature (heat amount) required for heating, so that when the switch for the heating operation is turned on. This prevents cold wind from being blown into the passenger compartment.

In this embodiment, the PTC heater 15 is used as the electric heater. However, the present invention is not limited to this, and it is a matter of course that any heater can be used as long as it generates heat when energized.

[0029]

As described above, according to the automotive air conditioner of the present invention, the oil temperature sensor detects the oil temperature inside the compressor, and when the oil temperature is low and the viscosity is high, the oil temperature inside the compressor is reduced . By activating the electric heater provided in the oil reservoir to warm the oil and reduce its viscosity, a large load is not applied to the compressor drive motor, and a smaller compressor drive motor can be used. Becomes

Further, the refrigerant temperature sensor detects the temperature of the refrigerant in the compressor, and operates the electric heater even when the temperature of the refrigerant is low and the amount of heat required for heating cannot be secured.
By heating the refrigerant, the amount of heat required for heating can be supplied to the refrigerant, so that a sufficient heating operation can be performed from the beginning at the time of startup.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sectional view of a compressor used in the embodiment.

FIG. 3 is a sectional view taken along the line 5-5 in FIG. 2;

FIG. 4 is a flowchart illustrating an operation of the apparatus according to the embodiment.

FIG. 5 is a schematic configuration diagram illustrating an example of a conventional heat pump type air conditioner.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Blower 2 ... Ventilation duct 3 ... Evaporator 4 ... 1st condenser 5 ... 2nd condenser 6 ... Compressor 9 ... 3 way valve (circuit switching valve) 10 ... Bypass pipe (bypass passage) 15 ... PTC heater (electric heating heater) 16: Oil temperature sensor, 17: Refrigerant temperature sensor.

Claims (1)

(57) [Scope of request for utility model registration] An air duct (2) for sending air taken in by a blower (1) toward a vehicle interior, an evaporator (3) disposed in the air duct (2), and the air duct. (2) a first condenser (4) disposed downstream of the evaporator (3), and a second condenser disposed outside the ventilation duct (2) and connected to the first condenser (4). The refrigerant discharged from the compressor (6) driven by the compressor driving motor (20) is supplied to the first refrigerant through a bypass passage (10) by a circuit switching valve (9).
An air conditioner for a vehicle, comprising: a refrigerant circuit for heating operation guided to a condenser (4); and a refrigerant circuit for cooling operation guided to the second condenser (5) by the circuit switching valve (9). Inside the compressor (6), an oil temperature sensor (16) for detecting the oil temperature inside the compressor (6)
A refrigerant temperature sensor (17) for detecting the refrigerant temperature inside the compressor (6), and the compressor (6)
Electric heater provided inside the oil sump (80) (1
5), it has an oil temperature detected by the oil temperature sensor (16)
When the temperature is below the specified oil temperature (Tox), the electric heating
The oil inside the compressor by the
Warm until the oil temperature reaches the predetermined oil temperature (Tox).
And the refrigerant temperature detected by the refrigerant temperature sensor (17).
When the medium temperature is equal to or lower than a predetermined refrigerant temperature (Trx), the electric heating is performed.
The oil inside the compressor is heated by a heat heater (15),
Warm until the refrigerant temperature reaches the predetermined refrigerant temperature (Trx)
Automotive air conditioning system, characterized in that that.