JPH06255346A - Electric vehicle - Google Patents

Abstract

PURPOSE:To prevent the useless consumption of a battery due to the excessive cooling and improve the traveling distance per charge by constituting a first coolant circuit for the flow of the low temperature gas liquid coolant in an electric motor and a second coolant circuit for the flow of the vaporized coolant after the car room inside cooling and selecting the coolant circuit according to the heat generation quantity of the electric motor. CONSTITUTION:If the calorific heat of an electric motor 6 is small and the cooling load is small in the cooling mode of an electric automobile, cooling is performed by sending the vapor coolant in the high temperature/high pressure state which is compressed by a compressor 1 to a car room outside heat exchanger 4 through a four-way valve 3, and the coolant is evaporated. The electric motor 6 is cooled by sending vapor coolant returned into the compressor to the electric motor 6. When the cooling load of the electric motor is large, the liquid coolant cooled by the car room outside heat exchanger 4 is sent to both the electric motor 6 and a car room inside heat exchanger 5 through a check valve 8a. The coolant sent into the electric motor 6 is decompressed by an expansion valve 7b and formed to the low temperature gas liquid coolant, and is allowed to flow in the electric motor 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric vehicle that is pollution-free and can efficiently and freely carry people or cargo.

[0002]

2. Description of the Related Art Electric vehicles have been attracting attention as a solution to the problems of greenhouse effect and air pollution caused by the concentration of carbon dioxide in the atmosphere by the exhaust gas from current internal combustion engines. However, the maximum speed of an electric vehicle is lower than that of an internal combustion engine vehicle, and the traveling distance per charge is not sufficient due to the problems of the efficiency of the electric motor or the electric capacity of the battery. In addition, the heat generation of the electric motor and the electric motor increases with the amount of current flowing through the electric motor, and the temperature rises. When the abnormal temperature rises, the electric motor may be damaged. In addition, cooling of the electric motor is a particularly important issue because the efficiency of the electric motor is reduced due to demagnetization of the magnet due to heat generation of the electric motor.

In order to solve the above problems, the electric motor is installed in the refrigeration cycle of the air conditioner for automobiles, and in the summer cooling mode, the low-temperature gas-liquid refrigerant is constantly flowed inside the electric motor in parallel with the indoor heat exchanger to directly generate heat. A method has been proposed in which the cooling is carried out, or a copper pipe or the like is provided around the electric motor, and a low-temperature gas-liquid refrigerant is also made to flow therethrough to indirectly perform heat exchange for cooling.

[0004]

However, the amount of heat generated by the electric motor is small and the cooling load is not so large immediately after the start of traveling or when the vehicle is traveling stably with low torque. The temperature after cooling is the outside temperature in summer (about 3
Even if the temperature is around 5 ° C), the reliability of the electric motor is sufficiently ensured. Therefore, constantly flowing the low-temperature gas-liquid refrigerant is overcooling, and this excess is the compression that drives the compressor in the refrigeration cycle. Power consumption of the machine electric motor, that is, battery power is merely wasted.

[0005]

SUMMARY OF THE INVENTION The present invention solves this drawback by providing an electric motor as a drive source in an electric vehicle in which the electric motor is installed in a refrigeration cycle of an air conditioner of the vehicle. A first refrigerant circuit for flowing a liquid refrigerant and a second refrigerant circuit for flowing an evaporated refrigerant after cooling the vehicle interior of the electric motor are configured, and the first refrigerant circuit and the second refrigerant circuit are generated according to the amount of heat generated by the electric motor. It is achieved by switching.

[0006]

1 is a first refrigerant circuit of a refrigerating cycle of an electric vehicle according to the present invention in a cooling mode. When the amount of heat generated by the electric motor 6 is small and the cooling load is small, for example, when a small torque is required at the time of starting traveling or stable traveling at low speed, the steam in a high temperature and high pressure state after being compressed by the compressor 1 and separated by the oil separator 2 The refrigerant is sent to the exterior heat exchanger 4 via the four-way valve 3 to be cooled. The cooled low-temperature high-pressure liquid refrigerant is first sent to the vehicle interior heat exchanger 5 through the check valve 8a and is decompressed by the expansion valve 7a to become a low-temperature gas-liquid refrigerant, which cools the indoor air and evaporates. Since the size of the indoor heat exchanger 5 of the automobile air conditioner is limited due to the installation space, it is generally necessary to set the evaporation temperature low and increase the temperature difference from the room air to be cooled. Therefore, it is appropriate that the refrigerant evaporation temperature is -10 to -15 ° C, and if the heating degree is 5 to 10 ° C, the refrigerant temperature of the suction vapor returned to the compressor will be 0 to -10 ° C, which is higher than the outside air temperature. It is a fairly low temperature. Therefore, by sending this vapor refrigerant to the electric motor 6 through the three-way valve 9a, the bypass passage 10 and the three-way valve 9b in sequence, a small cooling load of the electric motor 6 is cooled, and an abnormal temperature rise of the electric motor 6 can be prevented.
Here, the solenoid valve 11 is in a closed state. The vapor refrigerant whose temperature has risen due to heat exchange in the electric motor 6 is returned to the compressor 1 via the accumulator 12.

FIG. 2 shows a second refrigerant circuit of the refrigeration cycle in the cooling mode of the electric vehicle of the present invention. When a large amount of heat is generated by the electric motor 6 and a large cooling load is required, for example, when a large torque is required at the time of sudden acceleration, traveling uphill or traveling at high speed,
The high-temperature high-pressure vapor refrigerant that has been compressed by the compressor 1 and separated by the oil separator 2 is sent to the exterior heat exchanger 4 via the four-way valve 3 to be cooled. The cooled low-temperature high-pressure liquid refrigerant is sent to both the electric motor 6 and the vehicle interior heat exchanger 5 through the check valve 8a. The refrigerant sent in the direction of the electric motor 6 is decompressed by the expansion valve 7b to become a low temperature gas-liquid refrigerant and flows into the electric motor 6. By flowing the gas-liquid refrigerant in this manner, the large cooling load of the electric motor 6 is sufficiently cooled,
The refrigerant whose temperature has risen passes through the accumulator 12 and the compressor 1
Return to. Here, the bypass flow passage 10 includes three-way valves 9a and 9a.
It is closed by b, and the solenoid valve 11 is in an open state. In addition, instead of using the three-way valves 9a and 9b, the same effect can be obtained by disposing an electromagnetic valve in the bypass passage 10. Since the heat generation of the electric motor 6 can be completely absorbed by the refrigerant by the above-described action, the abnormal temperature rise of the electric motor 6 can be prevented, and the risk of thermal damage is eliminated. On the other hand, the refrigerant sent in the direction of the heat exchanger 5 in the vehicle interior is expanded by the expansion valve 7a.
Is squeezed to become a low-temperature gas-liquid refrigerant, cools a cooling load in the room and evaporates, and the vapor refrigerant is returned to the compressor 1 through the four-way valve 3 and the accumulator 12.

FIG. 3 shows a refrigerant circuit of the refrigeration cycle in the heating mode of the electric vehicle of the present invention.

The high-temperature, high-pressure vapor refrigerant that has been compressed by the compressor 1 and separated by the oil separator 2 is sent to the vehicle interior heat exchanger 5 by the four-way valve 3 whose flow path is switched. Here, heat is exchanged with the air in the room to heat the room, and as a result, the refrigerant is cooled to become a liquid refrigerant. At this time, the bypass passage 10 is closed by the three-way valves 9a and 9b. The liquid refrigerant is sent to the electric motor 6 through the check valve 8b. The liquid refrigerant is decompressed by the expansion valve 7b and flows to the electric motor 6 through the electromagnetic valve 11 in the open state, and after cooling the electric motor 6, is returned to the compressor 1 through the three-way valve 9b and the accumulator 12. Since the cooling load of the electric motor 6 in winter is small, the liquid refrigerant that cannot be evaporated by the electric motor 6 out of the refrigerant required for indoor heating is sent to the vehicle exterior heat exchanger 4 and decompressed by the expansion valve 7c. The low-temperature gas-liquid refrigerant evaporates by heat exchange with the outside air and is returned to the compressor 1 through the four-way valve 3 and the accumulator 12.

By configuring the above-mentioned refrigerant circuit in the refrigeration cycle of the automobile air conditioner as described above, the refrigeration cycle can be operated according to the cooling load of the electric motor for driving the electric vehicle, and the battery due to overcooling can be operated. Since it is possible to avoid wasteful consumption, it is possible to construct an electric vehicle with improved traveling distance per charge and overall high energy efficiency.

[0011]

As described above, the present invention is an electric vehicle in which an electric motor is used as a driving source and the electric motor is installed in a refrigeration cycle of an air conditioner of a vehicle. A second refrigerant circuit that flows an evaporative refrigerant after cooling the vehicle interior to the circuit and the electric motor, and switches the first refrigerant circuit and the second refrigerant circuit in accordance with the amount of heat generated by the electric motor, thereby an electric vehicle It is possible to operate the refrigeration cycle according to the cooling load of the electric motor for driving, and to avoid wasteful consumption of the battery due to overcooling, improving the mileage per charge and overall energy-efficient electricity It can be a car.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a first refrigerant circuit of a refrigeration cycle in a cooling mode of an electric vehicle of the present invention.

FIG. 2 is an explanatory diagram of a second refrigerant circuit of a refrigeration cycle in a cooling mode of the electric vehicle of the present invention.

FIG. 3 is an explanatory diagram of a refrigeration cycle in a heating mode of the electric vehicle of the present invention.

[Explanation of symbols]

 1 compressor 2 oil separator 3 four-way valve 4 vehicle exterior heat exchanger 5 vehicle interior heat exchanger 6 electric motor 7a expansion valve 7b expansion valve 7c expansion valve 8a check valve 8b check valve 9a three-way valve 9b three-way valve 10 bypass flow path 11 Solenoid valve 12 Accumulator

Claims (1)

[Claims] 1. An electric vehicle having an electric motor as a drive source, wherein the electric motor is installed in a refrigeration cycle of an air conditioner of an automobile, and a first refrigerant circuit for flowing a low-temperature gas-liquid refrigerant to the electric motor and a vehicle interior cooling to the electric motor. The electric vehicle, characterized in that a second refrigerant circuit is made to flow the evaporating refrigerant after performing the above step, and the first refrigerant circuit and the second refrigerant circuit are switched according to the amount of heat generated by the electric motor.