JP4104780B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle air conditioner that enables cooling for a predetermined time without driving a compressor when the engine is stopped in a vehicle equipped with an idle stop control system that stops the engine (engine) during so-called idling.
[0002]
[Prior art]
Conventionally, from the viewpoint of environmental protection, a so-called idle stop vehicle has been proposed that improves fuel efficiency by stopping the engine during idling. Since this vehicle stops the engine when the running vehicle stops, the vehicle air conditioner mounted on the vehicle is also stopped.
[0003]
For this reason, for example, if the engine is stopped during the cooling operation, the cooling operation is also stopped, the temperature in the passenger compartment is increased, and the driver and the passenger are uncomfortable.
[0004]
Therefore, in order to avoid this, there has been proposed a vehicle air conditioner including a so-called hybrid compressor that temporarily drives a compressor by a battery alone and continues cooling operation.
[0005]
[Problems to be solved by the invention]
However, in such a conventional technique, in an idle stop vehicle that frequently starts and stops the engine, the starting torque of the compressor is very large, so the power consumption of the motor for driving the compressor is very large, and the load on the battery is also great. Since it is large, it is a big problem in practical use. Further, since the vehicle air conditioner requires a motor for driving the compressor and a control means for controlling the drive, there is a problem that the number of parts is large and the cost is high.
[0006]
The present invention has been made in view of the above-described problems of the prior art, and in a vehicle air conditioner for an idle stop vehicle, the residual refrigerant is used even if the engine is stopped without driving the motor of the compressor. It is an object of the present invention to provide a vehicle air conditioner that can suppress a sudden rise in the passenger compartment temperature due to a cooling action.
[0007]
[Means for Solving the Problems]
According to the first aspect of the present invention, an engine that generates driving force for a vehicle, a compressor that is driven by the engine and pressurizes and supplies refrigerant to the air conditioner, the compressor, refrigerant condensing means, a liquid tank, and refrigerant expansion In a vehicle air conditioner comprising: a refrigeration cycle comprising a means, a refrigerant evaporating means and a pipe for sending the refrigerant, and an idle stop control means for outputting an engine stop command to the engine at idling, The refrigeration cycle is provided in the middle of a refrigerant pipe that connects the compressor and the refrigerant condensing means, and includes a check valve that allows only the flow from the compressor to the refrigerant condensing means, and an orifice that bypasses the refrigerant expansion means. Provided in the orifice tube branch section between the tube and the liquid tank and the refrigerant expansion means to switch the refrigerant flow path. Switching means, and when an engine stop signal based on idle stop control is input from the idle stop control means, a signal for switching the refrigerant flow path from the normal refrigerant piping to the orifice tube side is output to the switching means. set only the switching control means for said refrigerant remaining amount detecting means for detecting the refrigerant remaining in the liquid tank is provided, the orifice tube, the refrigerant flow path according to the refrigerant remaining amount detected by the refrigerant level detecting means A variable orifice tube for adjusting the throttle is provided, and a cooling possible time calculating means for calculating a cooling possible time based on the refrigerant remaining amount detected by the refrigerant remaining amount detecting means is provided, and the idle stop control means is provided with the cooling possible time. characterized in that the cooling time information by calculating means is a means for setting the idle stop time To [0011]
[Action and effect of the invention]
In the first aspect of the invention, even if the engine is stopped by the idle stop control means and the driving of the compressor driven by the engine is stopped, the check valve and It is possible to hold the high-pressure refrigerant in the liquid tank between the orifice tubes for a certain period of time. Thereby, even if the driving of the compressor is stopped, the refrigerant can be gradually supplied from the orifice tube to the refrigerant evaporating means, and a rapid increase in the temperature in the passenger compartment can be suppressed.
[0012]
In addition, by providing a variable orifice tube that adjusts the flow rate of the orifice tube according to the remaining amount of refrigerant, even if the refrigerant pressure changes due to a change in the remaining amount of refrigerant, the flow rate of the orifice tube can be adjusted to maintain a constant refrigerant flow rate. Can be supplied, and stable air conditioning can be performed even during idle stop.
[0013]
In addition, when calculating the idle stop time in the idle stop control means, it is possible to perform idle stop efficiently by calculating based on the signal from the air conditioning possible time calculation means, thereby improving fuel efficiency. I can do it.
[0015]
Embodiment
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0016]
(Embodiment 1)
FIG. 2 is an overall system diagram in the refrigeration cycle of the vehicle air conditioner according to the present invention.
[0017]
First, the configuration will be described. A vehicle (not shown) is driven by the engine 1 and the compressor 3 is driven via the V-belt 2. The refrigerant pressurized by the compressor 3 air-conditions the vehicle in a refrigeration cycle constituted by the condenser 4, the expansion valve 5 and the evaporator 6. Here, the expansion valve 5 used in the present embodiment is opened when the engine is stopped.
[0018]
A check valve 7 is provided between the compressor 3 and the condenser 4 to block the refrigerant flow from the condenser 4 to the compressor 7. A liquid tank 8 and a switching valve 9 are provided between the condenser 4 and the expansion valve 5. The liquid tank 8 stores a refrigerant that can cool for several minutes even when the compressor 3 is stopped.
[0019]
When an idle stop signal is output in the idle stop control control unit 11, this signal is also output to the switching control control unit 12, and the switching valve 9 is provided so as to bypass the refrigerant flow. Switch to orifice tube 10. The orifice tube 10 adiabatically expands the refrigerant stored in the liquid tank 8 to form a low-temperature and low-pressure liquid-gas mixed refrigerant and supplies it to the evaporator 6.
[0020]
Next, the operation will be described. While the compressor 1 is driven by the engine 1 and the air conditioning of the vehicle is being executed, the idle stop control control unit 11 determines that the engine is stopped and outputs an engine stop command to the engine 1. At this time, an engine stop signal is also output to the switching control unit 12. In the switching control control unit 12, when a signal for stopping the engine is input, a switching signal is output to the switching valve 9, and the flow path of the refrigerant is switched to the orifice tube 10 side. At this time, the pipe (liquid tank 8 side) sandwiched between the check valve 7 and the orifice tube 10 is in a state filled with a high-pressure refrigerant. This high-pressure refrigerant is adiabatically expanded by the orifice tube 10 to become a low-temperature and low-pressure liquid-gas mixed refrigerant. By gradually supplying the refrigerant to the evaporator 6, the engine 1 is stopped and the compressor 3 is stopped. However, cooling for a certain time is possible.
[0021]
As described above, by taking the above embodiment, the engine is stopped by the engine stop signal of the idle stop control control unit 12, and the operation of the air-conditioning compressor 3 driven by this engine is stopped. However, it is possible to maintain the cooling for a certain period of time during idling stop without providing auxiliary equipment driving means such as an electric motor for driving the compressor. As a result, it is possible to prevent a sudden rise in the temperature of the passenger compartment even when the engine is stopped, with a simple configuration, without burdening the battery.
[0022]
(Other embodiments)
In the first embodiment, an orifice tube with a fixed throttle is used. However, a variable orifice tube is provided that has a means for detecting the remaining amount of refrigerant in the liquid tank and variably controls the amount of restriction in accordance with the detected remaining amount of refrigerant. May be used. As a result, when the engine is stopped by the idle stop control, it is possible to supply a stable refrigerant that maintains the cooling effect, and it is possible to manage the engine stop time.
[0023]
Furthermore, the capacity of the liquid tank can be increased, and the cooling effect maintenance time due to the remaining amount of refrigerant can be extended.
[Brief description of the drawings]
FIG. 1 is a claim correspondence diagram showing a vehicle air conditioner of the present invention.
FIG. 2 is an overall system diagram showing the vehicle air conditioner according to the first embodiment.
[Explanation of symbols]
1 Engine 2 V Belt 3 Compressor 4 Condenser 5 Expansion Valve 6 Evaporator 7 Check Valve 8 Liquid Tank 9 Switching Valve 10 Orifice Tube 11 Idle Stop Control Control Unit 12 Switching Control Control Unit

Claims (1)

An engine (1) for generating the driving force of the vehicle;
A compressor (2) driven by the engine (1) to pressurize the refrigerant and supply it to the air conditioner;
The compressor (2), the refrigerant condensing means (3), liquid tank (7), the refrigerant expansion means (4), a refrigeration cycle composed piping etc. for Nagareoku refrigerant evaporation means (5) and the refrigerant,
Idle stop control means (10) for outputting an engine stop command to the engine (1) during idling;
In a vehicle air conditioner equipped with
Wherein the refrigeration cycle is provided in the middle of the refrigerant pipes connecting the compressor (2) and the refrigerant condensing means (3), allowing only the flow of the refrigerant condensing means (3) from the compressor (2) check valve (6), an orifice tube (9) provided by bypassing the refrigerant expansion means (4), and an orifice tube branch between the liquid tank (7) and the refrigerant expansion means (4), A switching means (8) for switching the refrigerant flow path is added,
When an engine stop signal based on idle stop control is input from the idle stop control means (10), a signal for switching the refrigerant flow path from the normal refrigerant pipe to the orifice tube (9) side is sent to the switching means (8). setting the switching control means (11) for outputting Te,
Refrigerant remaining amount detecting means for detecting the remaining amount of refrigerant in the liquid tank (7) is provided, and the orifice tube (9) is made to restrict the refrigerant flow path according to the remaining amount of refrigerant detected by the remaining refrigerant amount detecting means. The variable orifice tube to be adjusted
A cooling time calculation unit is provided for calculating a cooling possible time based on the refrigerant remaining amount detected by the refrigerant remaining amount detection unit;
The vehicle air conditioner characterized in that the idle stop control means (10) is a means for setting an idle stop time based on coolable time information by the coolable time calculating means .

Images