JP2003136951A - Cooling device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for a vehicle capable of forming its compressor in a small and light construction while the cooling function when engine is stopped is well secured. SOLUTION: The cooling device for vehicle includes a first compressor 111 located in its refrigerating cycle device 111, a second compressor 122 installed in line with the first compressor 111 for compressing the refrigerant by a motor 121, and a control device 130 to control the operation of the second compressor 122, whereby the second compressor 122 is operated by the control device 130 in case the engine 10 is stopped when the refrigerating cycle device 110 is in operation, wherein the control device 130 operates and stops the second compressor 122 in accordance with the thermal load of the refrigerating cycle device 110 even in case the first compressor 111 is operated by the engine 10.

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 for a so-called idle stop vehicle that stops the engine when the vehicle is temporarily stopped during traveling.

[0002]

2. Description of the Related Art In recent years, there is an example in which a so-called idle stop vehicle is put on the market from the viewpoint of fuel saving. In this vehicle, since the engine is stopped when the vehicle is temporarily stopped during traveling, the compressor in the refrigeration cycle device that operates by receiving the driving force of the engine is stopped together while the engine is stopped. It will not work as a cooling device.

As a solution to this problem, for example, Japanese Patent Laid-Open No. 2000-
In the 127753 publication, a second compressor driven by a motor is provided so as to be arranged in parallel with the compressor,
When the engine is stopped, the cooling device is operated by the second compressor so that the cooling function is performed regardless of whether the engine is operated or stopped.

[0004]

However, the technique of the above publication adds a second compressor that is operated when the engine is stopped, and uses the compressor and the second compressor separately when the engine is driven and stopped. Since the compressors are operated in such a manner, the capacity and size of each compressor are determined so as to match the maximum heat load of the cooling device.
Especially for a compressor driven by an engine,
For example, during rapid cooling (during cooldown) immediately after starting in summer
Is the maximum heat load, and the capacity and physique are set accordingly, which in turn causes the compressor to become larger.

In view of the above problems, it is an object of the present invention to provide a vehicle air conditioner capable of reducing the size and weight of a compressor while ensuring a cooling function when the engine is stopped.

[0006]

The present invention employs the following technical means in order to achieve the above object.

According to the first aspect of the present invention, the invention is applied to a vehicle in which the engine (10) is stopped when the vehicle is temporarily stopped during traveling, and is operated by receiving the driving force of the engine (10). The refrigerant is compressed by the first compressor (111), and is then arranged in parallel with the first compressor (111) in the refrigeration cycle device (110) that cools the air by condensing, expanding, and evaporating. And a motor (121)
Compressor (122) for compressing the refrigerant by driving the
And a control device (130) for controlling the operation of the second compressor (122).
0) When the engine (10) is stopped during operation, in the vehicle air-conditioning system in which the second compressor (122) is operated by the control device (130), the control device (130) is the first by the engine (10). It is characterized in that the second compressor (122) is operated and stopped according to the heat load of the refrigeration cycle apparatus (110) even when the compressor (111) is operating.

As a result, the compressor (11
In addition to 1), the second compressor (122) is operated at the same time, so that the discharge flow rate of the refrigerant can be increased and the cooling capacity can be improved compared to when the compressor (111) alone operates. Therefore, the compressor (111) can be reduced in size and weight due to the increased cooling capacity. still,
When the engine (10) is stopped, the second compressor (12
By the operation of 0), the cooling function can be continued.

According to the second aspect of the present invention, the heat load of the refrigeration cycle apparatus (110) is represented by the difference (ΔT) between the cooling temperature (Tr) at a predetermined portion and the set temperature (Tset) set by the occupant. The second compressor (122) is operated when the temperature difference (ΔT) is equal to or greater than a predetermined value (ΔT1), and is stopped when the temperature difference (ΔT) is less than the predetermined value (ΔT1). Is characterized by.

Accordingly, the refrigeration cycle device (1
By utilizing the temperature signal used for the control of 10), the control of the second compressor (120) combined use can be easily coped with.

Specifically, as in the third aspect of the present invention, it is preferable that the cooling temperature (Tr) at the predetermined portion is the vehicle compartment temperature (Tr), whereby the second compressor is provided. The timing when (120) should be operated together is clarified, and for example, it can be effectively used for dealing with a cooldown in the summer.

The reference numerals in parentheses of the above-mentioned means indicate the correspondence with the concrete means described in the embodiments to be described later.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the present invention is shown in FIGS. 1 to 4, and first, a specific configuration will be described with reference to FIG.

The vehicle cooling device 100 is applied to a so-called idle stop vehicle in which the engine 10 is stopped when the vehicle is temporarily stopped during traveling, and includes a refrigeration cycle device 110 and a control device 130.

The refrigeration cycle device 110 forms a well-known refrigeration cycle, and here, two compressors,
That is, the first compressor 111 and the second compressor 122 are arranged. In the present invention, as will be described later, depending on the heat load of the refrigeration cycle device 110, the first compressor 11
The first compressor 111 and the second compressor 122 are operated together, and the capacity and physique of the first compressor 111 are set in advance as being smaller than the capacity and physique required at the time of maximum heat load in a single state. ing.

This refrigeration cycle apparatus 110 comprises a first compressor 111 for compressing the refrigerant in the refrigeration cycle to high temperature and high pressure.
A condenser 112 that condenses and liquefies the compressed refrigerant, an expansion valve 113 that adiabatically expands the liquefied refrigerant, an evaporator 114 that evaporates the expanded refrigerant and cools the air passing therethrough by the latent heat of evaporation of the refrigerant, and a refrigerant pipe 115. Are sequentially connected to form a closed circuit.

The first compressor 111 is operated via a pulley and a pulley belt using the vehicle running engine 10 as a drive source, and is turned ON-O by the controller 130.
It is FF controlled. Further, the evaporator 114 includes a blower 11
4b is provided so that the air cooled by the evaporator 114 is blown into the vehicle interior, and the blowing amount is controlled by the control device 130. Further, on the downstream side of the evaporator 114 in the air flow, an evaporator temperature sensor 114 for detecting the cooled air temperature (evaporator rear air temperature Te).
a is provided.

The second compressor 122 is arranged in parallel with the first compressor 111, specifically, between the inflow side of the condenser 112 and the outflow side of the evaporator 114. And are connected by the refrigerant pipe 123.
The second compressor 122 operates using a motor 121, which is operated by a battery 140 as a power source, as a drive source, and constitutes the electric compressor 120 together with the motor 121. The second compressor 122 is basically driven by the controller 130 when the engine 10 is stopped and the first compressor 111 is stopped. (Details will be Described Later) Next, the configuration of the control device 130, which is a main part of the present invention, will be described. In addition to the operation of the first compressor 111 and the blower 114b, the control device 130 includes the electric compressor 120,
That is, the operation of the second compressor 122 is controlled.
The controller 130 includes the evaporator temperature sensor 11 described above.
4a and signals from various sensors (not shown) and switches operated by the occupant, that is, vehicle speed, engine speed, idle stop determination, A / C request, set temperature Tset set by the occupant, and inside air temperature (vehicle interior Temperature) T
Signals such as r and the outside air temperature are input.

When the engine 10 is driven while the vehicle is running and the A / C request signal is input, the first
The compressor 111 is operated (ON). Then, when the evaporator rear air temperature Te falls below a predetermined value, the first compressor is turned on.
FF. Further, the amount of air blown by the blower 114b is varied according to the set temperature Tset set by the occupant and the target outlet temperature TAO calculated from various temperature signals and the like. Further, the motor 121 is driven and the second compressor 122 is operated by the idle stop determination signal when the engine 10 is stopped.

Further, in the present invention, the refrigeration cycle apparatus 110
According to the heat load of the first compressor 1 by the engine 10.
Even when 11 is in operation, the second compressor 122 is operated together. Here, the heat load is taken as a difference ΔT between a vehicle compartment temperature Tr as a cooling temperature at a predetermined portion and a set temperature Tset set by an occupant, and by comparing this temperature difference ΔT with a predetermined value ΔT1,
The second compressor 122 is turned on and off. More specifically, the second compressor 122 is operated when the temperature difference ΔT is equal to or larger than the predetermined value ΔT1, and the second compressor 122 is stopped when the temperature difference ΔT is below the predetermined value ΔT1. .

Next, the operation based on the above configuration will be described in detail with reference to the flow charts shown in FIGS. 2 and 3 and the time chart shown in FIG. First, the basic control of the refrigeration cycle apparatus 110 by the control device 130 will be described using the flowchart shown in FIG.

First, when the ignition switch is turned on and the A / C request signal is input, step S10
In step S20, various data are initialized.
Then, various signals are input. Then, in step S30,
Performs compressor control. Here, the first compressor 111 is mainly operated, and the second compressor 122 is operated according to the idle stop condition and the heat load condition of the refrigeration cycle device 110. In particular, the second compressor 12 according to the heat load situation
The operation of No. 2 has the characteristics of the present invention, and the details will be described later. Further, in step S40, the set temperature Ts
The target outlet temperature TAO is calculated from et and various temperature signals, and the air conditioning airflow control is performed in step S50 so as to match the target TAO. Specifically, the evaporator rear air temperature Te in the evaporator 114 and the air flow rate of the air blower 114b are controlled. Hereinafter, the process returns to step S20 and the above control is repeated.

Next, details of the compressor control will be described with reference to the flowchart shown in FIG. 3 and the time chart shown in FIG. Following step S20, step S31
Then, the first compressor 111 is operated. This is when the vehicle is traveling and the first compressor 11 is driven by the driving force of the engine 10.
1 is operated (FIGS. 4 (a) (b) (c)). More specifically, the first compressor 111 is ON-OFF controlled according to the evaporator rear air temperature Te. (Fig. 4
(Not shown in (c)) Next, in step S32, it is determined from the idle stop determination signal whether or not the vehicle is in the idle stop state. If it is determined that the vehicle is in the idle stop state, in step S33,
The second compressor 122 is operated in place of the first compressor 111 that is stopped when the engine 10 is stopped (A in FIG. 4D).
By doing so, the cooling function is continued. Then, during the idle stop state, steps S32 to S33 are repeated.

On the other hand, in step S32, the engine is not in the idle stop state, that is, the vehicle is running.
Is determined to be operating, the heat load (difference ΔT between the vehicle compartment temperature Tr and the set temperature Tset described above) is determined in step S34, and if the heat load is high, the The 2 compressor 122 is operated.

That is, the first compressor 1 is driven by the engine 10.
Even when 11 is operated, the vehicle compartment temperature Tr is very high and the difference ΔT from the set temperature Tset is the same as when the vehicle is driven after being left in the hot sun in summer.
Is greater than or equal to the predetermined value ΔT1 (Y in step S34).
In the case of ES), the second compressor 122 is operated together with the first compressor 111 (B in FIG. 4D) (step S35). Then, both compressors 111 and 122
The vehicle interior temperature Tr is gradually decreased by the operation of, and when the temperature difference ΔT between the vehicle interior temperature Tr and the set temperature Tset falls below a predetermined value ΔT1 (C in FIG. 4 (e)), the second compressor 122 is stopped (D in FIG. 4D) (NO in step S34 to step S3).
6).

As a result, the vehicle compartment temperature Tr and the set temperature T
The operation of the second compressor 122 is added according to the difference ΔT from the set, and the discharge flow rate of the refrigerant is increased to increase the discharge flow rate of the refrigerant as compared with the operation of the first compressor 111 alone ((a) in FIG. The capacity can be improved ((a) in FIG. 4 (e)), and the improvement in the cooling capacity enables the first compressor 111 to be reduced in size and weight. Note that, when the engine 10 is stopped, the cooling function can be continued by operating the second compressor 122.

Further, the heat load of the refrigeration cycle apparatus 110 is regarded as a difference ΔT between the vehicle compartment temperature Tr and the set temperature Tset, and the second compressor 122 is operated / stopped by comparison with a predetermined value ΔT1. Therefore, it is possible to easily control the combined use of the second compressor 122 by utilizing the temperature signals of the respective parts normally used for controlling the refrigeration cycle apparatus 110. Further, since the vehicle compartment temperature Tr is used among the temperature signals, the timing at which the second compressor 122 should be operated together becomes clear, and it can be effectively used for a response to a cooldown in the summer, for example.

(Other Embodiments) In the first embodiment, the heat load required for the refrigeration cycle apparatus 110 is regarded as the difference ΔT between the vehicle interior temperature Tr and the set temperature Tset. Instead, the evaporator rear air temperature Te
Alternatively, the temperature of air blown into the passenger compartment, the target air temperature TAO, or the like may be used.

Further, one threshold value may be set for the vehicle interior temperature Tr, and the second compressor 122 may be turned on and off using the threshold value as a determination value.

If the second cycle compressor is provided in addition to the compressor provided in the refrigeration cycle apparatus 110,
The target vehicle may be applied to a hybrid vehicle in which the engine is stopped mainly at low speed or when the vehicle is stopped, instead of the idle stop vehicle, and similar effects can be obtained.

[Brief description of drawings]

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

FIG. 2 is a flowchart showing control of the entire refrigeration cycle apparatus.

FIG. 3 is a flowchart showing control of a compressor.

4A is a vehicle speed during control in FIG. 3, FIG. 4B is an input state of an A / C request signal, and FIG. 4C is an ON state of a first compressor.
-OFF state, (d) is an ON-OFF state of the second compressor, (e) is a time chart showing the vehicle interior temperature.

[Explanation of symbols]

10 engine 100 Vehicle cooling system 110 Refrigeration cycle device 111 First compressor 121 motor 122 Second compressor 130 control device

Claims (3)

[Claims] 1. A first compressor, which is applied to a vehicle in which an engine (10) is stopped when a vehicle is temporarily stopped during traveling operation, and which operates by receiving a driving force of the engine (10). Refrigerating cycle device (11) for cooling the air by compressing the refrigerant with 111) and then condensing, expanding and evaporating the refrigerant.
0), a second compressor (122) arranged in parallel with the first compressor (111) and compressing the refrigerant by driving a motor (121); A control device (130) for controlling the operation of (122) is provided, and when the engine (10) is stopped during the operation of the refrigeration cycle device (110), the second compressor () is controlled by the control device (130). 122) in the vehicle cooling device, the controller (130) controls the refrigeration cycle device (110) even when the first compressor (111) is operated by the engine (10). A vehicle air conditioner characterized in that the second compressor (122) is operated and stopped according to the heat load of the vehicle. 2. The heat load of the refrigeration cycle apparatus (110) is represented by a difference (ΔT) between a cooling temperature (Tr) at a predetermined portion and a set temperature (Tset) set by an occupant, and the second compressor. (122) is the difference (ΔT) between the two temperatures
The air conditioner for a vehicle according to claim 1, wherein the air conditioner is activated when the temperature is equal to or higher than a predetermined value (ΔT1), and is stopped when the difference (ΔT) between the two temperatures is lower than the predetermined value (ΔT1). 3. A cooling temperature (Tr) at the predetermined portion
Is the vehicle compartment temperature (Tr), The vehicle cooling device according to claim 2.