JPH11180138A - Refrigeration cycle - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When starting a refrigerant compressor 7 in a heater mode in which a hot gas heater circuit 32 is used, the discharge pressure of the refrigerant compressor 7 is increased, and the refrigerant is discharged from the discharge port of the refrigerant compressor 7. Provided is an air conditioner for a vehicle including a refrigeration cycle 5 capable of increasing a discharge capacity to be discharged. SOLUTION: In order to assist the heating capability of a hot water heater of a hot water type heating device, refrigerant compression is performed when a refrigerant compressor 7 is started in a heater mode in which a hot gas heater circuit 32 for supplying hot gas to an evaporator 6 is used. The first and second solenoid valves 33 until the predetermined condition is satisfied after the machine 7 is started.
By closing the valve 34, the discharge pressure of the refrigerant compressor 7 is increased to increase the pressure difference of the refrigeration cycle 5, and then the second solenoid valve 34 is opened to allow the refrigeration cycle 5 to have a hot gas heater circuit 32. Was formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigeration cycle for heating a room, and more particularly to a high-temperature, high-pressure gas refrigerant discharged from a refrigerant compressor, which is guided to a refrigerant evaporator, and an air conditioning duct is provided at the refrigerant evaporator. The present invention relates to a vehicle air conditioner provided with a refrigeration cycle that heats air flowing through the inside and heats a vehicle interior.

[0002]

2. Description of the Related Art Conventionally, as a heating device for a vehicle, cooling water for cooling an engine is guided to a hot water heater in an air conditioning duct, and the hot water heater heats air flowing in the air conditioning duct to heat the vehicle interior. A hot water type heating device is common. However, such a hot water type heating device has a remarkable heating capacity when the engine is started to start the hot water type heating device when the outside air temperature is low and the cooling water temperature is low, that is, when the hot water type heating device starts up. There is a shortage.

[0003] In order to solve the above problems,
For example, in Japanese Patent Application Laid-Open No. Hei 5-223357, high temperature discharged from a discharge port of a compressor of a refrigeration cycle,
A refrigeration cycle in which high-pressure gas refrigerant (hot gas) is guided to a refrigerant evaporator through a decompression device, and the refrigerant evaporator heats air flowing in an air conditioning duct, thereby assisting the heating capacity of the hot water heater. A vehicle air conditioner provided with an (auxiliary heating device) has been proposed.

Further, the compressor is frequently turned on and off.
To perform capacity control and pressure control without
It is conceivable to incorporate a variable displacement compressor into the refrigeration cycle (prior art).

[0005]

However, in the prior art, the variable displacement compressor is configured such that the lower the suction pressure sucked from the suction port, the smaller the discharge capacity discharged from the discharge port. Therefore, when the heating operation is started in the hot gas heater circuit, if the heating heat load is large, that is, if the suction temperature of the air sucked into the evaporator is equal to or lower than a predetermined temperature (for example, 0 ° C.), the compressor of the compressor is started. Since the high-low pressure difference between the high pressure and the low pressure of the refrigeration cycle, which is a factor for increasing the discharge capacity, is not so large, the discharge capacity of the compressor does not increase forever. As a result, since the flow rate of the high-temperature refrigerant flowing into the evaporator is small, there arises a problem that the auxiliary heating performance for assisting the heating capacity of the hot water heater cannot be sufficiently exhibited.

[0006] Conventionally, when starting the heating operation, the blower is stopped until the temperature of the cooling water for cooling the engine rises, for example, to 40 ° C. or higher, in order to prevent the blowing of the cool air from the outlet. (Water temperature delay control of the blower) is performed. In the case of such a vehicle air conditioner, in a vehicle equipped with an engine with a small amount of exhaust heat, the temperature of the cooling water does not rise to, for example, 40 ° C. or more when the outside air temperature is extremely low at −30 ° C. or less. However, there is a problem in that the interior of the vehicle cannot be heated and the interior of the vehicle cannot be heated.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the refrigerant cross-sectional area of the refrigerant passage from the outlet of the refrigerant compressor to the inlet of the refrigerant evaporator when starting the heating operation for operating the refrigerant circulation circuit. An object of the present invention is to provide a refrigeration cycle that can increase the discharge pressure of a compressor and increase the discharge capacity discharged from a refrigerant compressor. In addition, the present invention provides a vehicle air conditioner capable of heating the interior of a vehicle by quickly raising the temperature of cooling water to a predetermined value or more even in extremely cold weather.

[0008]

Means for Solving the Problems Claims 1 to 4
According to the invention described in the above, when the heating operation for operating the refrigerant circulation circuit is started, the passage cross-sectional area of the refrigerant passage from the outlet of the refrigerant compressor to the inlet of the refrigerant evaporator is reduced, so that the refrigerant is discharged from the refrigerant compressor. Since the refrigerant discharge pressure can be increased, the difference between the high pressure and the low pressure in the refrigeration cycle can be increased. As a result, even when the variable displacement compressor is incorporated in the refrigeration cycle, the discharge capacity of the refrigerant discharged from the discharge port of the refrigerant compressor can be increased, so that a sufficient amount of refrigerant flows into the refrigerant evaporator. The heating performance can be sufficiently exhibited.

According to the fifth aspect of the present invention, when the heating operation for operating the refrigerant circulation circuit is started, the refrigerant circulation circuit is closed until a predetermined condition is satisfied after the start of the refrigerant compressor. Since the discharge pressure of the refrigerant discharged from the discharge port of the refrigerant compressor can be increased, a high-low pressure difference between the high pressure and the low pressure of the refrigeration cycle can be increased. Thereby, the same effect as the first aspect of the invention can be achieved.

According to the invention, when the discharge pressure of the refrigerant discharged from the discharge port of the refrigerant compressor is low at the time of starting the heating operation for operating the refrigerant circulation circuit, the valve body of the variable throttle valve is activated. By reducing the opening degree of the throttle hole, it is possible to increase the discharge pressure of the refrigerant discharged from the discharge port of the refrigerant compressor, so that the difference between the high pressure and the low pressure of the refrigeration cycle is increased. Can be. Thereby, the same effect as the first aspect of the invention can be achieved.

According to the seventh aspect of the present invention, when the heating operation for operating the refrigerant circulation circuit is started, the differential pressure regulating valve is maintained until the discharge pressure of the refrigerant discharged from the discharge port of the refrigerant compressor rises to a predetermined value or more. By closing the valve, the discharge pressure of the refrigerant discharged from the refrigerant compressor can be increased,
The difference between the high pressure and the low pressure in the refrigeration cycle can be made large. Thereby, the same effect as the first aspect of the invention can be achieved.

According to the present invention, since the discharge pressure of the refrigerant discharged from the discharge port of the refrigerant compressor can be increased, the auxiliary heating performance for assisting the heating capacity of the hot water heater can be sufficiently improved. Can demonstrate. At this time, as the temperature of the refrigerant evaporator rises, the temperature of the hot water heater rises. In addition, the amount of exhaust heat of the internal combustion engine increases as the refrigerant compressor that operates the refrigerant circulation circuit increases the driving load of the internal combustion engine. Therefore, the temperature of the cooling water rises quickly, so that the temperature of the cooling water rises above a predetermined value, and the blower operates to heat the vehicle interior.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Configuration of First Embodiment] FIGS. 1 to 10 show a first embodiment of the present invention.
Is a diagram showing an air conditioning unit of the vehicle air conditioner, and FIG. 2 is a diagram showing a refrigeration cycle of the vehicle air conditioner.

The vehicle air conditioner according to the present embodiment includes an air conditioner unit (air conditioner unit) 1 for air conditioning the interior of a vehicle equipped with a diesel engine (hereinafter abbreviated as engine), which is an internal combustion engine serving as a main heat source for heating. The air-conditioning means (actuator) is connected to an air-conditioning control device (hereinafter, air-conditioner E).
This is an automatic air conditioner for a vehicle configured to be controlled by a CU (referred to as CU) 10.

The air-conditioning unit 1 includes an air-conditioning duct 2 forming a ventilation path for guiding conditioned air into the vehicle interior. An outside air suction port 11, an inside air suction port 12, and an inside / outside air switching door 13 are provided at the most upstream side of the air conditioning duct 2, and a centrifugal blower 3 is provided downstream of the air. The defroster outlet 14, the face outlet 15, the foot outlet 1 are located at the most downstream side of the air conditioning duct 2.
Six and two outlet switching doors 17 and 18 are provided.

The inside / outside air switching door 13 and the two air outlet switching doors 17 and 18 are driven by actuators 13a, 17a and 18a such as servomotors (see FIG. 7). The centrifugal blower 3 includes a scroll casing provided integrally with the air conditioning duct 2 and a blower motor 1 controlled by a blower drive circuit 19a (see FIG. 7).
9 and a centrifugal fan 20 driven to rotate by the blower motor 19.

Next, on the upstream side of the air outlet switching doors 17 and 18, a hot water heater 4 for reheating the air that has passed through the evaporator 6, which will be described later, closes a part of the ventilation passage in the air conditioning duct 2. It is installed as follows. This hot water heater 4
Is provided in the middle of a cooling water circulation circuit 22 in which a cooling water circulating flow is generated by a water pump 21 driven by the engine E. When the hot water valve 23 installed in the cooling water circulation circuit 22 opens, the hot water heater 4 recirculates the cooling water that has absorbed the exhaust heat of the engine E, and uses the cooling water as a heating heat source. It is a heat exchanger for heating.

Here, the engine E, the hot water heater 4, the cooling water circulation circuit 22 and the hot water valve 23 constitute a hot water heating device (main heating device). The hot water heater 4 has an air mixing door 2 for adjusting the amount of air passing through the hot water heater 4 and the amount of air bypassing the hot water heater 4.
4 is attached. This air mix door 24
Is driven by an actuator 24a (see FIG. 7) such as a servomotor.

Next, between the centrifugal blower 3 and the hot water heater 4, an evaporator 6, which is a component of the refrigeration cycle 5 mounted on the vehicle, is installed so as to cover the entire ventilation path in the air conditioning duct 2. Have been. The above refrigeration cycle 5
A first refrigerant circuit (hereinafter referred to as a normal refrigeration cycle circuit) 31, a second refrigerant circuit (hereinafter referred to as a hot gas heater circuit) 32, and a first circuit for switching between the normal refrigeration cycle circuit 31 and the hot gas heater circuit 32. , A second solenoid on-off valve (hereinafter, referred to as first and second solenoid valves) 33 and 34.

The normal refrigeration cycle circuit 31 converts the high-temperature, high-pressure gas refrigerant discharged from the discharge port of the refrigerant compressor 7 into
First solenoid valve 33 → condenser (refrigerant condenser) 35 → receiver (gas-liquid separator) 36 → check valve 36 a → expansion valve (first
This is a refrigerant circuit (normal refrigeration cycle) in which the refrigerant flows through the pressure reducing device) 37 → the evaporator 6 → the accumulator (gas-liquid separator) 38 and returns to the inside of the refrigerant compressor 7.
Further, the hot gas heater circuit 32 converts the high-temperature, high-pressure gas refrigerant (hot gas) discharged from the discharge port of the refrigerant compressor 7 from the second solenoid valve 34 to the fixed throttle (second pressure reducing device) 3.
9 → Evaporator 6 → Flow accumulator 38
This is a refrigerant circuit (hot gas bypass cycle) that is returned to the inside of the refrigerant compressor 7.

The first solenoid valve 33 is connected to the discharge port of the refrigerant compressor 7 and the condenser 35 in the ordinary refrigeration cycle circuit 31.
Is installed in the middle of the refrigerant passage between the inlet and the inlet. Second
The solenoid valve 34 corresponds to the refrigerant passage restricting means of the present invention.
Is installed in the middle of the refrigerant passage from the outlet of the fixed throttle 39 to the inlet of the fixed throttle 39. Then, the first solenoid valve 33 opens,
When the second solenoid valve 34 closes, the refrigerant circulates through the normal refrigeration cycle circuit 31. When the first solenoid valve 33 is closed and the second solenoid valve 34 is opened, the refrigerant recirculates in the hot gas heater circuit 32. The first and second solenoid valves 3
Reference numerals 3 and 34 constitute circulation circuit switching means. Reference numeral 25 denotes a cooling fan which is rotationally driven by a drive motor 26, and forcibly blows outdoor air (outside air) to the condenser 35.

The evaporator 6 corresponds to the refrigerant evaporator of the present invention. When the refrigerant flows in the refrigeration cycle circuit 31, the low-temperature gas-liquid two-phase refrigerant flowing from the expansion valve 37 evaporates and passes through. Works as a cooling heat exchanger. Further, the evaporator 6 heats the air that flows by flowing the high-temperature gas refrigerant flowing from the fixed throttle 39 when the refrigerant flows in the hot gas heater circuit 32.
It works as a heat exchanger for heating (auxiliary heating device, hot gas heater of auxiliary heat source system). Here, the expansion valve 37 is
In addition to adiabatic expansion of the refrigerant, the refrigerant circulation amount is adjusted according to the degree of superheat of the refrigerant at the outlet of the evaporator 6.

Next, the external variable displacement type compressor according to the present embodiment will be briefly described with reference to FIGS.
Here, FIG. 3 is a diagram showing an external variable displacement type compressor.

The external variable displacement type compressor is of a known type, for example, a wobble type compressor whose discharge capacity can be changed.
An electromagnetic clutch 8 for transmitting and interrupting the power of the engine E to and from the refrigerant compressor 7; and an electromagnetic displacement control valve for varying the displacement of the refrigerant compressor 7 (corresponding to a displacement displacement means of the present invention). 9).

The electromagnetic clutch 8 has a stator housing 42 fixed to the housing of the refrigerant compressor 7 via an annular mounting flange 41 and a pulley 43 connected to the engine E via a belt V, which are joined to the outer periphery. Rotor 44
And an armature 45 having a friction surface frictionally engaged with the friction surface of the rotor 44 and opposed to the rotor 44 with a small gap therebetween. Coil 47 that causes the rotor 44 to be attracted to the rotor 44 against the elastic force of the rubber hub (elastic body) 46
And an inner hub 49 connecting the armature 45 and the rotating shaft 50 of the refrigerant compressor 7 via an outer hub 48 and a rubber hub 46.

The power of the engine E is transmitted to the rotating shaft 50 of the refrigerant compressor 7 via the electromagnetic clutch 8.
0 rotates. A swash plate 51 is integrally rotatably connected to the rotating shaft 50, and the piston 52 reciprocates in the axial direction as the swash plate 51 rotates. Furthermore, swash plate 5
The stroke of the piston 52 is changed by changing the inclination angle (θ) of 1 to change the discharge capacity discharged from the discharge port of the refrigerant compressor 7. For this reason, the swash plate 51 is swingably connected to the rotating shaft 50. Specifically, the swash plate 51 is swingably supported by the spherical support portion 51a.

The inclination angle (θ) of the swash plate 51 is
2, ie, the pressure in the crank chamber 53 acting on the back of the piston 52, that is, the control pressure Pc, and the pressure in the cylinder 54 in which the piston 52 reciprocates (discharge pressure Pd and suction pressure Ps). It changes depending on the balance. Therefore, by adjusting the control pressure (Pc) in the crank chamber 53, the inclination angle (θ) of the swash plate 51 can be changed.

The gas refrigerant compressed by the cylinder 54 of the refrigerant compressor 7 is discharged into a discharge chamber 55, from which the gas refrigerant is discharged through a discharge port (not shown). The refrigerant is sucked into the cylinder 54 of the refrigerant compressor 7 through the suction chamber 56. The suction chamber 56 communicates with the outlet of the evaporator 6 via a suction port 57. The electromagnetic pressure control valve 9 changes the control pressure (Pc) of the crank chamber 53 using the discharge pressure (Pd) of the discharge chamber 55 and the suction pressure (Ps) of the suction chamber 56. It is configured.

As described above, when the electromagnetic coil 47 of the electromagnetic clutch 8 is in the energized state (ON), the armature 45 of the electromagnetic clutch 8 is attracted to the rotor 44 and the rotor 44 and the armature 45 frictionally engage with each other. E
Is transmitted to the rotating shaft 50 of the refrigerant compressor 7 via the belt V and the electromagnetic clutch 8. As a result, when the refrigeration cycle 5 is started, the air cooling action or the air heating action by the evaporator 6 is performed. Also, the energization of the electromagnetic coil 47 of the electromagnetic clutch 8 is stopped (OF
In the case of F), the armature 45 of the electromagnetic clutch 8 is separated from the rotor 44 and the frictional engagement between the rotor 44 and the armature 45 is interrupted. As a result, the power of the engine E is not transmitted to the rotating shaft 50 of the refrigerant compressor 7, and the air cooling action or the air heating action by the evaporator 6 is stopped.

Next, the electromagnetic displacement control valve 9 of this embodiment will be described with reference to FIGS. A discharge pressure chamber 61 communicating with the discharge chamber 55, a suction pressure chamber 62 communicating with the suction chamber 56, and a control pressure chamber 63 communicating with the crank chamber 53 are provided in a valve body 60 of the electromagnetic displacement control valve 9. Is provided. The discharge pressure chamber 61 is provided in the control pressure chamber 63 with the variable throttle 6 whose opening is adjusted by the valve 64.
And 5. In the present embodiment, the valve 64 and the variable throttle 65 constitute a variable throttle mechanism. Further, the suction pressure chamber 62 communicates with the control pressure chamber 63 via a fixed throttle 66. The relationship between these pressure chambers is clearly shown in FIGS.

A bellows (pressure responsive mechanism) 67 made of a material that can expand and contract is provided inside the suction pressure chamber 62. The bellows 67 has a predetermined internal pressure (Pb) in advance. Is set, and the internal pressure (P
The bellows 67 expands and contracts due to a change in the suction pressure (Ps) with respect to b). The valve body 64 is configured to be displaced via the rod 68 by the expansion and contraction of the bellows 67. The bellows 67 and the valve body 64 are configured so that the electromagnetic force of the electromagnetic mechanism also acts.

That is, the electromagnetic mechanism of the electromagnetic capacity control valve 9 of the present embodiment comprises an electromagnetic coil 69 and a fixed magnetic pole member 70.
And a movable magnetic pole member (plunger) 71 attracted in the direction of the fixed magnetic pole member 70 (the direction in which the bellows 67 extends) by the electromagnetic force (attractive force) of the electromagnetic coil 69, and a spring load (rod 68) And a coil spring 72 for applying a lateral biasing force).
A rod 73 is connected to the center of the movable magnetic pole member 71,
The rod 73, the valve body 64, and the rod 68 are integrally connected and are integrally displaced.

Therefore, the electromagnetic capacity control valve 9 changes the set value of the suction pressure (Ps) of the refrigerant compressor 7 by the control current from the air conditioner ECU 10 as shown in the graph of FIG. This is a discharge capacity changing means for changing the discharge capacity discharged from the discharge port of the compressor 7.
That is, the electromagnetic capacity control valve 9 has a structure in which an external force applied to the movable magnetic pole member 71 and the bellows 67 is varied by applying a control current to the electromagnetic coil 69, and the suction pressure (P
By varying the relationship between the opening degree of the valve body 64 and s), for example, control is performed so that the actual post-evaporation temperature (TE) becomes the target post-evaporation temperature (TEO).

Next, the air conditioner ECU 10 will be described with reference to FIG. Here, FIG. 7 is a diagram showing a control system of the vehicle air conditioner. An air conditioner ECU (heating control means) 10 for controlling each air conditioner in the air conditioner unit 1 includes an air conditioner operation panel (not shown) provided on the front of the passenger compartment.
Each switch signal from each of the above switches is input. In addition, a CPU, a ROM,
A well-known microcomputer including a RAM or the like is provided, and each sensor signal from each sensor is A / D-converted by an input circuit (not shown) and then input to the microcomputer.

When an ignition switch (key switch) for starting and stopping the engine E of the vehicle is turned on (IG / ON), the air conditioner ECU 10 supplies a battery (not shown) as a vehicle-mounted power supply mounted on the vehicle. ), The control process is started when DC power is supplied. On the air conditioner operation panel, there are a mode changeover switch 75 for switching the air conditioning mode to one of the cooling operation mode, the auxiliary heating operation mode, and the normal heating operation mode, and a temperature setting switch for setting the temperature in the passenger compartment to a desired temperature. (Temperature setting means) 76, an air conditioner switch 77 for instructing start or stop of the refrigeration cycle 5 (electromagnetic clutch 8 of the refrigerant compressor 7), and an air volume switching lever 7 for switching the air volume of the centrifugal fan 20
8 etc. are installed.

The cooling operation mode is a cooler mode in which the normal refrigeration cycle circuit 31 operates only the refrigeration cycle 5. Also, the normal heating operation mode is
This is a heater mode in which the hot water valve 23 is opened and the vehicle interior is heated only by the hot water heating device. In the auxiliary heating operation mode, the hot gas heater circuit 3 is used to open the hot water valve 23 and to assist the heating capacity of the hot water heating device.
2 is a heater mode in which the refrigeration cycle 5 is operated. Here, the mode switching switch 75 is used to operate the refrigeration cycle 5 in the normal refrigeration cycle circuit 31, open the hot water valve 23, and switch to the dehumidifying operation mode in which the hot water heating device dehumidifies and heats the vehicle interior. Is also good.

Of the above, the air volume switching lever 78 is
It has lever positions of F, AUTO, ME1, ME2, and HI. When the lever position is OFF, a command to turn off the blower motor 19 of the centrifugal blower 3 is issued. When the lever position is AUTO, the blower control voltage of the blower motor 19 is changed from 0 step (OFF) to 32 steps (HI). Command to automatically control continuously or step by step. When the lever positions are ME1, ME2, and HI, the blower control voltage of the blower motor 19 is set to the minimum value (minimum air volume), intermediate value 1 (intermediate air volume 1), intermediate value 2 (intermediate air volume 2), and maximum value, respectively. (Maximum airflow).

The air conditioner ECU 10 has an inside air temperature sensor (inside air temperature detecting means) 81 for detecting the air temperature in the vehicle compartment (hereinafter referred to as inside air temperature) and an air temperature outside the vehicle compartment (hereinafter outside air temperature). An outside air temperature sensor (outside air temperature detecting means) 82 for detecting, a solar radiation sensor (solar radiation detecting means) 83 for detecting an amount of solar radiation entering the vehicle cabin, and an air temperature immediately after passing through the evaporator 6 (hereinafter referred to as a post-evaporation temperature). A cooling water temperature sensor (cooling water temperature detecting means) 85 for detecting the temperature of the cooling water flowing into the hot water heater 4;
Respective sensor signals from a refrigerant pressure sensor (high pressure detection means) 86 for detecting a high pressure (discharge pressure: Pd) of the refrigeration cycle 5 are input. The above-mentioned switches and sensors detect air-conditioning environmental factors necessary for air-conditioning the cabin of the automobile.

[Control Method of First Embodiment] Next, the blower control voltage control by the air conditioner ECU 10 of the present embodiment will be briefly described with reference to FIGS. Here, FIG. 8 is a flowchart showing a blower delay control method by the air conditioner ECU 10.

When the ignition switch is turned on and DC power is supplied to the air conditioner ECU 10, execution of the routine shown in FIG. 8 is started. At this time, first, the storage contents and the like of the data processing memory (RAM) are initialized (step S1). The processing in step S1 is performed by the air conditioner ECU.
It is performed only at the time of startup of 10. Next, various data are read into the data processing memory. That is, the set position of the mode changeover switch 75, the lever position of the air volume changeover lever 78, and the cooling water temperature detected by the cooling water temperature sensor 85 are input (cooling water temperature detecting means: step S2).

Next, it is determined whether or not the position of the air volume switching lever 78 is AUTO (step S3). When the determination result is NO, the blower control voltage is fixed to the blower control voltage corresponding to the lever position of the air volume switching lever 78 (step S4). Thereafter, the process exits the routine of FIG. If the determination result of step S3 is YES, it is determined whether the auxiliary heating operation mode or the normal heating operation mode is selected. Specifically, the target outlet temperature (TA
It is determined whether or not O) is equal to or higher than a predetermined temperature, or whether or not the mode changeover switch 75 has been set to the auxiliary heating operation mode (step S5). If the result of this determination is NO, normal blower control is performed. For example, a blower control voltage corresponding to the target blowout temperature (TAO) is set (step S6). Thereafter, the process exits the routine of FIG.

If the decision result in the step S5 is YES, it is determined whether or not the auxiliary heating operation mode or the normal heating operation mode is started. That is, it is determined whether or not it is within a predetermined time (for example, 10 minutes) after starting the engine E (step S7). If the result of this determination is NO, the operation proceeds to the control processing of step S6.
If the determination result of step S7 is YES, it is determined whether or not the cooling water temperature (TW) detected by the cooling water temperature sensor 85 is equal to or higher than a predetermined cooling water temperature (for example, 40 ° C.) TWa ( Step S8). If this determination is NO, the blower motor 19 is turned off (step S
9). Thereafter, the process exits the routine of FIG.

If the decision result in the step S8 is YES, a heating initial blower control is performed. That is, a blower control voltage corresponding to a predetermined blower delay characteristic diagram (not shown) is set (step S10). Thereafter, the process exits the routine of FIG. Specifically, the blower motor 19 is turned off until a first predetermined time (for example, 8 seconds to 30 seconds) has elapsed since the start of the auxiliary heating operation or the normal heating operation. Controls the blower control voltage so that the control mode becomes the Lo mode. Then, when a second predetermined time (for example, 2 seconds to 30 seconds) has elapsed since the air volume mode was changed to the Lo mode, the blower control voltage is increased continuously or stepwise from the Lo mode so that the air volume mode becomes the HI mode. .

Next, air-conditioning mode control by the air-conditioning ECU 10 of the present embodiment will be briefly described with reference to FIGS. Here, FIG. 9 is a flowchart showing a method of controlling the discharge capacity by the air conditioner ECU 10.

When the ignition switch is turned on and DC power is supplied to the air conditioner ECU 10, execution of the routine shown in FIG. 9 is started. At this time, first, the storage contents and the like of the data processing memory (RAM) are initialized (step S11). The process in step S11 is performed by the air conditioner E
It is performed only when the CU 10 is started. Next, various data are read into the data processing memory. That is, switch signals from various switches and sensor signals from various sensors shown in FIG. 7 are input (cooling water temperature detecting means, high pressure detecting means, post-evaporation temperature detecting means: step S12).

Next, the following equation 1 previously stored in the ROM
(TAO) is calculated based on the following equation (target blowing temperature determining means: step S13).

## EQU1 ## TAO = Kset × Tset−KR × TR−K
AM × TAM−KS × TS + C Here, Tset is the set temperature set by the temperature setting switch 76, TR is the inside air temperature detected by the inside air temperature sensor 81, and TAM is the outside air temperature detected by the outside air temperature sensor 82. Where TS is the amount of solar radiation detected by the solar radiation sensor 83. Kset, KR, KAM, and KS are gains, and C is a correction constant.

Next, it is determined whether or not the auxiliary heating operation mode has been selected. Specifically, the target outlet temperature (TA
It is determined whether or not O) is equal to or higher than a predetermined temperature, or whether or not the mode changeover switch 75 has been set to the auxiliary heating operation mode (step S14). If the result of this determination is NO, the electromagnetic coil 47 of the electromagnetic clutch 8 is turned on (step S15). Next, the first solenoid valve 33 is opened, the second solenoid valve 34 is closed, and the refrigeration cycle 5 is operated in the normal refrigeration cycle circuit 31 (step S).
16).

Next, a cooling heat load or a heating heat load is determined based on the target outlet temperature (TAO), and a target post-evaporation temperature (TEO) is determined from the cooling heat load or the heating heat load. Specifically, the target post-evaporation temperature (TEO) is calculated so as to increase as the target outlet temperature (TAO) increases (step S17). Next, the post-evaporation temperature sensor 8
The capacity control of the refrigerant compressor 7 is performed so that the actual post-evaporation temperature (TE) detected at 4 becomes equal to the target post-evaporation temperature (TEO). Specifically, the control current to the electromagnetic coil 69 of the electromagnetic displacement control valve 9 is controlled (step S1).
8). Thereafter, the process exits the routine of FIG.

If the decision result in the step S14 is YES, the electromagnetic coil 47 of the electromagnetic clutch 8 is turned on (step S19). At this time, the air mix door 2
4 controls to the maximum heating operation position (MAX / HOT position). Next, it is determined whether or not the refrigerant compressor 7 has started. Specifically, it is determined whether it is within a predetermined time (for example, 10 seconds to 10 minutes) after the start of the refrigerant compressor 7 (step S20). If the determination result is NO, the first solenoid valve 33 is closed, the second solenoid valve 34 is opened, and the refrigeration cycle 5
Is driven (step S21). Then, step S
The process proceeds to control process No. 17.

Note that, between step S21 and step S20, it is determined whether or not the cooling water temperature (TW) detected by the cooling water temperature sensor 85 is equal to or higher than a predetermined cooling water temperature (for example, 75 ° C.) TWb. If the determination is negative and the result of the determination is NO, the control process of step S21 is performed. If the result of the determination is YES, the refrigerant compressor 7 is stopped and the hot water heater 4 and the door of the air mix door 24 are closed. You may make it perform the blow-off temperature control by opening degree control.

It is determined whether the inside air temperature (TR) detected by the inside air temperature sensor 81 or the outside air temperature (TAM) detected by the outside air temperature sensor 82 is lower than a predetermined temperature (for example, 0 ° C.) Tb. (Step S22). If the result of this determination is NO, the operation proceeds to the control processing of step S21. If the determination result of step S22 is YES, the high pressure of the refrigeration cycle 5 (discharge pressure of the refrigerant compressor 7: Pd) detected by the refrigerant pressure sensor 86 is a predetermined pressure (for example, 2 kg / cm ² G). It is determined whether or not it has increased beyond Pda (step S23). If the result of this determination is YES, control proceeds to the control process in step S21.

If the result of the determination in step S23 is NO, it is determined whether or not a predetermined time (for example, 10 seconds) has elapsed since the start of the refrigerant compressor 7 (step S24). If the result of this determination is YES, control proceeds to the control process in step S21. Step S24
If the determination result is NO, the first solenoid valve 33 and the second solenoid valve 34 are closed (step S25). Thereafter, the process proceeds to the control processing of step S17. Each control process of the flowchart of FIG. 8 and the flowchart of FIG. 9 includes other air mix control (blowing temperature control),
It is executed repeatedly and alternately together with the suction port control and the outlet control.

[Operation of First Embodiment] Next, the operation of the vehicle air conditioner 1 of this embodiment will be briefly described with reference to FIGS. Here, FIGS. 4 and 5 are diagrams showing the operation state of the electromagnetic displacement control valve and the operation state of the refrigerant compressor. 4 and 5, the arrangement state of each part of the electromagnetic displacement control valve is different from that of FIG. 3 for simplification of illustration.

FIG. 4 shows a state in which the discharge capacity discharged from the discharge port of the refrigerant compressor 7 is large, and the suction pressure (Ps) rises above the internal pressure Pb of the bellows 67 due to an increase in the cooling heat load. Then, since the bellows 67 contracts, the rods 68 and 73 move in the direction of the arrow in FIG. 4A, whereby the valve body 64 is displaced in the same direction to decrease the opening of the variable throttle 65. Therefore, the pressure loss between the discharge pressure chamber 61 and the control pressure chamber 63 increases, and the control pressure (Pc) in the control pressure chamber 63 decreases.

As the control pressure (Pc) decreases, the pressure in the crank chamber 53 decreases, and the back pressure of the piston 52 decreases. Therefore, as shown by the arrow in FIG.
And the inclination angle (θ) of the swash plate 51 increases. As a result, the stroke of the piston 52 increases, and the discharge capacity discharged from the discharge port of the refrigerant compressor 7 increases. Thereby, the flow rate of the refrigerant circulating in the refrigeration cycle 5 increases, the flow rate of the refrigerant flowing into the evaporator 6 increases, and the cooling capacity of the evaporator 6 increases.
s) gradually decreases.

When the suction pressure (Ps) drops below the internal pressure (Pb) of the bellows 67, the bellows 6
7 extends, the rods 68 and 73 move in the direction of the arrow in FIG. 5A, whereby the valve body 64 is displaced in the same direction to increase the opening of the variable throttle 65. Therefore, the pressure loss between the discharge pressure chamber 61 and the control pressure chamber 63 decreases, and the control pressure (Pc) in the control pressure chamber 63 increases.

When the pressure in the crank chamber 53 rises due to the rise of the control pressure (Pc), the swash plate 51 rises as shown by an arrow in FIG. 5B, and the inclination angle (θ) of the swash plate 51 becomes smaller. As a result, the stroke of the piston 52 decreases, and the discharge capacity discharged from the discharge port of the refrigerant compressor 7 decreases. As a result, the flow rate of the refrigerant circulating in the refrigeration cycle 5 decreases, the flow rate of the refrigerant flowing into the evaporator 6 decreases, and the cooling capacity of the evaporator 6 decreases.
The suction pressure (Ps) gradually increases.

As described above, the bellows 67 expands and contracts in response to the change in the suction pressure (Ps), so that the control pressure (Pc) is adjusted to change the discharge capacity discharged from the discharge port of the refrigerant compressor 7. In the control, the electromagnetic mechanism changes the set value of the suction pressure (Ps) based on the internal pressure (Pb) of the bellows 67. Electromagnetic coil 6
The direction of the electromagnetic force 9 is the direction in which the bellows 67 extends, so that the electromagnetic force of the electromagnetic coil 69 acts on the valve body 64 in a direction to increase the opening of the variable throttle 65.

On the other hand, since the electromagnetic force of the electromagnetic coil 69 is proportional to the control current (In) flowing through the electromagnetic coil 69, as the control current (In) increases, the variable diaphragm 65 becomes larger.
, The control pressure (Pc) is increased, and the discharge capacity discharged from the discharge port of the refrigerant compressor 7 is reduced. Therefore, as shown in FIG. 6, the control current (I
As n) increases, the set value of the suction pressure (Ps) increases.

Here, the heating capacity of the hot water heater 4 is assisted.
Therefore, the refrigeration cycle 5 is connected to the hot gas heater circuit 32.
When switching to use, flow to the electromagnetic coil 69
Set the control current value to 0 (A) and set the suction pressure (Ps).
The fixed value is, for example, -1 kg / cm ^TwoBy using G, electromagnetic
Use the capacity control valve 9 with the operation state shown in FIG.
doing.

However, even if the control pressure (Pc) is controlled to be the lowest, the hot gas heater circuit 32
In an extremely cold region where the outside air temperature is, for example, −10 ° C. or lower, as shown by a broken line in the time chart of FIG.
The saturation pressure of the refrigerant becomes 1 kg / cm ² G or less, which is a factor of increasing the discharge capacity discharged from the discharge port of the refrigerant compressor 7 (between the high pressure and the low pressure of the refrigeration cycle 5).
Since the pressure difference cannot be obtained, the discharge capacity does not increase forever.

For this reason, as in the present embodiment, when the heat mode is started, the cooling water temperature (TW) of the engine E is set to a predetermined temperature (for example, 40 ° C.) Ta for the purpose of preventing the blowing of cold air into the vehicle interior. In the case of an air conditioner for a vehicle that performs water temperature delay control in which the blower motor 19 is turned off until the temperature rises above, when an engine with a small amount of exhaust heat is mounted, the temperature of the outside air (TAM) is -30 ° C or lower. In the region, the cooling water temperature (TW) is a predetermined temperature (for example, 40 ° C.) TW
centrifugal fan 20
It does not rotate, and it becomes impossible to heat the cabin.

Therefore, when starting the auxiliary heating operation mode for assisting the heating capacity of the hot water heater 4 of the hot water type heating apparatus, that is, when starting the refrigerant compressor 7 when operating the refrigeration cycle 5 in the hot gas heater circuit 32. , The first and second solenoid valves 33 and 34 are both closed, and the high pressure of the refrigeration cycle 5, that is, the discharge pressure (Pd) of the discharge port of the refrigerant compressor 7
To 2 kg / cm ² G or more, thereby increasing the discharge capacity of the refrigerant compressor 7. Thereafter, the second electromagnetic valve 34 is opened to configure the hot gas heater circuit 32. Changes in the discharge pressure (Pd) and the suction pressure (Ps) of the refrigerant compressor 7 are shown by solid lines in the time chart of FIG.

Therefore, when the second solenoid valve 34 is kept open, there is no difference between high and low pressures between the discharge pressure (Pd) and the suction pressure (Ps), and the discharge capacity remains the minimum. When the second electromagnetic valve 34 is closed once when the starting condition is satisfied, the discharge pressure (Pd) sharply rises, so that the discharge capacity of the refrigerant compressor 7 increases.

Here, when the auxiliary heating operation mode for assisting the heating capacity of the hot water heater 4 of the hot water type heating apparatus is started, that is, when the refrigeration cycle 5 is operated by the hot gas heater circuit 32, the refrigerant compressor 7 is started. Sometimes, the second solenoid valve 34
(Predetermined conditions) are, for example, when the high pressure (discharge pressure) of the refrigeration cycle 5 detected by the refrigerant pressure sensor 86 is lower than ² kg / cm ² G, or when the evaporator 6 For example, when the suction temperature of the air sucked into the air (evaporating suction temperature) is 0 ° C. or less. The air suction temperature of 0 ° C. or less means that the inside air temperature (TR) detected by the inside air temperature sensor 81 is 0 ° C. or less when the suction port mode is the inside air circulation mode. In the mode, the outside air temperature (TAM) detected by the outside air temperature sensor 82 is 0 ° C. or less.

The condition (predetermined condition) for opening the second solenoid valve 34 after the start of the auxiliary heating operation mode, that is, after the start of the refrigerant compressor 7 when the refrigeration cycle 5 is operated by the hot gas heater circuit 32. This is the case, for example, when the high pressure of the refrigeration cycle 5 rises to ² kg / cm ² G or more, or when about 10 seconds have elapsed after the activation of the refrigerant compressor 7.

[Effects of the First Embodiment] As described above, the air-conditioning unit 1 according to the present embodiment has a temporary outside air temperature (TAM) of 0 ° C. or lower (particularly −
(20 ° C. or less), the discharge pressure (Pd) of the refrigerant compressor 7 is increased by closing the second solenoid valve 34 until the predetermined condition is satisfied after the refrigerant compressor 7 is started. Therefore, the difference between the high and low pressures of the refrigeration cycle 5 can be increased.

Thus, even when the external variable displacement type compressor as in the present embodiment is incorporated in the refrigeration cycle 5, the discharge capacity of the refrigerant compressor 7 can be increased. A refrigerant can be allowed to flow. As a result, if the outside air temperature (TA
Even if M) is 0 ° C. or lower, the heating capacity of the evaporator 6 can be improved. Therefore, in the refrigeration cycle 5 of the present embodiment,
The auxiliary heating performance for assisting the heating capacity of the hot water heater 4 can be sufficiently exhibited.

The air-conditioning unit 1 of the present embodiment
At the start of the auxiliary heating operation mode, the heat radiation temperature of the evaporator 6 can be increased immediately after the start of the engine E. Therefore, the surface temperature of the hot water heater 4 installed near the evaporator 6 in the air conditioning duct 2 increases. Therefore, the temperature of the cooling water flowing back through the hot water heater 4 rises quickly. In addition, since the refrigerant compressor 7 is belt-driven by the engine E via the electromagnetic clutch 8 in the auxiliary heating operation mode, the refrigerant compressor 7 increases the driving load of the engine E. As a result, the amount of heat exhausted from the engine increases, so that the temperature of the cooling water circulating in the cooling water circulation circuit 22 quickly rises. As a result, the temperature of the cooling water quickly rises to a predetermined temperature (for example, 40 ° C.) or higher. Therefore, even when performing blower delay control, the centrifugal fan 20 starts rotating immediately to quickly heat the passenger compartment. Can be.

[Second Embodiment] FIGS. 11 to 13 show a second embodiment of the present invention. FIG. 11 is a diagram showing a refrigeration cycle of a vehicle air conditioner, and FIG. FIG. 13 is a diagram showing a variable throttle valve incorporated therein, and FIG. 13 is a graph showing the opening degree of the variable throttle valve with respect to the high pressure of the refrigeration cycle.

In the refrigeration cycle 5 of this embodiment, the fixed throttle 39 of the first embodiment is changed to a variable throttle valve 27. The variable throttle valve 27 corresponds to the refrigerant passage throttle means of the present invention.
A valve housing 92 in which a throttle hole 91 is formed in the middle of a communication passage 90 communicating with a refrigerant passage for guiding the refrigerant to the refrigerant passage; a ball-shaped valve element 93 disposed in the valve housing 92 so as to be capable of reciprocating displacement; A diaphragm 96 for driving the valve body 93 via an operating rod 94 and a stopper 95;
7, an adjusting spring 98 for adjusting the valve opening pressure of the valve element 93.

Of the above, the valve element 93 adjusts the opening degree of the throttle hole 91, and is provided with a spring seat 99 at the lower part in the figure, against which an adjustment spring 98 contacts. Diaphragm 96
Corresponds to the valve body driving means of the present invention, and is housed in the housing 100. And the diaphragm 9
The high pressure of the refrigeration cycle 5 acts in the pressure chamber 101 surrounded by the dozing 100 and the dozing 100.

In the variable throttle valve 27 of the present embodiment, the high pressure of the refrigeration cycle 5 is guided into the pressure chamber 101 by the above configuration, and as shown in the graph of FIG. By fully closing the valve at a pressure of not more than ² cm ² G and having a valve characteristic in which the valve opening increases with an increase in the high-pressure pressure, even when the outside air temperature (TAM) is -20 ° C. or less at the start of the auxiliary heating operation mode. In addition, the discharge capacity of the refrigerant compressor 7 can be increased.

[Third Embodiment] FIG. 14 shows a third embodiment of the present invention and is a view showing a differential pressure valve incorporated in a refrigeration cycle.

In the present embodiment, in the hot gas heater circuit 32 of the first embodiment, a differential pressure valve 28 is provided in the refrigerant passage from the discharge port of the refrigerant compressor 7 to the inlet of the fixed throttle 39.
Is installed. This differential pressure valve 28 is a valve body 1
02, a valve 103 arranged to be reciprocally displaceable in the valve body 102, and an adjustment spring 105 for adjusting the valve opening pressure of the valve 103 by an adjustment screw 104.
It is composed of A coolant passage 107 is formed between the outer peripheral surface of the valve 103 and the inner peripheral surface of the throttle hole 106. Further, a hook-shaped stopper 108 is formed in the valve 103. An O-ring 109 is mounted on the outer periphery of the valve 103.

The differential pressure valve 28 of the present embodiment is
Is installed in the middle of the refrigerant passage from the discharge port to the inlet of the fixed throttle 39, when the auxiliary heating operation mode is started, the throttle hole 106 is fully closed, the discharge capacity of the refrigerant compressor 7 is increased, and the valve 103 When the pressure difference before and after becomes large, that is, when the high pressure exceeds the valve opening pressure (for example, 2 kg / cm ² G) of the valve 103, the valve 103 opens and the hot gas heater circuit 32 is formed in the refrigeration cycle 5. I do.

[Other Embodiments] In the present embodiment, an example is shown in which the present invention is applied to a vehicle air conditioner provided with an air conditioning unit 1 for cooling and heating the interior of a vehicle equipped with a diesel engine (engine E). However, the present invention may be applied to a vehicle air conditioner including an air conditioning unit that cools and heats the interior of a vehicle interior of a hybrid vehicle equipped with a traveling motor and a traveling engine. Further, the present invention may be applied to an air conditioner for a vehicle including an air conditioning unit 1 for cooling and heating the cabin of a vehicle equipped with various engines having a high efficiency and a small amount of exhaust heat, such as a direct injection gasoline engine.

In this embodiment, the example of the air conditioning unit 1 in which the hot water heater 4 and the evaporator 6 are accommodated in the air conditioning duct 2 has been described, but the air conditioning unit in which only the evaporator 6 is accommodated in the air conditioning duct 2 is applied. Is also good. Further, in the present embodiment, the air-conditioning unit 1 of the air-mix temperature control type is shown, but an air-conditioning unit of the reheat type temperature control type may be applied.

In this embodiment, the external variable displacement type compressor is constituted by the refrigerant compressor 7, the electromagnetic clutch 8, the electromagnetic displacement control valve 9 and the like. Instead of providing the clutch means, it may be constituted by the refrigerant compressor 7, the electromagnetic capacity control valve 9, and the like. In this case, the refrigerant compressor 7 is directly driven by the internal combustion engine.

In the present embodiment, when the auxiliary heating operation mode is started, the hot gas heater circuit 32 is fully closed until the predetermined condition is satisfied after the refrigerant compressor 7 is started, and when the predetermined condition is satisfied, the hot gas heater circuit 32 is closed. The various valve devices are opened so as to form the refrigerant passage. However, at the time of activation of the auxiliary heating operation mode, the refrigerant passage forming the hot gas heater circuit 32 from the activation of the refrigerant compressor 7 until a predetermined condition is satisfied. May be narrowed (not fully closed) than during normal operation.

In this embodiment, when the suction pressure of the refrigerant sucked into the suction port of the refrigerant compressor 7 increases, the refrigerant compressor 7
An example in which an external variable displacement type compressor provided with an electromagnetic displacement control valve 9 for increasing the discharge capacity of the refrigerant discharged from the discharge port of the refrigerant compressor is shown. When the suction pressure increases, a variable displacement compressor having a displacement displacement means for reducing the displacement of the refrigerant discharged from the discharge port of the refrigerant compressor may be used. Also, a variable displacement compressor having a displacement displacement variable means for decreasing the displacement of the refrigerant discharged from the discharge port of the refrigerant compressor when the discharge pressure of the refrigerant discharged from the discharge port of the refrigerant compressor increases. May be used.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an air conditioning unit of a vehicle air conditioner (first embodiment).

FIG. 2 is a configuration diagram showing a refrigeration cycle of the vehicle air conditioner (first embodiment).

FIG. 3 is a sectional view showing an external variable displacement type compressor (first embodiment).

FIG. 4A is an explanatory diagram showing an operation state of an electromagnetic displacement control valve, and FIG. 4B is an explanatory diagram showing an operation state of a refrigerant compressor (first embodiment).

FIG. 5A is an explanatory diagram showing an operation state of an electromagnetic displacement control valve, and FIG. 5B is an explanatory diagram showing an operation state of a refrigerant compressor (first embodiment).

FIG. 6 is a graph showing a relationship between a control current to an electromagnetic displacement control valve and a set value of a suction pressure (first embodiment).

FIG. 7 is a block diagram showing a control system of the vehicle air conditioner (first embodiment).

FIG. 8 is a flowchart showing a blower delay control method by the air conditioner ECU (first embodiment).

FIG. 9 is a flowchart showing a discharge capacity control method by the air conditioner ECU (first embodiment).

FIG. 10 is a time chart showing a suction pressure and a discharge pressure of the refrigerant compressor (first embodiment).

FIG. 11 is a configuration diagram showing a refrigeration cycle of a vehicle air conditioner (second embodiment).

FIG. 12 is a sectional view showing a variable throttle valve (second embodiment).

FIG. 13 is a graph showing an opening degree of a variable throttle valve with respect to a high pressure of a refrigeration cycle (second embodiment).

FIG. 14 is a sectional view showing a differential pressure valve (third embodiment).

[Explanation of symbols]

REFERENCE SIGNS LIST 1 air conditioning unit 2 air conditioning duct 3 centrifugal blower 4 hot water heater (second heating heat exchanger) 5 refrigeration cycle 6 evaporator (refrigerant evaporator, first heating heat exchanger) 7 refrigerant compressor 8 electromagnetic clutch 9 electromagnetic type Capacity control valve (discharge capacity variable means) 10 Air conditioner ECU (air conditioning controller) 27 Variable throttle valve (refrigerant path throttle means) 28 Differential pressure valve (refrigerant path throttle means) 31 Normal refrigeration cycle circuit (first refrigerant circulation circuit) 32 Hot gas heater circuit (refrigerant circulation circuit, second refrigerant circulation circuit) 33 First solenoid valve (circulation circuit switching means) 34 First solenoid valve (refrigerant passage restricting means, open / close valve, circulation circuit switching means) 35 Capacitor (refrigerant condenser) 37 expansion valve (first pressure reducing device) 39 fixed throttle (second pressure reducing device) 57 suction port 85 cooling water temperature sensor (cooling water temperature detecting means) 86 refrigerant Pressure sensor (high pressure detection means) 91 Restricted hole 93 Valve element 96 Diaphragm (Valve element driving means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F25B 1/00 371 F25B 1/00 371C

Claims (8)

[Claims] (A) A refrigerant compressor which is driven to rotate by an internal combustion engine and compresses and discharges a sucked refrigerant, and adjusts a control pressure according to changes in discharge pressure and suction pressure of the refrigerant compressor. A variable capacity compressor having a discharge capacity changing means for changing a discharge capacity discharged from a discharge port of the refrigerant compressor; and (b) a refrigerant evaporator for evaporating and evaporating the inflowing refrigerant by exchanging heat with air. (C) the refrigerant discharged from the discharge port of the refrigerant compressor,
A refrigerant circulation circuit that flows directly to the refrigerant evaporator and returns to the refrigerant compressor; (d) provided in the middle of a refrigerant passage from a discharge port of the refrigerant compressor to an inlet of the refrigerant evaporator; A refrigeration cycle comprising: refrigerant passage narrowing means for narrowing a passage cross-sectional area of the refrigerant passage when a heating operation for operating a refrigerant circulation circuit is started. 2. The refrigeration cycle according to claim 1, wherein the discharge capacity variable means discharges the refrigerant from the discharge port of the refrigerant compressor when the suction pressure of the refrigerant drawn into the suction port of the refrigerant compressor increases. A refrigeration cycle characterized by increasing a discharge capacity of a refrigerant to be discharged. 3. The refrigeration cycle according to claim 1, wherein the discharge capacity variable means discharges from the discharge port of the refrigerant compressor when the suction pressure of the refrigerant drawn into the suction port of the refrigerant compressor increases. A refrigeration cycle characterized by reducing the discharge capacity of a refrigerant to be discharged. 4. The refrigeration cycle according to claim 1, wherein the discharge capacity variable means discharges the refrigerant from a discharge port of the refrigerant compressor when a discharge pressure of the refrigerant discharged from the discharge port of the refrigerant compressor increases. A refrigeration cycle characterized by reducing the discharge capacity of a refrigerant to be discharged. 5. The refrigeration cycle according to claim 1, wherein said refrigerant passage restricting means is an on-off valve for opening and closing said refrigerant circuit, and said on-off valve is said refrigerant. A refrigeration cycle, wherein the refrigerant circuit is closed until a predetermined condition is satisfied after starting the compressor. 6. The refrigeration cycle according to claim 1, wherein the refrigerant passage restricting means includes a restrictor through which a refrigerant passes, a valve body for adjusting an opening degree of the restrictor, And a variable throttle valve having a valve element driving means for decreasing the opening of the valve element as the discharge pressure of the refrigerant compressor is lower. 7. The refrigeration cycle according to claim 1, wherein said refrigerant passage restricting means closes until a discharge pressure of said refrigerant compressor becomes a predetermined value or more. A refrigeration cycle characterized by the following. 8. A vehicle air conditioner having a refrigeration cycle according to any one of claims 1 to 7, wherein the air conditioner duct accommodates the refrigerant evaporator and sends air into the vehicle interior. A blower that generates an airflow toward the vehicle interior in the air-conditioning duct; and a cooling heat source that is installed downstream of the refrigerant evaporator in the air-conditioning duct and cools the internal combustion engine. A hot water heater, a cooling water temperature detecting means for detecting a temperature of the cooling water, and an air conditioning control device for stopping the blower until the temperature of the cooling water detected by the cooling water temperature detecting means rises to a predetermined value or more. A vehicle air conditioner comprising: