Patent Publication Number: US-8973394-B2

Title: Dual evaporator unit with integrated ejector having refrigerant flow adjustability

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is based on Japanese Patent Applications No. 2009-004148 filed on Jan. 12, 2009, and No. 2009-268351 filed on Nov. 26, 2009, the contents of which are incorporated herein by reference in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to an evaporator unit, which can be suitably used for an ejector refrigerant cycle device, for example. 
     BACKGROUND OF THE INVENTION 
     An ejector refrigerant cycle device is, known in JP 2007-46806A (corresponding to U.S. Pat. No. 7,513,128B2), for example. In the refrigerant cycle device, a branch portion for branching refrigerant flowing out of a refrigerant radiator is located upstream of an ejector, such that the refrigerant of one stream branched at the branch portion flows into a nozzle portion of the ejector and the refrigerant of the other stream branched at the branch portion flows into a refrigerant suction port of the ejector. The ejector is adapted to decompress the refrigerant and to circulate the refrigerant in the refrigerant cycle device. 
     In the refrigerant cycle device, a first evaporator is located downstream of a diffuser portion of the ejector to evaporate the refrigerant flowing out of the diffuser portion of the ejector, and a throttle portion and a second evaporator are located in a refrigerant passage between the branch portion and the refrigerant suction port of the ejector so that the branched refrigerant after being decompressed in the throttle portion is evaporated by the second evaporator. Therefore, cooling and refrigerating capacity can be obtained in both the first evaporator and the second evaporator. 
     Furthermore, in the refrigerant cycle device, a gas-liquid separator is located in the branch portion to adjust the dryness of the refrigerant, so that gas refrigerant separated in the gas-liquid separator flows into the nozzle portion of the ejector and liquid refrigerant separated in the gas-liquid separator flows into the refrigerant passage in which the throttle portion and the second evaporator are located. The liquid refrigerant is separated at the gas-liquid separator in a centrifugal manner or a weight manner. 
     However, JP 2007-46806A does not describe regarding the assemble structure of the components in the refrigerant cycle device, and, thereby mounting performance of the refrigerant cycle device to a vehicle may be deteriorated based on the assemble structure of the components. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing problems, it is an object of the present invention to provide an evaporator unit provided with a flow amount distributor and an ejector, which are arranged in line in a longitudinal direction of the ejector. 
     It is another object of the present invention to provide an evaporator unit in which plural components are integrally assembled for a refrigerant cycle device, thereby improving mounting performance of the refrigerant cycle device. 
     According to an aspect of the present invention, an evaporator unit for a refrigerant cycle device includes: an ejector that is provided with a nozzle portion configured to decompress refrigerant and a refrigerant suction port from which, refrigerant is drawn by a high-speed refrigerant flow jetted from the nozzle portion, and is configured such that the refrigerant jetted from the nozzle portion and the refrigerant drawn from the refrigerant suction port are mixed and the mixed refrigerant is discharged from an outlet of the ejector; a first evaporator coupled to the outlet of the ejector to evaporate the refrigerant flowing out of the outlet of the ejector; a second evaporator coupled to the refrigerant suction port to evaporate the refrigerant to be drawn into the ejector from the refrigerant suction port; a flow amount distributor that is connected to a refrigerant inlet side of the nozzle portion, is located at a position upstream of the second evaporator in a refrigerant flow, and is configured to adjust a flow amount of the refrigerant distributed to the nozzle portion and a flow amount of the refrigerant distributed to the second evaporator; and a throttle mechanism provided between the flow amount distributor and the second evaporator to decompress the refrigerant flowing into the second evaporator. In the evaporator unit, the ejector, the first evaporator, the second evaporator, the flow amount distributor and the throttle mechanism are assembled integrally. The flow amount distributor is adapted as both of a gas-liquid separation portion separating the refrigerant flowing therein into gas refrigerant and liquid refrigerant, and a refrigerant distribution portion for distributing the separated refrigerant into the nozzle portion and the second evaporator. Furthermore, in the evaporator unit, the flow amount distributor and the ejector are arranged in line in a longitudinal direction of the ejector. Accordingly, mounting performance of the refrigerant cycle device including the evaporator unit can be improved. 
     For example, the first and second evaporators may be arranged adjacent to each other in an air flow direction, and each of the first evaporator and the second evaporator may include a plurality of tubes in which the refrigerant flows and a tank disposed at one end side of the tubes and extending in a tank longitudinal direction to distribute the refrigerant into the tubes or to collect the refrigerant from the tubes. In this case, the ejector, the flow amount distributor and the throttle mechanism may be assembled to an outer surface of the tanks of the first and second evaporators on a side opposite to the tubes. 
     Furthermore, the tank of the first evaporator may be provided with a first refrigerant distribution tank portion in which the refrigerant flowing out of the ejector is distributed into the tubes of the first evaporator, and the tank of the second evaporator may be provided with a second refrigerant distribution tank portion in which the refrigerant decompressed by the throttle mechanism is distributed into the tubes of the second evaporator. In this case, the evaporator unit may further include a refrigerant storage member located in at least one of the first and second refrigerant distribution tank portions to store the liquid refrigerant, and the refrigerant storage member may be configured such that the refrigerant overflowing from the refrigerant storage member flows into the tubes. 
     The ejector, the first evaporator, the second evaporator, the flow amount distributor and the throttle mechanism may be brazed as an integrated unit. 
     Alternatively/Further, the evaporator unit may be further provided with an ejector case in which the ejector is accommodated. In this case, the ejector, the first evaporator, the second evaporator, the flow amount distributor, the throttle mechanism and the ejector case can be assembled integrally. Furthermore, the ejector, the first evaporator, the second evaporator, the flow amount distributor, the throttle mechanism and the ejector case may be assembled to an outer surface of the tanks of the first and second evaporators, on a side opposite to the tubes. 
     The flow amount distributor may have a cylindrical outer wall surface, and the ejector case may have a cylindrical outer wall surface. In this case, the cylindrical outer wall surface of the flow amount distributor and the cylindrical outer wall surface of the ejector case may be arranged in line to continuously extend in the longitudinal direction of the ejector. 
     In the above any evaporator unit, the throttle mechanism may be a taper-straight combination nozzle having approximately a funnel shape. In this case, the taper-straight combination nozzle can be configured by a taper portion in which an inner diameter is reduced as toward downstream in a refrigerant flow, and a straight portion having a constant inner diameter and extending from a downstream end of the taper portion. 
     Alternatively, the flow amount distributor may be configured to have a cylindrical space portion extending in a horizontal direction, a first outlet port provided at an axial end portion of the cylindrical space portion such that the refrigerant in the cylindrical space portion flows toward the nozzle portion via the first outlet port, and a second outlet port provided in a cylindrical wall surface of the cylindrical space portion such that the refrigerant in the cylindrical space portion flows toward the throttle mechanism via the second outlet port. In this case, the second outlet port may be provided at a position lower than the first outlet port, or/and the nozzle portion may have an inlet port that is directly connected to the first outlet port, or/and the throttle mechanism may be directly connected to the second outlet port. Furthermore, the flow amount distributor may be configured such that the refrigerant flows in the cylindrical space portion to be swirled therein. 
     Alternatively, the flow amount distributor may include a cylindrical wall portion defining a cylindrical space portion, the cylindrical wall portion may be configured by a plurality layers overlapped with other, and the throttle mechanism may be configured by a helical groove provided between adjacent layers of the cylindrical wall portion. Because the throttle mechanism can be located inside the flow amount distributor, the entire size of the evaporator unit can be further reduced. 
     Alternatively, the flow amount distributor may include a cylindrical wall portion defining therein a cylindrical space portion, a swirl generating portion configured to generate a swirl movement in the refrigerant flowing from an inlet port into the cylindrical space portion, and the throttle mechanism may be provided in the cylindrical wall portion. 
     Furthermore, the ejector may include a body member for defining a mixing portion in which the refrigerant jetted from the nozzle portion and the refrigerant drawn from the refrigerant suction portion are mixed and for defining a diffuser portion in which a pressure of the mixed refrigerant is increased by converting speed energy of the mixed refrigerant to pressure energy thereof, and the nozzle portion may be configured by a nozzle forming member. In this case, the nozzle forming member may be provided in the body member, and the cylindrical wall portion of the flow amount distributor may be molded integrally with the body member. Furthermore, the cylindrical wall portion of the flow amount distributor may be configured by a plurality of layers overlapped with each other, and the throttle mechanism may be provided between adjacent layers in the cylindrical wall portion of the flow amount distributor. 
     Alternatively, the ejector may include a body member for defining a mixing portion in which the refrigerant jetted from the nozzle portion and the refrigerant drawn from the refrigerant suction portion are mixed and for defining a diffuser portion in which a pressure of the mixed refrigerant is increased by converting speed energy of the mixed refrigerant to pressure energy thereof, and the nozzle portion may be configured by a nozzle forming member integrated with the body member. In this case, the flow amount distributor may be configured by the nozzle forming member at a position, upstream of the nozzle portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional objects and advantages of the present invention will be more readily apparent from the following detailed description of preferred embodiments when taken together with the accompanying drawings. In which: 
         FIG. 1A  is a schematic diagram showing a refrigerant cycle device with an ejector, and  FIG. 1B  is a diagram showing the relationship between a pressure and an enthalpy in a refrigerant cycle of the refrigerant cycle device, according to a first embodiment of the present invention; 
         FIG. 2  is a disassembled perspective view showing a schematic structure of an evaporator unit for the refrigerant-cycle device according to the first embodiment; 
         FIG. 3  is a schematic perspective view showing the evaporator unit according to the first embodiment; 
         FIG. 4  is a schematic sectional view showing a part of the evaporator unit at a position near a flow amount distributor, according to the first embodiment; 
         FIG. 5A  is a schematic diagram showing examples of a throttle mechanism, and  FIG. 5B  is a graph showing relationships between a refrigerant flow amount and an inlet dryness of the throttle mechanism in plural examples E 1 , E 2  and E 3  of the throttle mechanism shown in  FIG. 5A ; 
         FIG. 6A  is schematic perspective view showing a flow amount distributor and a throttle mechanism according to according to a second embodiment of the present invention, and  FIG. 6B  is cross-sectional view taken along the line VIB-VIB of  FIG. 6A ; 
         FIGS. 7A and 7B  are perspective view and side view, showing a flow amount distributor and a throttle mechanism according to a third embodiment of the present invention; 
         FIGS. 8A and 8B  are cross-sectional view and perspective view, showing a flow amount distributor and a throttle mechanism according to a fourth embodiment of the present invention; 
         FIGS. 9A and 9B  are front view and perspective view, showing a flow amount distributor and a throttle mechanism according to a fifth embodiment of the present invention; 
         FIG. 10  is a cross-sectional view showing a flow amount distributor and a throttle mechanism according to according to a sixth embodiment of the present invention; 
         FIG. 11  is a disassembled perspective view showing a schematic structure of an evaporator unit for a refrigerant cycle device according to a seventh embodiment of the present invention; 
         FIG. 12A  is a cross sectional view showing a part of a tank portion of the evaporator unit of  FIG. 11 , and  FIG. 12B  is a cross-sectional view showing a part of the tank portion with a flow amount distributor, according to the seventh embodiment; 
         FIG. 13A  is a cross sectional view showing a part of a tank portion for an evaporator unit, and  FIG. 13B  is a cross-sectional view showing a part of the tank portion with a flow amount distributor, according to a first modification example of the seventh embodiment; 
         FIG. 14A  is a cross sectional view showing a part of a tank portion for an evaporator unit, and  FIG. 14B  is a cross-sectional view showing a part of the tank portion with a flow amount distributor, according to a second modification example of the seventh embodiment; 
         FIG. 15A  is a cross sectional view showing a part of a tank portion for an evaporator unit, and  FIG. 15B  is a cross-sectional view showing a part of the tank portion with a flow amount distributor, according to a third modification example of the seventh embodiment; 
         FIG. 16A  is a cross sectional view showing a part of a tank portion for an evaporator unit, and  FIG. 16B  is a cross-sectional view showing a part of the tank portion with a flow amount distributor, according to a fourth modification example of the seventh embodiment; 
         FIGS. 17A and 17B  are cross-sectional views showing an ejector integrated with a flow amount distributor, according to an eighth embodiment of the present invention; 
         FIG. 18  is an enlarged sectional view showing the flow amount distributor shown in  FIGS. 17A and 17B ; 
         FIG. 19  is a cross-sectional view showing a flow amount distributor according to a modification example of the eighth embodiment; 
         FIGS. 20A and 20B  are cross-sectional views showing examples of a flow amount distributor according to a ninth embodiment of the present invention; 
         FIG. 21  is a perspective view showing a part of an ejector and a flow amount distributor integrated with the ejector, according to a tenth embodiment of the present invention; 
         FIGS. 22A and 22B  are cross-sectional views showing an ejector and a flow amount distributor provided in the ejector, according to an eleventh embodiment of the present invention; 
         FIGS. 23A and 23B  are cross-sectional views each showing an ejector and a flow amount distributor provided in the ejector, according to a twelfth embodiment of the present invention; and 
         FIGS. 24A to 24D  are schematic diagrams showing examples of a refrigerant cycle device with an ejector and a flow amount distributor provided in the ejector, according to the twelfth embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
     A first embodiment of the present invention will be described below with reference to  FIGS. 1A to 5B . In the present embodiment, an evaporator unit of the present invention will be typically used for a refrigerant cycle device. The evaporator unit for the refrigerant cycle device is an integrated evaporator unit in which plural components of a refrigerant cycle, such as an evaporator, an ejector and a flow amount distributor, are integrally disposed. 
     The integrated evaporator unit is connected to other components of the refrigerant cycle, including a condenser, a compressor, and the like, via piping to constitute a refrigerant cycle device with an ejector. The integrated evaporator unit of the embodiment is used for an indoor equipment (e.g., evaporator) for cooling air. The integrated evaporator unit may be used as an outdoor equipment in other embodiments. 
       FIG. 1A  shows an example of an ejector refrigerant cycle device  10  for a vehicle according to the first embodiment, and  FIG. 1B  is a Mollier diagram showing the relationship between a pressure and an enthalpy in the ejector refrigerant cycle device  10  in  FIG. 1A . 
     In the Mollier diagram shown in  FIG. 1B , the solid line indicates the operation state of the ejector refrigerant cycle device  10  of the present embodiment, and the chain line indicates the operation state of a comparative refrigerant cycle device without an ejector, in which refrigerant is circulated in this order of a compressor, a condenser, an expansion valve, an evaporator and the compressor. 
     In the ejector refrigerant cycle device  10  of  FIG. 1A , a compressor  11  for drawing and compressing refrigerant is driven by an engine for vehicle traveling (not shown) via an electromagnetic clutch  11   a , a belt, or the like. 
     As the compressor  11 , may be used either a variable displacement compressor which can adjust a refrigerant discharge capability by a change in discharge capacity, or a fixed displacement compressor which can adjust a refrigerant discharge capability by changing an operating ratio of the compressor through engagement and disengagement of the electromagnetic clutch  11   a . If an electric compressor is used as the compressor  11 , the refrigerant discharge capability can be adjusted or regulated by adjustment of the number of revolutions of an electric motor. 
     A refrigerant radiator  12  is disposed at a refrigerant discharge side of the compressor  11 . The radiator  12  exchanges heat between the high-pressure refrigerant discharged from the compressor  11  and an outside air (i.e., air outside a compartment of a vehicle) blown by a cooling fan (not shown), thereby to cool the high-pressure refrigerant. 
     As the refrigerant for the ejector refrigerant cycle device  10  in the embodiment, is used a refrigerant whose high pressure does not exceed a critical pressure, such as a flon-based refrigerant, or a HC-based refrigerant, so as to form a vapor-compression subcritical cycle. Thus, the radiator  12  serves as a condenser for cooling and condensing the refrigerant therein. 
     A thermal expansion valve  13  is disposed at a refrigerant outlet side of the radiator  12 . The thermal expansion valve  13  is a decompression unit for decompressing the refrigerant flowing from the radiator, and includes a temperature sensing part  13   a  disposed in a refrigerant suction passage of the compressor  11 . 
     The thermal expansion valve  13  detects a degree of superheat of the refrigerant at the compressor suction side based on the temperature or/and pressure of the suction side refrigerant of the compressor  11 , and adjusts a valve opening degree (i.e., refrigerant flow amount) such that the superheat degree of the refrigerant on the compressor suction side becomes a predetermined value which is preset, as is known generally in the art. 
     An ejector  14  is disposed at a refrigerant outlet side of the thermal expansion valve  13 . The ejector  14  is adapted as decompression means for decompressing the refrigerant as well as refrigerant circulating means (kinetic vacuum pump) for circulating the refrigerant by a suction effect (entrainment effect) of the refrigerant flow ejected at high speed. 
     The ejector  14  includes a nozzle portion  14   a  for further decompressing and expanding the refrigerant (i.e., the middle-pressure refrigerant) by restricting a path area of the refrigerant having passed through the thermal expansion valve  13  to a small level, and a refrigerant suction port  14   b  provided in the same space as a refrigerant jet port of the nozzle portion  14   a , for drawing the vapor-phase refrigerant flowing from a second evaporator  18  as described later. 
     A mixing portion  14   c  is provided in the ejector  14  on the downstream side part of the nozzle portion  14   a  and the refrigerant suction portion  14   b  in the refrigerant flow, for mixing a high-speed refrigerant flow jetted from the nozzle portion  14   a  and a drawn refrigerant from the refrigerant suction port  14   b . A diffuser portion  14   d  serving as a pressure-increasing portion is provided on the downstream side of the refrigerant flow of the mixing portion  14   c  in the ejector  14 . The diffuser portion  14   d  is formed in such a manner that a path area of the refrigerant is generally increased toward downstream from the mixing portion  14   c . The diffuser portion  14   d  serves to increase the refrigerant pressure by decelerating the refrigerant flow, that is, to convert the speed energy of the refrigerant into the pressure energy. 
     A first evaporator  15  is connected to an outlet (the tip end of the diffuser portion  14   d ) of the ejector  14 . The refrigerant outlet side of the first evaporator  15  is connected to a suction side of the compressor  11 . 
     A flow amount distributor  16  is located at a refrigerant outlet side of the thermal expansion valve  13 , so as to adjust a refrigerant flow amount Gn flowing into the nozzle portion  14   a  of the ejector  14  and a refrigerant flow amount Ge flowing into the refrigerant suction port  14   b  of the ejector  14  via the second evaporator  18 . 
     The flow amount distributor  16  includes an inlet port  16   a , a first outlet port  16   b  and a second outlet port  16   c . The inlet port  16   a  of the flow amount distributor  16  is connected to an outlet side of the thermal expansion valve  13 , so that the refrigerant flowing out of the thermal expansion valve  13  flows into the flow amount distributor  16  from the inlet port  16   a . The first outlet port  16   b  of the flow amount distributor  16  is connected to an inlet side of the nozzle portion  14   a  so that the refrigerant flowing out of the first outlet port  16   b  flows into the nozzle portion  14   a  of the ejector  14 . The second outlet port  16   c  of the flow amount distributor  16  is coupled to refrigerant suction port  14   b  of the ejector  14  so that the refrigerant flowing out of the second outlet port  16   c  of the flow amount distributor  16  flows to be drawn into the refrigerant suction port  14   b  of the ejector  14 . 
     A throttle mechanism  17  and a second evaporator  18  is disposed in a refrigerant passage between the second outlet port  16   c  of the flow amount distributor  16  and the refrigerant suction port  14   b  of the ejector  14 . The throttle mechanism  17  is disposed upstream of the second evaporator  18  in a refrigerant flow. The throttle mechanism  17  serves as a decompression unit which performs a function of adjusting a refrigerant flow amount into the second evaporator  18 . More specifically, the throttle mechanism  17  can be configured by a fixed throttle, such as a capillary tube, or an orifice. 
     In the first embodiment, both the first and second evaporators  15  and  18  are incorporated into an integrated structure with an arrangement as described later. The two evaporators  15  and  18  are accommodated in a case not shown, and air (air to be cooled) is blown by a common electric blower  19  through an air passage formed in the case in the direction of an arrow F 1 , so that the blown air is cooled by the two evaporators  15  and  18 . 
     The cooled air by the two evaporators  15  and  18  is fed to a common space to be cooled (not shown). This causes the two evaporators  15  and  18  to cool the common space to be cooled. Among these two evaporators  15  and  18 , the first evaporator  15  connected to a main stream path on the downstream side of the ejector  14  is disposed on the upstream side (upwind side) of the air flow F 1 , while the second evaporator  18  connected to the refrigerant suction port  14   b  of the ejector  14  is disposed on the downstream side (downwind side) of the air flow F 1 . 
     When the ejector refrigerant cycle device  10  of the embodiment is used as a refrigerant cycle device for a vehicle air conditioner, the space within the vehicle compartment is a space to be cooled. When the ejector refrigerant cycle device  10  of the embodiment is used for a refrigerant cycle device for a freezer car, the space within the freezer and refrigerator of the freezer car is the space to be cooled. 
     In the embodiment, the ejector  14 , the first and second evaporators  15  and  18 , and the throttle mechanism  17  are incorporated into one integrated evaporator unit  20 . Now, specific examples of the integrated evaporator unit  20  will be described below in detail with reference to  FIGS. 2 to 4 .  FIG. 2  is a disassembled perspective view showing the entire schematic structure of the integrated evaporator unit  20 ,  FIG. 3  is a perspective view showing the integrated evaporator unit  20 , and  FIG. 4  is a schematic cross-sectional view showing examples of the flow amount distributor  16  of the integrated evaporator unit  20 . In  FIGS. 2 to 4 , the top-bottom direction indicates the top-bottom direction of the integrated evaporator unit  20  when being mounted to a vehicle. In  FIG. 3 , the indication of the ejector  14  is omitted. 
     First, an example of the integrated structure including the two evaporators  15  and  18  will be explained below with reference to  FIGS. 2 and 3 . In the embodiment, the two evaporators  15  and  18  can be formed integrally into a completely single evaporator structure. Thus, the first evaporator  15  constitutes an upstream side area of the single evaporator structure in the direction of the air flow F 1 , while the second evaporator  18  constitutes a downstream side area of the single evaporator structure in the direction of the air flow F 1 . 
     The first evaporator  15  and the second evaporator  18  have the same basic structure, and include heat exchange cores  15   a  and  18   a , and tanks  15   b ,  15   c ,  18   b , and  18   c  positioned on both upper and lower sides of the heat exchange cores  15   a  and  18   a , respectively, to extend horizontal directions (i.e., tank longitudinal directions). 
     The heat exchanger cores  15   a  and  18   a  respectively include a plurality of tubes  21  extending in a tube longitudinal direction. The tube  21  corresponds to a heat source fluid passage in which a heat source fluid for performing a heat exchange with a heat-exchange medium flows. One or more passages for allowing a heat-exchange medium, namely air to be cooled in the embodiment, to pass therethrough are formed between the tubes  21 . 
     Between these tubes  21 , fins  22  are disposed, so that the tubes  21  can be connected to the fins  22 . Each of the heat exchange cores  15   a  and  18   a  is constructed of a laminated structure of the tubes  21  and the fins  22 . The tubes  21  and the fins  22  are alternately laminated in a lateral direction of the heat exchange cores  15   a  and  18   a . In other embodiments or examples, any appropriate structure without using the fins  22  in the heat exchange cores  15   a  and  18   a  may be employed. 
     In  FIGS. 2 and 3 , only some of the fins  22  are shown, but in fact the fins  22  are disposed over the whole areas of the heat exchange cores  15   a  and  18   a , and the laminated structure including the tubes  21  and the fins  22  is disposed over the whole areas of the heat exchange cores  15   a  and  18   a . The blown air by the electric blower  19  is adapted to pass through voids (clearances) in the laminated structure of the heat exchange cores  15   a ,  18   a.    
     The tube  21  constitutes the refrigerant passage through which refrigerant flows, and is made of a flat tube having a flat cross-sectional shape in the air flow direction F 1 . The fin  22  is a corrugated fin made by bending a thin plate in a wave-like shape, and is connected to a flat outer surface of the tube  21  to expand a heat transfer area of the air side. 
     The tubes  21  of the heat exchanger core  15   a  and the tubes  21  of the heat exchanger core  18   a  independently constitute the respective refrigerant passages. The tanks  15   b  and  15   c  on both the upper and lower sides of the first evaporator  15 , and the tanks  18   b  and  18   c  on both the upper and lower sides of the second evaporator  18  independently constitute the respective refrigerant passage spaces (i.e., tank spaces). 
     Each of the tanks  15   b ,  15   c ,  18   b ,  18   c  of the first and second evaporators  15 ,  18  extends in an arrangement direction (stack direction) of the tubes  21 . For example, in  FIGS. 2 and 3 , the arrangement direction of the tubes  21  is the left and right direction, which is perpendicular to the air flow direction F 1 . 
     The tanks  15   b  and  15   c  on both the upper and lower sides of the first evaporator  15  have tube fitting holes (not shown) into which upper and lower ends of the tube  21  of the heat exchange core  15   a  are inserted and fitted, so that both the upper and lower ends of the tube  21  are communicated with the inside space of the tanks  15   b  and  15   c , respectively. 
     Similarly, the tanks  18   b  and  18   c  on both the upper and lower sides of the second evaporator  18  have tube fitting holes (not shown) into which upper and lower ends of the tube  21  of the heat exchange core  18   a  are inserted and fitted, so that both the upper and lower ends of the tube  21  are communicated with the inside space of the tanks  18   b  and  18   c , respectively. 
     Thus, the tanks  15   b ,  15   c ,  18   b  and  18   c  disposed on both the upper and lower sides serve to distribute the refrigerant streams to the respective tubes  21  of the heat exchange cores  15   a  and  18   a , and to collect the refrigerant streams from these tubes  21 . 
     Since the two upper tanks  15   b  and  18   b  are adjacent to each other, the two upper tanks  15   b  and  18   b  can be molded integrally. The same can be made for the two lower tanks  15   c  and  18   c . It is apparent that the two upper tanks  15   b  and  18   b  may be molded independently as independent components, and that the same can be made for the two lower tanks  15   c  and  18   c.    
     Material suitable for use in the evaporator components, such as the tube  21 , the fin  22 , the tanks  15   b ,  15   c ,  18   b , and  18   c , may include, for example, aluminum, which is metal with excellent thermal conductivity and brazing property. By forming each component using the aluminum material, the entire structures of the first and second evaporators  15  and  18  can be assembled, integrally with brazing. 
     In the embodiment, the ejector  14 , the flow amount distributor  16  and the throttle mechanism  17  are arranged on a wall surface of the upper tanks  15   b ,  18   b , at a side opposite to the tubes  21 . In the example of  FIGS. 2 and 3 , the ejector  14 , the flow amount distributor  16  and the throttle mechanism  17  are arranged on an upper side in the upper tanks  15   b ,  18   b.    
     The ejector  14  is formed into a thin elongated shape extending in an axial direction of the nozzle portion  14   a , and is arranged on the upper tanks  15   b ,  18   b  such that the longitudinal direction of the ejector  14  is approximately in parallel with the tank longitudinal direction. In the present embodiment, a cylindrical ejector case  23  is provided on the upper tanks  15   b ,  18   b  so that the ejector  14  is disposed on the upper tanks  15   b ,  18   b  in a state accommodated in the ejector case  23 . 
     The flow amount distributor  16  is formed into a cylindrical shape extending in the tank longitudinal direction (e.g., horizontal direction in  FIGS. 2 and 3 ), so as to form therein a cylindrical space  16   d  extending in the tank longitudinal direction. The inlet port  16   a  is opened at one end portion (e.g., left end portion in  FIGS. 2 and 3 ) of the flow amount distributor  16  in the extending direction, the first outlet port  16   b  opened at the other end portion (e.g., right end portion in  FIGS. 2 and 3 ) of the flow amount distributor  16  in the extending direction, and the second outlet port  16   c  is opened at a cylindrical wall surface of the flow amount distributor  16  toward in a radial direction of the cylindrical shape. 
     The flow amount distributor  16  is located at an inlet side of the nozzle portion  14   a  of the ejector  14 . As shown in  FIG. 2 , the nozzle portion  14   a  is directly connected to the first outlet port  16   b . In the present embodiment, the flow amount distributor  16  and the ejector  14  are arranged in line in the longitudinal direction of the ejector  14  in series. Furthermore, the flow amount distributor  16  and an ejector case  23  are formed into a cylindrical shape having a constant outer diameter extending coaxially. That is, the cylindrical outer surface of the flow amount distributor  16  and the cylindrical outer surface of the ejector case  23  continuously extend to form a single cylindrical shape on the upper tanks  15   b ,  18   b.    
     In the present embodiment, the throttle mechanism  17  is directly connected to the second outlet port  16   c , and protrudes from the cylindrical outer surface of the flow amount distributor  16  radially outside into the upper tank  18   b.    
     The components of the evaporators  15 ,  18 , such that the tubes  21 , the fins  22 , the tanks  15   b ,  15   c ,  18   b ,  18   c  and the like, can be made of a metal having sufficient heat contacting performance and brazing performance, such as an aluminum. Each of the components of the evaporators  15 ,  18  can be molded by using aluminum. The temporally assembled structure of the evaporators  15 ,  18  are integrally brazed. 
     The ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the ejector case  23  can be made of aluminum. In this case, the ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the ejector case  23  may be integrated with the first and second evaporators  15 ,  18  by brazing so as to form the integrated evaporator unit  20 . 
     The ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the ejector case  23  may be made of a material other than aluminum. For example, the ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the ejector case  23  may be made of resin. In this case, the ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the ejector case  23  can be suitably fixed to the first and second evaporators  15 ,  18  by using a fixing means such as screwing, so as to form the integrated evaporator unit  20 . 
     The integrated evaporator unit  20  is provided with a single refrigerant inlet  24  and a single refrigerant outlet  25 , which are located at one longitudinal end portion (e.g., left end portion in  FIGS. 2 and 3 ) of the upper tanks  15   b ,  18   b  of the first and second evaporators  15 ,  18 . As shown in  FIG. 2 , the refrigerant inlet  24  is made to communicate with the inlet port  16   a  of the flow amount distributor  16 , the refrigerant outlet  25  is made to communicate with the upper tank  15   b  of the first evaporator  15 . 
     A partition plate  28  is located in the inner space of the upper tank  15   b  of the first evaporator  15  at an approximate center in the longitudinal direction, to partition the inner space of the upper tank  15   b  of the first evaporator  15  into a first tank space  26  at one side in the longitudinal direction and a second tank space  27  at the other side in the longitudinal direction. The partition plate  28  is fixed to an inner wall surface of the upper tank  15   b  by brazing, for example. 
     The first tank space  26  is adapted as a refrigerant collection tank portion into which the refrigerant having passed through the tubes  21  of the first evaporator  15  is collected, and the second tank space  27  is adapted as a refrigerant distribution tank portion from which the refrigerant is distributed into the tubes  21  of the first evaporator  15 . 
     A partition plate  31  is located in the inner space of the upper tank  18   b  of the second evaporator  18  at an approximate center in the longitudinal direction, to partition the inner space of the upper tank  18   b  of the second evaporator  18  into a first tank space  29  at one side in the longitudinal direction and a second tank space  30  at the other side in the longitudinal direction. The partition plate  31  is fixed to an inner wall surface of the upper tank  18   b  by brazing, for example. 
     The first tank space  29  is adapted as a refrigerant distribution tank portion from which the refrigerant is distributed into the tubes  21  of the second evaporator  18 , the second tank space  30  is adapted as a refrigerant collection tank portion into which the refrigerant having passed through the tubes  21  of the second evaporator  18  is collected. 
     The ejector downstream tip end (e.g., the right end portion in  FIG. 2 ) is configured to form an outlet portion of the ejector  14 , and is open into an inner space of the ejector case  23 . The inner space of the ejector case  23  is made to communicate with the second inner space  27  of the upper tank  15   b , so that the refrigerant flowing out of the outlet portion of the ejector  14  flows into the second tank space  27  in the upper tank  15   b  via the inner space of the ejector case  23 . The refrigerant suction port  14   b  of the ejector  14  is made to communicate with the second tank space  30  of the upper tank  18   b  of the second evaporator  18 . 
     Next, refrigerant flow passages in the entire integrated evaporator unit  20  will be described. The flow of the refrigerant flowing into the flow amount distributor  16  from the refrigerant inlet  24  is branched into a main stream of the refrigerant flowing toward the nozzle portion  14   a  of the ejector  14  and a branch stream of the refrigerant flowing toward the throttle mechanism  17 , as shown in  FIG. 2 . 
     The refrigerant of the main stream flowing toward the nozzle portion  14   a  of the ejector  14  passes through the ejector  14  (i.e., the nozzle portion  14   a →the mixing portion  14   c →the diffuser portion  14   d ) and is decompressed. The decompressed low-pressure refrigerant flowing out of the ejector  14  flows into the second tank space  27  of the upper tank  15   b  of the first evaporator  15 , via the inner space of the ejector case  23  as in the direction of the arrow R 1 . 
     The refrigerant in the second tank space  27  moves downward in the tubes  21  positioned at the right side portion in the heat exchange core  15   a  as shown in the direction of the arrow R 2 , so as to flow into the right side part of the lower tank  15   c . Within the lower tank  15   c , a partition plate is not provided, and thus the refrigerant moves from the right side of the lower tank  15   c  to the left side thereof in the direction of the arrow R 3 . 
     The refrigerant at the left side part in the lower tank  15   c  moves upward in the tubes  21  positioned on the left side of the heat exchange core  15   a  in the direction of the arrow R 4  to flow into the first tank space  26  of the upper tank  15   b . The refrigerant further flows to the refrigerant outlet  25  in the direction of the arrow R 5 . 
     In contrast, the refrigerant of the branch stream flowing toward the throttle mechanism  17  in the cylindrical space  16   d  of the flow amount distributor  16  is decompressed by the throttle mechanism  17 , and then the decompressed low-pressure refrigerant (liquid-gas two-phase refrigerant) flows into the first tank space  29  of the upper tank  18   b  of the second evaporator  18  in the direction of the arrow R 6 . 
     The refrigerant flowing into the first tank space  29  of the upper tank  18   b  of the second evaporator  18  moves downward in the tubes  21  positioned on the left side of the heat exchange core  18   a  in the direction of the arrow R 7  to flow into the left side part of the lower tank  18   c . Within the lower tank  18   c , a right and left partition plate is not provided, and thus the refrigerant moves from the left side of the lower tank  18   c  to the right side thereof in the direction of an arrow R 8 . 
     The refrigerant on the right side of the lower tank  18   c  moves upward in the tubes  21  positioned on the right side of the heat exchange core  18   a  in the direction of the arrow R 9  to flow into the second tank space  30  of the upper tank  18   b . Since the refrigerant suction port  14   b  of the ejector  14  is in communication with the second tank space  30  of the upper tank  18   b  of the second evaporator  18 , the refrigerant in the second tank space  30  is drawn from the refrigerant suction port  14   b  into the ejector  14 . 
     The integrated evaporator unit  20  has the structure of the refrigerant passages as described above. The integrated evaporator unit  20  can be configured to have the single refrigerant inlet  24  and the single refrigerant outlet  25 , in the whole of the integrated evaporator unit  20 . 
     Now, an operation of the ejector refrigerant cycle device  10  of the first embodiment will be described. When the compressor  11  is driven by a vehicle engine via the electromagnetic clutch  11   a , the high-temperature and high-pressure refrigerant compressed by and discharged from the compressor  11  flows into the radiator  12 , so that the high-temperature refrigerant is cooled and condensed by the outside air. The high-pressure refrigerant flowing from the radiator  12  passes through the thermal expansion valve  13 . 
     The thermal expansion valve  13  adjusts the degree of valve opening (refrigerant flow amount) such that the superheat degree of the refrigerant at the outlet of the first evaporator  15  (i.e., drawn refrigerant by the compressor  11 ) becomes a predetermined value, and the high-pressure refrigerant is decompressed by the thermal expansion valve  13 . The refrigerant having passed through the thermal expansion valve  13  (middle pressure refrigerant) flows into the refrigerant inlet  24  provided in the integrated evaporator unit  20 , and further flows into the cylindrical space  16   d  of the flow amount distributor  16  from the inlet port  16   a.    
     The refrigerant flow in the cylindrical space  16   d  of the flow amount distributor  16  is branched into the main stream of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  via the first outlet port  16   b , and the branch stream of the refrigerant flowing into the throttle mechanism  17  via the second outlet port  16   c.    
     The refrigerant flowing into the ejector  14  is decompressed and expanded by the nozzle portion  14   a . Thus, the pressure energy of the refrigerant is converted into the speed energy at the nozzle portion  14   a , and the refrigerant is ejected from the jet port of the nozzle portion  14   a  at high speed. At this time, the pressure drop of the refrigerant is caused at the jet port of the nozzle portion  14   a , thereby drawing from the refrigerant suction port  14   b , the refrigerant (vapor-phase refrigerant) of the branch stream having passed through the second evaporator  18 . 
     The refrigerant ejected from the nozzle portion  14   a  and the refrigerant drawn into the refrigerant suction port  14   b  are joined and mixed by the mixing portion  14   c  on the downstream side of the nozzle portion  14   a , and then flows into the diffuser portion  14   d . In the diffuser portion  14   d , the speed (expansion) energy of the refrigerant is converted into the pressure energy by enlarging the path area, resulting in increased pressure of the refrigerant. 
     The refrigerant flowing out of the diffuser portion  14   d  of the ejector  14  flows through the refrigerant flow passages indicated by the arrows R 1  to R 5  in  FIG. 2 , in the first evaporator  15 . During this time, in the heat exchange core  15   a  of the first evaporator  15 , the low-temperature and low-pressure refrigerant absorbs heat from the blown air in the direction of the arrow F 1  so as to be evaporated. The vapor-phase refrigerant evaporated is drawn from the single refrigerant outlet  25  into the compressor  11 , and is compressed again by the compressor  11 . 
     The refrigerant of the branch stream flowing from the second outlet port  16   c  of the flow amount distributor  16  toward the throttle mechanism  17  is decompressed by the throttle mechanism  17  to become a low-pressure refrigerant (e.g., liquid-gas two-phase refrigerant). The low-pressure refrigerant flows through the refrigerant flow passages indicated by the arrows R 6  to R 9  of  FIG. 2  in the second evaporator  18 . During this time, in the heat exchange core  18   a  of the second evaporator  18 , the low-temperature and low-pressure refrigerant absorbs heat from the blown air having passed through the first evaporator  15  to be evaporated. The vapor-phase refrigerant evaporated in the second evaporator  18  is drawn from the refrigerant suction port  14   b  into the ejector  14 . 
     As described above, according to the embodiment, the refrigerant on the downstream side of the diffuser portion  14   d  of the ejector  14  can be supplied to the first evaporator  15 , and the refrigerant on the branch stream can be supplied to the second evaporator  18  via the throttle mechanism  17 , so that the first and second evaporators  15  and  18  can exhibit cooling effects at the same time. Thus, the cooled air by both the first and second evaporators  15  and  18  can be blown into a space to be cooled, thereby cooling the space to be cooled. 
     At that time, the refrigerant evaporation pressure of the first evaporator  15  is the pressure of the refrigerant which has been increased by the diffuser portion  14   d . In contrast, since the outlet side of the second evaporator  18  is connected to the refrigerant suction port  14   b  of the ejector  14 , the lowest pressure of the refrigerant which has been decompressed at the nozzle portion  14   a  can act on the second evaporator  18 . 
     Thus, the refrigerant evaporation pressure (refrigerant evaporation temperature) of the second evaporator  18  can be lower than the refrigerant evaporation pressure (refrigerant evaporation temperature) of the first evaporator  15 . With respect to the direction of the flow F 1  of the blown air, the first evaporator  15  whose refrigerant evaporation temperature is high is disposed on the upstream side, and the second evaporator  18 ′ whose refrigerant evaporation temperature is low is disposed on the downstream side. Thus, both a difference between the refrigerant evaporation temperature of the first evaporator  15  and the temperature of the blown air, and a difference between the refrigerant evaporation temperature of the second evaporator  18  and the temperature of the blown air can be secured. 
     Thus, both cooling performances of the first and second evaporators  15  and  18  can be exhibited effectively. Therefore, the cooling performance of the common space to be cooled can be improved effectively in the combination of the first and second evaporators  15  and  18 . Furthermore, the effect of pressurization by the diffuser portion  14   d  in the ejector  14  increases the pressure of suction refrigerant of the compressor  11 , thereby decreasing the driving power of the compressor  11 . 
     In the Mollier diagram shown in  FIG. 1B , the solid line shows the operation state of the refrigerant cycle of the present embodiment, the chain line shows the operation state of a comparative refrigerant cycle in which the refrigerant is decompressed only in iso-enthalpy by an expansion valve. The refrigerant pressure P 1  at the outlet of the thermal expansion valve  13  in the refrigerant cycle of the present embodiment is greatly higher than the refrigerant pressure P 2  at the outlet of the thermal expansion valve of the refrigerant cycle in the comparative example. 
     The refrigerant dryness D 1  at the outlet of the thermal expansion valve  13  in the refrigerant cycle of the present embodiment is smaller than the refrigerant dryness D 2  at the outlet of the thermal expansion valve of the refrigerant cycle in the comparative example. Thus, the refrigerant flowing into the flow amount distributor  16  becomes in a gas-liquid two-phase refrigerant, in the present embodiment. As shown in  FIG. 4 , the gas-liquid two-phase refrigerant is separated within the cylindrical space  16   d  of the flow amount distributor  16  into the liquid refrigerant on the bottom side and the gas refrigerant on the upper side by its weight. 
     Thus, by suitably setting the position and the open area of the second flow outlet  16   c  of the flow amount distributor  16 , the flow amount of the liquid refrigerant flowing into the throttle mechanism  17  can be suitably adjusted, thereby suitably adjusting the dryness of the refrigerant flowing into the throttle mechanism  17 . Because the dryness (inlet dryness) of the refrigerant flowing into the throttle mechanism  17  can be suitably adjusted, the dryness of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  can be also suitably adjusted. 
     For example, as shown in  FIG. 4 , a dimension Ht in the top-bottom direction between the center in the circular cross-section of the flow amount distributor  16  and the position of the second outlet port  16   c  can be made larger, so as to set the position of the second outlet port  16   c  at a lower side. By setting the position of the second outlet port  16   c  at the lower side in the cylindrical wall surface of the flow amount distributor  16 , or/and by setting the open area of the second outlet port  16   c  to be larger, the flow amount of the liquid refrigerant flowing into the throttle mechanism  17  becomes larger, and thereby the dryness of the refrigerant flowing into the throttle mechanism  17  can be made smaller. At the same time, the dryness of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  becomes larger. 
     Conversely, by setting the position of the second outlet port  16   c  at an upper side in the cylindrical wall surface of the flow amount distributor  16 , or/and by setting the open area of the second outlet port  16   c  to be smaller, the flow amount of the liquid refrigerant flowing into the throttle mechanism  17  becomes smaller, and thereby the dryness of the refrigerant flowing into the throttle mechanism  17  can be made larger. At the same time, the dryness of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  becomes smaller. 
     As described above, because the dryness of the refrigerant at the inlet side of the throttle mechanism  17  and the dryness of the refrigerant at the inlet side of the nozzle portion  14   a  are adjusted, the flow amounts of the refrigerant flowing into the throttle mechanism  17  and the nozzle portion  14   a  of the ejector  14  can be stably adjusted, thereby making the pressure increase in the ejector  14  to be stable in accordance with a load variation in the ejector refrigerant cycle device  10 . As a result, the performance (e.g., cooling capacity, COP etc.) of the refrigerant cycle having the ejector  14  can be effectively improved in the refrigeration cycle device  10 . 
     In the present embodiment, the flow amount distributor  16  is adapted as a separation portion for separating the refrigerant flowing in the cylindrical space  16   d  into gas refrigerant and liquid refrigerant, and is also adapted as a refrigerant distribution portion for distributing the gas-liquid refrigerant separated in the cylindrical space  16   d  into the nozzle portion  14   a  and the second evaporator  18 . 
     Next, detail structures of the throttle mechanism  17  will be described based on  FIGS. 5A and 5B .  FIG. 5A  shows specific examples used as the throttle mechanism  17 . As the throttle mechanism  17 , a capillary tube  40 , a taper nozzle  41 , a Laval nozzle  42  or a taper-straight combination nozzle  43  may be used, for example, as shown in  FIG. 5A . 
     The capillary tube  40  has a constant inner diameter, and adjusts the flow amount based on the pipe friction with the refrigerant flow. The taper nozzle  41  and the Laval nozzle  42  are configured to change its inner diameter in accordance with the density variation of the refrigerant. 
     For example, the inner diameter of the taper nozzle  41  is made smaller as toward a refrigerant downstream side. The Laval nozzle  42  has a throat portion  42   a  at which the inner diameter (passage sectional area) of the refrigerant passage becomes smallest so that the refrigerant is accelerated to a supersonic speed. 
     The taper-straight combination nozzle  43  corresponds to a combination nozzle in which the taper nozzle  41  and the capillary tube  40  are combined in line. Specifically, the taper-straight combination nozzle  43  is formed into approximately a funnel shape, to have a taper portion  43   a  in which the inner diameter is reduced as toward downstream of the refrigerant flow, and a straight portion  43   b  extending from the downstream end of the taper portion  43  by a predetermined distance. The straight portion  43   b  has a constant inner diameter that is substantially equal to the inner diameter at the downstream end of the taper portion  43   a.    
       FIG. 5B  shows the relationship between the dryness (inlet dryness) of the refrigerant at the inlet side of the respective examples 40-43 used as the throttle mechanism, and the refrigerant flow amount. E 1  shows the example where the taper nozzle  41  or the Laval nozzle  42  is used as the throttle mechanism  17 , E 2  shows the example where the taper-straight combination nozzle  43  is used as the throttle mechanism  17 , and E 3  shows the example where the capillary tube  40  is used as the throttle mechanism  17 . The refrigerant dryness at the inlet side of the throttle mechanism  17  is changed in accordance with a load variation in the ejector refrigerant cycle device  10 . Therefore, as the throttle mechanism  17 , it is proper to have a small variation in the refrigerant flow amount with respect to the variation of the refrigerant dryness at the inlet side of the throttle mechanism  17 , in the ejector refrigerant cycle device  10  where the load variation is larger. 
     In the example E 3  in which the capillary tube  40  is used as the throttle mechanism  17 , the variation of the refrigerant flow amount relative to the variation of the refrigerant dryness at the inlet side of the throttle mechanism  17  is relatively small as shown in the arrow C 1  of  FIG. 5B , as compared with the examples E 1  and E 2 . Therefore, when the capillary tube  40  is used as the throttle mechanism  17 , the operation of the ejector refrigerant cycle device  10  can be made stable. 
     Generally, when the capillary tube  40  is used as the throttle mechanism  17  as in the example E 3 , a ratio (L/D) of the entire length (L) to the inner diameter (D) in the throttle mechanism  17  becomes relatively large as shown in  FIG. 5A , and thereby it may be difficult to simply reduce the whole size of the integrated evaporator unit  20 . 
     When the taper nozzle  41  or the Laval nozzle  42  is used as the throttle mechanism  17  as in the example of E 1 , the ratio (L/D) of the entire length (L) to the inner diameter (D) in the throttle mechanism  17  becomes relatively small as shown in  FIG. 5A , and thereby it may be easy to simply reduce the whole size of the integrated evaporator unit  20 . In addition, in this case, because the refrigerant can be accelerated to the supersonic speed, the refrigerant distribution performance in the first tank space  29  of the upper lank  18   b  of the second evaporator  18  can be improved. 
     However, when the taper nozzle  41  or the Laval nozzle  42  is used as the throttle mechanism  17 , the variation of the refrigerant flow amount relative to the variation of the refrigerant dryness at the inlet side of the throttle mechanism  17  is relatively large as shown by the arrow C 2  of  FIG. 5B , and thereby it may be difficult to be used for a refrigerant cycle device operated with a large load variation. 
     In contrast, when the taper-straight combination nozzle  43  is used as the throttle mechanism  17 , it is possible to simply reduce the entire size of the integrated evaporator unit  20  and to make the operation of the ejector refrigerant cycle device  10  in stable. That is, when the taper-straight combination nozzle  43  is used as the throttle mechanism  17 , the above problems in the capillary tube  40  and in the taper nozzle  41  or the Laval nozzle  42  can be solved. 
     The taper-straight combination nozzle  43  corresponds to a combination nozzle combining the capillary tube  40  having a constant inner diameter to the downstream tip end of the taper nozzle  41  in line in an extending direction. In this case, as shown by C 3  in  FIG. 5B , the variation in the refrigerant flow amount to the refrigerant dryness at the inlet side of the throttle mechanism  17  is a middle between the example of the capillary tube  40  and the example of the taper nozzle  41 . In addition, when the taper-straight combination nozzle  43  is used as the throttle mechanism  17 , the ratio (L/D) of the entire length (L) to the inner diameter (D) in the throttle mechanism  17  can be made smaller as compared with the example in which the capillary tube  40  is used as the throttle mechanism  17 . 
     In the present embodiment, when the taper-straight combination nozzle  43  is used as the throttle mechanism  17 , it is possible to simply reduce the entire size of the integrated evaporator unit  20  and to make the operation of the ejector refrigerant cycle device  10  in stable. 
     According to the present embodiment, the ejector  14 , the first evaporator  15 , the flow amount distributor  16 , the throttle mechanism  17  and the second evaporator  18  are integrally assembled to form the integrated evaporator unit  20 , as shown in  FIG. 2 , and thereby it is possible for the integrated evaporator unit  20  to have the single refrigerant inlet  24  and the single refrigerant outlet  25 . 
     Thus, when the ejector refrigerant cycle device  10  is mounted to a vehicle, the single refrigerant inlet  24  used for the entire integrated evaporator unit  20  is connected to the thermal expansion valve  13 , and the single refrigerant outlet  25  used for the entire integrated evaporator unit  20  is connected to the refrigerant suction side of the compressor  11 , thereby finishing the pipe connection operation. 
     Furthermore, as shown in  FIGS. 2 and 3 , the ejector  14 , the flow amount distributor  16  and the ejector case  23  are integrated on the upper surface of the upper tanks  15   b ,  18   b , and are elongated entirely in the longitudinal direction, such that the elongated direction corresponds to the longitudinal direction of the upper tanks  15   b ,  18   b . In the example of  FIG. 3 , the flow amount distributor  16  and the ejector case  23  are arranged in line to continuously extend in the longitudinal direction of the ejector  14 . For example, the outer wall surface of the flow amount distributor  16  and the outer wall surface of the ejector case  23  having therein the ejector  14  are configured to form a continuous cylindrical shape extending in the longitudinal direction of the ejector  14  on the upper tanks  15   b ,  18   b . Furthermore, the throttle mechanism  17  is connected to the second outlet port  16   c  provided at the cylindrical wall surface of the flow amount distributor  16 , and is extended into the upper tank  18   b  of the second evaporator  18 , as shown in  FIGS. 3 and 4 . As a result, the entire size of the integrated evaporator unit  20  can be made smaller and can be assembled simply in compact. 
     Accordingly, the mounting performance of the ejector refrigerant cycle device  10  having the first and second evaporators  15 ,  18  to a vehicle can be improved, and the number of components in the ejector refrigerant cycle device  10  can be reduced, thereby reducing the product cost. 
     Because the connection passage length for connecting the ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the first and second evaporators  15 ,  18  is made minimum in the integrated evaporator unit  20 , pressure loss in the refrigerant passage can be reduced, and heat exchanging amount of the low-pressure refrigerant in the integrated evaporator unit  20  with its atmosphere can be reduced. Accordingly, the cooling performance of the first and second evaporators  15 ,  18  can be effectively improved. 
     Second Embodiment 
     A second embodiment of the present invention will be described with reference to  FIGS. 6A and 6B . In the above-described first embodiment, the single throttle mechanism  17  is attached to the flow amount distributor  16  at a position of the cylindrical wall surface of the flow amount distributor  16 . That is, the second outlet port  16   c  is located at one position in the cylindrical wall surface of the flow amount distributor  16 . However, in the second embodiment, a plurality of the throttle mechanisms  17  are attached to the cylindrical wall surface of the flow amount distributor  16 , as shown in  FIGS. 6A and 6B . 
     As shown in  FIGS. 6A and 6B , the plural throttle mechanisms  17  are arranged in the axial direction (e.g., the left-right direction in  FIG. 6A ) of the cylindrical wall surface of the flow amount distributor  16 . Specifically, the plural throttle mechanisms  17  are arranged in the arrangement direction of the plural tubes  21 , to correspond to the positions of the plural tubes  21  connected to the first tank space  29  of the upper tank  18   b  of the second evaporator  18  in the arrangement direction of the plural tubes  21 . Therefore, the distribution performance of the liquid refrigerant into the plural tubes  21  can be improved. 
     For example, the second outlet ports  16   c  are provided at plural positions of the cylindrical wall surface of the flow amount distributor  16  to be arranged in the axial direction of the flow amount distributor  16 , and are connected, respectively, to the plural throttle mechanisms  17 . 
     By suitably changing the open position of the throttle mechanisms  17  opened into the flow amount distributor  16  in the top-bottom direction, or/and by suitably changing the inlet open areas of the throttle mechanisms  17 , the flow amount Gn of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  and the flow amount Ge of the refrigerant flowing into the refrigerant suction port  14   b  of the ejector  14  via the second evaporator  18  can be suitably changed. In the second embodiment, the other parts of the integrated evaporator unit  20  for the ejector refrigerant cycle device  10  can be made similar to those of the above-described first embodiment. 
     Third Embodiment 
     A third embodiment of the present invention will be described with reference to  FIGS. 7A and 7B . In the above-described second embodiment, the flow amount distributor  16  is formed into a simple cylindrical shape substantially having a constant outer diameter. However, in the third embodiment, as shown in  FIGS. 7A and 7B , a helical groove portion  16   e  is formed in the inner cylindrical wall surface of the flow amount distributor  16  to be recessed from the inner cylindrical wall surface to radially outside in a helical shape, as shown in  FIG. 7A . Therefore, a helical protrusion portion is formed on the outer cylindrical wall surface at the position corresponding to the helical groove portion  16   e.    
     A plurality of the second outlet ports  16   c  are provided in the helical groove portion  16   e  of the flow amount distributor  16 , and a throttle mechanism  17  is configured by the plural second outlet ports  16   c  by adjusting its number and its open areas. The plural second outlet ports  16   c  are arranged in the helical groove portion  16   e  in line in the axial direction of the flow amount distributor  16 . The axial direction of the flow amount distributor  16  corresponds to the extending direction of the ejector  14 . 
     According to the third embodiment, because the gas-liquid two-phase refrigerant flowing into the inlet port  16   a  of the flow amount distributor  16  flows in the flow amount distributor  16  while being swirled along the helical groove portion  16   e  of the flow amount distributor  16 , liquid film is formed in the groove portion  16   e . Therefore, the refrigerant can be separated into gas refrigerant and liquid refrigerant by using the centrifugal force in the flow amount distributor  16 . 
     The liquid film generated in the groove portion  16   e  flows into the first tank space  29  of the upper tank  18   b  of the second evaporator  18  via the plural second outlet ports  16   c  adapted as the throttle mechanism  17 . Accordingly, distribution performance of the liquid refrigerant from the flow amount distributor  16  into the first tank space  29  of the upper tank  18   b  of the second evaporator  18  can be improved, similarly to the above-described second embodiment. The first tank space  29  is adapted as a refrigerant distribution tank portion in the upper tank  18   b  of the second evaporator  18 . Therefore, distribution performance of the liquid refrigerant to the plural tubes  21  of the heat exchange core  18   a  of the second evaporator  18 , communicating with the first tank space  29  of the upper tank  18   b , can be improved. 
     By suitably changing the number or/and open areas of the second outlet ports  16   c  adapted as the throttle mechanism  17 , the flow amount Gn of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  and the flow amount Ge of the refrigerant flowing into the second evaporator  18  can be suitably changed. In the third embodiment, the other parts of the integrated evaporator unit  20  for the ejector refrigerant cycle device  10  can be made similar to those of the above-described first embodiment. 
     Fourth Embodiment 
     A fourth embodiment of the present invention will be described with reference to  FIGS. 8A and 8B . In the above-described embodiments, the inlet port  16   a  is provided at the longitudinal end portion of the flow amount distributor  16  to open toward the axial direction of the flow amount distributor  16 , for example. Furthermore, in the above-described third embodiment, the helical groove portion  16   e  is provided in the inner cylindrical wall surface of the flow amount distributor  16 , so that the gas-liquid refrigerant flowing therein is separated into the gas refrigerant and the liquid refrigerant while being swirled. However, in the fourth embodiment, the inlet port  16   a  is provided at a position shifted from a center of a circular cross section of the flow amount distributor  16  so as to swirl the gas-liquid refrigerant in the cylindrical space  16   d  of the flow amount distributor  16 . 
     For example, as shown in  FIGS. 8A and 8B , the inlet port  16   a  is provided in the flow amount distributor  16  at a position separated from the center of the circular cross section of the flow amount distributor  16  by a dimension D 1  so that the gas-liquid refrigerant flowing into the inlet port  16   a  is swirled in the flow amount, distributor  16 . 
     In the example of  FIGS. 8A and 8B , the inlet port  16   a  of the flow amount distributor  16  is provided in the cylindrical wall surface of the flow amount distributor  16  at a position close to the longitudinal end, so that the gas-liquid refrigerant flows into the flow amount distributor  16  in a tangential direction of the cylindrical wall surface, thereby swirling the refrigerant flowing into the flow amount distributor  16 . 
     By suitably changing the position of the inlet port  16   a  of the flow amount distributor  16 , the width of a liquid film (liquid film width) in the axial direction of the flow amount distributor  16  and the thickness of the liquid film (liquid film thickness) in the radial direction of the flow amount distributor  16  can be suitably changed, and thereby the flow amount Gn of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  and the flow amount Ge of the refrigerant flowing into the refrigerant suction port  14   b  of the ejector  14  via the second evaporator  18  can be suitably changed. In the fourth embodiment, the other parts of the integrated evaporator unit  20  for the ejector refrigerant cycle device  10  can be made similar to those of the above-described first embodiment. 
     Fifth Embodiment 
     A fifth embodiment of the present invention will be described with reference to  FIGS. 9A and 9B . In the above-described fifth embodiment, the inlet port  16   a  is provided at a position shifted from the center of the circular cross section of the flow amount distributor  16  so as to swirl, the gas-liquid refrigerant in the flow amount distributor  16 . In the fifth embodiment, as shown in  FIGS. 9A and 9B , the shape of the inlet port  16   a  of the flow amount distributor  16  is made non-circularly so that the gas-liquid two-phase refrigerant flowing from the inlet port  16   a  is swirled in the flow amount distributor  16 . In the example shown in  FIGS. 9A and 9B , the inlet port  16   a  is provided in the longitudinal end to open in the axial direction, and the open shape of the inlet port  16   a  is approximately a D-shape. 
     By suitably changing the non-circular shape of the inlet port  16   a  of the flow amount distributor  16 , the liquid film width and the liquid film thickness in the flow amount distributor  16  can be suitably changed, and thereby the flow amount Gn of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  and the flow amount Ge of the refrigerant flowing into the refrigerant suction port  14   b  of the ejector  14  via the second evaporator  18  can be suitably changed. In the fifth embodiment, the other parts of the integrated evaporator unit  20  for the ejector refrigerant cycle device  10  can be made similar to those of the above-described first embodiment. 
     Sixth Embodiment 
     A sixth embodiment of the present invention will be described with reference to  FIG. 10 . In the above-described second embodiment, the plural throttle mechanisms  17  are attached to the flow amount distributor  16  so as to provide both the throttle function and the refrigerant distribution function. However, in the sixth embodiment, as shown in  FIG. 10 , only a single throttle mechanism  17  is provided in the flow amount distributor  16 , so as to provide both the throttle function and the refrigerant distribution function. 
     The single throttle mechanism  17  is formed by a taper nozzle or a capillary tube, and is disposed at a lower portion within the flow amount distributor  16  to extend in parallel with the axial direction of the flow amount distributor  16 . Furthermore, a space portion  44  is provided downstream of the throttle mechanism  17  within the flow amount distributor  16  at the lower portion to extend directly from the downstream end of the throttle mechanism  17  to downstream in the axial direction of the flow amount distributor  16 . Furthermore, plural second outlet ports  16   c  of the flow amount distributor  16  are provided in the cylindrical wall surface of the flow amount distributor  16  at positions facing the space portion  44 . The plural second outlet ports  16   c  of the flow amount distributor  16  are arranged in line in the axial direction (ejector longitudinal direction) of the flow amount distributor  16 . 
     Thus, the liquid refrigerant separated at the bottom side of the flow amount distributor  16  passes through the throttle mechanism  17 , the space portion  44  and the plural second outlet ports  16   c , thereby achieving the throttle function and the refrigerant distribution function in the flow amount distributor  16  provided with the throttle mechanism  17 . 
     By suitably changing the number or/and open areas of the second outlet ports  16   c , the flow amount Gn of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  and the flow amount Ge of the refrigerant flowing into the refrigerant suction port  14   b  of the ejector  14  via the second evaporator  18  can be suitably changed. In the sixth embodiment, the other parts of the integrated evaporator unit  20  for the ejector refrigerant cycle device  10  can be made similar to those of the above-described first embodiment. 
     Seventh Embodiment 
     A seventh embodiment of the present invention will be described with reference to  FIG. 11 . In the seventh embodiment, as shown in  FIG. 11 , a refrigerant storage member  50  is provided in the first tank space  29  of the upper tank  18   b  of the second evaporator  18  so as to improve the distribution performance of the refrigerant distributed into the plural tubes  21 , and a refrigerant storage member  51  is provided in the second tank space  27  of the upper tank  15   b  of the first evaporator  15  so as to improve the distribution performance of the refrigerant distributed into the plural tubes  21 . The second tank space  27  of the upper tank  15   b  of the first evaporator  15  is adapted as a first refrigerant distribution tank portion, and the first tank space  29  of the upper tank  18   b  of the second evaporator  18  is adapted as a second refrigerant distribution tank portion, in the integrated evaporator unit  20 . 
     The refrigerant storage member  50  is located in the first tank space  29  of the upper tank  18   b  of the second evaporator  18 , and is formed into a mountain-fold shape having a mountain top (fold line) extending in the axial direction and two rectangular plates at two sides of the mountain top. The refrigerant storage member  50  is located in the first tank space  29  of the upper tank  18   b  of the second evaporator  18  such that the fold line corresponds to the longitudinal direction of the first tank space  29  of the upper tank  18   b , and is protruded to a side opposite to the tubes  21 . 
     As shown in  FIG. 12B , two lower end portions of the refrigerant storage member  50  is brazed to the inner surface of the upper tank  18   b  defining the first tank space  29 . The refrigerant decompressed in the throttle mechanism  17  flows into the upper space of the refrigerant storage member  50  within the second tank space  29 , and liquid refrigerant  60  is stored at two lower end portions of the refrigerant storage member  50  within the second tank space  29  used as the refrigerant distribution tank portion of the second evaporator  18 . 
     As shown in  FIG. 12A , a plurality of hole portions  50   a  are provided in a top portion of the refrigerant storage member  50 . When the refrigerant  60  stored at the lower end portions of the refrigerant storage member  50  is increased and reaches to the hole portions  50   a , the refrigerant overflows from the hole portions  50   a  of the refrigerant storage member  50  to fall toward the tubes  21 , thereby flowing through the tubes  21 . The plural hole portions  50   a  are arranged in the top portion of the refrigerant storage member  50 , in the tank longitudinal direction. In  FIG. 11 , a virtual line of the bottoms of the hole portions  50   a  is indicated by a chain line. As shown in  FIG. 11 , the holes portions  50   a  are provided in the refrigerant storage member  50  such that the open areas of the hole portions  50   a  becomes smaller as toward the refrigerant inlet portion of the first tank space  29  used as the refrigerant distribution tank portion of the second evaporator  18 . 
     The refrigerant storage member  51  located in the first tank space  27  of the upper tank  15   b , used as the refrigerant distribution tank portion of the first evaporator  15 , has a structure similar to the refrigerant storage member  50  located in the first tank space  29  used as the refrigerant distribution tank portion of the second evaporator  18 . The refrigerant storage member  51  is formed into a mountain-fold shape having a mountain top (fold line) extending in the axial direction and two rectangular plates at two sides of the mountain top. The refrigerant storage member  51  is located in the second tank space  27  of the upper tank  15   b  of the first evaporator  15  such that the fold line corresponds to the longitudinal direction of the second tank space  27  of the upper tank  15   b , and is protruded to a side opposite to the tubes  21 . Furthermore, two lower end portions of the refrigerant storage member  51  is brazed to the inner surface of the upper tank  15   b  defining the second tank space  27  used as the refrigerant distribution tank portion of the first evaporator  15 . 
     The refrigerant from the diffuser portion  14   d  of the ejector  15  flows into the upper space of the refrigerant storage member  51  within the second tank space  27 , and liquid refrigerant is stored at two lower end portions of the refrigerant storage member  51  within the second tank space  27  used as the refrigerant distribution tank portion of the first evaporator  15 . 
     A plurality of hole portions  51   a  are provided in a top portion of the refrigerant storage member  51 . When the refrigerant stored at the lower end portions of the refrigerant storage member  51  is increased and reaches to the hole portions  51   a , the refrigerant overflows from the hole portions  51   a  to fall toward the tubes  21 , thereby flowing through the tubes  21 . The plural hole portions  51   a  are arranged in the top portion of the refrigerant storage member  51 , in the tank longitudinal direction. In  FIG. 11 , a virtual line of the bottoms of the hole portions  51   a  is indicated by a chain line. As shown in  FIG. 11 , the holes portions  51   a  are provided in the refrigerant storage member  51  such that the open areas of the hole portions  51   a  becomes smaller as toward the refrigerant inlet portion of the second tank space  27  used as the refrigerant distribution tank portion of the first evaporator  15 . 
     In the present embodiment, because the refrigerant distribution members  50 ,  51  are provided respectively in the first and second refrigerant distribution tank portions ( 27 ,  29 ) of the first evaporator  15  and the second evaporator  18 , the distribution performance of the refrigerant flowing into the plural tubes  21  is improved, thereby making the temperature distribution to be uniform. 
     In the present embodiment, the refrigerant storage members  50 ,  51  are provided, respectively, in both the tank spaces  27 ,  29  used as the first and second refrigerant distribution tank portions of the first and second evaporators  15 ,  18 . However, any one of the refrigerant storage members  50 ,  51  may be provided in the corresponding one of the tank spaces  27 ,  29  used as the first and second refrigerant distribution tank portions of the first and second evaporators  15 ,  18 . 
       FIGS. 13A to 16B  show modification examples of the refrigerant storage members  50 ,  51 , according to the seventh embodiment.  FIGS. 13A and 13B  show a refrigerant storage member  52  that is a first modification example of the seventh embodiment of the present invention. As shown in  FIGS. 13A and 13B , the refrigerant storage member  52  is disposed in the first tank space  29  adapted as the refrigerant distribution tank portion reversely from the refrigerant storage tank member  50 ,  51  in the top-bottom direction. Therefore, the refrigerant storage member  52  has a valley fold shape having two rectangular plates at two sides of the valley line. In this case, a plurality of hole portions  52   a  are formed in tilt surfaces of the refrigerant storage member  52 . 
     When the refrigerant storage member  52  of the first modification example is used in the refrigerant distribution tank portion of the first or second evaporator  15 ,  18 , the liquid refrigerant stores once in a valley portion of the refrigerant storage member  52 . Then, when the refrigerant stored at the valley portion of the refrigerant storage member  52  is increased and reaches to the hole portions  52   a , the refrigerant overflows from the hole portions  52   a  to fall toward the tubes  21 , thereby flowing through the tubes  21 . Instead of the plural hole portions  52   a , cut portions each of which is cut in a minor direction of the refrigerant storage member  52  may be provided in the refrigerant storage member  52 . 
       FIGS. 14A and 14B  show a refrigerant storage member  53  that is a second modification example of the seventh embodiment of the present invention. As shown in  FIGS. 14A and 14B , the refrigerant storage member  53  is a flat rectangular plate having plural hole portions  53   a  arranged in a major direction of the refrigerant storage member  53 , corresponding to the tank longitudinal direction of the refrigerant distribution tank portion. Each of the plural hole portions  53   a  is located at a center area in the refrigerant storage member  53  in a minor direction of the refrigerant storage member  53 . The minor direction is perpendicular to the major direction in the refrigerant storage member  53 . 
     When the refrigerant storage member  53  of the second modification example of the seventh embodiment is used in the refrigerant distribution tank portion of the first or second evaporator  15 ,  18 , the liquid refrigerant stores once on the upper surface of the refrigerant storage member  53 , and then falls toward the tubes  21 , thereby flowing through the tubes  21 . 
       FIGS. 15A and 15B  show a refrigerant storage member  54  that is a third modification example of the seventh embodiment of the present invention. As shown in  FIGS. 15A and 15B , the refrigerant storage member  54  is a flat rectangular plate having plural hole portions  54   a  arranged in a major direction of the refrigerant storage member  54 , corresponding to the tank longitudinal direction of the refrigerant distribution tank portion. Each of the plural hole portions  54   a  is located at an end portion in the refrigerant storage member  54  in a minor direction of the refrigerant storage member  54 . The minor direction is perpendicular to the major direction in the refrigerant storage member  54 . 
     When the refrigerant storage member  54  of the third modification example of the seventh embodiment is used in the refrigerant distribution tank portion of the first or second evaporator  15 ,  18 , the liquid refrigerant stores once on the upper surface of the refrigerant storage member  54 , and then falls toward the tubes  21 , thereby flowing through the tubes  21 . Instead of the plural hole portions  54   a , cut portions each of which is cut at the end portion of the refrigerant storage member  54  in the minor direction may be formed. 
       FIGS. 16A and 16B  show a refrigerant storage member  55  that is a fourth modification example of the seventh embodiment of the present invention. As shown in  FIGS. 16A and 16B , the refrigerant storage member  55  is a flat rectangular plate having plural hole portions  55   a  arranged in two lines in a major direction of the refrigerant storage member  55 , corresponding to the tank longitudinal direction of the refrigerant distribution tank portion. The two lines of the plural hole portions  55   a  are arranged at two end portions in the refrigerant storage member  55  in a minor direction of the refrigerant storage member  55 . The minor direction is perpendicular to the major direction in the refrigerant storage member  55 . 
     When the refrigerant storage member  55  of the fourth modification example of the seventh embodiment is used in the refrigerant distribution tank portion of the first or second evaporator  15 ,  18 , the liquid refrigerant stores once on the upper surface of the refrigerant storage member  55 , and then falls toward the tubes  21 , thereby flowing through the tubes  21 . Instead of the plural hole portions  55   a , cut portions each of which is cut at the end portions of the refrigerant storage member  55  in the minor direction may be formed. 
     In the seventh embodiment and modifications thereof, the other parts of the integrated evaporator unit  20  may be similar to those of the above-described first embodiment. 
     Eighth Embodiment 
     An eighth embodiment and modification examples of the present invention will be described with reference to  FIGS. 17A to 19 . In the above-described first embodiment, the throttle mechanism  17  is provided outside of the flow amount distributor  16 . However, in the eighth embodiment and modification examples of the eighth embodiment, the throttle mechanism  17  is provided inside the flow amount distributor  16 . 
     As shown in  FIGS. 17A and 17B , the flow amount distributor  16  is provided with a swirl generating portion  70  configured to generate a swirl movement to the refrigerant flowing from the inlet port  16   a , and a body portion  71  defining therein the cylindrical space  16   d  in which the refrigerant with the generated swirl movement flows. 
     The body portion  71  is adapted as a gas-liquid separation portion for separating the refrigerant into gas refrigerant and the liquid refrigerant, as well as is also adapted as a refrigerant distribution portion for distributing the separated refrigerant to the nozzle portion  14   a  and the second evaporator  18 . The body portion  71  is a cylinder having approximately constant diameter, and is provided coaxially with the ejector  14 , as shown in  FIG. 17B   
     In the example of  FIGS. 17A and 17B , the swirl generating portion  70  is a cap member configured to cover one end portion of the cylindrical body portion  71 . Thus, the swirl generating portion  70  can be formed separately from the cylindrical body portion  71 .  FIG. 17B  shows a disassemble state of the cylindrical body portion  71  and the swirl generating portion  70  that is adapted as the cap member of the cylindrical body portion  71 . 
     As shown in  FIG. 18 , the cylindrical body portion  71  is configured by a three-layer structure, in which an inner cylinder  711 , a middle cylinder  712  and an outer cylinder  713  are overlapped with each other in the radial direction. The inner cylinder  711  is molded integrally with the nozzle portion  14   a  of the ejector  14 , and the outer cylinder  13  is molded integrally with a body member  14   e  of the ejector  14 . 
     As shown in  FIG. 17B , the body portion  14   e  of the ejector  14  is a member for forming the mixing portion  14   c  and the diffuser portion  14   d  of the ejector  14 . A nozzle forming member  14   f  is accommodated in the body member  14   e , so as to form the nozzle portion  14   a  of the ejector  14 . 
     As shown in  FIG. 18 , the throttle mechanism  17  is formed into a helical capillary tube between the inner cylinder  711  and the middle cylinder  712 . Specifically, a helical groove is formed to be recessed from the inner wall surface of the middle cylinder  712 , thereby form a helical capillary passage  72  between the inner cylinder  711  and the middle cylinder  712 . The helical capillary passage  72  is adapted as a capillary tube for decompressing the refrigerant, and the throttle mechanism  17  is configured by using the helical capillary passage  72 . 
     An inlet hole  711   a  communicating with the helical capillary passage  72  is provided in the inner cylinder  711 , and is used as a capillary inlet port from which the refrigerant is introduced into the helical capillary passage  72 . An outlet hole  713   a  communicating with the helical capillary passage  72  is proved in the outer cylinder  713 , and is used as a capillary outlet port from which the refrigerant having passed through the helical capillary passage  72  flows out. In this example of  FIG. 18 , the hole  713   a  is also adapted as the second outlet port  16   c  of the flow amount distributor  16 , so that the refrigerant flowing out of the hole  713   a  flows into the upper tank  18   b  of the second evaporator  18 . 
     The refrigerant flowing from the inlet port  16   a  of the flow amount distributor  16  flows in the swirl generating portion  70  so that a swirl movement will be generated in the refrigerant, and then flows in the cylindrical space  16   d  of the body portion  71  while being swirled. The refrigerant flowing in the cylindrical space  16   d  of the body portion  71  is separated into gas refrigerant on the radial center side of the cylindrical space  16   d , and liquid refrigerant on the radial outer side of the cylindrical space  16   d , by using the centrifugal force of the swirl flow. 
     The separated liquid refrigerant flows while being swirled along the inner wall surface of the cylindrical body portion  71 , and flows into the capillary passage  72  from the capillary inlet hole  711   a . The refrigerant having been decompressed in the capillary passage  72  flows into a refrigerant distribution tank portion of the upper tank  18   b  of the second evaporator  18  from the capillary outlet hole  713   a.    
     According to the present embodiment, because the throttle mechanism  17  is configured by the helical capillary passage  72 , it is possible to reduce the variation in the refrigerant flow amount with respect to the variation in the refrigerant dryness at the inlet side of the throttle mechanism  17 , as in the arrow C 1  of  FIG. 5B . 
     In contrast, the throttle mechanism  17  is formed into the capillary tube, and thereby the ratio (L/D) of the entire length (L) of the throttle mechanism  17  to the inner diameter (D) becomes larger. However, in the present embodiment, because the throttle mechanism  17  is configured by the helical capillary passage  72  provided in the flow amount distributor  16 , the entire size of the integrated evaporator unit  20  can be made small. 
       FIG. 19  shows a modification example of the eighth embodiment of the present invention. In the example of  FIG. 19 , a helical capillary passage  72  is provided on the outer wall surface of the inner cylinder  711 , thereby forming the throttle mechanism  17 . 
     In the eighth embodiment and the modification example thereof, the other parts of the integrated evaporator unit  20  may be similar to those of the above-described first embodiment. 
     Ninth Embodiment 
     A ninth embodiment of the present invention will be described with reference to  FIGS. 20A and 20B . In the above-described eighth embodiment, the cylindrical body portion  71  of the flow amount distributor  16  is configured by the three-layer structure. However, in the ninth embodiment, the cylindrical body portion  71  is configured by a double-layer structure in which an inner cylinder  711  and an outer cylinder  713  are overlapped with each other in the radial direction, as shown in  FIGS. 20A and 20B . 
       FIG. 20A  shows an example of the cylindrical body portion  71 , in which the inner cylinder  711  is molded separately from the nozzle forming member  14   f  of the ejector  14 , and the nozzle forming member  14   f  is fitted into the inner cylinder  711 . In the cylindrical body portion  71  of  FIG. 20A , the outer cylinder  713  is molded integrally with the body member  14   e  of the ejector  14 . A helical groove is formed on the outer wall surface of the inner cylinder  711  to be recessed from the outer wall surface of the inner cylinder  711 , so as to form a helical capillary passage  72  between the inner cylinder  711  and the outer cylinder  713 . 
       FIG. 20B  shows another example of the cylindrical body portion  71 , in which the nozzle forming member  14   f  has an outer diameter approximately equal to the inner diameter of the outer cylinder  713 , and the nozzle forming member  14   f  is fitted into the outer cylinder  713 . In the example of  FIG. 20B , the inner cylinder  711  may be molded integrally with the nozzle forming member  14   f , or may be molded separately from the nozzle forming member  14   f.    
     In the ninth embodiment, because the throttle mechanism  17  configured by the helical capillary passage  72  is provided in the flow amount distributor  16 , the same effects described in the eighth embodiment can be obtained. In addition, because the cylindrical body portion  71  is configured by the double-layer structure, and the helical capillary passage  72  is provided between the inner cylinder  711  and the outer cylinder  713 , the helical capillary passage  72  can be easily formed in the cylindrical body portion  71 . A helical groove may be provided in the inner wall surface of the outer cylinder  713  so as to form the helical capillary passage  72  between the inner cylinder  711  and the outer cylinder  713 . 
     When the inner cylinder  711  is molded separately from the nozzle forming member  14   f , the molding length of the nozzle forming member  14   f  can be made shorter, thereby easily accurately forming the nozzle forming member  14   f.    
     In the ninth embodiment, the other parts of the integrated evaporator unit  20  may be similar to those of the above-described eighth embodiment. 
     Tenth Embodiment 
     A tenth embodiment of the present invention will be described with, reference to  FIG. 21 . In the above-described ninth embodiment, the single helical capillary passage  72  is provided between the inner cylinder  711  and the outer cylinder  713 . In the tenth embodiment, as shown in  FIG. 21 , plural capillary passages  72  are formed between the inner cylinder  711  and the outer cylinder  713 . 
     In the example of  FIG. 21 , inlet sides of the plural capillary passages  72  are connected to a circular groove  711   b  provided along an entire circular periphery of the inner cylinder  711 , and outlet sides of the plural capillary passages  72  are connected to a circular groove  711   c  provided along an entire circular periphery of the inner cylinder  711 . A plurality of inlet holes  711   a  are provided in the circular groove  711   b  of the inner cylinder  711  to be arranged in the circumferential direction of the inner cylinder  711 . 
     In the present embodiment, the plural capillary passages  72  are provided respectively separately, and are extended approximately in parallel. Thus, it is possible to reduce the length of each of the capillary passages  72 , thereby shorten the entire length of the body portion  71  of the flow amount distributor  16 . Furthermore, because the length of each capillary passage  72  can be made short, the capillary passage  72  can be formed approximately straightly based on the numbers of the capillary passages  72  and the length of each capillary passage  72 , without being limited to the helical shape. 
     Furthermore, even when one of the capillary passages  72  is blocked by a foreign material or the like to deteriorate the refrigerant flow, because the refrigerant can flows through the other capillary passages  72 , the decompression of the refrigerant can be substantially obtained without being affected by the blocked capillary passage  72 . 
     In the present embodiment, the outlet sides of the capillary passages  72  are connected to the single circular groove  711   c  extending along the entire periphery of the inner cylinder  711 , thereby easily fitting the position with the outlet hole  713   a  provided in the outer cylinder  713 . 
     In the present embodiment, by suitably setting the number of the capillary passages  72 , the ratio (Ge/Gn) of the flow amount Ge of the refrigerant flowing into the refrigerant suction port  14   b  of the ejector  14  via the second evaporator  18  to the flow amount Gn of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  can be suitably controlled. 
     Because the plural inlet holes  711   a  are provided in the circular groove  711   b  at plural positions in the circumferential direction, the refrigerant from the swirl generating portion  70  can be introduced into the capillary passages  72  in uniform. 
     Thus, a liquid film of the liquid refrigerant flowing along the outer wall surface of the inner cylinder  711  can be made thinner entirely, thereby preventing a meandering flow of gas refrigerant due to the different of the thickness of the liquid film, when the liquid refrigerant flows through the capillary passages  72 . Therefore, the ratio (Ge/Gn) of the flow amount Ge of the refrigerant flowing into the refrigerant suction port  14   b  of the ejector  14  to the flow amount Gn of the refrigerant flowing into the nozzle portion  14   a  of the ejector  14  can be increased. 
     Eleventh Embodiment 
     An eleventh embodiment of the present invention will be described with reference to  FIGS. 22A and 22B . In the eleventh embodiment, as shown in  FIG. 22B , the flow amount distributor  16  is formed integrally with the ejector  14 . 
     Specifically, a cylindrical outer cell of the flow amount distributor  16  is formed by a body member  14   e  of the ejector  14 , and a pipe portion  14   g  is formed integrally with a nozzle forming member  14   f  at the inlet side of the nozzle forming member  14   f . An inlet port  16   a  and an outlet port  16   c  of the flow amount distributor  16  are provided in a cylindrical wall surface of the body member  14   e . The outlet port  16   c  is formed in an orifice shape or a nozzle shape so as to be adapted as the throttle mechanism  17 . 
     The gas-liquid refrigerant flowing from the inlet port  16   a  is separated into gas refrigerant and liquid refrigerant in the flow amount distributor  16  by using a centrifugal force of the swirl flow. Similarly to the fourth embodiment, a swirl generating portion is provided at an inlet side of the flow amount distributor  16  so that a swirl movement is applied to the refrigerant flowing in the cylindrical body portion  14   e . As a result, a gas-rich refrigerant flows in the cylindrical space  16   d  of the flow amount distributor  16  at a radial center side of the body member  14   e , and is introduced into the nozzle portion  14   a  of the nozzle forming member  14   f  via the pipe portion  14   g  of the nozzle forming member  14   f.    
     On the other hand, a liquid-rich refrigerant flows in the cylindrical space  16   d  of the flow amount distributor  16  while being swirled along the inner peripheral surface of the body member  14   e , and is introduced into the refrigerant distribution tank portion of the upper tank  18   b  of the second evaporator  18  from the outlet port  16   c  provided in the cylindrical wall surface of the body member  14   e.    
     Thus, the pipe portion  14   g  can be adapted as a partition wall for partitioning the gas-rich refrigerant and the liquid-rich refrigerant; thereby easily separating the gas-rich refrigerant and the liquid-rich refrigerant from each other. 
     In the present embodiment, the pipe portion  14   g  is provided at the inlet side portion of the nozzle forming member  14   f  so that the flow amount distributor  16  is formed integrally with the ejector  14 . Therefore, the integrated structure between the ejector  14  and the flow amount distributor  16  can be easily formed. Further the throttle mechanism  17  is formed integrally with the ejector  14  by simply forming the outlet port  16   c  in the cylindrical wall surface of the body member  14   e.    
     In the eleventh embodiment, the other parts of an integrated evaporator unit  20  may be similar to those of the above-described first embodiment. 
     Twelfth Embodiment 
     A twelfth embodiment of the present invention will be described with reference to  FIGS. 23A and 24D . In the above-described eleventh embodiment, the integrated member of the flow amount distributor  16  and the ejector  14  is configured such that the refrigerant flows while being swirled in the body member  14   e  of the ejector  14 . However; in the twelfth embodiment, as shown in  FIGS. 23A and 23B , the flow amount distributor  16  is configured by the nozzle forming member  14   f  such that the refrigerant flows in the flow amount distributor  16  while being swirled in the nozzle forming member  14   f  of the ejector  14 . 
     As shown in  FIGS. 23A and 23B , an inlet side portion of the nozzle forming member  14   f  is made to protrude from the body member  14   e , and an inlet port  16   a  and an outlet port  16   c  are provided in a cylindrical wall surface of the protruded nozzle forming member  14   f.    
       FIG. 23A  shows an example in which the outlet port  16   c  adapted as the throttle mechanism  17  is an orifice, and  FIG. 23B  shows an example in which the outlet port  16   c  adapted as the throttle mechanism  17  is formed into a nozzle shape. 
     The gas-liquid refrigerant flowing from the inlet port  16   a  is separated into gas refrigerant and liquid refrigerant in the flow amount distributor  16  by using a centrifugal force of the swirl flow. As a result, a gas-rich refrigerant flows in the nozzle forming member  14   f  in a portion used as the flow amount distributor  16  at a radial center side of the nozzle forming member  14   f , is introduced into the nozzle portion  14   a  of the nozzle forming member  14   f , and is jetted into the mixing portion  14   c  of the ejector  14  from the refrigerant jet port of the nozzle portion  14   a.    
     On the other hand, a liquid-rich refrigerant flows in the nozzle forming member  14   f  in a portion adapted as the flow amount distributor  16  while being swirled along the inner peripheral surface of the nozzle forming member  14   f , and is introduced into the refrigerant distribution tank portion of the upper tank  18   b  of the second evaporator  18  via the outlet port  16   c  provided in the cylindrical wall surface of the protruded nozzle forming member  14   f.    
     According to the present embodiment, because the flow amount distributor  16  is configured in the nozzle forming member  14   f  without using a pipe member, the integrated structure of the flow amount distributor  16  and the ejector  14  can be easily formed. 
       FIGS. 24A to 24D  show special examples of the outlet port  16   c , adapted as a throttle different from the throttle mechanism  17 .  FIG. 24A  shows an example in which a single straight passage is connected to the flow amount distributor  16  to have the outlet port  16   c ,  FIG. 24B  shows an example in which a taper-straight nozzle combination member is connected to the flow amount distributor  16  to have the outlet port  16   c ,  FIG. 24C  shows an example in which an orifice-straight passage combination member is connected to the flow amount distributor  16  to have the outlet port  16   c , and  FIG. 24D  shows an example in which a capillary tube is connected to the flow amount distributor  16  to have the outlet port  16   c.    
     In the examples of  FIGS. 24A to 24D , the outlet port  16   c  is open radially outside of the nozzle forming member  14   f , while the inlet port  16   a  is open in the axial direction. However, the inlet port  16   a  may be open in the nozzle forming member  14   f  in a radial direction, similarly to the examples of  FIGS. 23A and 23B . 
     Other Embodiments 
     Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. 
     (1) At least in the above-described first embodiment, the ejector  14  is accommodated in the ejector case  23 , and the ejector case  23  having therein the ejector  14  is attached to the outer surface of the upper tanks  15   b ,  18   b  of the first and second evaporators  15 ,  18 . However, the ejector case  23  may be omitted, and the ejector  14  can be directly attached to the outer surface of the upper tank  15   b ,  18   b  without using the ejector case  23 . 
     (2) In the above-described embodiments, the ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the ejector case  23  are assembled to the top surface of the upper tanks  15   b ,  18   b  of the first and second evaporators  15 ,  18 . However, the ejector  14 , the flow amount distributor  16 , the throttle mechanism  17  and the ejector case  23  may be assembled to a surface of the first and second evaporators  15 ,  18 , except for the top surface of the upper tanks  15   b ,  18   b , such as a side surface of the first and second evaporators  15 ,  18 . 
     (3) Although in the above-mentioned respective embodiments, the vapor-compression subcritical refrigerant cycle has been described in which the refrigerant is a flon-based one, an HC-based one, or the like, whose high pressure does not exceed the critical pressure, the invention may be applied to a vapor-compression supercritical refrigerant cycle which employs the refrigerant, such as carbon dioxide (CO 2 ), whose high pressure exceeds the critical pressure. 
     In the supercritical refrigerant cycle, only the refrigerant discharged by the compressor  11  dissipates heat in the supercritical state at the radiator  12 , and hence is not condensed. 
     (4) Although in the above-mentioned embodiments, the exemplary ejector  14  is a fixed ejector having the nozzle portion  14   a  with the certain path area, the ejector  14  for use may be a variable ejector having a variable nozzle portion whose path area is adjustable. 
     For example, the variable nozzle portion may be a mechanism which is configured to adjust the path area by controlling the position of a needle inserted into a passage of the variable nozzle portion using the electric actuator. 
     (5) Although in the first embodiment and the like, the invention is applied to the refrigeration cycle device adapted for cooling the interior of the vehicle and for the freezer and refrigerator, both the first evaporator  15  whose refrigeration evaporation temperature is high and the second evaporator  18  whose refrigeration evaporation temperature is low may be used for cooling different areas inside the compartment of the vehicle (for example, an area on a front seat side inside the compartment of the vehicle, and an area on a back seat side therein). 
     Alternatively or additionally, both the first evaporator  15  whose refrigeration evaporation temperature is high and the second evaporator  18  whose refrigeration evaporation temperature is low may be used for cooling the freezer and refrigerator. That is, a refrigeration chamber of the freezer and refrigerator may be cooled by the first evaporator  15  whose refrigeration evaporation temperature is high, while a freezing chamber of the freezer and refrigerator may be cooled by the second evaporator  18  whose refrigeration evaporation temperature is low. 
     (6) Although in the first embodiment and the like, the thermal expansion valve  13  and the temperature sensing part  13   a  are separately provided from the integrated evaporator unit  20  for the ejector refrigerant cycle device, the thermal expansion valve  13  and the temperature sensing part  13   a  may be integrally incorporated in the integrated evaporator unit  20  for the ejector refrigerant cycle device  10 . 
     (7) It is apparent that although in the above-mentioned respective embodiments, the refrigeration cycle device for the vehicle has been described, the invention can be applied not only to the vehicle, but also to a fixed refrigeration cycle or the like in the same way. 
     (8) In the above-described embodiments, any two or more embodiments or modification examples thereof may be suitably combined if there are no have any contradiction in the combination. 
     For example, when the flow amount distributor  16  is adapted as both of a gas-liquid separation portion for separating the refrigerant flowing therein into gas refrigerant and liquid refrigerant and a refrigerant distribution portion for distributing the separated refrigerant into the nozzle portion  41   a  and the second evaporator  18 , and when the flow amount distributor  16  and the ejector  14  are arranged in line in the longitudinal direction of the ejector  14 , the other configuration in the evaporator unit  20  may be suitably changed without being limited to each example in the above-described embodiments. 
     Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims.