Abstract:
A refrigerant circuit for a vehicle heating, ventilation, and air conditioning system is disclosed, wherein the refrigerant circuit includes a combined component including an internal heat exchanger and an accumulator, and wherein a cost and difficulty of manufacture and assembly thereof are minimized, and an efficiency thereof is maximized.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of German Patent Application No. 102006038728.7 REFRIGERANT CIRCUIT SYSTEM filed on Aug. 11, 2006, hereby incorporated herein by reference in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The invention generally relates to a refrigerant circuit system and more particularly, to a refrigerant circuit system for a vehicle heating, ventilation, and air conditioning system (HVAC). 
       BACKGROUND OF THE INVENTION 
       [0003]    Refrigerant circuit systems that employ CO 2 , as a refrigerant are particularly used in motor vehicle HVACs. Refrigerant circuit systems are provided with a compressor for compressing the gas and a gas cooler for cooling the gas discharged by the compressor. After the gas has been cooled down in the gas cooler, it flows into an internal heat exchanger. The internal heat exchanger functions to transfer heat within the system for supercooling from the high-pressure side to the low-pressure side, which is thereby heated. The high-pressure exit of the internal heat exchanger directs the refrigerant to an expansion member which reduces the pressure of the refrigerant. The expanding refrigerant is passed through an evaporator, to the outside of which air is directed which is thus cooled to serve for vehicle air conditioning. Coming from the evaporator the refrigerant is fed to the accumulator where the refrigerant is intermediately stored before a quantity of refrigerant required, dependent on the operational state, again reaches the compressor. Another function of the accumulator is to provide a refrigerant reserve stock to compensate for leakage losses which occur in the maintenance interval. 
         [0004]    In HVACs, systems are increasingly used that contain two evaporators switched in parallel. In addition to the two evaporators switched in parallel, the refrigerant circuit of such a prior art HVAC includes a compressor, a gas cooler, an internal heat exchanger, and two expansion members arranged upstream of the two parallel evaporators. From a compressor, the refrigerant at high pressure reaches a gas cooler where the refrigerant is cooled by an environmental air current. Then the refrigerant flows over the high-pressure entrance into the internal heat exchanger and, after having passed the internal heat exchanger, over a high-pressure exit to a manifold connection. The manifold connection is located on the refrigerant line, the manifold, being established as a three-way screwed connector, dividing the refrigerant line into two branches which run parallel to each other. Downstream in each of the branches, first, an expansion member is disposed which the refrigerant reaches after having passed the manifold. In each of the two branches of the refrigerant line, the expanding refrigerant is then directed to an evaporator, to the outside of which air is directed, which on its part is cooled thereby to serve for vehicle air conditioning. Both branches then lead from the respective evaporator over two different entrances into a collector (accumulator), where the refrigerant is intermediately stored before over the low-pressure entrance it can flow into the internal heat exchanger and from there over the low-pressure exit reach the compressor again. 
         [0005]    In such two-evaporator systems, additional manifold connections are required. Typically, these manifold connections are located on a refrigerant line thus requiring an additional screwing process each at both the high-pressure and low-pressure sides, as there is a second evaporator branch which in addition to the second evaporator includes a second expansion member upstream to the second evaporator. Thus, the increased number of screwing points and growing interconnection of the lines not only results in increased effort during manufacture, but also raised material costs. 
         [0006]    Accordingly, it would be desirable to produce a refrigerant circuit system for use in vehicle HVACs, wherein a cost and difficulty of manufacture and assembly thereof are minimized, and an efficiency thereof is maximized. 
       SUMMARY OF THE INVENTION 
       [0007]    Harmonious with the present invention, a refrigerant circuit system for use in vehicle HVACs, wherein a cost and difficulty of manufacture and assembly thereof are minimized, and an efficiency thereof is maximized, has surprisingly been discovered. 
         [0008]    In one embodiment, a refrigerant circuit system comprises a compressor; a gas cooler in fluid communication with the compressor; a combined component in fluid communication with the compressor and the gas cooler, the combined component including an internal heat exchanger and an accumulator, the internal heat exchanger including a high-pressure entrance and a pair of high pressure exits, the accumulator including a pair of low pressure entrances and a low pressure exit; and a pair of branches including an evaporator and an expansion member, wherein one of the branches is in fluid communication with one of the high pressure exits of the internal heat exchanger and one of the low pressure entrances of the accumulator and the other of the branches is in fluid communication with the other of the high pressure exits of the internal heat exchanger and the other of the low pressure entrances of the accumulator. 
         [0009]    In another embodiment, a refrigerant circuit system comprises a compressor; a gas cooler in fluid communication with the compressor; a combined component in fluid communication with the compressor and the gas cooler, the combined component including an internal heat exchanger and an accumulator, the internal heat exchanger including a high-pressure entrance and a pair of high pressure exits, the accumulator including a pair of low pressure entrances and a low pressure exit; a refrigerant line for interconnecting the gas cooler to the compressor, the gas cooler to the combined component, and the combined component to the compressor; and a pair of branches including an evaporator and an expansion member, wherein one of the branches is in fluid communication with one of the high pressure exits of the internal heat exchanger and one of the low pressure entrances of the accumulator and the other of the branches is in fluid communication with the other of the high pressure exits of the internal heat exchanger and the other of the low pressure entrances of the accumulator, and wherein the evaporators are disposed downstream of the expansion members, and the pair of branches form a parallel circuit from the combined component. 
         [0010]    In another embodiment, a refrigerant circuit system comprises a compressor; a gas cooler in fluid communication with the compressor; a combined component in fluid communication with the compressor and the gas cooler, the combined component including an internal heat exchanger and an accumulator, the internal heat exchanger including a high-pressure entrance and a pair of high pressure exits, the accumulator including a pair of low pressure entrances and a low pressure exit; a refrigerant line for interconnecting the gas cooler to the compressor, the gas cooler to the combined component, and the combined component to the compressor; a pair of branches including an evaporator and an expansion member, wherein one of the branches is in fluid communication with one of the high pressure exits of the internal heat exchanger and one of the low pressure entrances of the accumulator and the other of the branches is in fluid communication with the other of the high pressure exits of the internal heat exchanger and the other of the low pressure entrances of the accumulator, and wherein the evaporators are disposed downstream of the expansion members, and the pair of branches form a parallel circuit from the combined component; and a manifold disposed on the combined component, wherein the manifold facilitates communication between the combined component and the pair of branches, the manifold including a first double connection element that facilitates communication between the manifold and the expansion member and manifold and the evaporator in one of the branches, and a second double connection element that facilitates communication between the manifold and the expansion member and the manifold and the evaporator in the other one of the branches. 
         [0011]    The problem is solved by a refrigerant circuit system, particularly for a motor vehicle HVAC with CO 2  as refrigerant, the system provided with two evaporators switched in parallel as well as a combined component which includes an internal heat exchanger and an accumulator so that the functionalities of an internal heat exchanger and an accumulator are combined within one single component. The invention is characterized by that three-way screwing points, which in prior art are placed on the refrigerant lines, are shifted to the combined component comprising an accumulator and an internal heat exchanger. 
         [0012]    In the refrigerant circuit system according to this invention, the refrigerant is directed along the refrigerant line over a compressor and a gas cooler into the high-pressure entrance of an internal heat exchanger which has to transfer within the system heat for supercooling from the high-pressure side to the low-pressure side which on its part is thereby heated. Downstream of the high-pressure exit of the internal heat exchanger, the refrigerant line divides into two different branches switched in parallel to each other, each provided with an expansion member and an evaporator downstream of each expansion member. According to the invention, the internal heat exchanger together with the accumulator forms one component in the form of a combined component. In this combined component, the refrigerant, which is passed through the internal heat exchanger on the high-pressure side thereof, comes into thermal contact with the refrigerant taken from the accumulator, where it has been intermediately stored on the low-pressure side thereof. According to the invention, the two parallel switched branches of the refrigerant line, in each of which an expansion member and an evaporator located downstream of the expansion member are disposed, start at one of the high-pressure exits of the combined component comprising an internal heat exchanger and an accumulator to end into a low-pressure entrance of the combined component. The low-pressure entrances of the combined component, comprising an internal heat exchanger and an accumulator, lead into the low-pressure accumulator region of the combined component, the region serving to intermediately store the refrigerant at low pressure. When the intermediately stored refrigerant is taken, the refrigerant flows over the low-pressure exit of the combined component comprising an internal heat exchanger and an accumulator along the refrigerant line again to the compressor so that the refrigerant circuit system is closed. 
         [0013]    The principle of the invention is that the connection points to the two evaporators are shifted from the refrigerant lines (prior art) to the combined component comprising an accumulator and an internal heat exchanger. In order to achieve that, a manifold is disposed on the combined component comprising an internal heat exchanger and an accumulator in an embodiment of the invention. The manifold contains the screwing points for the connection of the combined component to the two branches switched parallel to each other. 
         [0014]    In one embodiment, the manifold is equipped with double connection elements, which allows a minimization of the number of screwing points and simplifies the interconnection of the lines, resulting in a more clearly arranged line design. 
         [0015]    The double connection elements ensure to make the connections of the combined component to one, in each case, of the parallel switched branches of the refrigerant line with expansion member and evaporator on both the high-pressure side and the low-pressure side. 
         [0016]    A first double connection element includes two connections for the refrigerant line for the first branch of the parallel switched branches of the refrigerant line. One connection is at the first high-pressure exit from the combined component provided for that portion of the refrigerant line that leads from the first high-pressure exit to the first expansion member. A second connection, provided at the first low-pressure entrance, connects the first evaporator to the first low-pressure entrance of the combined component by means of the refrigerant line. 
         [0017]    A second double connection element includes two connections for the refrigerant line in the second branch. This double connection element can be placed in parallel opposite to or in parallel above, or below, respectively, of the first double connection element. However, an arrangement is also possible where the double connection elements are placed in parallel at different levels and on opposite sides. In all cases, a first connection placed at the second high-pressure exit of the combined component is provided for the portion of the refrigerant line that leads from the second high-pressure exit to the second expansion member. A second connection placed at the second low-pressure entrance of the combined component serves to attach the portion of the refrigerant line that leads from the second evaporator to the second low-pressure entrance. 
         [0018]    Typically, either one or two screws are required for fastening a double connection element which save time-intensive screwing operations. 
         [0019]    Compared to prior art, the solution according to this invention facilitates a cost-effective and time-effective manufacture process. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    The above and other objects and advantages of the invention will become readily apparent to those skilled in the art from reading the following descriptions of several embodiments of the invention when considered in the light of the accompanying drawings in which: 
           [0021]      FIG. 1  is a block diagram of an HVAC system with two parallel switched evaporators according to the prior art; 
           [0022]      FIG. 2  is a block diagram of an HVAC system with a combined component including an accumulator and an internal heat exchanger and two double connection blocks according to an embodiment of the invention; 
           [0023]      FIG. 3   a  is a perspective view of a branch portion of the refrigerant line illustrated in  FIG. 1  with two three-way screwing points located on the refrigerant line; 
           [0024]      FIG. 3   b  is a perspective view of a branch portion of the refrigerant line illustrated in  FIG. 1  with one screwing point located on the refrigerant line; 
           [0025]      FIG. 4   a  is a perspective view of the combined component comprising an accumulator and an internal heat exchanger illustrated in  FIG. 2  including a manifold with double connection elements and screwing points arranged opposite in parallel; 
           [0026]      FIG. 4   b  is a perspective view of the combined component of accumulator and internal heat exchanger illustrated in  FIG. 2  including a manifold with double connection elements and screwing points arranged one above another; 
           [0027]      FIGS. 5   a - 5   f  are detailed views of the manifold with connections placed opposite to each other illustrated in  FIG. 4   a;  and 
           [0028]      FIGS. 6   a - 6   f  are detailed views of the manifold with connections placed one above another illustrated in  FIG. 4   b.    
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner. 
         [0030]    The block diagram of  FIG. 1  shows a prior art HVAC usable to condition air in a vehicle. Such an HVAC has a refrigerant circuit system  1  employing a suitable refrigerant. From a compressor  2  the refrigerant flows through the refrigerant line  3  on the high-pressure side to a gas cooler  4 , where the refrigerant is cooled by an environmental air flow. Then the refrigerant flows over the high-pressure entrance  5  into the internal heat exchanger  6  and after having passed the internal heat exchanger  6 , over a high-pressure exit  7  to a manifold connection  8 . The manifold connection  8  is placed on the refrigerant line  3 , whereby the manifold  9  established as three-way screwing point divides the refrigerant line  3  into two branches  10 ,  11 , which run parallel to each other. In each of the branches  10 ,  11 , first, an expansion member  12 ,  13 , respectively, is disposed downstream into which after having passed the manifold  9 , the refrigerant flows. In both branches  10 ,  11  of the refrigerant line  3 , the expanding refrigerant is directed to an evaporator  14 ,  15 . Both branches  10 ,  11  of the refrigerant line  3  then lead from each of the evaporators  14 ,  15  over two different entrances  16 ,  17  into a collector  18  or accumulator, where the refrigerant is intermediately stored, before it can flow over the low-pressure entrance  19  into the internal heat exchanger  6  and from there over the low-pressure exit  20  into the compressor  2  again. 
         [0031]      FIG. 2  shows a block diagram of an HVAC which is usable to condition air in a vehicle according to the present invention. The HVAC is provided with a refrigerant circuit system  21  employing a suitable refrigerant. From a compressor  22  the refrigerant flows through the refrigerant line  23  on the high-pressure side to a gas cooler  24 , where the refrigerant is cooled by an environmental air flow. Then the refrigerant flows over the high-pressure entrance  25  into the internal heat exchanger  26 , which is part of the combined component  27  which includes a accumulator  28  or accumulator and the internal heat exchanger  26 . At a manifold  29 , which includes two double connection elements  30 ,  31 , the high-pressure exit of the internal heat exchanger  26  is divided into two single high-pressure exits  32 ,  33 , which lead to two parallel branches  34 ,  35  of the refrigerant line  23 . The first high-pressure exit  32  leading out of the internal heat exchanger  26  leads over the double connection element  30  into the first branch  34  of the refrigerant line  23 . The second high-pressure exit  33  leading out of the internal heat exchanger  26  leads over the second double connection element  31  into the second branch  35  of the refrigerant line  23 . In each of the branches  34 ,  35 , the refrigerant is led to an expansion member  36 ,  37 , respectively. From the expansion members  36 ,  37  the expanded refrigerant reaches a first evaporator  38  and a second evaporator  39 , respectively. From the parallel switched evaporators  38 ,  39  the refrigerant line  23  again leads to the double connection elements  30 ,  31  of the manifold  29 , respectively. Over the first low-pressure entrance  40  at the first double connection element  30  and over the second entrance  41  at the second double connection element  31 , the refrigerant line  23  leads the refrigerant into the accumulator  28  of the combined component  27  and over the low-pressure exit  42  the refrigerant can reach the compressor  22  again so that the refrigerant circuit system  21  is closed. 
         [0032]    In  FIG. 3   a,  a branch portion of the refrigerant line  3  according to prior art is shown, which provides the connection of the collector  18  and the internal heat exchanger  6 , as well as to the parallel switched evaporators  14 ,  15  and the expansion members  12 ,  13  in both branches  10 ,  11  of the refrigerant line  3 . Downstream of the high-pressure exit  7  of the internal heat exchanger  6 , the manifold  9  that is established as a first three-way screwing point is disposed. The connection of the manifold  9  to the high-pressure exit  7  of the internal heat exchanger  6  is made through the refrigerant line  3  over the manifold connection  8 . On the manifold  9  there is a screwing point  44 . The manifold  9 , as is seen in  FIG. 3   a,  divides the refrigerant line  3  into the first branch  10  and the second branch  11 . Both branches  10 ,  11  of the refrigerant line  3  end in a second three-way screwing point leading to the manifold  43 . From the manifold  43  the re-united refrigerant line  3  leads into an entrance of the collector  18 . From the collector  18 , another portion of the refrigerant line  3  leads over the low-pressure entrance  19  into the internal heat exchanger  6 . As shown in  FIG. 3   a,  in this branching portion six screwing points  44  are used, whereby screwing points are used at each of the manifolds  9 ,  43  on the refrigerant line  3 . This requires one additional screwing process on each the high-pressure side and the low-pressure side. 
         [0033]    In  FIG. 3   b,  another embodiment of the branching portion of the refrigerant line  3  according to the prior art is shown. In this embodiment, the branching portion facilitates the connection between the collector  18  and the internal heat exchanger  6 , as well as between the parallel switched evaporators and expansion members in both branches  10 ,  11 . 
         [0034]    In this embodiment, as opposed to the embodiment in  FIG. 3   a,  three of two screwing points  44  are established directly on the collector  18 . Both branches  10 ,  11  of the refrigerant line  3  lead to the two different entrances  16 ,  17  to the collector  18 . For fastening of the refrigerant line  3  to the entrances  16 ,  17 , two of the three screwing points  44  on the collector  18  are provided. Also, the connection line from the collector  18  to the low-pressure entrance  19  of the internal heat exchanger  6  starts, for which another of the three screwing points  44  at the collector  18  is provided. Also in this embodiment of the branching portion, which also corresponds to the arrangement in the block diagram according to  FIG. 1 , six screwing points  44  altogether are required, whereby one screwing point  44  is placed on the manifold  9  on the refrigerant line  3 . 
         [0035]      FIG. 4   a  shows the combined component  27  including the accumulator  28  and the internal heat exchanger  26  including the manifold  29  which provided with double connection elements  30 ,  31  that are arranged in parallel opposite to each other and with screwing points  44 . The manifold  29  connects the combined component  27  to the two branches  34 ,  35  which are switched in parallel to each other from the refrigerant line  23 . The second branch  34  of the refrigerant line  23  starts at the first high-pressure exit  32  and ends at the first low-pressure entrance  40 . Fastening of the first branch  34  of the refrigerant line  23  to the high-pressure exit  32  and the first low-pressure entrance  40  is facilitated over the first double connection element  30 . Fastening of the second branch  35  of the refrigerant line  23  to the second high-pressure exit  33  and to the second low-pressure entrance  41  is facilitated over the second double connection element  31 . The double connection elements  30 ,  31 , according to  FIG. 4   a,  include one screw for the screwing point  44 . Due to the use of the double connection elements  30 ,  31  the number of screwing points  44  can be reduced from six as required by prior art according systems as shown in  FIG. 3   a  and  FIG. 3   b  to two as shown in  FIG. 4   a.    
         [0036]      FIG. 4   b  shows the combined component  27  including the accumulator  28  and the internal heat exchanger  26  including the manifold  29  in a similar arrangement as in  FIG. 4   a,  but wherein the double connection elements  30 ,  31  and the two screwing points  44  are arranged in parallel above each other on one side of the combined component  27  rather than in parallel opposite to each other as shown in  FIG. 4   a.    
         [0037]    Due to the arrangements of the invention according to  FIGS. 4   a  and  4   b,  the number of screwing points  44  is reduced to two but further, compared with prior art as shown in  FIGS. 3   a  and  3   b,  interconnection of the refrigerant line  3  is substantially simplified. 
         [0038]      FIG. 5  shows a detailed view of the manifold  29  with connections in parallel opposite to each other as shown in  FIG. 4   a,  without the double connection elements  30 ,  31  shown. The manifold  29  as a substantially rectangular placed-on body arranged on a cover  45  of the combined component  27  including the internal heat exchanger  26  and the accumulator  28 .  FIG. 5   a  shows a side view of the manifold  29 , which in this view appears as a rectangular, centrally positioned body placed on the cover  45 . Along a central cylinder axis  46  of the combined component  27 , the axis  46  running perpendicularly to a circular cover plate  47  of the cover  45 , the right-side side view, according to  FIG. 5   a,  is substantially symmetrical. 
         [0039]      FIG. 5   b  shows a top view of the cover plate  47 . Two longitudinal edges  48  of the manifold  29  run parallel, on both sides substantially equally distanced to a mirror symmetry axis  49  of the cover plate  47 . An inner edge  50  of the manifold  29  runs perpendicular to both longitudinal edges  48  of the manifold  29  and to the mirror symmetry axis  49  of the cover plate  47 , wherein the mirror symmetry axis  49  intersects the inner edge  50  of the manifold  29  at the center. An outer edge  51  of the manifold  29  is rounded in such a form that, as shown in the view in  FIG. 5   b,  the outer edge  51  is congruent to a cover edge  52 . As shown in  FIG. 5   b,  the length of the longitudinal edges  48  of the manifold  29  is longer than a radius of the cover  45 , but shorter than a diameter of the cover  45 . The manifold  29  is arranged asymmetrically with respect to an axis  53  of the cover plate  47 , the axis  53  being perpendicular to the mirror symmetry axis  49 . 
         [0040]      FIG. 5   c  shows a front view of the manifold  29 . As shown, the manifold  29  on a longitudinal side surface  54  is provided with a central, small circular screw hole  55  and on both sides thereof, two bigger circular holes  56 ,  57 , wherein the low-pressure entrance hole  56  is on the one side and the high-pressure exit hole  57  is on the other side, the centers of which are on a common horizontal axis  58 . The smaller central screw hole  55  establishes the screwing point  44  of a double connection element  30 ,  31 . The wider low-pressure entrance hole  56 , positioned approximately in the central region of the cover  45 , serves as the entrance hole for the refrigerant at low pressure. The high-pressure exit hole  57 , located in the edge region of the cover  45 , serves as an exit hole for the refrigerant from the internal heat exchanger  26  at high pressure. 
         [0041]      FIG. 5   d  and  FIG. 5   e,  taken along the cutting planes A-A and B-B in  FIG. 5   c,  respectively, show sections along the cutting plane A-A and B-B, respectively, of the connection block seen in a direction parallel to the cylinder axis  46  of the combined component  27 . As shown in  FIG. 5   d,  each of the longitudinal side surfaces includes a low-pressure entrance hole  56 . 1 ,  56 . 2  and a high-pressure exit hole  57 . 1 ,  57 . 2 . The sectional view in  FIG. 5   d  also shows an internal low-pressure entrance manifold  59  and an internal high-pressure exit manifold  60 . The inner low-pressure manifold  59  facilitates the connection of the two low-pressure entrance holes  56 . 1 ,  56 . 2  to the accumulator  28  of the combined component  27 . In the center of a hollow channel  61 . 1 , which extends from the first low-pressure entrance hole  56 . 1  to the second low-pressure entrance hole  56 . 2 , a fusion channel  62  is arranged perpendicular to the hollow channel  61 . 1 , in such a way that refrigerant flowing in from the low-pressure entrance holes  56 . 1 ,  56 . 2  is brought together in the fusion channel  62 . 
         [0042]    The inner high-pressure exit manifold  60  facilitates the connection of the two high-pressure exit holes  57 . 1 ,  57 . 2  to the internal heat exchanger  26  of the combined component  27 . In the center of the hollow channel  61 . 2 , which extends from the first high-pressure exit hole  57 . 1  to the second high-pressure exit hole  57 . 2 , there is a circular hole of the connection channel  63  which runs perpendicular to the hollow channel  61 . 2 , wherein the circular hole leads to the pipe of the internal heat exchanger  26 . 
         [0043]    The T-shaped arrangement of the internal low-pressure entrance manifold  59  is shown in  FIG. 5   e  by a sectional view along the cutting plane B-B according to  FIG. 5   c.  The hollow channel  61 . 1 , which extends from the first low-pressure entrance hole  56 . 1  up to the second low-pressure entrance hole  56 . 2 , is divided in the center by the fusion channel  62 , which is positioned perpendicular to the hollow channel  61 . 1 . The fusion channel extends from the hollow channel  61 . 1  through the interior of the cover  45  up to an inner surface of the cover  45 . 
         [0044]      FIG. 5   f  shows an isometric representation of the cover  45  with a manifold  29 , which on each of both longitudinal side surfaces  54  is provided with three different holes  55 ,  56 ,  57 . The manifold  29  is substantially rectangular, with the exception of an edge side surface  64  at the outer edge  51  of the manifold  29 , which is curved like the cover edge  52 . 
         [0045]    A detailed view of the manifold  29  with connections which are arranged parallel above another as shown in FIG.  4   b  is shown in  FIG. 6 . The manifold  29  is a substantially rectangular body placed on a cover  45  of the combined component  27  including the internal heat exchanger  26  and the accumulator  28 .  FIG. 6   a  shows a side view of the manifold  29 , which in this view appears as a substantially rectangular body disposed off center from the cover  45 . The connection block  29  of  FIG. 6  is narrower and higher than the connection block  29  shown in  FIG. 5 . 
         [0046]      FIG. 6   b  shows a top view of a cover plate  47 . Both longitudinal edges  65 ,  66  of the manifold  29  run parallel to an axis  68  of the cover  45 . An inner edge  67  of the manifold  29  runs perpendicular to both longitudinal edges  65 ,  66  and the axis  68  of the cover  45 . The axis  68  of the cover  45  intersects the inner edge  67  outside of the center of the inner edge  67 . An outer edge  69  of the manifold  29 , however, is curved in such a form that, as shown in the top view in  FIG. 6   b,  the outer edge  69  is congruent to a cover edge  52 . According to  FIG. 6   b,  the length of the longitudinal edges  65 ,  66  is longer than a radius of the cover  45 , but shorter than a diameter of the cover  45 . 
         [0047]      FIG. 6   c  shows a front view of the manifold  29  according to this embodiment of the invention. The manifold  29  on a longitudinal side surface  70  includes two central, small circular screw holes  71  formed above each other and on either side of two wider circular holes  72 ,  73 , which are formed above each other. The wider holes  72 ,  73  formed above each other, on the one side, being low-pressure entrance holes  72  and, on the other side, high-pressure exit holes  73 . Centers of the three upper circular holes  71 ,  72 ,  73  are located on a common upper horizontal axis  74  and centers of the three lower circular holes  71 ,  72 ,  73  are located on a lower horizontal axis  75 , which is parallel to the upper horizontal axis  74 . The smaller central screw holes  71  establish the screwing point  44  of double connection elements  30 ,  31 . The bigger low-pressure entrance holes  72  formed above each other, which are formed approximately in the central region of the cover  45 , serve as entrance holes for the refrigerant at low pressure. Both high-pressure exit holes  73  formed above each other, which are located in the edge region of the cover  45 , serve as exit holes for the refrigerant from the internal heat exchanger  26  at high pressure. 
         [0048]    Referring to the identification of the cutting planes A-A and B-B, respectively, of  FIG. 6   c,  in  FIG. 6   d  a section along the cutting plane A-A of the connection block  29  is shown in direction parallel to the cylinder axis  46  of the combined component  27 . As shown in  FIG. 6   d,  only on the longitudinal side surface  70  below the longitudinal edge  65  are holes  71 ,  72 ,  73 . The sectional view in  FIG. 6   d  shows an internal low-pressure entrance manifold  76  and an internal high-pressure exit manifold  77 . The inner low-pressure manifold  76  connects the two low-pressure entrance holes  72  to the accumulator  28  of the combined component  27 . Short entrance channels  78  lead into a fusion channel  79 , which is positioned perpendicular to the entrance channels  78 , in such a way that refrigerant flowing in from both low-pressure entrance holes  72  is brought together in the fusion channel  79 . 
         [0049]    The inner high-pressure exit manifold  77  connects the two high-pressure exit holes  73  to the internal heat exchanger  26  of the combined component  27 . The short entrance channels  78  lead into a connection channel  80  which is positioned perpendicular to the entrance channels  78 . 
         [0050]    The F-shaped arrangement of the internal low-pressure entrance manifold  76  is shown in  FIG. 6e  as a sectional view along the cutting plane B-B shown in  FIG. 6   c.  The entrance channels  78  lead into the connection channel  80 , which is aligned perpendicular to the entrance channels  78 , wherein the connection channel  80  extends through an interior of the cover  45  up to an inner surface of the cover  45 . 
         [0051]      FIG. 6   f  shows an isometric representation of the cover  45  with a manifold  29  which is provided with holes  71 ,  72 ,  73  only on the longitudinal side surface  70  below the longitudinal edge. The manifold  29  is substantially rectangular, with the exception of the edge side surface  64  below the outer edge  69  of the manifold  29 , the edge side surface  64  being curved like the cover edge  52 . 
         [0052]    From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.