Abstract:
A reciprocating compressor of a type includes a cylinder block having a plurality of bores disposed in parallel with each other, a valve plate having suction ports corresponding to the respective bores, a cylinder head for closing the outer end of the cylinder block through the valve plate which is held between the cylinder head and the cylinder block and on which suction valves and discharge valves are mounted, a suction chamber formed in the cylinder head adjacent to a refrigerant introduction port, and pistons inserted into the respective bores so as to reciprocate in a predetermined phase difference. In the reciprocating compressor, partitions are disposed in the cylinder head around the outer periphery of the suction chamber for introducing suction gas into the respective bores.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a compressor preferably applied to automotive air conditioning, and more particularly, to a multi-cylinder reciprocating compressor including single-head-type pistons.  
           [0003]    2. Description of the Related Art  
           [0004]    Hitherto, reciprocating compressors are used for a refrigerating circuit and the like of automotive air conditioners. A conventional reciprocating compressor includes a cylinder block having a plurality of cylinder bores in which pistons are accommodated and a front housing disposed at an end of a casing. A cylinder head is disposed at the other end of the cylinder block of the casing through a valve plate unit. Further, the compressor includes a rotating shaft inserted into the cylinder block of the casing passing through the front housing, a rotor disposed sequentially from a side near to the front housing of the rotating shaft, a swash plate, and a swing plate. An end of the rotor is rotatably supported by the inner wall of the front housing and the other end thereof is coupled with an end of the swash plate disposed around the rotating shaft through a hinge mechanism. The swing plate is disposed around the cylindrical portion of the swash plate at the center thereof. The swing plate is swingable in an axial direction with respect to the swash plate but the rotation thereof around an axis is prevented. The pistons accommodated in the cylinder bores are connected to the other end of the swing plate in a vicinity of the periphery thereof through piston rods.  
           [0005]    Further, the cylinder head includes a first cylinder head unit and disposed outside of the compressor and a second cylinder head interposed between the first cylinder head unit and the valve plate unit. These first and second cylinder head units are fixed by bolts.  
           [0006]    The first cylinder head unit includes a bottom wall, a side wall disposed around the bottom wall and a partition disposed inside of the side wall. A refrigerant introducing through hole is formed through the bottom wall at the center thereof. The interior of the first cylinder head unit is widened and forms a suction chamber between it and the outside bottom surface of the second cylinder head unit. Further, a discharge port is formed at a position outwardly of the center of the bottom wall and the periphery of the discharge port is arranged as a boss section formed integrally with the partition. Further, a discharge chamber is formed between the side wall and the valve plate unit.  
           [0007]    In the conventional reciprocating compressor, when the rotating shaft is rotated by an external drive source, the rotor is rotated by the rotating shaft and the swash plate coupled with the rotor is rotated thereby. The rotation of the swash plate is converted into the axial reciprocating motions of the pistons in the cylinder bores through the swing motion of the swing plate and through the reciprocating motions of the piston rods.  
           [0008]    With this arrangement, refrigerant from an external refrigerant circuit is introduced into a suction room from the refrigerant introduction port through a suction chamber and reaches the cylinder bores from the suction room through suction ports. The refrigerant in the cylinder bores are compressed by the pistons and discharged into the discharge chamber from a discharge outlet. The compressed refrigerant discharged into the discharge chamber is supplied to the external refrigerant circuit through a discharge port.  
           [0009]    As described above, the conventional cylinder head has a series of partition for separating the inner space thereof into the suction room and the discharge chamber, and the suction room is arranged as a common suction space with no partition. Therefore, refrigerant gas introduced from the introduction port of the cylinder head is sequentially sucked into the respective bores from the suction port of a valve plate coupled with the cylinder block according to the suction stroke of the pistons.  
           [0010]    In the conventional suction gas paths, each of the paths from the refrigerant introduction port of the cylinder head to each of the suction ports of the respective bores has a different length, even if it is disposed on the center axis of the cylinder head, depending on various factors such as the position of the discharge port and the interference by reinforcing members. Moreover, the refrigerant gas is sucked in the common suction space, causing pressure pulsation in the suction gas by the mutual interference of the gas sucked into the respective bores.  
           [0011]    The pressure pulsation is transmitted to an evaporator in a compartment through piping, from which a problem arises in that unpleasant noise is generated by resonance.  
         SUMMARY OF THE INVENTION  
         [0012]    It is an object of the present invention to provide a cylinder head assembly capable of preventing noise in a compartment by preventing mutual interference of suction gas and by avoiding suction pulsation caused by pressure change.  
           [0013]    It is another object of the present invention to provide a reciprocating compressor including the above cylinder head assembly.  
           [0014]    It is still another object of the present invention to provide a cylinder head assembly which can be assembled simply.  
           [0015]    It is yet another object of the present invention to provide a reciprocating compressor including the above cylinder head assembly.  
           [0016]    According to an aspect of the present invention, there is provided a reciprocating compressor which includes a cylinder block having a plurality of bores disposed in parallel with each other, a valve plate having suction ports corresponding to the respective bores, a cylinder head for closing the outer end of the cylinder block through the valve plate which is held between the cylinder head and the cylinder block and on which suction valves and discharge valves are mounted, and pistons inserted into the respective bores so as to reciprocate in a predetermined phase difference, said cylinder head having a suction chamber formed in the cylinder head adjacent to a refrigerant introduction port, and partitions disposed in the cylinder head around the outer periphery of the suction chamber for introducing suction gas into the respective bores.  
           [0017]    According to another aspect of the present invention, there is provided a cylinder head assembly which is disposed at an end of a cylinder block having a plurality of cylinder bores of a compressor for closing the outer end of the cylinder block, and which includes a cylinder head main body acting as an outer shell, and a partition plate for constituting a discharge chamber. In the aspect of the present invnetion, the cylinder head main body comprises a refrigerant introduction port, a suction chamber disposed adjacent to the refrigerant introduction port, and partitions disposed in the cylinder head around the outer periphery of the discharge chamber for introducing suction gas into the respective bores. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    [0018]FIG. 1 is a sectional view showing a reciprocating compressor as an example of a conventional compressor;  
         [0019]    [0019]FIG. 2 is a sectional view showing a reciprocating compressor according to an embodiment of the present invention;  
         [0020]    [0020]FIG. 3A is a view showing a cylinder head of the reciprocating compressor of FIG. 2 when it is viewed from the side of a valve plate unit; and  
         [0021]    [0021]FIG. 3B is a sectional view taken along the line IIIB-IIIB of the cylinder head of FIG. 3A: 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    First, a conventional compressor will be described with reference to FIG. 1 for the easy understanding of the present invention prior to the description of a preferable embodiment of the present invention.  
         [0023]    Referring to FIG. 1, a reciprocating compressor  5  includes a cylinder block  11  formed integrally with a casing  9 . The cylinder block  11  includes a plurality of cylinder bores  7 . A front housing  13  is disposed at an end of the casing  9 . Further, the reciprocating compressor  5  includes a rotating shaft  17  that is inserted into the insert hole  15  of the cylinder block  11  in the casing  9  passing through the front housing  13 . The rotating shaft  17  is rotatably supported by the front housing  13  and the cylinder block  11  through bearings  19  and  21 . Further, a spring member  23  and a screw adjuster  25  are disposed to restrict thrust movement of the rotating shaft  17 . A rotor  27  is disposed to the rotating shaft  17  at a position thereof near to the front housing  13  and is fixed to the rotating shaft  17  by a bolt  29 . An end of the rotor  27  is supported by the inner wall of the front housing  13  through a thrust bearing  31 . Further, the other end of the rotor  27  is coupled with an end of a swash plate  33  disposed around the rotating shaft  17  through a hinge mechanism  35 . A swing plate  37  is disposed around the cylindrical portion of the swash plate  33  at the center thereof. The swing plate  37  is disposed so as to slide and rotate with respect to the swash plate  33  through a thrust bearing  39 . A groove is formed in a portion  41  of the swing plate  37 , and the groove is fitted to a rail plate  43  disposed in the casing  9  so as to move along an axial direction. A rotation preventing mechanism  45  is composed of the groove and the rail plate  43 .  
         [0024]    The rotation prevention mechanism  45  permits the swing plate  37  to move in a direction along the rotating shaft  17  but prohibits it to rotate around the rotating shaft  17 .  
         [0025]    Pistons  47  are disposed in the cylinder bores  7  of the cylinder block  11 . The pistons  47  are connected to the periphery of the swing plate  37  at the other end thereof through piston rods  49 .  
         [0026]    A cylinder head  53  is disposed at the other end of the cylinder block  11  of the casing  9  through a valve plate unit  51 .  
         [0027]    The valve plate unit  51  includes a valve plate main body  57  and a retainer  59 . The valve plate main body  57  has a suction valve (not shown) both the surfaces of which are formed integrally with seal members and a discharge valve  55 , and the retainer  59  is disposed so as to cover the discharge valve  55 . The retainer  59  is assembled by a bolt  61  so that it is integrated with the valve plate main body  57 .  
         [0028]    The cylinder head  53  includes a first cylinder head unit  63  disposed outside of the compressor and a second cylinder head  65  interposed between the first cylinder head unit  63  and the valve plate unit  51 .  
         [0029]    The first cylinder head unit  63  has a bottom wall  67  and a side wall disposed around the bottom wall  67  continuous to it. Further, a partition  71  is disposed internally of a side wall  69 . A through hole is formed through the bottom wall  67  at the center thereof and constitutes a refrigerant introduction hole  73  for introducing refrigerant. The interior of the bottom wall  67  is widened from the refrigerant introduction hole  73  and a suction chamber  75  is formed between the bottom wall  67  and the outer bottom surface of the second cylinder head  65 . Further, a discharge port  77  is formed through the bottom wall  67  at a position outwardly of the center thereof, and the periphery of the discharge port  77  is arranged as a boss section that is formed integrally with the partition  71 .  
         [0030]    The second cylinder head unit  65  has a partition  85  composed of a side wall  86  and a bottom wall  79 . A suction passage  80  is formed as a through hole provided in the partition  85  and extended from suction room  87  and a suction port  89 . A discharge chamber  81  is defined by the side wall  86 , the bottom wall  79 , and the valve plate unit  51 .  
         [0031]    The cylinder head  53  is coupled with the cylinder block  11  through bolts  83  screwed into the holes formed in the cylinder block  11 . Note that while the partition  85  is formed by the bottom wall  79  and the side wall  86  integrally formed, the bottom wall  79  and the side wall  86  may be partly or entirely formed as separate members.  
         [0032]    In the conventional reciprocating compressor arranged as described above, when the rotating shaft  17  is rotated by an external drive source (not shown), the rotor  27  is rotated by the rotating shaft  17  and, the swash plate  33  that is coupled with the rotor  27  is rotated thereby. The rotation of the swash plate  33  is converted into the reciprocating motions of the pistons  47  in the cylinder bores  7  through the swing motion of the swing plate  37  and through the reciprocating motion of the piston rods  49 .  
         [0033]    With this arrangement, the refrigerant is introduced from the refrigerant introduction hole  73  into a suction room  87  through the suction chamber  75 , reaches the cylinder bores  7  from the suction room  87  through the suction passage  80  and the suction port  89 , is compressed by the pistons  47 , discharged into a discharge room  81  through a discharge port  91 , and supplied to an external refrigerant circuit through the discharge port  77 .  
         [0034]    As described above, the conventional cylinder head  53  has the series of the partition for separating the inner space into the suction room  87  and the discharge room  81 , and the suction room  87  is arranged as a suction space without any partition. Accordingly, refrigerant gas introduced from the introduction port of the cylinder head is sequentially sucked into the respective bores  7  from the suction port of the valve plate unit  51  coupled with the cylinder block  11  according to the suction stroke of the pistons.  
         [0035]    Then, the embodiment of the present invention will be described with reference to FIGS. 2, 3A, and  3 B.  
         [0036]    Referring to FIG. 2, a reciprocating compressor  100  according to the embodiment of the present invention includes a cylinder block  11  having a plurality of cylinder bores  7  and formed integrally with a casing  9  and a front housing  13  disposed at an end of the casing  9 . Further, the reciprocating compressor  100  includes a rotating shaft  17  that is inserted into a insert hole  15  of the cylinder block  11  in the casing  9  passing through the front housing  13 . The rotating shaft  17  is rotatably supported by the front housing  13  and the cylinder block  11  through bearings  19  and  21  as well as restricted in an axial direction by a spring member  23  and a screw adjuster  25 . A rotor  27  is disposed to the rotating shaft  17  at a position thereof near to the front housing  13  and is fixed to the rotating shaft  17  by a bolt  29 . An end of the rotor  27  is supported by the inner wall of the front housing  13  through a thrust bearing  31 , and the other end thereof is coupled with an end of a swash plate  33  disposed around the rotating shaft  17  through a hinge mechanism  35 . A swing plate  37  is disposed around the cylindrical portion of the swash plate  33  at the center thereof so as to slide and rotate with respect to the swash plate  33  through a thrust bearing  39 . A groove is formed in a portion  41  of the periphery of the swing plate  37 , the groove is fitted to a rail plate  43  disposed in the casing  9  so as to move along an axial direction, and constitutes a rotation preventing mechanism  45  together with the rail plate  43 . The rotation prevention mechanism  45  permits the swing plate  37  to move in a direction along the rotating shaft  17  but prohibits it to rotate therearound.  
         [0037]    Pistons  47  are disposed in the cylinder bores  7  of the cylinder block  11  and connected to the periphery of the other end of the swing plate  37  through piston rods  49 .  
         [0038]    A cylinder head  91  is disposed at the other end of the cylinder block  11  of the casing  9  through a valve plate unit  51 .  
         [0039]    The valve plate unit  51  includes a valve plate main body  95  and retainers  59 . The valve plate main body  95  has suction valves (not shown) both the surfaces of which are formed integrally with seal members and discharge valves  93 , and the retainers  59  are disposed so as to cover the discharge valves  93 . They are assembled by a bolt  99  so that they are integrated with the valve plate main body  95 .  
         [0040]    The above arrangement of the reciprocating compressor  100  is substantially the same as that of the conventional reciprocating compressor  5  excepting a cylinder head.  
         [0041]    The cylinder head  91  according to the embodiment of the present invention includes a cylinder head main body  101  disposed outside of the reciprocating compressor  100  and a partition plate  103  interposed between the cylinder head main body  101  and the valve plate unit  51 .  
         [0042]    The cylinder head main body  101  is composed of a diecast aluminum and formed in a cup shape having a bottom wall and a side wall. A refrigerant introduction port  125  is formed through the bottom wall at the center thereof.  
         [0043]    Further, the partition plate  103  is interposed between the cylinder head main body  101  and the valve plate unit  51  and is composed of a reduced steel plate. A suction chamber  105  is formed between the partition plate  103  and the cylinder head main body  101 , whereas a discharge chamber  107  is formed between the partition plate  103  and the valve plate unit  51 . The suction chamber  105  is disposed downstream of the refrigerant introduction port  125  in communication therewith. A discharge port  111  is formed so as to pass through the partitions  109  of the cylinder head main body  101  from the discharge chamber  107  and to reach the outside. A seal member  113  is disposed to the portion where the discharge port  111  is connected to the partition plate  103  and the partitions  109  of the cylinder head  91 .  
         [0044]    As shown in FIGS. 3A and 3B, the partition plate  103  is formed by reducing a steel plate and includes a central bottom portion  115 , a side portion  117  formed from the bottom portion  115  along the periphery thereof, partition abutting portions  119  extending radially outwardly from the upper end of the side portion  117  and a ring-shaped outer peripheral portion  121  for connecting the outer ends of the partition abutting portions  119 .  
         [0045]    The discharge port  111  is formed through the bottom portion  115  of the partition plate  103  and further screw holes  123  are formed through the outer periphery of the partition plate  103  for fixing it by screws in cooperative to throghholes  135  provided into the cylinder head main body  101 .  
         [0046]    The partitions  109  are formed to the cylinder head main body  101  radially outwardly from a vicinity of a refrigerant introduction port  125 . The partition abutting portions  119  of the partition plate  103  are arranged so as to come into contact with the upper apex surface of the partitions  109 . A suction space is divided by the partitions  109 , and the respective divided suction spaces are disposed in correspondence to the respective cylinder bores  7  and form suction paths  127 , respectively.  
         [0047]    In the reciprocating compressor according to the embodiment of the present invention arranged as described above, when the rotating shaft  17  is rotated by an external drive source (not shown), the rotor  27  is rotated by the rotating shaft  17  and the swash plate  33  coupled with the rotor  27  is rotated thereby. The rotation of the swash plate  33  is converted into the axial reciprocating motions of the pistons  47  in the cylinder bores  7  through the swing motion of the swing plate  37  and the reciprocating motion of the piston rods  49 .  
         [0048]    As a result, refrigerant is introduced into the suction chamber  105  from the refrigerant introduction port  125 , reaches the cylinder bores  7  from the suction chamber  105  through the respective suction paths  127  and suction ports  129 , is compressed by the pistons  47 , discharged into the discharge chamber  107  from discharged ports  131 , and supplied to an external refrigerant circuit (not shown) through the discharge port  111 .  
         [0049]    After suction gas is introduced into the suction chamber  105 , it is introduced into the suction paths  127 , which are independent suction paths partitioned by the partitions  109  in correspondence to the respective cylinder bores  7 , and then introduced into the cylinder bores  7 . As a result, the mutual interference of the suction gas is prevented and pressure pulsation is attenuated.  
         [0050]    As described above, according to the cylinder head  91  of the embodiment of the present invention, after the suction gas is introduced into the suction chamber  105 , it is introduced into the suction paths, from which it is sucked into the respective cylinder bores  7  through the partitions  109 . As a result, the mutual interference of the suction gas is prevented and further the pressure losses from the refrigerant introduction port  125  to the respective bores and the distances of the flow paths therebetween are equalized, which can attenuate the pressure pulsation.  
         [0051]    In the embodiment of the present invention described above, the reciprocating compressor has the piston rods  49  one ends of which are connected to the swing plate  37  at the positions near to the outer periphery of the one surface thereof and the other ends of which are coupled with the pistons  47 . However, it is apparent that the present invention can be applied to a type of compressor which converts the motion of a rotating swash plate into the reciprocating motions of pistons through a shoe.  
         [0052]    Accordingly, in the present invention, since the suction gas paths through which the suction gas is sucked into the respective cylinder bores  7  are arranged as the independent paths by the partition, the mutual interference of the suction gas can be prevented and the pulsation of the suction gas caused by pressure change can be avoided. As a result, the reciprocating compressor  100  capable of preventing noise in a compartment can be provided.  
         [0053]    Further, according to the present invention, the cylinder head main body  101  is arranged independently of the partition plate, which makes it possible to provide the reciprocating compressor in which the complex refrigerant paths can be simply arranged and in which the cylinder head can be simply assembled.