Patent Publication Number: US-11384759-B2

Title: Vapor injection double reed valve plate

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This patent application claims priority to U.S. Provisional Patent Application Ser. No. 62/987,638, filed on Mar. 10, 2020, the entire disclosure of which is hereby incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention relates to a check valve assembly for preventing back flow and distributing fluid evenly to a scroll compressor with minimal flow losses. 
     BACKGROUND OF THE INVENTION 
     As is commonly known, vehicles typically include a heating, ventilating, and air conditioning (HVAC) system. In certain applications, a scroll compressor is employed for compressing a refrigerant circulated through a refrigerant circuit of the HVAC system. More specifically, such refrigerant circuits may be configured for use with a vapor injection scroll compressor that utilizes two different inputs of the refrigerant at different pressures and/or temperatures for optimizing the capacity of the vapor injection scroll compressor in comparison to single input scroll compressors. This is typically achieved by returning a portion of the refrigerant back towards the vapor injection scroll compressor after initially exiting the compression chambers of the vapor injection scroll compressor. Depending on the configuration of the refrigerant circuit, the returned refrigerant may be expanded via a corresponding expansion element, subcooled via a corresponding heat exchanger, or separated via a cyclone separator or the like, as well as any combinations thereof, prior to reentry back into the vapor injection scroll compressor to ensure that the returned refrigerant has the desired characteristics for the given application. 
     Generally, scroll compressors include a fixed scroll that remains stationary and an orbiting scroll that is nested relative to the fixed scroll and configured to orbit relative to the fixed scroll. The orbiting motion of the orbiting scroll, as well as the similar spiral shape of each of the fixed scroll and the orbiting scroll, continuously forms corresponding pairs of substantially symmetric compression chambers between the fixed scroll and the orbiting scroll. Each pair of the compression chambers is typically symmetric about a centralized discharge port of the vapor injection scroll compressor. Refrigerant typically enters each of the compression chambers via one or more inlet ports formed adjacent a radially outmost portion of the fixed scroll and then the orbiting motion of the orbiting scroll relative to the fixed scroll results in each of the compression chambers progressively decreasing in volume such that the refrigerant disposed within each of the compression chambers progressively increases in pressure as the refrigerant approaches the radially central discharge port. 
     The vapor injection scroll compressor is distinguished from traditional scroll compressors by injecting the returned refrigerant into each of the symmetrically formed compression chambers at a corresponding intermediate position disposed radially between the outwardly disposed inlet ports and the centrally disposed discharge port of the fixed scroll. Due to the presence of the pairs of the symmetric compression chambers between the cooperating scrolls, it is beneficial to introduce the returned refrigerant at two different injection openings that are similarly substantially symmetrically disposed relative to the centrally disposed discharge port such that each of the paired compression chambers receives a flow of the returned refrigerant at similar positions within the compression process. The injected refrigerant accordingly enters each of the compression chambers at a position corresponding to a region of the fixed scroll repeatedly subjected to a pressure of the radially inwardly flowing refrigerant that is generally intermediate the suction pressure formed at the inlet ports and the discharge pressure formed at the discharge port of the fixed scroll. The injected refrigerant originates from an injection chamber of the vapor injection scroll compressor configured to receive the returned refrigerant therein prior to reintroduction back into the compression chambers. 
     Additionally, the continuous orbiting of the orbiting scroll relative to the fixed scroll results in each of the injection openings formed in the fixed scroll being subjected to a variable pressure during each orbit of the orbiting scroll based on whether a corresponding portion of the orbiting scroll has passed by the corresponding injection opening with respect to each orbit cycle. It is therefore necessary for each of the injection openings of the fixed scroll to be associated with a corresponding check valve for ensuring that the returned refrigerant is injected into the corresponding compression chamber in a single flow direction. Specifically, the check valves ensure that the returned refrigerant can enter the corresponding compression chamber only when the refrigerant already disposed within the compression chamber is at a relatively low pressure that is lower than the pressure of the injected refrigerant. The check valve further prevents an occurrence wherein any compressed refrigerant at a relatively high pressure greater than that of the injected refrigerant flows in reverse (backflows) through the injection opening, through the injection chamber, and towards any components disposed upstream of the injection chamber with respect to the returned refrigerant, such as the aforementioned cyclone separator. 
     Such check valves may be provided as ball valves that are biased by a spring or the like to a closed position until the injected refrigerant pressure exceeds the pressure of the refrigerant present within the corresponding compression chamber. However, it has been discovered that the use of such ball valves may result in an undesirable pressure drop in the injected refrigerant that reduces the output capacity of the vapor injection scroll compressor. Other shortcomings of such ball valves may be the need for multiple components such that manufacturing complexity is increased, a need for increased axial packaging space for accommodating the motion of the ball relative to the spring, and an inconsistency of the distribution of the injected refrigerant to each of the pair of the injection openings. 
     Such a check valve may also be provided as a reed valve having a flexible metallic reed that flexes in response to a pressure differential thereacross. However, such reed valves are traditionally provided to include repeated metal to metal contact, which greatly reduces the durability of such reed valves and also introduces a concern of noise, vibration, and harshness (NVH) that can potentially be experienced by a passenger of a vehicle. 
     It would therefore be desirable to provide an improved and durable check valve mechanism to minimize back flow of the refrigerant, more evenly distribute the refrigerant between each of the injection openings when entering the corresponding compression chambers, and prevent an occurrence of NVH during operation thereof. 
     SUMMARY OF THE INVENTION 
     Consistent and consonant with the present invention, an improved check valve assembly for use with a vapor injection scroll compressor is disclosed. 
     According to an embodiment of the present invention, a valve assembly for a scroll compressor including a fixed scroll having a first injection port fluidly coupled to a compression mechanism of the scroll compressor is disclosed. The valve assembly includes a valve body having a first flow path formed therethrough with the first flow path fluidly coupled to the first injection port. An injection plate has a first injection hole formed therethrough. A reed structure is disposed between the injection plate and the valve body. The reed structure includes a first reed configured to selectively permit a fluid to flow through the first injection hole towards the first flow path for entry into the compression mechanism through the first injection port. 
     According to another embodiment of the present invention, a valve assembly forms a check valve for a scroll compressor including a fixed scroll having a pair of injection ports fluidly coupled to a compression mechanism of the scroll compressor. The valve assembly includes a valve body having a pair of flow paths formed therethrough with each of the flow paths fluidly coupled to a corresponding one of the injection ports. An injection plate has a pair of injection holes formed therethrough. A reed structure is disposed between the injection plate and the valve body with the reed structure including a pair of reeds. Each of the reeds is configured to selectively provide fluid communication between a corresponding one of the injection holes and a corresponding one of the injection ports. A valve gasket is disposed between the reed structure and the valve body and includes a pair of flaps with each of the flaps configured to selectively contact a corresponding one of the reeds. 
     According to yet another embodiment of the present invention, a vapor injection scroll compressor comprises a compression mechanism formed by the cooperation of a fixed scroll and an orbiting scroll. The compression mechanism is configured to compress a fluid therein. The fixed scroll includes a pair of injection ports formed therethrough with each of the injection ports in fluid communication with the compression mechanism. An injection chamber is configured to receive a portion of the fluid after being compressed within the compression mechanism. A valve assembly includes a reed structure having a pair of reeds. Each of the reeds is configured to selectively provide fluid communication between the injection chamber and a corresponding one of the injection ports. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above, as well as other objects and advantages of the invention, will become readily apparent to those skilled in the art from reading the following detailed description of an embodiment of the invention when considered in the light of the accompanying drawing which: 
         FIG. 1  is a cross-sectional elevational view taken through a compression mechanism of a scroll compressor according to an embodiment of the present invention; 
         FIG. 2  is an axial end elevational view of a fixed scroll of the compression mechanism of  FIG. 1  with the fixed scroll shown in isolation; 
         FIG. 3  is an exploded and partial cross-sectional perspective view of the relevant components of the scroll compressor necessary for illustrating an injection valve assembly of the scroll compressor; 
         FIG. 4  is a partially exploded perspective view of the injection valve assembly of  FIG. 3  with an injection plate thereof separated from a reed structure, a valve gasket, and a valve body thereof; 
         FIG. 5  is an axial end elevational view of the reed structure, the valve gasket, and the valve body shown in the absence of the injection plate; 
         FIG. 6  is a cross-sectional elevational view of the reed structure, the valve gasket, and the valve body as taken from the perspective of section lines  6 - 6  in  FIG. 5 ; 
         FIG. 7  is a fragmentary cross-sectional perspective view of the reed structure, the valve gasket, and the valve body as taken from the perspective of section lines  7 - 7  in  FIG. 5 ; 
         FIG. 8  is a partially exploded perspective view of an injection valve assembly according to another embodiment of the present invention with an injection plate thereof separated from a reed structure and a valve body thereof; 
         FIG. 9  is a perspective view of the reed structure and the valve body of the injection valve assembly of  FIG. 8 ; 
         FIG. 10  is an axial end elevational view of the reed structure and the valve body of the injection valve assembly of  FIG. 8 ; 
         FIG. 11  is a fragmentary cross-sectional perspective view of the reed structure and the valve body as taken from the perspective of section lines  11 - 11  in  FIG. 10 ; and 
         FIG. 12  is a fragmentary cross-sectional perspective view of the reed structure and the valve body as taken from the perspective of section lines  12 - 12  in  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description and appended drawings describe and illustrate various 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. 
       FIGS. 1-7  illustrate the relevant portions of a vapor injection scroll compressor  1  having an injection valve assembly  20  according to an embodiment of the present invention. As used hereinafter, the vapor injection scroll compressor  1  is referred to as the scroll compressor  1  while the injection valve assembly  20  is referred to as the valve assembly  20 . The scroll compressor  1  may be provided as a component of an HVAC system of a motor vehicle, and more particularly, a component for circulating a refrigerant of an associated refrigerant circuit in heat exchange communication with air to be delivered to the passenger compartment of the associated motor vehicle. The refrigerant may also be in heat exchange relationship with additional components of the motor vehicle in need of heat regulation, such as a battery or other electronic components associated with operation of various different systems of the motor vehicle. References to the refrigerant as used hereinafter may refer to a refrigerant when provided solely as a gas or as a mixture of a gas and a liquid. Although the scroll compressor  1  is described as being utilized for a refrigerant of an HVAC system, it should be apparent that the structure disclosed herein may be adapted for use with any fluid in need of compression with respect to any associated fluid system, as desired. 
     As best shown in cross-section in  FIG. 1 , the scroll compressor  1  includes a compression mechanism formed by a fixed scroll  5  having an axially extending first spiral structure  6  and an orbiting scroll  7  having an axially extending second spiral structure  8 . The second spiral structure  8  extends in an opposing axial direction relative to the first spiral structure  6  with each of the spirals of the second spiral structure  8  nested into each of the spaces formed between adjacent spirals of the first spiral structure  6 . The first spiral structure  6  and the second spiral structure  8  are positioned relative to each other to form a plurality of compression chambers  9  therebetween during operation of the compression mechanism of the scroll compressor  1 . 
     The fixed scroll  5  includes at least one inlet opening  11  adjacent a radially outermost portion thereof for introducing the refrigerant into each of the compression chambers  9 . In the provided embodiment, the fixed scroll  5  includes a plurality of the inlet openings  11  circumferentially spaced apart from each other in an outer circumferential wall  12  of the fixed scroll  5  with each of the inlet openings  11  provided as a hole, indentation, or other form of passageway allowing for radially inward flow of the refrigerant into one of the compression chambers  9 . The refrigerant generally enters the fixed scroll  5  through one of the inlet openings  11  at a relatively low pressure typically referred to as a suction pressure of the scroll compressor  1 . The fixed scroll  5  further includes a discharge opening  13  formed at a radial innermost end of the first spiral structure  6  through which the refrigerant exits each of the compression chambers  9  after having been compressed therein. The discharge opening  13  is accordingly located at or adjacent a radial center of the fixed scroll  5 . The compressed refrigerant thereby exits the cooperating scrolls  5 ,  7  at a relatively high pressure that is greater than the relatively low pressure suction pressure, wherein the relatively high pressure is referred to as the discharge pressure of the scroll compressor  1 . 
     The orbiting scroll  7  is configured to orbit relative to the fixed scroll  5  in a manner wherein each of the compression chambers  9  progresses circumferentially and radially inwardly towards the discharge opening  13 . A shape and position of each of the compression chambers  9  accordingly changes relative to the fixed shape and position of the fixed scroll  5  during the repeating orbiting motion of the orbiting scroll  7 . This motion causes each of the compression chambers  9  to reduce in flow volume as each of the compression chambers  9  approaches the radially inwardly disposed discharge opening  13 , thereby causing the previously discussed compression of the refrigerant. 
       FIG. 1  illustrates the cross-section through the fixed scroll  5  and the orbiting scroll  7  when the compression mechanism is at a position having two pairs of opposing compression chambers  9 . Each of the compression chambers  9  forming one of the pairs includes substantially the same shape rotated 180 degrees relative to the other of the paired and opposing compression chambers  9 . A first pair of the compression chambers  9  is disposed immediately adjacent a radial center of each of the spiral structures  6 ,  8  (generally corresponding to the position of the discharge opening  13 ) while a second pair of the compressions chambers  9  is formed radially outwardly of the first pair of the compression chambers  9  closer to the inlet openings  11 . 
     The fixed scroll  5  includes an end wall  14  including an inner face  15  and an opposing outer face  16 . The inner face  15  faces towards the orbiting scroll  7  with the first spiral structure  6  extending axially from the inner face  15 . The outer face  16  faces away from the orbiting scroll  7  and faces towards the previously mentioned valve assembly  20  (shown in  FIG. 3 ). The discharge opening  13 , a first injection port  17 , and a second injection port  18  are all formed through the end wall  14  from the inner face  15  to the outer face  16  thereof.  FIG. 2  shows the inner face  15  of the end wall  14  with the orbiting scroll  7  omitted to better illustrate the positioning of the discharge opening  13  and the injection ports  17 ,  18  relative to the configuration of the first spiral structure  6 . 
     The first injection port  17  is positioned substantially opposite the second injection port  18  relative to the centrally disposed discharge opening  13 , with each of the injection ports  17 ,  18  also spaced radially at a substantially equal distance from the discharge opening  13 . The substantially opposite positioning of the injection ports  17 ,  18  allows for the first injection port  17  to fluidly communicate with a first one of each of the oppositely paired compression chambers  9  and the second injection port  18  to fluidly communicate with a second one of each of the oppositely paired compression chambers  9 . As such, each of the compression chambers  9  progressing radially inwardly towards the discharge opening  13  is able to fluidly communicate with one of the injection ports  17 ,  18  at a substantially similar radial position relative to the discharge opening  13 , which also corresponds to the refrigerant disposed within each of the opposing and paired compression chambers  9  having a similar pressure when fluidly communicating with the corresponding one of the injection ports  17 ,  18 . The pressure of the refrigerant when reaching each of the injection ports  17 ,  18  may be referred to as an intermediate pressure having a value between the previously described suction pressure and discharge pressure. 
     Referring now to  FIG. 3 , the components of the scroll compressor  1  relevant to the operation of the valve assembly  20  are shown in exploded view for more easily ascertaining the method of assembly thereof. The orbiting scroll  7  and the components necessary for causing the orbiting motion thereof are omitted, but one skilled in the art should readily appreciate that the method of operation of the valve assembly  20  is apparent from the illustrated perspective in their absence. 
     A rear housing  110  of the scroll compressor  1  is an open ended and hollow structure configured to mate with a front housing (not shown) of the scroll compressor  1  for enclosing the internal components thereof. The rear housing  110  defines a housing opening  111  configured to receive the fixed scroll  5  and the valve assembly  20  therein. One skilled in the art should appreciate that alternative configurations of the housing components of the scroll compressor  1  may be provided so long as the relevant structures for directing the flow of the refrigerant are maintained as described hereinafter, including the use of additional housing components or the use of housing components having alternatively arranged joints present therebetween. More specifically, any combination of housing components may be utilized so long as the housing opening  111  is provided to receive the fixed scroll  5  and the valve assembly  20  therein in a manner promoting operation of the valve assembly  20  as disclosed hereinafter. 
     The housing opening  111  is in fluid communication with a refrigerant return passage  112 . The refrigerant return passage  112  provides fluid communication between the housing opening  111  and another component (not shown) of the associated refrigerant circuit through which the refrigerant is passed after being initially compressed within the compression mechanism of the scroll compressor  1 . For example, the component may be a separator (not shown) disposed downstream of the compression mechanism and upstream of a low pressure side of the scroll compressor  1  with respect to a general direction of flow of the refrigerant through the refrigerant circuit, such as a cyclone separator. The refrigerant return passage  112  is configured to receive a partial flow of the refrigerant after branching away from the refrigerant circuit. The partial flow of the refrigerant may have a pressure between the discharge pressure and the suction pressure and may bypass at least one component of the refrigerant circuit disposed upstream of the low pressure side of the scroll compressor  1 . In some instances, the component from which the refrigerant branches back towards the refrigerant return passage  112  may be disposed immediately downstream of the compression mechanism and even from a downstream arranged portion of the scroll compressor  1  itself. One skilled in the art should appreciate that the refrigerant may return to the refrigerant return passage  112  from any component of the refrigerant circuit while remaining within the scope of the present invention so long as the refrigerant has the required characteristics for being injected back into the compression chambers  9  during the compression process occurring within the compression mechanism. 
     The refrigerant return passage  112  leads to an injection chamber  113  of the rear housing  110 . The injection chamber  113  is an open space provided as a portion of the housing opening  111  disposed between the refrigerant return passage  112  and the valve assembly  20 . The refrigerant entering the injection chamber  113  may be a gaseous vapor or a combination of a gaseous vapor and a liquid, depending on the circumstances of the returned refrigerant. 
     A first gasket  115  is disposed between a periphery of the outer face  16  of the fixed scroll  5  and an inner surface of the rear housing  110  defining the housing opening  111  thereof. The fixed scroll  5  is received into the housing opening  111  with the first gasket  115  compressed between the outer face  16  and the inner surface of the rear housing  110  for creating a seal in a manner wherein refrigerant cannot flow around a periphery of the fixed scroll  5  to isolate the injection chamber  113  and the valve assembly  20  from the low pressure side of the scroll compressor  1 . The valve assembly  20  is disposed between the outer face  16  and the refrigerant return passage  112  with the outwardly facing surfaces thereof exposed to the refrigerant entering the injection chamber  113  through the refrigerant return passage  112 . 
     The valve assembly  20  includes an injection plate  22 , a double reed structure  30 , a valve gasket  50 , and a valve body  80 , wherein the components are disposed in the provided order when progressing from the refrigerant return passage  112  towards the fixed scroll  5 . The direction of assembly of the valve assembly  20  as shown by the direction of separation of the components forming the valve assembly  20  in the exploded view of  FIG. 3  is hereinafter referred to as an axial direction of the valve assembly  20 . The axial direction of the valve assembly  20  also corresponds to the axial direction of each of the constituent components thereof as used hereinafter. 
     The injection plate  22  includes a substantially planar first major surface  23  and an oppositely arranged and also substantially planar second major surface  24 , wherein the major surfaces  23 ,  24  are arranged parallel to each other and perpendicular to the axial direction of the valve assembly  20 . The first major surface  23  faces towards the refrigerant return passage  112  and the second major surface  24  faces towards the reed structure  30  and the valve gasket  50 . 
     The injection plate  22  includes a first injection hole  25  and a spaced apart second injection hole  26 . Each of the injection holes  25 ,  26  extends through the injection plate  22  with respect to the axial direction from the first major surface  23  to the second major surface  24  thereof. A spacing between the injection holes  25 ,  26  with respect to a direction perpendicular to the axial direction may be substantially similar to or equal to a spacing between the first injection port  17  and the second injection port  18  formed through the fixed scroll  5 . 
     Each of the injection holes  25 ,  26  is shown as having an elongated perimeter shape with a direction of elongation of each of the injection holes  25 ,  26  arranged in parallel. The injection holes  25 ,  26  may otherwise be referred to as injection slots  25 ,  26  due to the elongated configurations thereof. Each of the injections holes  25 ,  26  is shown as having an elongate stadium shape, but other rounded and elongate shapes may be utilized such as an elliptical shape, oval shape, rounded rectangular shape, or the like. The elongate shape of each of the injection holes  25 ,  26  beneficially provides for an increased cross-sectional flow area therethrough in comparison to a purely circular cross-sectional shape, which in turn increases the total force that can be applied by the returned refrigerant through each of the injection holes  25 ,  26  with respect to a given pressure of the refrigerant. However, other shapes, including the circular shape, may be utilized while still appreciating the remaining beneficial characteristics of the valve assembly  20 . 
     A second gasket  116  is disposed between a periphery of the first major surface  23  and the inner surface of the rear housing  110  defining the housing opening  111 . The second gasket  116  provides a seal between the injection plate  22  and the rear housing  110  to prevent refrigerant from bypassing the flow paths formed through the valve assembly  20  and fluidly communicating with the compression chambers  9  of the scrolls  5 ,  7 . 
     The injection plate  22  is generally rectangular in shape with each of the four corners of the rectangular shape including a fastener opening  27  formed therethrough. The fastener openings  27  are disposed outwardly from a position of the perimeter of the second gasket  116  when sealingly engaging the injection plate  22 . As shown in  FIG. 3 , each of the fastener openings  27  is configured to axially receive a corresponding threaded fastener  117  for coupling and compressing the components of the valve assembly  20  together as explained in greater detail hereinafter. An end of each of the threaded fasteners  117  may be inserted into one of four corresponding threaded openings (not shown) provided in the surface of the rear housing  110  defining the housing opening  111 . Alternative coupling methods may also be utilized so long as the components forming the valve assembly  20  are compressed to one another for forming the necessary fluid tight seals therebetween while maintaining the relationships between the components as explained hereinafter. 
     The injection plate  22  also includes a pair of spaced apart locating openings  28  formed therethrough. Each of the locating openings  28  is configured to receive a corresponding locating feature  118  therethrough when the valve assembly  20  is in the assembled configuration. The locating features  118  may be threaded fasteners, pins, or the like. The use of two of more of the locating openings  28  ensures that the components of the valve assembly  20  do not translate in a direction perpendicular to the axial direction thereof or rotate about an axis arranged parallel to the axial direction thereof. However, other locating features such as cooperating projections and indentations may be present within the components forming the valve assembly  20  while remaining within the scope of the present invention. 
     The injection plate  22  is formed from a rigid material resistant to deformation when subjected to the pressure applied by the returned refrigerant entering the injection chamber  113 . The injection plate  22  may be formed from a metallic material such as aluminum, aluminum alloy, steel, or the like, as desired. 
     The double reed structure  30  is a thin and planar plate-like body including a first major surface  31  and an oppositely arranged second major surface  32  (best shown in  FIG. 6 ). The major surfaces  31 ,  32  are arranged parallel to each other and perpendicular to the axial direction of the valve assembly  20 . The first major surface  31  is configured to face towards and engage the second major surface  24  of the injection plate  22  and the second major surface  32  is configured to face towards and engage the valve gasket  50  as explained in greater detail hereinafter. 
     The double reed structure  30  includes a first reed  33 , a second reed  34 , and a connecting portion  35 . The reeds  33 ,  34  and the connecting portion  35  are integrally formed as one monolithic structure. The first reed  33  and the second reed  34  normally extend longitudinally away from the connecting portion  35  in opposing parallel directions perpendicular to the axial direction of the valve assembly  20  when the reeds  33 ,  34  are not flexed during operation of the scroll compressor  1 . In the provided embodiment, the reeds  33 ,  34  and the connecting portion  35  cooperate to have a substantially Z-shaped configuration, but the connecting portion  35  may have any shape or configuration so long as the connecting portion  35  extends between and connects the reeds  33 ,  34  to form the described unitary structure with the reeds  33 ,  34  arranged in the illustrated staggered configuration. 
     The first reed  33  includes an arm  37  extending longitudinally between a pivot portion  38  and an end portion  39 . The pivot portion  38  forms an axis about which the remainder of the first reed  33  (including the end portion  39  disposed at a distal end of the arm  37  opposite the pivot portion  38 ) flexes relative to the stationary connecting portion  35 . The end portion  39  is disposed in alignment with the first injection hole  25  of the injection plate  22  with respect to the axial direction of the valve assembly  20 . The arm  37  may include a substantially rectangular shape while the end portion  39  may include a substantially similar perimeter shape to the first injection hole  25 . For example, the end portion  39  may include an elongate stadium shape, elliptical shape, oval shape, rounded rectangular shape, or the like to ensure that the end portion  39  is capable of covering the first injection hole  25  when engaging the injection plate  22  around a periphery of the first injection hole  25 . 
     The second reed  34  includes an arm  41  extending longitudinally between a pivot portion  42  and an end portion  43 . The pivot portion  42  forms an axis about which the remainder of the second reed  34  (including the end portion  43  disposed at a distal end of the arm  41  opposite the pivot portion  42 ) flexes relative to the stationary connecting portion  35 . The end portion  43  is disposed in alignment with the second injection hole  26  of the injection plate  22  with respect to the axial direction of the valve assembly  20 . The arm  41  may include a substantially rectangular shape while the end portion  43  may include a substantially similar perimeter shape to the second injection hole  26 . For example, the end portion  43  may include an elongate stadium shape, elliptical shape, oval shape, rounded rectangular shape, or the like to ensure that the end portion  43  is capable of covering the second injection hole  26  when engaging the injection plate  22  around a periphery of the second injection hole  26 . 
     The double reed structure  30  further includes a pair of locating openings  48  disposed in outwardly disposed regions of the connecting portion  35  formed at opposing corners thereof. Each of the pair of the locating openings  48  is disposed in alignment with a corresponding one of the locating openings  28  of the injection plate  22 . Each of the locating openings  48  is configured to receive a corresponding one of the locating features  118  therethrough when the valve assembly  20  is in the assembled configuration to properly position the double reed structure  30  relative to the injection plate  22  as well as the valve gasket  50 . 
     The double reed structure  30  is formed from a resiliently flexible material allowing for each of the arms  37 ,  41  of the reeds  33 ,  34  to flex about the respective pivot portions  38 ,  42  away from the plane generally defined by the double reed structure  30 . The resiliently flexible material is selected to allow for repeated elastic deformations of each of the reeds  33 ,  34  about the pivot portions  38 ,  42  while still allowing for each of the reeds  33 ,  34  to spring back to the original positions thereof wherein the reeds  33 ,  34  are arranged perpendicular to the axial direction of the valve assembly  20  and parallel to the major surfaces  31 ,  32  of the connecting portion  35  of the double reed structure  30 . The flexing of each of the reeds  33 ,  34  away from the corresponding injection hole  25 ,  26  requires a force being applied to each of the reeds  33 ,  34  that overcomes a spring force generated by the resiliency of each of the reeds  33 ,  34  at each of the corresponding pivot portions  38 ,  42 . The double reed structure  30  may accordingly be formed from a suitable metallic material such as aluminium, steel, or alloys thereof. 
     The valve gasket  50  includes a planar portion  51  having a thin and plat-like configuration with the planar portion  51  having a first major surface  53  and an oppositely arranged second major surface  54  (best shown in  FIG. 6 ), each of which is arranged substantially perpendicular to the axial direction of the valve assembly  20 . The first major surface  53  is configured to face towards and sealingly engage the second major surface  32  of the double reed structure  30  and the second major surface  54  is configured to face towards and sealingly engage a first major surface  81  of the valve body  80  ( FIG. 6 ). More specifically, the first major surface  53  of the planar portion  51  is configured to sealingly engage the stationary and non-flexing connecting portion  35  of the double reed structure  30 . The first major surface  53  further includes a bead  52  projecting axially from a periphery thereof with the bead  52  configured to sealingly engage the second major surface  24  of the injection plate  22  about a periphery thereof. The bead  52  engages the second major surface  24  peripherally to surround the injection holes  25 ,  26  and the locating openings  28  of the injection plate  22 . The bead  52  projects from the remainder of the first major surface  53  a suitable axial distance to account for the thickness of the intervening double reed structure  30  when establishing the engagement with the injection plate  22 . 
     The valve gasket  50  further includes a first flap  55  and a second flap  65 , each of which extends from and is formed continuous with the planar portion  51  of the valve gasket  50 . In other words, the planar portion  51 , the first flap  55 , and the second flap  65  are all formed integrally as part of a unitary and monolithic structure. The first flap  55  and the second flap  65  each extend away from the planar portion  51  in opposing and parallel directions. The first flap  55  is aligned with the first reed  33  with respect to the axial direction of the valve assembly  20  and the second flap  65  is aligned with the second reed  34  with respect to the axial direction of the valve assembly  20 . 
     The first flap  55  includes a proximate end  56  connected to and continuous with the planar portion  51  and a freely disposed distal end  57 . The first flap  55  further includes a contact surface  58  ( FIG. 6 ) formed continuous with the first major surface  53  of the planar portion  51  with the contact surface  58  facing towards the first reed  33  of the double reed structure  30 . The first flap  55 , and more specifically the contact surface  58  thereof, is arranged at an incline relative to the plane of the planar portion  51  with the first flap  55  inclined away from the injection plate  22  and towards the valve body  80 . The incline includes an axial distance present between the contact surface  58  and the connecting portion  35  of the double reed structure  30  progressively increasing as the first flap  55  extends from the proximate end  56  to the distal end  57 . The contact surface  58  is configured to engage the first reed  33  when the first reed  33  is flexed or pivoted towards the contact surface  58  as a result of the pressure applied thereto by the refrigerant passing through the valve assembly  20 . The contact surface  58  may include a substantially similar shape to the first reed  33  and may include a slightly larger size than the first reed  33  to ensure that the first reed  33  makes consistent contact with the contact surface  58  each time the first reed  33  is flexed towards the contact surface  58 . The incline of the contact surface  58  may be substantially constant, but may also include a slight curvature to account for any curvature present in the first reed  33  as a result of the flexing thereof. The incline of the contact surface  58  may be at an angle of about 3-5 degrees relative to the plane of the planar portion  51 , but other angles of inclination may be utilized while remaining within the scope of the present invention. 
     As best shown in  FIG. 5 , the inclined deviation of the first flap  55  from the planar portion  51  includes the formation of a peripheral opening  60  around at least a portion of the perimeter of the first flap  55 . The peripheral opening  60  is configured to allow for passage of the refrigerant through the valve gasket  50  when progressing towards the valve body  80 . In the provided embodiment, the peripheral opening  60  is subdivided into a pair of proximate openings  61  adjacent the proximate end  56  and a distal opening  62  extending around the distal end  57 , wherein the distal opening  62  is separated from the proximate openings  61  via a pair of opposing linking segments  63  connecting the planar portion  51  to the first flap  55  at opposing positions intermediate the proximate end  56  and the distal end  57  thereof. The linking segments  63  provide stiffness and stability to the first flap  55  to maintain the configuration of the first flap  55  when the first reed  33  flexes towards and engages the first flap  55 . 
     The second flap  65  includes a proximate end  66  connected to and continuous with the planar portion  51  and a freely disposed distal end  67 . The second flap  65  further includes a contact surface  68  formed continuous with the first major surface  53  of the planar portion  51  with the contact surface  58  facing towards the second reed  34  of the double reed structure  30 . The second flap  65 , and more specifically the contact surface  68  thereof, is arranged at an incline relative to the plane of the planar portion  51  with the second flap  65  inclined away from the injection plate  22  and towards the valve body  80 . The incline includes an axial distance present between the contact surface  68  and the connecting portion  35  of the double reed structure  30  progressively increasing as the second flap  65  extends from the proximate end  66  to the distal end  67 . The contact surface  68  is configured to engage the second reed  34  when the second reed  34  is flexed or pivoted towards the contact surface  68  as a result of the pressure force applied thereto by the refrigerant passing through the valve assembly  20 . The contact surface  68  may include a substantially similar shape to the second reed  34  and may include a slightly larger size than the second reed  34  to ensure that the second reed  34  makes consistent contact with the contact surface  68  each time the second reed  34  is flexed towards the contact surface  68 . The incline of the contact surface  68  may be substantially constant, but may also include a slight curvature to account for any curvature present in the second reed  34  as a result of the flexing thereof. The incline of the contact surface  68  may be at an angle of about 3-5 degrees relative to the plane of the planar portion  51 , but other angles of inclination may be utilized while remaining within the scope of the present invention. 
     The inclined deviation of the second flap  65  from the planar portion  51  includes the formation of a peripheral opening  70  around at least a portion of the perimeter of the second flap  65 . The peripheral opening  70  is configured to allow for passage of the refrigerant through the valve gasket  50  when progressing towards the valve body  80 . In the provided embodiment, the peripheral opening  70  is subdivided into a pair of proximate openings  71  adjacent the proximate end  66  and a distal opening  72  extending around the distal end  67 , wherein the distal opening  72  is separated from the proximate openings  71  via a pair of opposing linking segments  73  connecting the planar portion  51  to the second flap  65  at opposing positions intermediate the proximate end  66  and the distal end  67  thereof. The linking segments  73  provide stiffness and stability to the second flap  65  to maintain the configuration of the second flap  65  when the second reed  34  flexes towards and engages the second flap  65 . 
     The valve gasket  50  includes four fastener openings  77  formed therethrough at positions exterior to the bead  52 . Each of the four fastener openings  77  is disposed in alignment with a corresponding one of the fastener openings  27  of the injection plate  22  and is configured to receive a corresponding one of the threaded fasteners  117  therethrough. The valve gasket  50  further includes a pair of locating openings  78  formed therethrough at positions interior to the bead  52 . Each of the pair of the locating openings  78  is disposed in alignment with a corresponding one of the locating openings  48  of the double reed structure  30  and is configured to receive a corresponding one of the locating features  118  therethrough. 
     The entirety of the valve gasket  50  (including the planar portion  51 , the bead  52 , the first flap  55 , and the second flap  65 ) is formed from a resiliently compressible material suitable for sealingly engaging each of the corresponding surfaces of the injection plate  22 , the double reed structure  30 , and the valve body  80  as described above. The valve gasket  50  may be formed (molded) from a polymeric material such as an elastomer, as desired. The use of the elastomeric material in forming the valve gasket  50  prevents repeated metal-to-metal contact with the reeds  33 ,  34  during operation of the scroll compressor  1 , which increases a durability of the double reed structure  30  due to the relative softness of the elastomeric material in comparison to a stiff metallic material. 
     The valve body  80  includes a periphery of the first major surface  81  thereof configured to engage a periphery of the second major surface  54  of the planar portion  51 . The periphery of the first major surface  81  is arranged perpendicular to the axial direction of the valve assembly  20 . A second major surface  82  of the valve body  80  formed opposite the first major surface  81  faces towards the outer face  16  of the fixed scroll  5 . The first major surface  81  includes a first indentation  85  ( FIG. 6 ) and a spaced apart second indentation  95  ( FIG. 7 ) formed therein with the indentations  85 ,  95  extending longitudinally in parallel to each other in a staggered configuration. 
     The first indentation  85  is disposed in alignment with the first flap  55  with respect to the axial direction of the valve assembly  20  with at least a portion of the inclined first flap  55  extending into the first indentation  85 . The first indentation  85  is defined by a surface  86  inclined at an angle relative to the plane of the periphery of the first major surface  81 . The surface  86  extends from a proximate end  87  disposed adjacent the proximate end  56  of the first flap  55  to a distal end  88  disposed adjacent the distal end  57  of the first flap  55 . An axial depth of the first indentation  85  increases as the surface  86  progresses from the proximate end  87  to the distal end  88  thereof to cause the distal end  88  to have a maximized depth towards the fixed scroll  5 . The angle of inclination of the surface  86  may substantially correspond to the angle of inclination of the first flap  55 , such as being inclined at about 3-5 degrees, but alternative configurations may be utilized without necessarily departing from the scope of the present invention. 
     The extension of the first flap  55  into the first indentation  85  divides the first indentation  85  into a first flow space  89  between the first flap  55  and the plane defined by the periphery of the first major surface  81  and a second flow space  91  between the first flap  55  and the inclined portion of the surface  86 . Any refrigerant present within the first flow space  89  is able to flow through the valve gasket  50  to the second flow space  91  by flowing through the peripheral opening  60  surrounding the first flap  55 . 
     The second major surface  82  of the valve body  80  includes a first post  83  projecting axially therefrom and towards the fixed scroll  5 . A first flow passageway  92  is formed through the valve body  80  and extends from the first indentation  85  to an axial end of the first post  83  engaging the fixed scroll  5  around a periphery of the first injection port  17 . The first flow passageway  92  provides fluid communication between the first indentation  85  and the first injection port  17  of the fixed scroll  5 . An O-ring or similar sealing element (not shown) may be disposed between an end portion of the first post  83  and the outer face  16  of the fixed scroll  5  or a surface defining the first injection port  17  to fluidly seal the joint therebetween. The first flow passageway  92  may extend from the distal end  88  of the surface  86  defining the first indentation  85  at a position offset from the distal end  57  of the first flap  55  with respect to a direction perpendicular to the axial direction of the valve assembly  20 . The offset may be present to prevent too great of a change of direction of the refrigerant when flowing from the distal end  57  of the first flap  55  towards the first flow passageway  92 . The first indentation  85  and the first flow passageway  92  accordingly cooperate to form a first flow path through the valve body  80  configured for fluid communication with the first injection port  17 . 
     The first flow passageway  92  is formed from a first segment  93  extending from the surface  86  of the first indentation  85  and a second segment  94  (shown in phantom lines in  FIG. 6 ) extending to the end of the first post  83 . The configuration of the first flow passageway  92  may be best understood by review of a second flow passageway  102  associated with the second indentation  95  as shown in  FIG. 7 , due to each of the flow paths  92 ,  102  having substantially identical configurations. The first segment  93  and the second segment  94  are each shown as having a substantially cylindrical shape for forming a substantially circular cross-sectional flow area through each of the segments  93 ,  94 , but alternative configurations may be utilized without necessarily departing from the scope of the present invention. The first segment  93  includes a first diameter that is greater than a second diameter of the second segment  94 , thus the first segment  93  includes a greater cross-sectional flow area than the second segment  94 . The first segment  93  having a larger cross-sectional area than the second segment  94  reduces a pressure drop experienced by the refrigerant when flowing through the first flow passageway  92  to minimize flow losses during operation of the valve assembly  20 . Additionally, the cross-sectional flow area through the first indentation  85  immediately upstream of the first flow passageway  92  is also greater than that of the first segment  93  thereof, thereby further ensuring the absence of the pressure drop and flow loss. 
     The first segment  93  and the second segment  94  may be disposed at an angle relative to each other. In the illustrated embodiment, the first segment  93  is inclined relative to the axial direction of the valve assembly  20  while the second segment  94  is axially aligned with the first injection port  17  and arranged parallel to the axial direction of the valve assembly  20 . 
     The second indentation  95  is disposed in alignment with the second flap  65  with respect to the axial direction of the valve assembly  20  with at least a portion of the inclined second flap  65  extending into the second indentation  95 . The second indentation  95  is defined by a surface  96  inclined at an angle relative to the plane of the periphery of the first major surface  81 . The surface  96  extends from a proximate end  97  disposed adjacent the proximate end  66  of the second flap  65  to a distal end  98  disposed adjacent the distal end  67  of the second flap  65 . An axial depth of the second indentation  95  increases as the surface  96  progresses from the proximate end  97  to the distal end  98  thereof to cause the distal end  98  to have a maximized depth towards the fixed scroll  5 . The angle of inclination of the surface  96  may substantially correspond to the angle of inclination of the second flap  65 , such as being inclined at about 3-5 degrees, but alternative configurations may be utilized without necessarily departing from the scope of the present invention. 
     The extension of the second flap  65  into the second indentation  95  divides the second indentation  95  into a first flow space  99  between the second flap  65  and the plane defined by the periphery of the first major surface  81  and a second flow space  101  between the second flap  65  and the inclined portion of the surface  96 . Any refrigerant present within the first flow space  99  is able to flow through the valve gasket  50  to the second flow space  101  by flowing through the peripheral opening  70  surrounding the second flap  65 . 
     The second major surface  82  of the valve body  80  includes a second post  84  projecting axially therefrom and towards the fixed scroll  5 . The second flow passageway  102  is formed through the valve body  80  and extends from the second indentation  95  to an axial end of the second post  84  engaging the fixed scroll  5  around a periphery of the second injection port  18 . The second flow passageway  102  provides fluid communication between the second indentation  95  and the second injection port  18  of the fixed scroll  5 . An O-ring or similar sealing element (not shown) may be disposed between the end portion of the second post  84  and the outer face  16  of the fixed scroll  5  or a surface of the second injection port  18  to fluidly seal the joint therebetween. The second flow passageway  102  may extend from the distal end  98  of the surface  96  defining the second indentation  95  at a position offset from the distal end  67  of the second flap  65  with respect to a direction perpendicular to the axial direction of the valve assembly  20 . The offset may be present to prevent too great of a change of direction of the refrigerant when flowing from the distal end  67  of the second flap  65  towards the second flow passageway  102 . The second indentation  95  and the second flow passageway  102  accordingly cooperate to form a second flow path through the valve body  80  configured for fluid communication with the second injection port  18 . 
     The second flow passageway  102  is formed from a first segment  103  extending from the surface  96  of the second indentation  95  and a second segment  104  extending to the end of the second post  84 . The first segment  103  and the second segment  104  are each shown as having a substantially cylindrical shape for forming a substantially circular cross-sectional flow area through each of the segments  103 ,  104 , but alternative configurations may be utilized without necessarily departing from the scope of the present invention. The first segment  103  includes a first diameter that is greater than a second diameter of the second segment  104 , thus the first segment  103  includes a greater cross-sectional flow area than the second segment  104 . The first segment  103  having a larger cross-sectional area than the second segment  104  reduces a pressure drop experienced by the refrigerant when flowing through the second flow passageway  102  to minimize flow losses during operation of the valve assembly  20 . Additionally, the cross-sectional flow area through the second indentation  95  immediately upstream of the second flow passageway  102  is also greater than that of the first segment  103  thereof, thereby further ensuring the absence of the pressure drop and flow loss. 
     The first segment  103  and the second segment  104  may be disposed at an angle relative to each other. In the illustrated embodiment, the first segment  103  is inclined relative to the axial direction of the valve assembly  20  while the second segment  104  is axially aligned with the second injection port  18  and arranged parallel to the axial direction of the valve assembly  20 . 
     The valve body  80  includes four fastener openings  107  formed therethrough about a periphery thereof with each of the four fastener openings  107  disposed in alignment with a corresponding one of the fastener openings  77  of the valve gasket  50  and configured to receive a corresponding one of the threaded fasteners  117  therethrough. The valve body  80  further includes a pair of locating openings  108  formed therethrough with each of the pair of the locating openings  108  disposed in alignment with a corresponding one of the locating openings  78  of the valve gasket  50  and configured to receive a corresponding one of the locating features  118  therethrough. 
     The valve body  80  is formed from a rigid material resistant to deformation when subjected to the pressure applied by the refrigerant passing through the valve assembly  20 . The valve body  80  may be formed from a metallic material such as aluminum, aluminum alloy, steel, or the like, as desired. 
     Operation of the valve assembly  20  is now described. Because the flow configuration of the refrigerant is substantially identical with respect to each of the partial refrigerant flows entering each of the injection ports  17 ,  18 , only the partial refrigerant flow passing from the first injection hole  25  to the first injection port  17  is described in detail hereinafter with the understanding that the corresponding and analogous components associated with the other partial refrigerant flow passing from the second injection hole  26  to the second injection port  18  operate in the same manner. 
     During operation of the scroll compressor  1 , at least a portion of the refrigerant discharged from the compression mechanism formed by the cooperating scrolls  5 ,  7  is returned back to the injection chamber  113  via the refrigerant return passage  112 . The end portion  39  of the first reed  33  is configured to normally extend across and cover the first injection hole  25  to prevent undesired flow of the returned refrigerant from the injection chamber  3  and towards the first injection port  17 . The compression mechanism of the scroll compressor  1  operates to cause the first injection port  17  to repeatedly experience a variable pressure of the refrigerant within the compression mechanism depending on the progression of each subsequent compression chamber  9  passing by the first injection port  17 . 
     When the variable pressure experienced by the first injection port  17  from the refrigerant originating from within the compression mechanism is relatively high, the end portion  39  of the first reed  33  is maintained against the surface of the injection plate  22  surrounding the first injection hole  25  to continue to prevent the passage of the refrigerant within the injection chamber  113  towards the first injection port  17 . However, when the variable pressure experienced by the first injection port  17  from the refrigerant originating from within the compression mechanism is relatively low, the pressure of the refrigerant within the injection chamber  113  eventually exceeds the relatively low pressure originating from the compression mechanism and a pressure differential is established across the opposing surfaces of the end portion  39  of the first reed  33 . When the force of the pressure of the refrigerant within the injection chamber  113  exceeds the combined force of the pressure of the refrigerant originating from the compression mechanism and a spring force generated by a resiliency of the first reed  33  at the pivot portion  38  thereof, the first reed  33  pivots about the axis defined by the pivot portion  38  and towards the valve body  80 . The pivoting of the first reed  33  causes the refrigerant within the injection chamber  113  to pass through the first injection hole  25  and around the now axially spaced end portion  39  of the first reed  33 . The first reed  33  may pivot until encountering the contact surface  58  of the first flap  55  of the valve gasket  50 , which provides a relatively soft stop limiting the rotation of the first reed  33 . 
     The refrigerant originating from the injection chamber  113  then proceeds through the open space formed by the first indentation  85  of the valve body  80  while passing through the valve gasket  50  via the peripheral opening  60  surrounding the first flap  55 . The refrigerant then flows towards and passes through the first flow passageway  92  and into the first injection port  17 . The refrigerant is then injected into the corresponding compression chamber  9  while having a higher pressure than the refrigerant already disposed within the compression chamber  9  and originating from one of the inlet openings  11  of the fixed scroll  5 , which allows for the compression capacity of the scroll compressor  1  to be increased by reintroducing higher pressure refrigerant into the compression mechanism at an intermediate position of the compression process. 
     The first reed  33  eventually resiliently springs back to the position blocking flow from the injection chamber  113  through the valve assembly  20  based on the cycling of the compression mechanism and the resulting pressure differential on the opposing sides of the first reed  33 . The valve assembly  20  accordingly acts a check valve for preventing a flow of the refrigerant in an undesired direction relative to the first reed  33 , which in turn prevents the refrigerant originating from the compression mechanism backflowing into the injection chamber  113  in an undesired flow direction. The described process is repeatedly performed as the pressure experienced by the first injection port  17  is varied with respect to each passing compression chamber  9  formed by the orbiting of the orbiting scroll  7  relative to the fixed scroll  5 . 
     The valve assembly  20  as shown and described offers numerous advantageous features. As is apparent from a review of  FIGS. 3-5 , a first half of the valve assembly  20  having the components associated with the partial flow towards the first injection port  17  and a second half of the valve assembly  20  having the components associated with the partial flow towards the second injection port  18  are substantially structurally identical with the second half rotated 180 degrees relative to the first half with respect to a central axis passing through the valve assembly  20 , wherein the central axis substantially corresponds to the position of the discharge opening  13  of the fixed scroll  5  and the position at which the refrigerant return passageway  112  intersects the injection chamber  113 . This staggered and 180 degree rotated relationship between the two partial flows results in a more even distribution of the refrigerant to each of the injection ports  17 ,  18  as each of the partial flows experiences substantially similar flow conditions and flow path lengths. The elongation of each of the injection holes  25 ,  26  allows for a greater pressure force to be applied to each of the reeds  33 ,  34  for selectively actuating the reeds  33 ,  34 . The unitary formation of the double reed structure  30  simplifies the manufacturing of the valve assembly  20 . The inclined flaps  55 ,  65  of the valve gasket  50  provide soft contact surfaces  58 ,  68  for preventing metal-to-metal contact with the reeds  33 ,  34  during repeated flexing of the reeds  33 ,  34 . This soft contact increases the durability of the reeds  33 ,  34  and prevents the generation of NVH that could be experienced within the passenger compartment of the vehicle. The inclined configuration of the flaps  55 ,  65  also prescribed the degree of flex experienced by each of the reeds  33 ,  34 , which further improves the durability of the reeds  33 ,  34  at the respective pivot portions  38 ,  42  thereof. The progressively decreasing flow area through each of the flows paths formed through the valve body  80  prevents an undesired pressure drop or flow loss for the refrigerant when flowing towards the respective injection ports  17 ,  18 . 
     Referring now to  FIGS. 8-12 , a valve assembly  220  according to another embodiment of the present invention is disclosed. The valve assembly  220  is similar to the valve assembly  20  is many respects, and includes an injection plate  222 , a double reed structure  230 , and valve body  280 , each of which may be formed from the same materials described as being suitable for use in forming the corresponding components of the valve assembly  20 . The components forming the valve assembly  220  include similarly positioned locating openings and fastener openings for positioning the valve assembly  220  between the fixed scroll  5  and the rear housing  110  as described with reference to the valve assembly  20 , hence further description of these features and a method of assembly of the valve assembly  220  are omitted herefrom. However, the valve assembly  220  differs from the valve assembly  20  in that a valve gasket (not shown) of the valve assembly  220  is used only to form a peripheral seal between the injection plate  222  and the valve body  280  for preventing the lateral escape of the refrigerant passing through the valve assembly  220 , and is not disposed between the double reed structure  230  and the valve body  280  for providing a contact surface for the double reed structure  230  to engage during a flexing thereof as described hereinabove. 
     The injection plate  222  includes a substantially planar first major surface  223  and an oppositely arranged and also substantially planar second major surface  224 . The injection plate  222  includes a first injection hole  225  and a spaced apart second injection hole  226  extending through the injection plate  222  with respect to the axial direction from the first major surface  223  to the second major surface  224  thereof, wherein each of the injections holes  225 ,  226  is positioned and shaped in similar fashion to the injections holes  25 ,  26  of the valve assembly  20 . 
     The double reed structure  230  is a thin and planar plate-like body including a first major surface  231  and an oppositely arranged second major surface  232 . The double reed structure  230  includes a first reed  233 , a second reed  234 , and a connecting portion  235 , with the reeds  233 ,  234  and the connecting portion  235  once again integrally formed as one monolithic structure. The first reed  233  includes an arm  237  extending longitudinally between a pivot portion  238  and an end portion  239  while the second reed  234  includes an arm  241  extending longitudinally between a pivot portion  242  and an end portion  243 . The reeds  233 ,  234  once again pivot about the corresponding pivot portions  238 ,  242  with the corresponding end portions  239 ,  243  configured to selectively cover each of the corresponding injection holes  225 ,  226 . The arms  237 ,  241  and the end portions  239 ,  243  include substantially similar shapes and configurations as the arms  37 ,  41  and the end portions  39 ,  43  of the double reed structure  30  of the valve assembly  20 . The connecting portion  235  differs from the connecting portion  35  of the valve assembly  20  in that the connecting portion  235  extends around a periphery of the double reed structure  230  when connecting the pivot portions  238 ,  242  rather than extending across a central portion of the double reed structure  230 . 
     The valve body  280  includes a first major surface  281  thereof configured to engage the connecting portion  235  of the double reed structure  230  and an oppositely arranged second major surface  282  configured to face towards the outer face  16  of the fixed scroll  5 . The first major surface  81  includes a first indentation  285  corresponding to the first reed  233  and a spaced apart second indentation  295  corresponding to the second reed  234 . The first indentation  285  is defined by a surface  286  inclined at an angle relative to the plane of the periphery of the first major surface  281  with an axial depth of the first indentation  285  increasing as the surface  286  progresses towards the end portion  239  of the first reed  233 . The second indentation  295  is defined by a surface  296  inclined at an angle relative to the plane of the periphery of the first major surface  281  with an axial depth of the second indentation  295  increasing as the surface  296  progresses towards the end portion  243  of the second reed  234 . 
     The second major surface  282  of the valve body  280  includes a first post  283  projecting axially therefrom and towards the fixed scroll  5 . A first flow passageway  292  is formed through the valve body  280  and extends from a deep end of the first indentation  285  to an axial end of the first post  283  engaging the fixed scroll  5  around a periphery of the first injection port  17 . The first flow passageway  292  is formed from a first segment  293  extending from the surface  286  of the first indentation  285  and a second segment  294  extending to the end of the first post  283 . The first segment  293  includes a first diameter that is greater than a second diameter of the second segment  294 , thus the first segment  293  includes a greater cross-sectional flow area than the second segment  294 . The first segment  293  and the second segment  294  may be disposed at an angle relative to each other. In the illustrated embodiment, the first segment  293  is inclined relative to the axial direction of the valve assembly  220  while the second segment  294  is axially aligned with the first injection port  17  and arranged parallel to the axial direction of the valve assembly  220 . 
     The second major surface  282  of the valve body  280  includes a second post  284  projecting axially therefrom and towards the fixed scroll  5 . A second flow passageway  302  is formed through the valve body  280  and extends from a deep end of the second indentation  295  to an axial end of the second post  284  engaging the fixed scroll  5  around a periphery of the second injection port  18 . The second flow passageway  302  is formed from a first segment  303  extending from the surface  296  of the second indentation  295  and a second segment  304  extending to the end of the second post  284 . The first segment  303  includes a first diameter that is greater than a second diameter of the second segment  304 , thus the first segment  303  includes a greater cross-sectional flow area than the second segment  304 . In contrast to the first flow passageway  292 , the second flow passageway  302  includes the first segment  303  and the second segment  304  arranged in parallel and axially aligned with the second injection port  18 . 
     The first major surface  281  of the valve body  280  includes a peripherally disposed gasket groove  290  formed therein configured to receive a gasket therein. As mentioned above, the gasket disposed between the valve body  280  and the injection plate  222  does not extend to a position for interacting with the operation of the double reed structure  230 . Instead, the double reed structure  230  is sandwiched between the planar portions of the first major surface  281  and the second major surface  224  of the injection plate  222 . 
     The valve assembly  220  operates in substantially the same manner as the valve assembly  20 . The reeds  233 ,  234  normally engage the injection plate  222  at positions covering the corresponding injection holes  225 ,  226  until a pressure originating from the injection chamber  113  overcomes a pressure present in the respective injection ports  17 ,  18  as well as the spring force formed by each of the reeds  233 ,  234 . The force imbalance causes each of the reeds  233 ,  234  to selectively flex away from the injection plate  222  to allow for fluid communication to occur between the injection chamber  113  and each of the respective indentations  285 ,  295 . Each of the reeds  233 ,  234  flexes towards the respective surfaces  286 ,  296  defining the respective indentations  285 ,  295  and refrigerant flows through the respective injection holes  225 ,  226 , the respective indentations  285 ,  295 , and the respective flow passageways  292 ,  302  to provide fluid communication between the injection chamber  113  and each of the respective injection ports  17 ,  18 . 
     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.