Abstract:
Disclosed in the present invention is a large capacity defrosting valve, comprising a valve body; the upper end of the valve body is connected to an upper end cover; the valve body is provided with a piston therein; the piston is connected to a valve core; the upper end of the valve core is connected to a tension spring; the upper end of the tension spring is connected to the lower end of the upper end cover; the lower end of the valve body is connected to a lower end cover; the valve body is provided with a first channel and a second channel thereon; the lower end cover is provided with a third channel thereon; the upper end cover is provided with a fourth channel thereon; a power cavity is formed between the piston and the upper end cover; and a buffer cavity is formed between the piston and the valve body. The present invention has no impact during operation, and has good stability, high reliability and long service lift, thus greatly improving the heating efficiency of an air-conditioner.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Patent Application No. PCT/CN2015/091146 with an international filing date of Sep. 29, 2015, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201410516153.1, filed Sep. 30, 2014. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a large capacity defrosting valve, and belongs to the technical field of air-conditioner defrosting. The defrosting valve is used to sectionally defrost an evaporator when an air-conditioner is heating. 
       BACKGROUND 
       [0003]    When an air-conditioner is heating, the evaporator will defrost, and too thick frost will reduce the heating efficiency. Therefore, the evaporator is required to be defrosted. The existing defrosting mode is using a four-way valve to change air flow direction to defrost the evaporator wholly. When in defrost, the condenser becomes an evaporator, and heating is forced to stop thus reducing the heating efficiency of the air-conditioner. 
       SUMMARY 
       [0004]    The present invention aims to overcome the deficiencies of the prior a and provide a large capacity defrosting valve having good structural stability, high reliability, long service life and no leakage danger, thus greatly improving the heating efficiency of an air-conditioner. 
         [0005]    The objective of the present invention is achieved by the following measures: a large capacity defrosting valve, comprising a valve body; the upper end of the valve body is connected to an upper end cover; the valve body is provided with a piston therein; the piston is connected to a valve core; the upper end of the valve core is connected to a tension spring; the upper end of the tension spring is connected to the lower end of the upper end cover; the lower end of the valve body is connected to a lower end cover; the valve body is provided with a first channel and a second channel thereon; the lower end cover is provided with a third channel thereon; the upper end cover is provided with a fourth channel thereon; a power cavity is formed between the piston and the upper end cover; and a buffer cavity is formed between the piston and the valve body. 
         [0006]    The valve core is provided with a small valve cover at the lower end, and a small valve core therein; the lower part of the small valve core is sleeved with a small spring for jacking up the small valve core; the lower end of the small spring is connected to the small valve cover; and the small valve cover is provided with a channel thereon. 
         [0007]    The piston is connected to the valve core via a connecting rod; and the connecting rod is connected to the tension spring. 
         [0008]    The piston is provided with a fifth channel thereon. 
         [0009]    The valve core is provided with a sixth channel, at the upper end. 
         [0010]    The fourth channel is connected to a forcibly open solenoid valve via a pipe; and the forcibly open solenoid valve is connected to the third channel via a pipe. 
         [0011]    The second channel is connected to a defrosting solenoid valve. 
         [0012]    A sealing gasket is disposed between the valve body and the lower end cover. 
         [0013]    Compared to the prior art, the present invention has the following positive effects: the present invention has small impact, good stability, long service life and no leakage danger, and can sectionally defrost an evaporator without stopping heating when in defrost, thus greatly improving the heating efficiency of an air-conditioner. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a structural schematic diagram of the first embodiment of the present invention; 
           [0015]      FIG. 2  is a structural schematic diagram when the valve in  FIG. 1  just starts to operate; 
           [0016]      FIG. 3  is a structural schematic diagram after the valve in  FIG. 1  completes an operation; 
           [0017]      FIG. 4  is a structural schematic diagram when the valve in  FIG. 1  is opened; 
           [0018]      FIG. 5  is a structural schematic diagram of the open state of the second embodiment (having no small valve assemblies) of the present invention; 
           [0019]      FIG. 6  is a structural schematic diagram of the closed state of the second embodiment (having no small valve assemblies) of the present invention; 
           [0020]      FIG. 7  is a structural schematic diagram of the open state of the third embodiment (the connecting rod and the valve core are integrated) of the present invention; 
           [0021]      FIG. 8  is a structural schematic diagram of the closed state of the third embodiment (the connecting rod and the valve core are integrated) of the present invention; 
           [0022]      FIG. 9  is a structural schematic diagram of the open state of the fourth embodiment (having no intermediate separator) of the present invention; 
           [0023]      FIG. 10  is a structural schematic diagram of the closed state of the fourth embodiment (having no intermediate separator) of the present invention; 
           [0024]      FIG. 11  is a structural schematic diagram of the open state of the fifth embodiment (the second channel  14  is disposed above) of the present invention; 
           [0025]      FIG. 12  is a structural schematic diagram of the closed state of the fifth embodiment (the second channel  14  is disposed above) of the present invention; 
           [0026]      FIG. 13  is a diagram showing the normal heating state of an air-conditioner in which the present invention is applied; 
           [0027]      FIG. 14  is a diagram showing the sectional defrosting state of an air-conditioner in which the present invention is applied; 
           [0028]      FIG. 15  is a structural schematic diagram of the sixth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    In order to enable the objective, characteristics and advantages of the present invention to be more obvious and understandable, the preferred embodiments of the present invention will be detailed hereafter in connection with the drawings. 
         [0030]    The preferred embodiments of the present invention are detailed in connection with the drawings as follows: 
       Embodiment 1 
       [0031]    a large capacity defrosting valve(see  FIG. 1-4 ), comprising a valve body  2 ; the upper end of the valve body  2  is connected to an upper end cover  1 ; the valve body  2  is provided with a piston  6  therein; the piston  6  is connected to a valve core  5  via a connecting rod  7 , and is locked by a locking pad  12 . 
         [0032]    The upper end of the connecting rod  7  is connected to a tension spring  4 ; the upper end of the tension spring  4  is connected to the lower end of the upper end cover  1 . The valve core  5  is provided with, a small valve cover  10  at the lower end, and a small valve core  8  therein; the lower part of the small valve core  8  is sleeved with a small spring  9  for jacking up the small valve core  8 ; the lower end of the small spring  9  is connected to the small valve cover  10 . The lower end of the valve body  2  is connected to a lower end cover  3 ; a sealing gasket  11  is disposed between the valve body  2  and the lower end cover  3 ; the valve body  2  is provided with a first channel  13  and a second channel  14  thereon; the lower end cover is provided with a third channel  15  thereon; the upper end cover  1  is provided with a fourth channel  16  thereon; the piston  6  is provided with a fifth channel  17  thereon; the valve core  5  is provided with a sixth channel  18  at the upper end; the small valve cover  10  is provided with a seventh channel  19  thereon. The valve body  2  is provided with an intermediate separator  20  thereon; a buffer cavity  21  is formed between the piston  6 , the valve body  2  and the intermediate separator  20 ; a power cavity  22  is formed between the piston  6  and the upper end cover  1 . The fourth channel  16  is connected to a forcibly open solenoid valve  24  via a pipe; and the forcibly open solenoid valve  24  is connected to the third channel  15  via a pipe. 
         [0033]    When in use, the first channel  13  is connected to an evaporator; the second channel  14  is connected to a high temperature and pressure air compressor for discharging air; and the third channel  15  is connected to a compressor for returning air. 
         [0034]    When in normal operation, the second channel  14  has no high temperature and pressure air therein; the piston  6  and the valve core  5  are pulled to the upper side via the connecting rod  7  under the effect of the tension spring  4 ; the first channel  13  is communicated with the third channel  15 ; and the fluid passes through the first channel  13 , and flows to the third channel  15 . The state at this time is as shown in  FIG. 1 . 
         [0035]    When the high temperature and pressure fluid of the second channel  14  arrives, the air flow flows to a small valve core cavity  23  via the sixth channel  18 ; and the small valve core  8  moves downwards under the effect of pressure, and is closed by integrating with the small valve cover  10 . 
         [0036]    The air flow is further throttled to the buffer cavity  21  via a gap between the piston  6  and the intermediate separator  20 ; the piston  6  goes upwards under stress to prevent the valve core  5  from moving downwards; after the air flow in the buffer cavity  21  is throttled to the power cavity  22  via the channel  17  and the gap between the piston  6  and the valve body  2 , the upper surface of the piston  6  is under stress, pushing the piston  6  to move downwards; but the piston  6  moves downwards slowly under the resistance effect of the buffer cavity  21  The moving state at this time is as shown in  FIG. 2 . 
         [0037]    When the valve core  5  moves and is integrated with a lower sealing gasket  11 , the third channel  15  is closed; the second channel  14  is communicated with the first channel  13 ; the high temperature and pressure air passes through the second channel  14 , flows to the first channel  13 , and enters the evaporator for defrosting. See  FIG. 3 . 
         [0038]    After the defrosting is completed, the high temperature and pressure air in the second channel  14  disappears; the pressure of the first channel  13  is slowly reduced; when the pressure is reduced to the response pressure of the small valve core  8 , the small spring  9  up-springs the small valve core  8 ; the sixth channel  18  and the seventh channel  19  are opened; the air in the first channel  13  is discharged via the sixth channel  18  and the seventh channel  19  to reduce the pressure; when the pressure is reduced to the response pressure of the valve core  5 , the valve core  5  is lifted up under the tensile force of the tension spring  4 ; the first channel  13  and the third channel  15  are opened; and the evaporator continues the heat absorption operation. The open state diagram of the small valve core is as shown in  FIG. 4 . 
         [0039]    At any time when the lower end of a big valve core  5  is closed, if the forcibly open solenoid valve  24  is opened, then the high pressure air in the power cavity  22  is discharged to the third channel  15  with a low pressure via the fourth channel  16  and the forcibly open solenoid valve  24 ; the piston  6  moves upwards under the upward pressure of the buffer cavity  21  and the tensile force of the tension spring  4 , and drives the valve core  5  to move upwards; in the process of upward moving, the communication between the second channel  14  and the first channel  13  is closed, and the connection between the first channel  13  and the third channel  15  is forcibly opened. 
       Embodiment 2 
       [0040]    a large capacity defrosting valve (see  FIG. 5-6 ), having basically the same structure and principle with that of embodiment 1; the differences thereof are: omitting the fifth channel  17  and small valve assemblies, namely having no small valve core  8 , small spring  9 , small valve cover  10 , the sixth channel  18  and the seventh channel  19 , but only having a single-stage differential pressure for relieving pressure. 
         [0041]    When the high temperature and pressure fluid of the second channel  14  arrives, the air flow is throttled to the buffer cavity  21  via a gap between the piston  6  and the intermediate separator  20 ; the piston  6  goes upwards under stress to prevent the valve core  5  from moving downwards; after the air flow in the buffer cavity  21  is throttled to the power cavity  22  via the gap between the piston  6  and the valve body  2 , the upper surface of the piston  6  is under stress, pushing the piston  6  to move downwards; but the piston  6  moves downwards slowly under the resistance effect of the buffer cavity  21 . When the valve core  5  moves and is integrated with the lower sealing gasket  11 , the third channel  15  is closed; the second channel  14  is communicated with the first channel  13 ; the high temperature and pressure air passes through the second channel  14 , flows to the first channel  13 , and enters the evaporator for defrosting. 
         [0042]    After the defrosting is completed, the high temperature and pressure air in the second channel  14  disappears; the pressure of the first channel  13  is slowly reduced; when the pressure is reduced to the response pressure of the valve core  5 , the valve core  5  is lifted up under the tensile force of the tension spring  4 ; the first channel  13  and the third channel  15  are opened; and the evaporator continues the heat absorption operation. 
         [0043]    At any time when the lower end of the big valve core  5  is closed, if the forcibly open solenoid valve  24  is opened, then the high pressure air in the power cavity  22  is discharged to the third channel  15  with a low pressure via the fourth channel  16  and the forcibly open solenoid valve  24 ; the piston  6  moves upwards under the upward pressure of the buffer cavity  21  and the tensile force of the tension spring  4 , and drives the valve core  5  to move upwards; in the process of upward moving, the communication between the second channel  14  and the first channel  13  is closed, and the connection between the first channel  13  and the third channel  15  is opened. 
       Embodiment 3 
       [0044]    a large capacity defrosting valve (see  FIG. 7-8 ), having basically the same structure and principle with that of embodiment 1; the differences thereof are: the connecting rod  7  and the valve core  5  are integrated, and the locking pad  12  is omitted, thus reducing the number of the components. 
       Embodiment 4 
       [0045]    a large capacity defrosting valve (see  FIG. 9-10 ), having basically the same structure and principle with that of embodiment 1; the differences thereof are: omitting the intermediate separator  20 , reducing the buffer effect. The present embodiment can be used in special occasions having no requirement for vibration. 
         [0046]    When the high temperature and pressure fluid of the second channel  14  arrives, the air flow is throttled to the buffer cavity  21  via a gap between the piston  6  and the valve body  2 ; since no intermediate separator exists (the lower surface of the piston  6  and the upper surface of the valve core  5  are under the stress in opposite directions), the move resistance effect disappears. After the air flow in the buffer cavity  21  is throttled to the power cavity  22  via the channel  17 , the upper surface of the piston  6  is under stress, pushing the piston  6  to move downwards. When the valve core  5  moves and is integrated with the lower sealing gasket  11 , the third channel  15  is closed; the second channel  14  is communicated with the first channel  13 ; the high temperature and pressure air passes through the second channel  14 , flows to the first channel  13 , and enters the evaporator for defrosting. 
         [0047]    After the defrosting is completed, the high temperature and pressure air in the second channel  14  disappears; the pressure of the first channel  13  is slowly reduced; when the pressure is reduced to the response pressure of the valve core  5 , the valve core  5  is lifted up under the tensile force of the tension spring  4 ; the first channel  13  and the third channel  15  are opened; and the evaporator continues the heat absorption operation. 
         [0048]    At any time when the lower end of the big valve core  5  is closed, if the forcibly open solenoid valve  24  is opened, then the high pressure air in the power cavity  22  is discharged to the third channel  15  with a low pressure via the fourth channel  16  and the forcibly open solenoid valve  24 ; the piston  6  moves upwards under the effect of the tension spring  4 , and drives the valve core  5  to move upwards; in the process of upward moving, the communication between the second channel  14  and the first channel  13  is closed, and the connection between the first channel  13  and the third channel  15  is opened. The present solution reduces the processing difficulty and cost, and is suitable for the occasions having low requirement for impact. 
       Embodiment 5 
       [0049]    a large capacity defrosting valve (see  FIG. 11-12 ), having basically the same structure and principle with that of embodiment 2; the differences thereof are: the connecting rod  7  and the valve core  5  are integrated; the locking pad  12  is omitted; furthermore, the second channel  14 , the forcibly open solenoid valve  24 , and the pipe connected to the third channel  15  are omitted. When in use, the fourth channel  16  is connected to the air discharge pipe of the high temperature and pressure air compressor; the fourth channel  16  plays the role of the second channel  14  in embodiment 1. The fifth channel  17  on the piston  6  is widened. The present solution has a simpler structure, saves cost, can be installed at a specific place, and is suitable for the occasions having no requirement for forcible opening. 
         [0050]    When the high temperature and pressure fluid of the fourth channel  16  arrives, the upper surface of the piston  6  is under a downward stress under the effect of the high temperature and pressure air coming from the fourth channel  16 , pushing the piston  6  and the valve core  5  to move downwards. The high temperature and pressure fluid of the fourth channel  16  also flows to the buffer cavity  21  via the channel  17 ; the lower surface of the piston  6  is under an upward stress, preventing the valve core  5  from moving downwards, thus, the piston  6  plays a buffer effect. When the valve core  5  moves and is integrated with the lower sealing gasket  11 , the third channel  15  is closed; the fourth channel  16  is communicated with the first channel  13  via the widened channel  17 ; the high temperature and pressure air passes through the first channel  13 , and enters the evaporator for defrosting. 
         [0051]    After the defrosting is completed, the high temperature and pressure air in the fourth channel  16  disappears; the pressure of the first channel  13  is slowly reduced; when the pressure is reduced to the response pressure of the valve core  5 , the valve core  5  is lifted up under the tensile force of the tension spring  4 ; the first channel  13  and the third channel  15  are opened; and the evaporator continues the heat absorption operation. 
         [0052]    If a double-stage differential pressure is required to open the defrosting valve, then the small valve core assemblies such as the small valve core  8 , the small spring  9 , the small valve cover  10 , the sixth channel  18  and the seventh channel  19  can be added according to embodiment 1. 
       Embodiment 6 
       [0053]    a large capacity defrosting valve (see  FIG. 15 ), having basically the same structure and principle with that of embodiment 1; the differences thereof are: the second channel  14  is connected, to a defrosting solenoid valve  25 , such that the present defrosting valve becomes a valve group integrated with the forcibly open solenoid valve  24  and the defrosting solenoid valve  25 , thus having a compact structure and low cost. 
         [0054]    The schematic diagram of the defrosting valve of the invention when the air-conditioner is heating is as shown in  FIG. 13 . And the schematic diagram of the defrosting valve of the invention when performing sectional defrosting is as shown in  FIG. 14 . 
         [0055]    When the air-conditioner is heating, as shown in  FIG. 13 , the valve group defrosting solenoid valve  25  does not operate; the second channel  14  has no high temperature and pressure air therein, thus the defrosting valve does not operate; a refrigerant from the condenser  28  enters the evaporator  30  via an expansion valve  29  for evaporating and absorbing heat, then flows out of the evaporator  30 , and flows back to the compressor  27  via the first channel  13  of the defrosting valve, the third channel  15  of the defrosting valve, and the four-way valve  26 . 
         [0056]    When the evaporator of an air-conditioner is frosted and required to be defrosted, as shown in  FIG. 14 , one of the defrosting solenoid valve  25  is opened; the high temperature and pressure air coming from the compressor  27  enters the second channel  14  of the defrosting valve; the piston  6  in the defrosting valve drives the valve core  5  to move, until the third channel  15  is closed, and the second channel  14  is communicated with the, first channel  13 ; the high temperature and pressure air passes through the channels  25 - 1  and  25 - 2  of the defrosting solenoid valve  25 , then the second channel  14  and the first channel  13  of the defrosting valve, and finally arrives at the evaporator  30  to heat and defrost the evaporator  30 . After the defrosting is completed, the defrosting solenoid valve  25  is closed; the high temperature and pressure air in the second channel  14  disappears; the pressure of the evaporator  30  is reduced; when the pressure is reduced to a certain value, the small valve core  8  is separated from the small valve cover  10  under the effect of the small spring  9 ; the refrigerant relieves pressure via the sixth channel  18  and the seventh channel  19 . When the pressure is further reduced, under the effect of the tension spring  4 , the piston  6  drives the valve core  5  to move to the original position; the second channel  14  is closed; the first channel  13  is communicated with the third channel  15 ; and the evaporator  30  continues to operate. 
         [0057]    During the period the defrosting valve loses the third channel  15 , if the defrosting valve is required to be forcibly opened, then the forcibly open solenoid valve  24  operates; the high pressure air at the upper end of the piston  6  is discharged into the third channel  15  via the forcibly open solenoid valve  24 ; the pressure of the piston  6  disappears; under the effect of the tension spring  4 , the piston  6  and the valve core  5  move to the original positions; the second channel  14  is forcibly closed; and the connection between the first channel  13  and the third channel  15  is opened. 
         [0058]    If another evaporator is required to be defrosted, then nothing requires but to open the defrosting solenoid valve of another defrosting valve. 
         [0059]    The embodiments above are only the preferred embodiments of the present invention, but not intended to restrict the scope of the present invention. Under the premise without deviating from the design spirit of the present invention, any variations and improvements made to the technical solution of the present invention by an ordinary person skilled in the art, shall be all concluded in the protection scope defined by the claims of the present invention.