Patent Publication Number: US-2023141369-A1

Title: Pipe connection assembly of heat exchanger

Description:
TECHNICAL FIELD 
     The present invention relates to a pipe connection assembly of a heat exchanger, and more particularly, to an assembly connecting an inlet and an outlet formed on a header tank of a heat exchanger and a pipe to each other. 
     BACKGROUND ART 
     In general, heat exchangers are devices installed on specific flow paths so as to perform heat exchange in such a way that a heat exchange medium circulating inside absorbs heat from the outside or radiates heat to the outside. Such heat exchangers are variously manufactured depending on use purposes, like a condenser and an evaporator using a refrigerant as a heat exchange medium, a radiator and a heater core using a coolant as a heat exchange medium, an oil cooler using oil used in an engine, a transmission, and the like, as a heat exchange medium, or the like. 
     In this case, the heat exchanger generally has a form in which a header tank is coupled to both ends of a plurality of tubes through which heat transfer is performed between an internal fluid and an external fluid. In addition, a manifold including an inlet and an outlet through which a heat exchange medium flows is configured in the header tank, and a pipe is fixedly coupled to the manifold, such that a heat exchange medium is introduced from another engine or a heat exchange medium of which heat transfer is performed is discharged to another engine. An evaporator, which is a type of such a heat exchanger, is disclosed in Korean Patent Laid-Open Publication No. 10-2016-0026750 (entitled “Evaporator” and hereinafter referred to as “Related Art Document 1”). 
     Referring to  FIG.  1   , an evaporator  1  according to Related Art Document 1 may be configured to include a first header tank  2   a,  a second header tank  2   b,  an inlet pipe  3 , an outlet pipe  4  and a core part  5 . In this case, the evaporator  1  may include a function of cooling air introduced by a blower by heat exchange in a process in which a liquid heat exchange medium is changed to a gaseous state and supplying the cooled air into the interior. In addition, the heat exchange medium may be introduced into the inlet pipe  3  and discharged from the outlet pipe  4 , and may flow on the first header tank  2   a  or the second header tank  2   b  partitioned into two rows by an internal partition wall. Accordingly, Related Art Document 1 has provided the evaporator  1  having a plurality of pass flows by disposing a manifold including the inlet pipe  3  and the outlet pipe  4  in any one of the first header tank  2   a  or the second header tank  2   b.    
     Next, referring to  FIG.  2   , in the related art, a welding process has been performed through a pipe connection assembly including a welding ring  7   c  so as to connect the manifold  7   a  including the inlet pipe or the outlet pipe as described above and a pipe  7   b  of which a flow path is connected to other components in a vehicle to each other. Here, in the welding process according to the related art, a welding ring  7   c  was disposed on an outer surface of the pipe  7   b,  and when the pipe  7   b  is partially inserted into the manifold  7   a,  the pipe  7   b  and the manifold  7   a  have been fixed to each other by applying heat to the welding ring  7   c  through a welding torch or the like. However, in the related art, a problem that the molten welding ring  7   c  overflows to the outside of the manifold  7   a  has occurred due to a narrow space between the outer surface of the pipe  7   b  and an opening of the manifold  7   a.  Accordingly, there was a disadvantage that the heat exchanger is contaminated due to the residual welding ring  7   c  disposed on the outside of the manifold  7   a  and the pipe  7   b.    
     Currently, in order to solve the problems as described above, technologies such as Korean Patent Laid-Open Publication No. 10-2016-0087940 (entitled “Welded Construction of Inlet and Outlet Pipes of Heat Exchanger” and hereinafter referred to as “Related Art Document 2”) have been disclosed. As illustrated in  FIG.  3   , in Related Art Document 2, an opening of a manifold  8   a  is formed to have a greater diameter than a welding ring  8   c,  such that a portion of the welding ring  8   c  is inserted into the opening of the manifold  8   a.  However, since a welding torch used in a welding process first heats an outer portion of the welding ring  8   c,  there is a problem that a portion of the welding ring  8   c  introduced into the opening of the manifold  8   a  is relatively slowly molten, such that the first molten outer portion of the welding ring  8   c  overflows to the outside along a distal end portion of the opening. 
     DISCLOSURE 
     Technical Problem 
     An object of the present invention is to provide a pipe connection assembly of a heat exchanger in which a space between an inner surface of one end of a manifold and an outer surface of a pipe may be secured so that a molten welding ring is accommodated and the welding ring may be exposed to the outside in a welding process. 
     Technical Solution 
     In one general aspect, a pipe connection assembly of a heat exchanger connecting a header tank and a pipe of the heat exchanger to each other includes: a manifold having one end connected to the pipe and the other end connected to an inner portion of the header tank so that a heat exchange medium flows; and a welding ring disposed at one end of the manifold so that the manifold and the pipe are fixedly coupled to each other, wherein the welding ring is disposed on one end surface of the manifold, and a space is formed between an inner surface of one end of the manifold and an outer surface of the inserted pipe, such that the molten welding ring is accommodated. 
     In addition, the manifold may have a protrusion part protruding toward a hollow inner portion and disposed on an inner surface of one end. 
     In addition, one end of the manifold may include a first body and a second body connected to one end of the first body and having an inner diameter greater than that of the first body, and the protrusion part may be disposed on the second body. 
     In addition, the welding ring may be disposed to be seated on the protrusion part. 
     In addition, in the manifold, an inner diameter of the second body may be formed to be smaller than an outer diameter of the welding ring, such that a portion of the welding ring is seated on the second body. 
     In addition, in the manifold, a length difference between the outer diameter of the welding ring and the inner diameter of the second body may be formed to be smaller than a clearance between an inner surface of the welding ring and the outer surface of the pipe. 
     In addition, the inner diameter of the second body may be formed to be greater than the outer diameter of the welding ring, such that a thickness of inner and outer sides of the welding ring is smaller than a clearance between an inner surface of the second body and the outer surface of the pipe. 
     In addition, the second body may have an inner diameter that becomes narrower toward the first body. 
     In addition, a portion of the pipe may be depressed inward so that a clearance between an inner surface of the second body and the outer surface of the pipe increases. 
     In addition, the number of protrusion parts may be plural, and the plurality of protrusion parts may be disposed to be spaced apart from each other along an inner circumferential surface of the second body. 
     In addition, the welding ring may have a projection part protruding outward and disposed on an outer surface thereof. 
     In addition, an outer diameter of the projection part may be formed to be greater than an inner diameter of one end side of the manifold, such that the welding ring is disposed on one end surface of the manifold. 
     In addition, the number of projection parts may be plural, and the plurality of projection parts may be disposed to be spaced apart from each other along an outer circumferential surface of the welding ring. 
     In another general aspect, a heat exchanger includes: a pair of header tanks disposed to be spaced apart from each other; a core part including a plurality of tubes having both ends coupled to the pair of header tanks, respectively, and disposed to be spaced apart from each other in both side directions, and a plurality of fins interposed between the plurality of tubes; and a pipe connection assembly coupled to one or more of the header tanks among the pair of header tanks, wherein the heat exchange medium flowing inside the header tank is introduced or discharged through the pipe connection assembly. 
     Advantageous Effects 
     In the pipe connection assembly of a heat exchanger according to the present invention having the configuration described above, a space is formed in a cup shape at an end portion of the manifold, such that a molten welding ring may be accommodated, and the welding ring may be prevented from being introduced into the space before a welding process. Accordingly, the present invention has not only an advantage of preventing welding by-products of the welding ring from flowing down to the outside of a manifold, but also an advantage of solving a problem such as a welding defect at the time of performing welding using a torch. 
     In addition, the present invention may allow a molten welding ring to be properly introduced into the space when heat is applied from the outside to the welding ring, according to settings of diameters (or radii) relationship between components of the pipe connection assembly of a heat exchanger. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view of an evaporator according to the related art. 
         FIGS.  2  and  3    are cross-sectional views of a pipe connection assembly according to the related art. 
         FIG.  4    is a perspective view of a heat exchanger according to a first embodiment of the present invention. 
         FIG.  5    is an exploded perspective view of a pipe connection assembly according to a first embodiment of the present invention. 
         FIG.  6    is a perspective view and an enlarged view of a main part of a manifold according to a first embodiment of the present invention. 
         FIGS.  7 A and  7 B  are views illustrating an assembling process of the pipe connection assembly according to a first embodiment of the present invention. 
         FIGS.  8 A,  8 B and  9    are cross-sectional views of the pipe connection assembly according to a first embodiment of the present invention. 
         FIG.  10    is a side cross-sectional view of a pipe connection assembly according to a second embodiment of the present invention. 
         FIGS.  11 A and  11 B  are views illustrating an assembling process of a pipe connection assembly according to a third embodiment of the present invention. 
         FIG.  12    is a plan cross-sectional view of the pipe connection assembly according to a third embodiment of the present invention. 
         FIG.  13    is an exploded perspective view of a pipe connection assembly according to a fourth embodiment of the present invention. 
         FIG.  14    is a plan cross-sectional view of the pipe connection assembly according to a fourth embodiment of the present invention. 
     
    
    
     BEST MODE 
     Hereinafter, a pipe connection assembly of a heat exchanger according to various embodiments of the present invention having the configuration as described above will be described in detail with reference to the accompanying drawings. 
     First Embodiment 
       FIGS.  4  and  5    illustrate a pipe connection assembly of a heat exchanger according to a first embodiment of the present invention, wherein  FIG.  4    is a perspective view of the heat exchanger, and  FIG.  5    is an exploded perspective view of the pipe connection assembly. 
     Referring to  FIG.  4   , the heat exchanger according to the present invention may include a manifold connection part  10 , header tanks  20 , and a core part  30 . In this case, the manifold connection part  10  may have a heat exchange medium introduced thereinto (F in ) and discharged therefrom (F out ), and may be fixedly coupled onto the header tank  20 . In addition, the header tanks  20  may be formed as a pair and be disposed to be spaced apart from each other in a height direction, and both ends of tubes  31  of the core part  30  in the height direction may be coupled to the pair of header tanks  20 , respectively. In addition, the manifold connection part  10  may include an inlet through which the heat exchange medium is introduced (F in ) and an outlet through which the heat exchange medium is discharged (F out ), and the inlet and outlet may be configured in various structures such as a structure in which they are both coupled to one header tank  20  or are coupled to the pair of header tank  20 , respectively, or a plurality of inlets and outlets are configured and coupled to the header tanks  20 . In addition, the core part  30  may include a plurality of tubes  31  disposed to be spaced apart from each other in a length direction and further include fins  32  interposed between the plurality of the tubes  31 . Here, since the heat exchanger according to the present invention may be formed as an evaporator, the heat exchange medium may flow inside the manifold connection part  10 , the header tanks  20 , and the tubes  31 , and air introduced by a blower may flow to the fins  32 . Therefore, the air may be cooled and supplied to the interior of a vehicle while the flowing heat exchange medium is evaporated. In addition, although not illustrated, a partition wall partitioning the interior into two or more rows, a baffle implementing a plurality of pass flows, or the like, may be further included in the header tank  20  according to the present invention. 
     The heat exchange medium will be described in more detail through a structure between the above components. When the heat exchange medium is introduced into the inlet of the manifold connection part  10 , the heat exchange medium may be distributed to the plurality of tubes  31  through the header tank  20 , and heat-exchanged with a fluid flowing outside the tube  31 . In addition, the heat exchange medium may flow along paths constituted by the header tank  20  and the tubes  31 , and the heat exchange medium that is heat-exchanged may be discharged through the outlet of the manifold connection part  10 . Here, the inlet and the outlet of the manifold connection part  10  may be connected to pipelines to be configured so that the heat exchange medium is introduced from another engine or discharged to another engine. 
     Referring to  FIG.  5   , the manifold connection part  10  may include one or more manifolds  100 , and the manifold  100  may be formed as an inlet  110  or an outlet  120 . In addition, a welding ring  300  may be disposed between the manifold  100  and a pipe  200  so that the manifold  100  and the pipe  200  may be fixedly coupled to each other. In this case, the welding ring  300  may be molten through a welding process to fixedly couple the manifold  100  and the pipe  200 . Hereinafter, the pipe connection assembly according to the present invention to be described may include a structure between the manifold  100  and the pipe  200  described above, and an end portion of the manifold  100  connected to the pipe  200  will be defined as one end and a direction in which the manifold  100  is connected to the header tank  20  will be defined as the other end direction. In this case, the manifold  100  may be connected to the header tank  20  through a separate housing of the manifold connection part  10  as illustrated or may be installed to be directly connected to the header tank  20  although not illustrated, and an illustrated structure is merely an example for more clearly describing the present invention, but the present invention is not limited thereto. 
       FIG.  6   ,  FIGS.  7 A to  7 B  illustrate the pipe connection assembly of a heat exchanger according to a first embodiment of the present invention, wherein  FIG.  6    is a perspective view and an enlarged view of a main part of a manifold, and  FIGS.  7 A and  7 B  we views illustrating an assembling process of the pipe connection assembly. 
     Referring to  FIG.  6   , the manifold  100  according to the present invention may be opened on one side, and hereinafter, in order to more clearly describe the present invention, a side on which the manifold  100  is opened will be defined as an upper side D 11 , an opposite direction to the upper side will be defined as a lower side D 12 , commonly as a vertical direction D 1 . In addition, the manifold  100  may have a body extending so that an inner portion thereof is hollow on the basis of a front and rear (D 2 ) and left and right (D 3 ) plane perpendicular to the vertical direction D 1 , and may extend in a shape such as a circular shape or a polygonal shape according to a form of the manifold  100 . In this case, on the basis of the front and rear and left and right plane, a direction toward a center point of the hollow will be defined as an inner side, and an opposite direction to the inner side will be defined as an outer side. In addition, as the body having a predetermined thickness extends, a diameter of an outer surface of the body will be defined as an outer diameter, a diameter of an inner surface of the body will be defined as an inner diameter, a distance from the center of the hollow to the outer surface will be referred to as an outer radius, and a distance from the center of the hollow to the inner surface will be referred to as an inner radius. In addition, in consideration of a case where the front and rear and left and right plane of the body has an irregular or polygonal shape, the outer diameter and inner diameter will be defined as two times the outer radius and two times the inner radius, respectively. 
     The manifold  100  may include a first body  101  and a second body  102 , and a hollow part  100   a  penetrating in the vertical direction may be hollow in the manifold  100 . In this case, the first body  101  may be a body extending vertically, and the second body  102  may be connected to an upper end of the first body  101  and extend upward. Here, an inner diameter of the second body  102  may be formed to be greater than an inner diameter of the first body  101 , and the second body  102  may have an inner diameter formed as a 1-1-th radius M 0 . In addition, the second body  102  may include an extension member  102   a  having the 1-1-th radius M 0  and a protrusion part  102   b  having a shape in which it protrudes toward the hollow part  100   a  on the extension member  102   a.  In this case, an inner end portion of the protrusion part  102   b  may have a 1-2-th radius M 1 , which may be formed to be smaller than the 1-1-th radius M 0 . Here, the number of protrusion parts  102   b  may be plural, the plurality of protrusion parts  102   b  may be formed and disposed to be spaced apart from each other along an inner circumferential surface of the second body  102 , and some of the plurality of protrusion parts  102   b  may be disposed in directions symmetrical to each other with respect to the center of the hollow part  100   a.    
     Referring to  FIGS.  7 A and  7 B  together, in a welding process using the pipe connection assembly according to the present invention, the welding ring  300  may be disposed on an upper end surface of the manifold  100  before welding, and the pipe  200  may be introduced into the hollow part  100   a  of the manifold  100  in a state in which the welding ring  300  is disposed. In this case, as described above, in the second body  102  of the manifold  100 , a space may be formed as the extension member  102   a  is disposed at the uppermost end and an inner surface is spaced apart from an outer surface of the pipe  200 , such that a space may be formed. Here, when the welding ring  300  is molten, the welding ring  300  may be introduced into the space. In addition, the protrusion part  102   b  of the second body  102  may prevent the welding ring  300  from being introduced into the space to support the welding ring  300  to be exposed to the outside before the welding. 
       FIGS.  8 A,  8 B and  9    illustrate the pipe connection assembly of a heat exchanger according to a first embodiment of the present invention, wherein  FIGS.  8 A,  8 B and  9    are side cross-sectional views of the pipe connection assembly. In this case,  FIGS.  8 A and  9    are side cross-sectional views taking along the extension member of one end of the manifold, and  FIG.  8 B  is a side cross-sectional view cut taken along the protrusion part of one end of the manifold. 
     Referring to  FIGS.  8 A and  8 B , the pipe  200  may be formed so that a diameter  2 Y of an outer surface thereof has a second radius Y, and the welding ring  300  may be formed so that a diameter  2 R of an outer surface and a diameter  2 R 0  of an inner surface thereof have a third radius R and a 3-1-th radius R 0 , respectively. In this case, as described above, inner surfaces of the extension member  102   a  and the protrusion part  102   b  of the second body  102  may be formed to have the 1-1-th radius M 0  and the 1-2-th radius M 1 , respectively, the respective radii may have lengths formed according to the following Relational Equation 1. 
       O&lt;Y≤R 0 &lt;M 1 &lt;M 0 &lt;R  [Relational Equation 1]
 
     That is, since the 1-1-th radius Mo and the 1-2-th radius M 1  of the second body  102  are formed to be smaller than the third radius R of the outer surface of the welding ring  300 , a portion of a lower surface of the welding ring  300  may be seated on the extension member  102   a  of the second body  102 , and the other portion of the lower surface of the welding ring  300  may be seated on the protrusion part  102   b  of the second body  102 . In addition, since the inner surface of the second body  102  and the outer surface of the pipe  200  are spaced apart from each other by a predetermined distance, an empty space is formed. Therefore, when the welding ring  300  is molten, the welding ring  300  may be introduced into the space. In this case, the inner diameter of the first body  100  may be formed to correspond to or different from the outer diameter of the pipe  200 , and when the inner diameter of the first body  100  corresponds to the outer diameter of the pipe  200 , the first body  100  and the pipe  200  may be coupled to each other so as to be tightly engaged with each other. 
     Alternatively, the above-described second body  102 , the pipe  200  and the welding ring  300  may be formed to have lengths according to the following Relational Equation (2). 
       O&lt;Y≤R 0 &lt;M 1 &lt;R&lt;M 0   [Relational Equation 2]
 
     This means that the inner diameter of the extension member  102   a  of the second body  102  is formed to be greater than the outer diameter of the welding ring  300  and the inner diameter of the protrusion part  102   b  of the second body  102  is formed to be smaller than the outer diameter of the welding ring  300 , and the welding ring  300  may be prevented from being introduced into the empty space before welding through the protrusion part  102 . 
     Referring to  FIG.  9   , a clearance (R 0 −Y) may be formed between an inner diameter of the welding ring  300  and the outer diameter of the pipe  200  in consideration of assemblability. In addition, as described above, the inner diameter of the extension member  102   a  may be formed to be greater than the outer diameter of the welding ring  300 , and a length difference (R−M 0 ) between the inner diameter of the extension member  102   a  and the outer diameter of the welding ring  300  may be formed to be the same as or different from the clearance (R 0 −Y). As an example, the clearance and the length difference (R−M 0 ) may be formed through the following Relational Equation (3). 
         R−M   0   &lt;R   0   −Y   [Relational Equation 3]
 
     In a case where the clearance and the length difference (R−M 0 ) are formed as in Relational Equation (3), when the welding ring  300  is biased toward one side, the welding ring  300  may be introduced into the space between the inner surface of the second body  102  and the outer surface of the pipe  200 , but the insertion of the welding ring  300  may be limited through the protrusion part  102   b  of the second body  102  described above. 
     Second Embodiment 
       FIG.  10    illustrates a pipe connection assembly of a heat exchanger according to a second embodiment of the present invention, and  FIG.  10    is a side cross-sectional view of the pipe connection assembly. 
     Referring to  FIG.  10   , the pipe  200  of the pipe connection assembly according to the present invention may be formed so that an outer surface of a lower end thereof is depressed inward. In this case, the pipe  200  may include a first pipe body  210  extending in the vertical direction so that an outer diameter thereof has a second radius Y and a second pipe body  220  connected to a lower end of the first pipe body  210  and having an outer diameter formed to have a 2-1-th radius Y 1 , as described above. In this case, the 2-1-th radius Y 1  is formed to have a length smaller than the second radius Y, and thus, the second pipe body  220  may be configured in a shape in which it is depressed inward. In this case, the term “inward” may be a hollow inward direction of the pipe  200 , and the second radius Y and the 2-1-th radius Y 1  are radii based the center of a hollow inner portion of the pipe  200 . 
     In addition, the pipe  200  may further include a third pipe body  230  connected to a lower end of the second pipe body  220 . In this case, the third pipe body  230  may have an outer diameter formed as a 2-2-th radius Y 2 , and the 2-2-th radius Y 2  may be formed to be grater than the 2-1-th radius Y 1 . In addition, the 2-2-th radius Y 2  may be formed as a length that is the same as or different from as the second radius Y. 
     In addition, the manifold  100  may further include a third body  103  extending downward of the first body  101 . In this case, an inner diameter of the third body  103  is formed to be smaller than the inner diameter of the first body  101  and the outer diameter of the lower end of the pipe  200 , and thus, an insertion depth of the pipe  200  may be limited. 
     Third Embodiment 
       FIGS.  11 A,  11 B and  12    illustrate a pipe connection assembly of a heat exchanger according to a third embodiment of the present invention, wherein  FIGS.  11 A and  11 B  are views illustrating an assembling process of the pipe connection assembly and  FIG.  12    is a plan cross-sectional view of the pipe connection assembly. 
     Referring to  FIGS.  11 A and  11 B , the welding ring  300  may be disposed on a point where the manifold  100  and the pipe  200  are in contact with each other. In more detail, when it is defined that one end of the manifold  100  is connected to the pipe  200  as illustrated in  FIG.  6    and the other end of the manifold  100  is connected to the header tank as described above, the welding ring  300  may be disposed on one end side of the manifold  100 , as illustrated in  FIG.  11 A . In addition, a hollow may be formed in each of one end of the manifold  100  and the welding ring  300 , and as illustrated in  FIG.  11 B , the pipe  200  may be inserted into the hollow. Next, in the present invention, when the pipe  200  is inserted into the hollow of the manifold  100 , the welding ring  300  is molten through a welding torch or the like, such that the manifold  100  and the pipe  200  may be welded and coupled to each other. In this case, as an embodiment of the welding process, one end of the manifold  100  is disposed to face an upward direction, and the welding ring  300  may be formed to be seated on an upper side of one end of the manifold  100 . In addition, the welding ring  300  may be molten to be accommodated while permeating into a gap between the outer surface of the pipe  200  and the inner surface of the manifold  100 . Here, the present invention may be characterized in that a projection part  310  protruding outward is formed on the outer surface of the welding ring  300 . In addition, the number of projection parts  310  may be one or plural, and when the plurality of projection parts  310  are configured, the plurality of projection parts  310  may be disposed to be spaced apart from each other along an outer circumferential surface of the welding ring  300 . 
     A structure relationship between the manifold  100 , the pipe  200 , and the welding ring  300  will be described in more detail with reference to  FIG.  12   . When the manifold  100 , the pipe  200 , and the welding ring  300  are configured in a cylindrical or ring shape, radii may be formed on the basis of a constant center point O. In this case, the projection part  310  of the welding ring  300  protrudes outward, and thus, a 3-2-th radius R 1 , which is an outer radius of the projection part  310  of the welding ring  300 , may be formed to be greater than a third radius R, which is an outer radius of the welding ring  300 . In addition, at one end of the manifold  100 , a first radius M, which is an outer radius, and a 1-1-th radius M 0 , which is an inner radius, may be formed. Here, the 3-2-th radius R 1  is formed to be smaller than the first radius M but be larger than the 1-1-th radius M 0 , such that the projection part  310  may be seated on one end surface of the manifold  100 . In addition, the third radius R may be formed to have a length smaller than the 1-1-th radius M 0 . Accordingly, when the welding ring  300  is molten, the welding ring  300  is accommodated in the space formed by the inner surface of the second body  102  of the manifold  100  and the outer surface of the pipe  200  as described above, and is entirely exposed to the outside, such that the occurrence of a welding defect may be prevented, and a phenomenon that the molten welding ring  300  overflows to the outside due to the welding ring  300  of the inner portion that is not molten may also be prevented. Here, the outer surface of the pipe  200  may also have a diameter formed as a second radius Y, and the second radius Y may be formed to correspond to the 3-1-th radius R 0 , which is an inner radius of the welding ring  300 . In this case, the 3-1-th radius R 0  may be formed to be greater than the second radius Y in consideration of assemblability. 
     Fourth Embodiment 
       FIGS.  13  and  14    illustrate a pipe connection assembly of a heat exchanger according to a fourth embodiment of the present invention, wherein  FIG.  13    is an exploded perspective view of the pipe connection assembly, and  FIG.  14    is a plan cross-sectional view of the pipe connection assembly. 
     Referring to  FIG.  13   , the pipe connection assembly according to the present invention further includes a connection body  400  connecting the manifold  100  and the pipe  200  to each other. In this case, protrusion parts  410  protruding inward may be formed on an inner surface of an upper end of the connection body  400 , and the welding ring  300  may be seated on one end surfaces of the protrusion parts  410  and may be disposed to surround the outer surface of the pipe  200 . 
     A structure between respective components will be described in more detail with reference to  FIG.  14   . As illustrated in  FIG.  14   , the connection body  400  includes the protrusion parts  410  protruding inward, and an inner side of the connection body  400  and an inner side of the protrusion part  410  may have inner diameters formed as a fourth radius N and a 4-1-th radius N 1 , respectively, on the basis of a certain center point O. Here, the 4-1-th radius N 1  may be formed to be smaller than the fourth radius N. In addition, the welding ring  300  may have a third radius R, which is an outer radius, and a 3-1-th radius R 0 , which is an inner radius, formed on the basis of the center point O, and the 3-1-th radius R 0  may be formed to be smaller than the fourth radius N but greater than the 4-1-th radius N 1 . Accordingly, the welding ring  300  may be seated on the protrusion parts  410  of the connection body  400  and be exposed to the outside. In addition, the 3-1-th radius R 0  is formed to be greater than the second radius Y, which is the outer radius of the pipe  200 , such that the welding ring  300  may be formed to surround the pipe  200 . In addition, a space is formed between an inner surface of an upper end side of the connection body  400  and an outer surface of a lower end side of the pipe  200 , and when the welding ring  300  seated on the protrusion part  410  is molten, the welding ring  300  may be accommodated in the space. Here, a plurality of protrusion parts  410  according to the present invention may be disposed to be spaced apart from each other along an inner circumferential surface of the connection body  400 , and protrusion surfaces of the protrusion parts  410  may be modified into various forms such as a form in which they are parallel to or inclined with respect to one end surface of the connection body  400 . 
     The present invention is not limited to the embodiments described above, and may be applied to various fields. In addition, the present invention may be variously modified by those skilled in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims.