KR20130016999A

KR20130016999A - Evaporator having a defrosting heater installed in a tube and method for manufacturing the same

Info

Publication number: KR20130016999A
Application number: KR1020110079241A
Authority: KR
Inventors: 박지오
Original assignee: 박지오
Priority date: 2011-08-09
Filing date: 2011-08-09
Publication date: 2013-02-19

Abstract

The present invention discloses an evaporator in which a defrost heater is installed in a tube having a plurality of passages, and a method of manufacturing the same. The evaporator of the present invention is composed of a tube, a fin, a defrost heater, a refrigerant return cap and a refrigerant coupling. The tube has a first end and a second end, and includes a first passage, a second passage, and a third passage formed along the longitudinal direction such that the first end and the second end communicate with each other. The pin is spirally wound and fixed to the outer circumferential surface of the tube along the longitudinal direction. The defrost heater is embedded in the first passage. The refrigerant return cap is coupled to the second end such that the second passage and the third passage are connected to each other. The refrigerant coupling is coupled to the first end and includes a refrigerant inlet tube communicating with the second passage and a refrigerant outlet tube communicating with the third passage. According to the present invention, the productivity can be improved and the manufacturing cost can be greatly reduced by a simple structure in which the pin is spirally wound and fixed to the outer surface of the tube. In addition, since the defrost heater is built into the tube, the thermal efficiency and the defrosting efficiency are improved, and local heating of the tube and the fins is prevented, so that a useful effect of reducing the power consumption of the refrigerator and improving the performance can be obtained. have.

Description

Evaporator with a defrost heater installed inside the tube and its manufacturing method {EVAPORATOR HAVING A DEFROSTING HEATER INSTALLED IN A TUBE AND METHOD FOR MANUFACTURING THE SAME}

The present invention relates to an evaporator, and more particularly, to an evaporator having a defrosting heater is installed inside a tube having a plurality of passages and a method of manufacturing the same.

A general vapor compression type refrigerator includes an evaporator, a compressor, a condenser, and an expansion valve. The compressor converts the refrigerant vapor of low temperature and low pressure into refrigerant vapor of high temperature and high pressure and sends it to the condenser. The condenser cools the refrigerant vapor at high temperature and high pressure to radiate heat to a high heat source and condenses it into the refrigerant liquid at high temperature and high pressure. The high temperature and high pressure refrigerant liquid passing through the expansion valve becomes a low temperature low pressure refrigerant liquid to facilitate evaporation. The evaporator absorbs heat from the low heat source while allowing the low temperature low pressure refrigerant liquid (wet steam) to pass through the expansion valve to evaporate the low temperature low pressure refrigerant vapor. The refrigerant vapor evaporated in the evaporator is sent back to the compressor for circulation.

1 and 2 show a conventional evaporator for use in a refrigerator. The evaporator 10 consists of a tube 20, a plurality of fins 30, and a pair of support plates 40, 42. The tube 20 is formed by connecting the ends of a pair of tubes bent in a zigzag shape by welding. Each of the fins 30 is formed with a hole 32 so that the tube 20 can be fitted. The pair of support plates 40 and 42 are mounted on both sides of the bent portion of the tube 20 bent in a zigzag form. The bent portions of the tube 20 are fitted in the holes 44 formed in the respective support plates 40, 42. The low temperature and low pressure refrigerant liquid supplied through the expansion valve absorbs heat and evaporates while flowing inside the tube 20. Fins 30 widen the heat transfer area to allow the endotherm to smoothly occur from a low heat source.

An accumulator 50 is mounted between the outlet of the tube 20 and the compressor. The accumulator 50 receives the mixed low-temperature low-pressure refrigerant liquid and refrigerant vapor, sends the refrigerant vapor to the compressor, stores the refrigerant liquid, and vaporizes the refrigerant liquid by ambient heat to the compressor. In addition, the accumulator 50 sends oil to the compressor through an oil bleeder hole and removes moisture and impurities.

On the other hand, when the refrigerant in the tube 20 is endothermic and evaporated, the temperature of the surface of the tube 20 and the fins 30 is lowered, and water vapor in the air in contact with the surface of the tube 20 and the fins 30 is reduced. Freezing produces Frost. As the frost generated on the surfaces of the tube 30 and the fins 30 grow, it hinders heat transfer and degrades the performance of the evaporator 10. Therefore, the defrost heater 60 is installed in the evaporator 10 to periodically remove frost. Defrost heater 60 is a heating wire (Electrothermal) is inserted into the inside of the heating tube, the heating tube is disposed so that the contact plate 40, 42 and the fin 30 in contact with the tube 20 and the fin 30 The frost generated in the field is melted to maintain the performance of the evaporator 10.

The conventional evaporator shown in Figs. 1 and 2 is very cumbersome and complicated in the assembly process of the tube 20 and the fin 30, and thus the manufacturing cost is high. In particular, a process of inserting the plurality of fins 30 having a hole in a flat plate shape into the tube 20, expanding the tube 20 to bring the fins 30 and the tube 20 into close contact with each other, and the tube 20. Zig-zag bending process after expansion of) is very complicated, so automation is difficult and productivity is low. In addition, there is a problem in that the heat transfer performance is inferior because the close contact between the tube 20 and the fin 30 by the expansion method. In addition, after assembling the tube 20 and the fins 30, the defrost heater 60 must be assembled separately. Therefore, the bent in the shape for assembling the defrost heater 60 in advance, and the seat for fixing the defrost heater 60 to the tube 20 and the fins 30, the manufacturing process is complicated.

On the other hand, since the defrost heater 60 is installed around the tube 20 and the fins 30, heat generated in the defrost heater 60 cannot be uniformly transmitted to the entire tube 20 and the fins 30. Defrost time is long and the energy consumption of the defrost heater 60 is increased. In particular, only the portion of the tube 20 which is located close to or in contact with the defrost heater 60 and the frost adjacent to the fins 30 is removed to remove the frost located away from the defrost heater 60. When the power is continuously applied to the defrost heater 60, the tube 20 and the fins 30 of the portion adjacent to the defrost heater are locally heated. In the domestic refrigerator, when the tube 20 or the fins 30 are locally heated at the time of defrosting, the air heated in the evaporator 10 is supplied to the freezer compartment when the defrosting is completed and the freezing is performed, thereby lowering the efficiency of the freezer. You can also hurt food stored in the refrigerator. In addition, there may be a risk of fire due to local overheating of the defrost heater 60 or failure due to disconnection.

The present invention is to solve various problems of the conventional evaporator as described above. It is an object of the present invention to provide a evaporator of a novel structure that can reduce manufacturing costs and prevent local overheating during defrosting. It is also an object of the present invention to provide a method for manufacturing a new structure of the evaporator which can reduce the manufacturing cost.

According to one aspect of the invention, there is provided an evaporator having a defrost heater installed inside the tube. An evaporator according to the present invention includes a tube having a first passage, a second passage, and a third passage, each having a first end and a second end, and formed along the longitudinal direction such that the first end and the second end communicate with each other. Wow; A pin wound around the outer circumferential surface of the tube in a helical fashion along the longitudinal direction; A defrost heater embedded in the first passage; A refrigerant return cap coupled to the second end such that the second passage and the third passage are connected to each other; And a refrigerant coupling coupled to the first end and having a refrigerant inlet tube communicating with the second passage and a refrigerant outlet tube communicating with the third passage.

The cross-sectional shape of the tube may be circular, and the first passage, the second passage, and the third passage may be formed by forming a pair of partition walls inside the tube. In addition, the cross section of the tube is circular, the first passage is formed by the inner tube of the circular cross-section concentric with the tube, the second passage and the third passage is formed by connecting a pair of partition walls connecting the inner tube and the tube. You may.

In addition, the fin is wound around the outer circumferential surface of the tube at regular intervals, and the first end portion has a plurality of straight portions arranged in parallel with the tube and a plurality of curved portions connecting two adjacent straight portions among the plurality of straight portions. It is preferable to bend in a zigzag shape toward the two ends. At this time, the pins adjust the distance between the pins so as to be located only in the straight portion.

When the inner wall of the refrigerant return cap is coupled to be spaced apart from the second end of the tube, the first plug is sealed in the first passage so as to be adjacent to the second end, and the second passage and the third passage communicate with each other. can do. When the inner wall of the refrigerant return cap is in close contact with the second end of the tube, the second passage and the third passage are in close contact with each other, and a part of the partition wall partitioning the second passage and the third passage is removed to remove the second passage. And the third passage communicates with each other.

In addition, a part of the defrost heater insertion hole may be formed by removing a portion of the outer peripheral surface of the tube adjacent to the first end to insert the defrost heater into the first passage. In order to facilitate zigzag bending of the tube, it is preferable to form grooves or protrusions on the outer circumferential surface of the tube for guiding the bending direction along the longitudinal direction.

Evaporator according to the present invention is characterized by the following technical configuration. First, the defrost heater is accommodated in the first passage formed inside the tube. Second, a fin is wound spirally on the outer circumferential surface of the tube. Third, the second passage and the third passage inside the tube are connected at the second end to communicate with each other so that the refrigerant supplied to the second passage is returned to the third passage.

An evaporator having the above technical features provides the following effects. First, the manufacturing process of the evaporator is simplified to facilitate automation. The conventional evaporator was prepared by inserting a plurality of fins in the tube at regular intervals, bending the tube in zigzag to prepare a tube assembly, and bending and combining the defrost heater to match the shape of the tube zigzag. According to the present invention, the defrost heater bending process and the assembly process can be omitted by simultaneously bending the tube and the defrost heater in a zigzag state at a time while the defrost heater is inserted into the first passage of the tube, thereby improving productivity. Secondly, since the fins are continuously wound on the outer circumferential surface of the tube to be coupled in a spiral manner, the process of pressing the plurality of plate-shaped fins, inserting them into the tube, and expanding the tube may be omitted. Third, the tube having three passages may be extruded and then bent zigzag only once. A conventional evaporator was produced by bending two tubes in zigzag, respectively, and then welding the ends to return the refrigerant. Fourth, since the defrost heater is inserted into the first passage of the tube, the efficiency of the defrost heater is improved. Conventional defrost heater is coupled to the evaporator to contact a portion of the tube or fin structure does not uniformly heat the tube or fin, but the evaporator according to the present invention is inserted into the passage of the metal tube to be installed in contact with the tube It is. Therefore, the defrost heater uniformly heats the tube, and the heat of the heated tube is uniformly transferred to the fin to shorten the defrost time. In addition, the tubes or fins are not locally heated, so that when used in a home refrigerator, the food stored in the refrigerator compartment can be prevented from spoiling.

According to another aspect of the present invention, there is provided a method for producing an evaporator having a defrost heater installed inside the tube. The method of manufacturing an evaporator according to the present invention comprises the steps of: producing a tube by extruding a metal material such that a first passage, a second passage and a third passage are formed along the longitudinal direction; Removing a part of the outer peripheral surface of the tube adjacent to the first end to form a defrost heater insertion hole; Spirally winding a plurality of fins at regular intervals on an outer circumferential surface of the tube, and coupling a refrigerant return cap to the first end to connect the second passage and the third passage; Bonding the tube, the plurality of fins and the refrigerant return cap by brazing; Inserting the defrost heater into the first passage through the defrost heater insertion hole; Bending the portion where the plurality of fins are not spirally wound such that the tube is zigzag-shaped.

In the manufacturing method of the evaporator according to the present invention, the fins are wound around the outer circumferential surface of the tube at regular intervals, the defrost heater is inserted into the first passage of the tube, and the tube and the defrost heater are simultaneously bent in zigzag. Therefore, automation is easy by simplifying the conventional complicated manufacturing process. In addition, by providing an evaporator with a built-in defrost heater provides an evaporator with improved thermal efficiency and defrosting efficiency.

The evaporator according to the present invention can improve productivity and greatly reduce the manufacturing cost by a simple structure in which the pin is spirally wound and fixed to the outer circumferential surface of the tube. In addition, since the defrost heater is built into the tube, the thermal efficiency and the defrosting efficiency are improved, and local heating of the tube and the fins is prevented, so that a useful effect of reducing the power consumption of the refrigerator and improving the performance can be obtained. have. In addition, there is an effect that can be easily automated by a series of processes such as extrusion of the tube, winding and brazing of the fin, built-in defrost heater, bending of the tube.

1 is a perspective view showing the configuration of a conventional evaporator.
FIG. 2 is a front view showing the configuration of the evaporator shown in FIG. 1.
3 is an exploded perspective view of one embodiment of an evaporator according to the present invention.
4 is a front view of the evaporator embodiment shown in FIG. 3.
5 is a partial cross-sectional view showing the configuration of the tube and the fin in the evaporator according to the present invention.
FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. 5.
7 is a partial perspective view showing one embodiment of a tube and a refrigerant return cap of an evaporator according to the present invention.
8 is a partial perspective view showing an embodiment of a tube, a defrost heater and a refrigerant coupling of the evaporator according to the present invention.
9 is a partial cross-sectional view for explaining the flow of the refrigerant in the evaporator according to the present invention.
10 is a view showing another embodiment of an evaporator according to the present invention.
11 shows another embodiment of a tube in an evaporator according to the invention.
12 shows another embodiment of a tube in an evaporator according to the invention.
Figure 13 shows another embodiment of a tube in an evaporator according to the invention.
14 to 17 are views for explaining the manufacturing method of the evaporator according to the present invention.

Other objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments with reference to the accompanying drawings.

Hereinafter, preferred embodiments of the evaporator according to the present invention will be described in detail with reference to the accompanying drawings.

3 to 6, the evaporator 100 according to the present invention includes a tube 110 for the flow of refrigerant, fins 140 spirally wound on the outer circumferential surface of the tube 110, and the tube 110. And a refrigerant return cap 160, a refrigerant coupling 170, and a defrost heater 150, which are coupled to both ends.

The tube 110 has a first end 112 and a second end 114 disposed opposite the first end 112. The tube 110 includes a plurality of straight portions 116 and a plurality of curved portions 118 alternately connecting two adjacent straight portions 116 among the plurality of straight portions 118 on both sides. do. The tube 110 is connected from the first end 112 to the second end 114 such that the plurality of straight portions 116 and the plurality of curved portions 118 form a zigzag shape.

Three passages 120a, 120b, and 120c are formed along the longitudinal direction inside the tube 110. The passages 120a, 120b and 120c are partitioned by two partitions 122a and 122b which are formed along the longitudinal direction inside the tube 110. Mark 124 is formed on the outer circumferential surface of the tube 110 to guide the bending direction for forming the curved portion 118 of the tube 120 along the longitudinal direction. The mark 124 may be provided by forming a groove 126 or a protrusion (not shown) in the longitudinal direction on the outer circumferential surface of the tube 110. In the embodiment shown in Figure 6, the cross section of the tube 110 is shown to be formed in a circular shape, but is not limited to this, the cross section of the tube 110 is configured in a variety of shapes, such as rectangular, square, oval, polygonal, if necessary can do. The tube 100 is manufactured by extrusion using an aluminum alloy or a copper alloy having good thermal conductivity, but is not limited thereto.

8 and 9, the defrost heater insertion hole 128 is formed in the wall of the tube 110 forming the first passage 120a, but optionally, the second passage 120b or It may be formed on the wall of the tube 110 forming the three passage (120c). That is, the defrost heater insertion hole 128 may be formed by removing any one of the three passages and a part of the wall of the tube 100 forming the passage. In addition, although the defrost heater insertion hole 128 was formed in the vicinity of the first end 112 in this embodiment, it can also be selectively formed in the vicinity of the 2nd end 114 as needed.

3 to 5, the evaporator 100 of the present embodiment includes a plurality of fins 140 that are spirally wound and fixed along an outer circumferential surface of the tube 110 in order to increase a heat transfer area with air. In manufacturing as described below, in the present embodiment, the fins 140 are spirally wound on the straight portions 116 of the tube 110, and the curved portions 118 are not spirally sensed by the curved portions 118. The fin 140 is formed by spirally winding the outer circumferential surface of the tube 110 while continuously supplying a band-shaped aluminum alloy strip. The spiral wound spiral spiral 140 is composed of a coupling portion 146 formed by bending one side of the strip to be coupled to the outer circumferential surface of the tube 110 by brazing, and an unbent pin portion 142. The fin 140 uses an aluminum alloy or a copper alloy having good thermal conductivity, but is not limited thereto.

3, 8 and 9, a defrost heater 150 for removing frost generated on the surface of the tube 110 and the fin 140 during the operation of the evaporator 100 includes a first passage 120a. Is built in. The defrost heater 150 is a device that generates heat by receiving electricity. The defrost heater 150 includes an insulated heating unit 152 and a terminal 154 connected to supply electricity to the heating unit 152. The terminal 154 is exposed to the outside of the tube 110 through the defrost heater insertion hole 128 and is connected to a power connector 156. In this embodiment, the defrost heater 150 is inserted into the first passage located between the second passage (120b) and the third passage (120c), the tube 110 and the fin 140 is uniformly heated to defrost time Can shorten. The defrost heater 150 may be installed to be in close contact with the inner circumferential surface of the first passage 120a so that heat transfer may occur effectively. In addition, first and second plugs 180 and 182 are inserted and coupled to both ends of the first passage 120a into which the defrost heater 150 is inserted. The first and second plugs 180 and 182 are coupled to close the first passage 120a to prevent the refrigerant liquid from leaking into the first passage 102a. The first plug 180 is fitted in the first passage 120a so as not to completely close the defrost heater insertion hole 128. The tube 110 and the first and second plugs 180 and 182 are coupled to each other to be kept airtight by brazing.

3, 4, 7 and 9, a refrigerant return cap 160 is coupled to the second end 114 of the tube 110, and the second end 114 is inserted. Bore 162 is provided. An inner circumferential surface of the bore 162 is formed with a step 162a to engage the second end 114. The bore of the refrigerant return cap 160 includes a channel 164 for connecting the second passage 120b and the third passage 120c to communicate with each other. In this embodiment, the channel 164 is formed by the space between the second plug 182 and the refrigerant return cap 160. However, when the second plug 182 is integrally formed with the refrigerant return cap 160, The second plug 182 may be formed by forming holes or removing side surfaces. The tube 110 and the refrigerant return cap 160 are combined to be hermetically maintained by brazing.

3, 4, 8, and 9, a refrigerant coupling 170 is coupled to the first end 112 of the tube 110. The refrigerant coupling unit 170 includes a refrigerant inlet pipe 174 for supplying the refrigerant liquid supplied from the expansion valve to the evaporator and a refrigerant outlet for supplying the refrigerant vapor discharged from the evaporator to the condenser. pipe: 176). The first end 112 of the tube 110 is inserted into the bore 172 of the refrigerant coupling 170. Referring to FIG. 9, the first end 112 of the tube 110 and the refrigerant coupling 170 are coupled to each other to be hermetically maintained by brazing, and the refrigerant inlet pipe 174 is connected to the second passage. The refrigerant outlet pipe 176 is disposed to communicate with the 120b, and the refrigerant outlet pipe 176 is arranged to communicate with the third passage 120c. The refrigerant inlet pipe 174 is connected by an expansion valve and a pipeline, and the refrigerant outlet pipe 176 is connected by a compressor and a pipeline. In the present embodiment, the first plug 180 is separately formed from the refrigerant coupling 170 and inserted into the first passage 120a. However, the first plug 180 is in close contact with the inner surface of the refrigerant coupling 170 to maintain the airtightness. When brazing, the first plug 180 does not need to be installed. In addition, in order to simplify the assembly process, the first plug 180 may be integrally formed with the refrigerant coupling 170.

As shown in FIGS. 3 and 4, the evaporator 100 according to the present invention prevents the linear portions 116 of the tube 110 from moving relatively, and the linear portions 116 to facilitate installation. It further comprises a pair of support plates 190, 192 coupled to oppose both sides of the). The plurality of holes 194 for fitting the curved portions 118 or the straight portions 116 into which the pin 140 is not wound is formed in the support plates 190 and 192 at regular intervals. The shape of the evaporator 100 is maintained by the straight portions 116 being fitted into and fixed to the holes 194 of the support plates 190 and 192. The holes 194 are configured in the form of a slot into which two adjacent straight portions 116 can be fitted. The first and second ends 112 and 114 of the tube 110 are inserted into and fixed to the holes 196a and 196b formed in the upper and lower portions of the support plate 190.

4 and 9, the operation of the evaporator 100 of the present embodiment will be described. The refrigerant inlet pipe 174 and the refrigerant outlet pipe 176 are connected to the expansion valve and the compressor, respectively, not shown. The low temperature and low pressure refrigerant liquid supplied from the expansion valve flows into the second passage 120b through the refrigerant inlet pipe 174 and flows toward the second end portion 114 to absorb heat and become refrigerant vapor. The refrigerant vapor and the refrigerant liquid not evaporated pass through the second passage 120b and flow back into the third passage 120c through the channel 164 of the refrigerant return cap 164 and along the third passage 120c. As it flows, it continuously absorbs heat, becomes refrigerant vapor, is discharged into the refrigerant outlet pipe 176, and sent to the compressor.

The tube 110 and the fins 140 fixed to the tube 110 are deprived of heat when the refrigerant liquid evaporates, thereby lowering the temperature and lowering the temperature of externally contacted air. When the outside air temperature which is in contact with the fin 140 is lowered, water vapor in the air is cooled to become frost and stick to the surfaces of the fin 140 and the tube 110 to interfere with heat transfer. If heat transfer is interrupted by frost, the performance of the evaporator is reduced, so that the defrost heater is operated. When power is supplied to the defrost heater, heat is generated in the heat generating unit, and the generated heat is transferred to the tube 110 in close contact with the heat generating unit by thermal conduction. The tube 110 is uniformly heated by the heat conduction from the heat generating unit, and the fins 140 in close contact with the tube 110 are also uniformly heated by the heat conduction from the tube 110. Therefore, the temperature of the evaporator 100 is prevented from being locally increased by the defrost heater, so that the defrosting efficiency of the evaporator 100 is improved and the defrosting time can be shortened. In addition, when the evaporator according to the present invention is used in a refrigerator, it prevents the air heated by the local heating of the evaporator or the heated defrost heater from flowing into the freezer compartment, thereby preventing the food stored in the freezer compartment from being damaged, and the consumption of the refrigerator. Power is reduced.

10 shows another embodiment of a tube and a refrigerant return cap used in the evaporator according to the present invention. The embodiment shown in FIG. 10 is different from the embodiment shown in FIG. 9 in that the first passage 120a into which the defrost heater 150 is inserted is disposed outside of the first passage 120a so that the defrost heater 150 is not disposed in the center of the first passage 120a. The plug for closing both ends is not used, and the defrost heater insertion hole 178 is formed in the refrigerant coupling cap 170. In addition, the channel 168 of the refrigerant return cap 160 is formed by removing a part of the partition wall 122b between the second passage 120b and the third passage 120c.

Referring to FIG. 10, the first through third passages 120a, 120b, and 120c of the tube 110 are formed along the longitudinal direction of the tube 110 by the partition walls 122a and 122b. The second end 114 is inserted into the bore 162 of the refrigerant return cap 160. The second end 114, the second passage 120b, and the third passage 120c are in close contact with the inner wall 166 of the bore 162. In addition, in order to connect the second passage 120b and the third passage 120c to communicate with each other, a channel 168 in which a portion of the second partition wall 122b of the second end 114 is removed is formed. The channel 168 may be formed by forming a hole in the second partition 122b. The coolant liquid flows through the second passage 120b and the channel 168 to the third passage 120c.

The first end 112 of the tube 110 is inserted into the bore 172 of the refrigerant coupling 170. The refrigerant inlet pipe 174 of the refrigerant coupling 170 communicates with the second passage 120b, and the refrigerant outlet pipe 176 communicates with the third passage 120c. The defrost heater 150 is embedded in the first passage 120a. The defrost heater 150 is inserted into the first passage 120a through the defrost heater insertion hole 178 of the refrigerant coupling 170.

In the evaporator 100 according to the present invention, the passages 120a, 120b, and 120c of the tube 110 may be changed in various shapes and structures. In figure 11 another embodiment of a tube in an evaporator according to the invention is shown. The tube 110 of the embodiment shown in FIG. 11 has a configuration for more actively evaporating the refrigerant liquid in the passages 120a, 120b, 120c partitioned by the partition walls 122a, 122b. That is, the concave-convex 130 for extending the surface area of each of the inner peripheral surfaces of the second and third passages 120b and 120c is formed in the longitudinal direction. When the surface areas of the inner surfaces of the second and third passages 120b and 120c are widened, the area of heat transfer from the tube 110 to the refrigerant liquid is widened, thereby improving the efficiency of the evaporator.

12 shows another embodiment of a tube in an evaporator according to the invention. The tube 110 of the embodiment shown in FIG. 12 has a first passage 120a by an inner tube having a circular cross section. The inner tube 132 is formed to be concentric with the tube 110 inside the tube 110. The first passage 120a is partitioned from the second and third passages 120b and 120c by the inner tube 132. The inner tube 132 is connected to the inner circumferential surface of the tube 110 by a pair of partition walls 134a and 134b. The second and third passages 120b and 120c are partitioned by partition walls 134a and 134b. The defrost heater 150 is fitted in the first passage 120a. As such, the passages 120a, 120b, and 120c are partitioned by the inner tube 132 and the partition walls 134a and 134b to minimize the cross-sectional area of the first passage 120a for the installation of the defrost heater 150. And the cross-sectional areas of the second and third passages 120b and 120c for the flow of the refrigerant to a maximum size.

In figure 13 another embodiment of a tube in an evaporator according to the invention is shown. In the embodiment shown in FIG. 13, a plurality of unevennesses 136 are formed on the inner circumferential surfaces of the second and third passages 120b and 120c to widen the surface area of the tube of the embodiment shown in FIG. 12.

With reference to FIGS. 14-17, the manufacturing method of the evaporator 10 which concerns on this invention is demonstrated.

Referring to FIG. 10, first, the tube 110 is manufactured into a linear member having a long length by extruding a metal material having excellent thermal conductivity, for example, an aluminum alloy. At this time, it is preferable to form a groove 126 for guiding the direction when the tube is bent on the outer circumferential surface of the tube by using an extrusion die. Referring to FIG. 11, the plurality of fins 140 are spirally wound around the outer circumferential surface of the tube 110 manufactured by extrusion at regular intervals. At this time, a brazing filler metal is applied to the outer peripheral surface of the tube 110 and the coupling portion 146 of the fin 140 for brazing. The pins 140 are wound only on the straight portions 116 without sensing the portion to be the curved portion 118 by bending. The method and apparatus for spirally winding the fins 140 on the outer circumferential surface of the tube 110 are omitted in the known art.

Referring to FIG. 12, the second end 114 of the tube 110 is then fitted into the bore 162 of the refrigerant return cap 160, and the first end 112 of the tube 110 is coupled to the refrigerant. Fit into bore 172 of ring 170 (refrigerant return cap and refrigerant coupling in the case of the embodiment shown in FIG. 14). At this time, the brazing filler metal for brazing is applied between the inner circumferential surface of the first passage 120a and the outer circumferential surfaces of the first and second plugs 180 and 182, and between the outer circumferential surface of the tube 110 and the inner circumferential surface of the bores 162 and 172. do. In the case where the refrigerant return cap and the cold casing coupling use those of the embodiment shown in FIG. 14, the tube 110 is inserted after the first and second plugs 180 and 182 are inserted into both ends of the first passage 120a in advance. The both ends of the) is inserted into the refrigerant return cap 160 and the refrigerant coupling 170 to be assembled. Next, the tube 110 in which the refrigerant return cap 160 and the refrigerant coupling 170 are assembled is introduced into a brazing furnace, and the fin 140 and the refrigerant return cap 160 are inserted into the tube 110. And the refrigerant coupling 170 are fully coupled by brazing. Conveyors can be installed in the brazing furnace so that the assembled products can be continuously brazed.

Next, the defrost heater 150 is inserted into the first passage 120a of the tube 110 through the defrost heater insertion hole 128. At this time, the terminal 154 is exposed to the outside of the defrost heater insertion hole (128).

Next, the defrost heater 150 is bent in a zigzag shape, as shown in Figure 13 the straight tube 110 inserted into the first passage (120a). The tube 110 is bent using a pipe bending machine. The groove 124 formed on the outer circumferential surface of the tube 110 serves as a reference line for holding the bending direction when the tube 110 is bent by the bending machine. The worker bends the tube 110 precisely with respect to the groove 124. When bending of the tube 110 is completed, the straight portions 116 are fitted into the holes 194 of the support plates 190 and 192 to complete the shape of the evaporator. In the manufacturing method of the evaporator according to the present invention, since the defrost heater 150 is inserted and bent at the same time inside the tube 110, the process of simplifying the bending process and assembling the defrost heater to the bent tube is omitted. Automation is easy and productivity is improved. In addition, the fin 140 is formed by spirally winding the outer circumferential surface of the tube, and by applying a brazing filler metal while winding the fin, the manufacturing process is simplified, so that automation is easy and productivity is improved.

The embodiments described above are merely described with reference to the preferred embodiments of the various embodiments of the present invention, and those skilled in the art to modify the embodiments in various forms by changing, modifying or replacing the disclosed embodiments. It is to be understood that such modifications are possible and are within the scope of the present invention.

100: evaporator 110: tube
120a, 120b, 120c: passageway 122a, 122b: partition wall
128: Defrost heater insertion hole 130, 136: Unevenness
132: inner tube 140: pin
150: defrost heater 152: heat generating unit
160: refrigerant return cap 164: channel
170: refrigerant coupling 174: refrigerant inlet pipe
176: refrigerant outlet pipe 180: first plug
182: second plug 190, 192: support plate

Claims

A tube having a first end and a second end, the tube including a first passage, a second passage, and a third passage formed along a longitudinal direction such that the first end and the second end communicate with each other;
A pin wound around the outer circumferential surface of the tube in a helical manner along the longitudinal direction;
A defrost heater embedded in the first passage;
A refrigerant return cap coupled to the second end to connect the second passage and the third passage;
A defrost heater coupled to the first end, the defrost heater being provided inside the tube including a refrigerant inlet tube communicating with the second passage and a refrigerant coupling tube communicating with the third passage; evaporator.

The method of claim 1,
And a first plug inserted into the first passage so as to approach the second end, wherein the refrigerant return cap has a bore into which the second end is inserted, and the second passage and the inner peripheral surface of the bore. An evaporator having a defrost heater provided inside the tube in which the end to which the second end is formed is formed to form a channel connecting the third passage.

The method of claim 2,
In order to insert the defrost heater into the first passage, the outer peripheral surface of the tube adjacent to the first end is provided with a defrost heater installed inside the tube in which a part of the defrost heater insertion hole is formed. One evaporator.

The method of claim 3,
An evaporator having a defrost heater installed inside the tube further comprising a second plug inserted into the first passage so as to be adjacent to the first end.

The method of claim 1,
The refrigerant return cap has an inner wall which is in close contact with the second end, and a portion of the partition wall partitioning the second passage and the third passage is removed so that the second passage and the third passage communicate with each other. Evaporator with a defrost heater installed inside.

The method according to any one of claims 1 to 5,
The tube is bent in a zigzag shape from the first end to the second end so as to have a plurality of straight portions arranged in parallel and a plurality of curved portions connecting two adjacent straight portions among the plurality of straight portions. It is,
The fin is an evaporator having a defrost heater installed inside the tube is wound spirally only in the straight portion.

The method according to claim 6,
An evaporator having a defrost heater provided on the inside of the tube is formed on the outer peripheral surface of the tube for guiding the bending direction along the longitudinal direction.

The method according to claim 6,
An evaporator having a defrost heater installed inside the tube, further comprising a pair of support plates provided to support both sides of the plurality of straight portions to fix the plurality of straight portions.

The method according to any one of claims 1 to 5,
The tube has a circular cross section, and the first passage, the second passage and the third passage are provided with a defrost heater provided inside the tube partitioned by a pair of partition walls formed inside the tube. One evaporator.

10. The method of claim 9,
The tube is bent in a zigzag shape from the first end to the second end so as to have a plurality of straight portions arranged in parallel and a plurality of curved portions connecting two adjacent straight portions among the plurality of straight portions. It is,
The fin is an evaporator having a defrost heater installed inside the tube is wound spirally only in the straight portion.

The method according to claim 1 or 2,
The tube has a circular cross section, and the first passage is formed by an inner tube having a circular cross section concentric with the tube, and the second passage and the third passage connect the inner tube and the tube. An evaporator having a defrost heater installed inside a tube partitioned by a pair of partition walls.

The method of claim 11,
The tube is bent in a zigzag shape from the first end to the second end so as to have a plurality of straight portions arranged in parallel and a plurality of curved portions connecting two adjacent straight portions among the plurality of straight portions. It is,
The fin is an evaporator having a defrost heater installed inside the tube is wound spirally only in the straight portion.

Manufacturing a tube by extruding a metal material to form a first passage, a second passage, and a third passage along the longitudinal direction;
Removing a part of the outer peripheral surface of the tube adjacent to the first end to form a defrost heater insertion hole;
Spirally winding a plurality of fins at regular intervals on an outer circumferential surface of the tube;
Coupling a refrigerant return cap to the first end such that the second passage and the third passage are connected to each other;
Bonding the tube, the plurality of fins and the refrigerant return cap by brazing;
Inserting a defrost heater into the first passage through the defrost heater insertion hole;
And bending the portion in which the plurality of fins are not wound in a spiral manner so that the tube is zigzag-shaped.

The method of claim 13,
A refrigerant coupling having a refrigerant inlet tube communicating with the second passage and a refrigerant outlet tube communicating with the third passage at the first end before brazing the tube, the plurality of fins and the refrigerant return cap; Method of manufacturing an evaporator having a defrost heater installed inside the tube further comprising the step of coupling.